Quantitative assessment of the muscles of the rotator cuff with magnetic resonance imaging

Accelerating Efficiency in Arthroscopically Assisted Lower Trapezius Transfer: How Can We Shorten the Learning Curve?

INTRODUCTION

Arthroscopic lower trapezius tendon transfer (aLTT) is an effective strategy to treat massive rotator cuff tears by dynamically restoring the posterior aspect of the rotator cuff force couple and improving range of motion, strength, pain, and stability. aLTT is technically challenging with higher complication rates, and its learning curve has yet to be defined. We aimed to establish a learning curve for aLTT through trends in surgical time, postoperative outcomes, and complications. We hypothesized that increased surgeon experience would be associated with decreased surgical time, improved outcomes, and reduced complication rates.

METHODS

All patients who underwent primary aLTT at our institution between October 2018 and November 2022 were identified and included. Perioperative data, including diagnosis, operative time, complications, revisions, postoperative functional data, and patient-reported outcomes, were recorded and analyzed. A shoulder and elbow fellowship-trained surgeon's learning curve was determined using linear regression and cumulative sum (CUSUM) analyses. The CUSUM analysis evaluated objective differences in surgical time over the surgeon's course of practice and elucidated the completion of the learning curve.

RESULTS

Thirty-nine patients were included, with an average follow-up of 29 months. Mean surgical time was 163 minutes, with a linear decrease in surgical time throughout the study. CUSUM analysis of surgical times demonstrated a learning curve of 14 patients. When comparing the first 14 patients to the remaining 25, no difference was found in range of motion, American Shoulder and Elbow Surgeon score, and subjective shoulder value score, whereas visual analog scale pain scores at the final follow-up decreased in the proficiency phase.

CONCLUSION

This study found a notable linear decrease in surgical time and the number of cases completed without associated detriment to postoperative outcomes. At least 14 cases were required to exit the "learning phase." Further work is needed to find superior metrics to assess proficiency.

LEVEL OF EVIDENCE

4, case series.

Adipose stromal cells in the human rotator cuff are resistant to fibrotic microenvironmental cues

Rotator cuff tears are the most common upper extremity orthopaedic injury, causing degenerative changes within the bone, tendon, joint capsule, bursa and muscle. These degenerative changes are linked to poor rehabilitative and surgical outcomes, which has launched investigations into co-therapeutic biologics. Specifically, mesenchymal stem cells (MSCs) have shown promise in mitigating degenerative changes in animal models of rotator cuff tears, but reports of their impact on clinical outcomes remain mixed. Here we describe an alternative source of MSCs in the human shoulder, adipose stromal cells (ASCs) from the subacromial fat (SAF) pad. Compared to the gold-standard subcutaneous (SQ) fat, we show that SAF ASCs are less sensitive to chemical and mechanical fibrotic cues, (1) retaining smaller cell area with reduced actin stress fibre alignment across a range of physiological and pathological stiffnesses, (2) having reduced traction forces and extracellular matrix production, and (3) having reduced myofibroblastic conversion in response to cytokine challenge. Furthermore, we show that SAF ASCs enhance fusion of primary human myoblasts via paracrine signalling. Despite a fibrotic signature in SAF from rotator cuffs with tendon tears, SAF ASCs sourced from torn rotator cuffs were equally effective at resisting fibroblastic conversion and promoting myogenesis as those from intact rotator cuffs, further supporting autologous clinical use of these cells. In conclusion, this study describes human SAF ASCs as an alternative, and potentially superior, cell source for rotator cuff therapies. KEY POINTS: Adipose tissue within the rotator cuff is a novel and understudied source of therapeutic adipose stromal cells. Here, we detail the impact rotator cuff tears have on adipose tissue within the shoulder, its resident adipose stromal cells, and make a comparison of shoulder adipose stromal cells to subcutaneous adipose stromal cells. Rotator cuff tears cause fibrosis of rotator cuff adipose tissue; this fibrosis does not impact downstream adipose stromal cell morphology or pro-myogenic signaling. Rotator cuff adipose stromal cells resist fibrotic microenvironmental cues and have enhanced pro-myogenic paracrine signaling compared with traditional subcutaneous adipose stromal cells. Rotator cuff adipose stromal cells represent a new cell type that can be impactful in advancing rotator cuff therapies.

Bridging Reconstruction With Interpositional Dermal Allograft Has Superior Healing Than Does Maximal Repair for Treatment of Large to Massive, Irreparable Rotator Cuff Tears-Secondary Analysis of a Randomized Control Trial

PURPOSE

To compare the radiographic results of bridging rotator cuff reconstruction (BRR) with dermal allograft and maximal repair for large or massive, irreparable rotator cuff tears.

METHODS

This was a secondary analysis of data from a single-center, blinded-observer, randomized controlled trial that examined clinical outcomes of BRR compared with maximal repair. A sample size of 30 patients with magnetic resonance imaging (MRI)-proven large or massive (>3 cm), retracted rotator cuff tears and/or involvement of 2 or more tendons were randomly allocated to 1 of 2 groups: maximal repair or BRR using dermal allograft. MRIs were obtained preoperatively and 1 year postoperatively. The primary outcome of this study was the retear rate on MRI. Secondary outcomes included progression of muscle atrophy and fatty infiltration.

RESULTS

There was no difference in age or preoperative tear size between the 2 groups. Patients treated with BRR had decreased retear rate (21%) compared with patients who received maximal repair alone (87%). There was no difference in the number of patients who had progression of muscle atrophy (P = .088 for supraspinatus and P = .738 for infraspinatus) or fatty infiltration (P = .879 for supraspinatus and P = .693 for infraspinatus) between the 2 groups. A significant increase in mean postoperative supraspinatus muscle atrophy was identified in the maximal repair group (P = .034).

CONCLUSIONS

The results of this secondary analysis of a randomized controlled trial comparing radiographic results of maximal repair versus BRR using dermal allograft in the treatment of large or massive rotator cuff tears show that BRR results in a significantly reduced structural failure rate and a trend toward better preservation of supraspinatus muscle mass compared with maximal repair.

LEVEL OF EVIDENCE

Level I, secondary analysis of a randomized controlled trial.

Factors associated with pseudoparalysis in patients with extensive chronic and atraumatic rotator cuff injury

BACKGROUND

Patients with massive chronic atraumatic rotator cuff injuries can be asymptomatic or present severe shoulder dysfunction, a condition known as pseudoparalysis. Our hypothesis is that integrity of the subscapularis, hypertrophy of the teres minor, and a complete tear of the long head of the biceps tendon are associated with improved active forward flexion range in such patients. Therefore, the objective of this study was to evaluate factors associated with pseudoparalysis.

METHODS

This was a single-center cross-sectional study that included patients with massive chronic atraumatic rotator cuff injuries. Range of motion of the affected shoulder, demographic data, specific tests for rotator cuff assessment, and imaging studies were collected.

RESULTS

A total of 68 patients (71 shoulders) were included in the study. At initial evaluation, 41 patients exhibited active forward flexion of the shoulder greater than 90° (No Pseudoparalysis group). Patients with active forward flexion less than 90° (n = 29) underwent subacromial injection of local anesthetic and were then reevaluated. In 15 patients the pseudoparalysis was resolved (False Pseudoparalysis group), and 14 maintained active forward flexion of less than 90° (True Pseudoparalysis group).

CONCLUSION

We concluded that the presence of a shoulder shrug sign, Goutallier grade III and IV fatty infiltration, and a full-thickness tear of the subscapularis were risk factors for the occurrence of pseudoparalysis. Tear extension, as described by Wieser et al, also demonstrated statistical difference between groups, with greater anterior tear extension (involvement of subscapularis tendon) and greater global tear extension observed in the True Pseudoparalysis group.

Qualitative analysis of the supraspinatus muscle fatty infiltration on MRI: correlation of the tangent sign with Goutallier grade at the Y view and medial scapular border in large retracted rotator cuff tears

BACKGROUND

Surgically repairing rotator cuff tears with a higher extent of fatty infiltration (FI) is controversial. Current evidence supports performing rotator cuff repair in patients exhibiting Goutallier stage 3-4 FI. However, the presence of retraction complicates accurate assessment using the Goutallier Classification, particularly on the lateral Y-view. A shift toward classifying FI in more medial regions may enhance the precision of tissue quality quantification. The objective of this study was to analyze the uniformity of FI within the entire supraspinatus muscle using the Goutallier Classification across 3 scapular Y-view sections and to examine the association between Goutallier grade, tangent sign, and modified Patte stage.

METHODS

A retrospective evaluation was conducted on preoperative magnetic resonance imaging scans from a consecutive series of 97 patients who had previously undergone arthroscopic rotator cuff repairs. Three supraspinatus sections on the magnetic resonance imaging sagittal plane were identified: the lateral Y-view (section 1), a medial section at the suprascapular notch anatomical landmark (section 2), and a section 3 cm medial from the suprascapular notch Medial Scapular Body (section 3). Goutallier grade, tangent sign, and modified Patte stage were used to evaluate FI, muscle atrophy, and tendon retraction, respectively.

RESULTS

Section 1 had the highest Goutallier grade, while section 3 had the lowest. Intraobserver rest retest reliability analysis showed excellent consistency in all sections with section 2 (intraclass correlation coefficient [ICC] = 0.920, 95% confidence interval [CI]), section 2 (ICC = 0.917, 95% CI), and section 3 (ICC = 0.923, 95% CI) for Goutallier grade. Interobserver reliability analysis also revealed excellent consistency in section 1 (ICC = 0.951, 95% CI), section 2 (ICC = 0.949, 95% CI), and section 3 (ICC = 0.922, 95% CI) for Goutallier grade. A strong correlation was observed between Goutallier grade and modified Patte stage (τb = 0.43-0.56, P = .001), and between Goutallier grade and tangent sign (τb = 0.43-0.54, P = .001) across all sections.

CONCLUSION

The severity of FI within the supraspinatus muscle belly is inconsistent, with the lateral portion being the most severe and the medial portion the least severe. Goutallier grade demonstrates a strong correlation with tangent sign and modified Patte stage. This suggests that tendon retraction results in a potential overestimation in the amount of FI defining some tears unjustly irreparable when measuring at the traditionally described lateral Y-view position compared with 3 cm medial.

A Quantitative Fatty Infiltration Evaluation of the Supraspinatus Muscle: Enhanced Clinical Relevance and Improved Diagnostic Value on Predicting Retear Compared With the Goutallier Classification

BACKGROUND

Preoperative assessment of fatty degeneration is important for managing rotator cuff tears. The Goutallier classification is semiquantitative and observer dependent. Discrepancies among surgeons can be prominent. A quantitative method may improve accuracy and reliability in evaluating the exact percentage of fatty infiltration (Fat%).

HYPOTHESIS/PURPOSE

This study aimed to investigate the correlation between the new quantitative method and the Goutallier classification in assessing fatty infiltration (FI) of the supraspinatus muscle and to explore the use of this method in predicting retear after rotator cuff repair. It was hypothesized that the new method would significantly correlate with the Goutallier classification and be more sensitive to retear.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence; 3.

METHODS

This study included 105 patients who underwent arthroscopic rotator cuff repair for large to massive tears. All patients underwent routine preoperative and 1-year postoperative magnetic resonance imaging and were divided into 2 groups according to tendon healing. Preoperative quantitative Fat% of the supraspinatus muscle was evaluated based on the signal intensity (SI) of the T1-weighted sequence. The Fat% was calculated using the following equation: SIsupraspinatus = SIfat× Fat% + SImuscle× (1 - Fat%). The correlation between the Fat% and the Goutallier grade was determined. Univariate and multivariate analyses were performed to identify the independent risk factors for retear.

RESULTS

The mean preoperative Fat% of the supraspinatus muscle was 23.77 ± 15.96. A significant correlation was found between the Fat% and the Goutallier grade of the supraspinatus muscle (R = 0.655; P < .001). The overall retear rate was 21.9%; however, functional status significantly improved regardless of cuff healing. Multivariate analysis identified the Fat% (P = .005) and the modified Patte classification (P = .003) as independent risk factors of retear. The receiver operating characteristic curves showed that the cutoff value of Fat% for predicting retear was 33.2%. Fat% >33.2% possessed superior diagnostic accuracy (79.0%), Youden index (0.513), and positive and negative predictive values (51.6% and 90.5%, respectively) compared with the Goutallier grades.

CONCLUSION

Although the quantitative method for assessing Fat% of the supraspinatus muscle significantly correlated with the Goutallier classification, the quantitative method is more clinically relevant to retear. Fat% of the supraspinatus muscle >33.2% possessed higher diagnostic value than the Goutallier grades in predicting retear.

Midterm Functional Outcomes After Retear of an Arthroscopic Rotator Cuff Repair: A Propensity Score-Matched Comparative Study

BACKGROUND

Studies are still limited on the isolated effect of retear after arthroscopic rotator cuff repair (ARCR) on functional outcomes after the midterm period.

PURPOSE

To assess the effect of retear at midterm follow-up after ARCR and to identify factors associated with the need for revision surgery.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A retrospective review was conducted on patients who underwent ARCR between 2014 and 2018, with a minimum 5-year follow-up. The structural integrity was evaluated using magnetic resonance imaging. After propensity score matching, 65 patients for the retear group and 65 for the healed group were included. Functional outcomes, including visual analog scale for pain and function (PVAS and FVAS) and American Shoulder and Elbow Surgeons (ASES) score, were compared between the groups at 1 year and final follow-up. Multivariate analysis was conducted on the retear group to identify factors associated with the final ASES score.

RESULTS

The mean ± SD follow-up period was 6.9 ± 1.4 years. All outcomes at the final follow-up improved as compared with the preoperative status, regardless of retear (all P < .001). In the retear group, PVAS at the final follow-up showed deterioration when compared with postoperative 1 year (P = .044). While there were no significant differences in all outcomes at 1 year postoperatively between the groups (all P > .05), the retear group demonstrated significantly worse outcomes than the healed group in scores on the PVAS (2.5 ± 1.5 vs 1.9 ± 1.5; P = .011), FVAS (7.3 ± 1.4 vs 7.8 ± 1.3; P = .020), and ASES (73.2 ± 12.7 vs 79.9 ± 15.4; P = .008) at the final follow-up. The revision rate in the retear group was 12.8%, and multivariate analysis showed that larger anteroposterior retear size (P = .017) and retear of the subscapularis (P = .047) were negatively associated with the final ASES score.

CONCLUSION

Functional outcomes after ARCR improved during midterm follow-up, regardless of retear. While the effect of retear itself on functional outcomes was minimal in the short term, it became more pronounced after the midterm period. A retear involving the subscapularis or with a larger anteroposterior size was associated with a poorer functional outcome.

CT imaging findings in symptomatic patients with and without revision surgery after reverse shoulder arthroplasty

OBJECTIVES

To evaluate CT imaging findings in symptomatic patients with and without revision surgery (RS) after reverse shoulder arthroplasty (RSA).

MATERIALS AND METHODS

In this retrospective study, two radiologists assessed CT imaging findings in symptomatic patients with RSA over 5 years, including material fracture and loosening of the peg, baseplate, screws, and humeral stem, screw positioning, prosthesis dislocation, glenoid notching, fractures, and deltoid muscle quality. The primary outcome parameter was RS. Patients were assigned Group 1 (RS) or Group 2 (No RS).

RESULTS

Ninety-nine patients (mean age 70.4 ± 10.3 years, 61 females) met the inclusion criteria. Fifty-two patients (29 females) received RS after 34.0 ± 38.3 months. The only CT imaging finding significantly associated with RS was prosthesis dislocation (P = .007, odds ratio (OR) 10.95, 95% CI 1.34-89.24). All other evaluated CT imaging findings were not associated with RS. Yet, loosening of the peg (30% vs. 16%), baseplate (15% vs. 6%), and superior screw (18% vs. 7%) and periprosthetic humeral fractures (29% vs. 13%)-as common reasons for RS-were more frequent in patients with RS than in those without, however not reaching significance (P ≥ .11). The large majority of patients had glenoid notching (79% vs. 94%), irrespective of RS.

CONCLUSION

In this cohort of symptomatic patients after RSA, prosthesis dislocation was the only CT imaging finding associated with RS. Besides, there was a trend with higher numbers of loosening of the peg, baseplate, and superior screw, as well as periprosthetic humeral fractures in patients with RS, though not reaching significance.

Supraspinous Fossa: Anatomy and Pathology

Supraspinous fossa is an important location in the periscapular region, which houses important structures such as the supraspinatus muscle and the suprascapular nerve. The supraspinous fossa can be affected by pathologies involving its contents (supraspinatus muscle and suprascapular nerve), osseous boundary (scapular body, distal clavicle, and spinous process), or superficial soft tissue covering it. In this pictorial review, we describe the detailed anatomy of the supraspinous fossa. We have also covered imaging of wide range of pathologies that can affect supraspinous fossa such as paralabral cyst, muscle edema/atrophy, malignancies (primary and secondary), and miscellaneous lesions (myositis ossificans, fibromatosis, nerve sheath tumor, etc.). An awareness of the imaging findings of these entities is essential for a radiologist to avoid misinterpretation and can aid a timely diagnosis.

A visual marker for early atrophy of the supraspinatus muscle on conventional MRI: introduction of the blackbird sign

OBJECTIVES

The aim of this study was to introduce the blackbird sign as a fast, qualitative measure of early supraspinatus (SSP) muscle atrophy and to correlate the sign with quantitatively assessed muscle volume and intramuscular fat fraction (FF) in patients with full-thickness SSP tears.

MATERIALS AND METHODS

The blackbird sign describes the asymmetric pattern of early SSP atrophy: on sagittal MR images, the supero-posterior contour of the muscle becomes concave, resembling the shape of a blackbird. MRIs of patients with full-thickness SSP tears were retrospectively reviewed for the presence of the blackbird and tangent signs. Patients were then divided into group 1: negative tangent sign and negative blackbird sign (n = 67), group 2: negative tangent sign and positive blackbird sign (n = 31), and group 3: positive tangent sign (n = 32). A 2-point Dixon sequence was acquired in all patients from which quantitative FF and muscle volumes were calculated.

RESULTS

In total 130 patients (mean age 67 ± 11 years) were included. Mean SSP volume was significantly smaller in group 3 (15.8 ± 8.1 cm3) compared to group 2 (23.9 ± 7.0 cm3, p = 0.01) and group 1 (29.7 ± 9.1 cm3, p < 0.01). Significantly lower muscle volumes were also found in group 2 compared to group 1 (p = 0.02), confirming that the blackbird sign is able to identify early SSP atrophy. Mean FF in the SSP was significantly higher in group 3 (18.5 ± 4.4%) compared to group 2 (10.9 ± 4.7%, p < 0.01) and group 1 (6.1 ± 2.6%, p < 0.01).

CONCLUSION

Visual assessment of early muscle atrophy of the SSP is feasible and reproducible using the blackbird sign, allowing the diagnosis of early SSP atrophy.

CLINICAL RELEVANCE STATEMENT

In routine clinical practice, the blackbird sign may be a useful tool for assessing early muscle degeneration before the risk of postoperative rotator cuff re-tears increases with progressive muscle atrophy and fatty infiltration.

KEY POINTS

Quantitative measurements of rotator cuff injuries require time, limiting clinical practicality. The proposed blackbird sign is able to identify early SSP atrophy. Reader agreement for the blackbird sign was substantial, demonstrating reproducibility and ease of implementation in the clinical routine.

Superior capsular reconstruction of the shoulder with biceps autograft vs. Achilles allograft: A 2-year comparative study

PURPOSE

To retrospectively evaluate the clinical-functional outcomes, healing rates, complications, and surgical time in patients treated with superior capsular reconstruction (SCR) using long head of the biceps autograft (LHB) and Achilles allograft (AA).

MATERIALS AND METHODS

This retrospective study included 24 patients with irreparable rotator cuff tears of the supraspinatus and infraspinatus, treated with SCR. Two treatment groups were formed: one with 12 cases using AA and another with 12 cases using LHB. All patients were followed for a minimum of 2 years.

RESULTS

The SSV was 73.7±25.3 vs. 86.0±8.7 (p=0.26), the Constant score was 76.8±20.1 vs. 83.7±4.6 (p=0.12), and the VAS was 1.6±2.3 vs. 1.7±0.5 (p=0.9) for the LHB and AA groups, respectively. Tendon healing was 66.7% in AA and 100% in LHB (p=0.001). Complications were 50% in AA and 0% in LHB. The average surgical time was 127.7±37.6minutes for AA and 84.3±14.3min for LHB (p=0.01).

CONCLUSIONS

SCR with LHB showed better results in terms of tendon healing, fewer complications, and reduced surgical time compared to the use of AA.

Medial scapular body (MSB) Goutallier classification: MRI-based reliability and validity of evaluation of the Goutallier classification for grading fatty infiltration of the rotator cuff

BACKGROUND

The degree of atrophy and fatty infiltration of rotator cuff muscle belly is a key predictor for cuff repairability. Traditionally, Goutallier grading of fatty infiltration is assessed at sagittal scapular Y-view. Massive rotator cuff tears are associated with tendon retraction and medial retraction of cuff musculature, resulting in medialization of the muscle bulk. Thus, standard Y-view can misrepresent the region of interest and may misguide clinicians when assessing repairability. It is hypothesized that by assessing the muscle belly with multiple medial sagittal magnetic resonance imaging (MRI) sections at the medial scapular body, the Medial Scapular Body-Goutallier Classification (MSB-GC) will improve reliability and repeatability, giving a more representative approximation to the degree of fatty infiltration, as compared with the original Y-view.

METHODS

Fatty infiltration of the rotator cuff muscles were classified based on the Goutallier grade (0-4) at 3 defined sections: section 1, original Y-view; section 2, level of suprascapular notch; and section 3, 3 cm medial to the suprascapular notch on MRI scans. Six subspecialist fellowship-trained shoulder surgeons and 3 musculoskeletal radiologists independently evaluated deidentified MRI scans of included patients.

RESULTS

Of 80 scans, 78% (n = 62) were massive cuff tears involving the supraspinatus, infraspinatus, and subscapularis tendons. Interobserver reliability (consistency between observers) for Goutallier grade was excellent for all 3 predefined sections (range: 0.87-0.95). Intraobserver reliability (repeatability) for Goutallier grade was excellent for all 3 sections and 4 rotator cuff muscles (range: 0.83-0.97). There was a moderate to strong positive correlation of Goutallier grades between sections 1 and 3 and between sections 2 and 3 and these were statistically significant (P < .001). There was a reduction in the severity of fatty infiltration on the Goutallier classification from sections 1 to 3 across all muscles: 42.5% of both supraspinatus and infraspinatus were downgraded by 1, 20% of supraspinatus and 3.8% of infraspinatus were downgraded by 2, and 2.5% of supraspinatus were downgraded by 3.

CONCLUSION

This study found that applying the Goutallier classification to more medial MRI sections (MSB-GC) resulted in assignment of lower grades for all rotator cuff muscles. Additionally, this method demonstrated excellent test-retest reliability and repeatability. Inclusion of a more medial view or whole scapula on MRI, especially in advanced levels of tear retraction, could be more reliable and representative for assessment of the degree of fatty infiltration within the muscle bulk that could help predict tear repairability and therefore improve clinical decision making, which should be studied further in clinical studies.

Three-dimensional sectional measurement approach for serial volume changes in shoulder muscles after arthroscopic rotator cuff repair

Purpose

This study assessed the serial volume changes in multiple shoulder muscles simultaneously following arthroscopic rotator cuff repair (ARCR) by a three-dimensional (3D) modeling-based sectional measurement. These volume changes were correlated with background preoperative factors.

Methods

Four consecutive magnetic resonance imaging scans (preoperatively and postoperatively at 3, 6, and 12 months) of 33 shoulders from 31 patients who underwent arthroscopic rotator cuff repair were examined. We focused on the sectional volume differences of the supraspinatus, infraspinatus, teres minor, and subscapularis between preoperatively and 3 months postoperatively (Dif.pre.3mo) and between 3 and 12 months postoperatively (Dif.3.12mo). The correlation between volume differences and clinical/demographic parameters was determined by a multivariate analysis.

Results

No statistically significant differences were observed for most serial changes in the shoulder muscle volumes. The tear-site muscles (supraspinatus and infraspinatus) showed similar tendencies for volume changes, whereas the non-tear-site muscles (teres minor and subscapularis) differed. A negative correlation was observed between Dif.pre.3mo and Dif.3.12mo for the supraspinatus, infraspinatus, and teres minor. These perioperative volume differences might correlate with tear size and symptom duration in the supraspinatus, as well as with a history of steroid injections and work and sports activity levels in the infraspinatus and teres minor.

Conclusion

The serial volume changes in multiple shoulder muscles after ARCR measured using our 3D sectional approach exhibited different tendencies and clinical implications depending on the primary and non-primary site of tears. Our method may serve as a potential indicator to facilitate muscle recovery and prevent the progression of postoperative muscle atrophy.

Factors Associated With Supraspinatus Atrophy in Patients 50 Years and Older With Atraumatic Shoulder Pain

Background

Atrophy and fatty infiltration of the supraspinatus (SS) muscle are prognostic indicators of poor functional outcomes and higher retear rates after rotator cuff repair. While older patients, female patients, and those with massive and retracted rotator cuff tears are at a higher risk for these indicators, it is unclear whether tear characteristics, acromion morphology, and acromioclavicular (AC) joint arthritis affect SS atrophy in older patients with chronic shoulder pain.

Purpose

To investigate the multifactorial influences associated with SS atrophy in rotator cuff tears.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

A review was conducted on 391 patients with atraumatic shoulder pain (mean age, 60.88 ± 8 years; range, 50-93 years; 200 men and 191 women) who underwent magnetic resonance imaging between May 2019 and April 2020. SS atrophy was calculated using the occupation ratio. Logistic regression was performed to evaluate the association of SS atrophy with patient age and sex, rotator cuff tear type (partial- vs full-thickness), anteroposterior (AP) tear size, AC and glenohumeral (GH) joint arthritis, and acromion shape. A subgroup analysis was performed in patients without tears to investigate whether SS atrophy and fatty infiltration were independent phenomena.

Results

Overall, 91 patients had full-thickness tears without retraction, 131 had partial-thickness tears, and 169 had no tears. The prevalence of SS atrophy was associated with patient age and was more prevalent in women (67.6%), full-thickness tears (91.1%), an AP tear size of >15 mm (92.6%), and GH joint arthritis (100%) (P < .001 for all). The severity of atrophy (indicated by a decrease in the occupation ratio) increased with older age. In the patients without tears, SS atrophy prevalence was 33.1%. Logistic regression analysis showed significant independent associations of SS atrophy with age (P < .001), female sex (P < .001), nonretracted full-thickness tears (P < .001), an AP tear size of >15 mm (P < .001), and hook-shaped acromion (P = .007). A subgroup analysis of the nontear group revealed a significant association of SS atrophy with fatty infiltration (P < .001).

Conclusion

This study identified significant associations between SS atrophy and older age, female sex, full-thickness tear without retraction, an AP tear size of >15 mm, and hook-shaped acromion. Notably, partial-thickness tears were not significantly associated with SS atrophy.

Sectional measurements of shoulder muscle volume and computed tomography density in anterior shoulder instability

In patients with anterior shoulder instability (ASI), a chronic imbalance might exist between the anterior and posterior shoulder muscles (i.e., subscapular [Ssc] vs. infraspinatus and teres minor [Isp + TM]). The balance could be evaluated as the ratio of volume (VR Ssc/Isp+TM) and computed tomography density (CT-DR Ssc/Isp+TM) using a 3D sectional approach. A total of 28 CT images (19 patients) of non-pathological shoulders (clavicular fracture [CF]) and 17 CT images (17 patients) of ASI were used. Segmentation of Ssc and Isp + TM muscles was performed; the reconstructed models were separated by the Y-view plane and the planes situated 2.5 cm and 5 cm medial to the Y-view plane to generate muscle models. VR Ssc/Isp+TM and CT-DR Ssc/Isp+TM were measured in each section of both the groups, as well as in whole muscle measurements in the CF group. VR Ssc/Isp+TM and CT-DR Ssc/Isp+TM obtained through a 3D sectional approach in the CF group were comparable to the whole muscle measurements, with a value of 1.06 for both. In the ASI group, the VR Ssc/Isp+TM was higher, whereas the CT-DR Ssc/Isp+TM was lower than those in the CF group. The VR Ssc/Isp+TM and CT-DR Ssc/Isp+TM appeared to be balanced in the CF group. However an imbalance was observed in the ASI group. Our 3D sectional measurement approach has the potential to assess the balance between the anterior and posterior shoulder muscles in ASI.

Determining the Patient Acceptable Symptom State (PASS) for Shoulder Strength After Subscapularis Arthroscopic Repair and Evaluating the Preoperative Predictors for PASS Achievement

Background

Restoring shoulder strength after arthroscopic rotator cuff repair (ARCR) is critical, but there is limited understanding as to what patients consider satisfactory postoperative strength.

Purpose

To determine the Patient Acceptable Symptom State (PASS) values for the Constant score strength parameter and internal rotation (IR) strength in patients who underwent ARCR for rotator cuff tears involving the subscapularis (SSC) muscle and evaluate for associations between preoperative and intraoperative patient characteristics with PASS achievement.

Study Design

Case-control study; Level of evidence, 3.

Methods

A retrospective analysis was conducted on prospectively collected data for 278 patients with an SSC tear (isolated or combined) who underwent ARCR and had minimum 2-year follow-up data. Functional outcomes (patient-reported outcomes, range of motion, Constant strength, and IR strength) were assessed preoperatively and at the latest follow-up. The overall, male, and female PASS values for postoperative strength measures were evaluated using receiver operating characteristic analysis. Correlation and logistic regression analyses were used to evaluate the relationship between preoperative variables and PASS achievement for Constant and IR strengths.

Results

The mean follow-up time was 72.8 months. The overall, male, and female PASS values were 9.9 lb (4.5 kg), 14.5 lb (6.6 kg), and 8.5 lb (3.9 kg), respectively, for Constant strength and 15.2 lb (6.9 kg), 20.7 lb (9.4 kg), and 12.1 lb (5.5 kg), respectively, for IR strength. Older age, high fatty infiltration of the SSC tendon (Goutallier grades 3 and 4), and failure of SSC healing correlated negatively with PASS attainment for the strength measures. High fatty infiltration of the supraspinatus and infraspinatus muscles correlated negatively with Constant strength. Decreased coracohumeral distance (CHD) and larger SSC tears correlated negatively with achieving PASS for IR strength. Workers' compensation, high supraspinatus and SSC fatty infiltration, and the use of knotted suture anchors were predictors of not achieving the overall Constant strength PASS, while lower SSC fatty infiltration and high CHD were predictors of achieving the overall IR strength PASS.

Conclusion

This study established the PASS values for Constant and IR strengths for patients after ARCR involving the SSC tendon. Workers' compensation, high supraspinatus and SSC fatty infiltration, and the use of knotted suture anchors were predictors of not achieving the overall Constant strength PASS, while lower SSC fatty infiltration and high CHD were predictors of achieving the overall IR strength PASS.

The Suprascapular Artery as a Reference for the Evaluation of Supraspinatus Fatty Infiltration on Magnetic Resonance Imaging

Background

Fatty infiltration (FI) of the supraspinatus is commonly seen in chronic large-to-massive rotator cuff tears. Evaluating FI in patients with severe muscle atrophy can be confusing.

Purpose/Hypothesis

The purpose of this study was to investigate the anatomic relationship between the suprascapular artery and supraspinatus muscle on magnetic resonance imaging (MRI) to provide a method for defining the border of the supraspinatus muscle on Y-view MRI. It was hypothesized that the branches of the suprascapular artery would encircle the supraspinatus muscle on Y-view and adjacent MRI slices and could be used for defining the supraspinatus outline on oblique sagittal images.

Study Design

Cohort study (diagnosis); Level of evidence, 3.

Methods

A total of 172 shoulders that had undergone arthroscopic repair for large-to-massive rotator cuff tears were retrospectively included. Two methods, one based on the supraspinous fossa and trapezius (SF method) and the other based on the region bounded by the branches of the suprascapular artery (SA method), were used for defining the supraspinatus outline on Y-view MRI for the assessment of FI. Preoperative supraspinatus FI grade and tangent sign and postoperative tendon integrity were evaluated. Shoulder function was assessed using the American Shoulder and Elbow Surgeons (ASES) score and active range of motion.

Results

The branches of the suprascapular artery encircled the supraspinatus in all shoulders, with the diameter of the branches ranging from 0.5 to 3 mm. The agreement in supraspinatus FI grading between the SF and SA methods was 65.12%. When limited to the 61 shoulders with a positive tangent sign, the agreement dropped to 22.95% (κ = 0.032). The group (FI grade 2 by SA method and ≥3 by SF method) showed no significant difference in postoperative outcomes compared with the 2-vs-2 group but had significantly better postoperative ASES scores (P = .001) and active range of motion in forward elevation (P = .020) compared with the ≥3-vs-≥3 group. The tangent sign was positive in 92.16% of the 2-vs-≥3 group.

Conclusion

The suprascapular artery is a reliable reference for the evaluation of supraspinatus FI. When a positive tangent sign presents, supraspinatus FI is likely to be overestimated if the hyperintensity outside the region bounded by the branches of the suprascapular artery is mistaken as FI.

Editorial Commentary: Magnetic Resonance Imaging Reveals Rotator Cuff Tear Size, Retraction, Length, and Geometry; Muscle Volume and Degeneration; and Tendon Quality

Magnetic resonance imaging (MRI) of the shoulder is commonly used for evaluating muscle bulk and fatty degeneration, as well as tendon tear size, geometry, retraction, and length. However, MRI can also be used to evaluate tendon quality. Increased rotator cuff tendon signal on T2-weighted fat-suppressed MRI appears to be a marker of tendon degeneration and potentially of impaired healing potential. Tendon signal intensity merits closer attention and may be especially relevant when selecting chronic degenerative tears for repair in patients with other risk factors for nonhealing.

Evaluation of the metabolic activity of the torn rotator cuff muscles by 18 F-2-deoxy- d -glucose PET-computed tomography scan

OBJECTIVES

Fatty atrophy and fatty infiltration have been considered as limiting factors for rotator cuff repair. The metabolic activity of the muscle can be measured noninvasively by PET. In our study, we aim to compare the metabolic activity between the shoulders with rotator cuff tears and normal shoulders.

METHODS

All the patients with unilateral full-thickness rotator cuff tears were included. The patients were divided into two groups based on fatty atrophy and the metabolic activities of the rotator cuff muscles, trapezius, and deltoid were calculated using an 18 F-2-deoxy- d -glucose PET-computed tomography scan for comparison.

RESULTS

A total of 17 patients were included. The standardized uptake values were compared between the affected shoulder and the normal shoulders. There was a significant increase in uptake in the insertion sites and musculotendinous junctions in the rotator cuff torn group. The standardized uptake values showed no significant difference between the low-grade and high-grade groups.

CONCLUSION

Our first hypothesis was also proven wrong; when we found that there was no statistically significant difference in the metabolic activity in muscle bellies of normal shoulders and those with rotator cuff tears. Our second hypothesis was proven wrong when found that there was no statistically significant difference in the metabolic activities of rotator cuff muscles between high-grade and low-grade fatty atrophy groups. The metabolic activities of the middle deltoid and trapezius are inversely related. Based on the findings of our study, fatty atrophy or fatty infiltration alone cannot be considered a limiting factor for rotator cuff repair.

Development of a deep learning-based fully automated segmentation of rotator cuff muscles from clinical MR scans

BACKGROUND

The fatty infiltration and atrophy in the muscle after a rotator cuff (RC) tear are important in surgical decision-making and are linked to poor clinical outcomes after rotator cuff repair. An accurate and reliable quantitative method should be developed to assess the entire RC muscles.

PURPOSE

To develop a fully automated approach based on a deep neural network to segment RC muscles from clinical magnetic resonance imaging (MRI) scans.

MATERIAL AND METHODS

In total, 94 shoulder MRI scans (mean age = 62.3 years) were utilized for the training and internal validation datasets, while an additional 20 MRI scans (mean age = 62.6 years) were collected from another institution for external validation. An orthopedic surgeon and a radiologist manually segmented muscles and bones as reference masks. Segmentation performance was evaluated using the Dice score, sensitivities, precision, and percent difference in muscle volume (%). In addition, the segmentation performance was assessed based on sex, age, and the presence of a RC tendon tear.

RESULTS

The average Dice score, sensitivities, precision, and percentage difference in muscle volume of the developed algorithm were 0.920, 0.933, 0.912, and 4.58%, respectively, in external validation. There was no difference in the prediction of shoulder muscles, with the exception of teres minor, where significant prediction errors were observed (0.831, 0.854, 0.835, and 10.88%, respectively). The segmentation performance of the algorithm was generally unaffected by age, sex, and the presence of RC tears.

CONCLUSION

We developed a fully automated deep neural network for RC muscle and bone segmentation with excellent performance from clinical MRI scans.

The Subscapularis Healing Index: A New Scoring System for Predicting Subscapularis Healing After Arthroscopic Repair

BACKGROUND

Previous research has emphasized the effect of prognostic factors on arthroscopic rotator cuff repair (ARCR) success, but a specific focus on subscapularis (SSC) tendon repair healing is lacking.

PURPOSE

To identify prognostic factors for SSC healing after ARCR and develop the Subscapularis Healing Index (SSC-HI) by incorporating these factors.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

This was a retrospective study using prospectively maintained data collected from patients with isolated or combined SSC tears who underwent ARCR between 2011 and 2021 at a single institution with a minimum 2-year follow-up. Functional outcomes were assessed using the American Shoulder and Elbow Surgeons (ASES) score, Subjective Shoulder Value (SSV), and visual analog scale (VAS) pain scale. SSC tendon healing was evaluated via ultrasound at the final follow-up. Multivariate logistic regression analysis was performed to determine the factors affecting SSC healing, and based on these factors, the SSC-HI, which ranges from 0 to 15 points, was developed using odds ratios (ORs).

RESULTS

Among 1018 ARCR patients, 931 met the inclusion criteria; 279 returned voluntarily for postoperative SSC ultrasound assessment. The overall healing failure rate was 10.8% (30/279). Risk factors for healing failure included female sex (P = .008; OR, 3.119), body mass index (BMI) ≥30 (P = .053; OR, 2.323), supraspinatus fatty infiltration ≥3 (P = .033; OR, 3.211), lower SSC fatty infiltration ≥2 (P = .037; OR, 3.608), and Lafosse classification ≥3 (P = .007; OR, 3.224). A 15-point scoring system comprised the following: 3 points for female sex, 2 points for BMI ≥30, 3 points for supraspinatus fatty infiltration ≥3, 4 points for lower SSC fatty infiltration ≥2, and 3 points for Lafosse classification ≥3. Patients with ≤4 points had a 4% healing failure rate, while those with ≥9 points had a 55% rate of healing failure. Patients with a healed SSC reported significantly higher ASES (healed SSC: ΔASES, 44.7; unhealed SSC: ΔASES, 29; P < .01) and SSV (healed SSC: ΔSSV, 52.9; unhealed SSC: ΔSSV, 27.5; P < .01) and lower VAS (healed SSC: ΔVAS, -4.2; unhealed SSC: ΔVAS, -3; P < .01) scores compared with those with an unhealed SSC.

CONCLUSION

The SSC-HI scoring system integrates clinical and radiological factors to predict SSC healing after surgical repair. Successful SSC healing was found to be associated with enhanced functional outcomes, underscoring the clinical relevance of SSC healing prediction in the management of these tears.

3D quantitative CT study to assess rotator cuff muscle fatty infiltration

Fatty infiltration is a degenerative condition of the tendon-muscle unit of rotator cuff muscles, characterized by fatty accumulation within and around the muscles. This study compares a 3D method to the Goutallier classification for evaluating fatty infiltration of the rotator cuff muscles. Employing a retrospective study design, four researchers performed 3D segmentation of the rotator cuff muscles on 65 CT scans of patients with rotator cuff arthropathy. The Goutallier classification was graded on screenshots of the Y view and two axial slices. Measurements, including HU, volume, cross-sectional area, and Goutallier grade, were performed on the 3D segmentations and the respective 2D slices. The inter- and intra-rater variability for 2D and 3D methods were calculated using the Intraclass Correlation Coefficient (ICC). The ICC for 2D and 3D methods was excellent (ICC: 0.90-0.95 and 0.81-0.99, respectively) and good for the Goutallier classification (ICC: 0.62-0.81). Overall, the relative 3D fatty infiltration was 0% for Goutallier grade 0 muscles, 7% for grade 1, 19% for grade 2, 33% for grade 3, and 37% for grade 4. The relative 2D fatty infiltration was 0%, 8%, 25%, 37%, and 43%, respectively. We conclude that 3D segmentation on CT scans is better reproducible and evaluates the muscle entirely. However, the time-intensive nature of the 3D method currently limits its clinical practicality. Quantitive 2D evaluation is excellently reproducible but may overestimate the actual fatty infiltration percentage of the whole muscle.

Factors associated with long head of the biceps tendon tear severity and predictive insights for grade II tears in rotator cuff surgery

BACKGROUND

In rotator cuff repair, the long head of the biceps tendon (LHB) is commonly used as graft material. However, factors influencing LHB tear severity are poorly understood, and predicting grade II LHB tears is challenging. This study aimed to identify these factors preoperatively.

METHODS

The demographics, medical parameters, and pain severity of 750 patients who underwent arthroscopic surgery from January 2010 to February 2021 were evaluated to determine the factors associated with LHB tear severity and grade II tears. Both overall and largeto-massive rotator cuff tear (RCT) cohorts underwent ordinal and binary logistic regression analyses. Predictive accuracy for grade II LHB tears was determined using the area under the receiver operating characteristic curve (AUC).

RESULTS

In the overall cohort, high-sensitivity C-reactive protein (hs-CRP) >1 mg/L (P<0.001), subscapularis tear (P<0.001), hypothyroidism (P=0.031), and the tangent sign (P=0.003) were significantly associated with LHB tear severity, and hs-CRP>1 mg/L, subscapularis tear, and Patte retraction degree were significantly associated with grade II LHB tears (P<0.001). In the large-to-massive RCT cohort, hs-CRP>1 mg/L, hypertension, and age ≥50 years (P<0.05) were significantly associated with LHB tear severity, and hs-CRP>1 mg/L (P<0.001) and hypertension (P=0.026) were significantly associated with grade II LHB tears. In both cohorts, hs-CRP >1 mg/L demonstrated good predictive accuracy for grade II LHB tears (AUCs: 0.72 and 0.70).

CONCLUSIONS

Serum hs-CRP >1 mg/L is associated with LHB tear severity and serves as a reliable predictor of grade II LHB tears, facilitating preoperative assessment of the LHB as potential graft material in arthroscopic rotator cuff repair. Level of evidence: III.

Leukocyte-Poor Platelet-Rich Plasma as an Adjuvant to Arthroscopic Rotator Cuff Repair Reduces the Retear Rate But Does Not Improve Functional Outcomes: A Double-Blind Randomized Controlled Trial

BACKGROUND

Whether the use of PRP as an adjuvant of rotator cuff repairs leads to improved tendon healing and better functional outcomes remains unclear in clinical evidence.

PURPOSE

The main purpose of this study was to assess whether the use of leukocyte-poor platelet-rich plasma (LP-PRP) as an adjuvant to arthroscopic rotator cuff repair (ARCR) decreases the rate of retears compared with a control group. The secondary objective was to analyze whether LP-PRP improves patient-reported outcomes.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

This was a double-blind randomized controlled trial at a single center. A consecutive series of 96 patients with rotator cuff tears <3 cm were enrolled and randomly allocated to the control group (double-row suture-bridge ARCR alone [n = 48]) and the PRP group (double-row suture-bridge repair, followed by 1 LP-PRP injection during surgery [n = 48]). The visual analog scale (VAS) for pain, the American Shoulder and Elbow Surgeons (ASES) score, the Single Assessment Numeric Evaluation (SANE), and the Pittsburgh Sleep Quality Index (PSQI) were administered preoperatively and at 6- and 12-month follow-up. Magnetic resonance imaging (MRI) was performed to evaluate tendon integrity at 6-month follow-up. Both patients and assessors were blinded to the intervention received during surgery.

RESULTS

The mean patient age was 56.1 ± 2.98 years. Of the 96 patients, 90 had MRI performed at 6 months after surgery (94% radiological follow-up). The retear rate in the PRP group was 15.2% (7/46 [95% CI, 6%-28%]), which was lower than that in the control group of 34.1% (15/44 [95% CI, 20%-49%]) (P = .037). Therefore, the risk ratio of ruptures in patients exposed to LP-PRP was 0.44 (95% CI, 0.2-0.9; P = .037). Overall, the ASES, VAS, SANE, and PSQI scores showed a statistical improvement after surgery (P < .001). There were no significant differences in functional scores between the groups. Most of the patients exceeded the minimal clinically important difference for the ASES, SANE, and VAS without significant differences between the groups.

CONCLUSION

In patients with rotator cuff tears <3 cm undergoing double-row suture-bridge repair, a 5-mL dose of LP-PRP injected at the tendon-bone interface significantly reduced the retear rate. However, the use of LP-PRP in terms of postoperative pain and patient-reported outcomes failed to show clinically meaningful effects.

REGISTRATION

NCT04703998 (ClinicalTrials.gov identifier).

Higher Upper Subscapularis Goutallier Grade and Coracohumeral Distance Narrowing Are Predictive of Subscapularis Tears in Patients Undergoing Arthroscopic Rotator Cuff Repair

PURPOSE

To evaluate the relation between subscapularis (SSC) Goutallier grade or coracohumeral distance (CHD) and SSC tears, as well as the relation between these radiographic variables and long head of the biceps tendon lesions.

METHODS

A retrospective analysis was conducted on prospectively maintained data on patients who underwent arthroscopic rotator cuff repair of SSC tears between 2011 and 2021 with at least 6 months of follow-up. Patients with identified subscapularis tears during arthroscopy were included. A control group was established by randomly selecting patients without SSC tears from the same study period. Goutallier grading and CHD were obtained from preoperative magnetic resonance imaging (MRI) scans. Receiver operating characteristic analysis was conducted to define optimal cutoff values for these diagnostic measures.

RESULTS

The study included 735 patients with SSC tears and 249 patients in the control group. Comparing subscapularis tear and intact groups' Goutallier grades revealed significant differences in infraspinatus, upper and lower SSC, and overall SSC (P < .001). No significant difference was detected in supraspinatus Goutallier grade (P = .364). An SSC tear was observed in 58.3% (n = 265) of patients with Goutallier grade 0 of the upper SSC, 77.1% (n = 195) of patients with grade 1 changes, 98.7% (n = 155) with grade 2 changes, and 100% of grade 3 or 4 changes. Goutallier grade of the upper SSC showed a significant correlation with tear size (rs = 0.533; P < .01). CHD measurements were lower in individuals with SSC tears compared to those without tears (6.6 ± 1.7 vs 9.6 ± 1.8; P < .001). Upper SSC Goutallier grade >1 had an acceptable area under the curve (AUC) of 0.742. CHD of 7.96 mm or less had an excellent predictive AUC of 0.879.

CONCLUSIONS

Higher Goutallier grade and CHD narrowing are potential associations predictive of SSC tears. Routine MRI assessment of muscle of the upper SSC and the CHD can contribute to the diagnostic accuracy of SSC tears and offer valuable information regarding the severity of such tears.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Determining minimal clinically important difference and patient-acceptable symptom state after arthroscopic isolated subscapularis repair

Background

Minimal Clinically Important Difference (MCID) and Patient-Acceptable Symptomatic State (PASS) have emerged as patient-based treatment assessments. However, these have not been investigated in patients undergoing arthroscopic isolated subscapularis repair (AISR). The primary purpose of this study was to determine the MCID and PASS for commonly used patient-reported outcomes in individuals who underwent AISR. The secondary purpose was to assess potential associations between preoperative and intraoperative patient characteristics and the MCID and PASS.

Methods

A retrospective analysis was conducted on prospectively collected data for patients who underwent primary AISR between 2011 and 2021 at a single institution, with minimum 2-year postoperative follow-up. Functional outcomes were assessed using the American Shoulder and Elbow Surgeons (ASES) score, Subjective Shoulder Value (SSV), and Visual Analog Scale (VAS) pain scale. The MCID was determined using the distribution-based method, while PASS was evaluated using area under the curve analysis. To investigate the relationship between preoperative variables and the achievement of MCID and PASS thresholds, Pearson and Spearman coefficient analyses were employed for continuous and noncontinuous variables, respectively.

Results

A total of 77 patients with a mean follow-up of 58.1 months were included in the study. The calculated MCID values for VAS pain, ASES, and SSV were 1.2, 10.2, and 13.2, respectively. The PASS values for VAS pain, ASES, and SSV were 2.1, 68.8, and 68, respectively. There was no significant correlation between tear characteristics and the likelihood of achieving a MCID or PASS. Female sex, worker's compensation status, baseline VAS pain score, and baseline ASES score, exhibited weak negative correlations for achieving PASS for VAS pain and ASES.

Conclusion

This study defined the MCID and PASS values for commonly used outcome measures at short-term follow-up in patients undergoing AISR. Tear characteristics do not appear to impact the ability to achieve a MCID or PASS after AISR. Female sex, worker's compensation claim, and low baseline functional scores have weak negative correlations with the achievement of PASS for VAS pain and ASES scores.

Intrasynovial autograft for reconstruction of chronic large rotator cuff tears in a rabbit model: biomechanical, computed tomography, and histological results

BACKGROUND

Rotator cuff (RC) tears are a common cause of shoulder dysfunction and pain, posing significant challenges for orthopedic surgeons. Grafts have been proposed as a solution to augment or bridge torn tendons, but optimal clinical outcomes are not always achieved due to poor graft integration, suboptimal mechanical properties, and immunological reactions. The aim of this study was to investigate the biomechanical, CT and histological results of RC reconstruction using an intrasynovial tendon autograft, in a chronic large tear subscapularis rabbit model.

METHODS

Twenty-six adult male Zealand white rabbits were used in this study. Large defects in the subscapularis tendons were produced bilaterally in 20 rabbits. After 6 weeks, secondary procedures were performed to the right shoulder of the rabbits, which were reconstructed with an intrasynovial interposition autograft (graft group). The left shoulder did not undergo any further treatment (defect group). The specimens were randomly divided into two equal time groups and underwent biomechanical testing, CT analysis, and histological evaluation at 6, and 12 weeks after reconstruction. In addition, 6 rabbits that were not operated, were used as a control group.

RESULTS

At 12 weeks post-repair, the graft group exhibited a significant increase in ultimate failure load compared to the defect group (p < 0.05). Furthermore, the 12-week graft group demonstrated comparable stiffness to that of the control group. CT analysis indicated no significant progression of intramuscular fat accumulation in both graft groups, in contrast to the 12-week defect group when compared to the control group. Finally, histological evaluation revealed a gradual integration of the graft with the host tissue at 12 weeks.

CONCLUSION

Our study suggests that intrasynovial flexor tendon autografts hold promise as an effective interposition graft for the reconstruction of chronic large RC tears, as they improve the biomechanical and biological properties of the repaired tendon. Nonetheless, further investigations in preclinical large animal models are warranted to validate and extrapolate these findings to human studies.

Mid- to long-term outcomes of latissimus dorsi tendon transfer for massive irreparable posterosuperior rotator cuff tears: a systematic review and meta-analysis

BACKGROUND

This study aims to analyze the mid-to long-term results of the latissimus dorsi tendon for the treatment of massive posterosuperior irreparable rotator cuff tears as reported in high-quality publications and to determine its efficacy and safety.

METHODS

A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed, Scopus, and EMBASE databases were searched until December 2022 to identify studies with a minimum 4 year follow-up. Clinical and radiographic outcomes, complications, and revision surgery data were collected. The publications included were analyzed quantitatively using the DerSimonian Laird random-effects model to estimate the change in outcomes from the preoperative to the postoperative condition. The proportion of complications and revisions were pooled using the Freeman-Tukey double arcsine transformation.

RESULTS

Of the 618 publications identified through database search, 11 articles were considered eligible. A total of 421 patients (432 shoulders) were included in this analysis. Their mean age was 59.5 ± 4 years. Of these, 277 patients had mid-term follow-up (4-9 years), and 144 had long-term follow-up (more than 9 years). Postoperative improvements were considered significant for the following outcome parameters: Constant-Murley Score (0-100 scale), with a mean difference (MD) = 28 points (95% confidence interval [CI] 21, 36; I2 = 89%; P < .001); visual analog scale, with a standardized MD = 2.5 (95% CI 1.7, 3.3; P < .001; I2 = 89%; P < .001); forward flexion, with a MD = 43° (95% CI 21°, 65°; I2 = 95% P < .001); abduction, with a MD = 38° (95% CI 20°, 56°; I2 = 85%; P < .01), and external rotation, with a MD = 8° (95% CI 1°, 16°; I2 = 87%; P = .005). The overall reported mean complication rate was 13% (95% CI 9%, 19%; I2 = 0%), while the reported mean revision rate was 6% (95% CI: 3%, 9%; I2 = 0%).

CONCLUSIONS

Our pooled estimated results seem to indicate that latissimus dorsi tendon transfer significantly improves patient-reported outcomes, pain relief, range of motion, and strength, with modest rates of complications and revision surgery at mid-to long-term follow-up. In well-selected patients, latissimus dorsi tendon transfer may provide favorable outcomes for irreparable posterosuperior cuff tears.

Lower Trapezius Transfer Improves Clinical Outcomes With a Rate of Complications and Reoperations Comparable to Other Surgical Alternatives in Patients with Functionally Irreparable Rotator Cuff Tears: A Systematic Review

PURPOSE

To analyze the clinical outcomes of lower trapezius transfer (LTT) for patients with functionally irreparable rotator cuff tears (FIRCT) and summarize the available literature regarding complications and reoperations.

METHODS

After registration in the International prospective register of systematic reviews (PROSPERO [CRD42022359277]), a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was performed. Inclusion criteria were English, full-length, peer-reviewed publications with a level of evidence IV or higher reporting on clinical outcomes of LTT for FIRCT. Ovid MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus via Elsevier databases were searched. Clinical data, complications and revisions were systematically recorded.

RESULTS

Seven studies with 159 patients were identified. The mean age range was 52 to 63 years, 70.4% of the patients included were male, and the mean follow-up time ranged between 14 and 47 months. At final follow-up, LTT lead to improvements in range of motion, with reported forward elevation (FE) and external rotation (ER) mean gains of 10° to 66° and 11° to 63°, respectively. ER lag was present before surgery in 78 patients and was reversed after LTT in all shoulders. Patient-reported outcomes were improved at final follow-up, including the American Shoulder and Elbow Society score, Shoulder Subjective Value and Visual Analogue Scale. The overall complication rate was 17.6%, and the most reported complication was posterior harvest site seroma/hematoma (6.3%). The most common reoperation was conversion to reverse shoulder arthroplasty (5%) with an overall reoperation rate of 7.5%.

CONCLUSIONS

Lower trapezius transfer improves clinical outcomes in patients with irreparable rotator cuff tears with a rate of complications and reoperations comparable to other surgical alternatives in this group of patients. Increases in forward flexion and ER are to be expected, as well as a reversal of ER lag sign when present before surgery.

LEVEL OF EVIDENCE

Level IV, systematic review of Level III-IV studies.

Clinical and radiographic long-term outcomes of hemiarthroplasty for complex proximal humeral fractures

BACKGROUND

Hemiarthroplasty (HA) is a treatment option for complex proximal humeral fractures not suitable for conservative treatment or open reduction-internal fixation. Long-term outcomes using a large-metaphyseal volume prosthesis in the management of proximal humeral fractures have not been reported thus far.

METHODS

Between 2006 and 2010, 41 patients with proximal humeral fractures were treated with HA at our institution (average age, 62 years; age range, 38-85 years). Nine patients underwent revision surgery, 3 were lost to follow-up, and 7 died unrelated to the index surgical procedure. Twenty-two patients were reviewed clinically and radiographically after a mean period of 10.4 years (range, 9-13 years).

RESULTS

Of the 9 HA failures, 7 occurred within the first 2 postoperative years: 2 patients had infections and 5 had greater tuberosity nonunions or malunions. The other 2 patients underwent revision for rotator cuff deficiency >5 years after initial surgery. Among the patients available for final follow-up, the implant survival rate was 71% (22 of 31 patients). At final follow-up, these patients showed a mean relative Constant score of 76% (range, 49%-96%), mean active elevation of 116° (range, 60°-170°), and mean external rotation of 28° (range, 0°-55°). The majority had good or excellent internal rotation, with internal rotation to the 12th thoracic vertebra in 13 patients (59%) and to the eighth thoracic vertebra in 7 (31%). The mean Subjective Shoulder Value was 76% (range, 40%-100%). Clinical outcomes did not significantly deteriorate over a period of 10 years, except for flexion (P < .001) and internal rotation (P = .002). On analysis of greater tuberosity healing, 1 patient had a nonunion and 10 patients (45%) had a malunion, whereas the greater tuberosity had healed in an anatomic position in 12 patients (55%). Patients with a displaced malunion of the greater tuberosity did not have inferior clinical results at last follow-up. Only 2 patients showed glenoid erosion, and in no patients could stem loosening be identified at final follow-up.

CONCLUSION

The revision rate following large-metaphyseal volume HA to treat a proximal humeral fracture was 29% after 10 years postoperatively, with failure within 2 years largely related to greater tuberosity nonunion or malunion and failure later related to rotator cuff insufficiency. Patients with a retained implant showed good clinical and radiographic long-term results, without relevant deterioration over time even when the greater tuberosity healed in a nonanatomic position.

Longitudinal Changes in Overall 3D Supraspinatus Muscle Volume and Intramuscular Fatty Infiltration After Arthroscopic Rotator Cuff Repair

BACKGROUND

There is considerable debate regarding the longitudinal changes in overall rotator cuff (RC) muscle atrophy and intramuscular fatty infiltration (FI) following RC repair. We analyzed the longitudinal changes in overall 3D supraspinatus muscle volume and intramuscular FI (3D FI) to determine the effect of tear size and repair integrity on 3D muscle volume and intramuscular FI.

METHODS

Forty-seven patients who underwent arthroscopic RC repair and had 6-point Dixon shoulder magnetic resonance imaging (MRI) preoperatively and 3 and 12 months postoperatively were enrolled. The 3D supraspinatus muscle volume and intramuscular FI were calculated at the 3 time points, and their changes over time were evaluated in the entire cohort as well as according to tear size and repair integrity. The agreement of the difference between time points among the patients was assessed by Bland-Altman analysis.

RESULTS

In the cohort as a whole, there were no significant longitudinal changes in the 3D supraspinatus volume (19.65 ± 7.26 to 19.48 ± 7.46 cm 3 , p = 0.911) or 3D FI (17.18% ± 8.85% to 17.30% ± 9.18%, p = 0.977) from preoperatively to the final 12-month time point, overall and in the tear size and repair integrity subgroups. The 3D supraspinatus volume was significantly decreased at 3 months (17.39 ± 6.12 cm 3 , p < 0.001) but then increased again by 12 months (p < 0.001), reaching a value similar to the preoperative level. The 3D FI had a small increase at 3 months (18.18% ± 9.65%, p = 0.097) but subsequently decreased slightly again (p = 0.211), such that there were no significant longitudinal changes. The differences in the 3D supraspinatus volume and FI between these time points showed high agreement among patients.

CONCLUSIONS

The overall 3D supraspinatus volume and 3D FI showed no longitudinal change between the preoperative baseline and the 12-month follow-up after arthroscopic RC repair. Tear size and repair integrity had no impact on the longitudinal patterns of muscle volume and intramuscular FI changes. The 3D supraspinatus volume decreased during the first 3 months but recovered to baseline at 12 months postoperatively; 3D FI was relatively stable throughout the 12 months of follow-up after repair.

LEVEL OF EVIDENCE

Therapeutic Level II . See Instructions for Authors for a complete description of levels of evidence.

Clinical Outcomes and Tendon Healing After Arthroscopic Isolated Subscapularis Tendon Repair: Results at Midterm Follow-up

Background

Few studies have reported clinical outcomes and tendon healing rates after arthroscopic isolated subscapularis (SSC) repair (AISR).

Purpose/Hypothesis

The primary purpose of this study was to evaluate clinical outcomes and tendon healing after AISR. It was hypothesized that AISR would result in satisfactory clinical outcomes along with a high rate of tendon healing at the midterm follow-up. The secondary purpose was to assess the influence of tear size and muscle atrophy on SSC tendon healing and patient-reported outcomes. It was hypothesized that both would be negatively correlated with healing but would have no effect on clinical outcomes .

Study Design

Case series; Level of evidence, 4.

Methods

A retrospective analysis was conducted on prospectively collected data for 77 patients who underwent primary AISR between 2011 and 2021 at a single institution, with a minimum 2-year postoperative follow-up for all patients. Functional outcomes were assessed using the American Shoulder and Elbow Surgeons (ASES) score, the Subjective Shoulder Value (SSV), and the visual analog scale for pain. Repair techniques and concomitant procedures were also collected. SSC tendon healing was evaluated via ultrasound at the final follow-up. Linear regression analysis was performed to determine factors affecting SSC healing.

Results

The mean follow-up was 58.1 ± 3.3 months. ASES scores significantly improved from 41.5 to 81.6, and the SSV improved from 38.2 to 80.5 (P < .01 for both). Among the 40 patients (51.9%) who underwent postoperative ultrasound, 87.5% showed complete tendon healing. There were no significant differences in outcome scores between healed and unhealed tendons. Increased muscle atrophy and larger tears were correlated with failure of SSC healing (β = -0.285 [P = .015] and β = -0.157 [P = .045], respectively).

Conclusion

Improved clinical outcomes and an overall high rate of tendon healing were seen at the midterm follow-up after AISR. Smaller tear sizes with less muscle atrophy were correlated with improved tendon healing. However, even when the tendon incompletely healed, the procedure improved functional outcomes.

Cross-sectional areas of rotator cuff muscles in males without tears on shoulder MRI

OBJECTIVE

To establish reference values of rotator cuff (RC) cross sectional area (CSA) in males.

MATERIALS AND METHODS

We retrospectively analyzed shoulder MRIs from 500 patients aged 13-78 years, grouped as follows (N=100 in each): <20, 20-30, 30-40, 40-50, >50 years. All examinations were reviewed to exclude prior surgery, tears, or significant RC pathology. We segmented a standardized T1 sagittal MR image in each case to obtain CSA of supraspinatus (SUP), infraspinatus/teres minor (INF), and subscapularis (SUB) muscles. Across age groups, we recorded individual and total muscle CSA. We also performed ratios between individual muscle CSA and total CSA to examine total muscle mass contribution over age groups. We tested for differences between age groups controlled for BMI.

RESULTS

CSAs for SUP, INF, SUB, and total RC CSA were lower in subjects >50 years compared to all other groups (P<0.003 for all comparisons), persisting after controlling for BMI (P<0.03). Relative contribution of SUP CSA to total RC CSA was stable across age groups (P>0.32). INF CSA relative to total RC CSA increased with age, whereas SUB decreased (P<0.005). Subjects >50 years showed lower SUP (-15%), INF (-6%), and SUB (-21%) CSA, when compared to mean CSAs of all subjects <50 years. Total RC CSA significantly correlated with age (r=-0.34, P<0.001), persisting after controlling for BMI (r=-0.42, P<0.001).

CONCLUSION

RC muscles in male subjects with no tears on MRI show decreasing CSA with age, independent of BMI.

Serial Changes of Fatty Degeneration and Clinical Outcomes after Repair of Medium-Sized Rotator Cuff Tears

Background

This study was designed to longitudinally analyze quantitative intramuscular and perimuscular fat and evaluate clinical outcomes according to healing degree after rotator cuff repair.

Methods

From June 2013 through October 2018, patients who had undergone repair due to medium-sized rotator cuff tears and serial chest computed tomography (CT) preoperatively and at early (6-12 months) and late (at least 3 years) postoperative follow-ups were included. Supraspinatus (SST) intramuscular fat fraction ratio (IFFR) and perimuscular fat fraction ratio (PFFR) were calculated using chest CT. The rotator cuff integrity was categorized as healed, smaller retear (SRT), and larger retear (LRT) by comparing the preoperative tear size and retear size in shoulder CT arthrography at postoperative follow-ups. Clinical outcomes were evaluated using the American Shoulder and Elbow Surgeons (ASES) score, the University of California at Los Angeles (UCLA) shoulder rating scale, and the Constant score preoperatively and at early and late postoperative follow-ups.

Results

In the LRT group, compared with the preoperative values, there were increases in the SST IFFR and PFFR at the early (p = 0.002 and p = 0.006, respectively) and late (p < 0.001 and p < 0.001, respectively) postoperative time points. Late postoperative clinical scores (UCLA and Constant scores) were not improved compared to preoperative scores (p = 0.156 and p = 0.094, respectively). In the SRT group, there was no difference in the mean SST IFFR and PFFR between preoperative and early postoperative time points (p = 0.766 and p = 0.180, respectively), but the late postoperative values were higher than preoperative values (p = 0.009 and p = 0.049, respectively). Late postoperative clinical scores (ASES, UCLA, and Constant scores) in the SRT group improved compared to preoperative time (p < 0.001, p < 0.001, and p = 0.016, respectively). In the healed group, compared with the preoperative values, there was no difference in the mean SST IFFR and PFFR at postoperative time points; however, the late postoperative clinical scores (ASES, UCLA, and Constant scores) were improved (all p < 0.001).

Conclusions

In the SRT group, IFFR and PFFR progressed in the late postoperative period and clinical scores improved over time. However, in the LRT group, IFFR and PFFR progressed in the early and late postoperative periods and clinical scores did not improve at the late postoperative follow-up.

[Lesions of the rotator cuff and biceps tendon]

CLINICAL/METHODOLOGICAL PROBLEM

The rotator cuff is a complex anatomical structure and the integrity is pivotal for the shoulder functionality. The pathologies are often multifactorial, resulting from degenerative, vascular, traumatic and mechanical factors.

RADIOLOGICAL STANDARD PROCEDURES

Radiography, ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) form the pillars of radiological diagnostics. Each modality has specific advantages and limitations in the visualization and assessment of pathologies of the rotator cuff and biceps tendon.

METHODOLOGICAL INNOVATIONS

The MR arthrography offers additional insights in unclear cases by enhancing the differentiation between complete and partial tears.

PERFORMANCE

The MRI provides detailed information on tendon quality and associated damages, such as muscle atrophy and fat infiltration, making it the preferred method. The use of MR arthrography can identify defects through increased intra-articular pressure or contrast medium leakage.

EVALUATION

Muscle damage, as induced by edema in acute injuries or fatty degeneration in chronic conditions, can be evaluated using imaging techniques. Special attention is warranted for the infraspinatus, subscapularis and teres minor muscles due to their unique injury patterns and prevalences.

Fatty Degeneration of the Rotator Cuff Muscles Improves in Shoulders with Successful Arthroscopic Rotator Cuff Repair: A Prospective Study Using Quantitative T2 Mapping Techniques, with 2-Year Follow-up

Background

There remain arguments regarding whether fatty degeneration of the rotator cuff muscles improves following rotator cuff repair. The purpose of this study was to prospectively investigate changes in fatty degeneration of the rotator cuff muscles, quantitatively measured on magnetic resonance imaging (MRI) with use of transverse relaxation time (T2) mapping techniques, and to assess the relationship between these changes and clinical outcomes.

Methods

Patients were included if they were scheduled for arthroscopic rotator cuff repair using the suture-bridge technique between June 2014 and December 2015, underwent preoperative MRI including the T2 mapping sequence, and consented to participate in the study. Exclusion criteria consisted of trauma within 2 months before preoperative MRI, isolated subscapularis tears, patch augmentation, neuromuscular disease, and a follow-up duration of <2 years. MRI scans were acquired preoperatively and at 2 years postoperatively, and T2 values of the supraspinatus and infraspinatus muscles were measured, with smaller T2 values indicating less fat content. Shoulders were evaluated on the basis of active range of motion (ROM), Constant and University of California Los Angeles Shoulder Rating Scale scores, shoulder external rotation strength with the arm at the side, and rotator cuff integrity on postoperative MRI.

Results

A total of 103 patients (103 shoulders) with a mean age of 65 ± 9 years (range, 42 to 83 years) were included, of whom 52 were male and 51 were female. There were 13 partial, 18 small, 35 medium, 33 large, and 4 massive tears. Concomitant subscapularis tears were observed in 35 shoulders. Overall, ROM, clinical scores, and external rotation strength significantly improved postoperatively. Retears were found in 27 shoulders (26%). External rotation strength significantly improved postoperatively only in shoulders without a retear. Among shoulders without a retear, the postoperative T2 values of the supraspinatus and infraspinatus were significantly smaller than the preoperative values (p < 0.001 for both); however, no improvement was seen in shoulders with a retear.

Conclusions

Shoulders with successful repair demonstrated significantly smaller T2 values postoperatively as well as significantly improved external rotation strength. Fatty degeneration of the cuff muscles can be reversed, at least in part, and muscle strength improves in shoulders with successful repair.

Level of Evidence

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Muscle belly ratio is the most suitable estimate of the activity of the torn supraspinatus muscle

Background

A torn rotator cuff muscle deteriorates over time leading with an increase in muscle atrophy and fatty infiltration. There are several clinical assessments for evaluating the atrophy of the torn supraspinatus muscle. However, it is unclear which approach can more accurately estimate the activity of the torn supraspinatus muscle. The purpose of this study was to determine which magnetic resonance imaging-based muscle atrophy imaging assessment currently implemented in the clinical setting accurately estimates the activity of the torn supraspinatus muscle.

Methods

Forty patients who were diagnosed with a rotator cuff tear and were candidates for repairs were selected for this study. Cross-sectional area, occupation ratio, and tangent sign were analyzed on T1-weighted oblique sagittal plane magnetic resonance images in which the scapular spine leads to the Y-section. Muscle belly ratio of the supraspinatus muscle was analyzed by calculating the ratio of the width of the muscle belly to the distance from the greater tubercle to the proximal end of the muscle on T1-weighted coronal plane magnetic resonance imaging images. Fatty infiltration was evaluated using the Goutallier classification system. Tear size was obtained intraoperatively by measuring the width and length of the tear and classified based on the Cofield's classification. To assess activity of the torn supraspinatus muscle, participants were first instructed to sit on a chair with the affected arm resting on a table and the shoulder abducted to 60° in the scapular plane with neutral rotation. Elasticity of the supraspinatus muscle belly was then obtained at rest and during isometric contraction using with real-time tissue elastography. Muscle activity, a surrogate for contractility, was defined as the difference between the elasticities measured at rest and during isometric contraction. A stepwise multiple regression analysis was used to investigate independent factors, such as sex, tear width, cross-sectional area, occupation ratio, tangent sign, and muscle belly ratio, related to muscle activity.

Results

Stepwise multiple regression analysis (R2 = 0.522, P < .001) revealed that supraspinatus muscle activity was significantly correlated with muscle belly ratio (β = 0.306, P = .044) and Goutallier stage (β = -0.490, P = .002).

Conclusion

Estimations of muscle belly ratio are most suitable for assessing the activity of a torn supraspinatus muscle compared to other clinical measurements.

The Posterosuperior Tetralogy Scoring System as a Practical Tool to Predict Shoulder Function After Posterosuperior Large-to-Massive Rotator Cuff Repairs

Background

Fatty infiltration (FI) or atrophy alone has been found to be inaccurate in predicting shoulder function after repair of large-to-massive rotator cuff tears (L/MRCTs), especially when a diverse extent of FI and atrophy presents in multiple rotator cuff muscles.

Purpose/Hypothesis

The Posterosuperior Tetralogy Scoring System (PS-Tetra Score), which integrates FI and atrophy, was proposed to predict shoulder function after surgery. It was hypothesized was that a PS-Tetra Score ≥3 would be a risk factor for poor shoulder function after repair of posterosuperior L/MRCTs and would possess greater diagnostic value than using isolated FI or atrophy of the supraspinatus (SSP) or infraspinatus (ISP).

Study Design

Case-control study; Level of evidence, 3.

Methods

A total of 187 arthroscopic repairs of posterosuperior L/MRCTs were reviewed. Magnetic resonance imaging evaluations were performed of FI and atrophy of the SSP and ISP, teres minor hypertrophy, tendon retraction, and acromiohumeral distance. A postoperative American Shoulder and Elbow Surgeons (ASES) score of 70 was used to subgroup patients according to shoulder function. Univariate and multivariate analyses were performed to determine the risk factors of poor shoulder function (ASES ≤70). The diagnostic values of different indicators for predicting shoulder function were evaluated.

Results

In univariate analysis, female sex, higher Goutallier grade of the SSP and ISP, positive SSP tangent sign, and PS-Tetra Score ≥3 was significantly associated with ASES score ≤70, whereas in binary logistic regression analysis, a PS-Tetra Score ≥3 was the only significant risk factor for poor shoulder function. The occurrence rate of poor function in shoulders with a PS-Tetra Score of 0, 1, 2, 3, and 4 was 0% (0/52), 0% (0/52), 19.57% (9/46), 58.06% (18/31), and 83.33% (5/6), respectively. PS-Tetra Score ≥3 possessed higher crude agreement (87.70%), specificity (90.97%), positive predictive value (62.16%), and area under the receiver operating characteristic curve (0.814) than the other 3 indicators, with relatively high negative predictive value (94.00%) and moderate sensitivity (71.88%).

Conclusion

PS-Tetra Score ≥3 was a risk factor of poor shoulder function after repair of posterosuperior L/MRCTs and possessed greater diagnostic value than using isolated FI or atrophy of SSP or ISP alone for predicting shoulder function.

Structural Musculotendinous Parameters That Predict Failed Tendon Healing After Rotator Cuff Repair

Background

Healing of the rotator cuff after repair constitutes a major clinical challenge with reported high failure rates. Identifying structural musculotendinous predictors for failed rotator cuff repair could enable improved diagnosis and management of patients with rotator cuff disease.

Purpose

To investigate structural predictors of the musculotendinous unit for failed tendon healing after rotator cuff repair.

Study Design

Cohort study; Level of evidence, 2.

Methods

Included were 116 shoulders of 115 consecutive patients with supraspinatus (SSP) tear documented on magnetic resonance imaging (MRI) who were treated with an arthroscopic rotator cuff repair. Preoperative assessment included standardized clinical and imaging (MRI) examinations. Intraoperatively, biopsies of the joint capsule, the SSP tendon, and muscle were harvested for histological assessment. At 3 and 12 months postoperatively, patients were re-examined clinically and with MRI. Structural and clinical predictors of healing were evaluated using logistic and linear regression models.

Results

Structural failure of tendon repair, which was significantly associated with poorer clinical outcome, was associated with older age (β = 1.12; 95% CI, 1.03 to 1.26; P = .03), shorter SSP tendon length (β = 0.89; 95% CI, 0.8 to 0.98; P = .02), and increased proportion of slow myosin heavy chain (MHC)-I/fast MHC-II hybrid muscle fibers (β = 1.23; 95% CI, 1.07 to 1.42; P = .004). Primary clinical outcome (12-month postoperative Constant score) was significantly less favorable for shoulders with fatty infiltration of the infraspinatus muscle (β = -4.71; 95% CI, -9.30 to -0.12; P = .044). Conversely, a high content of fast MHC-II muscle fibers (β = 0.24; 95% CI, 0.026 to 0.44; P = .028) was associated with better clinical outcome.

Conclusion

Both decreased tendon length and increased hybrid muscle fiber type were independent predictors for retear. Clinical outcome was compromised by tendon retearing and increased fatty infiltration of the infraspinatus muscle. A high content of fast MHC-II SSP muscle fibers was associated with a better clinical outcome.

Registration

NCT02123784 (ClinicalTrials.govidentifier).

Rotator cuff repairs with all-suture tape anchors: no difference in outcomes between with or without all-suture tape anchors

PURPOSE

This study aimed at comparing the outcomes of medium- to large-sized rotator cuff repairs performed using the suture bridge technique either with or without tape-like sutures, and single row techniques with conventional sutures.

METHODS

A total of 135 eligible patients with medium to large rotator cuff tears were identified and analyzed retrospectively, from 2017 to 2019. Only repairs using all-suture anchors were included in the study. Patients were divided into the following three groups: single-row (SR) repair (N = 50), standard double-row suture bridge (DRSB) repair with conventional sutures (N = 35), and DRSB with tape-like sutures (N = 50). The average postoperative follow-up period was 26.3 ± 9.8 months (range, 18-37).

RESULTS

DRSB with tapes had the highest re-tear rate of 16% (8/50), but there was no significant difference with the re-tear rates observed in SR (8%, 4/50) and DRSB with conventional sutures (11.4%, 4/35) (n.s.). DRSB with tapes demonstrated higher rate of type 2 re-tears (10%) compared to type 1 re-tears (6%), but the other two groups showed either similar or higher rates of type 1 re-tears compared to that of type 2. Post-operative functional scores of the three groups improved significantly (all p < 0.05), but the differences between the groups were not statistically significant.

CONCLUSIONS

No clinical difference in functional outcomes and re-tear rates were observed in DRSB with tapes when compared with SR and DRSB using the conventional sutures. Tape-like DRSB suture which was expected to be superior by its biomechanical advantage was clinically non-superior to conventional DRSB suture. There were no significant differences in VAS scores and UCLA scores.

LEVEL OF EVIDENCE

Level III.

Anatomic characteristics of shoulder based on MRI accurately predict incomplete rotator cuff injuries in patients: relevance for predictive, preventive, and personalized healthcare strategies

Background and PPPM-related working hypothesis

In the diagnosis of incomplete rotator cuff injuries (IRCI), magnetic resonance imaging (MRI) and ultrasound examination often have false-positive and false-negative results, while arthroscopy is expensive, invasive, and complex. From the strategy of predictive, preventive, and personalized medicine (PPPM), shoulder anatomical characteristics based on MRI have been demonstrated to accurately predict IRCI and their clinical applicability for personalized prediction of IRCI.

Aims

This study aimed to develop and validate a nomogram based on anatomical features of the shoulder on MRI to identify IRCI for PPPM healthcare strategies.

Methods

The medical information of 257 patients undergoing preoperative MRI examination was retrospectively reviewed and served as the primary cohort. Partial-thickness rotator cuff tears (RCTs) and tendinopathy observed under arthroscopy were considered IRCI. Using logistic regression analyses and least absolute shrinkage and selection operator (LASSO), IRCI was identified among various preoperative factors containing shoulder MRI and clinical features. A nomogram was constructed and subjected to internal and external validations (80 patients).

Results

The following eight independent risk factors for IRCI were identified:AgeThe left injured sidesThe Goutallier classification of supraspinatus in oblique coronal positionThe Goutallier classification of supraspinatus in the axial positionAcromial thicknessAcromiohumeral distanceCoracohumeral distanceAbnormal acromioclavicular joint signalsThe nomogram accurately predicted IRCI in the development (C-index, 0.932 (95% CI, 0.891, 0.973)) and validation (C-index, 0.955 (95% CI, 0.918, 0.992)) cohorts. The calibration curve was consistent between the predicted IRCI probability and the actual IRCI ratio of the nomogram. The decision curve analysis and clinical impact curves demonstrated that the model had high clinical applicability.

Conclusions

Eight independent factors that accurately predicted IRCI were determined using MRI anatomical findings. These personalized factors can prevent unnecessary diagnostic interventions (e.g., arthroscopy) and can assist surgeons in implementing individualized clinical decisions in medical practice, thus addressing the goals of PPPM.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13167-023-00333-5.

Outcome of intraoperative injection of collagen in arthroscopic repair of full-thickness rotator cuff tear: a retrospective cohort study

BACKGROUND

Rotator cuff (RC) pathologies are considered the most common cause of shoulder disability and pain. Arthroscopic repair of RC tears has proven to be an effective operation. Nonhealing and retear remain significant clinical problems and a challenge to surgeons. In addition, the essential biological augment to enhance RC tendon-bone healing is still under research. The purpose of the study was to assess the safety and efficacy of injection of atelocollagen and acellular dermal matrix (ADM) allograft in arthroscopic repair of full-thickness RC tears.

METHODS

From January 2018 to March 2020, a total of 129 patients with full-thickness RC tear were treated by arthroscopic repair only (group 1, n = 36, with a mean age = 63.2 years), arthroscopic repair together with atelocollagen 1-mL injection (group 2, n = 44, with a mean age = 63 years), or RC tears together with ADM allograft 1-mL injection (group 3, n = 49, with a mean age = 64.6 years). They were prospectively studied. This study included patients with a repairable full-thickness tear of the supraspinatus tendon size <5 cm. We excluded patients with isolated tears of the subscapularis tendon, those with a previous shoulder surgery, and those who had any type of injection for less than 6 weeks. American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form score, Constant Shoulder score, visual analog scale pain score, and range of motion were evaluated preoperatively, at 3, 6, and 12 months of the postoperative period and the final follow-up. In addition, magnetic resonance imaging was performed at 2 months and 12 months postoperatively.

RESULTS

The mean follow-up period was 20 months. All groups showed improvement in functional and pain score at the final follow-up; however, there is no superior outcome among the 3 groups (P > .05). After 2 months, the nonhealing rate was 11% (4 of 36) for group 1, 4% (2 of 44) for group 2, and 2% (1 of 49) for group 3 (P > .05). The retear rates after 12 months was 19.4% (7 of 36) for group 1, 13.6% (6 of 44) for group 2, and 20.4% (10 of 49) for group 3 (P > .05). Adverse events were not detected in any groups.

CONCLUSION

Our study did not show superior clinical or radiologic outcomes of atelocollagen and ADM allograft injections in arthroscopic RC repair over 12 months of follow-up in comparison to the control group. However, adverse events related to atelocollagen and ADM allograft injection were not observed.

Objective analysis of partial three-dimensional rotator cuff muscle volume and fat infiltration across ages and sex from clinical MRI scans

Objective analysis of rotator cuff (RC) atrophy and fatty infiltration (FI) from clinical MRI is limited by qualitative measures and variation in scapular coverage. The goals of this study were to: develop/evaluate a method to quantify RC muscle size, atrophy, and FI from clinical MRIs (with typical lateral only coverage) and then quantify the effects of age and sex on RC muscle. To develop the method, 47 full scapula coverage CTs with matching clinical MRIs were used to: correct for variation in scan capture, and ensure impactful information of the RC is measured. Utilizing this methodology and automated artificial intelligence, 170 healthy clinical shoulder MRIs of varying age and sex were segmented, and each RC muscle's size, relative contribution, and FI as a function of scapula location were quantified. A two-way ANOVA was used to examine the effect of age and sex on RC musculature. The analysis revealed significant (p < 0.05): decreases in size of the supraspinatus, teres minor, and subscapularis with age; decreased supraspinatus and increased infraspinatus relative contribution with age; and increased FI in the infraspinatus with age and in females. This study demonstrated that clinically obtained MRIs can be utilized for automatic 3D analysis of the RC. This method is not susceptible to coverage variation or patient size. Application of methodology in a healthy population revealed differences in RC musculature across ages and FI level between sexes. This large database can be used to reference expected muscle characteristics as a function of scapula location and could eventually be used in conjunction with the proposed methodology for analysis in patient populations.

Evaluation of the acromion variants in MRI and their association with rotator cuff injuries in non-traumatic patients

Purpose

Understanding demographic and MRI parameters with determinant role in rotator cuff tearing (RCT) is required to predict outcomes and select more appropriate treatment in patients with non-traumatic shoulder pain. This study aimed to survey the association of rotator cuff tears with these factors.

Methods

We performed this cross-sectional study on patients referred to Kashani Hospital with non-traumatic shoulder pain suspected of rotator cuff injuries from April 2020 to February 2021. We obtained their demographic data and MRI from electronic hospital records. After that, two radiologists reviewed MRI and recorded data. We employed the SPSS 23 software to organize the obtained results and statistical evaluations.

Results

371 subjects, with the age of 48.61 ± 14.89 years, were included in our study, and 50% of them were male. The flat and down-sloping acromion and partial tearing of the supra and infraspinatus tendons were more frequent than the others. Gender could not consider as a determinant factor for the severity of tendon injuries, acromion types and variants. The relation of age to acromion morphology and the tendinopathy severity was significant. Remarkably, down-sloping acromion was higher at all the acromion shapes; however, it makes no difference in the level of supra and infraspinatus involvement. Moreover, we found that partial tearing was higher in all acromion types, except concave. This distribution was significant only for supraspinatus tears.

Conclusion

The clinical decision is the most important step in patients with RCT and MRI prognostic factors, which are helpful to improve the management of the cases. RCT in older patients and down-slope acromion was more severe than the others. According to the previous studies, acromion morphology (as an important determinant factor) in RCT could be influenced by age, as well.

[Translated article] Correlation between the incidence of rotator cuff lesion in traumatic unilateral anterior glenohumeral dislocation and the contralateral shoulder

INTRODUCTION

Anterior glenohumeral dislocation in patients older than 60 years is related to rotator cuff lesion because of its pre-existing degenerative condition. However, in this age group, the scientific evidence fails to elucidate whether rotator cuff lesions are the cause or consequence of recurrent shoulder instability. The objective of this paper is to describe the prevalence of rotator cuff injuries in a series of consecutive shoulders in patients older than 60 years who suffered a first episode of traumatic glenohumeral dislocation, and its correlation with rotator cuff injuries in both shoulders.

METHODS

Retrospectively, 35 patients over 60 years of age who had a first episode of unilateral traumatic anterior glenohumeral dislocation and who had MRI of both shoulders were studied, evaluating both shoulders with MRI to determine the structural damage correlation of the rotator cuff and long head of the biceps between them.

RESULTS

When assessing the existence of partial or complete injury to the supraspinatus and infraspinatus tendons, the concordance on the affected and healthy sides, we have shown concordant results on both sides in 88.6 and 85.7%, respectively. The Kappa concordance coefficient was 0.72 for supraspinatus and infraspinatus tendons tear. Of the total of 35 cases evaluated, 8 (22.8%) presented at least some alteration in the tendon of the long head of the biceps on the affected side and only one (2.9%) on the healthy side, where the Kappa coefficient of concordance was 0.18. Of the 35 cases evaluated, 9 (25.7%) presented at least some retraction in the tendon of the subscapularis muscle on the affected side, while no participant showed signs of retraction in the tendon of this muscle on the healthy side.

CONCLUSIONS

Our study has found a high correlation of the presence of a postero-superior rotator cuff injury after presenting a glenohumeral dislocation between the shoulder that has suffered the event and the presumably healthy contralateral shoulder. Nevertheless, we have not found this same correlation with subscapularis tendon injury and medial biceps dislocation.

Association of Severe Histological Degeneration of the Torn Supraspinatus Tendon and Retear After Arthroscopic Repair of Full-Thickness Rotator Cuff Tears Using the Suture Bridge Technique

BACKGROUND

Previous studies have demonstrated several prognostic factors for retear after arthroscopic rotator cuff repair (ARCR). However, studies that histologically evaluate the quality of the torn rotator cuff (RC) tendon and its association with postoperative outcomes are limited.

PURPOSE

To investigate factors associated with retear after ARCR using the suture bridge (SB) technique, including the degree of histological degeneration of the RC tendon edge.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

The authors retrospectively evaluated 187 patients who underwent ARCR for full-thickness tears using the SB technique; intraoperative biopsy samples were taken to assess the degree of histological degeneration using the Bonar score. The cohort was divided into healed (n = 165) and retear (n = 22) groups according to magnetic resonance imaging results obtained ≥6 months postoperatively. The evaluation included preoperative patient data (age, sex, symptom duration, trauma history, history of heavy manual work, smoking habit, hypertension, diabetes mellitus, and hyperlipidemia) and radiological data (Hamada classification, Patte classification, Goutallier classification, and global fatty degeneration index [GFDI]). Additionally, intraoperative data (anteroposterior tear size, Lafosse classification for concomitant subscapularis tendon tear, and long head of biceps injury) and preoperative and postoperative clinical findings (active range of motion, University of California, Los Angeles [UCLA], score) were evaluated.

RESULTS

The retear rate was 11.8%. The retear group had a higher percentage of men (P = .031), higher Bonar score (P < .001), higher mean GFDI value (P = .002), higher rate of tear retraction degree (P = .010), and larger anteroposterior tear size (P = .020) than the healed group. The retear group had lower postoperative internal rotation (P = .031) and lower UCLA score (P < .001). Multivariate logistic regression analysis with a stepwise variable selection revealed anteroposterior tear size (odds ratio [OR], 2.4; 95% CI, 1.3-4.5; P = .004) and Bonar score (OR, 1.7; 95% CI, 1.3-2.4; P < .001) as independent predictors for a retear.

CONCLUSION

The results indicate that end-stage severe tendon degeneration might affect retear. Therefore, further investigation on the progression mechanisms of tendon degeneration and development of methods to assess degenerative tissue might improve clinical outcomes after ARCR.

MRI findings of traumatic and degenerative rotator cuff tears and introduction of the "cobra sign"

Background

A rotator cuff tear (RCT) is a common shoulder diagnosis and its etiology may be acute, traumatic, or chronic degenerative. Differentiation between the 2 etiologies may be important for multiple reasons, but remains difficult based on imaging. Further knowledge about radiographic and magnetic resonance findings to distinguish traumatic from degenerative RCT is needed.

Methods

We analyzed magnetic resonance arthrograms (MRAs) of 96 patients with traumatic or degenerative superior RCT, which were matched according their age and the affected rotator cuff muscle into the 2 groups. Patients older than 66 years of age were excluded from the study to avoid including cases with pre-existing degeneration. In the case of traumatic RCT, the time between the trauma and MRA had to be less than 3 months. Various parameters of the supraspinatus (SSP) muscle-tendon unit were assessed (tendon thickness, presence of a remaining tendon stump at the greater tubercle, magnitude of retraction, layer appearance). The retraction of the 2 SSP layers were individually measured to determine the difference of retraction. Additionally, edema of the tendon and muscle, the tangent- and kinking-sign as well as the newly introduced Cobra-sign (bulging of the distal part of the ruptured tendon with slim configuration of the medial part of the tendon) were analyzed.

Results

Edema within the SSP muscle (sensitivity 13%, specificity 100%, P = .011) or the tendon (sensitivity 86%, specificity 36%, P = .014) are more frequent in traumatic RCT. The same association was found for the kinking-sign (sensitivity 53%, specificity 71%, P = .018) and the Cobra sign (sensitivity 47%, specificity 84%, P = .001). Even though not statistically significant, tendencies were observed toward thicker tendon stumps in traumatic RCT, and greater difference in retraction between the 2 SSP layers in the degenerative group. The cohorts had no difference in the presence of a tendon stump at the greater tuberosity.

Conclusion

Muscle and tendon edema, as well as tendon kinking appearance and the newly introduced cobra-sign are suitable MRA parameters to distinguish between traumatic and degenerative etiology of a superior RTC.

Effect of Retear After Arthroscopic Rotator Cuff Repair on Return to Work and Sports in Nonathletes: A Retrospective Cohort Study

Background

The impact of retear after arthroscopic rotator cuff repair (ARCR) on clinical outcomes of patients remains controversial.

Purpose/Hypothesis

The purpose of this study was to determine the effects of retear on strength recovery, return to previous levels of work, and return to sports participation. It was hypothesized that retears (1) would not have a significant effect on patient-reported outcome measures (PROMs) and (2) would significantly inhibit strength recovery and return to previous work and sports.

Study Design

Cohort study; Level of evidence, 3.

Methods

The authors collected data from patients who underwent ARCR between January 2015 and December 2019. All included patients had undergone magnetic resonance imaging (MRI) and strength measurements 1 year postoperatively. Minimum 2-year postoperative PROMs (Constant score, pain visual analog scale, American Shoulder and Elbow Surgeons score, and Single Assessment Numeric Evaluation) and status on work and sports participation were collected, and PROM scores, strength recovery (percentage compared with the contralateral shoulder), return to work, and return to sports were compared between patients with versus without retear on 1-year postoperative MRI. Additionally, factors related to return to work and sports were identified through multivariable regression analysis.

Results

A total of 159 patients were included, of whom 19 (11.9%) had evidence of retear. Return-to-work and return-to-sports status was evaluated in 134 (84.3%) and 93 (58.5%) patients, respectively. There were no significant differences in PROM scores between patients with and without retears; however, patients with retears exhibited significantly worse supraspinatus strength recovery (73% vs 86%; P = .018) and external rotation strength recovery (78% vs 88%; P = .030) compared with patients with intact shoulders. There were no between-group differences in return to work or sports. Active workload was associated with unsuccessful return to work, whereas preoperative participation in shoulder sports was associated with successful return to work.

Conclusion

Patients with postoperative retears had significantly worse postoperative strength recovery than patients with intact shoulders. Active workload and preoperative shoulder sports participation were factors associated with ability to return to work.

Association Between Supraspinatus Tendon Retraction, Histologic Myofiber Size, and Supraspinatus Muscle Atrophy on MRI

BACKGROUND

Atrophy of the rotator cuff is a negative prognostic indicator after rotator cuff repair. Although full-thickness rotator cuff tears accompanied by tendon retraction are commonly associated with decreased muscle cross-sectional area (CSA) on magnetic resonance imaging (MRI), it is unclear whether this is accompanied by histologic atrophy of rotator cuff myofibers.

PURPOSE

To evaluate the effect of supraspinatus tendon retraction and myofiber size on supraspinatus atrophy on MRI.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Supraspinatus muscle biopsy specimens were obtained from consecutive patients undergoing arthroscopic shoulder surgery. Rotator cuff tears were classified according to size. Preoperative MRI was used to measure tendon retraction and CSA of the supraspinatus muscle in the Y-shaped view. The occupation ratio of the supraspinatus was calculated by dividing the supraspinatus CSA by the supraspinatus fossa CSA. Muscle biopsy specimens were examined using laminin to quantify myofiber CSA. The association between supraspinatus tear size and measures of histologic and MRI muscle atrophy were compared using standard statistical tests. Multivariable logistic regression analysis was used to identify independent predictors of muscle atrophy on MRI.

RESULTS

A total of 38 patients were included: 8 with no tear, 14 with a partial-thickness tear, and 16 with a full-thickness tear. Increasing tear size was associated with greater distance of tendon retraction (P < .001), smaller mean histologic myofiber size (P = .004), lower mean supraspinatus CSA on MRI (P < .001), and lower occupation ratio: 0.73 (control), 0.66 (partial tear), 0.53 (small to medium full-thickness tear), and 0.38 (large to massive full-thickness) (P < .001). On Pearson correlation analysis, tendon retraction demonstrated strong correlation with occupation ratio (-0.725; P < .001) and weak correlation with myofiber size (-0.437; P = .006), while occupation ratio showed moderate correlation with myofiber size (0.593; P < .001). Multivariable linear regression analysis demonstrated that increasing tendon retraction (P < .001), age (P = .034), and smaller histologic myofiber CSA (P = .047) were independently associated with greater supraspinatus atrophy on MRI.

CONCLUSION

Supraspinatus muscle atrophy appreciated on MRI is independently associated with patient age, tendon retraction, and atrophy of the supraspinatus myofibers at the histologic level.

Massive and Irreparable Rotator Cuff Tears: A Review of Current Definitions and Concepts

Background

While massive and irreparable rotator cuff tears (MIRCTs) have been abundantly studied, inconsistent definitions in the literature and theories about pain and dysfunction related to them can be difficult to navigate when considering an individual patient.

Purpose

To review the current literature for definitions and critical concepts that drive decision-making for MIRCTs.

Study Design

Narrative review.

Methods

A search of the PubMed database was performed to conduct a comprehensive literature review on MIRCTs. A total of 97 studies were included.

Results

Recent literature reflects added attention to clarifying the definitions of "massive, "irreparable," and "pseudoparalysis." In addition, numerous recent studies have added to the understanding of what generates pain and dysfunction from this condition and have reported on new techniques for addressing them.

Conclusion

The current literature provides a nuanced set of definitions and conceptual foundations on MIRCTs. These can be used to better define these complex conditions in patients when comparing current surgical techniques to address MIRCTs, as well as when interpreting the results of new techniques. While the number of effective treatment options has increased, high-quality and comparative evidence on treatments for MIRCTs is lacking.