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

Medialized rotator cuff repair for retracted, massive, postero superior tears: Clinical and radiological outcomes

INTRODUCTION

The footprint medialization allows a tension free repair in severely retracted rotator cuff tears (RCT), thereby de-creasing the rate of retear. The purpose of the study was to evaluate the clinical and radiological results in a cohort of chronic RCT treated with medialized repair. Secondary purpose was to analyze the impact of medialization length on shoulder function and tendon healing.

HYPOTHESIS

It was hypothesized that the medialization length would have an impact on clinical and radiological outcome.

MATERIAL AND METHODS

A consecutive series of thirty patients that underwent arthroscopic repair of a massive posterosuperior RCT at a single institution were retrospectively studied at mean follow-up 18.4months (SD 15.3; range 9-58). The medialization of the medial footprint was measured intraoperatively. Preoperative and postoperative examination included active range of motion, abduction strength, pain assessment, and functional scores. The postoperative rotator cuff integrity was evaluated according to the Sugaya's classification. Types IV-V were categorized as absence of healing.

RESULTS

At final follow-up the clinical outcomes were significantly improved in all patients (p≤0.001) with the exception of external rotation that displayed no significant improvement (p=0.05). In group 1 (n=8) medialization length was≤10mm (mean 8, SD 1.9) and in group 2 (n=14)>10mm (mean 12.6, SD 1.7). There were no significant differences regarding preoperative and postoperative clinical outcomes (p>0.05) between two groups. Group 2 demonstrated moderate correlation between length of medialization and Sugaya stage of tendon healing (r=0.53, p=0.049). Absence of healing was noted in 4/22 patients, 1/8 in group 1 and 3/14 in group 2.

DISCUSSION

Medialized repair is an effective technique for treating chronic, massive and retracted posterosuperior RCT. A medialization of the footprint less than or equal to 10mm is recommended, as it was associated with good clinical and radiological results. The rate of tendon healing decreases when medialization exceeds 10mm.

LEVEL OF EVIDENCE

III.

Interpositional scaffold anchor rotator cuff footprint tear repair: excellent survival, healing, and early outcomes

PURPOSE

Shoulder function limitation duration after a full-thickness rotator cuff tendon (RCT) tear may influence post-repair healing and outcomes. A suture anchor was developed to improve footprint repair fixation and healing through biological fluid delivery and scaffold augmentation. The primary multicenter study objective was to evaluate RCT repair failure rate based on 6-month MRI examination, and device survival at 1-year follow-up. The secondary objective was to compare the clinical outcomes of subjects with shorter- and longer-term shoulder function limitation duration.

METHODS

Seventy-one subjects (46 men) with moderate-to-large RCT tears (1.5-4 cm), at a median 61 years of age (range = 40-76), participated in this study. Pre-repair RCT tear location/size and 6-month healing status were confirmed by an independent radiologist. Subjects with shorter- (Group 1: 17.8 ± 21 days, n = 37) and longer-term (Group 2: 185.4 ± 89 days, n = 34) shoulder function limitation durations were also compared over 1 year for active mobility, strength, American Shoulder and Elbow Surgeon's Shoulder Score (ASES score), Veterans RAND 12 Item Health Survey (VR-12), and visual analog scale (VAS) pain and instability scores.

RESULTS

Three of the 52 subjects [5.8%] who underwent 6-month MRI experienced a re-tear at the original RCT footprint repair site. By the 1-year follow-up, overall anchor survival was 97%. Although Group 2 displayed lower ASES and VR-12 scores pre-repair (ASES = 40.1 ± 17 vs. 47.9 ± 17; VR-12 physical health (PH) = 37.2 ± 9 vs. 41.4 ± 8) (p ≤ 0.048), at 3-month post-RCT repair (ASES = 61.3 ± 19 vs. 71.3 ± 20; VR-12 PH = 40.8 ± 8 vs. 46.8 ± 9) (p ≤ 0.038), and at 6-month post-RCT repair (ASES = 77.4 ± 18 vs. 87.8 ± 13; VR-12 PH = 48.9 ± 11 vs. 54.0 ± 9) (p ≤ 0.045), by 1-year post-RCT repair, groups did not differ (n.s.). Between-groups VR-12 mental health score differences were not evident at any time period (n.s.). Shoulder pain and instability VAS scores also did not differ (n.s.), displaying comparable improvement between groups from pre-RCT repair to 1-year post-RCT repair. Groups had comparable active shoulder mobility and strength recovery at each follow-up (n.s.).

CONCLUSION

At 6-month post-RCT repair, only 3/52 of patients [5.8%] had a footprint re-tear, and at 1-year follow-up, overall anchor survival was 97%. Use of this scaffold anchor was associated with excellent early clinical outcomes regardless of shoulder function impairment duration.

LEVEL OF EVIDENCE

II.

Histological, radiological and clinical analysis of the supraspinatus tendon and muscle in rotator cuff tears

BACKGROUND

Macroscopic alterations of the affected rotator cuff (RC) are undoubtedly linked to microscopic changes, but they may underestimate the actual degree of the disease. Moreover, it remains unclear whether preoperative structural RC changes may alter clinical outcomes.

METHODS

Supraspinatus tendon and muscle samples were collected from 47 patients undergoing RC surgery. Tendons were evaluated histologically according to the Bonar score; fatty infiltration and muscle atrophy were quantified using a software for biomedical image analysis (ImageJ) in percentage of area affected in the observed muscle section. Preoperative shoulder ROM and pain were evaluated. Radiological muscle atrophy was evaluated with the Tangent Sign and Occupation Ratio; fatty infiltration was assessed according to the Goutallier classification. Correlations between histological, radiological and clinical outcomes were assessed. Statistics were performed using the Spearman correlation coefficient. Intraobserver and interobserver agreement was calculated.

RESULTS

Histopathologic fatty infiltration (r = 0.007, p = 0.962), muscle atrophy (r = 0.003, p = 0.984) and the total Bonar score (r = 0.157, p = 0.292) were not correlated to preoperative shoulder pain. Muscle atrophy showed a significant but weak negative correlation with the preoperative movement of abduction (r = -0.344, p = 0.018). A significant but weak positive correlation was found between muscle atrophy and the total Bonar score (r = 0.352, p = 0.015). No correlation between histological and radiological evaluation was found for both fatty infiltration (r = 0.099, p = 0.510) and muscle atrophy (Tangent Sign: r = -0.223, p = 0.131; Occupation Ratio: r = -0.148, p = 0.319). Our histological evaluation showed a modal value of 3 (out of 3) for fatty infiltration and an equal modal value of 2 and 3 (out of 3) for muscle atrophy. In contrast, the modal value of the Goutallier score was 1 (out of 4) and 28 patients out of 47 showed a negative Tangent sign. At histology, intraobserver agreement ranged from 0.59 to 0.81 and interobserver agreement from 0.57 to 0.64. On the MRI intraobserver agreement ranged from 0.57 to 0.71 and interobserver agreement ranged from 0.53 to 0.65.

CONCLUSIONS

Microscopic muscle atrophy appeared to negatively correlate with the movement of abduction leading to functional impairment. Shoulder pain did not show any relationship with microscopic changes. Radiological evaluation of the supraspinatus muscle alterations seemed to underestimate the degree of the same abnormalities evaluated at histology.

Application of deep learning-based image reconstruction in MR imaging of the shoulder joint to improve image quality and reduce scan time

OBJECTIVES

To compare the image quality and diagnostic performance of conventional motion-corrected periodically rotated overlapping parallel line with enhanced reconstruction (PROPELLER) MRI sequences with post-processed PROPELLER MRI sequences using deep learning-based (DL) reconstructions.

METHODS

In this prospective study of 30 patients, conventional (19 min 18 s) and accelerated MRI sequences (7 min 16 s) using the PROPELLER technique were acquired. Accelerated sequences were post-processed using DL. The image quality and diagnostic confidence were qualitatively assessed by 2 readers using a 5-point Likert scale. Analysis of the pathological findings of cartilage, rotator cuff tendons and muscles, glenoid labrum and subacromial bursa was performed. Inter-reader agreement was calculated using Cohen's kappa statistic. Quantitative evaluation of image quality was measured using the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR).

RESULTS

Mean image quality and diagnostic confidence in evaluation of all shoulder structures were higher in DL sequences (p value = 0.01). Inter-reader agreement ranged between kappa values of 0.155 (assessment of the bursa) and 0.947 (assessment of the rotator cuff muscles). In 17 cases, thickening of the subacromial bursa of more than 2 mm was only visible in DL sequences. The pathologies of the other structures could be properly evaluated by conventional and DL sequences. Mean SNR (p value = 0.01) and CNR (p value = 0.02) were significantly higher for DL sequences.

CONCLUSIONS

The accelerated PROPELLER sequences with DL post-processing showed superior image quality and higher diagnostic confidence compared to the conventional PROPELLER sequences. Subacromial bursa can be thoroughly assessed in DL sequences, while the other structures of the shoulder joint can be assessed in conventional and DL sequences with a good agreement between sequences.

KEY POINTS

• MRI of the shoulder requires long scan times and can be hampered by motion artifacts. • Deep learning-based convolutional neural networks are used to reduce image noise and scan time while maintaining optimal image quality. The radial k-space acquisition technique (PROPELLER) can reduce the scan time and has potential to reduce motion artifacts. • DL sequences show a higher diagnostic confidence than conventional sequences and therefore are preferred for assessment of the subacromial bursa, while conventional and DL sequences show comparable performance in the evaluation of the shoulder joint.

The robustness of glenohumeral centering measurements in dependence of shoulder rotation and their predictive value in shoulders with rotator cuff tears

OBJECTIVE

De-centering of the shoulder joint on radiographs is used as indicator for severity of rotator cuff tears and as predictor for clinical outcome after surgery. The objective of the study was to assess the effect of malrotation on glenohumeral centering on radiographs and to identify the most reliable parameter for its quantification.

SUBJECTS AND METHODS

In this retrospective study (2014-2018), 249 shoulders were included: 92 with imaging-confirmed supra- and infraspinatus tears (rupture; 65.2 ± 9.9 years) and 157 without tears (control; 41.1 ± 13.0 years). On radiographs in neutral position and external rotation, we assessed three radiographic parameters to quantify glenohumeral centering: acromiohumeral distance (ACHD), craniocaudal distance of the humeral head and glenoid center (Deutsch), and scapulohumeral arch congruity (Moloney). Non-parametric statistics was performed.

RESULTS

In both positions, only the distance parameters ACHD (< 0.5 mm) and Deutsch (< 1 mm) were comparable in the two study groups rupture and control. Comparing the parameters between the study groups revealed only ACHD to be significantly different with a reduction of more than 2 mm in the rupture group. Among the parameters, ACHD ≤ 6 mm was the only cut-off discriminating rupture (12-21% of the shoulders with ACHD ≤ 6 mm) and control (none of the shoulders with ACHD ≤ 6 mm). Ninety percent of shoulders with ACHD ≤ 6 mm presented with a massive rotator cuff tear (defined as ≥ 67% of the greater tuberosity exposed).

CONCLUSION

Glenohumeral centering assessed by ACHD and Deutsch is not affected by rotation in shoulders with and without rotator cuff tear. An ACHD ≤ 6 mm has a positive predictive value of 90% for a massive rotator cuff tear.

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.

Three-Dimensional Software- and MR-Imaging-Based Muscle Volumetry Reveals Overestimation of Supraspinatus Muscle Atrophy Using Occupation Ratios in Full-Thickness Tendon Tears

Supraspinatus muscle atrophy is widely determined from oblique-sagittal MRI by calculating the occupation ratio. This ex vivo and clinical study aimed to validate the accuracy of 3D software- and MR-imaging-based muscle volumetry, as well as to assess the influence of the tear pattern on the occupation ratio. Ten porcine muscle specimens were volumetrized using the physical water displacement volumetry as a standard of reference. A total of 149 individuals with intact supraspinatus tendons, partial tears, and full-thickness tears had 3T MRI. Two radiologists independently determined occupation ratio values. An excellent correlation with a Pearson’s r of 0.95 for the variables physical volumetry using the water displacement method and MR-imaging-based muscle volumetry using the software was found and formed the standard of reference for the patient study. The inter-reader reliability was 0.92 for occupation ratios. The correlation between occupation ratios and software-based muscle volumes was good in patients with intact tendons (0.84) and partial tears (0.93) but considerably lower in patients with full-thickness tears (0.68). Three-dimensional-software- and MR-imaging-based muscle volumetry is reliable and accurate. Compared to 3D muscle volumetry, the occupation ratio method overestimates supraspinatus muscle atrophy in full-thickness tears, which is most likely due to the medial retraction of the myotendinous unit.

Agreement between intraoperative and MRI assessments of rotator cuff pathology and two MRI-based assessments of supraspinatus muscle atrophy

Background

Magnetic resonance imaging (MRI)-based rotator cuff assessment is often qualitative and subjective; few studies have tried to validate such preoperative assessments. This study investigates relationships of preoperative MRI assessments made by conventional approaches to intraoperative findings of tear type, location, and size or MRI-assessed muscle occupation ratio.

Methods

Intraoperatively, surgeons assessed tear type, location, anterior-posterior (AP) width, and medial-lateral length in 102 rotator cuff repair patients. Two musculoskeletal radiologists independently assessed the preoperative MRI scans for these same parameters and supraspinatus muscle atrophy by both Warner classification and quantitative occupation ratio. Exact agreement proportions, kappa statistics, and correlation coefficients were used to quantify agreement relationships.

Results

Agreement between MRI readers’ and surgeons’ observations of tear status averaged 93% with κ = 0.38, and that of tear location averaged 77% with κ = 0.50. Concordance correlations of MRI and intraoperative measures of anterior-posterior and medial-lateral tear length averaged 0.59 and 0.56 across readers, respectively. Despite excellent interrater agreement on Warner classification (exact agreement proportion 0.91) and occupation ratio (concordance correlation 0.93) separately, correlations between these 2 measures were −0.54 and −0.64 for the 2 readers, respectively. Patients with Warner grade 0 had occupation ratios ranging from 0.5 to 1.5.

Conclusion

Correlations of preoperative MRI tear dimensions and muscle atrophy assessed by conventional approaches with intraoperatively measured tear dimensions and quantitative occupation ratio, respectively, were only fair. Since tear size and muscle atrophy are known strong predictors of outcomes following rotator cuff repair that may influence treatment decisions, surgeons need to be aware of the limitations of MRI methods. Continued development and validation of quantitative preoperative imaging methods to accurately assess these parameters are needed to improve surgical planning and prognosis.

Midterm clinical outcome of uncemented short-stem reversed shoulder arthroplasty

INTRODUCTION

While the incidence of reverse total shoulder arthroplasty (rTSA) is increasing constantly, newer implants with designs other than the classic Grammont geometry are gaining importance. More anatomic inclination angles and lateralization are supposed to have a positive impact on clinical results and complication rates. Presentation of midterm results therefore is important to support these assumptions. The aim of this study was to report the midterm clinical outcome of primary rTSA with an uncemented humeral short-stem prosthesis (USSP) with a humeral inclination angle of 145° and the analysis of different variables on the outcome.

METHODS

This is a retrospective study of all patients with primary rTSA using an USSP and a combined humeral inclination angle of 145° (Ascend™ flex, Stryker) with a minimum clinical follow-up of 2 years. The implant combines a 132.5° inclination for the humeral stem with an additional 12.5° for the polyethylene inlay. Primary outcomes were patient-reported outcome measures: ASES score, simple shoulder test (SST) and subjective shoulder value (SSV). Secondary outcomes were complication and revision rates. We analyzed different variables: preoperatively gender, age, indication for surgery and status of rotator cuff. Also, the glenoid morphology was classified according to Walch and a proximal humerus cortical bone thickness measurement (CBT avg) of 6 mm was used as a threshold for osteoporosis. Postoperatively, we analyzed different radiologic parameters: filling ratio, distalization and lateralization angles according to Boutsiadis.

RESULTS

A total of 84 out of 99 (85%) patients with a mean FU of 46.7 months (range 24-80 months) could be included: 62 women and 22 men with a mean age of 74.7 years. Mean ASES score significantly increased from 47 preoperatively to 85.8 at the last follow-up (p = 0.001). The postoperative SST reached an average of 65.3 and the mean SSV was 83%. None of the variable parameters analyzed could be identified as a risk factor for a lower outcome defined as a SSV < 70. Three patients (3.6%) had a complication: one incomplete lower plexus lesion, one dislocation and one major hematoma. Surgical revision was needed in two cases (2.4%).

CONCLUSION

The midterm clinical outcome of primary reverse total shoulder arthroplasty (rTSA) with an uncemented humeral short stem and a humeral inclination angle of 145° showed good-to-excellent results with a low complication and revision rate independent from a wide range of pre- and postoperative variables. PROMs are comparable to those reported for anatomic TSA with a low complication rate, different to historical studies especially with the Grammont design.

LEVEL OF EVIDENCE

Treatment study, Level IV.

Ultrasound shear wave elastography-derived tissue stiffness is positively correlated with rotator cuff tear size and muscular degeneration

PURPOSE

The purpose of this study is to describe rotator cuff muscle stiffness in patients with different degrees of rotator cuff tear (RCT) severity and to assess its predictive ability for RCT reparability.

METHODS

One hundred and thirty-three consecutive patients who were scheduled to undergo arthroscopic shoulder surgery were prospectively enrolled. Tendon retraction, fatty infiltration, and muscle atrophy were evaluated using magnetic resonance imaging. Shear modulus of supraspinatus (SSP) and infraspinatus (ISP) muscles were measured by ultrasound shear wave elastography (SWE). The tear size and reparability were determined intraoperatively.

RESULTS

There were 97 patients in RCT group and 36 patients in control group. Bilateral shear modulus discrepancy (Δshear modulus) was used to represent rotator cuff stiffness. Severely fatty-infiltrated rotator cuff muscles possessed a significantly higher stiffness compared with their counterparts (SSP: CI 27.8-31.8 vs. 13.5-15.6 kPa, ISP: CI 33.2-38.1 vs. 8.8-11.2 kPa, p < 0.001). The same trend applied to muscles with distinct tendon retraction (SSP: CI 27.7-32.3 vs. 10.9-14.9 kPa, ISP: CI 33.2-38.6 vs. 6.5-11.0 kPa, p < 0.001) and obvious muscle atrophy (SSP: CI 27.9-32.1 vs. 13.6-15.8 kPa, ISP: CI 32.9-38.2 vs. 9.0-11.7 kPa, p < 0.001). Irreparable massive RCT (MRCT) patients had significantly stiffer SSP (CI 27.7-31.9 vs. 13.5-16.5 kPa, p < 0.001) and ISP (CI 33.5-37.8 vs. 10.3-14.8 kPa, p < 0.001) than reparable MRCT. The Δshear modulus of the ISP was a highly accurate predictor of RCT reparability. A cutoff value of 18.0 kPa had a sensitivity of 100% and specificity of 98.8% for irreparable MRCT.

CONCLUSION

Ultrasound SWE-derived rotator cuff muscle stiffness is closely correlated with RCT size and severity.

LEVEL OF EVIDENCE

I.

MRI-based 3-dimensional volumetric assessment of fatty infiltration and muscle atrophy in rotator cuff tears

BACKGROUND

The Goutallier and Warner Classification systems are useful in determining rotator cuff reparability. Data are limited on how accurately the scapular-Y view used in both systems reflects the 3-dimensional (3-D) changes in fatty infiltration (FI) and muscle atrophy (MA). Tendon retraction in the setting of a cuff tear may also influence the perception of these changes. This study's objectives were to (1) measure the 3-D volume of the supraspinatus muscle in intact rotator cuffs, and with varying magnitudes of retraction; (2) measure the 3-D volume of FI in the supraspinatus muscle in these conditions; and (3) determine the influence of tendon retraction on measured FI and MA using the Goutallier and Warner Classification Systems.

METHODS

Between August 2015 and February 2016, all shoulder magnetic resonance images (MRIs) at the Portland VA Medical Center were standardized to include the medial scapular border. MRIs and charts were reviewed for inclusion/exclusion criteria. Included MRIs were categorized into 4 groups based on rotator cuff retraction. Supraspinatus muscle and fossa were traced to create 3-D volumes. FI and MA were measured within the supraspinatus. The supraspinatus muscle was graded among 6 physicians using the Goutallier and Warner classification systems. These grades were compared to 3-D measured FI and MA. The influence of tendon retraction on the measured grades were also evaluated.

RESULTS

One hundred nine patients met inclusion/exclusion criteria. Ten MRIs for each group (N = 40) were included for image analysis. Supraspinatus volume tracings were highly reproducible and consistent between tracers. Supraspinatus muscle volumes decreased while global FI and MA increased with greater degrees of tendon retraction. In muscles with less than 10% global fat, fat concentrated in the lateral third of the muscle. In muscle with more than 10% global fat content, it distributed more diffusely throughout the muscle from medial to lateral. In comparing the scapular-Y to a medial cut, there was no consistent trend in FI whereas MA was more accurate at the medial cut.

CONCLUSION

Parasagittal imaging location did not significantly influence the Goutallier score; however, assessment of MA using the Warner score leads readers to perceive less MA medially regardless of the magnitude of tendon retraction. The pattern of FI within the supraspinatus muscle changes from a laterally based location around the muscle-tendon junction to a more diffuse, global infiltration pattern when the whole muscle fat content exceeds 10%.

Tear pattern after superior capsular reconstruction using an acellular dermal matrix allograft

BACKGROUND

The healing rate and tear pattern of grafts in superior capsular reconstruction (SCR) using acellular dermal matrix (ADM) allograft are poorly understood, and clinical results based on the graft status remain controversial.

METHODS

Fifty-one consecutive patients undergoing arthroscopic SCR with ADM between October 2017 and February 2020 were enrolled. Range of motion, strength, and the visual analog scale pain (PVAS) score, American Shoulder and Elbow Surgeons (ASES) score, and Constant score were evaluated preoperatively and at the last follow-up. Postoperative magnetic resonance imaging was performed in all patients and was obtained at least 6 months (mean, 8.9 ± 3.6 months) after surgery. The graft tear status was analyzed on magnetic resonance imaging, and the numbers of patients who achieved the minimal clinically important difference and patient acceptable symptomatic state were analyzed to determine the differences in outcome according to graft tear status.

RESULTS

The range of motion and clinical results improved at a minimum of 1 year (mean, 18 ± 5.4 months), whereas strength in forward flexion and external rotation did not (P = .676 and P = .995, respectively). The graft was intact in 36 of 51 patients (70.6%), 9 patients (17.6%) showed an incomplete graft tear with maintained continuity (partial graft rupture at 1 anchor on either the glenoid or humeral side), and 6 patients (11.8%) showed complete graft rupture (5 on the glenoid side and 1 on the humeral side). In cases with a tear (either incomplete or complete), the odds of achieving the minimal clinically important difference for the PVAS score (P = .047) and ASES score (P = .020) was significantly lower than that of the intact graft. However, when the continuity of the graft was maintained, even in cases with a partial tear, patients who reached the patient acceptable symptomatic state showed significantly higher odds for the PVAS score and trends for the ASES score.

CONCLUSION

After SCR using ADM, the graft status could be classified as intact, an incomplete graft tear (where the continuity between the glenoid and humerus was maintained), or an complete tear. When the graft continuity was maintained, even in incomplete graft tears, patients were generally satisfied with postoperative pain and function at 1 year following SCR.

Utility of Preoperative Shear-Wave Elastography of the Supraspinatus Muscle for Predicting Successful Rotator Cuff Repair: A Prospective Observational Study With MRI Correlation

BACKGROUND. After rotator cuff tear, properties of the torn muscle predict failed surgical repair. OBJECTIVE. The purpose of our study was to explore the utility of preoperative shear-wave elastography (SWE) measurements of the supraspinatus muscle to predict successful rotator cuff repair, including comparison with MRI-based measures. METHODS. This prospective study included 74 patients (37 men, 37 women; mean age, 63.9 ± 10.0 [SD] years) who underwent rotator cuff repair between May 2019 and January 2021. Patients underwent preoperative clinical shoulder MRI and investigational shoulder ultrasound including SWE using shear modulus. The mean elasticity values of the supraspinatus and trapezius muscles were measured, and the elasticity ratio (i.e., ratio of mean elasticity of supraspinatus muscle to mean elasticity of trapezius muscle) was calculated. The muscular fatty infiltration score (1-3 scale) was recorded on gray-scale ultrasound. On MRI, muscular fatty infiltration was assessed by Goutallier grade (0-4 scale), and muscular atrophy was assessed by the occupation ratio (ratio of cross-sectional areas of supraspinatus muscle and supraspinatus fossa) and by the muscle atrophy grade (0-3 scale). After rotator cuff repair, the surgeon classified procedures as achieving sufficient (n = 60) or insufficient (n = 14) repair. RESULTS. Patients with insufficient repair, versus those with sufficient repair, more commonly exhibited a large (3-5 cm) tear (100.0% vs 50.0%). Patients with insufficient, versus sufficient, repair exhibited higher mean Goutallier grade (3.8 ± 0.4 vs 1.9 ± 1.1), mean muscle atrophy grade (2.0 ± 0.8 vs 0.5 ± 0.7), mean supraspinatus elasticity (44.15 ± 8.06 vs 30.84 ± 7.89 kPa), mean elasticity ratio (3.66 ± 0.66 vs 1.83 ± 0.58), and mean gray-scale fatty infiltration grade (2.86 ± 0.36 vs 1.63 ± 0.66) and showed lower mean occupation ratio (0.3 ± 0.1 vs 0.6 ± 0.1) (all, p < .001). AUC for predicting insufficient repair was 0.945 for Goutallier grade, 0.961 for occupation ratio, 0.900 for muscle atrophy grade, 0.874 for mean elasticity, 0.971 for elasticity ratio, and 0.912 for gray-scale fatty infiltration grade. Elasticity ratio (cutoff ≥ 2.51) achieved sensitivity of 100.0% and specificity of 90.0% for insufficient repair. At multivariable analysis including tear size, the three MRI measures, elasticity ratio, and gray-scale fatty infiltration grade, the only independent predictors of insufficient repair were muscle atrophy grade of 2-3 (odds ratio [OR] = 9.3) and elasticity ratio (OR = 15.7). CONCLUSION. SWE-derived elasticity is higher in patients with insufficient rotator cuff repair; the elasticity ratio predicts insufficient repair independent of tear size and muscle characteristics. CLINICAL IMPACT. Preoperative SWE may serve as a prognostic marker in patients with rotator cuff tear.

Factors correlated with the optimal tension for arthroscopic rotator cuff repair using Grasper Tensioning Attachment

BACKGROUND

Little is known about the optimal tension in arthroscopic rotator cuff repair (ARCR). This study aimed to identify preoperative, intraoperative, and postoperative factors that correlate with the tension in ARCR and to determine the optimal intraoperative tension using Grasper Tensioning Attachment, a tension meter attached to the common arthroscopic surgical grasper.

METHODS

This study included 63 patients with a mean age at surgery of 65.3 years (range, 45-83 years) who underwent ARCR. The mean follow-up period was 24.1 months (range, 24-28 months). We investigated the patients' demographic data, Japanese Orthopaedic Association score, DeOrio and Cofield classification, and Goutallier stage of the supraspinatus and infraspinatus muscles. We also evaluated cuff integrity based on the Sugaya classification via magnetic resonance imaging. The free edge of the torn retracted tendon was grasped, and the passive tension to the footprint was then measured with Grasper Tensioning Attachment with the arm at the side. The anteroposterior (AP) and mediolateral (ML) diameters were also measured.

RESULTS

The preoperative Goutallier stage of the supraspinatus muscle was stage 0 in 7 cases, stage 1 in 34, stage 2 in 20, and stage 3 in 2. The mean intraoperative rotator repair tension was 10.0 ± 2.5 N (range, 7.5-17 N). The mean AP diameter of the rotator cuff tear was 22 ± 10 mm (range, 8-50 mm), and the mean ML diameter was 24 ± 10 mm (range, 10-50 mm). Age, DeOrio and Cofield classification, Goutallier stage, AP diameter, and ML diameter correlated with rotator repair tension. The rotator repair tension in Sugaya classification type III or IV cases (n = 12, 11.4 ± 2.4 N) was significantly larger than that in type I or II cases (n = 51, 9.7 ± 2.4 N; P = .03). Tension ≥ 10 N as a cutoff value from receiver operating characteristic curve analysis was a risk factor for poor cuff integrity (95% confidence interval, 0.53-0.88).

CONCLUSIONS

Rotator repair tension ≥ 10 N was a risk factor for poor cuff integrity. Thus, care should be taken when performing intraoperative procedures and administering postoperative regimens.

Agreement in rotator cuff muscles measurement between ultrasonography and magnetic resonance imaging

Background/objective

It is important to assess the atrophy of the rotator cuff to better understand shoulder function and pain. Previously, magnetic resonance imaging has been used for the evaluation of atrophy of rotator cuff muscles, which is time consuming. Therefore, a measurement tool requiring little time and easy accessibility is clinically desirable to be used frequently in rehabilitation. Recently, rotator cuff muscles have been evaluated using ultrasonography. However, little is known about the agreement of evaluation in rotator cuff muscles between magnetic resonance imaging and ultrasonography. The purpose of this study was to demonstrate the agreement between the muscle thickness measurements of supraspinatus, infraspinatus, and teres minor muscles by ultrasonography and the cross-sectional area measured by magnetic resonance imaging in the patient with rotator cuff tears.

Methods

A total of 47 patients with rotator cuff tears were enrolled. There were the 37 small tears, four medium tears, and six large tears, and the involved rotator cuff muscles were the supraspinatus in 37 shoulders, and the supraspinatus and infraspinatus in 10 shoulders. The measuring variables were muscle thickness and cross-sectional area of supraspinatus, infraspinatus, and teres minor muscles by using magnetic resonance imaging. Further, the muscle thickness of the rotator cuff were assessed using ultrasonography. A single regression model was used for demonstrating the agreement between the cross-sectional area measurement by magnetic resonance imaging and the muscle thickness measured using ultrasonography and magnetic resonance imaging of rotator cuff muscles. Additionally, the Bland-Altman plots between magnetic resonance imaging and ultrasonography was analyzed.

Results

The cross-sectional area were correlated with the muscle thickness measurement of rotator cuff muscles by magnetic resonance imaging, significantly (supraspinatus: r = 0.84, infraspinatus: ρ = 0.63, teres minor: ρ = 0.61, all p < 0.001). There were significant agreements between the cross-sectional area measured by magnetic resonance imaging and muscle thickness measured by ultrasonography (supraspinatus: r = 0.80, infraspinatus: ρ = 0.78, teres minor: ρ = 0.74, all p < 0.001). Bland-Altman plots revealed significant correlations between the average and the difference of the two measurements in supraspinatus (r = 0.36, p = 0.012), infraspinatus (r = 0.38, p < 0.001), and teres minor (r = 0.42, p < 0.001). These results clarified the proportional bias between MRI and US.

Conclusion

This study showed that, similar to magnetic resonance imaging, ultrasonography is a useful tool for assessing muscle atrophy of supraspinatus, infraspinatus, and teres minor muscles.

Superior Capsular Reconstruction Using Acellular Dermal Allograft Combined With Remaining Rotator Cuff Augmentation Improved Shoulder Pain and Function at 1 Year After The Surgery

PURPOSE

The purpose of this study is to report structural integrity and clinical outcomes of superior capsular reconstruction (SCR) using a 4- to 5-mm acellular dermal allograft combined with augmentation of the remaining rotator cuff to the graft.

METHODS

We prospectively recruited 21 patients with symptomatic irreparable rotator cuff tear who required SCR. At least 6 months after the SCR, we evaluated each patient's graft healing by magnetic resonance imaging (MRI). We also assessed the range of motion (ROM), strength for forward flexion and external rotation, visual analog scale for pain (PVAS), American Shoulder and Elbow Surgeon (ASES) score, and Constant score. At minimum of 1 year after the surgery, we evaluated the number of patients with minimal clinically important differences (MCIDs) for each score to compare patients with healed and unhealed grafts.

RESULTS

Postoperative MRI showed the grafts intact in 14 patients (66.7%). Among 7 patients with unhealed grafts, tears were observed in 3 patients (42.9%) on the glenoid side, 3 (42.9%) on the humeral side, and 1 (14.3%) on both sides. PVAS, ASES score, and the Constant score improved after surgery (4.0 to 0.7 for PVAS [P < .001], 55.5 to 87.0 for ASES score [P < .001], and 56.0 to 65.9 for Constant score [P = .007]). However, there were no differences in postoperative ROM and muscle strength compared to preoperative measurements. MCIDs were reached in 90.5% of patients (n = 19) for the PVAS and in 71.4% of patients (n = 15) for the ASES score. Only 33.3% of patients (n = 7) obtained MCIDs for the Constant score, and none of the patients with a graft tear obtained MCIDs in the Constant score (P = .047).

CONCLUSION

The graft complete healing rate was 66.7%, although pain relief and functional improvement were satisfactory regardless of graft structural integrity. However, muscle strength recovery was not optimal until 1 year after surgery.

LEVEL OF EVIDENCE

Level IV; case series.

In Vivo Static Retraction and Dynamic Elongation of Rotator Cuff Repair Tissue After Surgical Repair: A Preliminary Analysis at 3 Months

Background:

Rotator cuff repair is a common orthopaedic procedure that provides pain relief for many patients, but unfortunately, an estimated 20% to 70% of repair procedures will fail. Previous research has shown that elongation (ie, retraction) of a repaired tendon is common even in patients with a repair construct that appears intact on magnetic resonance imaging. However, it is unknown how this repair tissue functions under dynamic conditions.

Purpose:

To quantify static retraction and maximum dynamic elongation of repair tissue after rotator cuff repair.

Study Design:

Case series; Level of evidence, 4.

Methods:

Data from 9 patients were analyzed for this study. During surgery, a 3.1-mm tantalum bead was sutured to the supraspinatus tendon, medial to the repair site. Glenohumeral kinematics were assessed at 1 week (static) and 3 months (static and during scapular-plane abduction) after surgery using a biplanar videoradiographic system. The 3-dimensional position of the bead was calculated relative to the tendon’s insertion on the humerus (ie, bead-to-insertion distance). Static retraction was calculated as the change in the bead-to-insertion distance under static conditions between 1 week and 3 months after surgery, and maximum dynamic elongation was calculated as the maximal positive change in the bead-to-insertion distance during dynamic motion relative to the start of motion. The magnitudes of static retraction and maximum dynamic elongation were assessed with 1-sample t tests.

Results:

At 3 months after surgery, static retraction occurred in all patients by a mean of 10.0 ± 9.1 mm (P = .01 compared with no elongation). During scapular-plane abduction, maximum dynamic elongation averaged 1.4 ± 1.0 mm (P < .01 compared with no elongation). Descriptively, dynamic elongation consistently took 1 of 2 forms: an initial increase in the bead-to-insertion distance (mean, 2.0 ± 0.6 mm) before decreasing until the end of motion or an immediate and substantial decrease in the bead-to-insertion distance at the onset of motion.

Conclusion:

Repair tissue elongation (static retraction and maximum dynamic elongation) appeared to be a common and significant finding at 3 months after arthroscopic rotator cuff repair. Dynamic elongation of repair tissue during scapular-plane abduction exhibited 1 of 2 distinct patterns, which may suggest different patterns of supraspinatus mechanical and neuromuscular function.

Retear bigger than preoperative tear size would lead to treatment failure after rotator cuff repair

BACKGROUND

This study aimed to (1) define treatment failure using the referred patient acceptable symptomatic state (PASS) values for pain visual analog scale (PVAS), American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), and Single Assessment Numeric Evaluation (SANE) clinical scores and (2) identify the factors that lead to patient dissatisfaction after arthroscopic rotator cuff repair (ARCR).

METHODS

We analyzed the arthroscopic rotator cuff surgery registry data from January 2015 to December 2016. Patients were followed for ≥2 years and categorized as dissatisfied or satisfied based on our own definition of treatment failure at 2 years postoperatively. For defining treatment failure, the referred PASS values for the PVAS, ASES, and SANE scores were used. Patients who failed to attain the PASS value for the PVAS, ASES, or SANE score were categorized into the dissatisfied group. Pre- and postoperative imaging and basic demographic data were compared between groups. Univariable and multivariable logistic regression analyses were performed to identify the factors affecting patient satisfaction at 2 years after rotator cuff repair.

RESULTS

Of 117 patients, 30 (25.6%) were defined as the dissatisfied group (mean follow-up period, 37.5 months). Seventeen patients (14.5%) had confirmed retear on follow-up magnetic resonance imaging. In the univariate analysis, sex significantly differed between the groups (female, satisfied vs. dissatisfied groups: 39 [44.8%] vs. 22 [73.3%]; P = .010). Retear alone did not affect patient satisfaction in the univariate analysis (P = .11). Progressed retear size featured a significantly higher risk of patient dissatisfaction (P = .024; odds ratio 6.430, 95% confidence interval 1.270-32.541) in the multivariable analysis using symptom duration, sex, preoperative ASES score, preoperative tear size, retear, and progressed retear size as variables. Moreover, female sex had an increased odds for dissatisfaction (odds ratio 4.646, 95% confidence interval 1.590-13.578; P = .005).

CONCLUSION

Two years after ARCR, most patients (74.4%) reported satisfaction with their outcomes. However, satisfaction levels can be altered by female sex or progressed retear size compared with the preoperative state.

Added value of combined acromiohumeral distance and critical shoulder angle measurements on conventional radiographs for the prediction of rotator cuff pathology

Purpose

Method

Results

Conclusions

•

Acromiohumeral distance (AHD) and critical shoulder angle (CSA) do not depend on age or sex.

•

CSA and AHD are significantly different in healthy and pathologic rotator cuffs.

•

Combining CSA and AHD into one index (PI_AHD-CSA) increases overall diagnostic performance.

•

A high PIAHD-CSA increases the risk of full thickness rotator cuff tear and critical fatty degeneration.

Three-dimensional muscle loss assessment: a novel computed tomography-based quantitative method to evaluate rotator cuff muscle fatty infiltration

BACKGROUND

Rotator cuff fatty infiltration (FI) is one of the most important parameters to predict the outcome of certain shoulder conditions. The primary objective of this study was to define a new computed tomography (CT)-based quantitative 3-dimensional (3D) measure of muscle loss (3DML) based on the rationale of the 2-dimensional (2D) qualitative Goutallier score. The secondary objective of this study was to compare this new measurement method to traditional 2D qualitative assessment of FI according to Goutallier et al and to a 3D quantitative measurement of fatty infiltration (3DFI).

MATERIALS AND METHODS

102 CT scans from healthy shoulders (46) and shoulders with cuff tear arthropathy (21), irreparable rotator cuff tears (18), and primary osteoarthritis (17) were analyzed by 3 experienced shoulder surgeons for subjective grading of fatty infiltration according to Goutallier, and their rotator cuff muscles were manually segmented. Quantitative 3D measurements of fatty infiltration (3DFI) were completed. The volume of muscle fibers without intramuscular fat was then calculated for each rotator cuff muscle and normalized to the patient's scapular volume to account for the effect of body size (NV_fibers). 3D muscle mass (3DMM) was calculated by dividing the NV_fibers value of a given muscle by the mean expected volume in healthy shoulders. 3D muscle loss (3DML) was defined as 1 - (3DMM). The correlation between Goutallier grading, 3DFI, and 3DML was compared using a Spearman rank correlation.

RESULTS

Interobserver reliability for the traditional 2D Goutallier grading was moderate for the infraspinatus (ISP, 0.42) and fair for the supraspinatus (SSP, 0.38), subscapularis (SSC, 0.27) and teres minor (TM, 0.27). 2D Goutallier grading was found to be significantly and highly correlated with 3DFI (SSP, 0.79; ISP, 0.83; SSC, 0.69; TM, 0.45) and 3DML (SSP, 0.87; ISP, 0.85; SSC, 0.69; TM, 0.46) for all 4 rotator cuff muscles (P < .0001). This correlation was significantly higher for 3DML than for the 3DFI for SSP only (P = .01). The mean values of 3DFI and 3DML were 0.9% and 5.3% for Goutallier 0, 2.9% and 25.6% for Goutallier 1, 11.4% and 49.5% for Goutallier 2, 20.7% and 59.7% for Goutallier 3, and 29.3% and 70.2% for Goutallier 4, respectively.

CONCLUSION

The Goutallier score has been helping surgeons by using 2D CT scan slices. However, this grading is associated with suboptimal interobserver agreement. The new measures we propose provide a more consistent assessment that correlates well with Goutallier's principles. As 3DML measurements incorporate atrophy and fatty infiltration, they could become a very reliable index for assessing shoulder muscle function. Future algorithms capable of automatically calculating the 3DML of the cuff could help in the decision process for cuff repair and the choice of anatomic or reverse shoulder arthroplasty.

Inter-rater agreement of rotator cuff tendon and muscle magnetic resonance imaging parameters evaluated preoperatively and during the first postoperative year following rotator cuff repair

BACKGROUND

Magnetic resonance imaging (MRI) is standard of care for rotator cuff evaluation, with clinical interpretation usually limited to qualitative judgments. The reliability of MRI-based measurements and scoring systems has been evaluated only preoperatively or ≥6 months following rotator cuff repair, when repairs are in the later stages of healing. This study describes the MRI assessments and inter-rater agreement of various rotator cuff tendon and muscle parameters evaluated preoperatively and 4 times during the first postoperative year.

METHODS

Two musculoskeletal radiologists independently assessed MRI scans of 42 patients preoperatively and 3, 12, 26, and 52 weeks after rotator cuff repair. Using standardized reading rules, readers assessed tendon integrity (5-point Sugaya classification), tear dimensions, muscle fat (5-point Goutallier classification) and atrophy (4-point Warner classification), muscle cross-sectional areas, and myotendinous junction distance. Raw exact agreement proportions, κ statistics, and correlation coefficients were used to quantify inter-rater agreement.

RESULTS

Readers showed moderate to substantial above-chance agreement in scoring rotator cuff tendon integrity and supraspinatus muscle atrophy and good to excellent agreement on tear dimensions and muscle cross-sectional areas but only fair to moderate agreement for fatty infiltration and myotendinous junction distance. Only fatty infiltration grades evidenced observer bias. Inter-rater agreement did not appear time dependent.

CONCLUSION

By use of defined reading rules in a research setting, MRI evaluations of rotator cuff tendon integrity, tear dimensions, muscle atrophy, and cross-sectional areas have reasonable reliability at all time points in the first postoperative year. However, the presence of clinically significant disagreements, even in such favorable circumstances, indicates the need for improved imaging tools for precise rotator cuff evaluation.

Fatty degeneration of the rotator cuff: pathogenesis, clinical implications, and future treatment

Chronic rotator cuff pathology is often complicated by fatty degeneration of the rotator cuff (FDRC) muscles, an insidious process associated with poor prognosis with or without surgical intervention. Currently there is no treatment for FDRC, and many studies have described a natural course for this disease almost always resulting in further degeneration and morbidity. Recapitulating FDRC using animal injury models, and using imaging-based studies of human FDRC, the pathophysiology of this disease continues to be further characterized. Researchers studying mesenchymal stem cell-derived progenitor cells and known fibrogenic and adipogenic signaling pathways implicated in FDRC seek to clarify the underlying processes driving these changes. While new cell- and molecular-based therapies are being developed, currently the strongest available avenue for improved management of FDRC is the use of novel imaging techniques which allow for more accurate and personalized staging of fatty degeneration. This narrative review summarizes the evidence on the molecular and pathophysiologic mechanisms of FDRC and provides a clinical update on the diagnosis and management of this condition based on the existing knowledge. We also sought to examine the role of newer biologic therapies in the management of RC fatty degeneration and to identify areas of future research.

Postoperative Pain Control After Arthroscopic Rotator Cuff Repair: Arthroscopy-Guided Continuous Suprascapular Nerve Block Versus Ultrasound-Guided Continuous Interscalene Block

PURPOSE

To compare the clinical efficacy and safety of arthroscopy-guided continuous suprascapular nerve block and ultrasound-guided continuous interscalene block in postoperative analgesia in patients undergoing arthroscopic rotator cuff repair.

METHODS

A prospective study was performed between March and November 2020. In total, 76 patients were enrolled and divided into 2 groups: in the 38 patients of group 1 (arthroscopy-guided continuous suprascapular nerve block), an indwelling catheter was introduced via the Neviaser portal under arthroscopic view before closing the portal at the end of the surgery; and in the 38 patients of group 2 (ultrasound-guided continuous interscalene block), an indwelling catheter was inserted and directed toward the interscalene brachial plexus prior to the surgery under ultrasound guidance. The primary outcome was the pain score measured by the visual analog scale at postoperative 24 hours during admission. Comparisons were conducted at different time points (postoperative 4, 8, 24, and 48 hours). The secondary outcome was any of these events: neurologic complications, such as sensory/motor change in the upper extremities; hemidiaphragmatic paresis; dyspnea; dysphonia; and Horner's syndrome. Opioid usage until postoperative 3 weeks was compared between the groups.

RESULTS

The visual analog scale scores in groups 1 and 2 were comparable at each postoperative time point (analysis of variance, P = .919; trends, P = .132). Neurologic deficits were more common in group 2 than in group 1 (8 vs 32 patients, P < .001). Decreased excursion of the diaphragm was more common in group 2 (partial or complete paresis of the hemidiaphragm: 1 vs 29 patients, P < .001). Opioid consumption was similar in both groups (morphine milligram equivalents per kilogram; 1.75 vs 1.55, P = .195).

CONCLUSIONS

Our findings show that arthroscopy-guided continuous suprascapular nerve block is not inferior to ultrasound-guided continuous interscalene block for postoperative pain control after arthroscopic rotator cuff repair while showing fewer temporary neurologic complications.

LEVEL OF EVIDENCE

Level II, prospective cohort study, interventional study.

Presurgical tear characteristics and estimated shear modulus as predictors of repair integrity and shoulder function one year after rotator cuff repair

Background

Rotator cuff repair provides pain relief for many patients; however, retears are relatively common and affect approximately 20%-70% of patients after repair. Although magnetic resonance imaging (MRI) offers the ability to assess tissue characteristics such as tear size, retraction, and fatty infiltration, it provides little insight into the quality of the musculotendinous tissues the surgeon will encounter during surgery. However, shear wave elastography (SWE) could provide an indirect assessment of quality (ie, stiffness) by measuring the speed of shear waves propagating through tissue. The objective of this study was to determine the extent to which estimated shear modulus predicts repair integrity and functional outcomes 1 year after rotator cuff repair.

Methods

Thirty-three individuals scheduled to undergo arthroscopic rotator cuff repair were enrolled in this study. Before surgery, shear modulus of the supraspinatus tendon and muscle was estimated using ultrasound SWE. MRIs were obtained before and 1 year after surgery to assess tear characteristics and repair integrity, respectively. Shoulder strength, range of motion, and patient-reported pain and function were assessed before and after surgery. Functional outcomes were compared between groups and across time using a two-factor mixed model analysis of variance. Stepwise regression with model comparison was used to investigate the extent to which MRI and shear modulus predicted repair integrity and function at 1 year after surgery.

Results

At 1 year after surgery, 56.5% of patients had an intact repair. No significant differences were found in any demographic variable, presurgical tear characteristic, or shear modulus between patients with an intact repair and those with a recurrent tear. Compared with presurgical measures, patients in both groups demonstrated significant improvements at 1 year after surgery in pain (P < .01), self-reported function (P < .01), range of motion (P < .01), and shoulder strength (P < .01). In addition, neither presurgical MRI variables (P > .16) nor shear modulus (P > .52) was significantly different between groups at 1 year after surgery. Finally, presurgical shear modulus generally did not improve the prediction of functional outcomes above and beyond that provided by MRI variables alone (P > .22).

Conclusion

Although SWE remains a promising modality for many clinical applications, this study found that SWE-estimated shear modulus did not predict repair integrity or functional outcomes at 1 year after surgery, nor did it add to the prediction of outcomes above and beyond that provided by traditional presurgical MRI measures of tear characteristics. Therefore, it appears that further research is needed to fully understand the clinical utility of SWE for musculoskeletal tissue and its potential use for predicting outcomes after surgical rotator cuff repair.

Superior Capsular Reconstruction With Autologous Fascia Lata Using a Single Lateral-Row Technique Is an Effective Option in Massive Irreparable Rotator Cuff Tears: Minimum 2-Year Follow-Up

PURPOSE

The purpose of this study was to evaluate clinical and radiologic outcomes of arthroscopic superior capsular reconstruction (ASCR) with fascia lata autograft in patients with irreparable rotator cuff tears (IRCTs) performed using a single lateral-row fixation technique.

METHODS

We studied a retrospective case series of patients with large or massive IRCTs for ASCR with fascia lata autograft. Clinical outcomes were evaluated using the Visual Analog Scale (VAS) and the Constant score. Healing of the graft was assessed by magntic resonance imaging or ultrasound. Acromiohumeral distance was evaluated by radiographs.

RESULTS

Thirty-one patients with an average age of 61 years and an average follow-up of 35 months (24-51 months) underwent ASCR with fascia lata autograft. There was a significant improvement in VAS (7.7-0.7), Constant score (36.0-78.7), forward elevation (115°-171°), external rotation (33°-50°), strength (0.3 kg-2.3 kg), and acromiohumeral distance (6.1 mm-8.6 mm) (P < 0.001). Graft failure was present in 13.8% of patients, as shown by magnetic resonance imaging (26 patients) or ultrasound (3 patients). Patients with failed ASCR showed worse Constant scores (68.5.8 vs 80.2, P = 0.007), worse VAS (2.5 vs 0.4, P = 0.00002), worse external rotation (20° vs 54°, P = 0.004), lower acromiohumeral distance (5mm vs 9mm, P = 0.007), and a high association with the presence of os acromiale (χ²P = 0.003). No revision or subsequent surgical procedures were required.

CONCLUSIONS

ASCR, with autologous fascia lata and single lateral row configuration, is an effective option in irreparable rotator cuff tears and results in clinical and radiologic improvement.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

CT-based volumetric assessment of rotator cuff muscle in shoulder arthroplasty preoperative planning

Aims

The aim of this study was to describe a quantitative 3D CT method to measure rotator cuff muscle volume, atrophy, and balance in healthy controls and in three pathological shoulder cohorts.

Methods

In all, 102 CT scans were included in the analysis: 46 healthy, 21 cuff tear arthropathy (CTA), 18 irreparable rotator cuff tear (IRCT), and 17 primary osteoarthritis (OA). The four rotator cuff muscles were manually segmented and their volume, including intramuscular fat, was calculated. The normalized volume (NV) of each muscle was calculated by dividing muscle volume to the patient’s scapular bone volume. Muscle volume and percentage of muscle atrophy were compared between muscles and between cohorts.

Results

Rotator cuff muscle volume was significantly decreased in patients with OA, CTA, and IRCT compared to healthy patients (p < 0.0001). Atrophy was comparable for all muscles between CTA, IRCT, and OA patients, except for the supraspinatus, which was significantly more atrophied in CTA and IRCT (p = 0.002). In healthy shoulders, the anterior cuff represented 45% of the entire cuff, while the posterior cuff represented 40%. A similar partition between anterior and posterior cuff was also found in both CTA and IRCT patients. However, in OA patients, the relative volume of the anterior (42%) and posterior cuff (45%) were similar.

Conclusion

This study shows that rotator cuff muscle volume is significantly decreased in patients with OA, CTA, or IRCT compared to healthy patients, but that only minimal differences can be observed between the different pathological groups. This suggests that the influence of rotator cuff muscle volume and atrophy (including intramuscular fat) as an independent factor of outcome may be overestimated.

Cite this article: Bone Jt Open 2021;2(7):552–561.

Deep-learning framework and computer assisted fatty infiltration analysis for the supraspinatus muscle in MRI

Occupation ratio and fatty infiltration are important parameters for evaluating patients with rotator cuff tears. We analyzed the occupation ratio using a deep-learning framework and studied the fatty infiltration of the supraspinatus muscle using an automated region-based Otsu thresholding technique. To calculate the amount of fatty infiltration of the supraspinatus muscle using an automated region-based Otsu thresholding technique. The mean Dice similarity coefficient, accuracy, sensitivity, specificity, and relative area difference for the segmented lesion, measuring the similarity of clinician assessment and that of a deep neural network, were 0.97, 99.84, 96.89, 99.92, and 0.07, respectively, for the supraspinatus fossa and 0.94, 99.89, 93.34, 99.95, and 2.03, respectively, for the supraspinatus muscle. The fatty infiltration measure using the Otsu thresholding method significantly differed among the Goutallier grades (Grade 0; 0.06, Grade 1; 4.68, Grade 2; 20.10, Grade 3; 42.86, Grade 4; 55.79, p < 0.0001). The occupation ratio and fatty infiltration using Otsu thresholding demonstrated a moderate negative correlation (ρ = - 0.75, p < 0.0001). This study included 240 randomly selected patients who underwent shoulder magnetic resonance imaging (MRI) from January 2015 to December 2016. We used a fully convolutional deep-learning algorithm to quantitatively detect the fossa and muscle regions by measuring the occupation ratio of the supraspinatus muscle. Fatty infiltration was objectively evaluated using the Otsu thresholding method. The proposed convolutional neural network exhibited fast and accurate segmentation of the supraspinatus muscle and fossa from shoulder MRI, allowing automatic calculation of the occupation ratio. Quantitative evaluation using a modified Otsu thresholding method can be used to calculate the proportion of fatty infiltration in the supraspinatus muscle. We expect that this will improve the efficiency and objectivity of diagnoses by quantifying the index used for shoulder MRI.

Good outcome after repair of trauma-related anterosuperior rotator cuff tears-a prospective cohort study

BACKGROUND

Anterosuperior rotator cuff tears with a displaced long head of the biceps tendon are most often trauma-related, and patients with these conditions often present with severe pain and shoulder dysfunction. Repair of the subscapularis and supraspinatus and a biceps tenodesis or a tenotomy are the recommended treatments based on retrospective studies. The aim of this study was to prospectively evaluate clinical and structural treatment outcome in a cohort of trauma-related anterosuperior injuries in patients with previously healthy shoulders.

MATERIALS AND METHODS

Patients seeking care for a suspected rotator cuff injury after shoulder trauma were screened according to a protocol including clinical examination, baseline scoring with Western Ontario Rotator Cuff Index (WORC) and numeric rating scale of pain, ultrasound, and magnetic resonance imaging (MRI). Those with anterosuperior injuries were offered surgical treatment, structured postoperative physiotherapy, and inclusion in the present study with 1-year follow-up, including MRI, baseline scores, Constant-Murley score, and Patient Global Impression of Change. Thirty-three patients (78% men) with a mean age of 59 (40-76) years were included.

RESULTS

All patients had a biceps pulley lesion, a displaced biceps tendon, and incomplete full-thickness subscapularis and supraspinatus tears. Six patients declined surgery. At follow-up, the operated patients reached a median WORC score of 86% and a median change from baseline to follow-up of 50% (P = .0001). Pain decreased (P = .0001) at rest, at night, and during activity. The median Constant-Murley score was 86% of the contralateral nonoperated shoulder, 58% of the contralateral abduction strength recovered after surgery, and 86% reported that they were recovered or much improved. All repairs and tenodeses healed except for 2 supraspinatus tendons. The 6 nonoperated patients reached a median WORC score of 90, a change in the median value from baseline to follow-up of 31, but reported more pain, and a smaller proportion considered themselves as recovered or much improved. In all patients, the 1-year MRIs had signal changes in the upper muscular portion of subscapularis, consistent with fatty infiltration, regardless of operative or nonoperative treatment.

CONCLUSION

Anterosuperior rotator cuff injury with an associated pulley lesion and displaced long head of the biceps tendon may be treated successfully with surgery as the majority of patients in our cohort clinically recovered or were much improved without pain after a year. With a 1-year perspective, nonoperatively treated patients may also reach a reasonable clinical outcome. Independently of treatment or tendon healing, residual subscapularis muscle injury was seen, which may have long-term implications.

Comparison of tear characteristics, outcome parameters and healing in traumatic and non-traumatic rotator cuff tear: a prospective cohort study

PURPOSE

Acute traumatic and chronic non-traumatic rotator cuff tears are etiologically distinguishable entities. However, prospective studies comparing tear characteristics and outcomes between these two types of tears are lacking. The purpose of this study was to compare the tear characteristics, clinical and functional outcomes, and tendon healing as assessed on magnetic resonance imaging (MRI), between traumatic and non-traumatic rotator cuff tears.

METHODS

MRI proven rotator cuff tears were allocated into two groups according to the history of injury: Group 1 included 28 patients with traumatic tears and group 2 included 33 patients of non-traumatic cuff tears. Both the groups were compared for preoperative tear characteristics (tear size, muscle atrophy, fatty degeneration), range of motion, strength of shoulder abduction and external rotation, functional outcomes, and tendon integrity on MRI, 2 years after the surgery.

RESULTS

Postoperative mean active range of abduction (p = 0.005), abduction strength (p = 0.013), external rotation strength (p = 0.027), University of California at Los Angeles score (p < 0.001), Constant score (p = 0.002), American Shoulder and Elbow Surgeons scores (p = 0.028) and visual analog scale for pain (p = 0.02) were significantly better in group 1 as compared to group 2. The postoperative structural integrity of the cuff on MRI was better in group 1 as compared to group 2, but the values did not reach statistical significance (p = 0.13).

CONCLUSION

Findings from this study suggest that traumatic tears affect younger patients and while having a larger tear size, they have lesser muscle atrophy, fatty degeneration, and tendon retraction. Functional outcomes are better after treatment of traumatic tears as compared to non-traumatic tears. Chronicity of the tear and tendon retraction negatively affected healing in traumatic cuff tears. Muscle atrophy was found to be associated with poorer healing in non-traumatic tears. However, tear size was not associated with healing.

LEVEL OF EVIDENCE

II, Prospective cohort study.

Predicting the surgical reparability of large-to-massive rotator cuff tears by B-mode ultrasonography: a cross-sectional study

PURPOSE

This study aimed to compare the ability of B-mode ultrasonography and magnetic resonance imaging (MRI) to predict the repairability of large-to-massive rotator cuff tears (RCTs).

METHODS

This cross-sectional study included participants with large-to-massive RCTs who underwent arthroscopic repair. B-mode ultrasonography and MRI were conducted prior to arthroscopic repair. B-mode ultrasonography was used to evaluate the echogenicity of the rotator cuff muscle using the Heckmatt scale. Intra-rater and inter-rater reliabilities were examined for two independent physicians. MRI was used to evaluate the degrees of tendon retraction, fatty infiltration of rotator cuff muscles, and muscle atrophy. Finally, two experienced orthopedic surgeons performed surgery and decided whether the torn stump could be completely repaired intraoperatively.

RESULTS

Fifty participants were included, and 32 complete repairs and 18 partial repairs were performed. B-mode ultrasonography showed good intra-rater reliability and inter-rater reliability for assessment of the muscle echogenicity of the supraspinatus and infraspinatus muscles. The correlation coefficients between B-mode ultrasound findings and MRI findings showed medium to large effect sizes (r=0.4-0.8). The Goutallier classification of the infraspinatus muscles was the MRI predictor with the best discriminative power for surgical reparability (area under the curve [AUC], 0.89; 95% confidence interval [CI], 0.81 to 0.98), while the Heckmatt scale for infraspinatus muscles was the most accurate ultrasound predictor (AUC, 0.85; 95% CI, 0.74 to 0.96). No significant differences in AUCs among the MRI and ultrasound predictors were found.

CONCLUSION

B-mode ultrasonography was a reliable examination tool and had a similar ability to predict surgical reparability to that of MRI among patients with large-to-massive RCTs.

Swiss-wide multicentre evaluation and prediction of core outcomes in arthroscopic rotator cuff repair: protocol for the ARCR_Pred cohort study

INTRODUCTION

In the field of arthroscopic rotator cuff repair (ARCR), reporting standards of published studies differ dramatically, notably concerning adverse events (AEs). In addition, prognostic studies are overall methodologically poor, based on small data sets and explore only limited numbers of influencing factors. We aim to develop prognostic models for individual ARCR patients, primarily for the patient-reported assessment of shoulder function (Oxford Shoulder Score (OSS)) and the occurrence of shoulder stiffness 6 months after surgery. We also aim to evaluate the use of a consensus core event set (CES) for AEs and validate a severity classification for these events, considering the patient's perspective.

METHODS AND ANALYSIS

A cohort of 970 primary ARCR patients will be prospectively documented from several Swiss and German orthopaedic clinics up to 24 months postoperatively. Patient clinical examinations at 6 and 12 months will include shoulder range of motion and strength (Constant Score). Tendon repair integrity status will be assessed by ultrasound at 12 months. Patient-reported questionnaires at 6, 12 and 24 months will determine functional scores (subjective shoulder value, OSS), anxiety and depression scores, working status, sports activities, and quality of life (European Quality of Life 5 Dimensions 5 Level questionnaire). AEs will be documented according to a CES. Prognostic models will be developed using an internationally supported regression methodology. Multiple prognostic factors, including patient baseline demographics, psychological, socioeconomic and clinical factors, rotator cuff integrity, concomitant local findings, and (post)operative management factors, will be investigated.

ETHICS AND DISSEMINATION

This project contributes to the development of personalised risk predictions for supporting the surgical decision process in ARCR. The consensus CES may become an international reference for the reporting of complications in clinical studies and registries. Ethical approval was obtained on 1 April 2020 from the lead ethics committee (EKNZ, Basel, Switzerland; ID: 2019-02076). All participants will provide informed written consent before enrolment in the study.

TRIAL REGISTRATION NUMBER

NCT04321005.

PROTOCOL VERSION

Version 2 (13 December 2019).

Atrophy patterns in isolated subscapularis lesions

BACKGROUND

While supraspinatus atrophy can be described according to the system of Zanetti or Thomazeau there is still a lack of characterization of isolated subscapularis muscle atrophy. The aim of this study was to describe patterns of muscle atrophy following repair of isolated subscapularis (SSC) tendon.

METHODS

Forty-nine control shoulder MRI scans, without rotator cuff pathology, atrophy or fatty infiltration, were prospectively evaluated and subscapularis diameters as well as cross sectional areas (complete and upper half) were assessed in a standardized oblique sagittal plane. Calculation of the ratio between the upper half of the cross sectional area (CSA) and the total CSA was performed. Eleven MRI scans of patients with subscapularis atrophy following isolated subscapularis tendon tears were analysed and cross sectional area ratio (upper half /total) determined. To guarantee reliable measurement of the CSA and its ratio, bony landmarks were also defined. All parameters were statistically compared for inter-rater reliability, reproducibility and capacity to quantify subscapularis atrophy.

RESULTS

The mean age in the control group was 49.7 years (± 15.0). The mean cross sectional area (CSA) was 2367.0 mm² (± 741.4) for the complete subscapularis muscle and 1048.2 mm² (± 313.3) for the upper half, giving a mean ratio of 0.446 (± 0.046). In the subscapularis repair group the mean age was 56.7 years (± 9.3). With a mean cross sectional area of 1554.7 mm² (± 419.9) for the complete and of 422.9 mm² (± 173.6) for the upper half of the subscapularis muscle, giving a mean CSA ratio of 0.269 (± 0.065) which was seen to be significantly lower than that of the control group (p < 0.05).

CONCLUSION

Analysis of typical atrophy patterns of the subscapularis muscle demonstrates that the CSA ratio represents a reliable and reproducible assessment tool in quantifying subscapularis atrophy. We propose the classification of subscapularis atrophy as Stage I (mild atrophy) in case of reduction of the cross sectional area ratio < 0.4, Stage II (moderate atrophy) in case of < 0.35 and Stage III (severe atrophy) if < 0.3.

Predictors of clinical outcomes after non-operative management of symptomatic full-thickness rotator cuff tears

BACKGROUND

Previous studies have shown that non-surgical management can be an effective treatment strategy for many patients with rotator cuff tears. Despite the prevalence of rotator cuff disease, few studies have examined the patient and tear related factors that predict outcomes of nonsurgical management in this cohort of patients.

AIM

To identify factors that are associated with changes in patient reported outcomes over time in individuals with full-thickness rotator cuff tears treated without surgery.

METHODS

A cohort of 59 patients who underwent non-surgical management of full thickness rotator cuff tears with a minimum of 1-year follow-up were identified from our institutional registry. Patient demographics, comorbidities and tear characteristics were collected at initial presentation. Outcome measures were collected at baseline and at each clinical follow-up, which included Western Ontario Rotator Cuff (WORC) index, American Shoulder and Elbow Surgeons score, Visual Analog Scale for pain and Single Assessment Numerical Evaluation. Multi- and univariate regression analyses were used to determine the impact of each patient and tear related variable on final WORC scores and change in WORC scores throughout the study.

RESULTS

In this non-surgical cohort, all patient-reported outcome measures significantly improved compared to baseline at 1 and 2-year follow-up. There was no significant difference in outcomes between 1 and 2 years. The average improvement surpassed the published minimal clinically important differences values for WORC, American Shoulder and Elbow Surgeons, Visual Analog Scale pain and Single Assessment Numerical Evaluation scores. Regression analysis identified female gender (β = - 19.88, P = 0.003), smoking (β = -29.98, P = 0.014) and significant subscapularis fatty infiltration (β = -15.35, P = 0.024) as predictors of less favorable WORC scores at 1 year, and female gender (β = -19.09, P = 0.015) alone as a predictor of lower WORC scores at 2 years. Patients with symptom duration greater than 1 year at presentation reported less improvement in WORC scores at 1-year follow-up (β = -14.63, P = 0.052) and patients with traumatic tears reported greater improvements in WORC scores at 2-year follow-up (β = 17.37, P = 0.031).

CONCLUSION

Patients with full thickness rotator cuff tears can achieve and maintain clinically meaningful benefit from non-surgical management through 2-year follow-up. Female patients, smokers, and those with significant subscapularis fatty infiltration tend to have lower overall WORC scores at 1-year follow-up, and females also have lower WORC scores at 2-year follow-up. Patients presenting with symptoms greater than 1 year had less clinical improvement at 1-year follow-up, and those with traumatic tears had greater clinical improvement at 2-year follow-up.

Poor Prognostic Factors in Patients With Rotator Cuff Retear

Background:

The treatment for retears after arthroscopic rotator cuff repair (ARCR) has long been a challenge.

Purpose:

This study aimed to (1) summarize the characteristics of patients with a retear after primary ARCR and (2) determine the risk factors for poor clinical outcomes after a retear.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

We collected the data of patients with a retear after primary ARCR between January 2011 and December 2016. There were 45 patients with retears included (19 men [42.2%] and 26 women [57.8%]; mean ± SD age, 63.11 ± 8.87 years). Initially, the demographic and outcome data of patients with a retear were analyzed. Patients were classified into good and poor outcome groups according to their overall satisfaction at final follow-up. Univariable and multivariable logistic regression analyses were performed to determine the factors for poor clinical outcomes after a retear.

Results:

A total of 31 patients were classified into the good outcome group, and 14 patients were classified into the poor outcome group. Both the good and the poor outcome groups showed that clinical scores significantly improved at the time of the retear diagnosis, but the final scores were maintained or worse compared with scores at the time of the retear diagnosis. Final range of motion (ROM), except external rotation in the good outcome group, was worse or had no significant change compared with ROM at the time of the retear diagnosis. On multivariable logistic regression analysis, current smoking (odds ratio [OR], 45.580 [95% CI, 3.014-689.274]; P = .006), female sex (OR, 32.774 [95% CI, 2.433-441.575]; P = .009), and retears of the same or larger size than the initial tear (OR, 10.261 [95% CI, 1.544-68.202]; P = .016) showed a higher OR for poor clinical outcomes after a retear.

Conclusion:

Smoking, female sex, and retears of the same or larger size than the initial tear were independent risk factors for poor clinical outcomes after a rotator cuff retear. Final clinical scores and ROM were similar or worse compared with the scores and ROM at the time of the retear diagnosis. Therefore, revision surgery should be actively considered in female patients or those who smoke with poor clinical outcomes and a larger retear size than the preoperative tear size at the time of the retear diagnosis.

Deep learning method for segmentation of rotator cuff muscles on MR images

OBJECTIVE

To develop and validate a deep convolutional neural network (CNN) method capable of (1) selecting a specific shoulder sagittal MR image (Y-view) and (2) automatically segmenting rotator cuff (RC) muscles on a Y-view. We hypothesized a CNN approach can accurately perform both tasks compared with manual reference standards.

MATERIAL AND METHODS

We created 2 models: model A for Y-view selection and model B for muscle segmentation. For model A, we manually selected shoulder sagittal T1 Y-views from 258 cases as ground truth to train a classification CNN (Keras/Tensorflow, Inception v3, 16 batch, 100 epochs, dropout 0.2, learning rate 0.001, RMSprop). A top-3 success rate evaluated model A on 100 internal and 50 external test cases. For model B, we manually segmented subscapularis, supraspinatus, and infraspinatus/teres minor on 1048 sagittal T1 Y-views. After histogram equalization and data augmentation, the model was trained from scratch (U-Net, 8 batch, 50 epochs, dropout 0.25, learning rate 0.0001, softmax). Dice (F1) score determined segmentation accuracy on 105 internal and 50 external test images.

RESULTS

Model A showed top-3 accuracy > 98% to select an appropriate Y-view. Model B produced accurate RC muscle segmentations with mean Dice scores > 0.93. Individual muscle Dice scores on internal/external datasets were as follows: subscapularis 0.96/0.93, supraspinatus 0.97/0.96, and infraspinatus/teres minor 0.97/0.95.

CONCLUSIONS

Our results show overall accurate Y-view selection and automated RC muscle segmentation using a combination of deep CNN algorithms.

Defining the proximity of the axillary nerve from defined anatomic landmarks: an in vivo magnetic resonance imaging study

BACKGROUND

The location of the axillary nerve in the shoulder makes it vulnerable to traumatic or iatrogenic injury. Cadaveric studies have reported the location of the axillary nerve but are limited because of tissue compression, dehydration, and decay. Three-Tesla (T) magnetic resonance imaging (MRI) allows high anatomic resolution of neural structures. The aim of our study was to better define the location of the axillary nerve from defined bony surgical landmarks in vivo, using MRI scan.

METHODS

Using MRI, we defined a number of anatomic points and measured the distance from these to the perineural fat surrounding the axillary nerve using simultaneous tracker lines on both images. Two observers were used.

RESULTS

A total of 187 consecutive 3-T MRI shoulder scans were included. Mean age was 57.9 years (range 18-86). The axillary nerve was located at a mean of 14.1 mm inferior from the bony glenoid at the anterior border, 11.9 mm from the midpoint, and 12.0 mm from the posterior border. There was a significant difference between distance at the anterior border and midpoint (P < .001), and between the anterior and posterior borders (P < .001). The axillary nerve was located at a mean of 12.6 mm medial to the humeral shaft at the anterior border, 9.9 mm at the midpoint, and 8.6 mm from the posterior border. There was a significant difference between distance at the anterior border and midpoint (P = .008) and between the anterior and posterior borders (P = .002). The mean distance of the axillary nerve from the anterolateral edge of the acromion was 53.3 mm (95% confidence interval [CI] 52.3, 54.2; range 33.9-76.3). The mean distance of the axillary nerve from the inferior edge of the capsule was 2.7 mm (95% CI 2.9, 3.1; range 0.3-9.9). There was a positive correlation between humeral head diameter and axillary nerve distance from the inferior glenoid (R² = 0.061, P < .001). There was a positive correlation between humeral head diameter and distance from the anterolateral edge of the acromion (R² = 0.140, P < .001).

CONCLUSION

Our study has defined the proximity of the axillary nerve from defined anatomic landmarks. The proximity of the axillary nerve to the inferior glenoid and medial humeral shaft changes as the axillary nerve passes from anterior to posterior. The distance of the axillary nerve from the anterolateral edge of the acromion remains relatively constant. Both sets of distances may be affected by humeral head size. The study has relevance to the shoulder surgeon when considering "safe zones" during arthroscopic or open surgery.

MARS MRI assessment of fatty degeneration of the gluteal muscles in patients with THA: reliability and accuracy of commonly used classification systems

INTRODUCTION

Fatty degeneration of the gluteal muscles on metal artefact reduction sequence (MARS) MRI has been shown to correlate with poor functional outcomes, particularly in patients with total hip arthroplasty (THA). Standardized, reliable classification systems that permit assessment of fatty gluteal infiltration are needed for clinical decision making. This study aimed to compare the reproducibility and accuracy of commonly used MRI classification systems for fatty gluteal atrophy in THA patients.

METHODS

MARS magnetic resonance images of 82 patients with unilateral THA were analysed by three independent trained observers. The readers evaluated fatty degeneration of the gluteus minimus, gluteus medius, and gluteus maximus according to 3 widely used classification systems: Goutallier, Quartile, and Bal and Lowe. Interobserver and intraobserver repeatability were determined using the weighted Kappa test. Quantitative evaluation of the proportion of intramuscular fat based on MR signal intensities was obtained and represented the gold standard.

RESULTS

Mean interobserver agreement for the Quartile classification system (0.93) was higher compared with Goutallier classification system (0.87) and the Bal and Lowe classification system (0.83; range 0.79-0.88; p = 0.04). Intraobserver repeatability was significantly higher for the Quartile classification system (weighted kappa 0.91, 0.89, 0.85) compared with the Bal and Lowe classification system (weighted kappa 0.83, 0.77, 0.75; p < 0.01) and Goutallier classification system (weighted kappa 0.83, 0.77, 0.75; p = 0.04). Agreement with the gold standard measurements was significantly higher in the Quartile classification system (0.88, 0.84, 0.81) compared with the Goutallier classification system (0.80, 0.77, 0.78; p = 0.02) and Bal and Lowe classification system (0.76, 0.74, 0.73; p < 0.01).

DISCUSSION

This study directly compared three clinically used MRI classification systems for fatty gluteal muscle atrophy in THA patients. Our findings demonstrate that although all three classification systems demonstrate good reproducibility and accuracy, the Quartile classification system is superior to the others in terms of intraobserver reliability and accuracy to quantify fatty gluteal degeneration in THA patients.

Short-term outcomes of arthroscopic partial repair vs. latissimus dorsi tendon transfer in patients with massive and partially repairable rotator cuff tears

BACKGROUND

There is limited evidence on clinical outcomes of arthroscopic partial repair (APR) and latissimus dorsi tendon transfer (LDTT) for posterosuperior massive rotator cuff tears (mRCTs). We aimed to compare clinical outcomes of APR and LDTT for partially repairable posterosuperior mRCTs and to determine whether outcomes differ among tears that involve the teres minor.

METHODS

We retrieved the records of 112 consecutive patients with mRCTs deemed partially repairable due to fatty infiltration (FI) stage ≥3 in one or more rotator cuff muscles. Of the tears, 12 involved the subscapularis, 32 were managed conservatively, 14 were treated by reverse shoulder arthroplasty, and 7 were treated by stand-alone biceps tenotomy. Of the remaining 47 shoulders, 26 underwent APR and 21 underwent LDTT. At a minimum of 12 months, we recorded complications, active forward elevation, external rotation, the Constant-Murley score, American Shoulder and Elbow Surgeons (ASES) score, Subjective Shoulder Value (SSV), and Simple Shoulder Test (SST) score.

RESULTS

No significant differences between the APR and LDTT groups were found in terms of follow-up (23.4 ± 3.5 months vs. 22.1 ± 4.1 months, P = .242), Constant-Murley score (64.8 ± 13.7 vs. 58.9 ± 20.0, P = .622), ASES score (78.3 ± 19.3 vs. 74.4 ± 14.5, P = .128), active forward elevation (158.1° ± 19.4° vs. 142.8° ± 49.1°, P = .698), or external rotation (33.3° ± 17.4° vs. 32.2° ± 20.9°, P = .752). By contrast, the APR group had a higher SSV (73.3 ± 17.5 vs. 59.5 ± 20.0, P = .010), and SST score (8.3 ± 2.4 vs. 6.4 ± 3.0, P = .024). Univariable analysis revealed that advanced FI of the teres minor compromised Constant-Murley scores (β = -25.8, P = .001) and tended to compromise ASES scores (β = -15.2, P = .062). Multivariable analysis corroborated that advanced FI of the teres minor compromised Constant-Murley scores (β = -26.9, P = .001) and tended to compromise ASES scores (β = -16.5, P = .058).

CONCLUSION

Both APR and LDTT granted similar early clinical outcomes for partially repairable posterosuperior mRCTs, regardless whether the teres minor was intact or torn. Advanced FI of the teres minor was the only independent factor associated with outcomes, as it significantly compromised Constant-Murley scores and tended to compromise ASES scores.

Arthroscopic Side-to-Side Repair of Massive Rotator Cuff Tears Maintains Adequate Functional Improvement at 12 to 14 Years' Follow-up

BACKGROUND

Rotator cuff tears are common shoulder injuries that often cause pain and loss of function. Nonanatomic side-to-side techniques facilitate repair by minimizing tensions within tendons to improve healing and optimize the thickness of sutured tissues.

PURPOSE/HYPOTHESIS

The purpose was to evaluate long-term clinical and radiographic outcomes of arthroscopic side-to-side repair of massive rotator cuff tears (mRCTs). The hypothesis was that, at a minimum follow-up of 12 years, arthroscopic side-to-side repair maintains clinically important improvements.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

The authors reviewed records of all patients who underwent arthroscopic repair of mRCTs over 2 consecutive years. A total of 30 adult patients met the eligibility criteria and underwent side-to-side repair. Patients were evaluated clinically using the Constant score (CS) and ultrasound to assess retears at 3 timepoints after surgery: 2 to 4 years, 5 to 7 years, and 12 to 14 years.

RESULTS

At first follow-up (3.2 ± 0.5 years), all 30 patients had clinical and ultrasound assessment, which revealed 13 retears (43%). At second follow-up (6.2 ± 0.5 years), all 30 patients had clinical and ultrasound assessment, which revealed 2 new retears (total 50%). At final follow-up (13.0 ± 0.7 years), only 21 patients had clinical assessment (1 died and 8 could not be reached), and only 19 patients had ultrasound assessment, which revealed 6 new retears (total 79%). Both absolute CS and age-/sex-adjusted CS improved significantly from baseline values at first follow-up (73.5 and 96.6, respectively), and remained stable at second follow-up (69.0 and 91.9, respectively), and final follow-up (64.4 and 87.0, respectively). Compared to shoulders with intact repairs, those with retears tended to have lower absolute CS at all follow-up visits, although differences were not statistically significant.

CONCLUSION

Patients with mRCTs maintain satisfactory clinical scores at 12 to 14 years after arthroscopic side-to-side repair despite a high incidence of retears. Repair is a safe and effective treatment for mRCTs, providing a less invasive and less complex alternative to reverse shoulder arthroplasty and tendon transfer procedures.

Mid- to long-term outcomes after reverse shoulder arthroplasty with latissimus dorsi and teres major transfer for irreparable posterosuperior rotator cuff tears

AIM

The objective of this study was to describe the outcome of reverse shoulder arthroplasty (RSA) combined with modified L'Episcopo procedure at long-term follow-up (5 to 12 years).

METHODS

A retrospective review of 17 RSAs (mean age 67.2 years) with the modified L'Episcopo procedure conducted between 2006 and 2016 was performed. All patients had a combined loss of active elevation and external rotation with an irreparable posterosuperior rotator cuff tear. Clinical assessment was performed with a minimum follow-up of five years (mean 97.3 months). Outcome measures included range of motion, subjective shoulder value (SSV), visual analogue scale (VAS), and Constant-Murley scores.

RESULTS

All patients (16) demonstrated a significant improvement in all clinical and functional parameters. VAS pain scores improved from 6 ± 2.6 to 1 ± 1; SSV improved from 35 ± 14 to 72 ± 10; active forward elevation increased from 66° ± 34 to 125° ± 29; and active external rotation arm at the body increased from -11° ± 22 to 21° ±11 and in 90° of abduction from -10° ± 17 to 37° ± 24. The mean Constant score improved from 25 ± 11 to 59 ± 8. Active internal rotation did not significantly change (p = 0.332).

CONCLUSION

At long-term follow-up, RSA combined with modified L'Episcopo procedure resulted in significant improvements in pain, range of motion, and functional scores for patients with shoulder pseudoparalysis and a lack of active external rotation caused by a massive posterosuperior cuff tear with a teres minor deficiency.

Ultrasound shear wave elastography and its association with rotator cuff tear characteristics

Background

Approximately 20-60% of rotator cuff repairs fail with higher failure rates in patients with larger or more chronic tears. Although MRI provides an objective estimate of tear size, it can only provide qualitative descriptions of tear chronicity. By contrast, ultrasound shear wave elastography (SWE) may assess tear chronicity by estimating tissue mechanical properties (ie, shear modulus). Furthermore, SWE imaging does not share many of the challenges associated with MRI (eg, high cost, risk of claustrophobia). Therefore, the objective of this study was to determine the extent to which estimated supraspinatus shear modulus is associated with conventional MRI-based measures of rotator cuff tear size and chronicity.

Methods

Shear modulus was estimated using ultrasound SWE in two regions of the supraspinatus (intramuscular tendon, muscle belly) under two contractile conditions (passive, active) in 22 participants with full-thickness rotator cuff tears. The extent to which estimated supraspinatus shear modulus is associated with conventional MRI measures of tear size and chronicity was assessed using correlation coefficients and Kruskal-Wallis tests, as appropriate.

Results

Estimated shear modulus was not significantly associated with anterior/posterior tear size (P > .09), tear retraction (P > .20), occupation ratio (P > .11), or fatty infiltration (P > .30) under any testing condition.

Discussion

Although ultrasound SWE measurements have been shown to be altered in the presence of various tendinopathies, the findings of this study suggest the utility of ultrasound SWE in this population (ie, patients with a small to medium supraspinatus rotator cuff tear) before surgical rotator cuff repair remains unclear.

Machine Learning Can Predict Level of Improvement in Shoulder Arthroplasty

The ability to accurately predict postoperative outcomes is of considerable interest in the field of orthopaedic surgery. Machine learning has been used as a form of predictive modeling in multiple health-care settings. The purpose of the current study was to determine whether machine learning algorithms using preoperative data can predict improvement in American Shoulder and Elbow Surgeons (ASES) scores for patients with glenohumeral osteoarthritis (OA) at a minimum of 2 years after shoulder arthroplasty.

METHODS

This was a retrospective cohort study that included 472 patients (472 shoulders) diagnosed with primary glenohumeral OA (mean age, 68 years; 56% male) treated with shoulder arthroplasty (431 anatomic total shoulder arthroplasty and 41 reverse total shoulder arthroplasty). Preoperative computed tomography (CT) scans were used to classify patients on the basis of glenoid and rotator cuff morphology. Preoperative and final postoperative ASES scores were used to assess the level of improvement. Patients were separated into 3 improvement ranges of approximately equal size. Machine learning methods that related patterns of these variables to outcome ranges were employed. Three modeling approaches were compared: a model with the use of all baseline variables (Model 1), a model omitting morphological variables (Model 2), and a model omitting ASES variables (Model 3).

RESULTS

Improvement ranges of ≤28 points (class A), 29 to 55 points (class B), and >55 points (class C) were established. Using all follow-up time intervals, Model 1 gave the most accurate predictions, with probability values of 0.94, 0.95, and 0.94 for classes A, B, and C, respectively. This was followed by Model 2 (0.93, 0.80, and 0.73) and Model 3 (0.77, 0.72, and 0.71).

CONCLUSIONS

Machine learning can accurately predict the level of improvement after shoulder arthroplasty for glenohumeral OA. This may allow physicians to improve patient satisfaction by better managing expectations. These predictions were most accurate when latent variables were combined with morphological variables, suggesting that both patients' perceptions and structural pathology are critical to optimizing outcomes in shoulder arthroplasty.

LEVEL OF EVIDENCE

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

The 50 Highest Cited Papers on Rotator Cuff Tear

PURPOSE

The purpose of this study was to determine the 50 most cited articles on rotator cuff tear and their characteristics.

METHODS

Thomson ISI Web of Science was searched for the following search terms "rotator cuff" and "tear." The following characteristics were determined for each article: author(s), year of publication, source journal, geographic origin, article type (and subtype), and level of evidence for clinical articles.

RESULTS

The number of citations ranged from 1558 to 253. The 50 most often cited articles were published in 7 journals. The majority of the articles (n = 46) were clinical, with the remaining representing some type of basic science research. Among clinical articles, the case series (n = 23) was the most common article subtype. Nine articles were methodologic in that they proposed a new classification/scoring system or technique. The most common level of evidence was Level IV (n = 31).

CONCLUSION

This article provides clinicians, researchers, and trainees with a group of articles that should be taken into consideration as building blocks in the treatment of rotator cuff tears.

LEVEL OF EVIDENCE

Level IV, literature review.

New quantified measurement of fatty infiltration of the rotator cuff muscles using magnetic resonance imaging

BACKGROUND

The degree of fatty infiltration of the rotator cuff muscle is typically evaluated using the Goutallier-Fuchs grading system, but its consistency remains controversial. This study aimed to evaluate a new quantified measurement of fatty infiltration based on three-dimensionally reconstructed volumetric data obtained from magnetic resonance images of non-pathologic shoulders using open-source software.

METHODS

Fourteen shoulder 3-T magnetic resonance images (8 men, 6 women) without lesions obtained between 2010 and 2017 were analysed. Slicer version 4.6.2 was used to semi-automatically reconstruct the three-dimensional volumetric data from T2 sagittal oblique images and to differentiate fat tissue from rotator cuff muscle using the difference in signal intensity.

RESULTS

The cutoff value for dividing muscle and fat was 508.9. The inter-class and intra-class correlations of each rotator cuff muscle and fat tissue were >0.9 (all P < 0.001). The mean muscle volume of the supraspinatus, infraspinatus, teres minor, and subscapularis were 15.2, 20.9, 13.3, and 29.7 mL, respectively. The muscle volume of the men was greater than that of the women (all P < 0.001), and the fat infiltration ratio was positively correlated with body mass index (all P < 0.05).

CONCLUSIONS

The semi-automated quantified measurement of fatty infiltration of the rotator cuff muscles using magnetic resonance imaging and Slicer software presented excellent consistency. This technique could be an alternative measurement to complement the weak consistency of the Goutallier-Fuchs grading system. However, to reduce the error of measurement, this study evaluated non-pathologic shoulders. Therefore, further study using magnetic resonance imaging of pathologic shoulders is necessary for actual clinical application.

LEVEL OF EVIDENCE

Level IV, case series, diagnostic study.

Assessment of Tendon Retraction in Large to Massive Rotator Cuff Tears: A Modified Patte Classification Based on 2 Coronal Sections on Preoperative Magnetic Resonance Imaging With Higher Specificity on Predicting Reparability

PURPOSE

To propose a modified Patte classification (evaluating tendon retraction on 2 coronal sections) and analyze whether this classification was better at predicting irreparability and retear of large to massive rotator cuff tears (RCTs).

METHODS

A retrospective study was performed. Imaging evaluation including tendon retraction, fatty infiltration, the acromiohumeral distance (AHD), and the tangent sign was performed using magnetic resonance imaging. The modified Patte classification was used to assess tendon retraction. Intraobserver and interobserver reliability was analyzed by calculating intraclass correlation coefficients. Factors affecting irreparability and retear were analyzed using both univariate and multivariate analyses. Sensitivity and specificity of tendon retraction to predict irreparability and retear were calculated.

RESULTS

A total of 121 shoulders with large to massive RCTs underwent arthroscopic rotator cuff repairs. The modified Patte classification system had excellent interobserver and intraobserver reliability. Several factors were associated with reparability and retear in the univariate analysis. However, in binary logistic regression analysis, the only factors affecting reparability were AHD less than 0.4 cm (P = .007) and modified Patte stage III tendon retraction (P = .023). Low-grade repair quality (P = .001) and modified Patte stage III tendon retraction (P = .031) were independent factors for retear. Modified Patte stage III had a high specificity for predicting irreparability (93.58%) and retear (98.78%), whereas the specificity of original Patte stage III was 76.15% and 84.15%, respectively.

CONCLUSIONS

For large to massive RCT repairs, modified Patte stage III tendon retraction with evaluation of 2 coronal cuts reveals higher specificity on predicting tendon irreparability and postoperative retear. An AHD less than 0.4 cm on magnetic resonance imaging and modified Patte stage III tendon retraction were independent risk factors for irreparability. Low-grade repair quality and modified Patte stage III tendon retraction were independent risk factors for postoperative retear.

LEVEL OF EVIDENCE

Level III, case-control study.

Comparison of Structural Subscapularis Integrity After Latarjet Procedure Versus Iliac Crest Bone Graft Transfer

Background:

Although clinical outcome scores are comparable after coracoid transfer procedure (Latarjet) and iliac crest bone graft transfer (ICBGT) for anterior shoulder instability with glenoid bone loss, a significant decrease in internal rotation capacity has been reported for the Latarjet procedure.

Hypothesis:

The subscapularis (SSC) musculotendinous integrity will be less compromised by ICBGT than by the Latarjet procedure.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

We retrospectively analyzed pre- and postoperative computed tomography (CT) scans at short-term follow-up of 52 patients (26 Latarjet, 26 ICBGT) previously assessed in a prospective randomized controlled trial. Measurements included the preoperative glenoid defect area and graft area protruding the glenoid rim at follow-up and tendon thickness assessed through SSC and infraspinatus (ISP) ratios. Fatty muscle infiltration was graded according to Goutallier, quantified with muscle attenuation in Hounsfield units, and additionally calculated as percentages. We measured 3 angles to describe rerouting of the SSC musculotendinous unit around the bone grafts.

Results:

SSC fatty muscle infiltration was 2.0% ± 2.2% in the Latarjet group versus 2.4% ± 2.2% in ICBGT (P = .546) preoperatively and showed significantly higher values in the Latarjet group at follow-up (5.3% ± 4.5% vs 2.3% ± 1.7%; P = .001). In total, 4 patients (15.4%) in the Latarjet group showed a progression from grade 0 to grade 1 at follow-up, whereas no changes in the ICBGT group were noted. The measured rerouting angle of the SSC muscle was significantly increased in the Latarjet group (11.8° ± 2.1°) compared with ICBGT (7.5° ± 1.3°; P < .001) at follow-up, with a significant positive correlation between this angle and fatty muscle infiltration (R = 0.447; P = .008). Ratios of SSC/ISP tendon thickness were 1.03 ± 0.3 in the Latarjet group versus 0.97 ± 0.3 (P = .383) in ICBGT preoperatively and showed significantly lower ratios in the Latarjet group (0.7 ± 0.3 vs 1.0 ± 0.2; P < .001) at follow-up.

Conclusion:

Although clinical outcome scores after anterior shoulder stabilization with a Latarjet procedure and ICBGT are comparable, this study shows that the described decline in internal rotation capacity after Latarjet procedure has a radiographic structural correlate in terms of marked thinning and rerouting of the SSC tendon as well as slight fatty degeneration of the muscle.

Magnetic resonance imaging of the shoulder

The aim of this article is to review the use of magnetic resonance imaging (MRI) for the evaluation of shoulder pain, which is a common clinical complaint of the musculoskeletal system. MRI is an essential auxiliary tool to evaluate these patients because of its high resolution and high sensitivity in depicting the soft tissues. This article will review the imaging technique, normal imaging anatomy, and most common imaging findings of disorders of tendons, labrum, and ligaments of the shoulder. It will also discuss common systemic diseases that manifest in the shoulder as well as disorders of the acromioclavicular joint and bursae. New advances and research in MRI have provided additional potential uses for evaluating shoulder derangements.

How periarticular corticosteroid injections impact the integrity of arthroscopic rotator cuff repair

INTRODUCTION

Multimodal analgesic (MMA) injections combined with corticosteroids have recently been shown to be effective for managing pain after arthroscopic rotator cuff repair.

HYPOTHESIS

The goal of this study was to analyze the effects of corticosteroid injections on the integrity of tendon repairs using magnetic resonance imaging (MRI). The hypothesis was that MMA injections combined with corticosteroids have no deleterious effects on functional outcomes and tendon healing 1 year after surgical rotator cuff repair.

METHODS

This was a prospective, double-blind study of 50 patients undergoing arthroscopic rotator cuff repair who were randomized into two groups. The study group (n=25) received a periarticular injection of a mixture of ropivacaine, morphine and methylprednisolone at the end of the procedure. The control group (n=25) received a placebo injection. The clinical outcomes were the pain level and complications, while the functional outcomes consisted of the Constant-Murley Score (CMS), American Shoulder and Elbow Surgeons Shoulder (ASES) score and Simple Shoulder Test (SST). The structural integrity of the operated tendons was analyzed on MRI at a mean follow-up of 15.1±1.3 months for the study group and 15.2±1.1 for the control group (p=0.848).

RESULTS

Pain on a visual analog scale was significantly reduced in both groups after the surgery. Nevertheless, there was no significant difference between groups at the final follow-up visit (p=0.803). Compared to the preoperative values, the CMS, ASES and SST significantly improved in both groups after surgery but were not significantly different between groups at the final assessment (p=0.801, 0.869 and 0.769, respectively). MRI revealed supraspinatus tendon retears in 16% of patients in the study group and 36% in the control group (p=0.107). There were no infections in the study group as of the final assessment. Advanced age (p=0.049), diabetes (p<0.01) and posterior extension of the tear (p=0.039) negatively impact healing. Corticosteroid injection did not negatively impact healing (p=0.197).

CONCLUSION

This study shows that MMA injection combined with corticosteroids does not alter the tendon healing, clinical outcomes, or functional outcomes 1 year after arthroscopic rotator cuff repair. It remains a safe and effective analgesia method during rotator cuff repair surgery.

LEVEL OF EVIDENCE

II, low-powered placebo-controlled, randomized study.

Comparison of shoulder muscle strength, cross-sectional area, acromiohumeral distance, and thickness of the supraspinatus tendon between symptomatic and asymptomatic patients with rotator cuff tears

BACKGROUND

The purpose of this study was to demonstrate the differences in shoulder muscle strength, cross-sectional area of the rotator cuff muscles, acromiohumeral distance, and supraspinatus tendon thickness between symptomatic and asymptomatic patients with rotator cuff tears.

METHODS

Thirty-two symptomatic patients and 23 asymptomatic patients with rotator cuff tears participated in this study. Data of the patients with any type of tear and supraspinatus tear were analyzed. We evaluated the isometric torque, cross-sectional area of the rotator cuff muscles, supraspinatus tendon thickness, acromiohumeral distance, range of motion, and Western Ontario Rotator Cuff Index.

RESULTS

Asymptomatic patients showed greater isometric torque of shoulder abduction and internal rotation than symptomatic patients with any type of tear (P ≤ .01). Asymptomatic patients also demonstrated greater cross-sectional area of the supraspinatus (P < .01); however, there was no significant difference in the cross-sectional area of the other cuff muscles. There was also no significant difference in the supraspinatus tendon thickness (P = .10). The acromiohumeral distance at 90° of shoulder abduction was larger (P = .04) in asymptomatic patients. Additionally, similar tendencies were observed in the results of patients with supraspinatus tears, except for the isometric torque of shoulder external rotation. This torque was greater (P < .01) in asymptomatic patients.

CONCLUSION

Asymptomatic patients showed greater shoulder range of motion, muscle strength of shoulder abduction and internal rotation, small occupation ratio of supraspinatus tendon thickness as a percentage of acromiohumeral distance, and large cross-sectional area of supraspinatus.