Is there a difference in the acromiohumeral distances measured on radiographic and magnetic resonance images of the same shoulder with a massive rotator cuff tear?

Investigating the reliability and validity of subacromial space measurements using ultrasound and MRI

BACKGROUND

While ultrasound (US) measures of the subacromial space (SAS) have demonstrated excellent reliability, measurements are typically captured by experts with extensive ultrasound experience. Further, the agreement between US measured SAS width and other imaging modalities has not been explored. This research evaluated the agreement between SAS measures captured by novice and expert raters and between US and magnetic resonance imaging (MRI). This study also evaluated the effect of US transducer tilt on measured SAS.

METHODS

Nine men and nine women participated in this study. US images were captured by a novice and expert with the participant in both seated and supine positions. An inclinometer was fixed to the US probe to measure transducer tilt. SAS width was measured in real time from freeze framed images. MRI images were captured, and the humerus and acromion manually segmented. The SAS width was measured using a custom algorithm.

RESULTS

Intraclass correlation coefficients (ICCs) between novice and expert raters were 0.74 and 0.63 for seated and supine positions, respectively. Intra-rater agreement was high for both novice (ICC = 0.83-0.84) and expert (ICC ≥ 0.94) raters. Agreement between US and MRI was poor (ICC = 0.21-0.49) but linearly related.

CONCLUSIONS

Moderate agreement between novice and expert raters was demonstrated, while the agreement between US and MRI was poor. High intra-rater reliability within each rater suggests that US measures of the SAS may be completed by a novice with introductory training.

The Effect of Acromioplasty Performed During Rotator Cuff Repairs on Clinical Outcomes in Patients With Type 3 Acromion: A Retrospective Study

OBJECTIVE

Rotator cuff (RC) tears often necessitate surgery, with acromioplasty being frequently performed alongside RC repair. However, the impact of acromioplasty on clinical outcomes remains a subject of discussion. The current study aimed to investigate the effect of acromioplasty during RC repair on clinical outcomes in patients with type 3 acromion.

MATERIALS AND METHODS

Eighty-five patients, who underwent RC repair between January 2016 and December 2020, were categorized into two groups: Group 1, comprising 40 patients without acromioplasty, and Group 2, including 45 patients who received acromioplasty. Subacromial distance (SAD) and clinical scores were assessed pre- and post-operatively.

RESULTS

Group 1, comprising 40 patients without acromioplasty, had an average age of 59.45±10.43 years. Among them, 27 (67.5%) were female. The mean symptom duration was 10.4±4.3 months, and the mean follow-up period was 16.2±1.9 months. Group 2, which underwent acromioplasty, included 45 patients with an average age of 56.49±8.97 years, with 30 (66.7%) of them being female. The mean symptom duration was 9.5±3.6 months, and the mean follow-up time was 15.78±2.17 months in this group. Group 2 showed a relatively greater improvement in SAD compared to Group 1. The evaluation of clinical outcomes did not reveal any significant differences between the groups.

CONCLUSION

Concomitant acromioplasty does not have a significant effect on clinical outcomes in patients undergoing arthroscopic RC repair.

Incongruity of the scapulohumeral arch: an indirect sign of posterior subluxation of the humeral head in primary glenohumeral osteoarthritis

BACKGROUND

In symptomatic glenohumeral osteoarthritis, arthroplasty is the gold standard to restore a mobile and painless shoulder. The kind of arthroplasty chosen is mainly based on the evaluation of the rotator cuff and the type of glenoid. The aim of this study was to analyze the scapulohumeral arch in primary glenohumeral osteoarthritis (PGHOA) with an uninjured cuff and to determine whether posterior humeral subluxation influences the Moloney line, which corresponds to an intact scapulohumeral arch.

MATERIALS AND METHODS

Between 2017 and 2020, 58 anatomic total shoulder arthroplasties were implanted in the same center. We included all patients with complete preoperative imaging (radiographs and magnetic resonance imaging or arthro-computed tomography scans) assessing an intact rotator cuff. A total of 55 shoulders that had undergone surgery with a total anatomic shoulder prosthesis were analyzed after determination of the type of glenoid in the frontal plane according to the Favard classification on an anteroposterior radiograph and in the axial plane according to the Walch classification on computed tomography scans. The grade of osteoarthritis was evaluated according to the Samilson classification. We analyzed whether there was a rupture of the Moloney line on the frontal radiograph and assessed the acromiohumeral distance.

RESULTS

After preoperative analysis of 55 shoulders, 24 shoulders had type A glenoids and 31 had type B glenoids. Scapulohumeral arch rupture was observed in 22 shoulders, and posterior subluxation of the humeral head was found in 31 shoulders, of which 25 had type B1 glenoids and 6 had type B2 glenoids according to the Walch classification. Most glenoids were type E0 (n = 47.85%). Incongruity of the Moloney line was more frequent in shoulders with type B glenoids (20 of 31 [65%]) than those with type A glenoids (2 of 24 [8%], P < .001). No patient with a type A1 glenoid (0 of 15) had a rupture of the Moloney line, and only 2 patients with a type A2 glenoid (2 of 9) had incongruity of the scapulohumeral arch.

CONCLUSION

In PGHOA, rupture of the scapulohumeral arch seen on anteroposterior radiographs, also known as the Moloney line, may be an indirect sign of posterior humeral subluxation, corresponding to a type B glenoid per the Walch classification. Incongruity of the Moloney line may indicate a rotator cuff injury or posterior glenohumeral subluxation with an intact cuff in PGHOA.

Validation of a novel 3-dimensional classification for degenerative arthritis of the shoulder

INTRODUCTION

A novel three-dimensional classification to comprehensively describe degenerative arthritis of the shoulder (DAS) was recently published by our group. The purpose of the present work was to investigate intra- and interobserver agreement as well as validity for the three-dimensional classification.

MATERIALS AND METHODS

Preoperative computed tomography (CT) scans of 100 patients who had undergone shoulder arthroplasty for DAS were randomly selected. Four observers independently classified the CT scans twice, with an interval of 4 weeks, after prior three-dimensional reconstruction of the scapula plane using a clinical image viewing software. Shoulders were classified according to biplanar humeroscapular alignment as posterior, centered or anterior (> 20% posterior, centered, > 5% anterior subluxation of humeral head radius) and superior, centered or inferior (> 5% inferior, centered, > 20% superior subluxation of humeral head radius). Glenoid erosion was graded 1-3. Gold-standard values based on precise measurements from the primary study were used for validity calculations. Observers timed themselves during classification. Cohen's weighted κ was employed for agreement analysis.

RESULTS

Intraobserver agreement was substantial (κ = 0.71). Interobserver agreement was moderate with a mean κ of 0.46. When the additional descriptors extra-posterior and extra-superior were included, agreement did not change substantially (κ = 0.44). When agreement for biplanar alignment alone was analyzed, κ was 0.55. The validity analysis reached moderate agreement (κ = 0.48). Observers took on average 2 min and 47 s (range 45 s to 4 min and 1 s) per CT for classification.

CONCLUSIONS

The three-dimensional classification for DAS is valid. Despite being more comprehensive, the classification shows intra- and interobserver agreement comparable to previously established classifications for DAS. Being quantifiable, this has potential for improvement with automated algorithm-based software analysis in the future. The classification can be applied in under 5 min and thus can be used in clinical practice.

The effect of biceps tenotomy on superior humeral migration in arthroscopic repaired full-thickness supraspinatus tears

Background

Lesions of the long head of the biceps (LHB) tendon are a prevalent injury that frequently coexists with rotator cuff injuries. This study aimed to assess the effect of supraspinatus (SST) repair with concurrent LHB tenotomy on superior migration of the humeral head. The acromiohumeral distance (AHD) was determined via ultrasound to evaluate the superior migration of the humeral head.

Methods

The study population was retrospectively recruited from patients who underwent unilateral arthroscopic repair of isolated degenerative full-thickness SST tears between January 2017 and December 2019. Patients were divided into 2 subgroups based on whether they underwent LHB tenotomies during arthroscopy. While 37 patients underwent arthroscopic single-row SST repair, the other 33 patients underwent arthroscopic single-row SST repair with LHB tenotomy. The subject group consisted of people who had undergone arthroscopic shoulder surgery. Contralateral shoulders without rotator cuff injuries were included in the control group. The AHD and SST thicknesses of patients were examined via the ultrasound in both groups and subgroups.

Results

The mean age in the SST repair group was 55.52 ± 4.58 years (range, 46-63 years), whereas it was 58.24 ± 3.98 (range, 52-73 years) in the SST repair + LHB tenotomy group. In the SST repair group, 57.6% of patients were female and 42.4% were male, whereas 56.8% and 43.2% were in the SST repair + LHB tenotomy group, respectively. The mean body mass index was 28.06 ± 1.31 kg/m2 (range, 25.7-31.2 kg/m2) in the SST repair group and 28.95 ± 1.79 kg/m2 in the SST repair + LHB tenotomy group. Groups were not different for sex, surgery side, dominant side, tear size, and follow-up time; however, the SST repair + LHB tenotomy group had significantly higher mean age and body mass index than the SST repaired group. The mean AHD value and SST thickness were significantly less in both the rotator cuff repair group and the rotator cuff repair + LHB tenotomy group compared to the healthy shoulder. The mean AHD value was significantly lower in the SST repaired + LHB tenotomy group than in the SST repair group (P = .02).

Conclusion

The AHD was narrowed in patients who underwent LHB tenotomy and radiologically demonstrated the depressor effect of the LHB tendon on the humeral head. As a secondary outcome, we demonstrated that regardless of tenotomy, AHD could not be restored in patients who underwent arthroscopic single-row SST repair.

Comparison of the Goutallier Classification of Fatty Infiltration for the Subscapularis With a Novel Modified Classification

Background

Fatty infiltration in the subscapularis muscle extends to the upper portion of the muscle first and then to the lower portion only after some degree of fatty change has taken place in the upper region. Although the Goutallier classification is the most widely used method to categorize fatty infiltration, how to accurately and reliably determine the extent of infiltration is controversial.

Purpose

To examine a modified classification that is more reliable in (1) assessing fatty infiltration of the subscapularis muscle and (2) predicting the structural integrity of the repaired tendon by identifying cutoff points for retear.

Study Design

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

Methods

This study retrospectively examined the records of 545 patients who underwent arthroscopic repair for a subscapularis tear. Two shoulder surgeons reviewed the preoperative magnetic resonance imaging scans of all enrolled patients and evaluated the fatty infiltration of the subscapularis muscle based on the original Goutallier classification, as well as a novel modified Goutallier classification designed to measure the proportion of fat and muscle in the upper and lower portions of the muscle separately. Intra- and interobserver agreement of the reviewers was calculated using κ statistics. Using receiver operating characteristic curve analysis, we determined the cutoff point for the particular fatty infiltration grade related to the occurrence of retear for each classification scheme.

Results

The κ values for interobserver reliability were 0.743 and 0.856 for the original and modified Goutallier classifications, respectively, with the modified classification having significantly higher reliability (Z = 4.064; P < .001). Cutoff points for the fatty infiltration grade associated with retear were 2.5 for the original Goutallier classification (sensitivity, 65.3%; specificity, 95.6%; accuracy, 87.8%) and 3.5 for the modified classification (sensitivity, 52.5%; specificity, 97.8%; accuracy, 89.7%).

Conclusion

In assessing fatty infiltration of the subscapularis muscle, the modified Goutallier classification showed higher reliability than the original Goutallier classification. The cutoff point for potential retear (grade 3.5) was at a point where the fatty infiltration extended to the lower portion of the subscapularis muscle.

Poly-l-lactide-co-ε-caprolactone (PLCL) and poly-l-lactic acid (PLLA)/gelatin electrospun subacromial spacer improves extracellular matrix (ECM) deposition for the potential treatment of irreparable rotator cuff tears

Biodegradable subacromial spacer implantation has become practicable for the treatment of irreparable rotator cuff tears (IRCT). However, the relative high degradation rate and inferior tissue regeneration properties of current subacromial spacer may lead to failure regards to long-term survival. It is reported that satisfactory clinical results lie in the surrounding extracellular matrix (ECM) deposition after implantation. This study aims to develop a biological subacromial spacer that would enhance tissue regeneration properties and results in better ECM deposition. Physicochemical properties were characterized on both poly-l-lactide-co-ε-caprolactone (PLCL) dip-coating spacer (monolayer spacer, MS) and PLCL dip-coating + Poly-l-Lactic Acid (PLLA)/Gelatin electrospun spacer (Bilayer Spacer, BS). Cytocompatibility, angiogenesis, and collagen inducibility were evaluated with tendon fibroblasts and endothelial cells. Ultrasonography and histomorphology were used to analyze biodegradability and surrounding ECM deposition after the implantation in vivo. BS was successfully fabricated with the dip-coating and electrospinning technique, based on the human humeral head data. In vitro studies demonstrated that BS showed a greater cytocompatibility, and increased secretion of ECM proteins comparing to MS. In vivo studies indicated that BS promoted ECM deposition and angiogenesis in the surrounding tissue. Our research highlights that BS exhibits better ECM deposition and reveals a potential candidate for the treatment of IRCT in future.

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.

Editorial Commentary: Dermal Grafts for Irreparable Rotator Cuff Tears-"Bridge Over Troubled Waters"

The treatment of an irreparable rotator cuff tear is an enigma. There are so many treatment options, with different experts recommending different treatments. These include physical therapy, partial repairs, tendon transfers such as the latissimus dorsi and the lower trapezius, biceps tenotomy, tissue augmentation with allografts or autografts, balloon spacers, and finally a reverse prosthesis. It is an easy decision when the patient is physiologically old with many medical comorbidities and arthritis. It is much more difficult when the patient is younger with no arthritis. Many patients with a failed massive cuff repair do well with a supervised therapy program despite the absence of 2 tendons (the supraspinatus and infraspinatus). Nothing works well when the subscapularis and/or teres minor are irreparable. I will usually try a 3-month physical therapy program, and if this is not successful in improving pain and function, consider surgery. If I can do an adequate partial repair, where the residual defect is small enough that the humeral head does not button hole through the defect like a boutonniere deformity, that is my treatment of choice. I will only do grafts with Hamada stage 1 or 2, as stage 3 with a fixed humeral head against the acromion do not do well. I am intrigued by the balloon spacer and why the results are still adequate, even when there is no balloon present after about 1 year. I'm holding judgment on that until there are more published studies. A reverse prosthesis I use as a last resort.

The differences of the acromiohumeral interval between supine and upright radiographs of the shoulder

The acromiohumeral interval (AHI) is a measurement used to determine the superior migration of the humeral head in rotator cuff (RC) tear patients. The purpose of this study was to compare the AHI of; supine, upright shoulder radiographs, and magnetic resonance imaging (MRI) of the shoulder. The 86 shoulders were divided into 3 groups that included; (1) non-full thickness tear (50%), (2) full thickness (FT) tear ≤3 cm (33.7%), and (3) FT tear > 3 cm (16.3%). The mean difference of AHI noted was significantly lower in the supine radiographs and MRIs than with the upright (1.34–1.37 mm, 1.62–1.87 mm, respectively). Upright AHI ≤ 7.0 mm had 27.9% sensitivity and 100% specificity in diagnosing FT tears with 64% accuracy (p < 0.001). The supine AHI ≤ 6.5 mm had 32.6% sensitivity, 100.0% specificity, and 66.3% accuracy (p < 0.01). The results revealed the AHI in supine radiographs were significantly lower than upright shoulder radiographs. For AHI ≤ 7 mm in upright shoulder radiographs, this remains as an appropriate diagnostic test for ruling in shoulders with full thickness rotator cuff tears. This value was not relevant for use as the cut point in the supine radiographs and MRIs.

Pseudoparalysis and Acromiohumeral Interval Reversibility Are the Most Important Factors Affecting the Achievement of Patient-Acceptable Symptom State After Arthroscopic-Assisted Latissimus Dorsi Tendon Transfer

PURPOSE

To determine the patient-acceptable symptom state (PASS) values for American Shoulder and Elbow Surgeons (ASES) score and the Constant-Murley (CM) score after arthroscopic-assisted latissimus dorsi tendon transfer (LDTT) and to identify potential factors affecting the achievement of PASS.

METHODS

Fifty consecutive patients who underwent arthroscopic-assisted LDTT between 2015 and 2020 were retrospectively analyzed. In total, 42 patients met the inclusion criteria with minimum follow-up of 1 year postoperative. Patients were evaluated preoperatively and 1-year postoperatively with multiple clinical measurements including ASES, CM, score and PASS. The primary outcome was identified as patient satisfaction which assessed with achievement of a PASS. Potential factors affecting the patient satisfaction including age, sex, body mass index, previous surgery, presence of pseudoparalysis, critical shoulder angle, shoulder abduction moment index, acromiohumeral interval (AHI) reversibility, Hamada grade and fatty infiltration were evaluated for their association with PASS value by stepwise logistic regression analysis.

RESULTS

A total of 42 patients were evaluated with mean follow-up 27.8 ± 8.21 months. The ASES and CM scores improved from preoperative means of 21.6 ± 6.5 and 25.2 ± 8.5 to 65.6 ± 20.7 points and 56.8 ± 16.5 points, respectively (P < .001). The PASS values for the ASES and CM scores were 62.4 and 52.5, respectively. The univariate analysis showed that older age (P = .021), presence of pseudoparalysis (P < .001), previous surgery (P = .016), lower preoperative AHI (P = .028), and lower AHI reversibility (P < .001) were all significantly associated with worse patient satisfaction. The multivariable logistic regression analysis showed that pseudoparalysis (P = .038) and AHI reversibility (P = .021) were independent prognostic factors affecting the achievement of a PASS after arthroscopic-assisted LDTT. The cutoff value for AHI reversibility to predict an achievement of PASS was found to be 4.0 mm.

CONCLUSIONS

Arthroscopic-assisted LDTT led to satisfactory results in patients with massive rotator cuff tears. However, pseudoparalysis and AHI reversibility were the most important independent prognostic factors that consistently reduced and increased, respectively, the odds of achieving a PASS.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Evaluation of anatomical variations with morphological measurements and their relationship with rotator cuff tear and acromion types

Introduction: There many more anatomical measurements such as the acromiohumeral distance and lateral acromion angle and acromial configuration was reported as might be associated with rotator cuff tear. In our study, we aimed to reveal the effect of acromion index, acromiohumeral distance, lateral acromion angle, critical shoulder angle values and the acromion type in the development of rotator cuff tear. Material and Method: In our retrospective study, 58 patients and 29 asymptomatic volunteers who underwent shoulder magnetic resonance imaging examinations were examined. acromion index, acromion humaral distance, lateral acromion angle and critical shoulder angle were measured and their relationship with rotator cuff tear and acromion types were evaluated. Results: Type III (hooked) of acromial shapes, higher acromion index and critical shoulder angle values, lower acromiohumeral distance and lateral acromion angle values are more frequently seen in rotator cuff tear patients, in our study. Conclusion: Thus, we revealed anatomical malformations that predispose to rotator cuff tear concerning the shoulder joint.

Volumetric evaluation of the subacromial space in shoulder impingement syndrome

INTRODUCTION

Shoulder impingement syndrome is evaluated radiologically with two-dimensional measurement parameters. None of these measurement parameters accurately reflect the three-dimensional geometry. The purpose of this study was to evaluate the volumetric status of the subacromial space in patients with shoulder impingement syndrome and to investigate its relationship with two-dimensional parameters.

HYPOTHESIS

The primary hypothesis of this study is that subacromial volume is reduced in patients with impingement syndrome. The second hypothesis is that the sagittal plane morphology of the acromion reflects the subacromial volume better than the coronal plane morphology.

PATIENTS AND METHODS

This retrospective study consisted of a total of 52 participants: 26 patients with impingement syndrome and 26 controls. Volumetric measurements were performed with using magnetic resonance imaging. The relationship between humerus and acromion was evaluated by acromiohumeral distance. The sagittal plane morphology of the acromion was evaluated with an objective acromial angle, while the coronal plane morphology was evaluated with a lateral acromial angle. The radiological parameters between groups were compared.

RESULTS

The mean subacromial volume was significantly smaller in the impingement group compared to the control group (p=0.01). The subacromial volume had a negative correlation with the objective acromial angle (R=-0.46; p=0.01) The mean tendon volume was significantly higher in the impingement group (p<0.001). The mean acromiohumeral distance in the impingement group (6.8mm±1.0mm), was calculated to be significantly lower than the control group (10.1mm±1.5mm) (p<0.001). There was a positive moderate correlation between subacromial volume and acromiohumeral distance (R=0.61; p=0.01).

DISCUSSION

This is the first study to demonstrate a reduction in subacromial volume in patients with impingement syndrome. The sagittal plane morphology of the acromion, rather than the coronal plane, appears to be more closely related to the subacromial volume.

LEVEL OF EVIDENCE

III; case-control study.

Evaluation of bilateral acromiohumeral distance on magnetic resonance imaging and radiography in patients with unilateral rotator cuff tears

INTRODUCTION

The aim of this study was to evaluate the difference in the acromiohumeral distance (AHD) between the shoulders with full-thickness rotator cuff tear and contralateral healthy shoulders of the same patients on magnetic resonance imaging (MRI) and radiograph.

MATERIALS AND METHODS

We included 49 patients with unilateral full-thickness rotator cuff tears. The mean age of the patients (29 women and 20 men) was 54.57 ± 7.10 years. The shoulders were divided into those with a full-thickness rotator cuff tear and healthy shoulders. The mean AHDs on radiograph and MRI were calculated by two radiologists experienced in the musculoskeletal system. Shoulders with rotator cuff tears on coronal plane and sagittal MRI were divided into 3 (Patte I, II, III) and 4 subgroups (S: superior, AS: anterosuperior, PS: posterosuperior, APS: anteroposterosuperior), respectively. The relationship between the groups and the subgroups was statistically investigated.

RESULTS

The mean AHDs on radiograph were 6.93 and 9.11 mm and on MRI were 5.94 and 7.46 mm in the patient and control groups, respectively. The mean AHDs were 6.47, 6.03, and 4.95 mm in Patte I, II, and III, respectively. The difference between the subgroups was statistically significant. According to the sagittal plane topography, the mean AHDs (mm) were 6.39, 6.44, 5.8, and 4.6 mm in the superiorly, anterosuperiorly, posterosuperiorly, and anteroposterosuperiorly localized lesions, respectively. The relationship between S and AS was not statistically significant, and those between S and PS, AS and PS, S and APS, and PS and APS were significant.

CONCLUSIONS

In patients with unilateral full-thickness rotator cuff tear, AHD narrowing was observed on the törnekler side after evaluating the bilateral acromiohumeral distance on MRI and radiograph. AHD was significantly reduced by increasing the degree of supraspinatus tendon retraction in the coronal plane MRI and by the posterosuperior and anteroposterosuperior location of the rotator cuff tear in the sagittal plane MRI.

The acromiohumeral distance in the MRI should not be used as a decision criterion to assess subacromial space width in shoulders with an intact rotator cuff

PURPOSE

The acromiohumeral distance is in practice often evaluated on MRI by radiologists and a reduction diagnosed as subacromial impingement. However, the acromiohumeral distance as indicator for a decentered glenohumeral joint is defined on a true AP radiograph with the patient standing or sitting. The present study therefore evaluated the influence of the patient position by comparing the acromiohumeral distance in both modalities in shoulders with an intact rotator cuff.

METHODS

On MRI images and true AP radiographs of patients > 20 and < 80 years with an intact rotator cuff the acromiohumeral distance was measured. The maximum cranio-caudal size of the glenoid was measured as a reference to allow a direct comparison of both modalities.

RESULTS

Two-hundred and thirty-four shoulders (mean patients age 45.8 ± 14.3 years) were included. The mean acromiohumeral distance/glenoid size ratio of all shoulders was significantly larger (P < 0.0001) on the MRI with 4.6 ± 1.0 in comparison to 4.1 ± 0.9 in the radiographs indicating a smaller acromiohumeral distance on the MRI. In absolute values, a mean acromiohumeral distance of 9.2 mm ± 1.8 on MRI in comparison to 10.4 mm ± 2.4 on the radiographs was calculated. Herewith, the acromiohumeral distance in the MRI was in the average 1.2 mm ± 2.1 (13%) smaller than the in corresponding radiographs (P < 0.0001).

CONCLUSION

The acromiohumeral distance is significantly smaller in the MRI in comparison to AP radiographs in shoulders with an intact rotator cuff and should not be used as a decision criterion on MRI to assess glenohumeral centering or subacromial space width.

LEVEL OF EVIDENCE

IV.

Superior capsular reconstruction using a porcine dermal xenograft for irreparable rotator cuff tears: outcomes at minimum two-year follow-up

PURPOSE

To evaluate midterm outcomes of arthroscopic superior capsular reconstruction (SCR) using a decellularized porcine dermal xenograft in patients with massive, irreparable rotator cuff tears and to determine the influence of concomitant, repairable subscapularis tears.

METHODS

This is a retrospective study of 56 patients with a minimum 2-year follow-up. Preoperative and postoperative range of motion, American Shoulder and Elbow Surgeons score, Subjective Shoulder Value, and visual analog score for pain were measured. Postoperative data were collected at 3, 6, 12, 24, and 36 months.

RESULTS

Of the 56 patients who underwent arthroscopic SCR, there were 39 men and 17 women. The mean age at operation was 65 ± 9 years, and the mean follow-up was 34 ± 8 months. The mean preoperative American Shoulder and Elbow Surgeons improved from 41 ± 19 to 78 ± 18 at 24 weeks, to 86± 16 at 12 months, and to 90±9 at 24 months, P < .0001. Similarly, the mean preoperative Subjective Shoulder Value improved from 39 ± 17 to 74 ± 18 at 24 weeks, to 80 ± 18 at 12 months, and to 80 ± 11 at 24 months, P < .0001. The mean preoperative visual analog score improved from 6.5 ± 2.1 to 1.4 ± 2.2 at 24 weeks, to 0.7± 1.1 at 12 months, and to 0.2 ± 0.4 at 24 months, P < .0001. There were no differences in outcome scores between patients with intact vs. repaired subscapularis. Similarly, no statistically significant differences were found in forward flexion or external rotation after SCR between patients with an intact vs. repaired subscapularis. Failure of the SCR graft was observed on magnetic resonance imaging in 14 patients, 4 of whom opted for revision to reverse shoulder arthroplasty. Eleven patients were truly pseudoparalytic before surgery; in 5 cases, pseudoparalysis was reversed after SCR.

CONCLUSIONS

SCR can alleviate pain and disability from irreparable rotator cuff tears and provide significant improvements in shoulder function; however, the xenograft technique resulted in inconsistent reversal of true pseudoparalysis. No difference was found between patients who required concomitant subscapularis repair vs. those who did not.

Increased T2 signal intensity in the distal clavicle does not justify acromioclavicular resection arthroplasty during rotator cuff repair

INTRODUCTION

Acromioclavicular (AC) arthropathy can contribute to shoulder pain; it can be treated surgically by distal clavicle resection (DCR). The aim of this study was to determine whether increased T2 signal intensity in the clavicle on MRI is an argument in favour of AC resection arthroplasty by DCR during rotator cuff repair.

METHODS

The MRI images from 107 shoulders in 107 patients were analysed. We looked for statistical relationships and correlations between shoulders with T2 hyperintensity (HI+) and those without (HI-) before surgery and then in shoulders with T2 hyperintensity (HI+) that underwent AC resection arthroplasty (AC+) and those who did not (AC-).

RESULTS

On MRI, T2 hyperintensity in the AC joint was correlated with sex (more often found in men) and radiological signs of AC arthropathy. There was no statistical correlation before surgery, particularly with AC pain, or after surgery, with outcomes in shoulders undergoing DCR.

CONCLUSION

When repairing rotator cuff tears, the presence of T2 hyperintensity on MRI in the distal clavicle is not a predictor of better clinical outcomes after AC resection arthroplasty is done. The AC pain may be related to the rotator cuff tear instead.

LEVEL OF EVIDENCE

II, prospective randomised study.

Prediction of Rotator Cuff Injury Associated with Acromial Morphology: A Three-Dimensional Measurement Study

Objective

To analyze the relationship between the acromial morphology and the related rotator cuff injury using a three‐dimensional (3D) measurement technology.

Methods

For the present study, 226 patients (113 men and 113 women) who underwent shoulder Coarthroscopy from June 2015 to December 2019 at the Department of Orthopedics at our hospital were selected retrospectively. A total of 113 shoulder joints of age‐matched healthy people were selected as the control group. A 3D model coordinate system of the shoulder was established based on CT scan images. Patients were grouped according to the condition of the rotator cuff injury during surgery. The patients whose rotator cuff tear site corresponded to the 3D osseous proliferative structure of the acromion were classified into the impingement injury group (II group). The other patients were classified into the non‐impingement injury group (NII group). The acromiohumeral interval (AHI), the acromial anterior protrusion (AAP), the acromial inferior protrusion (AIP), the acromioclavicular angle (AC angle), the distance from the most medial edge of the acromial anterolateral protrusion (AALP) to the most lateral point of acromion (MLPA) (a), the distance from the most posteromedial edge of the AALP to the MLPA (b), the anteroposterior diameters of the AALP (c), and the proportion of anteroposterior diameters of AALP to the anteroposterior diameters of acromion, (c/c + d) × 100(%), were measured using the 3D shoulder model.

Results

The results of the intraobserver (<5%) and interobserver variability (>87%) analysis found the parameters to have high intraobserver and interobserver concordance. There were no significant differences in age among the control group, the NII group, and the II group (P = 0.8416). There were significant differences in AAP among the three groups (P = 0.0374). The results were the same for men and women, respectively. The AAP in the control group and the NII group did not show a difference, while the AAP in the II group was increased by 26.9% (P = 0.015) and 25% (P = 0.023), respectively, compared with the NII group and the control group. AHI, AIP, and AC angles did not show significant differences among the three groups (P > 0.05). The (a) and (b) of the II group were significantly larger than those of the NII group; P‐values were 0.0119 and 0.0003, respectively. The (a) and (b) in patients with rotator cuff injuries were larger than in the normal population (P < 0.05). The above results were the same for men and women. This suggested that the larger width of the AALP might cause the related rotator cuff injury. The (c/c + d) in the II group was significantly larger than those in the control and the NII groups, with P‐values of 0.0005 and 0.0021, respectively. The risk of rotator cuff injury due to subacromial impingement was increased when the maximum width of the medial–lateral edge of the AALP exceeded 16.8 mm (17.4 mm in men, 15.1 mm in women), the maximum width of the posterior edge of the AALP exceeded 12.9 mm (13.8 mm in men,12.7 mm in women), or the anteroposterior diameters of the AALP exceeded the anteroposterior diameters of the acromion by 33.5%.

Conclusion

We could predict the occurrence and development of the related rotator cuff injury in symptomatic patients with specific 3D changes in their acromion and intervene in the acromion of such patients as early as possible to prevent possible rotator cuff injuries in the future.