Release of the coracoacromial ligament can lead to glenohumeral laxity: a biomechanical study

Modified Suture Button Latarjet Procedure With Coracoacromial Ligament And Pectoralis Minor Preservation Achieves Good Clinical Outcomes at 2-Year Follow-up: Case Series of Latarjet Technique

PURPOSES

To evaluate if the modified suture button Latarjet procedure with coracoacromial ligament (CAL) and pectoralis minor (PM) preservation could achieve excellent outcomes at the 2-year follow-up.

METHODS

During January 2019 to January 2021, data of patients who underwent the modified suture button Latarjet with CAL and PM preservation in our department was collected. The glenoid bone loss of these patients were above 20% or over 10% with high demands for exercise. Partial coracoid osteotomy was based on the results of the preoperative 3-dimensional computed tomography (3D CT) evaluation of the glenoid defect area (GDA) and corresponding coracoid process morphology. The preoperative and postoperative clinical results were assessed. The minimal clinically important difference (MCID) was utilized to compare improvement in clinical outcomes. Graft-glenoid union and remodeling were assessed using postoperative 3D CT, and magnetic resonance imaging (MRI) was performed to confirm the integrity of the CAL and PM postoperatively.

RESULTS

35 patients were included in this study; the mean follow-up time was 26.9 ± 1.9 months. No case of recurrent dislocation or sublaxity. Significant improvements were observed in mean visual analog scale (VAS) scores for pain during motion, American Shoulder and Elbow Surgeons (ASES) score, Rowe score, and Walch-Duplay score (P < .001). The percentage of patients achieving at least an MCID improvement in clinical outcomes was: VAS 85.71%; ASES 97.14%; Rowe 100%; Walch-Duplay 97.14%. 33 patients (94.3% of all cases) were able to return to their preoperative sport levels, 34 grafts (97.1%) achieved bone union (1 soft union) in 6.3±2.2 months, and the coracoid grafts restored 97.1±4.0% of the perfect fitting circle (PFC) at the last follow-up. Postoperative CT scan showed that 31 grafts (88.6%) were placed ideally in vertical view. In the axial view, 25 grafts (82.9%) were flushed to the glenoid, whereas 1 and 5 grafts were fixed medially and laterally, respectively. The CAL and PM were visualized postoperatively. No arthropathy was observed in any patient at the last follow-up.

CONCLUSIONS

The modified suture button Latarjet procedure with CAL and PM preservation obtained good clinical and radiological results without recurrence or complications. A substantial majority of patients (>85%) achieved the MCID for the VAS, ASES, ROWE, and Walch-Duplay scores. Additionally, the malpositioned graft (17.1%) did not cause arthropathy of the joints at 2-year follow-up.

Rotator Cuff Repair With or Without Acromioplasty: A Systematic Review of Randomized Controlled Trials With Outcomes Based on Acromial Type

BACKGROUND

It is unclear whether the use of concomitant acromioplasty during rotator cuff repair (RCR) improves clinical outcomes and whether the outcomes are affected by acromial type.

PURPOSE

To perform a systematic review of randomized controlled trials comparing clinical outcomes of RCR with and without acromioplasty, with a subanalysis of outcomes based on acromial type.

STUDY DESIGN

Systematic review; Level of evidence, 2.

METHODS

A systematic review was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines by searching PubMed, the Cochrane Library, and Embase to identify randomized controlled trials that directly compared outcomes between RCR with versus without acromioplasty. A subanalysis was performed on the studies that provided outcomes based on acromial type. The search phrase used was rotator cuff repair (acromioplasty OR subacromial decompression) randomized. Patients were evaluated based on retear rate, reoperation rate, and patient-reported outcomes (PROs).

RESULTS

Application of inclusion criteria yielded 5 studies (2 studies were level 1, and 3 studies were level 2) including a total of 409 patients, with 211 patients undergoing RCR alone (group A) and 198 patients undergoing RCR with acromioplasty (group B). The mean patient age was 58.5 and 58.3 years in groups A and B, respectively. The mean follow-up time was 52.9 months, and the overall percentage of male patients was 54.1%. The rotator cuff tear size was 20.7 mm and 19.8 mm for groups A and B, respectively. No significant differences were found between groups for any of the PROs at final follow-up. Overall retear rates did not significantly differ between groups based on acromial type. Between 2 studies that measured reoperation rate, a significantly higher reoperation rate was found for the nonacromioplasty group (15%) versus the acromioplasty group (4.1%) (P = .031). One of these studies found that 5 of 9 patients (56%) with a type III acromion in the nonacromioplasty group underwent reoperation compared with 0 of 4 patients with a type III acromion in the acromioplasty group.

CONCLUSION

There is some evidence that acromioplasty during RCR reduces the risk for later reoperation. This may be particularly true for patients with type III acromions, although further studies with larger sample sizes are needed to corroborate these data.

Adaptive pathology: new insights into the physical examination and imaging of the thrower's shoulder and elbow

Throwing with high velocity requires extremes of glenohumeral external rotation of the abducted arm where particularly high forces in the shoulder and elbow are endured. Repeated throwing leads to dominant-arm bony remodeling of the humerus, glenoid, and elbow, and multiple soft tissue changes that would be considered abnormal. Many of these features are thought to be adaptive and protective. The purpose of this work is to (1) define the concept of adaptive pathology; (2) review the mechanics of the throwing motion; (3) review pertinent physical examination and imaging findings seen in asymptomatic throwers' shoulders and elbows and describe how these changes develop and may be adaptive-allowing the thrower to perform at high levels; and then (4) review the principles of surgical treatment in the throwing athletes, which should focus on reducing symptoms, but not necessarily restoring the thrower's anatomy to normal.

Changes in Scapular Function, Shoulder Strength, and Range of Motion Occur After Latarjet Procedure

Purpose

To evaluate the current literature on the effects of anatomic changes caused by the Latarjet procedure and to identify areas for future research.

Methods

English-language studies that addressed the consequences of anatomic alterations after the open Latarjet procedure were included. Articles written in languages other than English, reviews, and case reports were excluded. Titles and abstracts were screened by 2 authors. Studies that met the inclusion criteria were screened by the same authors. The following data were extracted from the included studies: authors, year of publication, journal, country of origin, aims or purpose, study population and sample size, methods, procedure, intervention type, and key findings that relate to the scoping review questions.

Results

Twenty-two studies were included for analysis, yielding the following findings: First, the Latarjet procedure may change the position of the scapula owing to pectoralis minor tenotomy and/or transfer of the conjoint tendon. Second, dissection of the coracoacromial ligament may result in increased superior translation of the humeral head. The impact of this increased translation on patients' function remains unclear. Third, the subscapularis split shows, overall, better internal rotation strength compared with subscapularis tenotomy. Fourth, passive external rotation may be limited after capsular repair. Fifth, despite the movement of the conjoint tendon, elbow function seems unchanged. Finally, the musculocutaneous nerve is lengthened with a changed penetration angle into the coracobrachialis muscle, but the clinical impact seems limited.

Conclusions

The Latarjet procedure leads to anatomic and biomechanical changes in the shoulder. Areas of future research may include better documentation of scapular movement (bilateral, as well as preoperative and postoperative) and elbow function, the effect of (degenerative) rotator cuff ruptures after the Latarjet procedure on shoulder function, and the impact of capsular closure and its contribution to the development of glenohumeral osteoarthritis.

Clinical Relevance

This comprehensive overview of anatomic changes after the Latarjet procedure, with its effects on shoulder and elbow function, showed gaps in the current literature. Orthopaedic shoulder surgeons and physical therapists could use our findings when providing patient information and performing future clinical research.

Acromioclavicular joint Stabilization: Our experience with the lockdown technique

Background

Acromioclavicular joint (AC joint) disruption is a common injury with considerable variation with regards to surgical management. The Lockdown™ procedure (previously known as Surgilig™), Modified Weaver-Dunn procedure, Arthroscopic AC joint stabilization and Ligament Augmentation and Reconstruction system (LARS) procedure have all been described for treatment of this injury with varying outcomes.

Purpose

To measure the functional and radiological outcomes following all cases of AC joint reconstruction using the Lockdown™ technique over the last 10 years at Medway Maritime Hospital.

Methods

Data on a total of 53 patients who underwent AC joint reconstruction between 2012 and 2021 were collected. Electronic records were used to extract data regarding patient characteristics, surgery details, and duration of follow-up. Telephonic interviews of patients were conducted to collect data on hand dominance, surgical complications, and responses to Oxford shoulder score (OSS) and QuickDASH score questionnaires. Hospital PACS data were reviewed to record preoperative injury severity and postoperative acromioclavicular joint reduction.

Results

Results for 42 patients were available and analysed as 10 could not be contacted and 1 patient sadly passed away. Of the patients reviewed, 92.9% were males with a mean age of 42.2 years (Range 16-67 years) and mean follow up of 68 months (12-119.1 months). The injury involved the dominant arm in 59.5%cases. Majority of the cases were Rockwood type V injuries (71.43%) while the rest were either type III(19.05%) or type IV(9.52%).The mean preoperative OSS was 21.3/48 which improved to 44.3/48 in the postoperative period. Similarly, the mean QuickDASH score was 50.6 preoperatively, that improved to 9.1 postoperatively.The most common patient reported complication was prominent metalwork seen in 5 cases (11.6%) followed by stiffness seen in 3 cases (7%) and superficial infection seen in 1 case (2.3%). The AC joint remained reduced radiologically in 81% of cases, while a resubluxation between 50 and 100% was seen in the rest of the cases. Patients with radiological resubluxation did not report this as a complication in 87.5% of the cases. Overall, 38 patients reported their outcome as excellent, 2 patients rated it good while 1 patient reported it as fair and 1 as poor.

Conclusion

The Lockdown™ technique for stabilization of AC joint has excellent or good patient satisfaction in 95.2% of cases in long term follow up of more than 5.7 years. Prominent metalwork and stiffness are the commonest clinical complications. Radiological resubluxation can be seen in a fifth of the cases but does not directly lead to patient dissatisfaction.

Level of evidence

Level IV Retrospective case series.

Association of Coracoacromial Ligament Degeneration With Rotator Cuff Tear Patterns and Retear Rate

Background

Coracoacromial ligament (CAL) degeneration is thought to be a factor in external impingement in bursal-sided rotator cuff tears, but CAL release is associated with adverse effects.

Purpose

To investigate the association between CAL degeneration and the patterns of massive rotator cuff tears using multiple modalities and to assess the effect of CAL degeneration on supraspinatus tendon retear rates.

Study Design

Cohort study; Level of evidence, 2.

Methods

The authors prospectively recruited 44 patients who had undergone arthroscopic rotator cuff repair without acromioplasty or CAL release. Preoperative radiographs and magnetic resonance imaging (MRI) scans were reviewed to determine acromial morphology and CAL thickness, respectively. Rotator cuff tears were categorized as isolated supraspinatus or massive (involvement of ≥2 tendons), with massive tears categorized using the Collin classification. Acromial degeneration was analyzed using the Copeland-Levy classification. The CAL was biopsied intraoperatively and histologically analyzed using the Bonar score. At 6-month follow-up, the integrity of the repaired supraspinatus tendon was analyzed on MRI using the Sugaya classification. Finally, the associations among CAL degeneration, rotator cuff tear pattern, and arthroscopic grading were investigated.

Results

Patients with Collin type B rotator cuff tear had significantly higher CAL Bonar scores than those with Collin type A or isolated supraspinatus tears (10.0 vs 6.8 and 3.4; P = .03 and P < .001, respectively). Patients with a degenerative acromial undersurface of Copeland-Levy stage 2 or 3 had CALs with significantly higher Bonar scores than those with an intact acromial undersurface (8.4 and 8.2 vs 3.5; P = .034 and P = .027, respectively). The CAL Bonar scores of patients with different stages of the 6-month postoperative Sugaya classification were comparable (6.5, 7.2, 8.0, and 7.8 for stages 1, 2, 3, and 4, respectively; P = .751).

Conclusion

CAL degeneration was more severe in anterosuperior-type massive rotator cuff tears. Interestingly, even without acromioplasty, the severity of CAL degeneration did not affect the retear rate of the supraspinatus tendon.

Effect of arthroscopic subacromial decompression during arthroscopic repair of small to medium-sized rotator cuff tears

Background

Although arthroscopic subacromial decompression (ASD) is a commonly used procedure during arthroscopic rotator cuff repair (ARCR), the effect of ASD on the clinical outcomes for ARCR is controversial. The purpose of this study was to compare the clinical outcomes of ARCR with or without ASD.

Methods

Patients (n = 315 with 320 shoulders) who underwent ARCR for small to medium-sized rotator cuff tears were followed for at least 24 months. ARCR was performed with ASD (180 shoulders, group A) or without ASD (140 shoulders, group N). There were no significant differences in patient demographics, including mean age and mean follow-up time. Rotator cuff repair was performed using the suture-bridge technique in all shoulders, and all patients were treated using the same rehabilitation protocol after surgery. University of California at Los Angeles score, Constant score, re-tear rates, revision surgery rates, and operating time were compared between groups. Re-tear was defined as Sugaya classification Types 4 and 5 using postoperative magnetic resonance imaging at more than 12 months.

Results

There was no statistically significant difference in clinical outcomes before and after ARCR between groups. However, the University of California at Los Angeles scores and Constant scores significantly improved in both groups after surgery (P < .001). Furthermore, there was no major difference in the re-tear rates between groups A (7/180 shoulders, 3.9%) and N (11/140 shoulders, 7.9%) (P = .146). Revision surgeries were performed on 3/180 shoulders (1.7%) in group A (due to postoperative deep infection in one shoulder and revision ARCR for re-tear in two shoulders). No revisions surgeries were needed in group N patients (P = .259). The mean surgical time for group A was 62.0 ± 27.0 minutes (29-138 min.) and 52.4 ± 26.1 minutes (17-124 min.) for group N (P = .007).

Conclusion

These results suggest that ASD has a limited effect on clinical outcomes of ARCR for small to medium-sized rotator cuff tears.

LUtarjet-limit unique coracoid osteotomy Latarjet (With video)

Background

The Latarjet procedure is an effective technique for the treatment of recurrent anterior shoulder dislocation with glenoid bone loss. However, the inevitable destruction of the coracoacromial arch may result in humeral head translation. The aim of the study is to introduce a modified Latarjet technique with coracoacromial arch preservation as well as its short term clinical outcomes.

Methods

We propose a novel individualized flexible arthroscopic suture button fixation Latarjet technique called `LUtarjet' with video. Precise measurements of the coracoid process, glenoid deficiency and osteotomy plane were made preoperatively. Only three arthroscopic portals were needed and limit unique coracoid osteotomy was performed with coracoacromial arch preservation. The mini window splitting of the subscapularis was performed from the posterior to the anterior direction and the split window was as small as 8–10 mm in length.

Results

A total of 27 patients (25.6 ± 5.4 years) were included in the study. The average surgical duration was 55.6 ± 6.3 min and the mean follow-up time was 8.1 ± 1.5 months. The functional score was significantly improved at the last follow-up. Radiologic evidence showed that the bone graft healing was placed in the desired position. No complications were found.

Conclusions

We present a fast, easy, accurate, safe arthroscopic ‘LUtarjet’ technique called FEAST that can simplify the arthroscopic Latarjet process and achieve a satisfactory bone graft position and satisfactory short-term clinical outcomes.

Level of evidence

IV, case series.

The Effect of Acromioplasty or Bursectomy on the Results of Arthroscopic Repair of Full Thickness Rotator Cuff Tears: Does the Acromion Type Affect These Results?

Objectives:

The aim of this study was to investigate the effect of subacromial decompression on the results of full thickness rotator cuff repair applied arthroscopically. Examination was also made of the effect of acromion type on the subacromial decompression procedure in patients applied with arthroscopic rotator cuff repair.

Methods:

The study included a total of 150 patients, comprising 102 (68%) females and 48 (32%) males with a full thickness rotator cuff tear repaired arthroscopically. The patients were separated into three groups of 50. Group A comprised those with acromioplasty and bursectomy applied additional to the repair. In Group B, only bursectomy was performed additional to the repair and in Group C, only rotator cuff repair was applied. Evaluation was made of the post-operative long-term pain and functional results.

Results:

The mean age of the cases was 65.63±9.22 years (range, 46–86 years). The affected side was right side in 95 (63.3%) cases and left side in 55 (36.7%). No statistically significant difference was determined between the groups according to the post-operative Constant Murley and ASES scores (p>0.05). In the paired comparisons, the post-operative VAS scores of Group C were higher than those of Groups A and B (p=0.018, p=0.029, p<0.05). No statistically significant difference was determined between Group A and Group B in respect of the post-operative VAS scores (p>0.05).

Conclusion:

In the arthroscopic repair of full thickness rotator cuff tears, neither acromioplasty, coracoacromial ligament loosening nor bursectomy were determined to have any positive effect on the results. Whatever the acromion type, there is no need for an additional subacromial decompression procedure after rotator cuff repair, in respect of pain and functional outcomes. Only acromial spurs should be gently removed paying attention to the coraco-acromial ligament.

Effect of Modified Arthroscopic Latarjet on Acromiohumeral Distance at 5-Year Follow-up

Background:

It is unclear whether coracoacromial ligament release during the Latarjet procedure will increase superior translation of the shoulder joint.

Purpose:

To evaluate whether a modified suture button Latarjet procedure can decrease the acromiohumeral distance (AHD).

Study Design:

Case series; Level of evidence, 4.

Methods:

A retrospective analysis was conducted among 155 patients who underwent a modified suture button Latarjet procedure between 2013 and 2015. AHD was measured on bilateral computed tomography scans taken preoperatively and on scans of the affected shoulder taken on postoperative day 1 and postoperative month (POM) 6, POM 36, and POM 60. At each time point, we recorded pain on a visual analog scale (VAS) and objective shoulder function using the American Shoulder and Elbow Surgeons, Rowe, and Walch-Duplay scores. Preoperative and final follow-up VAS and functional scores were compared using the paired t test. Pairwise comparison of AHD values at each follow-up time point were compared with the preoperative intact side using the paired t test. Intra- and interobserver reproducibility of the AHD measurements was evaluated using the intraclass correlation coefficient.

Results:

A total of 104 patients who met the criteria completed the final follow-up, which occurred at 62.6 ± 2.4 months (mean ± SD). When compared with presurgery, the VAS and all functional scores improved significantly at the last follow-up (P < .001 for all). Intra- and interobserver intraclass correlation coefficients indicated good reliability for the ADH measurements. Preoperatively, there were no differences in AHD values between the intact and affected shoulders (7.8 ± 0.8 mm for both; P = .851). The AHD values at postoperative day 1 and POM 6, POM 36, and POM 60 were 9.6 ± 0.7 mm, 8.6 ± 0.9 mm, 8.0 ± 0.8 mm, and 7.9 ± 0.8 mm, respectively, all of which were larger than those of the preoperative intact side (P < .001 for all).

Conclusion:

The modified suture button Latarjet procedure not only offered satisfactory therapeutic effects but also did not decrease the AHD at 5-year follow-up.

Clinical outcome and return to sports activity after surgical treatment for recurrent shoulder instability with a modified Latarjet procedure

INTRODUCTION

The Latarjet procedure is an attractive surgical option for the management of chronic anterior shoulder instability. The original surgical approach involves the vertical tenotomy of the subscapularis tendon. Alternatively, the subscapularis muscle is split longitudinally and the tendon left attached at the lesser tuberosity.

HYPOTHESIS

The hypothesis is that the longitudinal split is of functional advantage and may lead to better functional results and earlier return to sports activities compared to the vertical tenotomy.

MATERIAL AND METHODS

Thirty-two patients were included in this retrospective cohort study. In 14 patients, the subscapularis tendon was vertically incised (group A), whereas in 18 patients, the subscapularis muscle was split longitudinally (group B). Patients were evaluated at 1 year (FU1) and 2 years (FU2) after the Latarjet procedure. Results at follow-up were correlated with patient-specific data and compared with the preoperative status. Primary outcomes were the functional assessment based on Western Ontario Shoulder Instability (WOSI) index and Constant Score (CS) and the assessment of the return to sports activity. Patients' demographics, duration of surgery, and the rate of recurrent dislocations were recorded as secondary variables.

RESULTS

All patients started their sports activities with a mean±SD of 12.41±1.24 weeks. Interestingly, the time from surgery to full recovery of sports activities was significantly longer for group A (mean±SD of 30.17±10.36 weeks) compared to group B (mean±SD of 20.71±3.67 weeks). There is a statistically significant decrease of the WOSI score from the preoperative level compared to FU1 and FU2, indicating a decrease in instability related symptoms during the entire follow up period with no statistically significant difference between group A and B. There is an increase in shoulder function during the entire follow up period based on the CS. Most interestingly, there is a statistically significant difference between group A and B at FU1, indicating a significantly better shoulder function for group B at the early follow up timepoint (FU1). At the later follow up timepoint (FU2), no difference exists in the individual items. However, a significantly better total CS remains in group B, indicating an overall improved function compared to group A.

DISCUSSION/CONCLUSION

The longitudinal split of subscapularis muscle is a safe approach which leads to quicker functional recovery and return to sports activity compared to the vertical tenotomy, which is a benefit especially for active individuals. It is therefore recommended as the standard surgical approach.

LEVEL OF EVIDENCE

III; Retrospective cohort study.

The Angular Relationships Between the Coracohumeral Ligament and Adjacent Shoulder Structures Are Variable

Purpose

To describe the arthroscopic anatomy of the coracohumeral ligament (CHL) in relation to visible anatomic reference points to aid in the execution of a more effective arthroscopic medial-lateral rotator interval closure.

Methods

Detailed dissection to identify the CHL was performed in 4 shoulders from 2 fresh-frozen donor cadavers with a deltopectoral approach. The angular relationship between the CHL and the superior border of the subscapularis tendon was determined via gross dissection. Arthroscopic images were used to determine the angular position of the CHL in relation to both the glenoid articular surface and the intraarticular segment of the tendon of the long head of the biceps brachii (LHB).

Results

Analysis of 4 cadaveric shoulders via gross dissection demonstrated the CHL to subtend a mean angle of 29° (range 16° to 39°) with respect to the superior border of the subscapularis tendon. Arthroscopic analysis of 4 cadaveric shoulders demonstrated the CHL to subtend a mean angle of 59° (range 38° to 77°) with respect to the glenoid articular surface. Additionally, arthroscopic analysis of 2 cadaveric shoulders demonstrated the CHL to subtend a mean angle of 29° (range 11° to 47°) with respect to the LHB tendon.

Conclusion

Although the position of the CHL in relation to the subscapularis tendon, glenoid articular surface, and LHB tendon demonstrates a moderate degree of anatomic variability, these structures provide valuable anatomic reference points for the identification of the course of this significant static shoulder stabilizer.

Clinical Relevance

Comprehensive understanding of the angular relationships between the CHL and adjacent shoulder structures may assist with the execution of a more effective arthroscopic rotator interval closure.

Morphology of the Undersurface of the Anterolateral Acromion and Its Relationship to Surrounding Structures

Background:

A better understanding of the morphology underneath the acromion is needed to prevent complications after arthroscopic subacromial decompression. The precise correlations between the morphologic features underneath the acromion and the surrounding structures including the attachment of the coracoacromial ligament (CAL) and the origin of the deltoid middle head have not yet been determined in the absence of artifacts on the bony surface caused by dissection techniques. Moreover, anatomic findings in previous studies using only older-aged cadavers or dried bones may not reflect the morphologic features of younger and healthy specimens.

Purpose:

To characterize the anterolateral structures morphologically in the inferior aspect of the acromion, assess the relationships of these structures with surrounding structures without dissection artifacts on the bony surface, and verify the cadaveric data in the asymptomatic shoulders of living middle-aged patients.

Study Design:

Descriptive laboratory study.

Methods:

We initially analyzed the relationship between the morphology of the anterolateral structures and surrounding structures in 18 cadaveric shoulders (mean age, 81.8 years), 15 of which were subjected to macroscopic investigation of the CAL attachment and 3-dimensional micro—computed tomography investigation with radiopaque markers and 3 of which were subjected to histologic examination. We also analyzed the morphology underneath the anterolateral acromion in 24 asymptomatic shoulders of middle-aged patients (mean age, 54.8 years) to verify the cadaveric data. In both the cadaveric shoulders and the asymptomatic shoulders of live patients, the long axis, width, and height of the anterolateral prominence were measured by use of 3-dimensional CT imaging.

Results:

In cadavers, the anterolateral prominence underneath the acromion corresponded to the attachment of the CAL. Histologic evaluation revealed that the CAL was continuous to the deep layer of the deltoid middle head in the lateral acromion. The study in asymptomatic shoulders of middle-aged patients revealed bony prominences similar to those observed in cadavers.

Conclusion:

The anterolateral prominence, which corresponds to the attachment of the CAL below the acromion, may be a native structure below the acromion. Moreover, the CAL is continuous to the deep layer of the deltoid middle head in the lateral acromion.

Reconstruction of the Coracoacromial Ligament during a Modified Latarjet Procedure for the Treatment of Shoulder Instability: Clinical Outcome at Minimum 5 Years Follow-Up

OBJECTIVE

The function of the coracoacromial ligament (CAL) in superior shoulder stability has been well established, and the release of the CAL with the Latarjet procedure leads to increased superior humeral translation. A surgical technique was developed recently to reconstruct the CAL during a modified Latarjet procedure, and the clinical outcome of this technique at medium-term follow-up is yet to be determined.

METHODS

Twenty-six patients with chronic post-traumatic anterior shoulder instability were included in this retrospective case-control study. Patients in group 1 (n = 12) were surgically treated with the classic congruent-arc Latarjet, where the CAL is sacrificed. In group 2 (n = 14), the CAL was reconstructed using a pectoralis minor fascia flap (PMFF). Primary outcomes were the return to sports activity and functional assessment based on the Western Ontario Shoulder Instability Index (WOSI) and the Constant Score (CS) at minimum 5 years follow-up. Patient's demographics, sport activities, duration of surgery, the rate of recurrent dislocations, and specific complications related to the surgical technique were recorded as secondary variables.

RESULTS

There was a decrease of the WOSI in both groups, indicating a decrease of symptoms at follow-up compared to the preoperative level. There was no statistically significant difference between groups 1 and 2 for the total WOSI as well as for all subscales. There was an increase of the CS in both groups in all four items at follow-up compared to preoperatively, indicating an increase in shoulder function at follow-up. There was a statistically significant difference between groups 1 and 2 for the total CS, as well as for the items power, mobility, and activity, but not for pain. Most patients (n = 20) returned to their preoperative sports activity, 13 at the same level. However, seven patients who used to perform their sports competitively chose to perform their activity at a noncompetitive level after the Latarjet procedure. All were younger than 35 years of age. Six patients did not return to their preoperative sports activity. All except one were over 35 years of age. The duration of surgery ranged from 75 to 125 minutes with a mean ± SD of 94.23 ± 15.06 minutes for both groups with no significant difference between the groups (p = 0.117). None of the patients had intra- or postoperative complications related to the surgical procedure. Especially, no patient had recurrent dislocations of the affected shoulder following the Latarjet procedure.

CONCLUSION

The use of a PMFF is a safe technique for reconstruction of the CAL, which does not result in a longer surgery time or higher rate of complications. The reconstruction of the CAL during the modified Latarjet procedure may lead to better functional results in medium-term follow-up.

The Infinity-Lock System for Chronic Grade III AC Joint Dislocation: A Novel Technique, Rehabilitation Protocol and Short Term Results

Background: the choice of treatment of chronic grade III acromioclavicular (AC) joint dislocation is controversial. Several surgical techniques have been described in the literature, responding differently to nonoperative treatment. The aim of this study is to describe a modified technique of stabilizing an AC joint dislocation with the new Infinity-Lock Button System, in order to demonstrate that it is effective in optimizing outcomes and decreasing complications. Methods: this is a retrospective study of 15 patients who underwent surgical stabilization of the AC joint dislocation between 2018 and 2019, through modified surgical technique using the Infinity-Lock Button System. Active range of motion (ROM), Specific Acromio Clavicular Score (SACS) and Constant Score (CS) were evaluated preoperatively and postoperatively at last 18 months follow up. Patients rated their outcomes as very good, good, satisfactory, or unsatisfactory. Results: a total of twelve patients rated their outcome as very good and three as good; no patients were dissatisfied with surgery. The mean Constant Score increased from 38 points preoperatively to 95 postoperatively, the average SACS score decreased from 52 points preoperatively to 10 postoperatively, both significantly. No complications were detected. Conclusion: the described technique is effective for treatment of chronic grade III AC joint dislocation, resulting in elevated satisfaction ratings and predictable outcomes. Nevertheless, further longer term follow-up studies are required.

Shoulder Release and Tendon Transfer following Neonatal Brachial Plexus Palsy: Gains, Losses, and Midline Function

BACKGROUND

Shoulder release and tendon transfer is frequently performed to address persistent weakness from neonatal brachial plexus palsy. Although postoperative improvements in motion are well described, associated deficits are poorly documented, and functional assessments are lacking. Loss of ability to reach midline can occur with surgery and may result in impairment. The purpose of this study was to comprehensively assess the gains, losses, functional changes, and patient-reported outcome associated with the authors' surgical approach.

METHODS

Consecutive patients undergoing surgery with 2-year follow-up were included (n = 30). Prospectively recorded assessments by therapists were reviewed. Changes were assessed by t test and Wilcoxon rank sum (p < 0.05).

RESULTS

Active external rotation and abduction improved and internal rotation diminished. Aggregate modified Mallet score increased with improvements in all subscales, except that hand to spine was unchanged and hand to belly decreased. Functional assessment using the Brachial Plexus Outcome Measure revealed an increase of aggregate score, with no decline in any subscales. Improvements were in hand to back of head, forward overhead reach, holds plate with palm up, opening large container, and strings bead. Aggregate patient self-report of appearance and function increased (from 18 to 23). Loss of ability to reach midline occurred in three patients (10 percent) who had extended Erb or total palsy and preoperative limitations of internal rotation.

CONCLUSIONS

Secondary reconstruction rebalances shoulder motion by increasing external rotation and abduction and reducing internal rotation. In this study, a conservative surgical approach results in overall improvement in task-based abilities and self-reported outcomes and preservation of internal rotation within a functional range.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Optimal Management of Acromioclavicular Dislocation: Current Perspectives

Injuries to the acromioclavicular (AC) joint are common and mostly involve younger, male individuals. Whereas the majority of AC joint dislocations can be treated nonoperatively with a trial of immobilization, pain medication, cryotherapy, and physiotherapy, there are patients that do not respond well to conservative management and may require surgical treatment. Identifying and treating these patients according to the type and chronicity of AC joint dislocation is paramount. To date, a myriad of surgical techniques have been proposed to address unstable AC joint dislocations and are indicative of the uncertainty that exists in optimal management of these injuries. Historically research has focused on the restoration of the coracoclavicular ligament complex. However, recently the importance of the acromioclavicular capsule and ligaments has been emphasized. This review aims to provide the reader with an overview of current treatment strategies and research, as well as future perspectives.

Acromioplasty in the surgical operations of partial-thickness rotator cuff tears: A comprehensive review

The partial-thickness rotator cuff tears (PTRCTs) are known as a prevalent pathology, which cause inability mostly in athletes. So far, a number of treatments have been suggested depending on patient characteristics and size and location of the tears. Surgical repair in rotator cuff tears that include 50% or more of the tendon thickness is the accepted practice in the following failure of nonoperative treatment. In the surgical procedure, acromioplasty is known as a long-established component and used to modify the detrimental acromion morphology, which accounts for rotator cuff tearing. A range of trials has been reported that compare the results of surgical procedure with and without acromioplasty in patients undergoing rotator cuff repairs. According to the findings of 15 studies including ~1,500 patients, with mean age 60 years (range 5-80 years) and mean follow-up of 22 months (range 13-26 months) found by searching on Cochrane Register of Controlled Trials databases, Excerpta Medica/Embase, and Medline/PubMed, we revealed that acromioplasty cannot present an impressive effect on patient outcome scores at intermediate and short-term follow-ups. In fact, despite the theoretic advantages of acromioplasty in the setting of PTRCTs, it has reported little or no efficacy on outcomes of postoperative patients.

Irreparable Rotator Cuff Tears: A Biomechanical Comparison of Superior Capsuloligamentous Complex Reconstruction Techniques and an Interpositional Graft Technique

Background:

Irreparable rotator cuff tears lead to superior translation of the humeral head. Numerous surgical management options are available to treat the condition.

Purpose:

To compare superior capsule stability among different types of patch grafting in irreparable rotator cuff tears.

Methods:

Six cadaveric shoulders were tested in a custom-designed shoulder testing system. Superior translation of the humerus and subacromial contact pressure were quantified in an intact condition (condition 1), after cutting the supraspinatus tendon (condition 2), and after additionally cutting the superior capsuloligamentous complex (condition 3). The results were compared among 3 types of patch grafting, in which capsule reconstruction was achieved by glenoidal 3-point (condition 4) or 2-point (condition 5) fixation or by affixing a graft below the acromion (condition 6).

Results:

No significant difference in subacromial pressure was measured by reconstruction with 2 or 3 anchors compared with conditions 1 and 2 (P > .05). However, with 3-point fixation, lower levels of pressure were measured than with 2-point fixation. Moreover, superior translation values were lower with 3-point fixation; the same applied for values of the preserved capsule as compared with the torn capsule. In condition 6, a significant increase in pressure in the neutral position was documented (P < .05).

Conclusion:

The superior capsuloligamentous complex plays an important role in stabilizing the glenohumeral joint. The results suggest that with additional medial anchoring at the coracoid base, the depressing and centering effect of the superior complex can probably be regained in a more physiological way compared with a reconstructed capsule with 2 glenoid attachments or with an interpositional graft below the acromion.

Coracoacromial morphology: a contributor to recurrent traumatic anterior glenohumeral instability?

BACKGROUND

Although scapular morphology contributes to glenohumeral osteoarthritis and rotator cuff disease, its role in traumatic glenohumeral instability remains unknown. We hypothesized that coracoacromial and glenoid morphology would differ between healthy subjects and patients with recurrent traumatic anterior shoulder instability.

METHODS

Computed tomography scans of 31 cadaveric control scapulae and 54 scapulae of patients with recurrent traumatic anterior shoulder instability and Hill-Sachs lesions were 3-dimensionally reconstructed. Statistical shape modeling identified the modes of variation between the scapulae of both groups. Corresponding measurements quantified these modes in relation to the glenoid center (linear offset measures), defined by the best-fit circle of the inferior glenoid, or the glenoid center plane (angles), which bisects the glenoid longitudinally. Distances were normalized for glenoid size.

RESULTS

Compared with controls, the unstable coracoids were shorter (P = .004), with a more superior and medial offset of the tip (mean difference [MD], 7 and 3 mm, respectively; P < .001) and an origin closer to the 12-o'clock position (MD, 6°; P < .001). The unstable scapular spines originated closer to the 9-o'clock position (MD, 4°; P = .012), and the unstable acromions were more vertically oriented (MD, 6°; P < .001). The unstable glenoids had an increased height-width index (MD, 0.04; P = .021), had a flatter anterior-posterior radius of curvature (MD, 77 mm; P < .001), and were more anteriorly tilted (MD, 5°; P = .005).

CONCLUSIONS

Coracoacromial and glenoid anatomy differs between individuals with and without recurrent traumatic anterior shoulder instability. This pathologic anatomy is not addressed by current soft-tissue stabilization procedures and may contribute to instability recurrence.

ArthroPlanner: a surgical planning solution for acromioplasty

PURPOSE

We present a computer-assisted planning solution "ArthroPlanner" for acromioplasty based on 3D anatomical models, computed tomography and joint kinematic simulations.

METHODS

In addition to a standard static clinical evaluation (anamnesis, radiological examination), the software provides a dynamic assessment of the shoulder joint by computing in real time the joint kinematics from a database of activities of daily living. During motion, the precise bone resection (location and amount) is computed based on detected subacromial impingements, providing surgeons with precise information about the surgical procedure. Moreover, to improve the subjective reading of medical images, the software provides 3D measurement tools based on anatomical models assisting in the analysis of shoulder morphological features.

RESULTS

We performed an in vivo assessment of the software in a prospective randomized clinical study conducted with 27 patients beneficiating from the planning solution and a control group of 31 patients without planning. Postoperatively, patient's pain decreased, and the shoulder range of motion and the functional outcomes improved significantly and the rotator cuff healing rate was good for both groups without intergroup differences. The amount of bone resected at surgery was comparable between the groups. The percentage of remaining impingement after surgery was in average reduced to 51% without groups difference.

CONCLUSIONS

ArthroPlanner software includes all required materials (images data, 3D models, motion, morphological measurements, etc.) to improve orthopedists' performance in the surgical planning of acromioplasty. The solution offers a perfect analysis of the patient's anatomy and the ability to precisely analyze a dynamic mechanism to fully apprehend the patient's condition and to fulfill his/her expectations. The study however failed to detect any statistically significant difference in clinical outcomes and bone resection between the groups. Short-term clinical and radiological results were excellent in both groups.

Arthroscopic Transfer of the Conjoined Tendon-Coracoid Tip Complex for Anterior Shoulder Instability

In the treatment of anterior shoulder instability, there are various conditions in which a sling effect is needed to enhance anterior stability. The traditional Bristow-Latarjet procedure provides a sling effect but destroys or does not purposely protect the coracoacromial (CA) arch, which may result in superior instability. To preserve the CA arch and create a sling to enhance the anterior-inferior side of the shoulder, we introduce an arthroscopic technique to transfer the conjoined tendon-coracoid tip complex (CTCTC) with the intention to keep the CA ligament intact to the utmost. The indications for CTCTC transfer are patients younger than 45 years who participate in competitive sports, require forceful external rotation and abduction movements of the shoulder, and/or have capsule-ligament insufficiency. The main steps of this procedure include detaching the CTCTC, fashioning the coracoid tip to obtain a coracoid pillar, braiding the CTCTC, creating a glenoid tunnel and socket, placing a guide suture through the glenoid tunnel and subscapularis, passing the CTCTC through the subscapularis and into the glenoid socket, and performing suspension fixation of the CTCTC.

Arthroscopic Transfer of the Long Head of the Biceps Brachii for Anterior Shoulder Instability

In the treatment of anterior shoulder instability, there are various conditions in which a sling effect is needed to enhance anterior stability. The traditional Latarjet procedure provides a sling effect but destroys the coracoacromial arch, which may result in superior instability. To preserve the coracoacromial arch and create a sling to enhance the anterior-inferior side of the shoulder, we introduce an arthroscopic technique to transfer the long head of the biceps (LHB) brachii. Indications of LHB transfer are patients younger than 45 years of age who participate in competitive sports, require forceful external rotation and abduction movement of the shoulder, and/or have capsule-ligament insufficiency, as well as patients 45 years o or older who have combined SLAP lesions (type II or IV). The main steps of this procedure include detaching the LHB, retrieving and braiding the LHB, creating a glenoid tunnel, placing a guide suture through the subscapularis and glenoid tunnel, passing the LHB through the subscapularis and into the glenoid tunnel, and suspension fixation of the LHB.

Biomechanical comparison of acute Hill-Sachs reduction with remplissage to treat complex anterior instability

BACKGROUND

Acute Hill-Sachs reduction represents a potential alternative method to remplissage for the treatment of an engaging Hill-Sachs lesion. This study biomechanically compared the stabilizing effects of an acute Hill-Sachs reduction technique and remplissage.

METHODS

Six cadaveric shoulders were tested. For the acute Hill-Sachs lesion, a unique model was used to create a 30% defect, compressing the subchondral bone while preserving the articular surface. Five scenarios were tested: intact specimen, bipolar lesion, Bankart repair, remplissage with Bankart repair, and Hill-Sachs reduction technique with Bankart repair. The Hill-Sachs lesion was reduced through a lateral cortical window with a bone tamp, and the subchondral void was filled with bone cement.

RESULTS

At 90° of abduction and external rotation (ER), total translation was 11.6 ± 0.9 mm for the bipolar lesion. This was significantly reduced after remplissage (5.9 ± 1.1 mm; P < .001) and after Hill-Sachs reduction (4.7 ± 0.4 mm; P < .001). Compared with an isolated Bankart repair, the average ER loss after remplissage was 4° ± 4° (P = .65), and the average ER loss after Hill-Sachs reduction was 1° ± 3° (P = .99). Similar joint stability was conferred after both procedures, with minimal change in range of motion.

CONCLUSIONS

Remplissage may still be the best way to address chronic Hill-Sachs lesions; however, the reduction technique is a more anatomic alternative and may be a potential option for treating an acutely engaging Hill-Sachs lesion.

The Coracoacromial Ligament: Anatomy, Function, and Clinical Significance

The coracoacromial ligament (CAL) was first described as a pain generator by Dr Charles Neer in the early 1970s. Since that time, considerable controversy regarding CAL management during acromioplasty has persisted. This review aims to better understand the role of the CAL in shoulder physiology and pathology. Sixty-six articles from 1958 to 2016 were identified using an electronic search of PubMed, Cochrane Library, AccessMedicine, and MD Consult for case series as well as cohort and prospective studies. The authors used “coracoacromial ligament” and “coracoacromial veil” as medical subject headings (MeSH). In addition, reference lists from all identified articles were reviewed for studies that the search terms may have omitted. The CAL plays an important role in shoulder biomechanics, joint stability, and proprioception. Morphological variance of the CAL is evident throughout the literature. Age-dependent changes due to chronic stress and cellular degradation cause thickening and stiffening of the CAL that may contribute to a spectrum of shoulder pathology from capsular tightness to rotator cuff tear arthropathy and impingement syndrome. The CAL is an integral component of the coracoacromial arch. CAL release during acromioplasty remains controversial. Future clinical outcomes research should endeavor to advance the understanding of the CAL to refine clinical and intraoperative decision making regarding its management.

Relationship between acromial morphological variation and subacromial impingement: A three-dimensional analysis

Purpose: To evaluate the association of acromial morphology and subacromial impingement. Methods: Bilateral shoulder computed tomography was performed in 138 patients who received shoulder arthroscopy. Measured parameters included: acromial tilt (AT), modified acromial tilt (mAT), acromial slope (AS), acromiohumeral interval (AHI), lateral acromial angle (LAA), acromial index (AI), critical shoulder angle (CSA), acromial anterior protrusion (AAP), and acromial inferior protrusion (AIP). Acromial morphological characteristics were compared between groups. Side-to-side differences were assessed between affected and non-affected shoulders. Intra- and inter-observer agreements for each parameter were calculated. Results: AT (25.90 vs. 29.41°), mAT (18.88 vs. 22.64°), and AHI (5.46 vs. 6.47 mm) were significantly smaller in impinged patients. The impingement group demonstrated significantly larger AI (63.50 vs. 59.84%), CSA (31.78 vs. 28.74°), AAP (7.13 vs. 5.32 mm), and AIP (5.51 vs. 4.04 mm). Regarding side-to-side comparison, the acromial morphology was significantly different between the affected and non-affected shoulders in impinged patients, while the difference was slight and insignificant in control patients. All, except AS and LAA, measured parameters demonstrated good intra- and inter-observer agreements. Conclusions: Three-dimensional reconstructed CT scan is a reliable method to measure shoulder morphology. The acromial morphological variation is related with sub acromial impingement, however, the causal relationship of them should be further explored.

Identification of a Remodeled Neo-tendon After Arthroscopic Latarjet Procedure

PURPOSE

To macroscopically, histologically, and radiologically describe a time-dependent remodeling process of a neo-tendon or -ligament in the shoulder after the arthroscopic Latarjet procedure.

METHODS

During follow-up surgery after the arthroscopic Latarjet procedure, 17 shoulders in 16 patients were evaluated for a remodeled tendon-like structure. The mean overall follow-up period was 27.4 months. The mean time between the arthroscopic Latarjet procedure and revision was 11.6 months. All shoulders were evaluated with magnetic resonance imaging, and seven histologic specimens were obtained during revision surgery.

RESULTS

A distinct, oriented strand of tissue was found in 16 of 17 shoulders on revision surgery. Postoperative magnetic resonance imaging analyses showed a signal-free, longitudinal tendon-like structure originating at the tip of the acromion, traversing the space of the former subcoracoid bursa to attach in the course of the transposed conjoint tendon or the proximal short head of the biceps. Histologic analysis of seven specimens showed a characteristic timeline of remodeling.

CONCLUSIONS

A tendon- or ligament-like structure is remodeled between the anterior bottom tip of the acromion and the transposed coracoid process in a time-dependent manner after the arthroscopic Latarjet procedure.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Grade of coracoacromial ligament degeneration as a predictive factor for impingement syndrome and type of partial rotator cuff tear

BACKGROUND

The purpose of this study was to investigate the role of coracoacromial ligament degeneration and specific anatomic parameters in the etiology of partial-thickness rotator cuff tears.

MATERIALS AND METHODS

This study retrospectively assessed 96 patients (mean age, 50.1 years [17-76]; 34 men, 62 women) diagnosed with bursal-side and articular-side rotator cuff tears with a history of failed conservative treatment and persistent shoulder pain who underwent arthroscopic surgery. Video records of the surgery were used to evaluate the type of cuff tear, grade of coracoacromial ligament degeneration, and associated pathologic changes; preoperative magnetic resonance images were used to measure acromioglenoid angle, supraspinatus glenoid angle, and subacromial distance.

RESULTS

Most of the patients with articular-side tears demonstrated grade 0 and grade 1 coracoacromial ligament degeneration, whereas patients with bursal-side tears had grade 1 and grade 2. There was a significant positive correlation between the grade of coracoacromial ligament degeneration and bursal-side partial rotator cuff tears, whereas no correlation was observed with articular-side tears. There was no significant difference between bursal-side and articular-side partial cuff tears regarding acromioglenoid angle, supraspinatus glenoid angle, and subacromial distance.

CONCLUSIONS

Grade 1 and grade 2 coracoacromial ligament degeneration is a strong predictive factor for impingement syndrome in the etiology of bursal-side partial cuff tears and can guide the surgeon to consider ligament release and débridement or acromioplasty in these patients.

Rotator Cuff Repair: Is there any role for acromioplasty?

OBJECTIVES

Acromioplasty has been one of the most common techniques amongst orthopedic surgeries in the past decade. However, its efficacy in arthroscopic surgeries of rotator cuff repair is still debatable. The purpose of this study is to compare the arthroscopic rotator cuff repair with or without acromioplasty in patients with complete rotator cuff tear.

METHODS

In this prospective cohort study, patients with complete rotator cuff tear (acromion type II or III Bigliani) and a history of failure to the conservative treatment for at least 6 months were evaluated for eligibility. Patients, based on the time interval, were placed in one of two groups: arthroscopic rotator cuff repair with (RCR-A group) and without acromioplasty (RCR group). Patients were assessed for two years in term of pain intensity by VAS criteria and shoulder functional status by Quick-DASH, Constant score and simple shoulder test criteria.

RESULTS

In the baseline assessment, RCR-A group (34 patients) and RCR group (33 patients) were similar. Comparing patients in two groups in relation to SST, Quick-DASH and VAS scores preoperatively showed there is no significant difference between the two groups. The SST, Quick-DASH and VAS scores improved significantly in both groups at both the 6-month and 2-year follow-ups (all P < 0.001). The extent of progress in the functional scores was similar in both groups (P > 0.05).

CONCLUSION

Arthroscopic rotator cuff repair without acromioplasty may be as reliable and useful as conventional rotator cuff repair with acromioplasty. Thus, acromioplasty cannot be recommended as a routine technique in every rotator cuff repair.

Biomechanical Comparison of the Latarjet Procedure with and without Capsular Repair

Background

The purpose of this study was to determine if capsular repair used in conjunction with the Latarjet procedure results in significant alterations in glenohumeral rotational range of motion and translation.

Methods

Glenohumeral rotational range of motion and translation were measured in eight cadaveric shoulders in 90° of abduction in both the scapular and coronal planes under the following four conditions: intact glenoid, 20% bony Bankart lesion, modified Latarjet without capsular repair, and modified Latarjet with capsular repair.

Results

Creation of a 20% bony Bankart lesion led to significant increases in anterior and inferior glenohumeral translation and rotational range of motion (p < 0.005). The Latarjet procedure restored anterior and inferior stability compared to the bony Bankart condition. It also led to significant increases in glenohumeral internal and external rotational range of motion relative to both the intact and bony Bankart conditions (p < 0.05). The capsular repair from the coracoacromial ligament stump to the native capsule did not significantly affect translations relative to the Latarjet condition; however it did cause a significant decrease in external rotation in both the scapular and coronal planes (p < 0.005).

Conclusions

The Latarjet procedure is effective in restoring anteroinferior glenohumeral stability. The addition of a capsular repair does not result in significant added stability; however, it does appear to have the effect of restricting glenohumeral external rotational range of motion relative to the Latarjet procedure performed without capsular repair.

Biomechanical Effects of Acromioplasty on Superior Capsule Reconstruction for Irreparable Supraspinatus Tendon Tears

BACKGROUND

Acromioplasty is increasingly being performed for both reparable and irreparable rotator cuff tears. However, acromioplasty may destroy the coracoacromial arch, including the coracoacromial ligament, consequently causing a deterioration in superior stability even after superior capsule reconstruction.

PURPOSE/HYPOTHESIS

The purpose of this study was to investigate the effects of acromioplasty on shoulder biomechanics after superior capsule reconstruction for irreparable supraspinatus tendon tears. The hypothesis was that acromioplasty with superior capsule reconstruction would decrease the area of subacromial impingement without increasing superior translation and subacromial contact pressure.

STUDY DESIGN

Controlled laboratory study.

METHODS

Seven fresh-frozen cadaveric shoulders were evaluated using a custom shoulder testing system. Glenohumeral superior translation, the location of the humeral head relative to the glenoid, and subacromial contact pressure and area were compared among 4 conditions: (1) intact shoulder, (2) irreparable supraspinatus tendon tear, (3) superior capsule reconstruction without acromioplasty, and (4) superior capsule reconstruction with acromioplasty. Superior capsule reconstruction was performed using the fascia lata.

RESULTS

Compared with the intact shoulder, the creation of an irreparable supraspinatus tear significantly shifted the humeral head superiorly in the balanced muscle loading condition (without superior force applied) (0° of abduction: 2.8-mm superior shift [P = .0005]; 30° of abduction: 1.9-mm superior shift [P = .003]) and increased both superior translation (0° of abduction: 239% of intact [P = .04]; 30° of abduction: 199% of intact [P = .02]) and subacromial peak contact pressure (0° of abduction: 308% of intact [P = .0002]; 30° of abduction: 252% of intact [P = .001]) by applying superior force. Superior capsule reconstruction without acromioplasty significantly decreased superior translation (0° of abduction: 86% of intact [P = .02]; 30° of abduction: 75% of intact [P = .002]) and subacromial peak contact pressure (0° of abduction: 47% of intact [P = .0002]; 30° of abduction: 83% of intact [P = .0005]; 60° of abduction: 38% of intact [P = .04]) compared with after the creation of a supraspinatus tear. Adding acromioplasty significantly decreased the subacromial contact area compared with superior capsule reconstruction without acromioplasty (0° of abduction: 26% decrease [P = .01]; 30° of abduction: 21% decrease [P = .009]; 60° of abduction: 61% decrease [P = .003]) and did not alter humeral head position, superior translation, or subacromial peak contact pressure.

CONCLUSION

Superior capsule reconstruction repositioned the superiorly migrated humeral head and restored superior stability in the shoulder joint. Adding acromioplasty decreased the subacromial contact area without increasing the subacromial contact pressure.

CLINICAL RELEVANCE

When superior capsule reconstruction is performed for irreparable rotator cuff tears, acromioplasty may help to decrease the postoperative risk of abrasion and tearing of the graft beneath the acromion.

Continuous Loop Double Endobutton Reconstruction for Acromioclavicular Joint Dislocation

BACKGROUND

Current anatomic methods for reconstruction of the dislocated acromioclavicular (AC) joint show improved clinical results but continue to be associated with significant rates of fixation loss and complications, limiting more widespread use.

PURPOSE

To determine the long-term clinical and radiologic outcomes of a novel surgical technique using a closed-loop double Endobutton device to reconstruct both acute and chronic dislocations.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Between 2003 and 2012, a total of 35 patients (31 men, 4 women) at a mean age of 42 years (range, 25-70 years) were surgically treated for a Rockwood type III or greater AC joint dislocation with the described technique (26 chronic, 9 acute). Imbrication of the AC joint capsule and deltotrapezial fascia was performed in all patients. Biological bridging across the coracoclavicular (CC) interval was performed in all patients by use of coracoacromial (CA) ligament transfer in 28 patients and primary repair of the CC ligament in 7 patients. Complete follow-up information was obtained for 31 of 35 patients.

RESULTS

At a mean follow-up of 5.2 years (range, 27-144 months), the construct remained stable in all but 1 patient. The mean CC interval difference was 1.1 mm (range, -2.5 to 4.0 mm) and was <2 mm in 87% of patients. The mean Constant score was 98; the mean University of California, Los Angeles Shoulder Rating Scale score was 34; and the mean American Shoulder and Elbow Surgeons Shoulder Score was 98. Follow-up MRI evaluation in 10 patients consistently demonstrated a wide band of dense scar tissue between the coracoid and clavicle. No infections, fractures, or perioperative complications occurred.

CONCLUSION

Excellent results were obtained and maintained over long-term follow-up. The continuous loop device eliminated the possibility of knot slippage or breakage. MRI confirmed a robust healing response. The described technique resulted in outcomes that were significantly superior to historical reports of nonsurgical outcomes, and the technique can be recommended both for acute and chronic dislocations.

Reconstruction of the coracoacromial ligament during a modified Latarjet procedure: a case series

Background

The coracoacromial ligament (CAL) is an important restraint to superior shoulder translation. CAL release with the Latarjet procedure leads to increased superior humeral translation. Therefore, a surgical technique was developed to reconstruct the CAL during a modified Latarjet procedure.

Methods

Between May 2010 and July 2011, six patients (five were male, one was female; age 23–41 years) with chronic post-traumatic anterior shoulder instability were treated surgically with a modified congruent-arc Latarjet procedure (modLAT) with additional reconstruction of the CAL using a newly developed procedure, the pectoralis minor fascia flap (PMFF). Clinical follow-up was performed for up to 36 months, and patients were evaluated using a Rowe score.

Results

All six patients experienced chronic, post-traumatic anterior shoulder instability and had experienced multiple re-dislocations after initial treatment. The preoperative assessment showed a defect of the anterior glenoid in three cases, and the mean Rowe score was 16.67 (5–25). Open modLAT with PMFF resulted in a stable shoulder function with no re-dislocations. The Rowe score increased from 77.5 (65–90) at 12 weeks to 95 (90–100) at 12 months and plateaued thereafter. Operative duration was 95 min (78–112 min), and there were no intra- or postoperative complications. All patients returned to their preoperative sports activity, three at the same level.

Conclusion

The PMFF is a safe technique for reconstruction of the CAL during a modLAT procedure. Patients had improved shoulder function and no re-dislocations after the surgery.

Is acromioplasty necessary in the setting of full-thickness rotator cuff tears? A systematic review

BACKGROUND

The benefits of acromioplasty in treating rotator cuff disease have been debated. We systematically reviewed the literature regarding whether acromioplasty with concomitant coracoacromial (CA) release is necessary for the successful treatment of full-thickness rotator cuff tears.

MATERIALS AND METHODS

We identified randomized controlled trials that reported on patients who underwent rotator cuff repair with or without acromioplasty and used descriptive statistics to summarize the findings.

RESULTS

Four studies fulfilled the inclusion criteria. They reported on 354 patients (mean age, 59 years; range 3-81 years) with a mean follow-up of 22 months (range 12-24 months). There were two level-I and two level-II studies. Two studies compared rotator cuff repair with versus without acromioplasty, and two studies compared rotator cuff repair with versus without subacromial decompression (acromioplasty, CA ligament resection, and bursectomy). The procedures were performed arthroscopically, and the CA ligament was released in all four studies. There were no statistically significant differences in clinical outcomes between patients treated with acromioplasty compared with those treated without acromioplasty.

CONCLUSIONS

This systematic review of the literature does not support the routine use of partial acromioplasty or CA ligament release in the surgical treatment of rotator cuff disease. In some instances, partial acromioplasty and release of the CA ligament can result in anterior escape and worsening symptoms. Further research is needed to determine the optimum method for the operative treatment of full-thickness rotator cuff tears.

LEVEL OF EVIDENCE

Level I, systematic review of level I and II studies.

Rotator cuff biology and biomechanics: a review of normal and pathological conditions

The glenohumeral joint is a complex anatomic structure commonly affected by injury such as tendinopathy and rotator cuff tears. This review presents an up-to-date overview of research on tendon biology and structure, shoulder joint motion and stability, tendon healing, and current and potential future repair strategies. Recent studies have provided information demonstrating the serious impact on uninjured tissues after a rotator cuff tear or other cause of altered shoulder joint mechanics. Another major focus of recent research is biological augmentation of rotator cuff repair with the goal of successfully reinstating normal tendon-to-bone structure. To effectively treat shoulder pathologies, clinicians need to understand normal tendon biology, the healing process and environment, and whole shoulder stability and function.

Stabilisation for the disrupted acromioclavicular joint using a braided polyester prosthetic ligament

PURPOSE

To report outcomes of 21 men who underwent stabilisation for the disrupted acromioclavicular joint (ACJ) using a braided polyester prosthetic ligament.

METHODS

21 men aged 23 to 76 (mean, 43) years underwent stabilisation for the disrupted ACJ of Rockwood type 3 (n=12), type 4 (n=1), and type 5 (n=8) using a braided polyester prosthetic ligament.

RESULTS

The mean time from injury to surgery was 6.8 (range, 0-19) months. The mean follow-up duration was 30 (range, 7-67) months. The mean Constant Score was 86.8 (range, 62-100), and the mean individualised Constant Score was 88.5 (range, 68-100). The mean Oxford Shoulder Score was 43.1 (range, 28-48). The mean abduction power of the operated side was 82% (range, 31%-97%) that of the normal side. 20 patients were satisfied with the procedure. One patient was dissatisfied who developed scapulothoracic bursitis. One patient required arthroscopic subacromial decompression for impingement. One patient sustained a redislocation following a fall at 6 weeks and declined further surgery.

CONCLUSION

The braided polyester prosthetic ligament achieved good outcome for patients undergoing stabilisation for the disrupted ACJ.

Effect of Anterior Capsular Laxity on Horizontal Abduction and Forceful Internal Impingement in a Cadaveric Model of the Throwing Shoulder

BACKGROUND

Excessive anterior capsular laxity (elongation of the anterior capsular ligaments) causes shoulder subluxation during acceleration of the throwing motion, leading to a disabled throwing shoulder. Few biomechanical studies have investigated the relationship between anterior capsular laxity and internal impingement, another cause of the disabled throwing shoulder.

PURPOSE/HYPOTHESIS

The purpose of this study was to assess the effect of anterior capsular laxity on forceful internal impingement during the late cocking phase. The hypothesis was that excessive anterior shoulder laxity caused by elongation of the anterior capsular ligaments will increase the horizontal abduction angle to increase glenohumeral contact pressure.

STUDY DESIGN

Controlled laboratory study.

METHODS

Eight fresh-frozen cadaveric shoulders were tested with the shoulder abducted to 90° and at maximal external rotation to simulate the late cocking phase of the throwing motion. The angle of external rotation, anterior translation, angle of horizontal abduction, locations of the articular insertion of the rotator cuff tendons (supraspinatus and infraspinatus) on the greater tuberosity relative to the glenoid, and the glenohumeral contact pressure and area during internal impingement were measured. All data were compared between intact and elongated anterior capsule, which was created by repeatedly applying external rotational stretching.

RESULTS

Elongation of the anterior capsular ligaments was confirmed by the increase in glenohumeral external rotation and anterior translation after our stretching technique. Location data showed that the posterior half of supraspinatus tendon, the entire infraspinatus tendon, and the posterosuperior labrum were impinged between the greater tuberosity and glenoid. Maximal glenohumeral horizontal abduction (2.2% increase; P = .003) and glenohumeral contact pressure (27.3% increase; P = .04) were significantly increased in the shoulder joint with increased anterior capsular laxity as compared with the intact condition.

CONCLUSION

Increased anterior capsular laxity created by applying repetitive excessive external rotational torque significantly increased horizontal abduction and contact pressure in the glenohumeral joint. Concurrently, the supraspinatus and infraspinatus tendons and posterosuperior labrum were impinged between the greater tuberosity and glenoid.

CLINICAL RELEVANCE

Increased anterior capsular laxity may exacerbate forceful internal impingement during the late cocking phase of the throwing motion.

Biomechanical analysis of articular-sided partial-thickness rotator cuff tear and repair

BACKGROUND

Articular-sided partial-thickness rotator cuff tears are common injuries in throwing athletes. The superior shoulder capsule beneath the supraspinatus and infraspinatus tendons works as a stabilizer of the glenohumeral joint.

PURPOSE

To assess the effect of articular-sided partial-thickness rotator cuff tear and repair on shoulder biomechanics. The hypothesis was that shoulder laxity might be changed because of superior capsular plication in transtendon repair of articular-sided partial-thickness rotator cuff tears.

STUDY DESIGN

Controlled laboratory study.

METHODS

Nine fresh-frozen cadaveric shoulders were tested by using a custom shoulder-testing system at the simulated late-cocking phase and acceleration phase of throwing motion. Maximum glenohumeral external rotation angle, anterior translation, position of the humeral head apex with respect to the glenoid, internal impingement area, and glenohumeral and subacromial contact pressures were measured. Each specimen underwent 3 stages of testing: stage 1, with the intact shoulder; stage 2, after creation of articular-sided partial-thickness tears of the supraspinatus and infraspinatus tendons; and stage 3, after transtendon repair of the torn tendons by using 2 suture anchors.

RESULTS

Articular-sided partial-thickness tears did not significantly change any of the shoulder biomechanical measurements. In the simulated late-cocking phase, transtendon rotator cuff repair resulted in decreased maximum external rotation angle by 4.2° (P = .03), posterior shift of the humeral head (1.1-mm shift; P = .02), decreased glenohumeral contact pressure by 1.7 MPa (56%; P = .004), and decreased internal impingement area by 26.4 mm(2) (65%; P < .001) compared with values in the torn shoulder. In the acceleration phase, the humeral head shifted inferiorly (1.2-mm shift; P = .03 vs torn shoulder), and glenohumeral anterior translation (1.5-mm decrease; P = .03 vs torn shoulder) and subacromial contact pressure (32% decrease; P = .004 vs intact shoulder) decreased significantly after transtendon repair.

CONCLUSION

Transtendon repair of articular-sided partial-thickness supraspinatus and infraspinatus tears decreased glenohumeral and subacromial contact pressures at time zero; these changes might lead to reduced secondary subacromial and internal impingements and consequently progression to full-thickness rotator cuff tear. However, repair of the tendons decreased anterior translation and external rotation and changed the positional relationship between the humeral head and the glenoid.

CLINICAL RELEVANCE

Careful attention should be paid to shoulder laxity and range of motion when transtendon repair is chosen to treat articular-sided partial-thickness rotator cuff tears, specifically in throwing athletes.

Effect of posterior shoulder tightness on internal impingement in a cadaveric model of throwing

PURPOSE

Posterior shoulder tightness is common in throwing athletes, especially those with symptomatic shoulder internal impingement. The role of posteroinferior capsular contracture in the pathoetiologies of throwing-related injuries caused by shoulder internal impingement remains unclear. The purpose of this study was to assess effect of posterior shoulder tightness on internal impingement in a cadaveric model of throwing.

METHODS

Seven fresh-frozen cadaveric shoulders were tested with the shoulder abducted to 90° and at maximum external rotation to simulate the late cocking phase of throwing motion. Glenohumeral joint contact pressure and area through internal impingement, humeral head shift, and the maximum humeral rotation angle were measured. Posteroinferior capsular plication was performed to simulate posteroinferior capsular tightness and induce glenohumeral internal rotation deficit.

RESULTS

Following generation of simulated posteroinferior capsular tightness with resultant glenohumeral internal rotation deficit, glenohumeral contact pressure was significantly increased (P < 0.05), the impinged area of rotator cuff tendon was significantly decreased (P < 0.05), and the humeral head shifted posteriorly (P < 0.05) during shoulder internal impingement.

CONCLUSION

Excessive posteroinferior capsular tightness can cause forceful internal impingement of the shoulder at maximum external rotation position.

Biomechanical analysis of the modified Bristow procedure for anterior shoulder instability: is the bone block necessary?

BACKGROUND

Anterior shoulder instability with bone loss can be treated successfully with the modified Bristow procedure. Opinions vary regarding the role of the soft-tissue sling created by the conjoined tendon after transfer. Therefore, the aim of this study was to determine the effect of the modified Bristow procedure and conjoined tendon transfer on glenohumeral translation and kinematics after creating anterior instability.

METHODS

Eight cadaveric shoulders were tested with a custom shoulder testing system. Range-of-motion, translation, and kinematic testing was performed in 60° of glenohumeral abduction in the scapular and coronal planes under the following conditions: intact joint, Bankart lesion with 20% glenoid bone loss, modified Bristow procedure, and soft tissue-only conjoined tendon transfer.

RESULTS

A Bankart lesion with 20% bone loss resulted in significantly increased external rotation and translation compared with the intact condition (P < .05), as well as an anterior shift of the humeral head apex at all points of external rotation. Both the modified Bristow procedure and soft-tissue Bristow procedure maintained the increase in external rotation but resulted in significantly decreased translation (P < .05). There was no difference in translation between the 2 reconstructions.

CONCLUSIONS

The increase in external rotation suggests that the modified Bristow procedure does not initially restrict joint motion. Translational stability can be restored in a 20% bone loss model without a bone block, suggesting the importance of the soft-tissue sling.

Role of the superior shoulder capsule in passive stability of the glenohumeral joint

BACKGROUND

The shoulder capsule is the main static stabilizer of the glenohumeral joint. However, few studies specifically address the function of the superior shoulder capsule, which is usually damaged in patients with complete rotator cuff tears. Therefore, the purpose of this study was to determine the biomechanical contribution of the superior shoulder capsule to passive stability of the glenohumeral joint.

METHODS

Seven cadaveric shoulders were tested with a custom testing system. Glenohumeral translations, subacromial contact pressure, and glenohumeral external and internal rotations were quantified at 5°, 30°, and 60° of glenohumeral abduction. Data were compared among 3 conditions: (1) intact superior capsule, (2) after detaching the superior capsule from the greater tuberosity (tear model), and (3) after complete removal of the superior capsule from the greater tuberosity to the superior glenoid (defect model).

RESULTS

A tear of the superior capsule significantly (P < .05) increased anterior and inferior translations compared with those in the intact capsule. Creation of a superior capsular defect significantly (P < .05) increased glenohumeral translation in all directions, subacromial contact pressure at 30° of glenohumeral abduction, and external and internal rotations compared with those of the intact capsule.

CONCLUSION

The superior shoulder capsule plays an important role in passive stability of the glenohumeral joint. A tear in the superior capsule at the greater tuberosity, which may be seen with partial rotator cuff tears, increased anterior and inferior translations. A defect in the superior capsule, seen in massive cuff tears, increased glenohumeral translations in all directions.

The role of acromioplasty for rotator cuff problems

Acromioplasty is a well-described technique used throughout the wide spectrum of treatment options for shoulder impingement and rotator cuff pathology. Several randomized prospective studies have described clinical outcomes that are statistically similar when comparing patients undergoing rotator cuff repair either with or without concomitant acromioplasty. This article reviews the current evidence for use of acromioplasty in patients with subacromial impingement syndrome and during arthroscopic rotator cuff repair. Despite recently published studies, more long-term data, especially with regard to failure rates and return-to-surgery rates over time, are needed to better determine the role of acromioplasty.

Effect of excessive contralateral trunk tilt on pitching biomechanics and performance in high school baseball pitchers

BACKGROUND

There is a growing number of pitching-related upper extremity injuries among young baseball pitchers; however, there is a lack of data on the identification of injury prevention strategies, particularly the prevention of injuries through the instruction/modification of technique. The identification of technical parameters that are associated with increased joint loading is needed.

PURPOSE

To investigate the effects of excessive contralateral trunk tilt, a common technique identifiable by video observation, on pitching biomechanics and performance in high school baseball pitchers. The hypothesis was that this strategy is associated with greater joint loading and poor pitching performance.

STUDY DESIGN

Descriptive laboratory study; Level of evidence, 3.

METHODS

The 3-dimensional pitching biomechanics, ball speed, and frontal view of the pitching technique from 72 high school baseball pitchers were captured on video and analyzed. The videos were reviewed to determine if the pitcher's trunk was excessively contralaterally tilted at the instant of maximal shoulder external rotation by examining whether the side of the pitcher's head ipsilateral to the throwing limb deviated by more than a head width from a vertical line passing through the pitcher's stride foot ankle. Upper extremity kinetics and upper extremity/trunk kinematics between pitchers with and without excessive contralateral trunk tilt were compared using independent t tests.

RESULTS

Compared with pitchers who did not demonstrate excessive contralateral trunk tilt, those with excessive contralateral trunk tilt pitched at a higher ball speed (mean, 32.6 ± 2.2 vs 31.1 ± 2.9 m/s, respectively; P = .019) and experienced a greater elbow proximal force (mean, 103.9 ± 12.7 vs 93.2 ± 13.9 %weight, respectively; P = .001), shoulder proximal force (mean, 104.8 ± 14.1 vs 94.3 ± 15.5 %weight, respectively; P = .004), elbow varus moment (mean, 4.29 ± 0.73 vs 3.84 ± 0.8 %height*weight, respectively; P = .017), and shoulder internal rotation moment (mean, 4.21 ± 0.71 vs 3.75 ± 0.78 %height*weight, respectively; P = .011). Pitchers with excessive contralateral trunk tilt demonstrated less upper torso flexion at stride foot contact, less upper torso rotation, and greater upper torso contralateral flexion at maximal shoulder external rotation and ball release (P < .05).

CONCLUSION

Excessive contralateral trunk tilt is a strategy that is associated with higher ball speeds and increased joint loading.

CLINICAL RELEVANCE

Pitching with excessive contralateral trunk tilt, which can be identified through screening of the pitching technique, is associated with a benefit in performance and increased joint loading. Future study is warranted to determine if this strategy should be encouraged or discouraged by baseball coaches.

Arthroscopic anatomy of the subdeltoid space

From the first shoulder arthroscopy performed on a cadaver in 1931, shoulder arthroscopy has grown tremendously in its ability to diagnose and treat pathologic conditions about the shoulder. Despite improvements in arthroscopic techniques and instrumentation, it is only recently that arthroscopists have begun to explore precise anatomical structures within the subdeltoid space. By way of a thorough bursectomy of the subdeltoid region, meticulous hemostasis, and the reciprocal use of posterior and lateral viewing portals, one can identify a myriad of pertinent ligamentous, musculotendinous, osseous, and neurovascular structures. For the purposes of this review, the subdeltoid space has been compartmentalized into lateral, medial, anterior, and posterior regions. Being able to identify pertinent structures in the subdeltoid space will provide shoulder arthroscopists with the requisite foundation in core anatomy that will be required for challenging procedures such as arthroscopic subscapularis mobilization and repair, biceps tenodesis, subcoracoid decompression, suprascapular nerve decompression, quadrangular space decompression and repair of massive rotator cuff tears.

An overview of shoulder instability and its management

The assessment and management of patients with instability of the shoulder joint can be challenging, due to the varying ways patients present, the array of different classification systems, the confusing terminology used and the differing potential management strategies. This review article aims to provide a clear explanation of the common concepts in shoulder instability and how they relate to the assessment and management of patients.

There are sections covering the mechanisms of shoulder stability, the clinical assessment of patients and imaging techniques. Beyond that there is a discussion on the common classifications systems used and the typical management options.

Some patients fall into reasonably well defined categories of classification and in these cases, the management plan is relatively easy to define. Unfortunately, other patients can elude simple classification and in these instances their management requires very careful consideration. Further research may help to facilitate a better understanding of management of the patients in this latter group.

Use of magnetic resonance arthrography to compare clinical features and structural integrity after arthroscopic repair of bursal versus articular side partial-thickness rotator cuff tears

BACKGROUND

There has been no study using magnetic resonance arthrography (MRA) to compare clinical features and structural integrity after arthroscopic repair of bursal and articular side partial-thickness rotator cuff tears (PTRCTs).

HYPOTHESIS

The 2 groups studied, which consisted of patients who underwent arthroscopic repair for either the articular side or the bursal side, would show significant improvement in overall outcomes after surgery, even though clinical outcomes and structural integrity would not be significantly different. It was thought that the incidence of preoperative positive impingement signs and protruded spurs on the acromion undersurface would be higher in patients with a bursal side tear.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

The current study consisted of 83 patients who underwent arthroscopic repair for either articular side (group A; n = 29) or bursal side (group B; n = 54) PTRCT and who were available at the 2-year follow-up. Clinical outcomes were compared by use of the Neer impingement sign, visual analog scale for pain, Simple Shoulder Test, University of California Los Angeles score, and American Shoulder and Elbow Surgeons score. At 6 months after surgery, MRA was used to assess structural integrity.

RESULTS

At 2-year follow-up, both groups showed significant improvement in pain and shoulder function scores, even though there was no significant difference between groups. The retear rate on follow-up MRA was not significantly different between group A (8%) and B (11%). Patients in group B, compared with group A, showed a higher incidence of the preoperative impingement sign (89% vs 52%, respectively; P = .004), protruded spur on the acromion undersurface (69% vs 0%, respectively; P < .001), and concomitant acromioplasty (93% vs 24%, respectively; P < .001).

CONCLUSION

Both articular and bursal side PTRCTs showed significant functional improvements after arthroscopic repair. The bursal side tears had a higher incidence of impingement sign at preoperative examination and more often had a protruded spur on the acromion undersurface.

Anterior shoulder dislocation increases the propensity for recurrence: a cadaveric study of the number of dislocations and type of capsulolabral lesion

BACKGROUND

The number of anterior shoulder dislocations that predispose to recurrence is unknown; some clinicians recommend surgical repair after the initial episode and others after multiple recurrences. The purpose of this study was to quantify the forces during successive anterior dislocations of cadaveric shoulders and to inspect the capsule and labrum afterwards, in order to assess the propensity for recurrence.

MATERIALS AND METHODS

Twenty-two human cadaveric shoulders were tested using a custom cadaveric shoulder dislocation device with simulated muscle loading. Each was positioned in the apprehension position and the humerus was moved in horizontal abduction until the shoulder dislocated. The joint reaction force was measured, as was the force that developed passively in the pectoralis major muscle. Following 3 successive dislocations, each was inspected for anterior capsulolabral lesions.

RESULTS

There was a significant decrease in force after the second dislocation. In 11, there was no labral avulsion and a significant decrease in force after the first dislocation. In the other 11, there was a labral avulsion and a significant decrease in force after the second dislocation.

CONCLUSION

Two successive anterior shoulder dislocations may increase propensity for recurrence; but this is influenced by the type of capsulolabral lesion that occurs. No labral avulsion, likely a result of capsular stretching, may be a worse prognostic finding than labral avulsion after the initial episode.