Subscapularis dysfunction following anterior surgical approaches to the shoulder

Is the Subscapularis Function Preserved after the Latarjet Procedure? A Quantitative Analysis Using Positron Emission Tomography

Backgroud

In the Latarjet procedure, the subscapularis is divided at the superior two-thirds junction. It has been believed that this subscapularis split approach resulted in better internal rotation strength rather than an L-shaped subscapularis tenotomy. However, there are few studies demonstrating the preserved function of the subscapularis after the Latarjet procedure. The aim of the present study was to clarify the subscapularis activity using positron emission tomography (PET) in patients after the Latarjet procedure.

Methods

Six men who had undergone the Latarjet procedure were enrolled. The internal rotation exercise with elastic bands was performed with the arm at 0° and 90° of abduction. After the exercises, the patients had an intravenous injection of fluorine 18 fluorodeoxyglucose (18F FDG). Each PET image was fused to the corresponding computed tomography image to calculate the standardized uptake value (SUV). The internal rotation muscle strength was measured by a dynamometer.

Results

At 0° of abduction, the subscapularis SUVs of the involved side were significantly lower than those of the uninvolved side (p = 0.010), although there was no significant difference at 90° of abduction. The SUVs of the involved subscapularis were significantly lower at 0° of abduction than at 90° (p = 0.034). The internal rotation strength of the involved side was 81.1% ± 12.1% of the uninvolved side at 0° of abduction.

Conclusions

After the Latarjet procedure with the subscapularis split approach, subscapularis activity was well preserved at 90° of abduction. However, internal rotation strength was reduced by 19%.

Does the subscapularis repair affect the clinical outcome after primary reverse shoulder arthroplasty?

BACKGROUND

Reverse shoulder arthroplasty is an established procedure for patients with rotator cuff tear arthropathy. However, the repair of the subscapularis tendon remains a controversial and frequently discussed topic. This prospective randomized study was conducted to evaluate the clinical benefit of the subscapularis repair after reverse shoulder arthroplasty.

METHODS

Fifty patients (36 female and 14 male) were randomized and assigned to either the "repaired" (rep) or the "not repaired" (nrep) cohort. Intraoperatively, the subscapularis tendon was reattached in the rep cohort with 4 tendon-to-tendon sutures, whereas no repair was performed in the nrep cohort. The Constant-Murley Score (CS) and the range of motion were evaluated preoperatively as well as 12 and 36 months postoperatively. The Subjective Shoulder Value and the Lift-off test were performed 36 months postoperatively. The postoperative subscapularis integrity was assessed sonographically.

RESULTS

Twelve months postoperatively the rep cohort presented better results in the CS (rep: 71 vs. nrep: 66, P = .037). The normalized CS was 80% in the rep cohort and 75% in the nrep cohort (P = .114). At our last follow-up after 36 months, we did not find significant differences between the rep cohort and the nrep cohort in the CS (rep: 76 vs. nrep: 75, P = .285) and normalized CS (rep: 91% vs. nrep: 91%, P = .388). Concerning internal rotation (in points), the rep cohort achieved better results than the nrep cohort (rep: 7.3 vs. nrep: 6.6, P = .040). Flexion (rep: 145° vs. nrep: 151°, P = .826), abduction (rep: 135° vs. nrep: 137°, P = .816), external rotation (rep: 34° vs. nrep: 37°, P = .817), and the Subjective Shoulder Value (rep: 81% vs. nrep: 77%, P = .398) presented no significant differences between the cohorts. The ultrasound examination after 36 months displayed an intact tendon in 70%.

CONCLUSIONS

Although the subscapularis repair affects the postoperative internal rotation positively, there were no differences in midterm follow-up concerning the overall results after reverse total shoulder arthroplasty. Further, the external rotation is not affected by the repair of the subscapularis tendon.

[Translated article] Latarjet procedure for shoulder instability: Implications in the innervation of the subscapularis muscle

INTRODUCTION

Our aim was to describe whether Latarjet's technique affects subscapularis muscle innervation.

MATERIALS AND METHODS

We studied 12 embalmed shoulders. Subscapularis muscle innervation pattern was registered. Dimensions of the subscapularis at the glenohumeral joint line and the nerves entry point were measured. Horizontal distances from the nerves to the glenohumeral joint line as well as vertical ones to the split were measured before and after Latarjet procedure. A safe zone for the split was designed to avoid damage to subscapularis innervation.

RESULTS

Subscapularis muscle is innervated by three principal branches: upper, middle, and inferior subscapularis nerves. No statistical differences were found between innervation distances before and after Latarjet procedure. To perform subscapularis split along the muscle safe zone, two thirds' proportions throughout all the split must be maintained.

CONCLUSIONS

Subscapularis muscle has a triple innervation and was not altered after Latarjet procedure. Therefore, Latarjet technique seems to respect subscapularis muscle innervation if its split is placed through the subscapularis muscle safe zone.

Latarjet procedure for shoulder instability: Implications in the innervation of the subscapularis muscle

INTRODUCTION

Our aim was to describe whether Latarjet's technique affects subscapularis muscle innervation.

MATERIALS AND METHODS

We studied 12 embalmed shoulders. Subscapularis muscle innervation pattern was registered. Dimensions of the subscapularis at the glenohumeral joint line and the nerves entry point were measured. Horizontal distances from the nerves to the glenohumeral joint line as well as vertical ones to the split were measured before and after Latarjet procedure. A safe zone for the split was designed to avoid damage to subscapularis innervation.

RESULTS

Subscapularis muscle is innervated by three principal branches: upper, middle, and inferior subscapularis nerves. No statistical differences were found between innervation distances before and after Latarjet procedure. To perform subscapularis split along the muscle safe zone, two thirds' proportions throughout all the split must be maintained.

CONCLUSIONS

Subscapularis muscle has a triple innervation and was not altered after Latarjet procedure. Therefore, Latarjet technique seems to respect subscapularis muscle innervation if its split is placed through the subscapularis muscle safe zone.

Diagnostic Performance of Belly-Press Angle in Predicting the Severity of Subscapularis Tear

BACKGROUND

Neglected partial subscapularis tears often cause functional impairment even after repair of the supraspinatus and infraspinatus tear is done. Numerous physical examinations for detecting partial subscapularis tears have been described in previous studies.

PURPOSE

To analyze the relationship between the preoperative clinical features and the severity of a partial subscapularis tear and to provide diagnostic clues for patients requiring subscapularis repair.

STUDY DESIGN

Cohort study (Diagnosis); Level of evidence, 2.

METHODS

This retrospective study included 286 patients who underwent arthroscopic shoulder surgery between 2020 and 2022. Preoperative clinical features, including range of motion, functional scores, muscle strength ratio, modified belly-press test (measuring belly-press angle), and bear-hug test, were collected. Magnetic resonance imaging (MRI) evaluation was done according to the Yoo and Rhee classification. Types of subscapularis tear, supraspinatus lesion, and biceps lesion were recorded during arthroscopic surgery. A comparison of preoperative clinical features between the no-repair group (type 2A or less) and surgical repair group (type 2B or more) was done. The optimal cutoff value of the belly-press angle was determined and the diagnostic performance of the belly-press angle, bear-hug test, and MRI were evaluated using the receiver operating characteristic curve.

RESULTS

Among 286 patients, 189 (66.1%) had subscapularis tears with type 2A or more. There was a significant difference in muscle strength ratio of the belly-press (P < .001), belly-press angle (P < .001), and bear-hug test (P < .001) between the no-repair group (type 2A or less) and the surgical repair group (type 2B or more). With a belly-press angle of 15° as a new cutoff value, the modified belly-press test showed 67.6% sensitivity, 73.9% specificity, and 69.6% accuracy in detecting type 2B or higher subscapularis tear.

CONCLUSION

Patients with type 2A and 2B subscapularis tears (according to the Yoo and Rhee classification) showed differences in belly-press strength ratio, belly-press angle, and bear-hug test. The cutoff value of the 15° belly-press angle showed an accuracy of 69.6% in detecting subscapularis tears with type 2B or higher.

Multidirectional instability of the shoulder: surgical techniques and clinical outcome

Multidirectional instability of the shoulder has a complex pathoanatomy. It is characterized by a redundant glenohumeral capsule and increased joint volume. Subtle clinical presentation, unclear trauma history and multifactorial etiology poseses a great challenge for orthopedic surgeons in terms of diagnosis. Generally accepted therapeutic approach is conservative and the majority of patients achieve good results with rehabilitation. In patients who are symptomatic despite appropriate rehabilitation, surgical intervention may be considered. Good results have been obtained with open inferior capsular surgery, which has historically been performed in these patients. In recent years, advanced arthroscopic techniques have taken place in this field, and similar results compared to open surgery have been obtained with the less-invasive arthroscopic capsular plication procedure.

Anterior glenoid bone reconstruction and anterior latissimus transfer for failed Latarjet associated with irreparable subscapularis tear

Background

Management of combined persistent anterior glenoid bone deficiency with irreparable subscapularis tear can be very complicated and challenging especially if associated with arthritis. The objective of this study was to report the outcome of combined reconstruction of the anterior glenoid with bone autograft or allograft with additional anterior latissimus transfer to reconstruct irreparable subscapularis tear with or without humeral head replacement.

Methods

Nineteen patients (average age 29 years old) who underwent open anterior glenoid bone reconstruction with iliac crest bone autograft or ostechondral bone allograft (distal tibia or glenoid allograft), with anterior latissimus transfer to reconstruct irreparable subscapularis tear with or without humeral head replacement were included in this study. Outcome measures included preoperative and postoperative pain score, visual analog scale, Subjective Shoulder Value, American Shoulder and Elbow Surgeons score, and Constant Score.

Results

Out of the 19 patients, 5 patients underwent humeral resurfacing arthroplasty. Anterior glenoid bone reconstruction was performed with iliac crest bone autograft in 8 patients, glenoid osteochondral allograft in 7 patients, and tibial plafond in 4 patients. At mean 31-month follow-up of (13-63 months), 15 patients (79%) considered their shoulder stable and were able to return to their work and 14 (74%) patients returned to their sport activity. Redislocation had occurred in 1 of the 18 shoulders (5%), subluxation had occurred in 3 patients (16%) of the shoulders and apprehension was reported for 4 patients, 21% of the operated shoulders. All outcome measures showed significant improvement compared to before surgery. No intraoperative or immediate postoperative complications were observed. Four patients (21%) had to be revised to reverse shoulder arthroplasty.

Conclusion

The combination of anterior latissimus transfer, anterior glenoid bone grafting with or without humeral head resurfacing is an effective salvage surgical reconstruction that can stabilize shoulders in the setting of recurrent anterior instability after a failed Latarjet with an irreparable subscapularis tear. This could be a potential alternative reconstruction option that might be offered to patients with this difficult problem. Long-term outcome is needed to better evaluate the validity of this technique.

Subscapularis management during open Latarjet procedure: does subscapularis split versus tenotomy matter? A systematic review and meta-analysis

BACKGROUND

The purpose of this study was to systematically review the literature to ascertain the clinical outcomes of the open Latarjet (OL) procedure using either a subscapularis-split (SS) or subscapularis tenotomy (ST) via a deltopectoral (DP) approach.

METHODS

Two independent reviewers performed a literature search using the PubMed, Embase, and Scopus databases according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines. Only studies reporting on outcomes of the OL procedure via a DP approach comparing both SS and ST were considered for inclusion. Meta-analysis to compare clinical outcomes was performed using RevMan software.

RESULTS

Our search found 5 studies that met our inclusion criteria, including 615 shoulders (80.8% male patients), with an average age of 27.8 ± 12.6 years (range, 15-79 years) and mean follow-up period of 50.1 ± 29.4 months (range, 12-180 months). A total of 410 shoulders and 205 shoulders underwent the OL procedure via a DP approach using the ST technique and the SS technique, respectively, with both techniques resulting in significant increases in the Rowe score postoperatively (P < .0001 for both). Additionally, significantly higher postoperative Constant scores were observed in patients who underwent the OL procedure via an SS technique vs. those in the ST group (91.8 ± 7.2 vs. 79.6 ± 16.1, P < .0001). However, meta-analysis showed nonsignificantly higher postoperative Rowe and American Shoulder and Elbow Surgeons scores in patients who underwent the OL procedure via an SS technique vs. those in the ST group (96.1 ± 2.6 vs. 86.4 ± 7.6 [P = .57] and 91.6 ± 1.3 vs. 80.6 ± 25.5 [P = .47], respectively). Furthermore, meta-analysis showed that significantly more patients in the ST group had positive lift-off test results (10.0%) when compared with the SS group at final follow-up (2.7%, P = .01). However, meta-analysis indicated that the rate of recurrent instability was trending toward significance in favor of the SS group (0% vs. 11.7%, P = .07).

CONCLUSION

Our systematic review established that in cases of OL procedures being carried out via a DP approach, the SS technique results in significantly better functional outcome measures and significantly lower rates of subscapularis insufficiency when compared with an L-shaped ST technique at medium-term follow-up. Furthermore, there were lower rates of recurrent instability that were trending toward significance in favor of the SS technique.

Dislocation Arthropathy of the Shoulder

Glenohumeral osteoarthrosis (OA) may develop after primary, recurrent shoulder dislocation or instability surgery. The incidence is reported from 12 to 62%, depending on different risk factors. The risk of severe OA of the shoulder following dislocation is 10 to 20 times greater than the average population. Risk factors include the patient’s age at the first episode of instability or instability surgery, bony lesions, and rotator cuff tears. For mild stages of OA, arthroscopic removal of intraarticular material, arthroscopic debridement, or arthroscopic arthrolysis of an internal rotation contracture might be sufficient. For severe stages, mobilization of the internal rotation contracture and arthroplasty is indicated. With an intact rotator cuff and without a bone graft, results for anatomical shoulder arthroplasty are comparable to those following primary OA. With a bone graft at the glenoidal side, the risk for implant loosening is ten times greater. For the functional outcome, the quality of the rotator cuff is more predictive than the type of the previous surgery or the preoperative external rotation contracture. Reverse shoulder arthroplasty could be justified due to the higher rate of complications and revisions of non-constrained anatomic shoulder arthroplasties reported. Satisfactory clinical and radiological results have been published with mid to long term data now available.

Failed Latarjet Treated With Full Arthroscopic Eden-Hybinette Procedure Using Two Cortical Suture Buttons Leads to Satisfactory Clinical Outcomes and Low Recurrence Rate

PURPOSE

To report clinical and radiologic outcomes of arthroscopic Eden-Hybinette using 2 cortical suture buttons in a series of patients with previous failed Latarjet and persistent glenoid bone loss.

METHODS

Between 2015 and 2019, patients with recurrent anterior instability after failed Latarjet underwent arthroscopic Eden-Hybinette procedure using 2 cortical buttons for graft fixation. Exclusion criteria were open and primary Eden-Hybinette and less than one year follow-up. Functional assessment was performed using Rowe and Walch-Duplay scores, subjective shoulder value, visual analog scale, and degree of satisfaction. Iliac crest bone graft placement and healing were assessed postoperatively with computed tomography imaging.

RESULTS

A total of 17 patients with a mean age of 28 years (range, 21-43 years) at time of revision were included. The mean glenoid bone loss was 23% (range, 18%-42%). Medium or deep Hill-Sachs lesion (Calandra 2 and 3) was present in 65% of cases. At a mean follow-up of 3 ± 1.6 years, all but 1 patient (94%) considered their shoulder stable, and 15 patients (88%) were satisfied or very satisfied. The subjective shoulder value increased from 51% to 87% (P < .05), the Walch-Duplay increased from 23 to 86 points (P < .05), and Rowe scores improved from 30 to 92 points (P < .05). Apprehension was still positive in 3 patients (17.6%), with this percentage being greater in the presence of Hill-Sachs Calandra 3 (P = .02). Postoperative computed tomography scans showed optimal bone autograft position in all patients (below the glenoid equator and flush to the glenoid rim). Iliac crest bone graft healed to the anterior glenoid neck in 16 shoulders (94%). The rate of recurrent instability was 11.7% but only 1 patient required revision surgery (5.8%).

CONCLUSIONS

Arthroscopic Eden-Hybinette using 2 cortical buttons leads to satisfactory clinical outcomes and a low recurrence rate after failed Latarjet, allowing successful reconstruction of the anterior glenoid rim and simultaneous treatment of capsular deficiency and humeral bone loss.

LEVEL OF EVIDENCE

Therapeutic, level IV, retrospective case series.

Posterior-approach total shoulder arthroplasty: a case series with a minimum of 2-year outcomes

BACKGROUND

A posterior approach to shoulder arthroplasty has been described that may improve exposure to the retroverted glenoid and spare the rotator cuff. The purpose of this study was to evaluate posterior total shoulder arthroplasty (PTSA) at a minimum of 2 years.

METHODS

Between September 2016 and October 2017, 28 patients (30 shoulders) who underwent PTSA were retrospectively identified. Patients were monitored at baseline and at 6 weeks, 3 months, 6 months, 1 year, and a minimum of 2 years after surgery for range of motion, American Shoulder and Elbow Surgeons (ASES) and Simple Shoulder Test scores, radiographic outcomes, complications, and patient satisfaction. Radiographs were assessed for head height, neck-shaft angle, humeral head centering, and the presence or absence of glenoid-component cement lines. Repeated-measures analysis-of-variance models were implemented to compare the means for each outcome variable over time.

RESULTS

Of the 28 patients (30 shoulders), 24 patients (26 shoulders) (87%) were available for follow-up at a minimum of 2 years (average, 31.2 months; range, 23-40 months). At latest follow-up, the average ASES pain score was 45.2 (standard deviation [SD], 10.9; range, 20-50; 95% confidence interval [CI], 40.8-49.6); average ASES function score, 42.3 (SD, 8.9; range, 21.7-50; 95% CI, 38.7-45.8); average ASES total score, 87.5 (SD, 18.8; range, 31.7-100; 95% CI, 79.8-95.1); and average Simple Shoulder Test score, 10.2 (SD, 2.0; range, 5-12; 95% CI, 9.4-11.0). Average forward flexion was 164° (SD, 13.9°; range, 130°-180°; 95% CI, 158.3°-170.4°); average external rotation, 78° (SD, 9.2°; range, 55°-90°; 95% CI, 74.3°-82.3°); and average internal rotation, T10 (SD, 2; range, L3 to T6; 95% CI, T10 to T8). The average head height was 0.86 mm above the greater tuberosity (range, -6.5 to 6.9 mm), the average neck-shaft angle was 128° (range, 113°-148°), and the average implant placement was 0.12 mm superior to the center of the neck cut (range, -3.3 to 3.5 mm). Six implants were considered malpositioned based on the criterion of >5 mm of head height above or below the tuberosity or >2 mm off-center. Glenoid cement lines were present in 7 shoulders. Two patients experienced complications: 1 patient had symptomatic glenoid loosening 29 months postoperatively that required revision to an anterior reverse total shoulder arthroplasty, and 1 patient had postoperative weakness that resolved by 6 months.

CONCLUSION

PTSA is safe and efficacious at 2 years, spares the rotator cuff, and may improve early postoperative function. PTSA is more easily performed with stemless arthroplasty. Challenges with creation of the humeral head osteotomy and identification of the center of the cut humeral head surface can affect the accuracy of implant positioning. Further improvements in technique will likely improve the feasibility of this approach.

Full Arthroscopic Eden-Hybinette Procedure Using 2 Cortical Suture Buttons for the Reconstruction of Anteroinferior Glenoid Defects

Therapeutic management of recurrent anterior shoulder instability with an anterior glenoid defect and a Hill-Sachs lesion requires a bone graft to restore the width of the glenoid. The Latarjet procedure is the most popular technique but an iliac crest bone graft is preferred when the coracoid process is dysplastic or too short or after failure of Latarjet or Bristow-Latarjet. The purpose of this manuscript is to describe a full arthroscopic Eden-Hybinette-guided technique with 2 cortical suture buttons for bone graft fixation. This procedure allows reconstruction of severe glenoid bone defects and treatment of concomitant capsulolabral lesions and humeral bone loss, while preserving the subscapularis muscle. In addition, the use of 2 cortical buttons for bone graft fixation simplify graft transport and positioning, provides good control of the rotation, improving healing of the iliac crest bone graft to the anterior glenoid rim.

Single-row vs. double-row refixation of the subscapularis tendon after primary anatomic shoulder arthroplasty

BACKGROUND

The postoperative integrity of the subscapularis tendon after primary anatomical shoulder arthroplasty has a significant effect on postoperative results. A transosseus Single Row Refixation technique (SRR) has shown up to 30% of partial tears in literature, a modified Double Row Refixation technique (DRR) has biomechanically shown a significantly reduced tear rate, but is yet to be proven in a clinical setting. Thus, we compared the SRR to the DRR technique using clinical outcome parameters and ultrasound examination.

MATERIALS AND METHODS

36 patients (40 shoulders; 20f, 16 m; øage: 66 years) were included in our retrospective cohort study. 20 shoulders were treated with the SRR technique (12f, 8 m; FU ø40.9 months) and 20 with the DRR technique (11f, 9 m; FU ø31.6 months). The SRR was performed with three to five transosseus mattress sutures. DRR consisted of two medial placed transosseus sutures and four laterally placed single tendon-to-tendon sutures. The postoperative subscapularis integrity was evaluated by ultrasound examination, the clinical outcome was assessed with the Constant-Murley Score (CS) and the American Shoulder and Elbow Surgeons Score (ASES).

RESULTS

The subscapularis tendon was intact in 14 patients (70%) after SRR, whereas 18 patients (90%) treated with the DRR demonstrated a sonographically intact postoperative subscapularis tendon. The CS was 61.4 points in the SRR cohort and 67.3 points in the DRR cohort (p = 0.314). No significant differences were found in both cohorts preoperative (øSRR: 21.3 points; øDRR: 16.2 points, p = 0.720) and postoperative absolute ASES Scores (øSRR: 70.2 points; øDRR: 73.0 points, p = 0.792). However, the DRR cohort showed a statistical tendency to a higher postoperative ASES increase than the SRR cohort (øSRR-ASES increase: 48.9 points; øDRR-ASES increase: 56.8 points, p = 0.067).

CONCLUSION

The results of this study show that application of the DRR technique can significantly reduce the total rate of postoperative subscapularis tears what effects a clinical tendency towards higher ASES improvements and a better range of motion compared to the SRR technique.

Arthroscopic iliac crest bone grafting in recurrent anterior shoulder instability: minimum 5-year clinical and radiologic follow-up

PURPOSE

To investigate the clinical and radiologic mid- to long-term results of arthroscopic iliac crest bone-grafting for anatomic glenoid reconstruction in patients with recurrent anterior shoulder instability.

METHODS

Seventeen patients were evaluated after a minimum follow-up of 5 years. Clinical [range of motion, subscapularis tests, apprehension sign, Subjective Shoulder Value (SSV), Constant Score (CS), Rowe Score (RS), Walch Duplay Score (WD), Western Ontario Shoulder Instability Index (WOSI)], and radiologic [X-ray (true a.p., Bernageau and axillary views) and computed tomography (CT)] outcome parameters were assessed.

RESULTS

Fourteen patients [mean age 31.1 (range 18-50) years] were available after a follow-up period of 78.7 (range 60-110) months. The SSV averaged 87 (range 65-100) %, CS 94 (range 83-100) points, RS 89 (range 30-100) points, WD 87 (range 25-100) points, and WOSI 70 (range 47-87) %. The apprehension sign was positive in two patients (14%). One patient required an arthroscopic capsular plication due to a persisting feeling of instability, while the second patient experienced recurrent dislocations after a trauma, but refused revision surgery. CT imaging showed a significant increase of the glenoid index from preoperative 0.8 ± 0.04 (range 0.7-0.8) to 1.0 ± 0.11 (range 0.8-1.2) at the final follow-up (p < 0.01).

CONCLUSION

Arthroscopic reconstruction of anteroinferior glenoid defects using an autologous iliac crest bone-grafting technique yields satisfying clinical and radiologic results after a mid- to long-term follow-up period. Postoperative re-dislocation was experienced in one (7.1%) of the patients due to a trauma and an anatomic reconstruction of the pear-shaped glenoid configuration was observed.

LEVEL OF EVIDENCE

IV.

Subscapularis integrity, function and EMG/nerve conduction study findings following reverse total shoulder arthroplasty

Background

During reverse total shoulder arthroplasty, the functionality of the subscapularis remains unknown. The purpose of this study was to determine the integrity and function of the repaired subscapularis after reverse total shoulder arthroplasty using ultrasound, electromyography (EMG), and nerve conduction studies (NCS) to assess postoperative tendon healing, muscle, and nerve function.

Materials and methods

Patients who underwent reverse total shoulder arthroplasty and repair with minimum 6-month follow-up were included in the study. Patient-reported outcome, physical examination, ultrasound examination of the subscapularis tendon, subscapularis EMG, and lower subscapular NCS were performed. In addition, contralateral subscapularis ultrasound, EMG, and lower subscapular nerve nerve NCS were performed to establish normative values (abnormal defined at >20% increased latency or >50% decreased amplitude). Phi coefficients of association and point biserial coefficients were used to correlate the ultrasound examination, EMG, and NCS results with the functional outcomes.

Results

A total of 20 patients were included. Four patients had abnormal but intact subscapularis tendons on ultrasound. Nine patients had abnormal lower subscapular NCS compared with the contralateral shoulder. All patients had normal subscapularis EMGs. No significant correlation was found between the ultrasound and NCS results. No significant correlations were found between the ultrasound or the NCS results and any of the independent outcome variables.

Conclusion

This study demonstrates that the subscapularis remains neurologically functional after reverse total shoulder arthroplasty, based on EMG and NCS findings. Although side-to-side differences in lower subscapular NCS were identified in 45% of the postoperative shoulders, these abnormalities did not correlate with functional outcomes.

Shoulder Hemiarthroplasty After Previous Pectoralis Major Transfer for Irreparable Subscapularis Tear: A Case Report

CASE

A 30-year-old woman with an irreparable subscapularis tear presented with persistent painful anterior instability despite several open and arthroscopic stabilization procedures. A pectoralis major tendon transfer (PMTT) was performed. The patient subsequently developed progressive glenohumeral arthritis over the next 10 years, ultimately necessitating shoulder arthroplasty.

CONCLUSIONS

PMTT provides valuable anterior soft-tissue reconstruction stabilization for subscapularis insufficiency in a multioperated shoulder. Ten years later, the transfer was found to be intact and managed like a native subscapularis during anatomic shoulder replacement, thus avoiding a reverse arthroplasty in a young patient.

Postoperative MR Imaging in Shoulder Instability and Intra-articular Damage

MR imaging of the postoperative shoulder after instability surgery is challenging. The radiologist must be familiar with surgical procedures, altered anatomy, and expected postoperative findings for correct interpretation of normal findings versus a true pathology. Artifacts from metallic hardware or abrasions further complicate MR image interpretation, but are reduced with metal artifact reduction techniques. This article focuses on capsulolabral surgery, bone block transfers, and humeral bone loss procedures in patients with shoulder instability and their postoperative imaging evaluation. Surgical procedures and common complications are explained, and normal and pathologic postoperative imaging findings are presented.

Posterior Approach Total Shoulder Arthroplasty: A Retrospective Analysis of Short-term Results

Subscapularis dysfunction and failure are the leading causes of complications of total shoulder arthroplasty (TSA). An approach to shoulder arthroplasty has been described that may improve exposure to the retroverted glenoid and spare the rotator cuff. This article details the 6-month clinical outcomes of the first 26 patients who underwent TSA using a posterior approach. Thirty-one patients who underwent TSA using a posterior approach between September 2016 and October 2017 were identified retrospectively. Patients were assessed for American Shoulder and Elbow Surgeons (ASES) scores, Simple Shoulder Test (SST) scores, range of motion, complications, radiographic outcomes, and patient satisfaction. Statistical models were used to compare the means for each outcome variable over time. Of the initial 31 patients, 26 patients were available for follow-up at a minimum of 6 months; the remaining 5 patients did not return for follow-up at 6 months. Significant improvement in each outcome variable from baseline was noted by 6 weeks postoperatively. Further improvement was observed at 3 months for SST and external rotation, and at 6 months for ASES function and forward flexion. All outcome variables demonstrated some improvement from one time point to the next. Posterior TSA is a safe and efficacious procedure at 6 months. Compared with traditional TSA, posterior cuff-sparing approaches may improve posterior joint access, posterior soft tissue balancing, and long-term rotator cuff issues. [Orthopedics. 2020; 43(1):e15-e20.].

Subscapularis structural integrity and function after arthroscopic Latarjet procedure at a minimum 2-year follow-up

BACKGROUND

Subscapularis function after arthroscopic Bankart repair has been widely studied. However, data regarding subscapularis performance after arthroscopic Latarjet procedures are lacking. This study aimed to evaluate subscapularis clinical and radiologic performance after arthroscopic Latarjet procedures.

METHODS

We included 40 patients who underwent arthroscopic Latarjet procedure with a minimum 2-year follow-up. Clinical evaluation included Western Ontario Shoulder Instability Index and Rowe scores, specific subscapularis isokinetic study, and lift-off tests. Contralateral measurements were used for comparison. Computed tomographic evaluation included graft consolidation, muscle dimensions, and degree of fatty atrophy, calculated as the mean muscle attenuation (MMA).

RESULTS

There was a decrease of 8.3% of maximum internal rotation peak torque in the operated arm (P = .02). However, there was no significant difference in the agonist-antagonist ratio: 76.9% in the operated arm and 76% in the contralateral (P = .82). Lift-off strength test demonstrated a decrease in the first year but not at final follow-up (P = .38). There was a significant decrease in lift-off distance of 23% compared to the contralateral side (P < .001). Subscapularis MMA was diminished when compared to the infraspinatus/teres minor (P < .001) at the expense of its upper part (P = .03). Hyperlaxity and number of dislocation episodes were correlated to a lower MMA (P = .046 and P = .005).

CONCLUSION

Arthroscopic Latarjet procedures provide satisfactory clinical results. There seems to be a diminished subscapularis MMA depending on its superior half. Hyperlaxity and number of previous dislocations were correlated to a lower MMA. Although there was a decrease in the maximum internal rotation peak torque, we did not find any difference in the agonist-antagonist ratio or in the final lift-off strength between sides.

Biomechanical comparison of subscapularis peel and lesser tuberosity osteotomy for double-row subscapularis repair technique in a cadaveric arthroplasty model

INTRODUCTION

Management of the subscapularis during shoulder arthroplasty is controversial. The purpose of this study was to compare the biomechanical performance of subscapularis peel (SP) and lesser tuberosity osteotomy (LTO) in a cadaveric model.

METHODS

The subscapularis and proximal humerus were dissected from all soft tissues in 21 fresh-frozen human cadaveric shoulders and randomized to undergo SP, LTO, or standard subscapularis tenotomy (ST, control). For SP and LTO, six #5 sutures were passed through eyelets in the implant (on lateral border and through drill holes in bicipital groove [2] and under trunion [4]). Double-row repair was performed using two lateral row transosseous sutures and four medial row sutures through the tendon (SP) or osseotendinous junction (LTO). Biomechanical properties and mode of failure were tested.

RESULTS

There were no significant differences in elongation amplitude, cyclic elongation, or maximum load to failure between the three groups (P > 0.05). Mean stiffness was significantly higher in LTO (P = 0.009 vs. SP and ST). In the ST group, 7/7 specimens failed at the tendon-suture interface. For SP, 4/7 failed at the tendon-suture interface, one at the suture-bone interface, one fractured around the implant stem, and one at the knots. For LTO, 3/7 failed at the tendon-suture interface, two at the suture-bone interface and two fractured around the implant stem.

CONCLUSIONS

In this cadaveric model, subscapularis repair via ST, SP, and LTO techniques was biomechanically equivalent. Additional studies are needed to confirm these findings and determine the influence of biologic healing on healing rates and clinical outcomes.

LEVEL OF EVIDENCE

N/a, biomechanical laboratory study.

All-arthroscopic, guided Eden-Hybbinette procedure using suture-button fixation for revision of failed Latarjet

PURPOSE

To report the results of a guided arthroscopic Eden-Hybbinette procedure, using suture button for iliac crest bone graft fixation, in a series of patients with a prior failed Latarjet and persistent glenoid bone loss.

METHODS

Seven consecutive patients (5 males, 2 females, mean age: 30.7 years [range, 17-47 years]) with recurrent anterior dislocations and glenoid deficiency greater than 20% underwent the all-arthroscopic revision procedure. The iliac crest bone graft and suture-button device (Bone-Link) were shuttled through the rotator interval. Specific drill guides were used and a suture tensioning device allowed bone graft compression. Previous broken screw shafts (3 patients) were left in situ. Graft placement and healing was assessed postoperatively with computed tomography imaging.

RESULTS

No neurologic injury or hardware problems occurred, and no patient required further surgery. On computed tomography scan, optimal positioning (flush and under the equator) and healing of the bone graft was observed in all patients. At a mean follow-up of 21 months (range, 12-39 months), all but one patient were satisfied and had a stable shoulder; 5 returned to sports. The Constant score increased from 32 to 81 points, and the subjective shoulder value from 31% to 87% (P < .001). The Walch-Duplay and Rowe scores averaged 85.7 (range, 65-100) points and 86.4 (range, 70-100) points, respectively.

CONCLUSION

Recurrence of anterior shoulder instability after a failed Latarjet procedure can be successfully treated by an all-arthroscopic Eden-Hybbinette procedure. Suture-button fixation is reliable and permits optimal positioning and predictable healing of the new bone graft; in addition, it is an appropriate fixation option in the setting of retained broken hardware.

Characterization of an anatomic safe zone surrounding the lower subscapular nerve during an open deltopectoral approach

BACKGROUND

Due to anatomic variance in subscapular nerve innervation patterns, it is theorized that the dysfunction of the subscapularis could be the result of iatrogenic denervation during mobilization of the subscapularis while exposing the anterior glenohumeral joint in anterior surgical approaches. The purpose of this study was to describe innervation patterns of the subscapularis and to characterize a safe zone when conducting an anterior surgical approach.

METHODS

The study used 6 human cadaveric shoulder specimens (12 shoulders total). A deltopectoral approach was used to expose the axillary nerve back to the posterior cord of the brachial plexus and reveal the origins of the upper and lower subscapularis nerves. An anatomic safe zone was characterized by measuring distances from both the upper and lower subscapularis nerve insertions with respect to that of the lateral border of the conjoint tendon, the bicipital groove, superior border of the subscapularis, and the axillary nerve (for the lower subscapular nerve only) with the arm in 30° abduction.

RESULTS

The anatomic safe zone of the subscapular nerves medial to the conjoint tendon is less than 32 mm. In relation to the axillary nerve, the safe zone is less than 10 mm inferiorly and 15 mm medially.

CONCLUSIONS

This described safe zone with respect to the lateral border of the conjoint tendon and axillary nerve is aimed to provide guidance to reduce iatrogenic injury of the subscapular nerves during anterior shoulder exposure. Extra care should be undertaken while dissecting past this safe zone to prevent iatrogenic subscapular nerve injury.

Subscapularis Management in Total Shoulder Arthroplasty: Current Evidence Comparing Peel, Osteotomy, and Tenotomy

The optimal approach to management of the subscapularis in total shoulder arthroplasty (TSA) is controversial. Options include the subscapularis tenotomy, lesser tuberosity osteotomy (LTO), and peel. This review provides a summary of subscapularis anatomy and function, outcomes associated with subscapularis management options in TSA, and postoperative subscapularis deficiency. Based on the available literature, LTO appears to result in improved function and subscapularis integrity relative to tenotomy, while peel and LTO have generally led to equivalent outcomes. The highest level of evidence to date is derived from a randomized controlled trial that demonstrated that outcomes following peel and LTO were not significantly different. There is currently a paucity of high-quality evidence as most studies have consisted of small retrospective series with varying outcome measures. Furthermore, the optimal approach to establishing the diagnosis of subscapularis deficiency following TSA is unclear.

Multidirectional Instability of the Shoulder: Treatment Options and Considerations

Multidirectional instability (MDI) is a debilitating condition that involves chronic subluxation or dislocation of the shoulder in >1 direction. Numerous proposed mechanisms of MDI exist, which occurs in the setting of redundant capsular tissue. Symptoms can range from recurrent dislocations or subluxations to vague aching pain that disrupts activities of daily living. Magnetic resonance imaging is often performed during evaluation of this condition, although magnetic resonance arthrography may provide more detailed images of the patulous capsule. In the absence of a well-defined traumatic cause, such as a labral tear, initial treatment for MDI is a structured rehabilitation program with exercises aimed at strengthening the rotator cuff and periscapular muscles to improve scapular kinematics. Patients with recalcitrant symptoms may benefit from surgical stabilization, including open capsular shift or arthroscopic capsular plication, aimed at decreasing capsular volume and improving stability.

Subscapularis Insufficiency: What’s All the Fuss About?

There has been increase attention to the surgical treatment of the subscapularis (SSC) tendon with risk of postoperative dysfunction and early failures following shoulder arthroplasty. Studies investigating the clinical results after shoulder arthroplasty indicate that SSC tendon detachment or incision techniques and rehabilitation concepts may impair SSC recovery and consequently the postoperative function. In response to these results, technical modifications have been proposed and evaluated anatomically, biomechanically, and clinically. The aim of this article is to give an overview of current SSC take-down approaches, subsequent repair techniques, and postoperative rehabilitation protocols as well as to present the diagnostic algorithm and clinical impacts of the increasingly acknowledged condition of SSC insufficiency following shoulder arthroplasty procedures.

Back to Sports After Arthroscopic Revision Bankart Repair

BACKGROUND

Recurrent instability following primary arthroscopic stabilization of the shoulder is a common complication. Young, athletic patients are at the greatest risk of recurring instability. To date, the literature contains insufficient description regarding whether return to sports is possible after revision arthroscopic Bankart repair.

HYPOTHESIS

Patients presenting with recurrent instability after primary arthroscopic stabilization should expect limitations in terms of their ability to partake in sporting activities after revision surgery.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Twenty athletes who underwent arthroscopic revision stabilization of the shoulder after failed primary arthroscopic Bankart repair were included in the study after completing inclusion and exclusion criteria surveys. Athletic Shoulder Outcome Scoring System (ASOSS), Shoulder Sport Activity Score (SSAS), and the Subjective Patient Outcome for Return to Sports (SPORTS) scores were determined to assess the participants' ability to partake in sporting activities. Furthermore, sport type and sport level were classified and recorded. To assess function and stability, Rowe, American Shoulder and Elbow Surgeons, Constant-Murley, and Walch-Duplay scores were measured and recorded.

RESULTS

Follow-up consultations were carried out after a mean of 28.7 months. The mean age at follow-up examination was 27.75 years. At the time of follow-up, 70% of the patients were able to return to their original sporting activities at the same level. However, 90% of patients described a limitation in their shoulder when participating in their sports. At 28.7 months after surgery, the mean ASOSS score was 76.8; the SSAS score decreased from 7.85 before first-time dislocation to 5.35 at follow-up (P < .005). The SPORTS score was 5.2 out of 10 at the follow-up consultation. Function- and instability-specific scores showed good to excellent results. The mean external rotational deficit for high external rotation was 9.25°, and for low external rotation it was 12°.

CONCLUSION

Patients can return to their original type and level of sport after arthroscopic revision Bankart repair, but they must expect persistent deficits and limitations to the shoulder when put under the strains of sporting activity. Patients with shoulder injuries who partake in sports that put greater demand on the shoulder show the smallest probabilities of returning to sporting activity.

Rotator cuff muscular integrity after arthroscopic revision of a Bankart repair

INTRODUCTION

Recurrent shoulder instability after arthroscopic Bankart repair is still a common complication. For primary Bankart repair studies have shown that the rotator cuff can recover completely. The ability of muscles to regenerate after arthroscopic revision Bankart repair (ARBR) has not been studied. Does the ARBR using a three-portal method allows complete muscle integrity compared with an uninjured imaging control group (ICG)?

MATERIALS AND METHODS

Twenty-two (1 female, 21 males) physically active patients (mean age at follow-up 28.5 ± 7.1 years; mean follow-up 27.5 months ± 8.5) were assessed. ARBR with a three-portal method was carried out in all patients according to previous primary arthroscopic stabilization of the shoulder (revision Bankart group). Muscle atrophy of the subscapularis muscle (SSC), supraspinatus muscle (SSP) and infraspinatus muscle (ISP) was assessed by making lateral and vertical measurements by magnetic resonance imaging (MRI). Fatty infiltration was detected by standardized assessment from variations in intensity. Detailed clinical examination of the rotator cuff was carried out. MRI assessment was compared with that of a control group of 22 healthy volunteers of same age and activity level (ICG).

RESULTS

For the SSC, no muscle impairment was noted compared with the ICG [superior atrophy index (sAI_SSC), p = 0.439; inferior atrophy index (iAI_SSC), p = 0.555; superior fatty infiltration index (sFDI_SSC), p = 0.294; inferior fatty infiltration index (iFDI_SSC), p = 0.62]. In investigation of the SSP and ISP, fatty infiltration was not shown (FDI_SSP, p = 0.454; sFDI_ISP, p = 0.504), though persistent muscle atrophy was found even > 2 years after surgery compared with the ICG (AI_SSP, p = 0.0025; sAI_ISP, p = 0.0009; iAI_ISP, p = 0.0004).

CONCLUSION

ARBR using a three-portal method allowed good muscular integrity compared with the ICG, but with persistent slight muscular atrophy of the SSP and ISP.

Subscapularis-On Approach in Reverse Shoulder Arthroplasty

Using a subscapularis- and deltoid-preserving anterior approach is an option for patients undergoing reverse shoulder arthroplasty. Outcomes are better at short term than compared with the standard deltopectoral approach. Maintaining the integrity of the subscapularis tendon and preserving the deltoid muscle minimizes the need for postoperative immobilization and rehabilitation, allowing the patient to achieve active shoulder range of motion more rapidly, without increasing the incidence of shoulder dislocation. Overall length of hospital stay and duration of postoperative physical therapy are minimized, leading to significant economic gain. Future studies with longer follow-up are required to document the potential long-term benefits of this surgical technique.

Level of Evidence of the study: Review, Level IV

The Open Bankart Repair for Traumatic Anterior Shoulder Instability in Teenage Athletes

BACKGROUND

Traumatic anterior shoulder instability from recurrent dislocations or subluxations is a debilitating problem for the teenage athlete. The risk of recurrent instability is high in this adolescent population. We performed a retrospective case series analysis of adolescent athletes with recurrent instability treated with open Bankart repair and evaluated functional outcomes as well as redislocation rates.

METHODS

The retrospective study included 21 teenage patients with Bankart lesions and recurrent anterior shoulder instability. There were 19 males (90%) and 2 females (10%) with an average age of 16 years (range, 14 to 18 y). Patients were evaluated based on Rowe and UCLA shoulder scores, return to previous level of sport, external rotation, and recurrence.

RESULTS

The average number of anchors used to repair the Bankart lesion was 3 (range, 2 to 5). One patient was lost to follow-up at 6 months after surgery. The remaining 20 patients all had at least 2-year follow-up. The recurrent instability rate was zero. In total, 100% of patients had an excellent result based on an average Rowe score of 96.5 points of 100 points (a score of 90 to 100 is an excellent result). In total, 100% of patients had good/excellent result based on an average UCLA shoulder score of 34 of 35 (a score >27 is a good/excellent result). At final follow-up, 7 patients (34%) had lost an average of 11 degrees of external rotation (range, 5 to 20 degrees) on the injured shoulder with the arm at the side compared with the noninjured shoulder.

CONCLUSIONS

Contact teenage athletes with recurrent anterior shoulder instability can be treated with open Bankart repair with a low recurrence, excellent functional shoulder outcomes, and return to sport. A small amount of external rotation may be lost with this technique. Care must be taken when considering this method with throwing athletes (ie, quarterback or pitcher). The open Bankart should remain a viable alternative for the adolescent population with recurrent anterior instability.

LEVEL OF EVIDENCE

Level IV.

Diagnostic performance of clinical tests for subscapularis tendon tears

PURPOSE

Tears of the subscapularis (SSC) tendon constitute a diagnostic challenge. The purpose of the present study was to evaluate the diagnostic capabilities of five clinical SSC tests.

METHODS

Five established clinical tests were evaluated in 106 consecutive patients prior to shoulder arthroscopy. The tests included the Lift Off Test, Internal Rotation Lag Sign, Belly Press Test, Belly Off Sign, and Bear Hug Test. The integrity of the SSC tendon at surgery was used as the gold standard. Lesions to the SSC were graded according to Fox and Romeo.

RESULTS

There were 32 SSC lesions accounting for an incidence of 30.2%. The sensitivity for all tests was 0.66, while the specificity was 0.82. For all tests, positive tests results were found to be dependent on subscapularis integrity (p < 0.001, respectively). The sensitivity for any type of SSC lesion for the Lift Off Test, Internal Rotation Lag Sign, Belly Press Test, Belly Off Sign, and Bear Hug Test was 0.35, 0.41, 0.34, 0.31, and 0.52, respectively. Specificity was found to be 0.98, 0.91, 0.96, 0.97, and 0.85, respectively. If only grade 2-4 tears were analysed, sensitivity was 0.32, 0.42, 0.37, 0.37, and 0.72 and specificity 0.94, 0.86, 0.92, 0.94, and 0.84. A positive correlation was found between the number of positive tests and the severity of the SSC lesions.

CONCLUSION

In the present study, the Bear Hug Test was found to have the highest sensitivity of all tests studied, especially for tears of the upper tendon border. It appears advisable to perform more than one clinical subscapularis test to further improve sensitivity. Nevertheless, SSC tears may still escape clinical recognition. Therefore, a high index of suspicion has to be maintained in order not to miss SSC tears.

LEVEL OF EVIDENCE

Diagnostic study, Level I.

Subscapularis Peel in Anatomic Total Shoulder Arthroplasty

Background

Anatomic total shoulder arthroplasty is a viable treatment option for patients with glenohumeral arthritis and an intact rotator cuff with successful outcomes. However, one complication is rupture of the subscapularis tendon postoperatively. Controversy exists regarding the optimal technique of subscapularis tendon management. The purpose of the present article is to review subscapularis peel repair method.

Methods

The current literature on anatomic total shoulder arthroplasty and subscapularis peel was reviewed to determine the viability of the repair technique.

Results

Both biomechanical and clinical studies have demonstrated advantages and disadvantages of the subscapularis peel technique, most often by way of direct comparison with lesser tuberosity osteotomy, without consensus as to a superior repair method.

Discussion

The subscapularis peel repair in anatomic total shoulder arthroplasty when performed correctly may yield successful biomechanical and clinical outcomes for patients.

Level of the Subscapularis Split During Arthroscopic Latarjet

PURPOSE

To determine the location of the subscapularis split during arthroscopic Latarjet created by an inside-out technique passing a switching stick from the posterior portal across the glenohumeral joint.

METHODS

An inside-out technique was used to arthroscopically create a subscapularis split in 20 fresh-frozen human cadaveric shoulders. The distance between the exit point of the switching stick and the upper border of the subscapularis and the anterior circumflex vessels was measured arthroscopically and after open dissection.

RESULTS

Twelve splits were in the upper third of the subscapularis, 3 were at the junction of the upper third and the middle third, and 5 were in the middle third. None were at the junction between the middle and lower third as desired.

CONCLUSIONS

Using the inside-out method during arthroscopic Latarjet may produce a high subscapularis split if it is performed from with a switching stick that is inserted through the posterior approach, and passed across the glenohumeral joint at the level of the inferior glenoid.

CLINICAL RELEVANCE

This study analyzed the relative risk of high subscapularis split during the arthroscopic Latarjet procedure.

Controversies in the Surgical Management of Shoulder Instability: Open vs Arthroscopic Procedures

BACKGROUND

Traumatic anterior instability of the shoulder is a common condition associated with a high recurrence rate in young adults. Operative treatment reduces the risk of recurrence. Several studies have compared arthroscopic and open shoulder instability repair. The purpose of this paper is to perform a review of the literature where both techniques are compared in the repair of the anterior shoulder instability without bone loss.

METHODS

Prior to arthroscopy, recurrent dislocations were managed by open repair. There have been many studies documenting low recurrence rates after open Bankart stabilization. Initially, arthroscopic fixation reported high failure rates.

RESULTS

In the last 20 years, the development of arthroscopic stabilization for recurrent anterior instability has improved failure rates. In comparison with open techniques, arthroscopic procedures have the advantages of decreased morbidity rate, early functional rehabilitation and improved range of motion.

CONCLUSION

The available evidence does not show a statistically significant difference in outcome measures between arthroscopic and open repair for the treatment of recurrent anterior shoulder instability. Given the similar results between the 2 groups, differences in length of hospital stay and cost to the patient and society point to arthroscopic repair as the more judicious treatment approach.

Nerve supply of the subscapularis during anterior shoulder surgery: definition of a potential risk area

PURPOSE

The purpose of the study was to evaluate the position of the subscapular nerves relative to surgical landmarks during exposure and to analyze the pattern of innervation of the subscapularis to avoid injury during anterior shoulder surgery.

METHODS

20 embalmed human cadaveric shoulder specimens were used in the study. The muscular insertions of the subscapular nerves were marked and their closest branches to the musculotendinous junction and the coracoid process were measured in horizontal and vertical distances. In addition, the innervation pattern of each specimen was documented.

RESULTS

14/20 specimens showed an innervation of the subscapularis with an upper, middle and lower subscapular nerve branch. Even though the nerve branches were in average more than 2 cm medial to the musculotendinous junction, minimal distances of 1.1-1.3 cm were found. The mean vertical distance as measured from the medial base of the coracoid to the nerve innervation point into the muscle was 0.7 cm for the upper nerve branch, 2.2 cm for the middle nerve branch and 4.4 cm for the lower nerve branch.

CONCLUSIONS

The subscapularis has a variable nerve supply, which increases the risk of muscle denervation during open shoulder surgery. Dissection or release should be avoided at the anterior aspect of the subscapularis muscle more than 1 cm medial to the musculotendinous junction. In approaches with a horizontal incision of the subscapularis, splitting should be performed at a vertical distance of 3.2-3.6 cm to the coracoid base to avoid iatrogenic subscapular nerve injuries.

Management of an engaging Hill-Sachs lesion: arthroscopic remplissage with Bankart repair versus Latarjet procedure

PURPOSE

This study compared the clinical outcomes of arthroscopic remplissage with Bankart repair and Latarjet operation in patients with a large engaging Hill-Sachs lesion.

METHODS

Thirty-seven shoulders subjected to arthroscopic remplissage with a Bankart repair (group A) and 35 shoulders subjected to a Latarjet operation (group B), for a large engaging Hill-Sachs lesion without significant glenoid bone loss, were retrospectively evaluated. Each group was followed up for a mean more than 2-year period.

RESULTS

At the last follow-up, postoperative pain, shoulder mobility, muscle strength, Rowe score, and UCLA score revealed no significant difference between the two groups. The postoperative mean deficit in external rotation at the side (ERs) was 8° ± 23° in group A (P = 0.044). In group B, the mean deficits in ERs, external rotation at 90° of abduction, and internal rotation to the posterior were 10° ± 20°, 7° ± 16°, and 1.9° ± 4°, respectively (P = 0.004, 0.022, and 0.009, respectively). The recurrence rate was 5.4 % (two shoulders) in group A and 5.7 % (two shoulders) in group B (n.s.). The overall complication rate was significantly higher in group B (14.3 %) than in group A (0 %) (P = 0.017).

CONCLUSIONS

For recurrent anterior shoulder instability with a large engaging Hill-Sachs lesion, both arthroscopic remplissage with Bankart repair and the Latarjet procedure were safe and reliable techniques with a low recurrence rate. However, the Latarjet group had a significantly higher postoperative complication rate than the remplissage group.

LEVEL OF EVIDENCE

Case-control study, Level III.

Patterns of strain and the determination of the safe arc of motion after subscapularis repair--A biomechanical study

This study characterizes the strain patterns and safe arcs for passive range of motion (ROM) in the superior and inferior subscapularis tendon in seven cadaveric shoulders, mounted for controlled ROM, after deltopectoral approach to the glenohumeral joint, including tenotomy of the subscapularis tendon 1 cm medial to its insertion on the lesser tuberosity. The tenotomy was repaired with end-to-end suture in neutral rotation. Strain patterns were measured during passive ROM in external rotation (ER), ER with 30° abduction (ER+30), abduction, and forward flexion in the scapular plane (SP) before and after surgery. Percentages were calculated from 35 trials corresponding to five trials of each motion across seven specimens. With ER of 0-30°, 89% of trials of superior subscapularis tendon and 100% of trials of inferior subscapularis tendon achieved strains >3%, with very similar patterns noted in ER+30. In abduction of 0-90°, 5.8% of trials of superior and 85.3% of trials of inferior tendon achieved >3% strain. With passive ROM in SP, 26.5% of trials reached 3% strain in superior tendon compared to 100% in inferior tendon. Strain patterns in abduction and SP differed significantly (p < 0.001). Selective tenotomy and repair of the superior subscapularis tendon with open reparative or reconstructive shoulder procedures, when feasible, may be favorable for protected early passive ROM and rehabilitation postoperatively.

RESULTS FROM LATARJET SURGERY FOR TREATING TRAUMATIC ANTERIOR SHOULDER INSTABILITY ASSOCIATED WITH BONE EROSION IN THE GLENOID CAVITY, AFTER MINIMUM FOLLOW-UP OF ONE YEAR

Objective: Evaluate the results from the Latarjet procedure in patients with anterior recurrent dislocation of the shoulder who present bone loss of the glenoid cavity greater than 25%. Methods: Twenty six male patients underwent the Latarjet procedure, The bone loss was evaluated by means of radiography using the Bernageau view and by means of CAT scan. The patients were evaluated with regard to range of motion, using the Rowe and UCLA scales, before and after the operation, and by radiographs to assess the presence of arthrosis, position and consolidation of the graft and positioning of the screws. Statistical analysis was used to assess whether there was any relationship between the number of episodes of dislocation and the presence of arthrosis, , and any relationship between arthrosis and limitations on lateral rotation. Differences in range of motion between the operated and unaffected sides and in the UCLA and Rowe scale. Results: The means for elevation and lateral rotation were statistically poorer on the operated side. The UCLA and Rowe scale showed that there was a statistically significant improvement in the clinical-functional results (P < 0.001 for both). There was a relationship between the number of episodes of dislocation and the presence of arthrosis, We also did not observe any correlation between limitations on lateral rotation and arthrosis. Conclusion: The Latarjet procedure is an efficient method for cases of severe erosion of the glenoid margin.

Arthroscopic partial shoulder resurfacing

PURPOSE

The purpose of this study was to report patients' clinical and subjective outcomes 2 years after arthroscopic-assisted partial resurfacing of the humeral head.

METHODS

In this prospective case series, 11 patients (4 females, 7 males; median age, 59 years; range 47-72) underwent arthroscopic-assisted partial shoulder resurfacing between April 2010 and March 2011. Clinical conditions and subjective assessments were evaluated before surgery and at 6 weeks, 3 and 6 months, and then annually after surgery using the Constant score (CS), active range of motion (ROM), the visual analogue scale (VAS) for pain, the American Shoulder and Elbow Surgeons scale (ASES), and the subjective shoulder value (SSV). Radiological outcomes and major complications were monitored.

RESULTS

The mean CS improved significantly from 54.6 ± 13.6 preoperatively to 72.9 ± 17.2 points 6 weeks postoperatively (P = 0.009). At the 2-year follow-up, the mean CS had further increased to 86.5 ± 14.3 points (P < 0.001). Trends towards increasing ROMs were detected. VAS, ASES, and SSV significantly improved from baseline to the first follow-up and maintained improvement after 2 years. One patient required revision surgery owing to a technical failure and two patients because of rapidly progressive osteoarthritis. Ten of 11 patients (91 %) claimed that they would undergo arthroscopic partial shoulder resurfacing again.

CONCLUSION

Arthroscopic-assisted partial humeral head resurfacing, which has the advantages of bone stock preservation and the maintenance of an intact subscapularis tendon, allowed immediate postoperative mobilization and provided significant improvements in subjective outcomes, especially for pain relief in active patients without severe glenoid cartilage wear.

LEVEL OF EVIDENCE

Therapeutic case series, Level IV.

The subscapularis-sparing approach in humeral head replacement

BACKGROUND

This report represents a prospective case series evaluating an open deltopectoral approach, both radiologically and clinically, without tenotomy or complete takedown of the subscapularis tendon insertion. We hypothesized that this novel technical approach would allow preservation of the upper tendon border, thus decreasing subscapularis repair failures and fatty infiltration while simultaneously allowing accelerated rehabilitation.

METHODS

Fifty patients underwent humeral head replacement surgery through a subscapularis-sparing approach. In this approach, we take down only the inferior 30% to 50% of the subscapularis tendon, leaving the critical superior aspect of the tendon attached to the lesser tuberosity. Forty-three patients were included in the postoperative results (7 were lost to follow-up). Nineteen patients had a postoperative magnetic resonance imaging study, and 24 patients had ultrasound evaluation. Physical examination included belly-press and lift-off tests; follow-up included visual analog scale, American Shoulder and Elbow Surgeons, Constant, modified UCLA, Rowe, and Short Form 12 scores.

RESULTS

All patients had a minimum 2-year follow-up. All patients had subscapularis strength equal to the opposite side as measured by lift-off, belly-press, and bear hug tests. Average postoperative scores all showed statistically significant improvement except for general health. All had an intact subscapularis tendon attachment as evaluated by either magnetic resonance imaging or ultrasound imaging. None had atrophy in the muscle belly.

CONCLUSIONS

The subscapularis-sparing, minimally invasive approach to the glenohumeral joint provides adequate exposure to allow humeral head replacement. When the upper border of the subscapularis insertion is left intact, there is a decreased risk of postoperative failure (rupture or atrophy) of the subscapularis tendon.

Internal rotation resistance test at abduction and external rotation: a new clinical test for diagnosing subscapularis lesions

PURPOSE

A new clinical test for evaluating subscapularis (SSC) integrity was described, and its diagnostic value was compared with the present SSC tests (the lift-off, belly-press, IRLS and bear-hug tests). The new test is called internal rotation resistance test at abduction and external rotation (IRRT). The test is performed at maximal 90° of abduction and maximal external rotation.

METHODS

Two hundred and thirty-five consecutive patients suffering from rotator cuff injury were evaluated preoperatively. Six tests were performed to assess the function of the SSC: the lift-off, belly-press, IRLS, the bear-hug, IRRT at 0° abduction and 0° external rotation (IRRT0°) and IRRT at maximal 90° abduction and maximal external rotation (IRRTM). Arthroscopic findings were the reference for diagnosing of SSC lesions.

RESULTS

The IRRTM test showed the greatest sensitivity (76.5 %), and IRLS (31.6 %) test had the lowest sensitivity. The IRRTM had the highest accuracy (79.0 %), and lift-off had the lowest accuracy (65.3 %). Positive IRRTM, bear-hug, belly-press, IRRT0° tests indicate that about one-third of the SSC is torn, and a positive lift-off and IRLS tests predict a severe tear at least two-thirds of the SSC.

CONCLUSIONS

The IRRTM represents a sensitive diagnostic test for SSC lesions and improves the chance of finding the upper part of the SSC tears. When the IRRTM is positive, the surgeon should pay particular attention to detecting the SSC tendon during arthroscopy.

LEVEL OF EVIDENCE

Diagnostic study, Level I.

Multidirectional instability of the shoulder: biomechanics, clinical presentation, and treatment strategies

Multidirectional instability (MDI) of the shoulder is a condition where the dislocation occurs in more than one direction with minimal or no causative trauma. Its pathoanatomy is complex and characterized by a redundant capsule, resulting in increased glenohumeral joint volume. The fact that several further factors may contribute to symptom onset complicates the diagnosis and hampers the identification of a therapeutic approach suitable for all cases. There is general agreement that the initial treatment should be conservative and that surgery should be reserved for patients who have not responded to an ad hoc rehabilitation program. We review the biomechanics, clinical presentation, and treatment strategies of shoulder MDI.

Deltopectoral approach for shoulder arthroplasty: anatomic basis

PURPOSE

The deltopectoral approach is a common surgical procedure for shoulder arthroplasty. Many surgeons are familiar with this procedure, but certain steps are still controversial. This is the case for the management of subscapularis, where surgeons must choose between tenotomy and the lesser tuberosity osteotomy.

METHODS

This article is conceived as a toolkit for the inexperienced surgeons, describing our tips and tricks to facilitate final exposure of the glenoid. For experienced surgeons, we analysed the tricky portions of the deltopectoral approach, comparing them with what is classically reported in the literature.

RESULTS

We describe an original technic for subscapularis reattachment after lesser tuberosity osteotomy in order to improve its stability. The medial part of the fragment is secondarily sculpted to obtain a step shape, which will be applied against the base of the prosthetic cup in a sort of "corner buttress".

CONCLUSIONS

Our work, based on our personal experience, confirms that there is no preferred single deltopectoral approach but, rather, multiple options. When embarking on this "shoulder highway", we encourage surgeons to respect the successive anatomic planes, which we believe is the only way to ensure easy and atraumatic dissection.

KEY POINTS

- The safe plane for going around the humeral head and positioning retractors is the plane of the subacromial deltoid bursa. - Always stay close to the bone during capsule release, whether on the humeral or glenoid side. - Never go medially to the conjoint tendon or its deep face.

Arthroscopic anatomic glenoid reconstruction using an autologous iliac crest bone grafting technique

BACKGROUND

Open bone block procedures for glenohumeral stabilization have been used for a long time. With the advancement of arthroscopic techniques and the development of sophisticated instruments and implants, the insertion of the bone block can be performed by an all-arthroscopic approach. The purpose of this study was to evaluate the clinical and radiologic results after an arthroscopic anatomic glenoid reconstruction using an all-arthroscopic, autologous tricortical iliac crest bone grafting technique.

MATERIALS AND METHODS

Fifteen patients (1 female and 14 male patients; mean age, 31.4 years [range, 17-49 years]) underwent reconstruction of significant glenoid defects in cases of recurrent shoulder instability by the aforementioned technique. The patients were followed up clinically (range of motion, Constant score, Rowe score, Subjective Shoulder Value, and Western Ontario Shoulder Instability Index) and radiographically (with true anteroposterior and axillary views, as well as 2-/3-dimensional computed tomography [glenoid configuration, signs of graft resorption, bone consolidation, and glenoid index]).

RESULTS

After a mean follow-up period of 20.6 months (range, 12-65 months), the Constant score averaged 85.0 points (range, 73-98 points; contralateral side, 89.6 points [range, 78-96 points]), the Rowe score averaged 88.0 points (range, 65-100 points), the Subjective Shoulder Value averaged 84.5% (range, 50%-100%), and the Western Ontario Shoulder Instability Index averaged 76.7% (range, 46%-93%). No recurrent subluxations or dislocations were observed. Radiographically, computed tomography imaging showed a consolidated autograft in all cases. The glenoid index increased from a mean of 0.77 preoperatively to 1.16 immediately postoperatively; at the time of last follow-up, the glenoid index decreased to 1.04.

CONCLUSION

The arthroscopic reconstruction of anteroinferior glenoid defects re-creates the pear-shaped anatomy of the anteroinferior glenoid and leads to good to excellent early clinical results.

Subscapularis function after transosseous repair in shoulder arthroplasty: transosseous subscapularis repair in shoulder arthroplasty

BACKGROUND

Postoperative subscapularis function has been identified as an essential factor influencing the outcome of shoulder arthroplasty. The goal of this study was an evaluation of subjective and objective subscapularis function after transosseous refixation.

METHODS

Twenty-three patients with an average age of 71 years (range, 51-86) and follow-up of 43 months (range, 24-67) were included in this study. The subscapularis was tenotomized from the lesser tuberosity and refixation was performed in a transosseous technique through bone tunnels with nonabsorbable sutures. Subscapularis function was evaluated subjectively by the ability to tuck a shirt and objectively with the lift-off test and strength measurement in internal rotation. Radiological assessment included ultrasound evaluation of the subscapularis and an axillary x-ray.

RESULTS

No complete, but 7 partial subscapularis tears were found on ultrasound (30.4%). Five patients were not able to tuck their shirt postoperatively (22.7%). This was associated with an inferior clinical outcome (American Shoulder and Elbow Surgeons [ASES] score 53.3 vs 76.4; P = .023). The lift-off test was positive in 4 patients  (17.4%), which was also associated with an inferior clinical result (Constant score 52.3% vs 74.2%; P = .021). Nineteen patients were able to go through an internal rotation strength testing in the lift-off position, and averaged 3.8 kg.

CONCLUSION

Although overall reliable refixation of the subscapularis was achieved by transosseous repair, almost 25% of patients showed signs of decreased function and 30% showed signs of partial defects. Subjective and objective functional deficits had a significant influence on the clinical outcome.

Long-term subscapularis strength assessment after Bristow-Latarjet procedure: isometric study

BACKGROUND

The subscapularis is the strongest rotator cuff muscle. Bristow-Latarjet procedure may impair subscapularis function. The aim of the study is to describe the difference in isometric subscapularis (SSC) strength after L-shape tenotomy versus muscle split in patients who underwent to Bristow-Latarjet procedure.

MATERIALS AND METHODS

From 2000 to 2006, we enrolled 376 patients for Bristow-Latarjet procedures. We identified 2 groups according to the subscapularis approach. Group A included 264 subjects with subscapularis L shape tenotomy; group B included 112 subjects with subscapularis muscle split. The subscapularis function was assessed with lift-off and belly-press tests. Isometric strength of rotator cuff muscle was assessed at an average follow-up of 45 months in group A and 42 months in group B, recording the maximum isometric peak torque (PT) (N), maximum isometric couple (Nm), relative strength index (N/Kg), strength, couple and external/internal rotator ratio. Constant and Rowe were used as scores.

RESULTS

Subscapularis assessment in the overall population showed 33 cases (8.8%) with a positive Lift-off test and 30 cases (8%) with a positive belly-press test. Rowe and Constant scores increased in both groups (P < .01). The mean PT in group A was lower of 24,8 Nw than group B (P < .01); similarly, the max PT values of group A were lower of 26.1 Nw than group B (P < .01).

CONCLUSION

L-shaped tenotomy in Bristow-Latarjet procedure has a weakening effect on the subscapularis and for these reasons we strongly recommend the muscle split approach for an optimal subscapularis function recovery.