Purpose: The objectives of this study were:

to determine if the deltoid, conjoint tendon and long head of the triceps provide sufficient soft tissue tension to stabilize a RTSA, and;

The hypotheses were:

that the deltoid, conjoint tendon and long head of the triceps provide sufficient soft tissue tension to stabilize a RTSA, and;

Method: Six cadaveric shoulders had all capsule, rotator cuff, and scapulohumeral muscles removed, leaving only the deltoid, conjoint tendon (i.e. coracobrachialis and short head of biceps) and long head of triceps. A RTSA was then performed. A displacing force was then applied perpendicular to the centerline of the humeral socket and this load was increased until dislocation occurred. The load required to cause a dislocation was recorded for superior, inferior, anterior and posterior load directions. This was repeated to measure the effect of humeral component rotation (neutral, 20 degrees retroversion, 20 degrees anteversion), arm position (0 degrees abduction, 60 degrees flexion, 60 degrees abduction and 60 degrees extension) and polyethylene thickness (3, 6 or 9 mm). Statistical analysis used an ANOVA with Tukey post-hoc tests for multiple comparisons (p< 0.05).

Results: The deltoid, conjoint tendon and long head of the triceps provide sufficient soft tissue tension to stabilize a RTSA. The required dislocation force was increased for an inferior direction of load application (p0.05). The required dislocation force was least in an arm position of 60 degrees abduction, followed by 60 degrees extension, with no difference between 0 degrees abduction and 60 degrees flexion (p0.05).

Conclusion: The deltoid, conjoint tendon and long head of the triceps provide sufficient soft tissue tension to stabilize a RTSA. Stability of a RTSA was greatest for an inferior directed force and an arm position of 0 degrees abduction or 60 degrees flexion. There was no influence of arm rotation or polyethylene thickness on stability of a RTSA. This study indicates that stability of a RTSA can still be achieved despite significant soft tissue loss, as long as key soft tissue structures remain intact. As well, certain loading directions and arm positions lead to an increased risk of instability. However, further in vivo studies are required.

Purpose: The objective of this study was to analyze the clinical results of arthroscopic release for the treatment of shoulder stiffness and to report the results according to etiology.

Method: Thirty cases were reviewed in 29 patients with a mean age of 48 years [range, 25–75]. The mean time from diagnosis to surgery was 37.5 months [range, 6–120]. The stiffness was considered idiopathic (i.e. frozen shoulder) (10 cases), post-traumatic (eight cases) or post-surgical (12 cases). The release consisted of 14 rotator interval resections, four anterior capsulotomies, 20 anterior and inferior capsulotomies, three tenotomies of the superior portion of the subscapularis, and 11 biceps tenotomies or tenodeses. In 26 cases, associated extra-articular procedures were also performed, including 22 subacromial bursectomies and four acromioplasties. Patients were reviewed at a mean follow-up of 44 months [range, 12–99].

Results: Eighty-nine percent were satisfied or very satisfied. The mean Subjective Shoulder Value was 76%. The mean Constant score increased from 40 ± 13 points preoperatively to 74 ± 16 points postoperatively (p< 0.05).

Conclusion: Arthroscopic shoulder release is effective for pain relief and improved function. The recovery of motion is better in idiopathic stiffness (i.e. frozen shoulder) than in post-traumatic and post-surgical stiffness. Resection of the rotator interval seems effective to restore external rotation and elevation.

Purpose: Partial rotator cuff tears are a frequent source of shoulder pain. At times, diagnosis is difficult and treatment unsuccessful. Historical treatment has involved open debridement when conservative treatment has failed. The purpose of this study was to evaluate the results of arthroscopic treatment of deep partial thickness tears of the supraspinatus tendon in patients over 40 years and to assess the healing radiographically.

Method: Forty-nine patients (mean age: 55 years) underwent treatment of a deep partial thickness tear of the supraspinatus tendon. Exclusion criteria: age < 40 years, associated instability, posterosuperior impingement or previous shoulder surgery. Patients were re-examined with a mean 32 months follow-up. For lesions involving less than 50% of the tendon thickness, an acromioplasty and either a debridement (n=39) or a side-to-side repair (n=3) was performed. For lesions involving greater than 50% of the tendon thickness (n=7), an acromioplasty and a trans-osseous repair was performed after completion of the tear. Twenty patients (41%) had an assessment of tendon healing by CT arthrogram, MRI or MR arthrogram, at a minimum 12 months post-operatively.

Results: Results were good or excellent in 90% of patients, and 94% were satisfied. The Constant score improved from 56 to 82 points (p< 0.0001) and the UCLA score improved from 15 to 30 points (p< 0.0001). Of the 31 patients employed preoperatively, three did not return to work; an occupational injury was predictive of a lower Constant score (p=0.02). Four out of 13 (31%) cases involving less than 50% of the tendon thickness healed and all cases (n=7) involving greater than 50% had healed.

Conclusion: Patients over 40 years with an isolated deep partial thickness tear of the supraspinatus tendon benefited both subjectively and objectively from arthroscopic intervention. For deep tears involving < 50% of the tendon thickness, resolution of pain and return to work is possible after acromioplasty and debridement. For deeper tears, completion of the tendon and reattachment to the greater tuberosity enables tendon healing.

Purpose: The reverse shoulder arthroplasty (RSA) is becoming increasingly common and the indications expanded. The objective of this study is to report the indications and results of RSA in a large multicenter study.

Method: A retrospective, multicenter study was conducted including all RSA implanted between 1992 and 2002 in five centers in France. Of 457 patients involved in this study, 243 patients (53%) had cuff pathology: 149 had cuff tear arthropathy, 48 had massive cuff tears, and 45 had failed cuff surgery. Ninety-nine (22%) had revision of a previous arthroplasty. Sixty (13%) had fracture-related problems. Twenty-six (6%) had osteoarthritis and two percent each had rheumatoid arthritis, tumors or other conditions. Three hundred and eighty-nine (85%) shoulders were available for review at a mean follow-up of 44 months (range, 24–142). The average age at review was 76 years (range, 22–92).

Results: Overall, significant improvement was noted in Constant scores for pain (3.5 to 12.1), activity (5.8 to 15.1), mobility (12.1 to 24.5) and strength (1.3 to 6.1) (p< 0.0001). Active elevation improved (p< 0.0001), but active internal and external rotation did not. The results were dependent on the indication. Cuff tear arthropathy had the best results while revision procedures had the worst. Young age, preoperative stiffness, teres minor deficiency, tuberosity non-union and preoperative complaints of pain rather than loss of function tended to be associated with inferior results. The deltopectoral approach tended toward greater active elevation but greater risk of instability. Survivorship to the endpoints of revision and loosening was better for patients with cuff tear pathology than for patients with failed prior hemiarthroplasty. The functional results were noted to deteriorate progressively after six years in the cuff tear pathology group, after five years in the revision hemiarthroplasty group, after three years in the osteoarthritis group, and after one year in the revision total shoulder arthroplasty group.

Conclusion: Overall results of RSA are satisfactory and predictable. Functional results improved with improved active elevation, but no improvement in active internal and external rotation. However, results are dependent on etiology.

Purpose: Reverse shoulder arthroplasty (RSA) is becoming increasingly common for a variety of indications. The most common postoperative complication is instability. The objectives of this study are to describe causes of RSA instability and preventive and treatment recommendations.

Method: All members of the American Shoulder and Elbow Society were asked for cases of RSA instability. We retrospectively reviewed 52 cases in 52 patients, performed by 13 surgeons. The mean age was 67.5 years (range, 36–83). The mean follow-up was 32.7 months (range, 3–43).

Results: The etiology included: cuff tear arthropathy (14 patients); revision arthroplasty (13 patients); fracture sequelae (6 patients); and other (6 patients). Twenty-four patients had previous shoulder surgery. All patients had a deltopectoral approach. Anterior deltoid deficiency was noted in 3 cases. Subscapularis insufficiency was noted in 27 cases. Humeral component dissociation occurred in 2 patients. The instability was: anterior (27 patients); posterior (5 patients); or inferior (3 patients). Instability occurred: in the first 48 hours (10 cases); between 2 to 30 days (13 cases); or after one month (12 cases). Causes of instability included: inadequate soft-tissue tension (23 patients); a large antero-inferior release (22 patients); subscapularis insufficiency (7 patients); hematoma (2 patients); trauma (2 patients), deltoid insufficiency (2 patients); glenosphere malposition (2 patients); acromion fracture (2 patients); and other (4 patients). Initial treatment included: non-operative (6 patients); closed reduction (23 patients); open reduction (3 patients); and revision arthroplasty (11 patients). Final outcomes included: persistent instability (7 patients); humeral revision (19 patients); glenoid revision (one patient); hemiarthroplasty (3 patients); and resection arthroplasty (2 patients).

Conclusion: Main causes of RSA instability include inadequate soft tissue tension, large anteroinferior release and subscapularis insufficiency. Preventive measures include careful patient selection, restoration of humeral length, minimizing anteroinferior releases, maximizing soft-tissue tension, maintaining or restoring subscapularis integrity, immobilization in the case of subscapularis insufficiency and use of a postoperative drain. Treatment recommendations include restoration of humeral length, soft-tissue retensioning and prolonged immobilization.

This study compared the effect of a computer-assisted and a traditional surgical technique on the kinematics of the glenohumeral joint during passive abduction after hemiarthroplasty of the shoulder for the treatment of fractures. We used seven pairs of fresh-frozen cadaver shoulders to create simulated four-part fractures of the proximal humerus, which were then reconstructed with hemiarthroplasty and reattachment of the tuberosities. The specimens were randomised, so that one from each pair was repaired using the computer-assisted technique, whereas a traditional hemiarthroplasty without navigation was performed in the contralateral shoulder. Kinematic data were obtained using an electromagnetic tracking device.

The traditional technique resulted in posterior and inferior translation of the humeral head. No statistical differences were observed before or after computer-assisted surgery.

Although it requires further improvement, the computer-assisted approach appears to allow glenohumeral kinematics to more closely replicate those of the native joint, potentially improving the function of the shoulder and extending the longevity of the prosthesis.