Kinematic analysis of dynamic shoulder motion in patients with reverse total shoulder arthroplasty.

BACKGROUND: Reverse total shoulder arthroplasty (rTSA) has been used to treat patients with irreparable rotator cuff dysfunction. Despite the proven clinical efficacy, there is minimal information regarding the underlying changes to the shoulder kinematics associated with this construct. Therefore, we sought to examine the kinematics of dynamic shoulder motion in patients with well-functioning rTSA. METHODS: We tested 12 healthy subjects and 17 patients with rTSA. All rTSA patients were able to elevate their arms to at least 90° and received the implant as the primary arthroplasty at least 6 months before testing. On average, the rTSA patients elevated their arms to 112° ± 12° (mean ± SD) and reported an American Shoulder and Elbow Surgeons outcome score of 90.6 ± 6.3. A 3-dimensional electromagnetic motion capture device was used to detect the dynamic motion of the trunk, scapula, and humerus during bilateral active shoulder elevation along the sagittal, scapular, and coronal planes. RESULTS: In both healthy and rTSA shoulders, the majority of the humeral-thoracic motion was provided by the glenohumeral motion. Therefore, the ratio of glenohumeral to scapulothoracic (ST) motion was always greater than 1.62 during elevation along the scapular plane. In comparison to healthy subjects, however, the contribution of ST motion to overall shoulder motion was significantly increased in the rTSA shoulders. This increased contribution was noted in all planes of shoulder elevation and was maintained when weights were attached to the arm. CONCLUSION: Kinematics of the rTSA shoulders are significantly altered, and more ST motion is used to achieve shoulder elevation.

Reverse shoulder arthroplasty for the treatment of irreparable rotator cuff tear without glenohumeral arthritis.

BACKGROUND: The purpose of the present study was to evaluate the indications for, and outcomes of, reverse shoulder arthroplasty in patients with massive rotator cuff tears but without glenohumeral arthritis. METHODS: From December 1998 to December 2006, sixty-nine patients (seventy-two shoulders) were managed with reverse shoulder arthroplasty for the treatment of irreparable rotator cuff dysfunction without glenohumeral arthritis. The indications for reverse shoulder arthroplasty were persistent shoulder pain and dysfunction despite a minimum of six months of nonoperative treatment, the presence of at least a two-tendon tear, and Hamada stage-1, 2, or 3 changes in a patient for whom a non-arthroplasty option did not exist. Fifty-eight patients (sixty shoulders) had a minimum of two years of follow-up. Thirty-four shoulders had had no previous surgery (Group A), and twenty-six shoulders had had at least one previous surgical procedure (Group B). Postoperatively, patients were prospectively followed both clinically and radiographically. Survival analysis was performed, with the end points being removal or revision of the implant, radiographic loosening, and declining American Shoulder and Elbow Surgeons score. RESULTS: Common characteristics of patients managed with reverse shoulder arthroplasty in this study were pain and (1) <90° of arm elevation at the shoulder without anterosuperior escape (n = 40; 66.6%); (2) <90° of elevation with anterosuperior escape (n = 16; 26.7%); or (3) irreparable rotator cuff tear and pain with >90° of elevation (n = 4; 6.7%). The average duration of follow-up was fifty-two months (range, twenty-four to 101 months). All measured outcomes improved postoperatively. For all patients, the average American Shoulder and Elbow Surgeons score improved from 33.3 to 75.4 (p < 0.0001), the average Simple Shoulder Test score improved from 1.6 to 6.5 (p < 0.0001), the average visual analog score for pain improved from 6.3 to 1.9 (p < 0.0001), the average visual analog score for function improved from 3.2 to 7.1 (p < 0.0001), the average forward flexion improved from 53° to 134° (p < 0.0001), the average abduction improved from 49° to 125° (p < 0.0001), the average internal rotation improved from S1 to L2 (p < 0.0001), and the average external rotation improved from 27° to 51° (p = 0.001). There were a total of twelve complications in eleven patients (prevalence, 20%). The survivorship at a mean of fifty-two months (range, twenty-four to 101 months) was 90.7% for all patients, 91.8% for Group A, and 87% for Group B. CONCLUSIONS: When non-arthroplasty options either have failed or have a low likelihood of success, reverse shoulder arthroplasty provides reliable pain relief and return of shoulder function in patients with massive rotator cuff tears without arthritis at the time of short to intermediate-term follow-up.

Effects of acquired glenoid bone defects on surgical technique and clinical outcomes in reverse shoulder arthroplasty.

BACKGROUND: Reverse total shoulder arthroplasty is the accepted method of treatment for selected shoulder disorders. The purpose of this study was to compare primary reverse shoulder arthroplasty surgical techniques as well as clinical and radiographic outcomes in patients with acquired glenoid bone defects and in those with normal glenoid morphology. METHODS: Preoperative three-dimensional computed tomography scans were performed on 216 shoulders in 211 patients undergoing primary reverse shoulder arthroplasty between 2004 and 2007. The glenoids were classified as normal or abnormal on the basis of preoperative radiographs and three-dimensional reconstructions of the scapula. One hundred and forty-three shoulders had been followed for two years. There were eighty-seven normal and fifty-six abnormal glenoids. The surgical techniques that were compared included bone-grafting and glenosphere selection. The clinical outcomes for the two groups were compared with respect to the American Shoulder and Elbow Surgeons score. RESULTS: Surgical technique differed between the groups. All fifty-six glenoids with acquired bone defects had center screw placement along an alternative (scapular spine) centerline. A bone graft was used in twenty-two shoulders with acquired glenoid bone defects compared with none of those with normal glenoid morphology (p = 0.016). Shoulders with glenoid defects were treated with larger glenospheres (36 or 40 mm) more often than those with normal glenoids (p < 0.001). No significant difference was detected between the groups with regard to the preoperative or postoperative American Shoulder and Elbow Surgeons scores. Radiographs did not demonstrate failure or resorption of a glenoid bone graft when present. All outcomes improved significantly postoperatively. There were five complications, and one patient was unsatisfied with the result. CONCLUSIONS: Glenoid bone defects, when managed with an alteration of surgical technique, including bone-grafting when indicated, are not a contraindication to reverse total shoulder arthroplasty.

Reverse shoulder arthroplasty in patients with rheumatoid arthritis.

BACKGROUND: The purpose of this study was to describe the pathoanatomy of patients diagnosed with rheumatoid arthritis and rotator cuff deficiency and report their outcomes following reverse shoulder arthroplasty. METHODS: Twenty-one shoulders were evaluated prospectively. Nine had no prior surgery, 9 had a failed rotator cuff repair, and 3 had a failed arthroplasty. Patients were followed for a minimum of 2 years (average, 36 months). All patients had preoperative radiographs and 19 shoulders had an MRI or CT available for evaluation of muscular and bony deficiency. Radiographs at most recent follow-up were evaluated for loosening and scapular notching. RESULTS: All outcome measures improved significantly: ASES scores improved from 28 preoperatively to 82 postoperatively (P < .0001); SST scores improved from 1 to 7 (P < .0001); VAS pain scores improved from 7 to 1 (P < .0001); VAS function scores improved from 3 to 6 (P=.0058); elevation improved from 52° to 126° (P < .0001); abduction improved from 55° to 116° (P=.0002); external rotation improved from 19° to 33° (P=.02); and internal rotation improved from S1 to L4 (P=.02). Twelve patients rated their outcome as excellent, 6 as good, 2 as satisfactory, and 1 as unsatisfactory. Severe glenoid erosion was seen in 10 of the shoulders and 5 of the defects required structural grafting. Three patients (14%) sustained a complication that required reoperation: 2 for infection and 1 for periprosthetic fracture. CONCLUSIONS: In patients with rheumatoid arthritis and rotator cuff deficiency, reverse shoulder arthroplasty can provide improvement in function and decreased pain.

Is a formal physical therapy program necessary after total shoulder arthroplasty for osteoarthritis?

HYPOTHESIS: A retrospective analysis was conducted of 2 consecutive groups of patients undergoing total shoulder arthroplasty (TSA) for primary osteoarthritis. One group was treated with formal physical therapy (PT), and one group was treated with home-based, physician-guided PT. We hypothesized that patients with a formal postoperative PT protocol would have significantly better postoperative clinical outcomes than patients with no formal PT. METHODS: Group A (43 patients) had a standard PT program. Group B (38 patients) had a home-based, physician-guided PT program. Clinical outcomes (preoperatively, 3, 6, and 12 months and most recent follow-up) were analyzed. A minimum sample size of 31 patients gives power to detect a 10-point American Shoulder and Elbow Surgeons (ASES) score (alpha=0.05, beta=0.80). RESULTS: ASES and Simple Shoulder Test (SST) scores significantly improved in both groups at all follow-up periods. Forward flexion and abduction were significantly improved in group B at all time points, whereas an initial improvement in forward flexion and abduction in group A was lost at final follow-up. There were no significant differences in final ASES or SST scores between groups at final follow-up. However, forward flexion, abduction, and the Short Form-36 physical component summary in group B were significantly better than group A at final follow-up. No significant improvements in internal rotation or SF-36 mental component summary were seen within or between the groups at final follow-up. Overall, there was no difference in patient satisfaction, with 88% satisfaction in group A and 95% satisfaction in group B (chi(2)=0.471, P=.4924). CONCLUSIONS: A home-based, physician-guided therapy program may provide adequate rehabilitation after TSA, allowing for a reduction in cost for the overall procedure.