The influence of radiographic markers of biomechanical variables on outcomes in reverse shoulder arthroplasty.

BACKGROUND: Controversy exists in reverse total shoulder arthroplasty in regard to variability in the center of rotation (COR), which modifies the superior-inferior position of the humerus to affect the acromiohumeral interval (AHI), and its effect on the deltoid lever arm (DLA), acromial index (AI), and critical shoulder angle (CSA). The purpose of this study was to investigate the variation in biomechanics and the association with patient-reported outcomes (PROs) and range of motion (ROM) measurements. METHODS: Radiographs, ROM, and 2-year PRO scores were retrospectively reviewed for 108 patients. RESULTS: There was large variability in preoperative and postoperative biomechanics. The COR was medialized 12.01 ± 4.8 mm. The CSA increased 2.64° ± 12.45°. The AHI increased 20.6 ± 9.80 mm. The DLA lengthened 21.21 ± 10.15 mm. The AI increased 0.009 ± 0.3. Postoperative AI positively correlated with American Shoulder and Elbow Surgeons score and Penn Shoulder Score (P = .03). Specifically, a postoperative AI of 0.62 corresponded to American Shoulder and Elbow Surgeons score (72.5 ± 18.3 vs. 62.3 ± 24.7; P = .02) and Penn Shoulder Score (71.2 ± 21.4 vs. 61.8 ± 25.6; P = .05), an average 10 points higher than AI of <0.6. Also, a smaller postoperative CSA (<25°) correlated with improved forward elevation (P = .02). CONCLUSIONS: This is the first study that evaluates the variability of biomechanical factors and their impact on postoperative ROM and PROs. An increased AI and decreased CSA are associated with improved PROs in this study, and a smaller CSA is associated with better forward elevation. Change in the COR, AHI, or DLA, however, did not affect patient outcomes or ROM. Further study is warranted to determine the optimal position.

Subscapularis Repair Is Unnecessary After Lateralized Reverse Shoulder Arthroplasty.

BACKGROUND: Controversy exists as to whether the subscapularis should be repaired after reverse shoulder arthroplasty. The purpose of the present study was to evaluate the utility of repairing the subscapularis after reverse shoulder arthroplasty with regard to complications, objective findings, and patient-reported outcome measures. METHODS: We retrospectively reviewed the records for 99 patients who had undergone a lateralized reverse shoulder arthroplasty with (n = 58) or without (n = 41) subscapularis repair. Outcomes were compared with the Single Assessment Numeric Evaluation (SANE), Penn shoulder score (PSS), Veterans RAND (VR)-12, and American Shoulder and Elbow Surgeons (ASES) score at a minimum of 2 years of follow-up. Demographics, range of motion, and complications were also compared. A 1-way analysis of variance was performed to determine differences in performance and outcome scores, and a chi-square analysis was performed to compare the frequency of complications between groups. RESULTS: There were no significant differences between the repair and no-repair groups in terms of SANE, PSS, ASES, or VR-12 scores. There also were no significant differences between the 2 groups in terms of postoperative ranges of forward elevation (128° versus 123°; p = 0.44) and external rotation (33° versus 29°; p = 0.29), the dislocation rate (5% versus 2%; p = 0.49), or the overall complication rate (9% versus 5%; p = 0.47). CONCLUSIONS: The results of the present study suggest that repair of the subscapularis tendon after lateralized reverse shoulder arthroplasty may not be necessary. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Nonoperative management versus reverse shoulder arthroplasty for treatment of 3- and 4-part proximal humeral fractures in older adults.

BACKGROUND: The treatment of 3- and 4-part proximal humeral fractures in the older adult is controversial. No study has directly compared reverse shoulder arthroplasty (RSA) with nonoperative treatment for these fractures. The purpose of this study was to compare clinical and patient-reported outcomes between RSA and nonoperative treatment groups. METHODS: A retrospective review was performed on all 3- and 4-part proximal humeral fractures treated with either RSA or nonoperative treatment with minimum 1-year follow-up. All patients in the nonoperative cohort were offered RSA but declined. Objective patient data were obtained from medical records. Patient-reported outcomes including visual analog scale score, Single Assessment Numeric Evaluation score, Penn Shoulder Score, American Shoulder and Elbow Surgeons score, resiliency score, and Veterans Rand-12 scores were obtained at follow-up. Statistical analysis was performed by use of the Student t test for continuous variables and χ2 analysis for nonparametric data. RESULTS: We analyzed 19 nonoperative and 20 RSA patients with a mean follow-up period greater than 2 years (29 months in nonoperative group and 53 months in RSA group). There were no differences in range of motion between groups (forward elevation, 120° vs 119° [P = .87]; external rotation, 23° vs 31° [P = .06]). No differences between the nonoperative and RSA groups were noted for any patient-reported outcomes. Among patients receiving RSA, there was no difference in outcomes in those undergoing surgery less than 30 days after injury versus those receiving delayed RSA. CONCLUSIONS: This study suggests that there are minimal benefits of RSA over nonoperative treatment for 3- and 4-part proximal humeral fractures in older adults.

Outcomes of total shoulder arthroplasty in patients younger than 65 years: a systematic review.

BACKGROUND: Despite concerns about the longevity of total shoulder arthroplasty (TSA) in young patients, it remains an attractive option because of the absence of superior options. METHODS: A systematic review was performed using searches of PubMed, Embase, and Cochrane databases. English-language studies were identified with search terms "total shoulder arthroplasty" (title/abstract) or "shoulder replacement" (title/abstract) and "young" (title/abstract) or "under 65 years of age" (title/abstract). Duplicate studies, studies not reporting outcomes, and those using a humeral resurfacing technique were excluded. Outcomes of interest included pain, range of motion, patient-reported outcome scores, patient satisfaction, radiographic changes, complication and revision rates, and implant survival. RESULTS: Six studies met inclusion criteria. Significant improvements in pain, range of motion, and patient-reported outcomes were found across all studies that reported these measures. At an average of 9.4 years, 17.4% underwent revision and 54% had glenoid lucency. Whereas glenoid loosening is the most common reason for revision (52%), overall implant survivorship was reported at 60% to 80% at 10- to 20-year follow-up. Outcome measures including the Constant, American Shoulder and Elbow Surgeons, and Simple Shoulder Test scores were reported, with generally satisfactory but not excellent results between 3 and 10 years from surgery. CONCLUSIONS: Although there is concern with periprosthetic radiolucency and glenoid loosening in the young patient (<65 years) undergoing TSA, overall low revision rates and high implant survivorship are reported in the current literature. Whereas the patient-reported outcomes are inferior to those of the overall TSA population, there is significant improvement from baseline levels in young patients with glenohumeral arthritis.