Rotator cuff fatty infiltration and muscle atrophy: relation to glenoid deformity in primary glenohumeral osteoarthritis.

BACKGROUND: Muscle atrophy (MA) and fatty infiltration (FI) are degenerative processes of the rotator cuff musculature that have incompletely understood relationships with the development of eccentric glenoid wear in the setting of primary glenohumeral osteoarthritis (GHOA). METHODS: All patients with GHOA and an intact rotator cuff who underwent both magnetic resonance imaging and computed tomography scans of the affected shoulder prior to total shoulder arthroplasty between 2015 and 2020 were identified from a prospectively maintained registry. Rotator cuff MA was measured quantitatively on sequential sagittal magnetic resonance images, whereas FI was assessed on sagittal magnetic resonance imaging slices using the Goutallier classification. Preoperative computed tomography scans were reconstructed using automated 3-dimensional software to determine glenoid retroversion, glenoid inclination, and humeral head subluxation. Glenoid deformity was classified according to the Walch classification. Univariate and multivariable regression analyses were performed to characterize associations between age, sex, muscle area, FI, and glenoid morphology. RESULTS: Among the 127 included patients, significant associations were found between male sex and larger overall rotator cuff musculature (P < .01), increased ratio of the posterior rotator cuff (PRC) to the subscapularis area (P = .01), and glenoid retroversion (19° vs. 14°, P < .01). Larger supraspinatus and PRC muscle size was correlated with increased retroversion (r = 0.23 [P = .006] for supraspinatus and r = 0.25 [P = .004] for PRC) and humeral head subluxation (r = 0.25 [P = .004] for supraspinatus and r = 0.28 [P = .001] for PRC). The ratio of PRC muscle size to anterior rotator cuff muscle size was not associated with evidence of eccentric glenoid wear (P > .05). After we controlled for confounding factors, increasing glenoid retroversion was associated with high-grade infraspinatus FI (ß, 6.8; 95% confidence interval, 2.9-10.7; P < .01) whereas larger PRC musculature was predictive of a Walch type B (vs. type A) glenoid (odds ratio, 1.3; 95% confidence interval, 1.0-1.5; P = .04). CONCLUSION: Patients with eccentric glenoid wear in the setting of primary GHOA and an intact rotator cuff appear to have both larger PRC musculature and higher rates of infraspinatus FI. Although the temporal and causal relationships of these associations remain ambiguous, MA and FI should be considered 2 discrete processes in the natural history of GHOA.

Visibility of Tinted Chlorhexidine Gluconate Skin Preparation on Varied Skin Pigmentations.

Preoperative skin preparation with antimicrobial agents decreases the risk of surgical site infection, but concerns have been raised about the visibility of a common surgical preparatory agent (ChloraPrep; Becton, Dickinson & Co, Franklin Lakes, New Jersey), depending on skin pigmentation. Poor visibility may lead to failure to identify inadequately prepared skin, increasing the risk of surgical site infection. This study was conducted to determine whether different tints of ChloraPrep and different skin pigmentations affect the ability of orthopedic surgeons to identify the adequacy of skin preparation. The forearms of volunteers in 4 skin pigmentation categories (fair, medium-fair, medium-dark, and dark) were prepared with Hi-Lite Orange and Scrub Teal ChloraPrep, with 1 forearm prepared adequately and 1 prepared inadequately. Videos showing the forearms were obtained and compiled into a survey that was sent to orthopedic surgeons, who were asked to assess the adequacy of skin preparation. When the 4 pigmentation categories were aggregated, no difference was noted between Hi-Lite Orange and Scrub Teal tints in rates of correct identification of adequate skin preparation by respondents. When the preparation tint was not controlled for, respondents correctly identified the adequacy of skin preparation for fair and medium-fair pigmentations, but not for medium-dark and dark skin pigmentations. The Hi-Lite Orange tint was significantly easier to identify on fair and medium-fair skin pigmentations, and the Scrub Teal tint was easier to identify on medium-dark and dark skin pigmentations. To reduce the risk of surgical site infection, surgeons should use Hi-Lite Orange on patients whose skin is fair or medium-fair and Scrub Teal on patients whose skin is medium-dark or dark. [Orthopedics. 2017; 40(1):e44-e48.].

Osteochondritis dissecans of the elbow.

Capitellar osteochondritis dissecans (OCD) can be a significant problem in adolescent overhead athletes. The cause is likely multifactorial secondary to repetitive stresses, biomechanical mismatch, and a tenuous vascular supply of the capitellum. Recent literature reveals that the prevalence is likely higher than previously thought. This, in conjunction with increased levels of athletic competition in children at younger ages, has fed the recent interest in this topic. The literature continues to show that non-operative treatment is still successful for stable lesions. Unstable lesions, therefore, have been the focus of the new literature regarding operative management and outcomes. The aim of this paper is to provide a summary of current literature and an up-to-date approach to the diagnosis, evaluation, and treatment of osteochondritis dissecans of the capitellum.