There is a high prevalence of obesity in the United States and the numbers are increasing. These patients comprise a significant portion of the shoulder arthroplasty patient population. There are several reports of outcomes in the literature on obese patients after total knee or hip replacement, however, this data is lacking in the shoulder arthroplasty patient population. The purpose of this study is to compare the functional outcomes and complications of obese patients undergoing shoulder arthroplasty with the non-obese population. Between 2009 to 2010, 76 patients that had a primary total shoulder replacement were grouped according to their Body Mass Index (BMI) and followed prospectively for 2 years. The groups were divided as normal (BMI <25, N=26), overweight (25 to 30 BMI, N=25), and obese (>30 BMI, N=25) according to the World Health Organization classifications. Preoperative demographics, age, comorbidities and postoperative complications were recorded. Perioperative operating room and hospital data were analyzed. Functional outcome measurements including ASES, SF-36 physical component (PC) scores, mental component (MC) scores and visual analog scale along with general health and fatigue were evaluated at the 0 and 2 year time period. Statistical analyses were performed.Introduction
Methods
While shoulder elevation can be reliably restored following reverse total shoulder arthroplasty (RTSA), patients may experience a loss of internal and external rotation. Several recent studies have investigated scapular notching and have made suggestions regarding glenosphere placement in order to minimize its occurrence. However, very few studies have looked at how changes in glenosphere placement in RTSA affect internal and external rotation. The purpose of this study was to determine the effect of glenosphere position on internal and external rotation range of motion at various degrees of scaption following RTSA. We hypothesized that alteration in glenosphere position will affect the amount of impingement-free internal and external rotation. CT scans of the scapula and humerus were obtained from seven cadaver specimens and 3-Dimensional (3D) reconstructions were created. A corresponding 3D RTSA model was created by laser scanning the baseplate, glenosphere, humeral stem and bearing. The RTSA models were then virtually implanted into each specimen. The glenosphere position was determined in relation to the neutral position in 6 different settings: Medialization (5 mm), lateralization (10 mm), superior translation (6mm), inferior translation (6 mm), superior tilt (20°), and inferior tilt (15° and 30°). The humerus in each virtual model was allowed to freely rotate at a fixed scaption angle until encountering bone-bone or bone-implant impingement (180 degrees of limitation). Each model was tested at 0, 20, 40, and 60 degrees of scaption and the impingement-free internal and external rotation range of motion for each scaption angle was recorded.Introduction
Methods
