Few studies have evaluated the relationship between patients’
pre-operative expectations and the outcome of orthopaedic procedures.
Our aim was to determine the effect of expectations on the outcome
after primary anatomical total shoulder arthroplasty (TSA). We hypothesised
that patients with greater expectations would have better outcomes. Patients undergoing primary anatomical TSA completed the Hospital
for Special Surgery’s Shoulder Expectations Survey pre-operatively.
The American Shoulder and Elbow Surgeons (ASES), Shoulder Activity
Scale (SAS), Short-Form-36 (SF-36), and visual analogue scale (VAS)
for pain, fatigue, and general health scores were also collected
pre-operatively and two years post-operatively. Pearson correlations
were used to assess the relationship between the number of expectations
and the outcomes. Differences in outcomes between those with higher
and lower levels of expectations for each expectation were assessed
by independent samples Aims
Patients and Methods
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
Reverse total shoulder replacement (RTSR) depends
on adequate deltoid function for a successful outcome. However, the
anterior deltoid and/or axillary nerve may be damaged due to prior
procedures or injury. The purpose of this study was to determine
the compensatory muscle forces required for scapular plane elevation
following RTSR when the anterior deltoid is deficient. The soft
tissues were removed from six cadaver shoulders, except for tendon
attachments. After implantation of the RTSR, the shoulders were
mounted on a custom-made shoulder simulator to determine the mean
force in each muscle required to achieve 30° and 60° of scapular
plane elevation. Two conditions were tested: 1) Control with an
absent supraspinatus and infraspinatus; and 2) Control with anterior
deltoid deficiency. Anterior deltoid deficiency resulted in a mean
increase of 195% in subscapularis force at 30° when compared with
the control (p = 0.02). At 60°, the subscapularis force increased
a mean of 82% (p <
0.001) and the middle deltoid force increased
a mean of 26% (p = 0.04). Scapular plane elevation may still be possible following an RTSR
in the setting of anterior deltoid deficiency. When the anterior
deltoid is deficient, there is a compensatory increase in the force
required by the subscapularis and middle deltoid. Attempts to preserve
the subscapularis, if present, might maximise post-operative function.
