Currently, there are a variety of different reverse shoulder implant designs but few anatomic studies to support the optimal selection of prosthetic size. This study analyzed the glenohumeral relationships of patients who underwent reverse shoulder arthroplasty (RSA). Ninety-two shoulders of patients undergoing primary RSA for a massive rotator cuff tear without bony deformity or deficiency and 10 shoulders of healthy volunteers (controls) were evaluated using three-dimensional CT reconstructions and computer aided design (CAD) software. Anatomic landmarks were used to define scapular and humeral planes in addition to articular centers. After aligning the humeral center of rotation with the glenoid center, multiple glenohumeral relationships were measured and evaluated for linearity and size stratification. The correction required to transform the shoulder from its existing state (CT scan) to a realigned image (CAD model) was compared between the RSA and control groups. Size stratification was verified for statistical significance between groups. Generalized linear modeling was used to investigate if glenoid height, coronal humeral head diameter and gender were predictive of greater tuberosity positions.Background:
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While reverse shoulder arthroplasty has shown successful outcomes for a variety of shoulder pathologies, postoperative instability continues to be one of the most common complications limiting outcomes. In the literature, reports of instability range from 2.4%–31%. Many authors recommend an initial attempt at closed reduction followed by a period of immobilization for management of the initial dislocation episode while others may seek to rule out infection or other secondary causes; however there is little data to support either practice. The purpose of this study was to evaluate the outcomes of patients with postoperative dislocation following reverse shoulder arthroplasty managed with closed reduction. A retrospective review of all reverse shoulder arthroplasties performed by a single surgeon (MF) from 2002-present was performed to identify all patients treated for postoperative dislocation treated with closed reduction, either in the office setting or under anesthesia in the operating room. A total of 21 patients were identified. Preoperative patient characteristics, implant selection, and time to initial dislocation episode were recorded. Final outcomes including recurrent instability need for revision surgery, ASES outcome score, and range of motion were evaluated.Background:
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Subchondral bone density (SBD) distribution is an important parameter regarding that may be important when considering implant stability. This parameter is a reflection of the loading experienced by the joint throughout the lifetime and may be useful in pre-surgical planning and implant design. Clinically, the question of the glenoid surface preparation for TSA/RSA remains controversial, despite numerous published studies on glenoid bone morphology. To address this question, there exists a need to develop a 3D quantitative method capable of analyzing the complex glenoid bone morphology at different depths from the surface. Computed tomographic osteoabsoptiomery (CT-OAM) evaluates SBD based on the Housfield Unit (HU) value of each pixel. In this pilot study, we aimed to analyze SBD distribution of the glenoid at different depths by means of CT-OAM in male TSA subjects. A study group of twenty male TSA patients (61–69y.o) were included in this study. Each subject obtained a pre-operative CT scan following a standardized protocol on the same CT scanner (1.25 mm slice thickness). Resultant DICOM 2D images were processed in custom-written program (VC++) and the surface of every glenoid was manually traced from the axial slices. Care was taken during the manual tracing process to exclude osteophytes and cyst formations from the resultant surface. Values of HU at every selected pixel on the surface of the glenoid were recorded. Subsequently, the layer of pixels at a 0.5 mm distance from the previous surface was virtually scraped and the HU values of new layer of pixels were recorded. This routine was repeated up to a depth of 5 mm from the glenoid surface, taking measurements on 11 virtual 3D surfaces with a thickness of 0.5 mm. Mean SBD distribution was reported for each layer and differences were compared using ANOVA and Fisher's post-hoc test.Introduction:
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While reverse shoulder arthroplasty (RSA) has shown successful outcomes for a variety of shoulder pathologies, postoperative scapula fractures continue to be one of the most common complications limiting outcomes with rates reported between 0.8–7.2%. Previous literature has shown that postoperative scapula fractures have a deleterious effect on elevation and outcomes scores, however these studies were all performed at short-term follow-up from the fracture. It has also not been shown whether postoperative scapular fractures increases risk of revision surgery. The purpose of this study was to determine the effect of postoperative scapula fracture on the outcomes following RSA at minimum 1 year follow-up from the fracture. A retrospective, case-control study of 25 nonoperatively treated postoperative scapula fractures following RSA in a single surgeon's practice was analyzed with minimum 2 year follow-up from surgery and 1 year follow-up from fracture. Patients with postoperative scapula fractures were matched 1: 4 to a control group for age, sex, total follow-up time, indication for surgery, and primary versus revision surgery. Outcome measures including revision surgery, ASES score, and change in range of motion were compared between fracture cases and controls. Radiographic features including fracture location (acromion vs. scapular spine) and healing of fracture was also analyzed with respect to outcome.Background:
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Reverse shoulder arthroplasty (RSA) has proven to be a useful tool to manage a variety of pathologic conditions. However, inconsistent improvement in motion occurs in patients who have undergone RSA for revision shoulder arthroplasty, proximal humeral fracture sequelae, and treatment of infection. Additional factors that have been suggested to produce poor postoperative range of motion (ROM) may be associated with patient's factors such as poor preoperative range of motion and surgical factors such as inability to lengthen the arm. The purpose of this study was to analyze multiple factors which may be responsible in predicting motion after RSA. It is our hypothesis that intraoperative ROM is most predictive of postoperative ROM. Between February 2003 and April 2011 566 patients (225 male and 341 female) treated with a RSA for 1) acute proximal humeral fracture (11), 2) Sequeala of proximal humeral fractures (31), 3) cuff tear arthropathy (278), 4) massive cuff tear without arthritis (78), 5) failed shoulder arthroplasty (168) and 6) infection (29) were evaluated with preoperative range of motion, intraoperative range of motion and range of motion at a minimum of 2-year postoperative follow up. A single observer recorded intraoperative flexion (IFF) in 30° increments. Preoperative and postoperative ROM was recorded by patient video or a previously validated patient performed outcome measure. Preoperative diagnosis was confirmed by radiographic and intraoperative information. 477 patients had preoperative and postoperative radiographs available for analysis of acromial-greater tuberosity distance change (AGT) which was utilized to calculate arm lengthening. A regression analysis was then performed to determine which factors were most influential in predicting postoperative active range of motion.Introduction:
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