The Walch Type B2 glenoid has the hallmark features of posteroinferior glenoid erosion, retroversion, and posterior humeral head subluxation. Although our understanding of the pathoanatomy of bone loss and its evolution in Type B's has improved, the etiology remains unclear. Furthermore, the morphology of the humerus in Walch B types has not been studied. The purpose of this imaging based anthropometric study was to examine the humeral torsion in Walch Type B2 shoulders. We hypothesized that there would be a compensatory decrease in humeral retroversion in Walch B2 glenoids. Three-dimensional models of the full length humerus were generated from computed tomography data of normal cadaveric (n = 59) and Walch Type B shoulders (n = 59). An anatomical coordinate system referencing the medial and lateral epicondyles was created for each model. A simulated humeral head osteotomy plane was created and used to determine humeral version relative to the epicondylar axis and the head-neck angle. Measurements were repeated by two experienced fellowship-trained shoulder surgeons to determine inter-rater reliability. Glenoid parameters (version, inclination and 2D critical shoulder angle) and posterior humeral head subluxation were calculated in the Type B group to determine the pathologic glenohumeral relationship. Two-way ANOVAs compared group and sex within humeral version and head-neck angle, and intra-class correlation coefficients (ICCs) with a 2-way random effects model and absolute agreement were used for inter-rater reliability.Introduction
Methods
The aim of this study was to prospectively assess the results of a preoperative surgical safety checklist by comparing the initial phase of implementation of the Time Out Procedure (TOP) to the results four years later. We compared the accuracy and acceptance of the TOP to determine whether surgical practice had changed. The TOP was initiated for all elective surgical procedures performed in Christchurch in 2004. An initial audit from September 2004 – April 2005 (Phase 1) was compared to one from October 2008-September 2009 (Phase 2) looking for an improvement in completion of the procedure. Variances were recorded and analysed within the categories of 1 System and process 2 Consent and limb marking 3Incorrect details and 4 Near miss. A questionnaire was also sent to all the surgeons to determine their attitude towards the TOP. Although the TOP was completed more often in Phase 2 (98%, p<0.001) there were more variances (9%, p<0.001). The commonest variance was due to the surgeon and assistant not being present at the TOP which was significantly worse than in Phase 1 (p<0.0001). The results of the surgeon questionaire showed that only 88% agreed that the TOP was valuable in preventing wrong site surgery. This surgical indifference to the TOP is difficult to explain especially when National and International agencies have stressed its role in preventing surgical error. The recent introduction of the expanded WHO Checklist should be ‘surgeon led’ to be effective.
