Background. The purpose of this study was to determine if thresholds regarding the percentage of maximal improvement in the Simple Shoulder Test (SST) and American Shoulder and Elbow Surgery (ASES) score exist that predict “excellent” patient s­atisfaction (PS) following reverse total shoulder arthroplasty (RSA). Methods. Patients undergoing RSA using a single implant system were evaluated pre-operatively and at a minimum 2-year follow-up. Receiver-operating-characteristic (ROC) curve analysis determined thresholds to predict “excellent” PS by evaluating the percentage of maximal improvement for SST and ASES. Pre-operative factors were analyzed as independent predictors for achieving SST and ASES thresholds. Results. 198 (SST) and 196 (ASES) patients met inclusion criteria. For SST and ASES, ROC analysis identified 61.3% (p<.001) and 68.2% (p<.001) maximal improvement as the threshold for maximal predictability of “excellent” satisfaction respectively. Significant positive correlation between the percentage of maximum score achieved and “excellent” PS for both groups were found (r=.440, p<.001 for SST score; r=0.417, p<.001 for ASES score). Surgery on the dominant hand, greater baseline VAS Pain, and cuff arthropathy were independent predictors for achieving the SST and ASES threshold. Conclusion. Achievement of 61.3% of maximal SST score improvement and 68.3% of maximal ASES score improvement represent thresholds for the achievement of “excellent” satisfaction following RSA. Independent predictors of achieving these thresholds were dominant sided surgery and higher baseline pain VAS scores for SST, and rotator cuff arthropathy for ASES. Keywords. Percentage of maximal improvement; Predictors; American Shoulder and Elbow Surgery Score; Simply Shoulder Test; Reverse shoulder Arthroplasty; Satisfaction. Level of Evidence. Level III

BACKGROUND. Abnormal glenoid version positioning has been recognized as a cause of glenoid component failure caused by the rocking horse phenomenon. In contrast, the importance of the glenoid inclination has not been investigated. MATERIALS AND METHODS. The computed tomography scans of 152 healthy shoulders were evaluated. A virtual glenoid component was positioned in 2 different planes: the maximum circular plane (MCP) and the inferior circle plane (ICP). The MCP was defined by the best fitting circle of the most superior point of the glenoid and 2 points at the lower glenoid rim. The ICP was defined by the best fitting circle on the rim of the inferior quadrants. The inclination of both planes was measured as the intersection with the scapular plane. We defined the force vector of the rotator force couple and calculated the magnitude of the shear force vector on a virtual glenoid component in both planes during glenohumeral abduction. RESULTS. The inclination of the component positioned in the MCP averaged 95° (range, 84°–108°) and for the ICP averaged 111° (range, 94°–126°). A significant reduction in shear forces was calculated for the glenoid component in the ICP vs the MCP: 98% reduction in 60° of abduction to 49% reduction in 90° of abduction. CONCLUSION. Shear forces are significantly higher when the glenoid component is positioned in the MCP compared with the ICP, and this is more pronounced in early abduction. Positioning the glenoid component in the inferior circle might reduce the risk of a rocking horse phenomenon. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved

A commonly misunderstood principle in medical literature is statistical significance. Often, statistically non-significant or negative results are thought to be evidence for equivalence; mistakenly validating treatment modalities and putting patients at risk. This study examines the prevalence of misinterpretation of negative results of superiority trials in orthopaedic literature and outlines the need for a non-inferiority or equivalence research design. Four orthopaedic journals – Journal of Paediatric Orthopaedics A, Journal of Bone and Joint Surgery American Volume, Journal of Arthroplasty and Journal of Shoulder and Elbow Surgery – were hand searched to identify all randomised control trials (RCTs) published within the time periods 2002–2003, 2007–2008 and 2012–2013. The identified RCTs were read and classified by study methodology, results obtained, and interpretation of results. A total of 237 RCTs were identified. When analysing the primary outcomes, 117 (49.4%) studies yielded negative results and 120 (50.8%) yielded positive results. Out of the 237 articles, 231 (97.5%) used superiority methodology and 6 (2.5%) used non-inferiority or equivalence methodology. Of the 231 studies that used superiority methodology, 115 (49.8%) obtained negative results; and 45 (39.1%) of those misinterpreted the negative results for equivalence. While no statistical differences were seen, there was an upward trend in utilising non-inferiority and equivalence methodologies over time. Given the frequency of misinterpreted negative results, there is an evident need for a more appropriate research methodology that shows equivalence of treatment methods. A non-inferiority or equivalence study design can address orthopaedic clinical dilemmas more suitably when trying to show one treatment is no worse or is equal to another treatment. Regarding orthopaedic treatment modalities as equivalent when studies show negative statistical results can be detrimental to patients and their clinical outcomes. A non-inferiority methodology can be used to accurately depict no difference between treatment methods rather than attempting to show one treatment method as superior

Thirty years ago, rotator cuff surgery was exceedingly uncommon and shoulder arthroplasty almost unknown. Surgery for shoulder instability was largely empirical, non-anatomical and frequently unsuccessful. With the help of arthroscopy and MR scanning, a complex array of labral, ligament and tendon pathologies can now be recognised and treated, precisely and predictably. Anatomy-restoring arthroscopic techniques have largely replaced open stabilisation surgery. As life expectancy rises and citizens remain active into their seventh and eighth decades, the call for rotator cuff surgery has risen dramatically. Complex tendon transfers have expanded the indications for cuff surgery. Open repair has in part been supplanted by increasingly sophisticated arthroscopic techniques. The potential use of orthobiologics and stem cells promises further advances in the foreseeable future. Following the successful development of humeral hemiarthroplasty, and later of total shoulder replacement, surgical techniques and clinical indications for arthroplasty are now well refined. Predictable outcomes have been further enhanced by the present generation of ‘anatomic’ prostheses. More recently, the ‘rediscovery’ and improvement of semi-constrained (reverse) prostheses has transformed the previously dismal outlook for sufferers of cuff arthropathy and similar conditions. Many Australian Orthopaedic Association trainees undertake post-specialisation fellowships in shoulder surgery, both at home and abroad, and there is a steady flow of young overseas fellows through Australian shoulder units. The Shoulder and Elbow Society of Australia, founded in 1990 as a loose grouping of interested colleagues, now boasts over 70 active members. Australian surgeons and researchers are well represented in the prestigious Journal of Shoulder and Elbow Surgery and Australian shoulder surgery has come of age

In May 2012, in airports across the globe, seven orthopaedic surgeons bravely said goodbye to their loved ones, and slowly turned towards their respective aircraft. Filled with expectation and mild trepidation they stepped into the unknown… the ABC fellowship of 2012.