Participation in a physical therapy program is considered one of the greatest predictors for successful conservative management of common shoulder disorders, however, adherence to standard exercise protocols is often poor (around 50%) and typically worse for unsupervised home exercise programs. Currently, there are limited tools available for objective measurement of adherence and performance of shoulder rehabilitation in the home setting. The goal of this study was to develop and evaluate the potential for performing home shoulder physiotherapy monitoring using a commercial smartwatch. We hypothesize that shoulder physiotherapy exercises can be classified by analyzing the temporal sequence of inertial sensor outputs from a smartwatch worn on the extremity performing the exercise. Twenty healthy adult subjects with no prior shoulder disorders performed seven exercises from a standard evidence-based rotator cuff physiotherapy protocol: pendulum, abduction, forward elevation, internal/external rotation and trapezius extension with a resistance band, and a weighted bent-over row. Each participant performed 20 repetitions of each exercise bilaterally under the supervision of an orthopaedic surgeon, while 6-axis inertial sensor data was collected at 50 Hz from an Apple Watch. Using the scikit-learn and keras platforms, four supervised learning algorithms were trained to classify the exercises: k-nearest neighbour (k-NN), random forest (RF), support vector machine classifier (SVC), and a deep convolutional recurrent neural network (CRNN). Algorithm performance was evaluated using 5-fold cross-validation stratified first temporally and then by subject. Categorical classification accuracy was above 94% for all algorithms on the temporally stratified cross validation, with the best performance achieved by the CRNN algorithm (99.4± 0.2%). The subject stratified cross validation, which evaluated classifier performance on unseen subjects, yielded lower accuracies scores again with CRNN performing best (88.9 ± 1.6%). This proof-of concept study demonstrates the feasibility of a smartwatch device and machine learning approach to more easily monitor and assess the at-home adherence of shoulder physiotherapy exercise protocols. Future work will focus on translation of this technology to the clinical setting and evaluating exercise classification in shoulder disorder populations

Reverse shoulder arthroplasty is becoming a frequent treatment of choice for patients with shoulder disorders. Complication rates after reverse shoulder arthroplasty may be three-fold that of conventional total shoulder arthroplasty especially in high risk patient populations and diagnoses like revision arthroplasty, fracture sequelae, and severe glenoid bone loss. Complications include component malposition, stiffness, neurological injury, infection, dislocation or instability, acromial or scapular spine fractures, scapular notching, and loosening of implants. Recognition of preoperative risk factors and appropriate 3D planning are essential in optimizing patient outcome and intraoperative success. Failure of reverse shoulder arthroplasty is a significant challenge requiring appropriate diagnosis of the failure mode. The most common neurological injuries involve the brachial plexus and the axillary nerve due to traction, manipulation of the arm, aberrant retractor placement, or relative lengthening of the arm. Intraoperative fractures are relatively uncommon but include the greater tuberosity, acromion, and glenoid. Tuberosity fracture can be repaired intraoperatively with suture techniques, glenoid fractures may be insignificant rim fractures or jeopardise baseplate fixation and require abandoning RSA until glenoid fracture ORIF heals and then a second stage RSA. Periprosthetic infection after RSA ranges from 1 to 10% and may be higher in revision cases and frequently is Propionibacterium acnes and Staphylococcus epidermidis. Dislocation was one of the most common complications after RSA approximately 5% but with increased surgeon experience and prosthetic design, dislocation rates are approaching 1–2%. An anterosuperior deltoid splitting approach has been associated with increased stability as well as subscapularis repair after RSA. Scapular notching is the most common complication after RSA. Notching may be caused by direct mechanical impingement of the humerosocket polyethylene on the scapular neck and from osteolysis from polyethylene wear. Sirveaux classified scapular notching based on the defect size as it erodes behind the baseplate towards the central post. Acromial fractures are infrequent but more common is severely eroded acromions from CTA, with osteoporosis, with excessive lengthening, and with superior baseplate screws that penetrate the scapular spine and create a stress riser. Nonoperative care is the mainstay of acromial and scapular spine fractures. Recognizing preoperative risk factors and understanding component positioning and design is essential to maximizing successful outcomes

BACKGROUND:. Few studies have evaluated at a medium-term follow-up the use of semiconstrained reverse shoulder arthroplasty (RSA) for primary glenohumeral osteoarthritis, massive rotator cuff tear, or cuff tear arthropathy excluding any other shoulder disease. Moreover, data on patients' quality of life after this surgery are lacking. METHODS:. In this prospective cohort study, 80 patients were evaluated after an RSA for either primary osteoarthritis, massive rotator cuff tear, or cuff tear arthropathy with the Constant-Murley score (CMS), ROM, and Short Form Health Survey (SF-36). A radiologic assessment was performed pre- and postoperatively. RESULTS:. At a mean 5-year follow-up, the cumulative survival rate was 97.3% and significant improvements in the CMS and ROM were observed when compared with the baseline values. The CMS was 93.2% of the sex- and age-matched normal values. The postoperative SF-36 scores showed no significant differences compared with normative data. Younger patients and subjects with worse preoperative conditions achieved the greatest benefit after RSA. A 70% scapular notching rate was noted and the length of follow-up was found to be associated with the severity of scapular notching. CONCLUSIONS:. This study introduces new predictors for surgical outcomes, and it shows that patients who had undergone RSA a mean of 5 years earlier exhibit similar functionality and health-related quality of life with respect to healthy controls

Purpose. Total shoulder arthroplasty (TSA) has become a successful treatment option for degenerative shoulder disease. With the increasing incidence in primary TSA procedures during the last decades, strategies to improve implant longevity become more relevant. Implant failure is mainly associated with mechanical or biological causes. Chronic inflammation as a response to wear particle exposure is regarded as a main biological mechanism leading to implant failure. Metal ions released by fretting and corrosion at modular taper connections of orthopedic implants can cause cell-mediated hypersensitivity reactions and might lead to aseptic loosening. Modularity is also commonly used in total shoulder replacement. However, little is known about metal ion exposure in patients following TSA. The objective of this study was to determine in-vivo blood metal ion levels in patients after TSA and to compare blood metal ion levels to control subjects without metal implants. Methods. A total of 19 patients with anatomical total shoulder prosthesis (TSA group) and 20 patients with reverse total shoulder prosthesis (RSA group) who underwent unilateral total shoulder replacement at our hospital between March 2011 and December 2014 with no other metal implant or history of environmental metal ion exposure were recruited for analysis of blood metal ion concentrations of cobalt (Co), chromium (Cr) and titanium (Ti) at a mean follow-up period of 2.3 years (0.7–4.3). For comparison of metal ion concentrations blood samples were obtained in a healthy control group of 23 subjects without metal implants. Ethical approval and informed consent of each patient were obtained for this study. Results. Median cobalt ion levels were 0.14µg/l (range 0.03–0.48) in the TSA group, 0.18 µg/l (0.10–0.66) in the RSA group and 0.11µg/l (0.03–0.19) in the control goup. Median chromium ion levels were 0.34µg/l (0.09–1.26) in the TSA group, 0.48µg/l (0.17–2.41) in the RSA group and 0.14µg/l (0.04–0.99) in the control goup. Median titanium ion levels were 0.86µg/l (0.10–1.64) in the TSA group, 1.31µg/l (0.75–4.52) in the RSA group and 0.62µg/l (0.32–2.14) in the control goup. There was a statistically significant difference in chromium and titanium ion concentrations between both study groups and the control group (see figure 1–3). Conclusion. Patients with unilateral total shoulder replacement demonstrated elevated blood metal ion concentrations. Median blood metal ion levels were higher in the RSA group compared to the TSA group, which could be attributable to the modularity of the reverse total shoulder system. However, overall metal ion levels were relatively low compared to those seen in patients with metal-on-metal total hip replacements. The role of local metal ion exposure in the development of aseptic loosening or hypersensitivity reactions associated with total shoulder arthroplasty should be further investigated. For figures/tables, please contact authors directly.

Reverse shoulder arthroplasty (RSA) is increasingly performed recently. The patients seeking internet as a source of information may get misleading and a false sense of expectation. This study aimed at analysing patient information on internet and establish list of available quality websites to safely recommend to the patients. The study analysed 310 websites from 10 top search engines exploring the quality of patient information using an assessment tool. Search engines used were metasearch (Metacrawlers and Mamma), general search (Google, Altavista, Yahoo, MSN, AOL, Lycos) and health search engines (Medhunt and Excite Health). The study was undertaken by two independent researcher over a four-week period in November 2011. Each Website was evaluated according to RSA-specific content using a point value system with shoulder disease and surgery specific key words on an ordinal scale. Adequacy of the content was analysed in regard with description of diagnosis, procedure, alternate options, postoperative protocol, complications and prognosis. Excluding the repetitions 104 websites were analysed for accessibility, relevance, authenticity, adequacy of patient information and accountability. The median time since update was 12 months. More than 90% of the websites were found to be of poor quality. Only 25% sites targeted mainly people with shoulder problems. 8% of websites were from non profit organisations. Most of these websites were promoting either their service 80 (76%) or some product 12 (11%). The strength of association between two reviewers was very high (r = 0.899). Intra-rater reliability was significant (r = 0.955) with p level < 0.01. The reading level of most of websites were too high for average consumers. There is need for government organizations and professional societies to regulate the information provided by Internet. Until long-term data are available, patients should be warned when using the Internet as a source for health care information