Stem retention and survival in revision of anatomical convertible shoulder arthroplasty to reverse arthroplasty: a Dutch registry study.

BACKGROUND: Convertible stem designs allow for stem retention during revision from anatomical to reverse shoulder arthroplasty. In some cases conversion is not possible for example due to excessive soft tissue tensioning. In these cases a total revision is necessary. The primary aim of this Dutch registry study was to evaluate the unforeseen stem reversion percentages in revision of convertible anatomical shoulder arthroplasty to reverse shoulder arthroplasty. METHODS: Shoulder arthroplasties (n = 2834) performed between 2014 and 2016 registered in the Dutch Arthroplasty Registry were selected. In 2016 94% of primary arthroplasties and 92% of revision arthroplasties were registered in the database. Arthroplasties were selected on convertibility. Mean follow-up was 2.4 years. We analysed the number of revisions for convertible and non-convertible designs. Cases with obligatory revisions as periprosthetic joint infections, stem loosening and periprosthetic fractures were excluded. Kaplan-Meier analysis was used to calculate humeral stem survival. Multivariate cox-regression analysis was used to determine risk factors for stem revision. RESULTS: The majority of procedures (respectively 90.9 and 72.1% for the convertible and non-convertible group) concerned a conversion to reverse shoulder arthroplasty (p = .02). In the convertible group, the stem was retained in 29 out of 40 patients (72.5%). Overall implant survival was 94.5% after a mean follow-up of 2.4 years. Hemiartroplasty, fracture as primary indication, previous shoulder surgery and lower age were risk factors for revision. CONCLUSIONS: Although convertible designs are gaining popularity due to their expected advantage in revision arthroplasty, surgeons should be aware that during a revision procedure in 27.5% of the patients an unforeseen stem revision is necessary.

Bone Microarchitecture and Distal Radius Fracture Pattern Complexity.

Distal radius fractures (DRFs) occur in various complexity patterns among patients differing in age, gender, and bone mineral density (BMD). Our aim was to investigate the association of patient characteristics, BMD, bone microarchitecture, and bone strength with the pattern complexity of DRFs. In this study, 251 patients aged 50-90 years with a radiologically confirmed DRF who attended the Fracture Liaison Service of VieCuri Medical Centre, the Netherlands, between November 2013 and June 2016 were included. In all patients fracture risk factors and underling metabolic disorders were evaluated and BMD measurement with vertebral fractures assessment by dual-energy X-ray absorptiometry was performed. Radiographs of all DRFs were reviewed by two independent investigators to assess fracture pattern complexity according to the AO/OTA classification in extra-articular (A), partially articular (B), and complete articular (C) fractures. For this study, patients with A and C fractures were compared. Seventy-one patients were additionally assessed by high-resolution peripheral quantitative computed tomography. Compared to group A, mean age, the proportion of males, and current smokers were higher in group C, but BMD and prevalent vertebral fractures were not different. In univariate analyses, age, male gender, trabecular area, volumetric BMD (vBMD), and stiffness were associated with type C fractures. In multivariate analyses, only male gender (odds ratio (OR) 8.48 95% confidence interval (CI) 1.75-41.18, p = 0.008]) and age (OR 1.11 [95% CI 1.03-1.19, p = 0.007]) were significantly associated with DRF pattern complexity. In conclusion, our data demonstrate that age and gender, but not body mass index, BMD, bone microarchitecture, or strength were associated with pattern complexity of DRFs.© 2019 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. J Orthop Res 37:1690-1697, 2019.