Patient-reported outcome after stemmed versus stemless total shoulder arthroplasty for glenohumeral osteoarthritis: a patient-blinded randomized clinical trial.

BACKGROUND: Stemless shoulder arthroplasty systems with uncemented metaphyseal fixation have been used for glenohumeral osteoarthritis since 2004 (Hawi, et al. BMC Musculoskelet Disord 17:376, 2016). The stemless design has several theoretical advantages compared with the stemmed shoulder arthroplasty systems: restoring patients' anatomy; preserving humeral bone stock; and few complications in component removal if the need for a revision arthroplasty arises. The purpose of the study is to compare the short-term, patient-reported outcome of stemless and stemmed total shoulder arthroplasty (TSA). MATERIALS AND METHODS: A randomized clinical trial will be conducted. Eighty patients with clinical and radiological signs of primary or post-traumatic glenohumeral osteoarthritis, computed tomography (CT) scan-verified adequate glenoid bone stock, and no total rupture of rotator cuff tendons verified by a magnetic resonance imaging (MRI) scan will be randomly allocated to a stemless or stemmed TSA. The primary outcome will be the Western Ontario Osteoarthritis Shoulder (WOOS) score at 12 months. Secondary outcomes are the WOOS score at three months and the Oxford Shoulder Score (OSS) and EQ-5D at 3 and 12 months. All complications, including glenoid and humeral component loosening, instability, rotator cuff tear, intraoperative and postoperative periprosthetic fracture, nerve injury, infection, deltoid injury, and symptomatic deep venous thrombosis, will be reported. DISCUSSION: Findings will provide patients with better information about the potential benefits and harms of stemless and stemmed TSA and will assist shoulder surgeons and patients in decision-making. TRIAL REGISTRATION: Clinicaltrials.gov, NCT03877315 . Registered on 13 March 2019.

Low inter-observer agreement among experienced shoulder surgeons assessing overstuffing of glenohumeral resurfacing hemiarthroplasty based on plain radiographs.

BACKGROUND: In a clinical setting, a visual evaluation of post-implant radiographs is often used to assess the restoration of glenohumeral joint anatomy after resurfacing hemiarthroplasty and is a part of the decision-making process, in combination with other parameters, when evaluating patients with inferior clinical results. However, the reliability of this method of visual evaluation has not been reported. The aim of this study was to investigate the inter- and intra-observer agreement among experienced shoulder surgeons assessing overstuffing, implant positioning, and size following resurfacing hemiarthroplasty using plain standardized radiographs. METHODS: Six experienced shoulder surgeons independently classified implant inclination, size of the implant and if the joint seemed overstuffed, in 219 cases of post-implant radiographs. All cases were classified twice 3 weeks apart. Only radiographs with an anterior-posterior projection with a freely visible joint space were used. Non-weighted Cohen's kappa values were calculated for each coder pair and the mean used as an estimate of the overall inter-observer agreement. RESULTS: The overall inter-observer agreement for implant size (kappa, 0.48 and 0.41) and inclination angle was moderate in both rounds (kappa, 0.46 and 0.44), but only a fair agreement was found concerning the evaluation for stuffing of the joint (kappa, 0.24 and 0.28). Intra-observer agreement for implant size and stuffing ranged from fair to substantial while the agreement for inclination was moderate to substantial. CONCLUSIONS: Our results indicate that a visual evaluation of plain radiographs may be inadequate to evaluate overstuffing, implant positioning, and size following resurfacing hemiarthroplasty using plain standardized radiographs. Future studies may contribute to elucidate whether reliability increases if consensus on clear definitions and standardized methods of evaluation is made.