Mid-long term survivorship of the cemented, semi-constrained

Abstract

Background: The incidence of total elbow arthroplasty (TEA) is increasing and improved understanding of elbow kinematics and biomaterials have driven advances in implant design. In modern practice, cemented semi-constrained devices are most frequently utilized. The Discovery TEA has demonstrated promising early results, though there is a paucity of follow-up studies and no dedicated mid-long term series. We therefore present the longest, most complete such study to date. Methods: A prospectively maintained local joint registry was interrogated to yield a consecutive series of Discovery TEA performed at a single non-design center. Minimum follow-up was set at 5 years. Revision procedures and TEA performed for acute trauma were excluded. Primary outcome was survivorship of the implant. Secondary outcomes included clinical, radiographic, and patient-reported outcomes. Results: Sixty-seven TEAs in 58 patients were identified for inclusion at a mean 98.5(+/-20.4) months from surgery. Four (6%) were lost to follow-up and implant survival censored accordingly. The implant was revised in 14 cases (20.9%). Implant survivorship was 76.8% at 119 months by the Kaplan-Meier method. There was a significant difference in survival between dominant and non-dominant elbows (Breslow test p=0.012), with elbow dominance conferring a 4.5-fold increased risk of revision (relative risk 4.5 [95% CI 1.1-18.5]). Pooled clinical outcomes (70.9% follow-up at minimum 60 and median 77.8 months) are also presented. Conclusions: We present the longest-term and most complete single-center follow-up study of the Discovery TEA to date. Further long-term survival studies are required to elucidate the performance of this implant compared to more established designs. We have also demonstrated differences in implant survivorship due to hand dominance for the first time.