Mid- to long-term survivorship of the cemented, semiconstrained Discovery total elbow arthroplasty.

Background: The incidence of total elbow arthroplasty (TEA) is increasing, and an improved understanding of elbow kinematics and biomaterials has driven advances in implant design. In modern practice, cemented, semiconstrained devices are most frequently used. The Discovery TEA has demonstrated promising early results, although there are a paucity of follow-up studies and no dedicated mid- to 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 TEAs performed at a single non-design center. The minimum follow-up period was set at 5 years. Revision procedures and TEAs performed for acute trauma were excluded. The primary outcome was survivorship of the implant. The secondary outcomes included clinical, radiographic, and patient-reported outcomes.

Results: We identified 67 TEAs in 58 patients for inclusion at a mean of 98.5 ± 20.4 months from surgery. Four cases (6%) were lost to follow-up, and implant survival was censored accordingly. The implant was revised in 14 cases (20.9%). The Kaplan-Meier method showed an implant survivorship rate of 76.8% at 119 months. A significant difference in survival was found between dominant and nondominant elbows (P = .012, Breslow test), with elbow dominance conferring a 4.5-fold increased risk of revision (relative risk, 4.5; 95% confidence interval, 1.1-18.5). Pooled clinical outcomes (70.9% follow-up at minimum of 60 months and median of 77.8 months) were also determined.

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 with more established designs. We have also demonstrated differences in implant survivorship owing to hand dominance for the first time.