Does radial head implant fixation affect functional outcomes? A systematic review and meta-analysis

Abstract

Radial head arthroplasty is used in the treatment of nonreconstructible radial head fractures. Although traditional implants have been loosely fixed, smooth stemmed implants functioning more as spacers, modern designs have introduced press-fit, tapered implants that articulate at the capitellum with more rigidly maintained congruity. Cemented implants also use rigid initial fixation. This study was conducted to help determine which fixation method results in better functional outcomes: "fixed" or "unfixed." A systematic review and meta-analysis was used. We identified 63 articles via 3 databases. Ten non-English or articles with insufficient text were excluded, and 17 others did not contain sufficient data or follow-up. The remaining 36 articles were qualitatively and quantitatively reviewed. We identified 36 populations, with 878 unduplicated patients: 522 fixed and 356 unfixed. Respectively, mean follow-up in months was 46.2 and 37.4. Average Mayo Elbow Performance Scores were 85.9 and 88.2 (P = .08). Average Disabilities of the Arm, Shoulder and Hand scores were 17.1 and 18.7 (P = .47). Average final flexion/extension arcs were 119.1° and 115.8° (P = .08). Revision rates were 7.9% and 3.1%, and complication rates were 25.5% and 13.2%. Relative risks of revision and complications for the fixed cohort were 2.48 (P = .006) and 1.88 (P < 0.0001), respectively. Implant fixation type does not appear to affect functional outcomes of radial head arthroplasty. However, rigidly fixing the implant may increase the risks of revision and complications.