Radiocapitellar Contact Characteristics After Osteochondral Defect Repair Using a Novel Hybrid Reconstructive Procedure

Background: Many procedures to reconstruct osteochondral defects of the elbow radiocapitellar (RC) joint lack versatility or durability or do not directly address the subchondral bone structure and function. Purpose/Hypothesis: To biomechanically characterize the RC joint contact area, force, pressure, and peak pressure before and after reconstruction of osteochondral defects using a novel hybrid reconstructive procedure. It was hypothesized that the procedure would restore the contact characteristics to the intact condition. Study Design: Controlled laboratory study. Methods: A total of 10 cadaveric elbows (mean age 67 ± 2.7 years) were dissected to isolate the humerus and radial head. RC contact area, contact force, mean contact pressure, and peak contact pressure were measured with the elbow at 45° of flexion and neutral forearm rotation at compressive loads of 25, 50, and 75 N. Osteochondral defects 8 and 11 mm in diameter were created at the center of the capitellum; the defects were then reconstructed with a titanium fenestrated threaded implant, countersunk in the subchondral bone, with an acellular dermal matrix allograft sutured in place on top of the implant. Five conditions (intact, 8-mm defect, 8-mm repair, 11-mm defect, and 11-mm repair) were tested and results were compared using repeated-measures analysis of variance. Results: Both 8- and 11-mm defects significantly increased RC mean contact pressure at all compressive loads (P ≤ .008) and significantly increased peak contact pressure at compressive loads of 50 and 75 N (P < .002) compared with the intact condition. Repair of the 8-mm defect significantly decreased RC mean contact pressure at 25- and 50-N loads (P ≤ .009) and significantly decreased peak contact pressure at 50- and 75-N loads (P ≤ .035) compared with the defect condition. Repair of the 11-mm defect decreased mean contact pressure significantly at all compressive loads (P ≤ .001) and peak contact pressure at 50- and 75-N loads (P < .044) compared with the defect condition. Conclusion: RC joint contact pressure was restored to intact conditions while avoiding increased peak contact pressure or edge loading after repairing osteochondral defects related to osteochondrosis with a novel hybrid reconstruction technique. Clinical Relevance: This hybrid procedure that addresses the entire osteochondral unit may provide a new treatment option for osteochondral defects.