Focal articular surface replacement as primary treatment for focal chondral defects of the femoral condyles: A series of 157 cases.

Abstract

Focal chondral defects (FCDs) of the femoral condyle are common. Treatment has heretofore primarily consisted of non-surgical and biological treatments. Focal articular surface replacement (FASR) is an emerging technique utilizing small implants to essentially fill the FCD. Here we report functional outcome and re-operation rates following FASR as a primary treatment for FCDs of the femoral condyles. Retrospective analysis of a prospectively collected database including 327 FASR procedures was performed to identify patients who underwent FASR of the femoral condyle with a modular cementless metallic implant (HemiCAP^TM) as a primary procedure. Knee Injury and Osteoarthritis Outcome Score (KOOS), Oxford Knee Score (OKS), SF-36 Health Status Survey (SF-36) and Visual Analog Scale (VAS) were collected before and 6 weeks, 6 months, and 4 years after surgery. Implant revision and re-operation rate were recorded. 157 patients were included with a mean follow-up of 9.4 ± 1.3 years (range 7.0 to 11.4 years). The average age was 40.2 ± 5.3 years, 85% involved the medial condyle, and the average defect size was 3.6 ± 0.5 cm². Primary FASR resulted in functional improvement on the KOOS (+52%), OKS (+69%) and SF-36 (+50%) scores and a reduction in VAS scores (-70%) at 4-year follow-up. Revision rate was 0.64% and the re-operation rate was 11%. This retrospective case-series supports primary FASR with HemiCAP^TM implants as an alternative to biological procedures to treat medium-sized FCDs (2.5-4 cm²) of the femoral condyle, although long-term follow-up is necessary to determine if the clinical outcome and low revision rate can be maintained.