Clinical evaluation of a resurfacing device implant for femoral osteochondral defects greater than 1 cm2 with a minimal follow-up of 4 years: a prospective cohort study

Abstract

Purpose: Osteochondral defects have a limited capacity to heal and can evolve to an early osteoarthritis. A surgical possibility is the replacement of the affected cartilaginous area with a resurfacing device BioPoly™ RS Partial Resurfacing Knee Implant. The aim of this study was to report the clinical and survival outcomes of the BioPoly™ after a minimum follow-up of 4 years.

Methods: This study included all patients who had a BioPoly™ for femoral osteochondral defects greater than 1 cm² and at least ICRS grade 2. The main outcome was to observe the KOOS and the Tegner activity score were used to assess outcomes preoperatively and at the last follow-up. The secondary outcomes were the VAS for pain, the complications rate post-surgery and survival rate of BioPoly™ at the last FU.

Results: Eighteen patients with 44.4% (8/18) of women were included with a mean age of 46.6 years (11.4), a mean body mass index (BMI) of 21.5 (kg/m²) (2.3). The mean follow-up was 6.3 years (1.3). We found a significant difference comparing pre-operative KOOS score and at last follow-up [respectively, 66.56(14.37) vs 84.17(7.656), p < 0.01]. At last follow-up, the Tegner score was different [respectively, 3.05(1.3) vs 3.6(1.3), p < 0.01]. At 5 years, the survival rate was of 94.7%.

Conclusions: BioPoly™ is a real alternative for femoral osteochondral defects greater than 1 cm² and at least ICRS grade 2. It will be interesting to compare this implant to mosaicplasty technic and/or microfracture at 5 years postoperatively regarding clinical outcomes and survival rate.

Level of evidence: Therapeutic level III. Prospective cohort study.

Keywords: Knee injury; Osteochondral defect; Prosthetic button; Sport medicine.