Satisfactory survivorship and clinical outcomes up to 10 years after the implantation of a novel personalized metal implant for the treatment of osteochondral lesions of the knee.

Abstract

Treating knee cartilage lesions in middle-aged patients is challenging, particularly when lesions involve the subchondral bone. Personalized focal arthroplasty implants offer a solution when biological repair is no longer optimal or has failed. These small cobalt-chrome implants, designed using patient-specific magnetic resonance imaging (MRI) data, anatomically restore the damaged area with a custom-fit implant. This observational, single centre, clinical study reports mid-to-long-term outcomes (2-10 years) of a novel personalized focal arthroplasty implant. Thirty-four patients (13 women, 21 men) with a mean age of 49.7 years (±6.9; 24-63) underwent implantation of a small metal implant and were followed for at least two years (mean follow-up 49.4 months, range 24-120 months). A single plug was used in 33 patients (23 medial femoral condyle [MFC], 4 lateral femoral condyle [LFC], 6 trochlea), while one received two plugs. Two patients underwent concomitant high tibial osteotomy. In 61.7 ​% of cases, implantation was a revision after failed biological cartilage repair. Clinical scores (VAS, KOOS, IKDC) were recorded at baseline, two years, and final follow-up. Statistical analysis was performed using paired Student's t-tests (p ​< ​0.05). Implant survival was assessed via Kaplan-Meier analysis, with failure defined as implant removal. Statistically significant improvements in all clinical scores (VAS, KOOS, IKDC) were observed between baseline and two years and then remained stable. VAS decreased from 6.6 (±2.1) to 3.1 (±3) at two years (p ​< ​0.001) and then to 2.9 (±3.2) at final follow-up. KOOS Symptoms increased from 57.1 (±21.3) to 77.4 (±20.8) at two years (p ​< ​0.001) and to 75.1 (±22.2) at final follow up, while IKDC improved from 34.9 (±13.9) to 58.2 (±22.7) at two years (p ​< ​0.001) and to 59.5 (±25.7) at final follow up. Three failures occurred, requiring revision to total or unicompartmental knee replacement. Kaplan-Meier survival rate was 91.2 ​%. Middle aged patients with osteochondral lesions of the knee benefit from good clinical outcomes, high survival rates, and an excellent safety profile up to 10 years after the implantation of a novel personalized small-metal implant. Level II. Prospective cohort study.