Focal articular surface replacement of knee lesions after failed cartilage repair using focal metallic implants: A series of 132 cases with 4-year follow-up.

Abstract

BACKGROUND\nFocal articular lesions of the knee can be treated using several different techniques with generally good results, but failures are difficult to manage. Focal articular surface replacement (FASR) using metal implants could be a promising technique that allows defect geometry matching, congruency restoration and defect propagation prevention.\n\n\nMETHODS\n132 patients were included who underwent FASR between January 2009 and December 2013. Three different implants were used: 1. HemiCAP®; 2. UniCAP® and 3. HemiCAP® PF Classic for trochlear lesions. Primary outcome parameter was knee function assessed by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score with a 4-year follow-up, secondary outcomes included survivorship and complications. Statistical analyses were performed using GraphPad Prism.\n\n\nRESULTS\nFor all 132 surgeries combined (102 HemiCAP®, 11 UniCAP® and 19 HemiCAP® PF Classic implants), WOMAC scores significantly improved from 6\xa0weeks onward until the end of the study (p\xa0<\xa00.001 for all time points). 4-year survival rate was 97.7%, and a re-operation rate of 12.1% was found. The HemiCAP® group revealed a slower WOMAC improvement in patients aged ≥40\xa0years, combined with a trend towards lower final WOMAC scores and a higher re-operation rate in patients with a BMI\xa0≥\xa025.\n\n\nCONCLUSIONS\nThis report shows good to excellent clinical results of FASR as a salvage procedure after failed cartilage repair, with a low re-operation rate and a high survival of 97.7% at 4-year follow-up. Although longer follow-up is required, this could be a valuable treatment option in these challenging cases, without limiting future options for surgical interventions when deemed necessary.