Background

and study aims
Focal femoral resurfacing implants have been developed as a treatment option for patients with full-thickness cartilage lesions. They are typically offered for middle-aged patients who are deemed too young for conventional arthroplasty, but also not suitable for biological procedures. This study aims to critically appraise and evaluate the evidence pertaining to these devices.

Material And Methods

Using the search terms: HemiCAP, UniCAP, Episurf, focal, femoral, condyle, inlay and resurfacing, we reviewed the PubMed, EMBASE and the Cochrane Database of Systematic Reviews to find any articles published up to March 2020.

Results

14 papers met the inclusion criteria, reporting on four different prosthetic devices. The HemiCAP, BioPoly, and Episealer are designed to be used in lesions <3.1cm2; whilst the UniCAP can be used in larger lesions and in areas of localised OA. The mean conversion rate for the implants designed to treat smaller lesions was 6.2% at 2 years, and 18.8% at 5-7 year follow-up. For the UniCAP device, the survivorship is reported to be approximately 40% at 9 years. We observed favourable short-term functional scores however there is a lack of robust medium and long-term data.

Conclusion

Our study suggests that survivorships results with these implants is still unpredictable. If there is a potential subgroup of patients who benefit from focal femoral resurfacing, their selection criteria needs to be refined. This would suggest that as present these implants should be used cautiously, and only in well-designed clinical trials.