The partial femoral condyle focal resurfacing (HemiCAP-UniCAP) for treatment of full-thickness cartilage defects, systematic review and meta-analysis

Abstract

Knee osteochondral defects are a common problem among people, especially young and active patients. So effective joint preserving surgeries is essential to prevent or even delay the onset of osteoarthritis for these group of patients. This study aims to critically appraise and evaluate the evidence for the results and effectiveness of femoral condyle resurfacing (HemiCAP/ UniCAP) in treatment of patients with focal femoral condyle cartilage defect. Using the search terms : HemiCAP, UniCAP, Episurf, focal, femoral, condyle, inlay and resur-facing, we reviewed the PubMed and EMBASE and the Cochrane Database of Systematic Reviews (CDSR) to find any articles published up to March 2020. The short term follow-up of the HemiCAP shows (6.74 %) revision rate. However, 29.13 % loss of follow up let us consider these results with caution especially if the revision rate progressively increased with time to 19.3 % in 5-7 years with no enough evidence for the long term results except the data from the Australian Joint Registry 2018, where the cumulative revision rate was 40.6 % (33.5, 48.4) at ten years. The UniCAP that used for defect more than 4 cm 2 has a high revision rate (53.66 %) which is considered unacceptable revision rate in com-parison to another similar prosthesis such as Uni-Knee Arthroplasty (UKA). The evidence from published studies and our meta- analysis suggests that partial resurfacing of the femoral condyle (HemiCAP) doesn’t support its usage as a tool to treat the focal cartilage defect in middle- aged patients. The UniCAP as femoral condyle resurfacing has very high revision rate at 5-7 years (53.66 %) which make us recommend against its usage.

High degree of consensus amongst an expert panel regarding focal resurfacing of chondral and osteochondral lesions of the femur with mini-implants

“…A good subjective outcome was obtained in both studies with a low revision rate [4, 17]—one patient was revised to unicompartmental knee arthroplasty (UKA), and one was revised to bone grafting and a membrane [17]. The majority of the related literature focus on the HemiCAP ® and UniCAP ® implants, including four systematic reviews [5, 14, 15, 21] and data from two large registries [2, 10]. All these studies represent evidence level 4, whilst the reported revision rate ranges widely.…”

Fostering Excellence in Knee Arthroplasty: Developing Optimal Patient Care Pathways and Inspiring Knowledge Transfer of Advanced Surgical Techniques

“…31 Difficulties in achieving the required precision when implanting these devices led to high failure rates in the first postoperative years, 32 with a cumulative revision rate of over 50% after seven years in the Australian Joint Registry. 33 With the advent of patient-specific instrumentation based on preoperative 3D planning, patient-specific implants for focal cartilage lesions have been introduced (Episurf, EPISEALER, 4 Medical s.r.l., Cinisello Balsamo, Italy), the first clinical results of which appear promising with a revision rate of 2.5% after 2 years. 34,35 Even isolated replacements of the trochlea have been introduced.…”