HemiCAP Knee Implants: Mid- to Long-Term Results

Abstract

Purpose The aim of the study was to investigate the long-term outcomes of the Focal Femoral Condyle Resurfacing Prosthesis (HemiCAP) using clinical and radiographic assessments, and to evaluate the revision and survival rates. Methods Clinical evaluation was performed in those not revised and was able to participate. This was a prospective single-center cohort study of HemiCAP patients with 7 to 10 years of clinical and radiographic follow-up. The clinical examination included the Knee Society Score (KSS) and visual analogue scale (VAS) score. The radiographic examination included the Kellgren-Lawrence (KL) grade. Survival was estimated by Kaplan-Meier survival analysis, and potential risk factors for revision was evaluated by a regression analysis. Results Of the 62 patients with 64 HemiCAP prostheses, 37 were HemiCAP condyle, 11 HemiCAP PF, and 16 HemiCAP Wave; 27 (42%) were revised—HemiCAP condyle 17 (42%), HemiCAP PF 4 (36%), HemiCAP Wave 6 (37%), and 1 died. Examinations were performed on 31 patients (86%). When compared with the preoperative data, there were significant increases in the KSS objective (mean = 51.5, standard deviation [SD] = 5.9 vs. mean =94.2, SD = 5.0) and function (mean = 51.0, SD = 6.2 vs. mean = 93.7, SD = 4.8) scores, a decrease in the VAS score (mean = 7.1, SD = 0.7 vs. mean = 2.7, SD = 1.7) and a decrease in the KL lateral score (mean = 1.1, SD = 0.3 vs. mean = 0.6, SD = 0.6). The mean follow-up was 7.3 years (SD 1.4) with minimum 4.2 years and maximum 10.2 years. No failures occurred in the series beyond 5 years. Conclusions As hypothesized, we found good clinical and radiographic outcomes, and for those patients who did not require revisions, there were long-term improvements in disability and function. This suggests that patient selection is a key element to successfully applying these devices in clinical practice.

A longterm prospective follow-up study of resurfacing miniprosthesis suitable for patients above sixtyfive years with localized cartilage lesions or early osteoarthritis in the knee

“…This suggests that if symptomatic degenerative cartilage lesions are of limited size rather than an element of generalized OA, then resurfacing implant treatment can provide long-term improvement. The results of 70% not revised to knee arthroplasty after mean 9 years, indicate that resurfacing implants may limit the need for a UKA or TKA in elderly patients (> 65 years old) with symptomatic cartilage lesions or early degenerative knee pathologies [8,11,[15][16][17][18]. Thus far, the present study is the only and largest long-term case series, with 23 femoral resurfacing mini prostheses in elderly knee-patients with clinical and radiographic follow-up up to 11 years, including revision and survival rates.…”

Eighty Percent Survival of Resurfacing Implants in the Knee After 10 Years: A Nationwide Cohort Study on 379 Procedures from the Danish Knee Arthroplasty Registry

“…Laursen et al . 22 have published a series of studies on HemiCap and UniCap. The authors followed 62 patients with 64 HemiCap prosthesis for 7 to 10 years and found a revision rate of 42%.…”

“…The authors followed 62 patients with 64 HemiCap prosthesis for 7 to 10 years and found a revision rate of 42%. 22 Studying the HemiCap Wave for patellofemoral defects, the authors found a revision rate of 28% after 6 years in 18 patients 22 and in 64 patients treated with UniCap (designed for larger defects), the authors found a revision rate of 56%. 23 Laursen et al .…”

“…23 Laursen et al . 22 reported that the subgroup of patients who did not require early revision had lasting clinical improvements, and no progression of osteoarthritis was seen, while patients suffering from osteoarthritis and patients who did hard, manual labor had a significantly higher risk of revision. This indicates that patient selection is of great importance.…”

“…In addition, some studies report a relatively high revision rate. 22-24 Therefore, our objective was to investigate the 10-year survival of resurfacing implants from a nationwide cohort registered in the Danish Knee Arthroplasty Registry.…”