Actifit synthetic meniscal substitute: experience with 18 patients in Brest, France.

BACKGROUND: The management of post-meniscectomy pain is poorly standardised. Allogeneic transplantation may be appropriate in some patients after total meniscectomy. After partial meniscectomy, the synthetic meniscal substitute Actifit may constitute a valid option if the knee is stable or stabilised and aligned or re-aligned. The interconnected pore structure of Actifit promotes tissue regeneration from the meniscal wall. Arthroscopy is used to position the implant, which is then sutured to the remaining native meniscus using horizontal stitches and to the meniscal wall using vertical stitches. However, a burdensome programme of rigorous rehabilitation is required after Actifit implantation. HYPOTHESIS: We hypothesised that implantation of a meniscal substitute effectively alleviated pain without adversely affecting the knee. OBJECTIVES: To assess the intra-articular behaviour of Actifit and the outcomes of Actifit implantation in a prospective case-series of patients monitored using arthroscopy, pathology, and imaging studies, as well as the Lysholm score to assess clinical benefits on daily activities. MATERIALS AND METHODS: Between October 2009 and April 2012, 18 patients underwent Actifit implantation at the military hospital in Brest, France. All procedures were performed by the same surgeon, who had extensive experience with meniscal suturing. There were 13 males and 5 females aged 20 to 46 years. The medial meniscus was involved in 13 patients and the lateral meniscus in 5 patients. Actifit implantation was used alone in 6 patients and in combination with anterior cruciate ligament reconstruction and/or realignment osteotomy in 12 patients. All patients were followed-up for at least 2 years. RESULTS: The mean Lysholm score after 1 year was 92%, indicating excellent outcomes. Magnetic resonance imaging showed no damage to the implant or degeneration of the neighbouring cartilage. Histological examination of meniscal substitute biopsies taken 1 year after implantation showed polymer ingrowth by normal chondrocytes and fibrochondrocytes. The clinical and radiographic outcomes compared favourably with those seen after isolated procedures on bone or ligaments. DISCUSSION: Actifit has no deleterious effects on patients. The implant induces and promotes meniscal regeneration. Actifit constitutes a major addition to our therapeutic armamentarium. We provide convincing evidence that meniscal reconstruction can be highly beneficial in decreasing the risk of progression to knee osteoarthritis. LEVEL OF EVIDENCE: IV.