Ten-year clinical and radiographic outcomes after autologous chondrocyte implantation of femoral condyles.

PURPOSE: This prospective study assessed the 10-year clinical outcomes of periosteum autologous chondrocyte implantation (ACI) due to cartilage lesions of the femoral condyles. METHODS: Thirty-three of 45 patients (3 failures, 7 non-responders, 2 others) were available for clinical and radiographic evaluation at 2, 5, and 10 years. Patients were categorized into groups with focal cartilage lesions, osteochondritis dissecans (OCD), and cartilage lesions with simultaneous ACL reconstruction (ACL). Seven patients in the overall series required an arthroscopic re-intervention (3 ACI related, 4 ACI unrelated). RESULTS: Subjective knee scores and activity scores were significantly improved at 2 years toward their pre-operative levels and then remained stable up to 10 years; however, patients did not reach their pre-injury activity levels. Upon 10-year examination, using the IKDC knee examination form, there were 15 normal, 11 nearly normal, 5 abnormal, and 2 severely abnormal knees. Radiographic evidence of osteoarthritis was found in 45% of patients (5 focal lesions, 2 OCD, and 8 ACL). CONCLUSIONS: ACI provided safe and stable performance of operated knees over 10 years with a significant improvement toward pre-operative levels. Patients restrained from high-impact knee joint activities, post-surgery, and their knee radiographs demonstrated a high incidence of knee OA in trauma-related lesions. Optimal long-term performance is expected in localized, low-impact cartilage lesions of young patients. LEVEL OF EVIDENCE: Case series, Level IV.

Fibrin gel improved the spatial uniformity and phenotype of human chondrocytes seeded on collagen scaffolds.

A scaffold made of equine collagen type I based material has been assessed for its use in the preparation of tissue-engineered cartilage implants with human articular chondrocytes. Improvements of cell-seeding efficiency and specific gene expression were studied by combining solid scaffold with fibrin glue or human blood plasma. Following 3 weeks of static culture, mRNA expression levels of collagen type I, collagen type II, aggrecan and versican were analyzed by real-time quantitative PCR and compared to those in native cartilage and monolayer cell cultures. Constructs prepared with fibrin glue or plasma showed higher cell seeding efficiencies than those prepared without gel. Chondrocytes seeded directly onto a collagen scaffold appeared fibroblastic in shape while those encapsulated in fibrin gel were spherical. The presence of fibrin glue positively influences on mRNA levels of collagen type II and aggrecan, while blood plasma enhanced only the level of collagen type II expression. Levels of collagen type I and versican decreased in presence of fibrin glue. In orthopaedics, the combination of solid collagen fleece with fibrin gel for implant preparation is seen to be preferred over solid material or even cells in a suspension, since fibrin gel improves seeding capacity of the scaffold, supports equal distribution of cells and stimulates higher chondrogenic phenotype expression.

The outcome of autologous chondrocyte transplantation treatment of cartilage lesions in the knee.

Recent results of the clinical outcome of autologous chondrocyte transplantation (ACT) treatment in a group of 28 patients with focal femoral condyle cartilage lesions revealed a correlation trend with the quality of the in vitro cell culture matrix-protein synthesis. No impact of the patients' age and chondrocyte cryopreservation prior to implantation was observed. Further studies are needed to confirm the preliminary results.