Introduction: Transplantation of autologous chondrocites offers promising results. A new technique is now gaining ground which uses a “scaffolding” of hyaluronic acid (Hyalograft C©, Fidia, Italy).

Materials and methods: Thirty-five patients have been treated with Hyalograft C© since 2000. 31 were operated on for a knee and 4 for an ankle. Clinical progression was documented both preoperatively and postoperatively by means of a clinical protocol (VAS-Scale, Lysholm, ICRS, IKDC; AOFAS, Cincinnati). Twenty-one patients with knee lesions (11 had particular circumscribed defects, 7 had complex lesions and/or related lesions, 3 patients were given this indication as a last resort in an effort to avoid the use of a prosthesis) and 4 with ankle lesions were followed up for over 6 months postop.

Results: Assessment by means of the VAS-Scale showed a reduction in pain. In addition, it was possible to show an improvement in function ranging from 51 points pre-op to 75 points post-op on the Lysholm Score. In patients with particular lesions an improvement of 57 to 97 points was achieved. All of the 3 patients where the indication was used as a last resort received a prosthesis. In ankles, the improvement ranged between 2,5 to 6.3 points on the modified Cincinnati-Score.

Conclusions: In the case of the classical indication for isolated femoral defects, the results obtained with Hyalograft C© show similar results to I.C.A. In complex lesions, results were considerably worse. Osteoarthritis has shown itself not to be an indication for this technique. On the other hand, the use of Hyalograft C© makes it possible to perform transplants with a smaller surgical incision as well as to fill defects without resorting to sutures.

Introduction and Objectives: Autologous chondrocyte suspension implantation (ACSI) has yielded good to excellent results in the treatment of cartilaginous defects of the knee. Thus far, studies on the ankle, analysing fewer subjects, offer promising results. Use of this technique in the ankle joint requires medial malleolar arthrotomy and osteotomy. Matrix-induced chondrocyte implantation (MICI) is a new technique involving the use of a hyaluronic acid-based matrix containing cultured chondrocytes.

Materials and Methods: Eight patients (4 male, 4 female) with an average age of 31 years (21–43) with defects in the talus were treated using ACSI and MICI. Average defect size was 1.9 cm. All patients had previously undergone surgery, and MRI showed Outerbridge grade IV osteochondral lesions on the talus. After clinical and radiological evaluation, arthroscopic surgery was performed to biopsy the articular cartilage of the talus. Later, a second surgery was performed with a mini-arthrotomy and debridement and cleaning of the defect. In ACSI, the defect is covered by suturing a periosteal graft to the cartilage, and the chondrocyte suspension is injected underneath. In MICI, a sheet of hyaluronic acid matrix with autologous chondrocytes of the same size as the defect is placed on the defect site and attached with fibrin glue. Patients were examined 28 months after implantation and evaluated using the Hannover Scoring system for the ankle.

Results: Follow-up results on the 8 patients verified an improvement of joint function and a reduction of pain in all cases. Hannover Scores increased in all patients. The osteotomy of the malleolus healed in all 8 cases. One patient was able to return to active competition in decathlon events.

Discussion and Conclusions: MICI requires a less complex surgical procedure and allows for a smaller incision. This technique therefore represents a broader application of tissue engineering in the treatment of cartilaginous defects of the ankle.