Reconstruction of osteochondral lesions of the talus with autologous spongiosa grafts and autologous matrix-induced chondrogenesis

Abstract

Background: Osteochondral lesions (OCLs) of the talus are a common entity in sports orthopaedics. There are several operative techniques with a good outcome on follow-up examinations. However, limitations such as sacrificing healthy cartilage (osteochondral autograft transfer system [OATS], mosaicplasty), multiple-stage operative procedures (matrix-induced autologous chondrocyte transplantation [MACI], autologous chondrocyte implantation [ACI]), high costs (ACI, allograft), and limited availability (allograft) do remain and reflect potential drawbacks of the currently used techniques.

Purpose: To describe a novel operative technique for the treatment of OCLs of the talus in the form of an economically efficient, 1-step procedure combining OCL debridement, spongiosaplasty, and sealing of the OCL area with a collagen matrix.

Study design: Case series; Level of evidence, 4.

Methods: Twenty-six patients underwent surgery receiving a modified autologous matrix-induced chondrogenesis (AMIC)-aided repair of OCLs of the talus consisting of debridement, autologous grafting, and sealing of the defect with a collagen scaffold. Ligament repair was performed in 17 of 26 cases. A corrective calcaneal osteotomy was performed in 16 of 26 cases. Clinical and radiological assessment was performed before and a minimum of 24 months after surgery (mean, 31 months; range, 24-54 months). Clinical examination included the American Orthopaedic Foot and Ankle Society (AOFAS) ankle score and the visual analog scale (VAS) for pain. Radiological imaging included single-photon emission computed tomography-computed tomography (SPECT-CT) and magnetic resonance imaging (MRI). The magnetic resonance observation of cartilage repair tissue (MOCART) score was applied, and sport activity was documented.

Results: The AOFAS ankle score improved significantly from a mean of 60 points preoperatively (range, 17-79 points) to 89 points (range, 61-100 points) postoperatively (P < .01). The preoperative pain score averaged 5 (range, 2-8), improving to an average of 1.6 (range, 0-7) postoperatively (P < .01). The MOCART score for cartilage repair tissue on postoperative MRI averaged 62 points (range, 20-95 points). Complete filling of the defect at the level of the surrounding cartilage was found in 35%, and complete filling with a hypertrophic cartilage layer was found in 50% of the patients. Normal signal intensity of the repair tissue compared with the adjacent native cartilage was seen in 15%, with nearly normal activity in 69%. Nineteen patients (73%) participated in sports before the onset of symptoms compared with 3 (12%) at the time of surgery. The number increased to 16 patients (62%) at postoperative follow-up.

Conclusion: The modified AMIC procedure is safe for the treatment of OCLs in the ankle with overall good clinical and MRI results.