Treatment of deep articular talus lesions by matrix associated autologous chondrocyte implantation--results at five years

Abstract

Purpose: Treatment of focal full-thickness chondral or osteochondral defects of the talus remains a challenge. The aim of this study was to evaluate the postoperative success and the long-term efficacy of matrix associated autologous chondrocyte implantation in these defects.

Methods: Matrix associated autologous chondrocyte implantation (MACI) was applied in 22 consecutive patients (mean age 23.9 years) with full-thickness chondral or osteochondral lesions of the talus. The average defect-size was 1.94 cm² (range 1-6). In case of osteochondritis dissecans (n = 13) an autologous bone graft was performed simultaneously. Follow-ups were routinely scheduled up to 63.5 (±7.4) months, consisting of clinical evaluation and magnetic resonance imaging.

Results: The AOFAS score improved significantly from 70.1 to 87.9/92.6/93.5/95.0/95.5 and 95.3 points at three, six, 12, 24, 36 and 63.5 months, respectively. On a visual analogue scale, pain intensity decreased from 5.7 (±2.6) to 0.9 (±0.8) while subjective function increased from 5.3 (±2.3) to 8.9 (±0.9) at final follow-up (each p < 0.001). The Tegner score rose significantly from 2.4 (±1.2) to 4.7 (±0.6). The MOCART score improved from 62.6 (±19.4) at three months to 83.8 (±9.4) at final follow-up. No significant differences were found between lesions caused by osteochondritis dissecans or trauma and between first- or second-line treatments. For all scores, the most benefit was seen within the first 12 months with stable results afterwards. No major complications were noted.

Conclusions: Matrix associated autologous chondrocyte implantation is capable of significant and stable long-term improvement of pain and functional impairment caused by focal full-thickness chondral and osteochondral talus lesions.

Fig. 1

MACI implantation into a typical lateral OCL of the left talus (defect-size 3.6 cm²). The defect was exposed and the unstable fragment removed (a). A vital subchondral bone stock was prepared (b). The defect was filled with autologous cancellous bone graft from the distal anterior tibia (c). The cell loaded scaffold (MACI) was applied and sealed with fibrin glue (d)

Fig. 2

AOFAS score results

Fig. 3

MOCART score results

Fig. 4

Representative preoperative coronal and sagittal MRI (T2-weighted) of an OD on the medial talus ICRS grade III (2.4 cm², AOFAS score 72 points) (a, b). At 63 months, the defect is completely filled by smooth repair tissue. Persistent irregularities of the subchondral bone, small cyst after cancellous bone grafting (MOCART score 70 points, AOFAS score 90 points) (c, d)

Fig. 5

Case no. 1: The arthroscopic view shows the former defect filled completely by a smooth, well integrated but softer regenerative tissue (arrow heads) (a). A full core biopsy detects regenerative tissue tightly bonded with native hyaline cartilage on the right (arrow heads). Partly uneven surface. Numerous, viable cells with chondrocytic phenotype in the superficial zone. The junctional zone shows an increased bone remodelling after cancellous bone grafting. No tide mark is detectable (hematoxylin-eosin, magnification ×5) (b). High content of glycosaminoglycans (GAG) in native cartilage, lower GAG content in regenerative tissue (safranin-O, magnification ×5) (c)