MINIMAL-INVASIVE RECONSTRUCTION OF OSTEOCHONDRAL LESIONS OF THE TALUS BY USE OF A CELL-FREE COLLAGEN SCAFFOLD

Abstract

Introduction: Osteochondral lesions of the talus (OCL III–IV°) need both extensive debridement for revitalisation and osteochondral reconstruction of the joint surface. This can be achieved by autologous cancellous bone-grafting and combination with a cell-free bioresorbable collagen-I/III scaffold. Our first results with this technique are presented.

Methods: 25 patients (13 female, 12 male, mean age 30.9 years) with 26 osteochondral lesions of the talus (OCL III–IV°, 15 right, 11 left, 24 medial, 2 lateral, 1 bilateral case) were treated by minimal-invasive debridement, autologous cancellous bone-grafting and application of a porcine collagen-I/III scaffold (ChondroGide^®) and evaluated prospectively by clinical scoring and MRI. The average follow-up was 23.2 (6–36) months. The mean defect size was 2.0 cm², the mean depth 0.7 cm. 14 defects have had at least one (1–3) operation on the defect before. By the use of a distractor a malleolar osteotomy could be avoided in all cases.

Results: The AOFAS-score increased from 67.4 ± 12.2 to 89.5 ± 7.4 points (p< 0.01, t-test). On a visual 10-point scale pain decreased significantly from 6.2 to 1.7 while subjective ankle function improved from a mean of 4.4 ± 1.9 to 7.2 ±1.5. The results were rated excellent in 10/26 cases (38.4%), good in 14/26 (53.8) and fair in 2/26 (7.8%) cases. MRI follow-ups showed a complete or nearly complete defect filling. In two ankles a second-look arthroscopy unveiled the defects filled completely by a regenerative tissue with a smooth surface and good bonding. Full-core biopsies showed a mixed, mostly fibrocartilagenous tissue.

Conclusion: By combination of cancellous bone-grafting with a cell-free collagen-I/III scaffold typical osteochondral lesions of the talus can be adressed effectively in a minimal-invasive one-step procedure. By utilizing mesenchymal stem cells (MSC) for an autogenous reparation process the use of expensive cultured chondrocytes is not necessary. The results concerning clinical functional improvement, pain reduction and patients’ satisfaction as well as defect filling in MRI are promising.