Autologous Bone Plug Supplemented With Autologous Chondrocyte Implantation in Osteochondral Defects of the Knee.

Bhattacharjee, Atanu; McCarthy, Helen S.; Tins, Bernhard; Roberts, Sally; Kuiper, Jan H.; Harrison, Paul E.; Richardson, James B.

Abstract

BACKGROUND: Structural and functional outcome of bone graft with first- or second-generation autologous chondrocyte implantation (ACI) in treating cartilage and subchondral bone defect has not been reported previously. PURPOSE: To evaluate the outcome of simultaneous transplantation of an autologous bone plug with first- or second-generation ACI for restoration of concomitant subchondral bone and full-thickness cartilage defect in the femoral condyle of the knee. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Seventeen patients (mean ± SD age, 27 ± 7 years; range, 17-40 years)-12 with osteochondritis dissecans (International Cartilage Repair Society [ICRS] grades 3 and 4) and 5 with an isolated osteochondral defect (ICRS grade 4)-had the defect reconstructed with implantation of a unicortical autologous bone graft combined with ACI (the OsPlug technique). Functional outcome was assessed with Lysholm scores obtained preoperatively and at 1 and 5 years postoperatively. The repair site was evaluated with the Oswestry Arthroscopy Score (OAS), MOCART score (magnetic resonance observation of cartilage repair tissue), and ICRS II histology score. Formation of a subchondral lamina and lateral integration of the bone grafts were evaluated from magnetic resonance imaging scans. RESULTS: The mean defect size was 4.5 ± 2.6 cm(2) (range, 1-9 cm(2)), and the mean depth was 11.3 ± 5 mm (range, 5-18 mm). The preoperative Lysholm score improved from 45 (interquartile range [IQR], 24; range, 16-79) to 77 (IQR, 28; range, 41-100) at 1 year (P = .001) and 70 (IQR, 35; range, 33-91) at 5 years (P = .009). The mean OAS of the repair site was 6.2 (range, 0-9) at a mean of 1.3 years. The mean MOCART score was 61 ± 22 (range, 20-85) at 2.6 ± 1.8 years. Histology demonstrated generally good integration of the repair cartilage with the underlying bone. Poor lateral integration of the bone graft, as assessed on magnetic resonance imaging scan, and a low OAS were significantly associated with a poor Lysholm score and failure. A total of 3 patients had treatment failure, with 1 requiring total knee replacement at 5 years (Lysholm score of 33 at failure) and the other 2 requiring further surgical intervention because of persistent symptoms at 2 and 4 years, respectively (both had Lysholm score of 45 at failure). The Lysholm score in these patients before failure were still noted to be higher than at the preoperative level. CONCLUSION: The OsPlug technique shows significant improvement of functional outcome for up to 5 years in patients with high-grade osteochondritis dissecans or osteochondral defect. This is the first report describing association of bone graft integration with functional outcome after such a procedure. It also demonstrates histologic evidence of integration of the repair cartilage with the underlying bone graft.

Citation

Bhattacharjee, A., McCarthy, H. S., Tins, B., Roberts, S., Kuiper, J. H., Harrison, P. E., & Richardson, J. B. (2016). Autologous Bone Plug Supplemented With Autologous Chondrocyte Implantation in Osteochondral Defects of the Knee. American Journal of Sports Medicine, 44(5), 1249 - 1259. https://doi.org/10.1177/0363546516631739

• Journal Article Type: Article
• Acceptance Date: Mar 10, 2016
• Publication Date: Mar 10, 2016
• Journal: American Journal of Sports Medicine
• Print ISSN: 0363-5465
• Publisher: SAGE Publications
• Peer Reviewed: Peer Reviewed
• Volume: 44
• Issue: 5
• Pages: 1249 - 1259
• DOI: https://doi.org/10.1177/0363546516631739
• Keywords: knee; osteochondritis dissecans; autologus chondrocyte implantation; osteochondral defects
• Publisher URL: http://ajs.sagepub.com/content/44/5/1249