Arthroscopic reattachment of osteochondritis dissecans cartilage flaps of the femoropatellar joint: Long-term results

Reasons for performing study: Long-term efficacy of arthroscopic cartilage reattachment for the treatment of osteochondritis dissecans (OCD) lesions in the equine femoropatellar joint is unknown. Objective: To evaluate radiographic outcome and long-term performance of horses undergoing OCD reattachment. Hypothesis: Separated OCD cartilage flaps may be reincorporated into the joint surface by reattachment rather than flap removal. Methods: Polydioxanone pins were utilised arthroscopically to reattach OCD lesions in 40 of 44 joints from 27 horses. Cartilage was reattached when it had persisting perimeter continuity, the surface was not deeply fissured or irregular, and the cartilage was not protuberant or extensively mineralised. Bone marrow aspirate concentrate was grafted to additional areas denuded of cartilage or alongside reattached cartilage. Results: Breeds included Thoroughbred (n = 18), Quarter Horse (n = 4), Warmblood (n = 3), Standardbred (n = 1) and Arabian (n = 1). Mean age was 9.7 months. Radiographic lesion length was 1.5-6.3 cm. Reattachment alone was used in 32 of 44 affected joints, a combination of debridement and reattachment in 8 joints and debridement alone in 4 joints. One horse was destroyed due to tendon laceration. Of the remaining 26 horses, mean duration of follow-up was 15.6 months (range 2 months-12 years). Radiographic resolution of OCD lesions treated with reattachment was significantly improved at 6 months. Twenty horses had long-term performance data, of which 19 were sound and had reached intended athletic potential. One horse remained lame, and an additional 6 were sound but remained unbroken or were convalescing. Thus, an overall success rate based upon continued soundness in performing horses was 95% (19/20). Conclusion: Cartilage flap reattachment can salvage OCD cartilage by integration with the underlying bone. Potential relevance: Extensive OCD cartilage flaps may be salvaged by reattachment which can result in normal radiographic subchondral bone contour and long-term athletic performance.