Classically, treating horses with small defects in the cartilage lining the ends of joints and the layer of bone directly underneath (the subchondral bone) could be summarized by the mantra, "If in doubt, cut it out." Now, Cornell University surgeons are saying, "If you want sound, pin it down."
"The traditional means of treating OCD (osteochondritis dissecans) lesions in the (stifle) joint have been by removing the flap of cartilage that is dislodged from the underlying bone and debriding or curetting (scraping out) the diseased subchondral bone," said Alan J. Nixon, BVSc, Dipl. ACVS, director of the Comparative Orthopaedic Laboratory at Cornell University in Ithaca, N.Y.
This treatment approach can result in permanent loss of the subchondral bone, which in some cases can cause the joint to become unstable. An unstable joint negatively impacts soundness, performance, and can lead to the development of osteoarthritis.
In an attempt to abrogate these OCD-related complications, Nixon and colleagues tried a different approach: reattaching the cartilage to the underlying bone using tiny degradable pins.
The retrospective study evaluated 44 joints on 27 horses that were treated between 1996 and 2010. The treating veterinarians assessed the horses three to six months after treatment and again at an average time of 15.6 months.
Key findings included:
- Most (32 of 44) cartilage flaps could be reattached using the pins alone;
- Eight lesions needed debriding before pinning the cartilage;
- Four lesions in the same or opposite stifle were not amenable to pinning and required the standard debriding and cartilage removal; and
- Of the 20 horses with long-term performance data available, 19 had reached their intended performance level and had no evidence of lameness post-treatment.
"The high success rate and lack of postoperative complications makes cartilage reattachment a promising treatment option for OCD lesions; however, degenerate and irregularly shaped lesions are not likely to benefit from this approach," Nixon noted. "The cartilage must be worth reattaching to justify the ... pins."
The study, "Arthroscopic reattachment of osteochondritis dissecans cartilage flaps of the femoropatellar joint: Long-term results," will be published in an upcoming edition of the Equine Veterinary Journal. The abstract is currently available online.
Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.