Necrosis of the collateral cartilage of the distal phalanx in horses: 16 cases (1970-1985).

The medical records of 16 horses with necrosis of the collateral cartilage of the distal phalanx were reviewed. Typical history included a laceration or puncture wound over the affected cartilage, resulting in persistent drainage proximal to the coronary band. All horses had signs of lameness. The duration of drainage prior to admission to the hospital ranged from 5 days to 5 months. The involved cartilages were left front lateral (n = 4), right front lateral (n = 5), left rear lateral (n = 1), right rear lateral (n = 4), left front medial (n = 1), and left rear medial (n = 1). The affected cartilage was curetted or resected in 13 horses, and conservative treatment was used in 3 horses. Follow-up information on 15 horses (2 to 72 months after discharge) revealed that 66% were sound and able to perform at their previous level. One horse was euthanatized 2 months after discharge from the hospital because it had septic arthritis of the distal interphalangeal joint. The outcome of treatment for each horse was evaluated with respect to the duration of drainage and the method of treatment. Horses with drainage of less than 1 month's duration had a better prognosis for eventual soundness, compared with horses with drainage of greater than or equal to 1 month's duration prior to initiation of treatment. Nine of the 13 horses managed surgically and 1 of the 3 horses managed conservatively were sound at follow-up evaluation.