Nonsurgical and surgical management of metacarpo/metatarsophalangeal joint dorsal chip fracture in the Thoroughbred racehorse.

Abstract: Arthroscopy is considered the treatment of choice for dorsal osteochondral chip fractures of the metacarpo/metatarsophalangeal (MCP/MTP) joints in the racehorse; however, there is no published research on non-surgical management of this injury. Objective: To compare clinical features, intra-articular medication use and return to racing in Thoroughbred racehorses with non-surgically (non-SX) or surgically (SX) managed MCP/MTP dorsal chip fracture. Methods: Retrospective observational study conducted between 2006 and 2014. Methods: Radiographs of Thoroughbred racehorses were reviewed to identify MCP/MTP dorsal osteochondral chip fractures. Clinical and intra-articular medication data were obtained from veterinary records, and return to racing data from a public online resource. Results: A total of 98 MCP/MTP horses with dorsal chip fractures were identified (70 non-SX, 28 SX). Median age was 2 years (range 2-7 years). Osteochondral chip fractures predominantly involved the forelimbs (n = 92, 93.9%) and the majority were considered by the treating clinician to be clinically active (n = 85, 86.7%). Significantly more SX horses had a reported ongoing problem associated with the affected joint than non-SX horses (P = 0.002), however there was no significant difference between non-SX and SX horses in the number of intra-articular medications of affected joint per month of follow-up (P = 0.22). The proportion of horses racing post-diagnosis was not significantly different between non-SX (55/70; 78.6%, 95% CI 69.0, 88.2%) and SX horses (24/28; 85.7%, 95% CI 72.8, 98.73%) (P = 0.57). Median time to first start following diagnosis for non-SX (106 days, range 1-326) was significantly shorter than for SX horses (203 days, range 9-559) (P = 0.002). Conclusions: Management technique was not randomised or blinded, with few surgically managed horses. Conclusions: The results contribute to the current evidence base used to guide management of osteochondral chip fractures of the MCP/MTP joints in the racehorse, and indicate that non-surgical management may be a valid treatment option for some injuries.