Oral Presentation 24th International Conference of Racing Analysts and Veterinarians 2026

Managing a precursor injury: Regulatory surveillance of unicortical condylar fractures in 77 Thoroughbreds (129122)

Motoi Nomura 1 , Yusuke Katsurashima 2 , Mai Iimori 3 , Fumiaki Mizobe 2 , Kenta Mitsuda 2 , YUHIRO ISHIKAWA 1
  1. Equine Research Institute, Japan Racing Association, Shimotsuke, Tochigi, Japan
  2. Miho Training Center, Japan Racing Association, Inashiki, Ibaraki, Japan
  3. Ritto Training Center, Japan Racing Association, Ritto, Shiga, Japan

Unicortical condylar fractures (UCF) of the metacarpal or metatarsal condyle are increasingly recognized with advances in diagnostic imaging. These injuries are important as potential precursors to complete or catastrophic fractures in racehorses. This retrospective study aimed to describe the outcomes of Thoroughbred racehorses diagnosed with UCF in Japan.

This study included horses diagnosed with UCF for the first time based on radiographic and/or low-field standing MRI findings between May 2015 and April 2025. Data collected included the lesion location, treatment, and outcome (return to racing, the days to return to racing, occurrence of subsequent fracture).

Seventy-seven cases (75 forelimbs, 2 hindlimbs) were identified, with 13 cases occurring during racing and 64 during training. Twenty-six cases needed MRI to detect UCF or confirm an acute lesion. Among 62 horses intended to return to racing (15 retired immediately after diagnosis), 58 completed follow-up, and 51 successfully returned. The median time to return to racing was 249 days (range 89-585 days), with no significant difference based on lesion location (10 medial and 41 lateral condyles) or treatment method (24 surgical and 27 conservative). During rehabilitation, two horses treated conservatively experienced complications: one reinjured the original fracture site, and the other developed UCF in the contralateral limb. After returning to racing, two horses treated conservatively sustained catastrophic fetlock fractures. Additionally, one horse with screw fixation developed a fracture in metacarpal condyle of the contralateral limb, and another developed a catastrophic fracture in metacarpal condyle of the contralateral limb.

These findings suggest that horses diagnosed with UCF can successfully return to racing following accurate diagnosis and adequate recovery time, regardless of the lesion location or treatment method. However, continued monitoring is necessary, even after returning to racing, due to the potential risk of re-injury and catastrophic failure.