Positron emission tomography assessment of metacarpal/metatarsal condylar fractures post surgical repair: Prospective study in 14 racehorses.
Authors: Bergstrom Thomas C, Spriet Mathieu, O'Brion Julie, Carpenter Ryan
Journal: Veterinary surgery : VS
Summary
# Editorial Summary: PET Imaging of Condylar Fractures in Racehorses Metacarpal and metatarsal condylar fractures remain a significant orthopaedic challenge in racing Thoroughbreds, yet little is known about the underlying biomechanical stress patterns preceding these injuries. Bergstrom and colleagues used 18F-sodium fluoride positron emission tomography (PET) to map bone metabolic activity in 14 racehorses within 4 days of surgical repair, with follow-up imaging at 3 and 5 months, comparing injured limbs to their contralateral pairs using a validated grading system. A striking finding emerged: all six horses with abaxial (non-parasagittal groove) lateral condylar fractures showed abnormal uptake in the contralateral limb's lateral palmar condyle, indicating pre-existing stress remodelling in clinically sound horses—a pattern suggesting bilateral biomechanical vulnerability rather than isolated injury. Conversely, horses sustaining parasagittal groove fractures showed this contralateral uptake in only 3 of 8 cases, indicating different mechanical aetiology. Post-operatively, four horses developed periarticular uptake consistent with early degenerative joint disease, and notably, none of these four returned to racing, whereas horses with isolated fracture-site uptake had better outcomes. These observations suggest PET can identify horses at risk before catastrophic fracture occurs, stratify prognosis during rehabilitation, and potentially guide preventative management—offering practitioners a novel tool for early intervention in high-risk individuals.
Read the full abstract on PubMed
Practical Takeaways
- •PET imaging early after condylar fracture repair can identify pre-existing contralateral limb lesions and inform prognosis—horses with contralateral stress remodeling may require modified rehabilitation
- •Development of periarticular uptake postoperatively strongly predicts failure to return to racing; consider this imaging finding when counseling owners on realistic return-to-racing expectations
- •PET's ability to detect subclinical joint disease and stress remodeling may help prevent catastrophic injury by identifying at-risk racehorses before they return to training
Key Findings
- •All 6 horses with abaxial (non-PSG) lateral condylar fractures showed stress remodeling uptake in the contralateral limb, indicating pre-existing lesions
- •Four horses (29%) developed periarticular uptake suggestive of degenerative joint disease postoperatively, and none of these returned to racing successfully
- •Lateral condylar fractures alone presented atypical minimal/mild medial condyle uptake, which is unusual in front limb fractures in racehorses in full training
- •18F-NaF PET identified specific uptake patterns within 4 days of surgical repair that correlated with postoperative complications and racing outcomes