Ultrasound may improve detection of humeral stress fractures

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Ultrasonography may give equine veterinarians a more practical way to detect a hard-to-image but high-consequence injury in racehorses: caudoproximal humeral stress fracture. In a clinical case series published in Equine Veterinary Journal, investigators from UC Davis and collaborators reviewed seven Thoroughbred racehorses seen from 2013 through 2021 and found that ultrasound identified 9 of 10 caudoproximal humeral stress fractures, including lesions that can be difficult to confirm early with radiography. The authors reported that these horses typically presented with severe forelimb lameness after breezing or galloping, and that ultrasound also helped monitor healing over time. (pmc.ncbi.nlm.nih.gov)

Why it matters: For veterinary professionals, the study points to a lower-cost, more accessible screening option when nuclear scintigraphy, still considered the gold standard for detecting high bone metabolic activity, isn't readily available. That matters because complete humeral fractures in racehorses have been linked to pre-existing stress injuries, and early diagnosis can support rest and rehabilitation before a lesion progresses. The paper also reinforces a practical takeaway: bilateral imaging should be considered in suspected cases, since 3 of the 7 horses in the series were bilaterally affected despite unilateral lameness. (pmc.ncbi.nlm.nih.gov)

What to watch: Whether larger studies confirm ultrasound’s performance in other humeral fracture locations, and whether more racetrack and referral practices adopt bilateral shoulder-region scanning earlier in the workup. (pmc.ncbi.nlm.nih.gov)