Relationship between scintigraphic and radiographic evaluations of spinous processes in the thoracolumbar spine in riding horses without clinical signs of back problems.
Authors: Erichsen C, Eksell P, Holm K Roethlisberger, Lord P, Johnston C
Journal: Equine veterinary journal
Summary
# Editorial Summary: Scintigraphic and Radiographic Findings in Clinically Normal Horses' Thoracolumbar Spines Distinguishing clinically significant spinal pathology from incidental findings remains a diagnostic challenge in equine back pain, prompting Erichsen and colleagues to establish baseline imaging patterns in asymptomatic horses. Thirty-three apparently normal riding horses underwent both scintigraphy (with radiopharmaceutical uptake graded as none, mild, moderate or severe) and radiography (evaluating sclerosis, radiolucencies and interspinous spacing from T10–L2), revealing a striking lack of uniformity in imaging-normal populations. Only 7 of 33 horses demonstrated completely normal findings on both modalities, whilst 26 horses displayed some combination of increased radiopharmaceutical uptake, sclerotic changes, radiolucencies or altered interspinous spacing—predominantly in the T13–18 region and typically of mild grade. This work underscores the critical limitation of interpreting isolated radiographic or scintigraphic abnormalities as clinically relevant; practitioners cannot confidently attribute back pain to spinous process pathology based on imaging alone without correlating findings to clinical signs, lameness assessment and ridden performance. Future comparative studies between asymptomatic and symptomatic populations using identical imaging protocols will be essential for establishing which specific changes—if any—warrant treatment intervention.
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Practical Takeaways
- •Radiographic and scintigraphic findings of spinous process changes are extremely common in clinically normal riding horses and should not be automatically interpreted as the cause of back pain
- •The presence of structural changes or increased radiopharmaceutical uptake in the thoracolumbar spine does not necessarily indicate pathology requiring treatment
- •Clinical diagnosis of equine back pain cannot rely on imaging findings alone; correlation with clinical signs, ridden behaviour, and response to treatment is essential
Key Findings
- •Only 7 of 33 clinically normal horses had no scintigraphic or radiographic findings of spinous process changes
- •26 horses showed findings predominantly located T13-18, mostly mild in severity
- •Radiographic changes included sclerosis in 16 horses, radiolucencies in 12 horses, and abnormal spacing (<4 mm) in 22 horses
- •Wide spectrum of scintigraphic and radiographic changes in asymptomatic horses makes it impossible to interpret such findings as clinically significant without comparison to symptomatic horses