The sacroiliac joints: evaluation using nuclear scintigraphy. Part 2: Lame horses

Area of Science:

• Equine diagnostic imaging
• Nuclear medicine in veterinary science
• Equine lameness diagnostics

Background:

• Diagnosing sacroiliac (SI) joint disease in horses is challenging using clinical examination alone.
• Lameness may present with asymmetrical radiopharmaceutical uptake in the SI region, even without primary SI joint pain.

Purpose of the Study:

• To determine if differences in radiopharmaceutical uptake can identify horses with suspected SI joint region pain.
• To compare radiopharmaceutical uptake ratios in horses with and without SI joint disease.

Main Methods:

• Scintigraphic imaging of the pelvic region in 234 lame horses, 40 normal horses, and 41 horses with suspected SI joint disease.
• Analysis of radiopharmaceutical uptake ratios between the fifth lumbar vertebra (L5) and tubera sacrale (TS) or SI joints.
• Assessment of left-right symmetry and quantitative profile analysis.

Main Results:

• Lame horses showed greater asymmetry in tubera sacrale radiopharmaceutical uptake compared to normal horses.
• Horses with suspected SI joint disease exhibited higher L5/TS and L5/SI joint uptake ratios than normal horses.
• Quantitative analysis of left-right asymmetry aided in differentiating SI joint disease from other lameness causes.

Conclusions:

• Scintigraphy is a valuable tool for identifying SI joint disease in horses, particularly when used alongside clinical signs.
• Diagnosis should not rely solely on scintigraphy due to overlapping radiopharmaceutical uptake patterns between affected and unaffected horses.