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

The study is focused on exploring a more definitive method for diagnosing Sacroiliac (SI) joint disease in horses using nuclear scintigraphy. Comparisons were made between horses with presumptive SI joint disease, sound horses, and lame horses with different conditions, examining the radiopharmaceutical uptake in different regions.

Objective and Methodology

• The study aimed to identify whether differences in radiopharmaceutical activity are capable of distinguishing horses with presumed SI joint pain. It also sought to learn if lameness not related to SI joint pain leads to unusual radiopharmaceutical uptake in the SI joints and associated areas.
• The research was done on three groups of horses: Group I consisting of 234 horses with lameness unrelated to the SI joints, Group N comprising of 40 normal horses in active work, and Group II made up of 41 horses with suspected SI joint disease.
• Several variables were considered in the study’s analysis like the age, sex, lame limb, and discipline of the horses in Group I. The scintigraphic images of the pelvic area of the horses were assessed and compared, using profile analysis and comparing the uptake average count per pixel between various regions.

Results

• The research discovered that lame horses (Group I) demonstrated a higher frequency of radiopharmaceutical uptake imbalance in the tubera sacrale (a part of the pelvic bone) compared to physically sound horses.
• Group I horses with lameness in the right hindlimb showed a larger RSI/LSI ratio of radiopharmaceutical uptake compared to normal horses. There was also an increase in radiopharmaceutical uptake in certain areas in Group I as these horses aged.
• Horses that were suspected to have SI joint disease (Group II) showed heightened radiopharmaceutical uptake ratios in specific regions when compared with normal horses. This indicates a possible relationship between SI joint disease and such uptake patterns.
• Distinct left-right asymmetry revealed through quantitative examination or profile analysis was useful in differentiating horses with symptoms indicating SI joint disease from both normal horses and those impaired due to other causes.

Conclusion

• It was concluded that scintigraphic evaluation of the SI region can be helpful in identifying SI joint disease when combined with other symptoms indicative of the diagnosis. However, the diagnosis should not solely rely on this method due to a potential overlap in radiopharmaceutical uptake ranges between horses with SI joint disease, normal horses, and those exhibiting lameness from different causes.