34th Annual Scientific Meeting proceedings

Objectives:

Accurate positioning of the acetabular component of total hip replacements (THRs) is critical to the successful outcome of surgery and is dependent on accurate patient positioning. This study aims to assess the accuracy of experienced THR surgeons vs. veterinarians inexperienced in THR at freehand patient positioning to achieve true lateral recumbency.

Methods:

Six experienced THR surgeons (>200 hip arthroplasties each) and 11 licensed veterinarians without THR experience performed freehand positioning on four canine cadavers using a commonly utilized vacuum bean bag patient positioning device. Accuracy was assessed in two planes (dorsal and transverse) using fluoroscopy. 

 

Results:

Overall, mean deviation from true lateral was less than 4 degrees in both the transverse and dorsal planes. Malpositioning by greater than 10 degrees in either plane occurred in 8.3% of positioning attempts and was not different between groups. Mean deviation in the transverse plane for experienced THR surgeons was 3.58 vs. 3.80 degrees for veterinarians inexperienced in THR. Mean deviation in the dorsal plane for experienced THR surgeons was 3.19 degrees vs. 3.68 degrees for veterinarians inexperienced in THR. Neither of these differences was statistically significant.

Conclusions:

Fluoroscopic assessment of cadaver positioning identified average errors within what would generally be considered the “safe zone”  (less than 10 degrees) in both the transverse and dorsal planes with freehand positioning of cadavers. No significant difference was identified between experienced total hip surgeons and veterinarians inexperienced in THR in freehand positioning accuracy.