Accuracy of dog positioning before total hip replacement is high and not influenced by surgical experience

To evaluate the accuracy of dog positioning before total hip replacement (THR) and the influence of experience and dog body condition score (BCS) on positioning accuracy.

6 experienced THR surgeons and 11 veterinarians without THR experience positioned 4 cadavers (2 each with BCSs of 4/9 and 6/9) for THR 3 times using a vacuum bean bag. Accuracy was evaluated using fluoroscopy in 2 orthogonal planes: the transverse and dorsal planes.

Mean positioning error was < 4° in both the transverse and dorsal planes. The mean deviation in the transverse plane for veterinarians with THR experience (3.6°) did not differ from the deviation for veterinarians without experience (3.8°; P = .398). The mean absolute deviation in the dorsal plane for veterinarians with THR experience (3.2°) did not differ from the mean absolute deviation for veterinarians without experience (3.7°; P = .930). Malpositioning > 10° in either plane occurred in 17 of 204 positionings (8%) and did not differ in frequency among experienced and inexperienced veterinarians. No difference in positioning accuracy was noted between cadaver BCS groups.

Freehand patient positioning before THR is generally precise and does not appear to improve with additional experience or lean patient BCS.

Most dogs positioned using a vacuum bean bag and freehand (nonfluoroscopy guided) positioning are accurately positioned, and positioning errors > 10° occur < 10% of the time. Positioning accuracy may not increase with lean patient BCS or additional experience for veterinary surgeons doing THR.