Effect of Double Pelvic Osteotomy on Dorsal Acetabular Rim Angle Using Computed Tomography in 27 Dogs

Area of Science:

• Veterinary Orthopedics
• Canine Hip Dysplasia
• Surgical Biomechanics

Background:

• Hip dysplasia is a common developmental orthopedic condition in dogs, leading to joint instability and pain.
• Double pelvic osteotomy (DPO) is a surgical procedure used to correct hip dysplasia by improving acetabular coverage.
• The dorsal acetabular rim angle (DARA) is a key radiographic parameter used to assess acetabular morphology and surgical outcomes in DPO.

Purpose of the Study:

• To quantify the effect of double pelvic osteotomy (DPO) on the dorsal acetabular rim angle (DARA) in a canine clinical population.
• To evaluate the relationship between pre-angled DPO plate angles and the achieved acetabular ventroversion.
• To provide data to assist in implant selection for DPO procedures.

Main Methods:

• Retrospective analysis of computed tomographic (CT) studies from 27 dogs undergoing DPO for hip dysplasia.
• Measurement of DARA on pre- and post-operative CT scans, with short- and long-term follow-up CTs where available.
• Comparison of DARA changes using 30-, 25-, and 20-degree pre-angled DPO plates.

Main Results:

• A significant reduction in DARA was observed immediately post-DPO, with median changes of 23.4, 16.7, and 15 degrees for 30-, 25-, and 20-degree plates, respectively.
• Postoperative DARA measurements remained stable in short- and long-term follow-ups (p > 0.05).
• The actual acetabular ventroversion achieved was consistently less than the predetermined plate angle, with median differences of 6.6, 8.3, and 5 degrees for the 30-, 25-, and 20-degree plates, respectively.

Conclusions:

• DPO significantly corrects the DARA in dogs with hip dysplasia, with sustained results over time.
• The degree of acetabular ventroversion achieved is less than the intended angle of the pre-angled DPO plates.
• These findings are crucial for guiding the selection of appropriate DPO plate angles to optimize surgical outcomes in veterinary patients.