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

This study aimed to quantify the effect of double pelvic osteotomy (DPO) on dorsal acetabular rim angle (DARA) in a clinical cohort of dogs.Retrospective study.The DARA was measured on computed tomographic (CT) studies of 27 client-owned dogs that underwent DPO due to hip dysplasia. The change in DARA was determined for 30-, 25- and 20-degree preangled-locking DPO plates. The preoperative DARA was compared to the immediate postoperative DARA, and where available, the postoperative DARA was compared to short- and long-term DARA measurements.27 dogs underwent DPO, resulting in 49 hips available for analysis. The median preoperative DARA was 16.3 degrees (Q1-Q3, 12.3-22.2) and 17.6 degrees (Q1-Q3, 12.42-1.0) for right and left hip, respectively. The median postoperative DARA was -4.5 degrees (Q1-Q3, [-8.8]-[-1.3]) for the right hip and -4.1 degrees (Q1-Q3, [-7.6] to 5.8) for the left hip. The median change in DARA was 23.4 degrees (Q1-Q3, 17.5-26.15), 16.7 degrees (Q1-Q3, 12.2-20) and 15 degrees (Q1-Q3, 14.1-15.2) for a 30-, 25- and 20-degree plate, respectively. Short-term follow-up CT was available for 16 dogs (30 hips) at a median of 48 days (Q1-Q3, 45-57 days) and long-term follow-up CT was available for 12 dogs (22 hips) at a median of 386 days (Q1-Q3, 325-557). The postoperative DARA and short- and long-term DARA measurements did not change significantly (p > 0.05).The acetabular ventroversion achieved with DPO is less than the predetermined plate angle. The median differences for the 30-, 25-, and 20-degree plates are 6.6, 8.3, and 5 degrees, respectively.The results can aid in implant selection for DPO.