- Veterinary View Box
- Posts
- DPO Delivers: CT Confirms Better Hip Coverage and Less Subluxation After Surgery in Dogs
DPO Delivers: CT Confirms Better Hip Coverage and Less Subluxation After Surgery in Dogs
Veterinary and Comparative Orthopaedics and Traumatology, 2025
Obi Veterinary Education
December 03, 2025
Daniel C. Lomas, Ricky Cashmore, Daniel James, Paul L. Jenkins
Background
Canine hip dysplasia is a developmental condition that predisposes dogs to joint laxity and osteoarthritis. Double pelvic osteotomy (DPO) was developed to improve joint congruity and reduce subluxation by rotating the acetabulum without osteotomizing the ischium. While DPO’s clinical benefits have been described, its specific effect on dorsolateral subluxation (DLS) of the femoral head under weight-bearing conditions had not been evaluated in vivo.
Methods
This retrospective observational study evaluated 24 client-owned juvenile dogs (45 hips) that underwent DPO between 2015 and 2021. Inclusion required clinical lameness, hip laxity, and minimal radiographic osteoarthritis. Computed tomography (CT) scans were obtained preoperatively, immediately postoperatively, and at follow-up (median 51 days) to measure DLS score—an objective metric of femoral head coverage in a simulated weight-bearing position. A paired t-test and ANOVA were used to assess the effect of DPO and plate angle on DLS scores.
Results
The mean DLS score increased significantly from 36.1% preoperatively to 71.4% immediately after DPO and was maintained at 70.0% at follow-up (p < 0.001). Dogs treated with 30° plates showed the greatest improvement in DLS score (mean increase 39.8%), followed by 25° (30.1%) and 20° plates (22.8%). No significant association was found between DLS improvement and age, weight, surgical side, or surgeon. The technique proved repeatable and feasible with CT, offering accurate and consistent quantification of femoral head coverage.
Limitations
Limitations included small sample size, variation in imaging sedation protocols, lack of long-term follow-up, and absence of clinical outcome correlation. Differences in CT positioning and use of multiple plate designs may have introduced variability. Histologic confirmation of cartilage health and data on actual osteoarthritis progression were not available.
Conclusions
DPO significantly increases femoral head coverage in a weight-bearing position, reducing dorsolateral subluxation in dysplastic hips. This objective improvement in joint congruency supports DPO’s utility in mitigating early-stage hip dysplasia. CT-based DLS assessment may offer a more functionally relevant alternative to traditional radiographic measures and should be considered for pre- and post-surgical evaluation.
Method of measurement of dorsolateral subluxation (DLS) score. This figure demonstrates the method of measurement of the DLS. 3D
multi-planar reconstruction is used to obtain a transverse image at the lateral-most point of the central dorsal acetabular rim. A line is
drawn connecting the dorsal acetabular rims. The femoral head diameter is measured using a circular tool. Two perpendicular lines are
drawn down from the original line at the level of the medial-most portion of the femoral head (Line A) and the lateral-most portion of the
acetabulum (Line B). The following calculation is performed to obtain the DLS score (distance between Line A and Line B/diameter of the femoral
head) 100.
How did we do? |
Disclaimer: The summary generated in this email was created by an AI large language model. Therefore errors may occur. Reading the article is the best way to understand the scholarly work. The figure presented here remains the property of the publisher or author and subject to the applicable copyright agreement. It is reproduced here as an educational work. If you have any questions or concerns about the work presented here, reply to this email.