Simulation of pelvic osteotomies applied for DDH treatment in pediatric patients using piglet models.

Abstract

Developmental dysplasia of the hip (DDH) is a common hip joint pathology seen in the pediatric orthopedist's practice. Pelvic osteotomies are the reliable surgical option for DDH treatment in walking patients, and 3 osteotomies (Salter, Dega and Pemberton) are widely used in patients under 6 years of age. Plastic changes in hinge points occur during iliac fragment movement, after the performed osteotomy. The locations of these points are described in the literature, but some debate still exists about their true positions. To reveal hinge point locations during a simulation of pelvic osteotomies on biological models. Eighteen piglet pelvis complexes were obtained and separated according to their age. Pelvic osteotomies were simulated, and bone changes were assessed on computed tomography (CT) scans after the performed surgeries. No bone changes were found after Salter osteotomy in younger piglets, while contralateral pubic bone metaphyseal fractures were found in older animals. After Pemberton osteotomy, greenstick fractures in iliac and pubic bones metaphyses in the triradiate cartilage area were revealed in younger and older piglets. After Dega osteotomy, a posterior medial cortical layer fracture of the uncut iliac bone in the greater sciatic notch was found in all piglets. In older piglets, an additional hinge point was detected in the ipsilateral pubic bone metaphysis. It was found that the age of the piglets has an impact on hinge point number and location, and this may be explained by an age-related decrease in pelvic bone and cartilage plasticity. The results of this study may help surgeons to decrease the number of preventable complications during pelvic osteotomies.