Patient-Specific Templates for Triple Pelvic Osteotomy in Children with Dysplastic Hip Subluxation (Preliminary Results)

Abstract

Purpose of the study — to evaluate the degree of correction of acetabular spatial position after triple pelvic osteotomy using patient-specific templates in children with dysplastic hip subluxation. Materials and methods. Study included 30 patients (30 hips) with dysplastic hip subluxation aging from 14 to 18 years (mean age of 16.3±1.4). All children were divided into two groups — main group consisted of 15 children (15 hips) who underwent triple pelvic osteotomy using patient-specific templates produced by 3D modeling and prototyping technology; control group consisted of 15 children (15 hips) who underwent triple pelvic osteotomy based on standard preoperative planning. X-ray and CT of hip joints was made in all patients. Results. Parameters of acetabular spatial position as well as integral parameters which define the ratio between acetabulum and femoral components and hip stability were in the range of normal variation in patients of the main group. Similar average parameters in patients of control group were below the lower margin of the physiological norm (p<0.05). Besides, the values of standard deviation of abovementioned X-ray parameters in some patients of control group demonstrated pronounced variability characterized by hyper- and hypo-correction values of spatial position of acetabular fragment. Conclusion. In contrast to standard preoperative planning the use of patient-specific templates during re-orienting triple pelvic osteotomy in children with dysplastic hip subluxation allows to level out possible errors in three-dimensional acetabulum positioning towards hyper- and hypo-correction (p<0.05) of pelvic component. This creates conditions to ensure adequate hip stability which is confirmed by key x-ray indices with values within normal reference range.