An in-depth analysis of young adults with osteonecrosis secondary to developmental dysplasia of the hip who underwent total hip arthroplasty

Abstract

Background: Patients with osteonecrosis of the femoral head secondary to DDH frequently require total hip arthroplasty (THA), but it is not well understood which factors necessitate this requirement. We determined the incidence of THA in patients who have osteonecrosis secondary to DDH and factors associated with need for THA.

Methods: We included patients who received closed or open reductions between 1995 and 2005 with subsequent development of osteonecrosis. We determined osteonecrosis according to Bucholz and Ogden; osteoarthritis severity (Kellgren-Lawrence), subluxation (Shenton's line); neck-shaft angle; and acetabular dysplasia (centre-edge and Sharp angles). We also recorded the number of operations of the hip in childhood and reviewed case notes of patients who received THA to describe clinical findings prior to THA. We assessed the association between radiographic variables and the need for THA using univariate logistic regression.

Results: Of 140 patients (169 hips), 22 patients received 24 THA (14%) at a mean age of 21.3 ± 3.7 years. Associated with the need for THA were grade III osteonecrosis (OR 4.25; 95% CI 1.70-10.77; p = 0.0019), grade IV osteoarthritis (21.8; 7.55-68.11; p < 0.0001) and subluxation (8.22; 2.91-29.53; p = 0.0003). All patients who required THA reported at least 2 of: severe pain including at night, stiffness, and reduced mobility. Acetabular dysplasia and number of previous operations were not associated with the need for THA.

Conclusions: We identified a 14% incidence of THA by age 34 years in patients with osteonecrosis secondary to DDH. Grade III osteonecrosis (global involvement femoral head and neck) was strongly associated with THA, emphasising the importance to avoid osteonecrosis when treating DDH.

Keywords: DDH; Osteonecrosis; Total hip arthroplasty.

Fig. 1

Flow diagram showing patient eligibility and participation. THA, total hip arthroplasty

Fig. 2

A A pelvic radiograph obtained 15 years after open reduction, Salter innominate osteotomy and femoral varus de-rotation osteotomy. It shows grade III osteonecrosis of the left hip in a 17-year-old girl. There is total femoral head involvement, marked acetabular dysplasia and subluxation of the hip. She had a positive Trendelenburg gait and 1 cm difference in leg lengths. B Pelvic radiograph of the same patient 5 years post THA, performed at age 18 years

Fig. 3

Radiographs representing Grade I, Grade II, Grade III, and Grade IV (from left to right) of the Bucholz-Ogden classification for osteonecrosis secondary to DDH

Fig. 4

Graph showing the cumulative occurrence of THA (solid line) and 95% confidence interval (dotted line)