Total Hip Arthroplasty for Crowe Type IV Developmental Dysplasia of the Hip Using a Titanium Mesh Cup and Subtrochanteric Femoral Osteotomy.

Background: Treatment of Crowe IV developmental dysplasia of the hip (DDH) with total hip arthroplasty (THA) reconstructs the true acetabulum, which improves hip biomechanics and function. However, restoration of the native acetabulum may lead to limb lengthening and traction neuropraxia. The purpose of this study is to describe the short term results of a retrospectively reviewed series of patients with Crowe IV DDH treated with THA using a titanium mesh cup, cemented liner, and subtrochanteric femoral shortening osteotomy.

Methods: Eighteen patients (21 hips) with an average age of 47 years (age range: 28-61 years) with Crowe IV DDH underwent reconstructive THA and subtrochanteric femoral shortening osteotomy between September 2005 and February 2014. Follow up was assessed at 1, 3, 6, 9, and 12 months post operatively and then annually after the first year. The average follow up was 3.5 years (range 0.5-9 years). At each follow up visit, radiographs were used to assess for osteolysis and subsidence. Preoperative and postoperative patient reported outcomes including Harris Hip Score and Modified Merle d'Aubigne Hip Score were compared.

Results: At the minimum 6 month follow up, all radiographic assessments showed no signs of osteolysis or subsidence of the implants. Both the Harris Hip Score and Modified Merle d'Aubigne Hip Score improved from preoperative assessments (p<0.05). Three patients developed symptoms of sciatic nerve neuropraxia that subsequently resolved.

Conclusion: THA of Crowe IV DDH by reconstructing the acetabulum with bone graft, a titanium mesh cup, cemented liner, and subtrochanteric femoral shortening osteotomy demonstrated no osteolysis or subsidence and improved function with a low incidence of sciatic nerve palsy at short term follow up.Level of evidence: IV.