Leg Length Balancing In Total Hip Arthroplasty For Adult Crowe Type IV Developmental Dysplasia Of The Hip Patients

[Objective]To investigate the clinical application and efficacy of leg length balancing in totalhip arthroplasty (THA) for adult Crowe type IV developmental dysplasia of the hip(DDH).[Methods]From July2009to January2012,39patients (41hips) were treated with primaryTHA for the treatment of Crowe type IV developmental dysplasia of the hip. Theindication for all THAs was severe pain associated with stiffness and limitation inperforming daily activities. There were3men and36women with an average age of54.1years (range,38years~75years) at operation. According to different situations ofdislocation, pelvic tilt and lumbar scoliosis, the patients were classified into4sub-types: Type I was bilateral symmetric dislocation.Type II was one sidedislocation with the other side normal and no pelvic tilt.Type III was one sidedislocation with the other side normal and pelvic tilt. Type IV was bilateral asymetricdislocation. We made different plans and balanced the leg length accordingly. Thepreoperative and postoperative leg length and Harris score were compared. The SF-12health score were obtained.[Results]The subtype include:2patients of Type I,18patients of Type II,6patients of TypeIIIA,9patients of Type IIIB and4patients of Type IV. The average follow up was36months(range,21months~51months).20months after the operation, the average leg length inequality was significantly improved from (-5.1±1.6)cm(range,-7cm~0cm) to(-1.2±0.9)cm(range,-4cm~0cm)(P＜0.01).The average Harris hip score wassignificantly increased from (39.3±7.4) points (range,19~53) to (88.4±8.1) points(range,67~96).The postoperative average SF-12health score was: PCS52.3(range,37.8~52.5)， MCS55.1(range,45.3~57.7).13THAs was performed withshortening osteotomy. The stems were stable and all osteotomies united. There wereno loosening, no infections, no dislocation, no neurovascular injuries and no deepvenous thrombosis.[Conclusions]1. Total hip arthroplasty is a safe and effective method for the treatment of adultCrowe Ⅳ developmental dysplasia of the hip patients.2. Total hip arthroplasty for Crowe Ⅳ developmental dysplasia of the hip patients isdifficult and challenging, with higher incidence of postoperative limb lengthinequality than total hip arthroplasty caused by other reasons. However, uniformtreatment standard is yet into being.3. Detailed preoperative assessments must be conducted to make limb balance plans.4. Different types of DDH dislocation require different strategies to balance the limbs.We should make individualized analyses and use individualized approaches.