A simple technique to strengthen the initial and mid-term to long-term stability of the cup during total hip arthroplasty in developmental dysplasia of the hip

OBJECTIVES: To assess the effects of a technique of cup blocking screws combined with impaction bone grafting during total hip arthroplasty (THA) for patients with developmental dysplasia of the hip (DDH). METHODS: From August 2011 to July 2015, 53 patients (59 hips) with DDH in our hospital were treated with THA using the technique of cup blocking screws combined with impaction particulate bone grafting. These patients were prospectively followed, and the clinical and imaging results were collected. RESULTS: Harris hip score (HHS) was raised from 41.24 before surgery to 91.49 at the latest follow-up (p<0.001). Length discrepancy (LLD) was reduced from 28.97 mm before surgery to 6.08 mm after surgery (p<0.001). No loosening of the cup was detected at the last follow-up. The differences were insignificant in cup inclination and rate of cup coverage among the 3 groups of Crowe type II, type III, and type IV DDH (p>0.05). CONCLUSION: The technique of cup blocking screws combined with impaction particulate bone grafting is simple and reliable, and it not only simplifies the attainment of initial stability, but also strengthens the mid-term to long-term stability during THA in DDH.