Extra-articular Blocking Technique to Resolve Severe Acetabular Bone Defect in Developmental Dysplasia of the Hip

Extra-articular blocking technique for acetabular bone defect reconstruction

The acetabular bone defect reconstruction is of great challenge in total hip arthroplasty (THA). Although several solutions such as autologous bone grafting, trabecular metal augment, or compromising techniques such as the medial protrusion, high inclination angle, and elevated hip center have been raised, their efficacy and reliability have not been fully substantiated. Traditional reconstruction methods may lead to bone resorption, aggravation of bone defects, unequal length of lower limbs, unbalance of hip-spine relationship, increased costs, and so on. Our team proved a new technique named extra-articular blocking to resolve this problem. The extra-articular blocking technique was a simple, economic and effective acetabular reconstructive method to resolve the massive acetabular bone defect in congenital (especially for developmental dysplasia of the hip, DDH), inflammatory, and osteolytic pathologies. This article organized as surgical technique, aims to report the surgical principle, indication, and procedure of using extra-articular blocking technique. With this technique, we have successfully solved the difficult problem of acetabular bone defect reconstruction. We found after 3 months of the surgery, there were fluoroscopic healing and remodeling. And there were no bone loss or graft absorption until the last follow-up as evidenced by radiographic observation. The survival rate of the acetabular component was 100%, no radiolucent line, changes in inclination and anteversion of the shell, as well as migration of the rotation center were identified.