Total Hip Arthroplasty in Untreated Posterior Acetabular Wall Fracture

Background: Total hip arthroplasty (THA) in patients with chronic untreated fracture of the posterior acetabular wall represents a rare and challenging scenario for joint surgeons. There are many reports on THA following acetabular fractures treated by internal fixation; however, there are few previous reports on THA following missed posterior wall fracture. Objectives: In this study, a case series of patients with untreated posterior wall fracture of the acetabulum managed by cementless THA and superior placement of acetabular cup was presented. Materials and Methods: Seven patients (mean age of 42 years) with untreated posterior wall fracture of the acetabulum, presented to our institution with severe osteoarthritis 5 months after primary trauma (ranged 3.4 to 7.2). There were 5 pure posterior wall fractures and 2 posterior wall and column fractures. It was decided to put the cup in a little higher center rather than reconstruct the posterior wall. All cases were performed with the lateral approach in supine position. All patients were ambulated on the day after surgery with weight bearing as tolerated program. We did not apply hip precautions to these patients. Results: Acetabular implants were placed within 8 - 18 mm upward from the tear drop (upward distance average 14.4 mm). Postoperatively, the function of hip joints improved with HHS rising from 42.5 ± 6.42 to 88.3 ± 7.27 after one year, which was significantly different (T = 12.49, P < 0.0001, 95% confidence interval: -53.7872 to -37.8128). At the latest follow-up (mean: 45 months, ranged 39 - 52 months), radiographic assessment showed satisfactory cup position with bone ingrowth and no signs of loosening. Conclusions: Putting acetabular cup in a higher but more supportive bone offers a reliable and easier technique for reconstruction of acetabular posterior wall deficiencies. Further studies are needed to prove long-term outcomes of this method.