Acetabular reconstruction for primary and revision total hip arthroplasty using Kerboull-type acetabular reinforcement devices-case-control study with factors related to poor outcomes of surgery.

Kerboull-type acetabular support rings (KT) and allogenic bone graft were used for severe periacetabular bone loss with primary and revision total hip arthroplasty (THA). The purpose of this case-control study is to evaluate the risk factors related to poor outcomes of surgery. Sixty patients underwent primary THA and revision THA using allogenic bone graft with KT for large acetabular deficiency. These patients were retrospectively evaluated postoperatively and followed-up by radiograph. The minimum follow-up period was 4 years and averaged 7 years. A radiological failure was defined by the following criteria: 1) substantial migration defined as change in the angle of inclination of more than 5 degrees or migration of more than 5 mm, 2) breakage of the screw or device, 3) acetabular revision due to aseptic loosening. Expected risk factors were defined as female, age > 75 years, body mass index (BMI)>25%, medical history of hypertension, renal failure, liver steatosis, diabetes, hyperlipidemia, cardiac infarction, smoking, American Academy of Orthopedic Surgery (AAOS) classification III or IV, bleeding>500 mL, time of surgery >3 hours, high hip center-type KT, inclination of KT >45 degrees, screw angle >25 degrees, morselized bone graft, Kawanabe's classification stage 3 or 4 and revision surgery. Nineteen hips (31.6%) revealed radiological failure according to our criteria, and revision THA was performed in 2 hips (3.3%). In the statistical analysis, morselized bone graft and high hip center-type KT were identified as factors of poor outcomes of surgery.