Early outcomes of reconstruction of Paprosky Ⅲ acetabular bone defects using tantalum trabecular metal cup combined with tantalum augment / 中华骨科杂志

ABSTRACT

Objective To investigate the early outcomes of reconstruction of severe acetabular bone defects by the use of tantalum trabecular metal cup combined with tantalum augment in total hip replacement.Methods From April 2014 to December 2015,23 patients (24 hips) underwent total hip arthroplasty by the use of tantalum trabecular metal cups combined with tantalum augments.There were 11 males (12 hips) and 12 females (12 hips),with the average age 54 years (range,38-65 years).We tried to reconstruct an annular support for the cup.If an annular support cannot be reconstructed,the cup obtains primary stability based on the three point fixation rationale.Flexible placing of the TM cup combined with the augments helped reconstruction of the socket ring or supporting points,thus achieving rigid primary stability of the cup and restoring center of rotation.Harris hip score and Western Ontario and McMaster Universities (WOMAC) osteoarthritis index score were recorded.Any severe intraoperative complications including vascular or nerve injury and severe postoperative complications such as periprosthetic joint infection,dislocation or periprosthetic fracture were reported.The vertical position of the center of rotation from the interteardrop line and the horizontal position of the center of rotation from the teardrop were measured and analyzed.Results The average follow-up duration was 16 months (range,7-28 months).The mean Harris hip score was 35.3±12.1 preoperatively and 82.7±8.3 postoperatively (t=-16.991,P＜0.001).The mean WOMAC score was 39.1 ±24.0 preoperatively and 87.2± 11.4 postoperatively (t=-7.671,P＜ 0.001).The average vertical location of the center of rotation was 44.02± 11.65 mm preoperatively and 22.96±8.24 mm postoperatively.All the tantalum cups and augments were stable.There was no periprosthetic joint infection,dislocation,nerve injury or periprosthetic fracture.Conclusion Reconstruction of Paprosky Ⅲ acetabular bone defects by the use of tantalum trabecular metal cup combined with tantalum augment can achieve good primary stability and restore the center of rotation with almost normal hip biomechanics.The short-term outcomes are satisfied.