Tantalum trabecular metal cup with trabecular metal augments for Paprosky type Ⅱ and type Ⅲ acetabular defects in revision hip arthroplasty / 中华骨科杂志

ABSTRACT

Objective To investigatc thc short-term clinical and radiographic outcomes of tantalum trabecular metal (TM) components associated with TM augments for Paprosky type Ⅱ and type Ⅲ acetabular defects in revision hip arthroplasty.Methods From June 2014 to April 2016,seventeen patients with aseptic loosening underwent revision total hip arthroplasty for Paprosky type Ⅱ or type Ⅲ acetabular defects with TM revision acetabular cups and TM augments.The subjects consisted of 5 males and 12 females with mean age of 56.6 years (range 30-75).Acetabular bony defects were Paprosky type Ⅱ A in 4 hips,Ⅱ B in 3 hips,Ⅲ A in 8 and Ⅲ B in 2 hips.The whole hip revision was performed in 13 hips and acetabular reconstruction in 4 hips.Preand post-operative functional outcomes were accessed by the Harris Hip Score.The vertical and horizontal position of the rotation center from the intertear drop line were measured and analyzed.Complications were recorded during the follow-up.Radiographic examination was performed after operation immediately by X-ray.The recent X-ray was conducted to assess bone ingrowths at the cup-bone or augments-bone interface,radiolucent lines and implant migration.Results All of the patients were followed-up for an average of 23 months (range 11-33 months).There was no infection,dislocation or periprosthetic fracture complications at the last followed-up.The Harris Hip Score was improved from 45.8±3.4 pre-operatively to 79.2±7.5 post-operatively (t=-16.8,P=0.00).The mean vertical distance of the center of rotation was 32.1±4.3 mm preoperatively and 14.5±2.3 mm postoperatively (t=14.8,P=0.00).The mean horizontal distance of the center of rotation was 33.6±6.1 mm preoperatively and 27.8±3.2 mm postoperatively (t=3.5,P=0.00).More than 3 radiographic signs of osseointegration were observed in 11 hips.No progressive radiolucent lines or component migration was observed.All the TM components were well-fixed at last follow-up.Conclusion Using tantalum TM cups with TM augments in revision hip arthroplasty could be regarded as an effective management for Paprosky type Ⅱ and type Ⅲ acetabular defects.This technology can avoid using over-large cup,provide reliable primary stability,restore the center of rotation with almost normal hip biomechanics and improve the functional outcome.