The Effect Of The Trabecular Metal Augments For Reconstructing The Paprosky Type ? Acetabular Defects

Objective:To assess the clinical and radiological outcome of the trabecular metal augments for reconstructing the Paprosky type ? acetabular defects in revision hip arthroplasty.Methods:From June 2015 to April 2017,the clinical date of 18 patients(18 hips)treated by trabecular metal augments in the treatment of the Paprosky type ? acetabular defects were analyzed retrospectively.There were 8 males and 10 females,aged 48-78 years,with an average age of 64.1 years.Paprosky standard classification was used to classify acetabular defects,11 cases of type 3A and 7 cases of type 3B.The Harris score of hip joint,the change of rotation center of hip joint,the length of both lower limbs and the bone ingrowth were recorded before and after operation,and the related complications were followed up.Results:All the patients were followed up for 2.5 to 4 years(3.2 years on the average).The Harris score improved from 31.6±8.8 preoperatively to 83.7±8.4 at the final follow-up(P<0.001),according to Harris hip joint function score standard,8 cases were excellent,5 cases were good and 5 cases were fair at the last follow-up.Centre of rotation of hip joint corrected from 39.2±7.2 mm preoperatively to 18.8±7.3 mm postoperatively above the interteardrop line(P<0.001).The leg-length discrepancy was 22.9±13.6 mm preoperatively and 3.2±7.7 mm postoperatively(P<0.001).During follow-up,no cases showed periacetabular osteolysis,and the bone in-growth between host bone-cup interface and the host bone-augments interface were good.No complications such as prosthesis dislocation,wound infection,periprosthetic fracture,deep venous thrombosis were found.Conclusion:The trabecular metal augments can increase the surface area of prosthesis,optimize the contact area between the trabecular metal and host bone,reserve as much host bone as possible,and effectively fill the serious acetabular bone defect.The trabecular metal augments for reconstructing the Paprosky type ? acetabular defects in revision hip arthroplasty has good initial stability,early bone in-growth and short-term effects.However,long term study is required for better evaluation.