Clinical and radiographic evaluations of titanium trabecular metal components manufactured by 3D printing for primary total hip arthroplasty: a 5-year follow-up / 中华创伤骨科杂志

ABSTRACT

Objective To explore the mid-term efficacy of porous titanium trabecular metal ( TTM ) components manufactured by 3D printing for primary total hip arthroplasty ( THA ). Methods Enrolled for this prospective clinical trial were 19 patients ( 20 hips ) who were to receive primary THA from May 2012 to June 2013 at Department of Orthopaedics and Traumatology, Puai Hospital. Of them, 9 patients ( 10 hips) used 3D printing porous TTM for acetabular prosthesis in primary THA while the other 10 patients ( 10 hips ) used Pinnacle acetabular prosthesis. At 5 years after operation, clinical and radiographic evaluations were conducted to assess acetabular component stability, osseointegration in the acetabulum-bone interface, and osteolysis incidence. Harris scores were used to assess the hip functions. Results The follow-up duration for all the patients averaged 5 years. By the Harris scores, 8 cases were excellent and 2 good in the TTM group while 9 excellent and one good in the Pinnacle group. The Harris scores were significantly improved from preoperative 48.2+5.5 to 92.8+3.1 at 5 years after operation in the TTM group and significantly from 46.5 ± 8.7 to 94.6 ± 2.9 in the Pinnacle group ( P ＜0.05 ). There were no significant differences regarding the preoperative Harris scores and those 5 years after operation between the 2 groups ( P ＞ 0.05 ) . Radio-graphic evaluation showed stable acetabular components, fine osseointegration, and no implant loosening or osteolysis. Two hips in the TTM group had a postoperative radiolucent line which disappeared 6 months later. The 5-year survival rate of the acetabular components was 100% for both groups, taking prosthetic loosening or revision as the end point. Conclusion The 3D printing TTM has shown excellent mid-term efficacy but its long-term efficacy needs further follow-up study.