[A modified porous tantalum implant technology for osteonecrosis of the femoral head: survival and prognostic evaluations of conversion into total hip arthroplasty].
OBJECTIVE
To assess the survival and prognostic significance of various demographic and radiographic parameters for conversion into total hip arthroplasty after treatment with a modified porous tantalum implant technology for early and intermediate stages of osteonecrosis of the femoral head (ONFH).


METHODS
This study included 45 patients (59 hips) with Steinberg Stage I-IV A ONFH undergoing progressively core decompression, impaction bone grafting of 5 mm-composite bone filling material and inserting of a porous tantalum implant. Weight-bearing was forbidden within the first 3 months after implants.


RESULTS
A total of 57 hips (44 patients) were available during a mean follow-up period of 44.8 (11-62) months. Their mean age was 43 (21-70) years. The mean Harris hip score significantly improved from 59.93 ± 2.80 preoperative to 77.84 ± 2.95 at the last follow-up (P < 0.001). Overall, 11 hips (19.30%) were converted into total hip arthroplasty. The overall survival rate was 72.49% at 60 months postoperatively. The Cox proportional hazard model revealed that bone marrow edema was an independent prognostic factor related with a conversion into total hip arthroplasty.


CONCLUSIONS
Higher survival rates may be obtained from modified tantalum implant technology for early and intermediate stages of ONFH. And prognosis was poor for patients of ONFH with bone marrow edema.
Department of Orthopedic Surgery, PLA No. 307 Hospital, Beijing 100071, China.
Yaosheng
Y
Liu
Email: 15810069346@qq.com.
Shubin
S
Liu
Shiguo
S
Zhou
Xiuyun
X
Su
Cheng
C
Wang
Yuncen
Y
Cao
Weihao
W
Jiang
Qiu
Q
Cui
Lei
L
Wang
D019644:Arthroplasty, Replacement, Hip; D016025:Bone Transplantation; D019299:Decompression, Surgical; D006801:Humans; D010020:Osteonecrosis; D016062:Porosity; D011184:Postoperative Period; D011379:Prognosis; D019736:Prostheses and Implants; D013635:Tantalum
D013635:Tantalum