[Relationship between initial stability and infected loosening of total hip arthroplasty prosthesis].
OBJECTIVE
To investigate the relationship between the initial stability and infected loosening of the total hip arthroplasty (THA) prosthesis.


METHODS
From January 2000 to December 2008, 110 cases (110 hips) were treated with THA revision. Among them, 15 cases (15 hips) were confirmed infected loosening. There were 8 males and 7 females with an average age of 62 years (range 42-75 years). The infected signs were found from 6 months to 2 years after initial THA. All of them had Tsukayama type IV and late infection, including 6 cases of acetabular infected loosening (5 cases of one-stage and 1 case of two-stage acetabular revision), 7 cases of simple infected loosening of femoral prosthesis (4 cases of one-stage and 3 cases of two-stage femoral prosthesis revision), and 2 cases of joint capsule infection and sinus without prosthesis loosening (debridement and continuous irrigation).


RESULTS
All incisions healed by first intention. Fifteen patients were followed up for 12 to 36 months (average 24 months). In 13 cases of revision, postoperative X-ray films showed that femoral acetabular prostheses were in good position, and had no clinical and imaging infective signs of loosening. In 2 cases of joint capsule infection, sinus recurred 6 months postoperation without hip joint pain, the function of weight-bearing and walking of hip joint was normal. Harris score increased from preoperative average of 42 to postoperative average of 85; the results were excellent in 4 cases, good in 7 cases, and fair in 4 cases.


CONCLUSIONS
The infection of THA may occur in the whole joint, half-joint or just in joint capsule. The initial stability of the prosthesis would affect the long-term survival of the prosthesis. If the prosthesis initial stability is obtained, even if there are infective factors, infections would also be limited.
Sun
Yongqiang
Y
Department of Orthopaedics II, the 2nd Hospital Affiliated Henan College of Traditional Chinese Medicine, Zhengzhou Henan, 450002, P.R. China. joint99@126.com
Ai
Jinwei
J
Cao
Yujing
Y
Liu
Ruyin
R
Wang
Shangzeng
S
Wang
Xibin
X
D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation*; D005260:Female; D006622:Hip Prosthesis / Q000382:microbiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011475:Prosthesis Failure / Q000209:etiology*; D016459:Prosthesis-Related Infections / Q000150:complications*