[Risk factors associated with heterotopic ossifications in primary total hip arthroplasty].
OBJECTIVE
The purpose of this study was to determine the important predisposing factors associated with heterotopic ossifications (HO) after total hip arthroplasty.


METHODS
589 patients were examined 6 months after primary total hip arthroplasty with regard to periarticular ossifications. Several predetermining factors were evaluated using the hospitalization records and preoperative X-ray examination.


RESULTS
A significantly increased frequency of heterotopic ossifications was found for male gender, patients with very high body mass index (BMI), low preoperative range of motion (ROM), long duration of operation and large preexistent osteophytes (p < 0.05). Only one out of the one hundred patients with an BMI < 22.6 developed severe HO (Brooker III). Out of the one hundred patients with the best preoperative ROM (> or = 140 degrees ) only one case developed severe ossifications (Brooker III). There was no correlation with the use of acrylic bone cement or the patient's age. The frequency of HO was significantly reduced both as well by nonsteroidal antiinflammatory drugs as from postoperative radiation prophylaxis.


CONCLUSIONS
In patients undergoing total hip arthroplasty with low preoperative ROM in the hip joint, large osteophytes and a very high BMI an efficient prophylaxis against HO is of great importance.
Handel
M
M
Orthopädische Universitätsklinik, Lehrstuhl für Orthopädie der Universität Regensburg, Bad Abbach. m.handel@rheuma-ortho-zentrum.de.
Brettschneider
J
J
Köck
F X
FX
Anders
S
S
Perlick
L
L
Sell
S
S
D019644:Arthroplasty, Replacement, Hip / Q000706:statistics & numerical data*; D015992:Body Mass Index; D015984:Causality; D015897:Comorbidity; D005260:Female; D005858:Germany / Q000453:epidemiology; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery*; D006622:Hip Prosthesis / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009999:Ossification, Heterotopic / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000453:epidemiology*; D011475:Prosthesis Failure; D011859:Radiography; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D017678:Sex Distribution; D016896:Treatment Outcome