Factors affecting aseptic loosening of 4750 total hip arthroplasties: multivariate survival analysis.
BACKGROUND
Total hip arthroplasty is a successful surgery, that fails at a rate of approximately 10% at ten years from surgery. Causes for failure are mainly aseptic loosening of one or both components partially due to wear of articular surfaces and partially to design. The present analysis aimed to identify risk factors and quantify their effects on aseptic failure.


METHODS
Multivariate survival analysis was applied to 4,750 primary total hip arthroplasties performed between 1995 and 2000.


RESULTS
The survival of the prosthesis is affected by gender, age, pathology, type of the prosthesis and skill of the. The worst conditions are male patients, younger than 40 years, affected by sequelae of congenital diseases, operated by a who performed less than 400 total hip artroplasty in the period. Furthermore, cemented cups and stems (less expensive) have a higher risk of failure compared with uncemented ones (more expensive).


CONCLUSIONS
The only variable that affects survival and that can be modified by is the type of prosthesis: a lower cost is associated to a higher risk. Results concerning the risk associated with cemented components are partially in disagreement with studies performed in countries where cemented prostheses are used more often than uncemented ones.
Bordini
Barbara
B
Laboratorio di Tecnologia Medica, Istituti Ortopedici Rizzoli, Bologna, Italy. bordini@tecno.ior.it
Stea
Susanna
S
De Clerico
Manuela
M
Strazzari
Sergio
S
Sasdelli
Antonio
A
Toni
Aldo
A
D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000706:statistics & numerical data*; D001843:Bone Cements; D004867:Equipment Design; D005260:Female; D006622:Hip Prosthesis / Q000191:economics; D006801:Humans; D007558:Italy; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D011475:Prosthesis Failure; D012189:Retrospective Studies; D012307:Risk Factors
D001843:Bone Cements