[Risk factors that have influence on acetabular erosion after a hip hemiarthroplasty in the treatment of subcapital fractures].

Objective: To determine the factors that influence in the erosion to acetabular in patients with later hemiprosthesis to a fracture of hip with a survival greater to 1 year.

Material And Methods: We made retrospective, comparative, descriptive and observational study, in patients who were used hemiarthroplasty for fracture of hip between January of 1997 and January of 2003. We obtained two groups of patients, those that had not undergone erosion and those that had erosion greater to 3 mm looked for similar characteristics, like age, pre passable cane or physical activity, overweight, sex, concomitances disease, degree of osteoporosis, function to cardiopulmonar, survival, size of prosthesis. We compared both groups to know if specific parameters in relation to factors existed that influenced in the erosion to acetabular. With one it would mean of p < 0.02.

Results: Three hundred and twelve patients took part themselves. Seventy one patients did not fulfill the inclusion criteria. We observed, in patients of smaller age with greater degree of function to cardiopulmonar, without concomitances diseases, independent march, greater survival and overweight, greater erosion after a year or but of patients (p < 0.02). Sex, the osteoporosis and size of prosthesis did not influence for erosion risk since the findings were very similar in both studied groups (p < 0.02).

Conclusions: The patients who had one better function before and after the surgery, with similar characteristics within the training group, had greater risk of developing erosion to acetabular, reason why the positioning of a total prosthesis is but recommendable to avoid complications in the long term.