[Predictive factors of aseptic loosening of cemented total hip prostheses]

Aseptic loosening is the main long-term complication and indicates total hip replacement failure. There are many and often intricate causes for aseptic loosening. Incorrect placement of the implants is the most incriminated factor. Other patient and implant related factors may also predispose to loosening but to various degrees.

We conducted a retrospective study of 64 cases with aseptic loosening of total hip prosthesis to individuate patient, implant type and surgical technique related factors leading to aseptic loosening and to provide recommendations to minimize this risk.

This was an analytic retrospective study of 64 cases with aseptic loosening. The classification is that used by the French Society of Orthopedic Surgery and Traumatology. The average age of the patients at the time of the first arthroplasty was 40 years, 62 years at the time of loosening. Charnley stem was implanted in 55 cases, Muller stem in 9 cases. Acetabular component was well positioned in 69% of cases with an average inclination of 47.8 °. The stems were canal-filling in 86% of cases with Grade A cementation in 60% of cases. The mean time for loosening onset was 12 years. 72% of the prostheses had a survival longer than 10 years. Statistical analysis of the results identified risk factors leading to loosening, such as: age, body mass index, level of activity, cup inclination, femoral offset and cementation quality.

A significant reduction in aseptic loosening of total hip prostheses may only be achieved by a more rigorous selection of patients, a greater security in the technical act and a better choice of the implant to be placed.