Advertisement for orthosearch.org.uk
Orthopaedic Proceedings Logo

Receive monthly Table of Contents alerts from Orthopaedic Proceedings

Comprehensive article alerts can be set up and managed through your account settings

View my account settings

Visit Orthopaedic Proceedings at:

Loading...

Loading...

Full Access

TOTAL HIP ARTHROPLASTY: TREATMENT OF CHRONIC INSTABILITY USING A DOUBLE-MOBILITY CUP



Abstract

Purpose: Dislocation of total hip arthoplasties is a sad reality. The incidence of this complication is estimated from 0.6 to 8%. Dislocation can be a single event that never recurs, but half of all dislocations will reoccur again. We analysed outcome after treating chronically unstable total hip arthroplasties using a double-mobility cup.

Material and methods: Between 1990 and 2000, we treated 42 cases of recurrent dislocation of total hip arthroplasties. Five were immediate, 33 early, and four late; five dislocations on the average. The prosthesis was implanted via the posterolateral approach for 36 patients. Thirteen patients treated in our unit had already had surgical treatment for chronic instability: 1 trochanteoplasty, 8 bone blocks, 5 restraining cups. A standing AP view of the pelvis was obtained in all patients before surgery to analyse shortening (gluteus medius insufficiency), cup tilt and anteversion, and stem lateralisation. Likewise a CT scan was performed systematically to analyse stem and cup anteversion. No position anomaly was found in 17 patients; at least one anomaly was found in the others. All patients were reoperated via the posterolateral approach. A double-mobility cup was implanted systematically without changing the stem.

Results: Among the 42 patients, we had two with recurrent dislocation, one in a neurologic patient and one in a patient with major anomalies in the position of the femoral component that was not changed. The incidence of recurrent dislocation was thus 4.75%.

Discussion: The therapeutic method used here can be compared with other solutions (trochanteroplasty, anti-dislocation crescent, antidislocation bone block, bipolar replacement). The double-mobility cup is particularly interesting for high-risk patients: neck fracture, tumour surgery, neurological disease, antecedent non-prosthetic surgery (dearthrodesis prosthesis). We advocate revision surgery after three dislocations.

Conclusion: The double-mobility cup appears to be a valid therapeutic option, both for the treatment and prevention of chronic instability of total hip arthroplasty.

The abstracts were prepared by Pr. Jean-Pierre Courpied (General Secretary). Correspondence should be addressed to him at SOFCOT, 56 rue Boissonade, 75014 Paris, France