RECURRENT DISLOCATION AFTER PRIMARY TOTAL HIP REPLACEMENT

Abstract

Far too many cases of instability and recurrent dislocation occur after primary total hip replacement. The motivation for this paper came from yet another three cases of recurrent dislocation on our theatre list in a single month (March 2006). All three were recurrent dislocations after primary hip replacements. Since these were not three isolated cases we realised that there is an urgent need to improve the situation. In all three cases surgical or implant factors were responsible.

We take a fresh look at the causes; which are implant, surgeon and patient related. Of these only patient related issues cannot always be corrected. The design of a stable implant is discussed and revolves around head size, head neck ratio and cup depth. The surgeons’ contribution can be equally important and controllable – it embodies correct peri-articular soft tissue tension, orientation of components and patient selection. Finally, patient factors are neuromuscular, anatomical and patient compliance. In this respect some unresolved factors should be identified pre-operatively.

Especially for the occasional hip surgeon this is an extremely important issue. The recurrent dislocation results in extremely poor quality of life, often leading to revision surgery. These aged patients usually suffer multiple inherent risks and massive financial losses. Above all we believe that the great majority of these dislocations can be prevented by simply keeping to the clear and well proven principles of stability in total hip replacement.