Hip Review Clinic
Hip Revision Surgery
Dislocation of a hip replacement means the ball has come all the way out of the socket. When the hip pops out it is usually very painful and requires a trip to hospital for the ball to be replaced in the socket.
Partial displacement, called subluxation, it is difficult to diagnosis as there are other causes of "clicking and clunking" around the hip.
The risk of dislocation is highest in the early post-operative period before the soft tissues have healed. After about 6-8 weeks the muscles and fibrous tissues around the hip offer more support and resist movements that may lever the ball out of the socket. A single dislocation during this healing process does not always lead to long term problems.
However, a small number of hip replacements go on to recurrent dislocate. The risk factors and causes of recurrent dislocation have been extensively studied. For any one patient this problem is usually multi-factorial.
Treatment of first time dislocationDislocation in the first few weeks is usually due to poor muscle tension. The x-rays of the hip joint before the dislocation and after it has been replaced should be carefully studied to exclude component malposition, implant migration and implant disassembly. A CT scan may be useful to assess cup abduction and anteversion.
If the implant appears well fixed and well positioned it is unlikely that the hip will go on to recurrent dislocation [Prognosis of dislocation after total hip arthroplasty. Joshi A, Lee CM, Markovic L, Vlatis G, Murphy JCM. J Arthroplasty 13:17, 1998 ]. A period of extra-careful rehabilitation while the soft tissues recover is all that is usually required. For patients who struggle to control the position of the leg a brace may be useful to prevent further stretching of the soft tissues.
A single early dislocation is unlikely to significantly diminish the overall outcome [Functional Outcomes Following NonRecurrent Dislocation of Primary Total Hip Arthroplasty. M.E. Forsythe, S.L. Whitehouse, J. Dick MD, R. Crawford. J Arthroplasty. 2007 Feb;22(2):227-30. http://eprints.qut.edu.au/5589/1/5589_1.pdf].
Treatment of recurrent dislocationRecurrent dislocation has a dramatic effect, reducing confidence and in some cases patients become house bound. When a period of protected movement has failed then further surgery is recommended.
Any revision surgery requires careful planning and access to a wide range of implants and techniques. Depending upon the underlying cause of recurrent dislocation a variety of options are available to stabilise the hip. These are all major operations requiring 6-9 months of recovery.