When a patient has been recommended for a total hip arthroplasty (THA, also known as a total hip replacement) one of the most common complications in the years following the surgery is hip dislocation. The NHS reports that this happens in around 10% of cases. This is a frustrating complication for all involved and it is not always immediately obvious what the cause of dislocation is.
Hip replacement dislocation: the patient has had a lumbar fusion
A lumbar fusion is an operation designed to help patients who have spinal problems, specifically it fuses together two or more of the tiny bones in the spine, the vertebrae, so that they work together as one fused bone.
The aim of this is to stop the movement between these bones in cases where their natural alignment is causing the patient pain and impaired mobility. In a huge study conducted using patient data gathered between 2005 and 2012, the Bone and Joint Journal reports “patients with a previous history of lumbar spinal fusion have a significantly higher rate of dislocation of their THA than age- and gender-matched patients without a lumbar spinal fusion.”
More research is required to establish what can be done to reduce the risk of dislocation following THA in patients who require or have had a lumbar fusion. Patients requiring either surgery will no doubt be in serious discomfort, with limited or no other options to fix the problem, other than via these methods.
Hip replacement dislocation: the patient has decreased spinopelvic motion
According to a report published recently in the Journal of Bone and Joint Surgery, dislocation following THA is also much more common in patients who have a spinopelvic imbalance – in layman’s terms, the tilt of the pelvis and the angle of the spine are misaligned, causing unnatural wear and tear on hip joints. This issue is exacerbated if coupled with either cup malposition or soft-tissue abnormalities.
The results came from a 20-patient study where all had suffered dislocation following a THA and, as such, data was examined to understand what factors could have caused the joint to dislocate.
Looking to understand hip replacement dislocation more clearly
Whatever the cause of the dislocation, hip replacement surgeons will welcome more research into this issue as when it does occur it will often require revision surgery (surgical intervention to replace or fix the joint again). Typically, dislocations of this nature occur between 10 and 15 years after the initial operation, but in rare cases, this can happen very soon after surgery. If you have undergone a THA and have any concerns, then consulting your hip surgeon quickly will ensure you are in the best hands to assess the problem and to agree the most suitable course of action.
Revision hip surgery is much more challenging than the initial procedure; Mr Simon Bridle combines surgical expertise with clinical experience and specialist training to deal with complex revision cases and has performed many of these procedures over the years.