Hip Abductor Reconstruction Surgery
When a hip abductor tendon tears it usually cannot repair itself. Muscles can be compared to a tethered hot air balloon – in the fact that once the tether – or in this case the tendon, is cut, the balloon or the muscle will move away from its attachment. There is no way for the muscles to stretch back down to where they originally where.
Most commonly Mr Stott sees patients for surgery that have had lateral hip pain for some time, and the hip abductor tendons have ruptured. Sometimes these hip abductor tears can be a result of hip replacement surgery.
One of the most common ways of doing hip replacements world-wide is to cut through the hip abductor muscles (known as either the lateral or Hardinge or anterolateral approach). This used to be the safest method of doing a hip replacement. In this approach, the muscles are sewn back onto the bone afterwards. Sometimes this repair can fail. Patients who have a persistent limp after hip replacement surgery frequently have this problem.
Rarely nerves can be damaged in hip replacement surgery. Nerve damage results in muscles that no longer work, and is much more difficult to treat. Now muscles have to be transferred to replace the function of the damaged muscle.
An operation can be performed to repair the tendon. An incision is made in the side of your leg, over the bony prominence of your hip (trochanter). This incision varies in length, depending on what the surgeon has to do. Rarely the tear is small enough that the tendon can be directly sutured back to the bone, using special bone anchors. If the tendon does not have to be pulled down onto the bone this procedure often works. However, frequently there is a gap where the tendon has pulled off the bone. Repairing this directly onto the bone is usually unsuccessful in the long term, as the tendon and muscle will have to be stretched to pull it down. This often fails because all of the capillaries in the tendon are blocked by stretching the muscle. In Mr Stotts experience, patients often report that it works for a little time, then the tendon pulls off again
If there is a gap between the tendon and the bone, a ‘graft’ has to be used. People have tried different ways of repairing these tendons, with varying degrees of success. You can use an artificial plastic ligament to support the tendon, whilst it heals. This produces little inflammation around the tendon, but the plastic never dissolves, and can provoke an intense scar reaction. People have used grafts made from porcine pericardium (the tough tissue around a pig’s heart) however this is not very strong and often fails.
Over the last 10 years, hip surgeons have been using a graft harvested from a donated human Achilles tendon. Mr Stott invented this particular technique of hip muscle reconstruction. These grafts usually come from America. The donor is extensively tested for diseases such as hepatitis and HIV. The graft is surgically harvested and then thoroughly cleaned and sterilised. The surgeon will attach it to you bone – usually by means of two small screws, and then weave the tendon into your own tendon and muscle. Unlike organ transplants, you will not have to take any anti-rejection medication.
The graft provides 2 main functions
It acts as a strap, to take your weight while your own tendon heals
It provides a scaffolding, for your own cells to regrow tendon onto the bone.
The donor tendon will eventually disappear, leaving new tendon in its place. You will not need to take any anti-rejection medication for this operation.
The donor tendon may eventually snap if no healing occurs, so you have to look after it during this period. Most surgeons recommend at least 6 weeks putting very little weight through the hip, to protect the donor tendon. You will need to use crutches or a frame to walk. It takes up to 18 months for the repair to fully heal and full rehabilitation. In most cases, the repair is strong enough to take your full weight by 6 weeks.
Results of abductor reconstruction
The results depend on how much wasting of the muscle there was before the surgery. Mr Stott has reconstructed these muscles on people who have had tears for up to 8 years. These patients have made some improvement, but always have a limp. Everyone who has this surgery so far has improved, but the amount of improvement varies from patient to patient. The sooner the surgical reconstruction to the tear, the better the results seem to be. We have had one patient return to skiing following surgery, when they were on two crutches pre-operatively.
Risks of Abductor Reconstruction surgery
Pain. Sometimes these muscles have not been used for a long time, and it can be painful getting them to work again
Limp. The end result depends on how much working muscle you have left. If the muscle is repaired within a month or so, then the function will be nearly normal.The tendon can snap or re-tear even if it is fixed.
Infection. Most operations have an infection risk.The tendon grafts are thoroughly cleaned and tested for infections such as HIV and Hepatitis.These tendons have no blood supply of their own when they are put in, and are at risk of infection
Tissue reaction. We have seen several patients develop an inflammatory reaction to either the tendon, or some of the detergents that were used in the processing of the tendon.This used to be more common with previous generations of the graft.This can cause pain and swelling
Standard operative risks- thrombo-embolism (including Deep Venous Thrombosis or Pulmonary Embolism), numbness around scar and general anaesthetic risks
Failure. Whilst it would be extremely unusal for a grafted tendon to tear, sometimes the muscle is too damaged to work properly again.