Minimally Invassive Hip Surgery

Minimally invassive hip surgery at The Runnymede

Minimally Invasive Hip Surgery

 

Please replace with Less Invasive Hip Surgery

Inevitably, some soft tissue disruption occurs when a total joint replacement is performed.

Over the last 5 to 10 years much research has been done into reducing the amount of soft tissue disruption when performing total hip replacement.

The premise of minimally invasive surgery (MIS) is to minimise this soft tissue disruption both with the skin incision and the dissection of the deeper tissues.

There is no doubt that the initial pioneers, “overcooked” this principle and caused complications when striving for the smallest possible incision. This has now led to a change from minimally invasive surgery to less invasive surgery.

I often tell my patients that the incision needs to be big enough to do a proper operation but we aim to make it small enough to give the best possible cosmetic result.

This has the potential benefit of reducing intra-operative blood loss, improve speed of rehabilitation and recovery, and decrease hospital stay.

Minimally Invasive Surgery (MIS)

A number of different minimally invasive techniques exist in a total hip replacement. This is based on the number of incisions (one or two) or the anatomical approach to the joint (for example anterior, posterior or direct lateral).

Often minimally invasive joint surgery creates the potential for reduced visualisation and subsequently improper component placement.

It is fact however that the one factor that allows the implant to survive as long as possible, is when it they been placed in the correct position.

Use of intra-operative X-Ray and computer assisted surgery are being used to improve correct orientation of the implants.

The skin incision therefore can be small but needs to be adequate enough to allow for proper placements of the components. Perhaps we should really call it least invasive surgery rather than minimally invasive surgery. Please remove this sentence.

For the majority of patients the average length for a minimal incision hip replacement is 8-10 cm.

In addition, the use of new anaesthetic techniques developed concurrently with MIS surgery has improved the speed at which patient can be rehabilitated.

Not all patients are a candidate for MIS joint surgery. Hip resurfacing can not be done using MIS. (Please remove)

This 55 year old lady presents with osteoarthritis of the right hip. She had an uncemented total hip replacement through a minimally invasive approach. This is the incision at three months. The scar measures 8 cms. Scar size is not so important, the way the components have been placed is far more important!

Please remove the two photos on the left with the two photos below.

Information on MIS hip replacement Please remove this sentence

Avascular necrosis of the hip. (AVN)

Avascular necrosis (AVN) of the hip is not uncommon painful condition where there is a compromise to the blood supply of the femoral head. Ultimately, this may lead to the bone of the femoral head dying off leading to collapse of the femoral head and following that, relatively rapid onset of degenerative change (osteoarthritis) of the femoral head.

The most common causes of AVN of the femoral head are, trauma (dislocation of the hip or femoral neck fracture), the use of steroids, alcohol, rare clotting abnormalities, and in some cases no cause can be found.

The aim of the treatment of this condition is to catch it early, control the pain, and to prevent the collapse of the femoral head.

There have been number of techniques described, and all have various degrees of success.

Tablet treatment using bi-phosphonates and the use of anticoagulation has been trialled in the “pre-collapse” state of the femoral head with reasonable success.

The use of the procedure of core decompression is used most frequently. In those patients where the bone in the femoral head has not died off, and collapse has not happened the chances of success using this technique between 60-75%.

For more information on avascular necrosis of the femoral head of the hip please click the following link.

http://orthoinfo.aaos.org/topic.cfm?topic=a00216

Fig 1.

Fig 1. The most sensitive investigation for AVN is a MRI scan. The darker area on this T1 weighted image shows the area of compromised blood supply to the femoral head.

Fig 2.

Fig 2.

Fig 2. During the procedure of decompression the area of avascular necrosis is located with a guide wire using an image intensifier (X-Ray machine . The area is decompressed and as much of the avascular area of bone removed, as possible. A scaffold material is then injected to allow new bone to grow into the area and hopefully prevent collapse of the femoral head.

Fig 3.

Fig 3. This shows a case of avascular necrosis after having undergone core decompression and introduction of a scaffold. The initial x-ray is at six weeks followed by three months followed by one year. At one year, the scaffold has resorbed and has been substituted by bone and at this stage femoral head collapse has been prevented.