Total hip replacement (THR) is a treatment for hip arthritis, and involves replacing the damaged hip joint with an artificial one (prosthesis).
THR is one of the most effective operations performed today, with the majority of patients achieving excellent pain relief. Current research shows that 85-90% of hip replacements last at least 15 years.
Hip replacements can be made of differing materials eg stainless steel, titanium, chrome-cobalt; can be fixed into the bone with either bone cement or be uncemented; and can have different bearing surfaces (the parts that move).
The bearing surface is of particular importance, as the debris cause by friction varies from material to material, and also varies in its effects on the bone. The combinations can be either metal-metal, metal-plastic (polyethylene), ceramic-ceramic and ceramic-plastic.
Due to concerns about the long-term effects of metal debris, Dr Shooter does not use metal-metal bearing surfaces, and so does not perform hip resurfacing.
It is important to remember that the father of modern hip arthroplasty surgery, Mr John Charnley, a UK surgeon, started doing THR’s around forty years ago. He used cemented stainless steel implants with a metal-plastic bearing surface, and his long-term results rival anything achieved today. Technological advances should always be taken in to account, but the goals of the individual patient are always paramount.
How the surgery is done
There are number of different ways to actually do the surgery ie the approach. Currently there are three main groups, in layman’s terms – from the back (posterior approach); from the side (anterolateral or Hardinge’s approach); or from the front (many different variations on “anterior”).
Why so many different ways? It reflects the surgeon’s own philosophy. Traditionally it has been thought a Harding approach offers more stability at the cost of function; the posterior approach was the opposite. Current research would suggest that if the approach is well done by an experienced surgeon, the results, for both stability (risk of dislocation) and function, are basically the same for both of these approaches.
The anterior approach is very different. This traditionally has not been used for hip replacements for a number of reasons. The proponents will tell you that it is much gentler on the muscles, and enables you to get back to work much more quickly. Is this a good thing? Personally, I would say no. Your hip replacement is a long-term investment you are making in your health – and no matter how “muscle-sparing” the approach claims to be, your muscles need a good period of time to recover before you get back to “normal”. It also has around a 100-case learning curve . . . which means the first 100 cases are not going to be crash hot. I have revised a number of these types of hip replacements, and mostly the errors are beginners mistakes that have occurred because the surgeon can’t see what they need to do, to put the components in correctly.
Recovery from Hip Replacement Surgery
Hip replacement may be performed using general anaesthetic (put to sleep), regional anaesthetic (epidural or spinal nerve blocks), or a combination of these techniques. Your anaesthetist will make recommendations about which technique best suits you.
You can place your whole body weight onto the hip and walk with assistance immediately after surgery. Hospital stay is usually 2-4 days. Crutches may be used for comfort a few weeks after the procedure and can be discarded when you are confident. Some people like to use a single crutch for a few weeks longer. Depending on your occupation, you will require 2-6 weeks off work. You are unable to drive for 4 weeks but can be driven as a passenger. If you are a commercial driver or drive as part of your job, you may require a safety assessment by an occupational therapist prior to recommencing work.
Hip replacement surgery is very safe, and serious complications are uncommon. Serious wound infection occurs in less than 1% and dislocation in approximately 2% of patients treated with hip replacement. Clots can form in the veins of the leg (deep venous thrombosis 'DVT'), which on rare occasions may dislodge and travel to the lungs causing breathing difficulty. Many patients with hip arthritis have a short leg on the effected side, which is corrected during surgery. Occasionally it is not possible to make the leg lengths equal (within 5mm), and the operated leg is made longer or shorter.