TOTAL HIP REPLACEMENT
Modern total hip replacement has it roots in the pioneering work of Sir John Charnley in the 1960’s.
His work bought about the age of modern cemented hip replacement with the Charnley prosthesis.
During the following decade other cemented hip replacements would emerge onto the UK market from centers such as Exeter and Stanmore.
During the 1980’s hip replacements which were Uncemented became popular.
These were coated with substances which allowed the patients own bone to grow on to the hip replacement forming a biological bond between the patient and their hip replacement.
Today both types of hip replacement continue to be utilised.
The process of total hip replacement involves and incision over the upper outer thigh.
Typically this is one hands breadth centred over the bony prominence on the upper aspect of the thigh.
After incising the skin and fat the surgeon will reach a tough band of tissue known as fascia.
This is also incised. Following this the surgeon is presented with the thigh bone with all its muscles attached to it.
A number of surgical approaches can be used to gain access to the hip joint from this point.
There are a number of arguments around which approach is used but typically the approach used will come down to that familiar to the surgeon from his training.
We utilise a “posterior” approach.
During this an approach is made to the hip through its posterior aspect releasing very few muscles as well as the posterior portion of the capsule (lining) of the hip joint.
This approach is associated with a lower incidence of the patient having a limp following the operation.
It also allows direct visualization of the main nerve to the leg, the Sciatic nerve, allowing its protection during surgery.
After opening the hip joint the hip can be dislocated and the top of the thigh bone, the head and neck, exposed fully.
This is then removed using a medical saw. This process exposes the bony socket within the pelvis.
This socket is then prepared to accept a press fit socket which is impacted into place.
Following this the thigh bone is prepared to take a press fit coated stem component using a series of broaches.
A process of trialing can take place to check the patients’ leg lengths are equalized and that the trial components are “stable” in the implanted cup component.
Once the surgeon has established that the position of the components will result in a stable hip replacement the definitive stem and head components can be implanted.
Following this, final checks can be made on leg length and the components washed thoroughly.
At this point the wound and deep tissues are injected with a combination of local anaesthetic and adrenalin to supplement the post operative analgesia and to help reduce bleeding.
A drain may be inserted to collect blood that would otherwise collect in the deep tissues but increasingly these are only used in the most complicated cases.
The various layers of soft tissue are then closed using sutures with a final layer of clips in the skin.
Following surgery patients are supplied with a supply of pain killers via a pump driven syringe driver from which they are able to administer small doses of pain killer a pre-set intervals.
The drain will remain in place only until the next morning if used and patients usually begin physiotherapy at that stage initially walking with the aid of a frame and progressing to crutches.
The following picture shows typical scarring 3 days after surgery.
A typical hospital stay is 2-4 days but this will vary between individuals according to age and personal circumstances.
There are number of potential complications of hip replacement which are covered on this site (click here to link).
Modern hip replacement offers a fantastic relief of the disabling symptoms of hip arthritis.
Patient’s lives are transformed and their symptoms removed.
In recent years advances in hip replacement design, technology of metal (tribology), engineering techniques as well as surgical techniques have made hip replacement possible for increasingly younger adults.
The use of ceramics and modern designs of hip replacement will potentially revolutionize hip replacement surgery and reduce suffering and the possible need for revision hip surgery in the future.