Where St. Louis Eats

Osteoarthritis (OA) is the commonest joint degeneration condition in the world, resulting in huge amounts of pain and suffering, work loss, expense and disability. Ageing of western developed populations, soon to be followed by some developing countries such as China, will place an increasing burden on medical services as the occurrence of OA rises steadily with age. There will be an increasing need to provide medical and physiotherapy treatment for OA over the next 50 years and for many thousands of people this will involve joint replacement.

Medical interventions can be rated on a scale which calculates the improvement in quality of life which results and here hip replacement comes out top of all treatments. The 1960s saw its development into a standard treatment for hip arthritis but the 21st century has seen the technique evolve into a complex and predictable approach to many hip conditions, with excellent fifteen year plus results. Once conservative treatments have been exhausted due to a worsening joint then joint replacement becomes the standard choice.

Total hip replacement involves removal of the arthritic joint surfaces and their replacement with metal and plastic components. The top of the femur, the ball of the hip joint, is removed and the socket is reamed out to make it bigger to accept the new part. Cement is pressurized into the bony areas and a steel alloy femoral component with a ball and stem is inserted down the femur and a plastic cup of ultra high density polyethylene into the socket. The metal-plastic interface allows very low friction and wear, ensuring a long life for the joint.

Post-operative physiotherapy consists of reviewing the operation note and the medical observations, assessing the patient and instructing them in breathing and leg exercises. The physio assesses the sensibility and muscle power in the legs to exclude problems such as nerve injury, although an epidural can cause temporary loss of feeling and power in the lower body and delay mobilisation. The next physio job is to get the patient up out of the bed with an assistant, stand and walk them as appropriate with elbow crutches or a frame, taking account of the necessary precautions to avoid dislocation.

The patient continues with buttock, hip flexion, quadriceps and foot exercises regularly to encourage normal limb muscle function and help circulation. They take regular analgesia to reduce pain and assist in their ability to mobilise. Once safe they can mobilise independently at least three times a day to have a walk, go to the toilet and wash and dress. Sitting is encouraged as long as the chair is not low and they are not permitted to put their legs up when sitting.

A good gait pattern is important in restoring normal walking function, ranges of movement and muscle power and balance. Initial gait taught by physiotherapists is typically the “step to gait”, the walking aids moving forward first followed by the operated leg and then the unaffected leg steps up to the other. This is a slow but stable gait pattern and good for the initial stages. Patients progress quickly to the “step through gait” where the unaffected leg moves past the operated one, and eventually to an advanced gait where the crutches are moved forward at the same time as the operated leg. This pattern is very close to normal walking with a pair of crutches attached.

Six weeks or so after the operation the patient will have a good gait, have reasonable muscle power and be able to do most functional activities such as a walk, climb stairs and ride in a car. They may then move on to a stick if stability or balance is difficult or the person is very old. Patients can now return to normal activities but need to maintain the hip precautions: Avoid crossing the legs in sitting. Don’t stand on the affected leg and rotate. Don’t flex the hip suddenly or above 90 degrees, such as by sitting in a low chair, sitting down too fast, crouching or leaning forward quickly to the feet. If an infection develops, for example chest, teeth or bladder, then the doctor should be informed as infections can settle in an artificial joint.