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.
On return from operation the physiotherapist will check the patient’s operative record, medical observations and assess the patient. Initial physio treatment consists of checking respiratory status and the muscle power and feeling in the legs to exclude nerve injury. Exercises are given to restore normal movement although an epidural can cause loss of movement in the legs and delay progress. The physiotherapist will then mobilise the patient with an assistant, taking care of the hip precautions, stand them up and walk them a short distance with elbow crutches or a frame.
Toes, ankles, quadriceps, hip flexion and buttock exercises continue to restore normal muscle activity to the legs and maintain the circulation. Routine painkillers should be taken as this helps patients get up and about and once safe they can get up three times a day or more with a helper to walk, toilet and wash. Usual precautions are taken and when sat out the chair must be the correct height and normally patients do not put their feet up whilst sitting.
After hip replacement patients require instruction and correction to achieve a normal walking pattern, develop muscular power and improved function. Physiotherapists teach the appropriate gait at the time, often starting with “step to” where the patient moves the walking aid, steps the operated leg forwards and steps up to it with the other leg, a stable and safe pattern. Progression is to ‘step through” where the unaffected leg steps beyond the other in an approximation of a normal walking pattern. Patients often progress naturally then to a gait where they move both the crutches and the affected leg forward at the same time and start to walk in a fully natural pattern.
Once they return for their follow up appointment at six weeks after operation patients have often achieved a good gait, reasonable hip strength and returned to some activities of daily living. The physio may advise a stick if they are unsteady, slow or older, and they can gradually regain their previous abilities provided they observe the precautions to prevent hip dislocation: Avoid hip flexion over 90 degrees by not sitting down in low seating, not sitting down or standing up too quickly, not bending over to the floor quickly and not crouching. Weight bearing on the leg and rotating the body weight is unwise. Get medical advice if an infection develops e.g. in the bladder, chest or teeth, as this can transfer to an artificial joint. Avoid crossed legs in sitting.