Physiotherapy Management of Hip Replacement
Human populations are ageing across the world, particularly in developed countries such as the USA, Europe and Japan, with some developing countries such as China set to follow them over the next decades. This will place a large burden on physiotherapy and medical services as countries struggle to cope with steadily increasing levels of osteoarthritis (OA), an age-related degenerative condition. OA is responsible for significant levels of medical expenditure, disability, pain and work loss and provision of services such as joint replacement will be a challenge.
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.
Hip flexion, knee extension, buttock and calf exercises are practiced whilst in bed to reactivate the leg muscles and pump the blood around the limb. Routine analgesia is very useful as reduced pain allows easier exercising and mobilising. Patients can now go to the toilet, wash and dress and walk about the ward with a helper if needed, at least three times a day to get their confidence. When sitting, correct height chairs are vital and patients should avoid having their feet up on a stool.
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.
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.