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.
Of all medical interventions, joint replacement has one of the highest increases in quality of life, transforming a person's mobility, outlook and independence. Developed in the 1960s to a level where mass treatment was feasible, total hip replacement has matured into a predictable and successful treatment for OA with very good results stretching to 15 years and beyond. Conservative treatments are the mainstay of management of OA but once it becomes severe hip replacement is the only option.
The surgeon removes the osteoarthritic joint surfaces and replaces them with new components which are made of steel alloy and ultra high density polyethylene. The ball of the hip is replaced by a metal ball and stem and inserted into pressurized cement in the femoral canal. The plastic socket is pushed into the cement in the prepared socket to complete replacement of the two surfaces. Using the two materials, very slippery plastic and highly polished metal, ensures very low joint friction and a long functional life under load.
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.
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.
Jonathan Blood Smyth
Author Bio
Jonathan Blood Smyth is a Superintendent Physiotherapist at an NHS hospital in the South-West of the UK. He specialises in orthopaedic conditions and looking after joint replacements as well as managing chronic pain. Visit the website he edits if you are looking for physiotherapists in Liverpool.
