Physiotherapy Management of Hip Replacement

Populations across the world suffer from osteoarthritis (OA), the most common degenerative joint condition in world, causing large amounts of pain, disability and expense. Western developed populations are ageing and as the incidence of OA rises with each decade of life the impact of this condition will be felt ever more strongly. Less developed countries such as China will soon be joining the countries with ageing populations so the need for effective OA treatment will increase greatly. One of the approaches to managing OA is to perform 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.

In surgery the degenerative joint is excised and artificial components of alloy steel and plastic are substituted. The hip joint ball is removed and the socket cored out in preparation, the new ball and stem is inserted into pressurized cement in the femur and the new cup is pressed into cement in the socket. The two materials, steel alloy and ultra high density polyethylene, ensure very low friction in the joint similar to the original and contribute to low wear and long life of the joint.

The physiotherapist will review the patient's medical notes for their post-operative instructions and medical status and then assess the patient's respiratory and lower limb function. Assessment of leg muscle function and sensory ability is important to exclude nerve injury and the physio will give leg exercises to get the limb moving, although an epidural can slow this process by reducing power and feeling for a while. The patient will be mobilised up into walking by the physiotherapist and an assistant, using a frame or elbow crutches and observing hip safety 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.

Physiotherapists routinely teach and correct patients' gait after hip replacement to improve joint movement, muscle strength and a normal walking pattern. On getting a patient up initially the physio will teach the "step to gait", instructing the patient to place the crutches forward at first, place the operated leg between the crutches then following it by stepping to it with the unoperated leg. This technique is steady but slow and used when safety is key, and the next progression is to a "step through gait" where the unoperated leg then moves through past the operated leg into a more normal gait. The most advanced gait sees the operated leg and the crutches moving together at the same time and gait approaching normal.

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.