Total hip replacement (THR) is one of the most widely performed procedures in orthopaedic practice and with the increasing age of the population; the number of persons who require such surgery is on the rise, . In England and Wales, according to the National joint registry, the number of primary total hip replacements (THR) in 2009/2010 totalled 79413, which is a steady rise from the amount reported in 2008/2009 (77608) and 2007/2008 (73632), . THR has revolutionalised the care of patients with end stage joint disease, leading to pain relief, and substantial improvement in quality of life, . However, long-term studies show that, even in the absence of pain, there is persistence of impairment and functional limitation, . These long lasting impairments include reduced muscle strength, reduced postural stability, and limited flexibility, . The functional limitations include reduced walking speed, and lower ratings on various assessment tools used to measure functional ability compared with those who have never had hip arthritis, .
Considerable technical efforts have been made towards optimising THR; for example, there are over 100 varieties of hip prostheses, multiple bearing couples, and several surgical approaches. However, the actual health gain for many of these innovations is small in terms of patient function and quality of life, . In tandem with these technical developments, patient expectations, including for an early return to normal physical function and activities; have also increased, . In the recent past, a prolonged hospital stay after THR incorporated a period of rehabilitation. However, due to the introduction of initiatives such as integrated care pathways and considerations of cost and patient satisfaction, the length of hospital stay following joint replacement has reduced markedly over the past decade from a mean of 3 weeks to 4 days .
Since the evidence suggests patients who score poorly on subjectively assessed functional outcome measures 2 years post-operatively after THR are five times more likely to require assistance with ADLs compared to those who have good function, , rehabilitation may therefore increasingly important to avoid long-term impairment and to optimise functional recovery, .
Prior to surgery, there is a general deficit in muscular strength along the affected limb as compared to the contra-lateral (healthy) side in patients with unilateral hip osteoarthritis (OA), and muscles such as the abductors, vastii, rectus femoris and psoas show marked atrophy, . Immobilisation due to major surgery and hospitalisation can cause a further decline in muscle mass, muscle strength and muscle function, . Muscle strength declines 4% per day during the first week of immobilisation, and the deficits in the involved hip after THR range from 10-21% when compared to the uninvolved hip at 1 year post-surgery, [12, 13] the atrophic changes that occur about the hip persist up to 2 years following THR, .
The most commonly used rehabilitation regimes for older people are based on functional types of exercises which do not involve external loading and have not been shown to prevent further muscle atrophy after THR [5, 14]. In contrast, progressive resistance training (PRT) is an effective method for inducing muscle hypertrophy and increasing muscle strength and functional performance in healthy and clinical populations, including the elderly, . PRT elicits positive health and performance adaptations by challenging the skeletal muscles with loads that can be lifted repetitively until the onset of neuromuscular fatigue, i.e. the point at which appropriate technique can no longer be maintained, . To facilitate continued adaptation, training load is progressively increased, and exercises are adjusted as indicated throughout the training regimen, to attenuate the onset of a plateau in physiological adaptation.
PRT in rehabilitation following THR has been shown to significantly enhance muscle strength and function, [16–18] with PRT being the main factor in achieving significant functional improvements in rehabilitation regimes used after home or centre based regimes used after THR, . Although a plethora of studies exist testing different rehabilitation protocols (including PRT) against ‘standard’ practice, [20, 21] no explicit definition is made as to what ‘standard practice’ entails. Clarification of the variation in the available rehabilitation programs after this common operation is therefore important. The aims of this study were firstly to define standard rehabilitation care following THR in the UK and secondarily to determine whether PRT is prescribed as part of standard care.