An appraisal of rehabilitation regimes used for improving functional outcome after total hip replacement surgery

Symptomatic hip osteoarthritis occurs in 3% of the elderly [1] and is associated with poor general health status [2]. Treatment strategies for hip pain have usually involved conservative measures (analgesia, exercise, education, weight reduction), with surgical intervention (total hip replacement; THR) being the most effective treatment for end stage disease [3]. The National Joint Registry for England and Wales reports that the number of primary total hip replacements performed in England and Wales in 2009/2010 totaled 79413, which is a steady rise from the numbers reported in 2008/2009 (77608) and 2006/2007 (51981)[4].The most common preoperative complaints by patients who elect to have THR are pain and loss of mobility [1,5]. It therefore follows that the most commonly reported outcomes of THR in the literature relate to pain relief and restoration of mobility [1]. It is clear that a major predictor of outcome after THR is the preoperative status - worse preoperative status is followed by a poorer absolute outcome as defined by several outcome measures [6]. Outcome studies of pain reduction and range of motion restoration, usually conducted 3 to 6 months after THR, indicate an overall satisfaction by patients and physicians [7]. However, outcome studies performed at least 1 year after THR reveal that limitations in physical function remain even in the absence of pain. These persisting impairments include decrements of 10-21% in muscle strength and postural stability of the involved hip relative to the non-operated hip at 1 year post-THR surgery [8,9], with these deficits still evident 2 years after surgery [2,10]. Interestingly, Long et al. [10] reported that muscle weakness during stance, along with deterioration of the Harris Hip score, were the most consistent findings in patients who developed loosening of the hip components; implying that muscle weakness may result in reduced protection of the prosthetic implant fixation.Prior to surgery, there is a general