Novel Pre-Surgery Exercise-Conditioning in Patients Waiting for Total Knee Arthroplasty (TKA)

Total knee arthroplasty (TKA) is the treatment of choice for patients suffering from severe pain and functional limitation caused by osteoarthritis (OA) of the knee joint's surfaces (Magee et al. 2009). Within the UK, over 60,000 TKA surgeries are registered yearly (NJR 2015), making TKA one of the most common surgeries of the joint. Rehabilitation following surgery is essential for recovery and with TKA this is crucial in regaining movement, function and control. Current rehabilitation mainly focuses on post-surgery rehabilitation to increase range of motion (ROM) and muscle power, and to aid in achieving a quick return to functional independence for patients. Despite this, research has shown that patients undergoing TKA, still continue to experience reduced capacities in neuromuscular responses which are required for quick knee joint reactions, stability and proprioception, up to months following TKA surgery (Silva et al. 2003). A deficit in an individual's knee joint proprioception (synonymously referred to as a deficit in sensorimotor performance), together with impaired strength, can lead to reduced functional balance capabilities and movement control (Piva et al. 2010; Rätsepsoo et al. 2011), and can also contribute to injury (Lephart et al. 1997) and a greater risk of falls (Swinkels et al. 2009; Bade et al. 2010; Rätsepsoo et al. 2011). In part, the latter may be due to time-constraints within the health-care system, where a necessary preservation of the primary focus, to decrease pain and improve general function in patients following a TKA, has sometimes been to the detriment of other aspects of rehabilitation.

Pre-surgery exercise-conditioning:

Studies have investigated the effects of pre-surgery exercise' (also known as pre-habilitation exercise) interventions on strength and sensorimotor performance deficits in patients undergoing TKA, through various modes of exercise. Their aim has been to utilise a period of time pre-surgery to improve patients' rehabilitation status (Huber et al. 2015; Topp et al. 2009; Desmueles et al. 2013; Mackay et al. 2012). However, the patterns of patients' adaptations to the generic exercise stimuli used within these studies, has not shown the gains that had been expected by physiological dose-response, and ultimately questioned the efficacy of using pre-habilitation for effective gains in long-term outcomes. Nevertheless, the concept of achieving early gains to conditioning status that might potentiate patients' later rehabilitation processes and status, remains attractive to the latter (Calatayud et al. 2016, Huber et al. 2015) and the NHS (Rooks et al. 2006; Crowe and Henderson, 2003).

Conditioning for enhanced sensorimotor performance has been consistently endorsed in the sports-medical and sports-performance (Hubscher et al. 2010; Mandelbaum et al. 2005) and clinical literature (Tsao et al. 2007; Granacher et al. 2006) for its causal relationship to reduced injury likelihood and capability to improve function. While the precise dose of stimuli to achieve gains in sensorimotor performance is less clearly defined, enhancing motor performance by means of exercise that resist the effects of gravity or externally-applied loading to a joint system, has established underpinnings physiologically by improving motor performance and indirectly effecting sensorimotor responses (Vikne et al. 2006; Hakan et al. 2002; Moran et al. 2007). Clinically, the challenge has been to formulate a suitably pragmatic programme of conditioning that will accommodate the time- and cost-pressures associated with contemporary care practice while simultaneously offering efficacy when delivered prior to surgery as a pre-habilitative intervention. Rehabilitative and prophylactic conditioning programmes used in current studies for enhanced neuromuscular and sensorimotor performance, have typically required and been delivered in a duration of 6-8-weeks (Calatayud et al. 2016; Huber et al. 2015; Topp et al. 2009; Desmueles et al. 2013; Mackay et al. 2012). This has commanded a substantive logistical burden to elicit expected gains.

A novel approach to conditioning - Development of the P-SEC protocol: