Exploratory insights into novel prehabilitative neuromuscular exercise-conditioning in total knee arthroplasty

Contemporary strategies for prehabilitation and rehabilitation associated with total knee arthroplasty (TKA) surgery have focused on improving joint range-of-motion and function with less emphasis on neuromuscular performance beneficially affecting joint stability. Furthermore, prehabilitation protocols have been found to be too long and generic-in-effect to be considered suitable for routine clinical practice.

A pragmatic exploratory controlled trial was designed to investigate the efficacy of a novel, acute prehabilitative neuromuscular exercise-conditioning (APNEC) in patients electing TKA. Adults electing unilateral TKA were assessed and randomly allocated to exercise-conditioning (APNEC, n = 15) and usual care (Control, n = 14) from a specialised orthopaedic hospital, in the United Kingdom. APNEC prescribed nine stressful exercise-conditioning sessions for the knee extensors of the surgery leg, accrued over one week (3 sessions·week^-1; 36 exercise repetitions in total; machine, gravity-loaded) and directly compared with usual care (no exercise). Prescribed exercise stress ranged between 60%-100% of participant's daily voluntary strength capacity, encompassing purposefully brief muscular activations (≤ 1.5 s). Baseline and follow-up indices of neuromuscular performance focusing on muscle activation capacity (electromechanical delay [EMD], rate of force development [RFD] and peak force [PF]) were measured ipsilaterally using dynamometry and concomitant surface electromyography (m. rectus femoris_[RF] and m. vastus lateralis_[VL]).

Group mean ipsilateral knee extensor muscular activation capacity (EMD_RF [F_(3,57) = 53.5; p < 0.001]; EMD_VL [F_(3,57) = 50.0; p < 0.001]; RFD [F_(3,57) = 10.5; p < 0.001]) and strength (PF [F_(3,57) = 16.4; p < 0.001]) were significantly increased following APNEC (Cohen's d, 0.5-1.8; 15% to 36% vs. baseline), but unchanged following no exercise control (per protocol, group by time interaction, factorial ANOVA, with repeated measures), with significant retention of gains at 1-week follow-up (p < 0.001).

The exploratory APNEC protocol elicited significant and clinically-relevant improvement and its retention in neuromuscular performance in patients awaiting TKA.

(date and number): clinicaltrial.gov: NCT03113032 (4/04/2017) and ISRCTN75779521 (3/5/2017).