Modulation of Vastus Medialis Corticomotor Excitability Following Sensorimotor Perturbation Training after Total Knee Arthroplasty using Transcranial Magnetic Stimulation: A Case Report
TL;DR
The present case report suggests that sensorimotor training along perturbation exercises may serve as an adjunct to conventional rehabilitation strategies to promote corticomotor excitability and functional activities following TKA, however, further controlled trials are needed to prove its effectiveness.
Abstract
Total knee replacement is a treatment for end-stage knee osteoarthritis that reduces pain and restores function, but is often limited by plateaued neuromuscular function, such as reduced corticomotor excitability, which may have long-term implications for health and Quality of Life (QoL). Sensorimotor training along perturbation exercises is a relatively new technique of neurophysiological rehabilitation which can stimulate the activity of the cortex and motor control. Although the quadriceps functions as a muscle group, the vastus medialis was specifically assessed because it is highly affected by arthrogenic muscle inhibition after Total Knee Arthroplasty (TKA) and plays a key role in knee stability. The present case report examined the effects of sensorimotor training along perturbation exercises on the vastus medialis corticomotor excitability of a patient with a TKA. In the present report the objective and the subjective outcome measures were used. After unilateral TKA, a 58-year-old female patient expressed pain in knee {Numeric Pain Rating Scale (NPRS) 4/10}, stiffness of knee, and difficulty climbing stairs and standing long, 4 weeks after surgery. The clinical results were knee flexion being 95°, extension lag 10° and quadriceps strength was 3/5 on Medical Research Council (MRC) scale. The initial examination revealed a lower level of corticomotor excitability; Motor Evoked Potential (MEP) amplitude was 0.42 mV, Resting Motor Threshold (RMT) was 65%, Timed Up and Go (TUG) time was 15.1 s, NPRS score was 4/10, knee Range of Motion (ROM) was 0-95°, extension lag was 10°, and quadriceps strength was MRC grade 3/5. The Knee Injury and Osteoarthritis Outcome Score (KOOS) subscale scores were out of 100; 54 for pain, 55 for symptoms, 56 for Activities of Daily Living (ADL), 50 for sports/ recreation, and 52 for QoL. The patient received a sensorimotor training along perturbation exercises was administered three times weekly for four weeks (12 sessions), with each 45-minute session comprising a 10-minute warm-up, 30-minute training period, and 5-minute cool-down. Conventional exercises and home advice were provided on non treatment days. The post-intervention results showed that significant changes in the corticomotor excitability and functional performance were observed. MEP amplitude increased by 0.43 mV (0.42 to 0.85 mV) and RMT decreased by 11 (65% to 54%). TUG time decreased by 4.9 s (15.1 to 10.2 s), NPRS score decreased by three points (4/10 to 1/10), knee ROM increased by 20° (0-95° to 0-115°), extension lag reduced by 8° (10° to 2°), and quadriceps strength improved from MRC grade 3/5 to 4/5. KOOS subscale scores improved by 28 points for pain (54 to 85), 27 points for symptoms (55 to 82), 31 points for ADL (54 to 85), 30 points for sports/recreation (50 to 80), and 31 points for QoL (52 to 83). The findings of the present case report suggests that sensorimotor training along perturbation exercises may serve as an adjunct to conventional rehabilitation strategies to promote corticomotor excitability and functional activities following TKA. However, further controlled trials are needed to prove its effectiveness.