Early Neuromuscular Electrical Stimulation For Quadriceps Muscle Activation Deficits Following Total Knee Replacement

• Changes in quadriceps activation and size,quadriceps muscle activity (EMG) during functional activities [ Time Frame: Baseline through 6 months ] [ Designated as safety issue: No ]
• Functional performance measures (self-reports, 6 minute walk distance, get up and go time, and functional stair climbing time) [ Time Frame: Baseline through 6 months ] [ Designated as safety issue: No ]

• Changes in quadriceps activation and size, presynaptic inhibition (H- reflexes), quadriceps muscle activity (EMG) during functional activities [ Time Frame: Baseline and 1 year ] [ Designated as safety issue: No ]
• Functional performance measures (self-reports, 6 minute walk distance, get up and go time, and functional stair climbing time) [ Time Frame: Baseline and 1 year ] [ Designated as safety issue: No ]

The purpose of this study is to determine whether early intervention with neuromuscular electrical stimulation (NMES) for muscle strengthening immediately after total knee replacement (TKR) is more effective than voluntary exercise alone in countering changes in quadriceps muscle activation, force production, and function in older adults.

Osteoarthritis (OA) is a chronic degenerative joint disease that disables about 10% of people over the age of 60 and compromises the quality of life of more than 20 million Americans. To alleviate pain and disability associated with knee OA, over 400,000 total knee arthroplasty (TKA) are performed each year in the United States, and future projections indicate that by the year 2030, more than 750,000 TKAs will be performed per year. While TKA reliably reduces pain and improves function, the recovery of force and function to normal levels is rare, which predisposes patients to future disability with increasing age. A month after TKA, impairments in quadriceps force are predominantly due to reflex inhibition, but are also influenced, to a lesser degree, by muscle atrophy. Neuromuscular electrical stimulation (NMES) may offer a promising alternative approach to override quadriceps reflex inhibition and prevent muscle atrophy to restore normal quadriceps muscle function more effectively than voluntary exercise alone, especially when applied within the first days after surgery.

The overall goal of this study is to evaluate the efficacy of NMES initiated 48hrs after TKA as an adjunct to standard rehabilitation. NMES is expected to more effectively restore normal quadriceps muscle function to produce greater quadriceps force by decreasing reflex inhibition. Patients will be randomized into one of two rehabilitation groups: 1) the standard rehabilitation group or 2) standard rehabilitation + NMES.

• Procedure: Neuromuscular Electrical Stimulation (NMES)
  20 minutes twice a day for 6 weeks
• Behavioral: Standard Rehabilitation Protocol
  Standard physical therapy for 8 weeks after surgery

• Experimental: 1
  Interventions:

  • Procedure: Neuromuscular Electrical Stimulation (NMES)
  • Behavioral: Standard Rehabilitation Protocol
• Active Comparator: 2
  Intervention: Behavioral: Standard Rehabilitation Protocol

• Mintken PE, Carpenter KJ, Eckhoff D, Kohrt WM, Stevens JE. Early neuromuscular electrical stimulation to optimize quadriceps muscle function following total knee arthroplasty: a case report. J Orthop Sports Phys Ther. 2007 Jul;37(7):364-71.
• Mizner RL, Petterson SC, Stevens JE, Vandenborne K, Snyder-Mackler L. Early quadriceps strength loss after total knee arthroplasty. The contributions of muscle atrophy and failure of voluntary muscle activation. J Bone Joint Surg Am. 2005 May;87(5):1047-53.
• Mizner RL, Petterson SC, Stevens JE, Axe MJ, Snyder-Mackler L. Preoperative quadriceps strength predicts functional ability one year after total knee arthroplasty. J Rheumatol. 2005 Aug;32(8):1533-9.
• Stevens-Lapsley JE, Balter JE, Wolfe P, Eckhoff DG, Schwartz RS, Schenkman M, Kohrt WM. Relationship between intensity of quadriceps muscle neuromuscular electrical stimulation and strength recovery after total knee arthroplasty. Phys Ther. 2012 Sep;92(9):1187-96. Epub 2012 May 31.
• Stevens-Lapsley JE, Balter JE, Wolfe P, Eckhoff DG, Kohrt WM. Early neuromuscular electrical stimulation to improve quadriceps muscle strength after total knee arthroplasty: a randomized controlled trial. Phys Ther. 2012 Feb;92(2):210-26. Epub 2011 Nov 17.

Inclusion Criteria:

• 50 years of age or older
• Scheduled for a unilateral or bilateral primary TKR
• Body mass index less than 35
• Cognitive status that allows patients to consistently comprehend and repeat back directions regarding the details of the study

Exclusion Criteria:

• History of uncontrolled diabetes; HbA1c levels greater than 8%
• Neurological, vascular or cardiac problems that significantly limit function
• Moderate or severe osteoarthritis or other orthopedic conditions in the non-operated lower extremity that limit function
• Alcoholism or drug abuse

• National Institute on Aging (NIA)
• American College of Rheumatology Research and Education Foundation