The Effect of Neuromuscular Training on Osteoarthritis: A Comparative Prospective Randomized Study
Condition: Knee Osteoarthritis
MeSH terms: Osteoarthritis; Osteoarthritis, Knee
Study type: Interventional

Summary: 
      Context: The many treatments and devices developed to unload the diseased articular surface
      in knee osteoarthritis have provided limited solutions. A novel biomechanical device
      comprising of four individually calibrated elements attached onto foot-worn platforms was
      recently developed. This device is capable of such unloading during standing and walking,
      simultaneously strengthening dynamic stabilizers and training neuromuscular control by
      controlled biomechanical perturbations.

      Objective: To asses the effectiveness of this device in reducing pain and improving function
      in patients with knee osteoarthritis.

      Design and Setting: Randomized, controlled and double blind prospective trial, conducted from
      September 2005 to February 2006, in the Department of Orthopedics, Asaf Harofeh Medical
      Center (Zerifin, Israel).

      Patients: Sixty-one patients with diagnosed knee osteoarthritis who self-reported
      moderate-to-severe level pain.

      Interventions: Patients were randomly assigned into active and control groups and underwent 8
      weeks of treatment. The active group was treated with the device and its four biomechanical
      elements that had been individually calibrated to accommodate a pain-free joint alignment.
      The control group was treated with the device's platforms without the biomechanical elements.

      Primary Outcome Measures: The patients were evaluated three times during the study: at
      baseline, after 4 weeks and at the 8 week endpoint. Primary outcomes were the Western Ontario
      and McMaster Osteoarthritis Index (WOMAC) and the Aggregated Locomotor Function (ALF)
      assessment.
    

Detailed description: 
      The Biomechanical System The biomechanical system is a biomechanical device (US Patent No.
      6,979,287) combined with a treatment methodology (US Patent No. 7,101,330). The device is
      calibrated for the individual patient according to pathology and motion characteristics.
      Appropriate calibration is defined as bringing the damaged joint to a biomechanical alignment
      that minimizes/eliminates pain by shifting and/or changing the applied forces and,
      consequently, altering pressure distribution within the joint. Together with the
      biomechanical perturbation applied through all phases of the step-cycle (i.e. initial
      contact, mid-stance and toe-off), this enables home-based, dynamic, functional and repetitive
      training to strengthen dynamic stabilizers and improve neuromuscular control.

      The device consists of two half spherical-shaped biomechanical elements attached to each of
      the patient's feet. One is located under the hindfoot region and the other is located under
      the forefoot region. The elements are available in different degrees of resilience and
      convexity, and are attached to the patient's foot using a platform in the form of a shoe. The
      platform is equipped with a specially designed sole, which consists of two mounting rails to
      enable flexible positioning of each element under each region.

      A specific level of "unloading" under a specific level of perturbation is required for
      controlling pain in the affected compartment while reducing excessive loads of soft tissue
      structures. Primary guidelines for calibration dictate the choice of resilience, convexity
      and the position of each element. For example, in a genu-varus deformity the elements are
      positioned under the neutral axis of the patient's leg. The element under the hindfoot is
      further translated laterally to the longitudinal axis of the patient's leg in order to apply
      wedging, while the element under the forefoot is further translated medially to reduce the
      tension applied by soft tissue in the medial compartment, and to decrease adduction moment.
      When required, further soft tissue tension and/or pressure can be decreased by adding plantar
      flexion and/or forward translation of the hindfoot element.

      Pain and motion instability are periodically evaluated to determine whether recalibration is
      required.

      Treatment (Active) Protocol The device was calibrated for each patient after baseline
      assessment. Then, treatment was initiated and continued daily for a period of 8 weeks, during
      which the device was again calibrated, as necessary, after the first, third and sixth week.
      Patients were instructed to follow a treatment protocol which was based on walking during
      activities of daily living and started with 10 minutes of indoor walking each day during the
      first week and gradually increased to 30 minutes of daily outdoor walking in the last week.
      Other than that, they were told to continue their daily activities wearing their regular
      footwear. They were also instructed not to ingest any pain relief medication, non-steroidal
      anti-inflammatory drugs or food supplements except for the acetaminophen tablets (unmarked)
      that had been given to them at study entry to be taken when needed. The consumption of
      acetaminophen or any other medication was monitored during each assessment.

      Control Protocol Patients in the control group were fitted with a platform which was
      identical in appearance but had a regular sole and did not include the biomechanical
      elements. They were instructed to follow the same treatment protocol as the active group and
      not to ingest any medication or food supplement apart from the unmarked acetaminophen tablets
      that had been given to them.

      Assessment We tested the clinical efficacy of a device designed for reducing pain and
      improving function in knee osteoarthritis patients by means of the self-reported Western
      Ontario and McMaster Osteoarthritis Index (WOMAC) and the measured aggregated locomotor
      function (ALF). The WOMAC is composed of a 5 items pain scale, a 2 items stiffness scale and
      a 17 items function scale. All 24 items are rated by the patients on a visual-analogue-scale
      (in cm) from 0 (no symptoms/limitations) to 10 (maximal symptoms/limitations). The ALF scale
      is a sum of mean timed score (seconds) of three locomotor functions: time taken to walk 8
      meters, time taken to accent and decent 7 stairs and time taken to transfer from sitting to
      standing. The patients were evaluated three times during the study: at baseline, after 4
      weeks and at the 8 week endpoint. Measurements were made with the patients barefooted as
      required by the outcome protocol.

      To ensure our ability to detect clinically significant differences, we also used the SF-36
      health survey and the Knee Society Score as self-reported secondary outcomes (the latter
      includes a physical examination subscale).
    

Intervention name(s): APOS biomechanical gait system
Intervention type(s): Device
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double
Primary purpose: Treatment
Keywords: Knee; Osteoarthritis; WOMAC; ALF; Wedging