Long-Term Effectiveness of Walking Training in Patients With Knee Osteoarthritis

Nearly one out of every two Americans will develop knee osteoarthritis by age 85. Over 20 million Americans, including nearly three million Veterans, currently have painful knee arthritis that limits their daily activity or recreation. The vast majority of those individuals will be prescribed anti-inflammatory drugs that provide some pain relief but do not slow the progression of the disease. Often people with knee arthritis are told they must live with the pain until they become appropriate candidates for knee replacement surgery, but that can require tolerating the pain and limiting function for many years. Because of other health issues, some individuals are never acceptable surgery candidates. What is desperately needed are better conservative approaches for treating these patients. Two such approaches will be tested and compared in this study.

This study is a randomized controlled trial to investigate conservative treatments for individuals with painful knee osteoarthritis (OA). The study will recruit participants who have isolated, medial compartment knee OA. Subjects will be assigned to one of two gait training groups. Both groups will undergo gait analysis to determine their foot progression angle at their comfortable walking speed. Both groups will receive personalized gait retraining to either alter their foot progression angle or to achieve consistency of their natural foot progression angle.

Gait retraining will consist of once a week sessions for six weeks. The gait training will use a fading feedback approach, where the percentage of each weekly session during which feedback is used is decreased from week to week until no feedback is used by the last training session. Throughout the six-week training period subjects will be encouraged to practice their gait for at least ten minutes per day. Subjects will continue to practice their gait throughout the remainder of the 52-week intervention. Subjects will have their walking activity recorded using a 3-axis pedometer. Compared to their baseline walking activity, participants will be instructed to increase their daily walking by ten minutes per day throughout the 52-week intervention.

All subjects will receive monthly phone calls to encourage maintaining a regular walking regimen. Walking activity will be monitored periodically using a pedometer. Subjects will receive knee MRIs and weight-bearing knee radiographs at the start and end of the study. All participants will complete pain evaluations and clinical knee score questionnaires during the study. The investigators expect that subjects in both groups will have a reduction in knee pain over the course of the 52-week intervention. The primary objective of the study it to determine if the change in pain between baseline and week 52 is different between the two groups.

Eligibility Criteria:
Inclusion Criteria:

* Diagnosed with isolated, medial compartment knee OA of at least six months duration
* Kellgren-Lawrence grade of I, II, or III
* Age greater than 18 years at the time of enrollment
* Ability to give informed consent
* Knee pain more than three days per week on average
* Average knee pain in medial compartment between 3 and 9 on an 11-point Numerical Rating Scale, and greater than pain in other compartments
* Ambulatory without aids
* Able to walk for at least 25 consecutive minutes
* Able to walk on treadmill safely at 0.7 m/s or faster
* Able to reduce the prominent peak of the knee adduction moment by changing foot progression angle

Exclusion Criteria:

* Body mass index equal to or greater than 35
* Pregnancy
* Plans for knee replacement within the next 12 months
* Contraindications to MRI
* Nerve or muscle disease associated with walking difficulty
* Narcotic pain medication usage
* History of rheumatoid arthritis or autoimmune disease
* An episode of gout or pseudogout in the knee in the past year
* History of neuropathic arthropathy, infectious disease, or other major systemic diseases
* Current or recent past use (within two months) of oral corticosteroids
* Cognitive impairments that would limit a subject's understanding
* Expecting a significant change in activity level or weight within the next 12 months
* Regularly participates in high impact activities such as running, soccer, basketball, etc.
* Unable to perform the 3rd stage of the 4-stage balance test, which involves holding a tandem stance for 10 seconds

The following criteria apply only to the affected osteoarthritic limb:

* History of symptomatic arthritis in lower limb joints other than the knees that is more severe than knee arthritis
* Replacement of any lower extremity joint
* Lateral tibiofemoral joint space width less than medial
* Recurrent giving way of the knee
* Symptoms arising primarily from a meniscal or ligament pathology or other structure not directly related to osteoarthritis as identified by physical exam, health record, or MRI
* Symptoms originating primarily from the patellofemoral joint
* Avascular necrosis
* Recent (within two months) knee injury or surgery
* Planned use of hinged knee brace in next 12 months
* Severe knee malalignment of more than 10 degrees from neutral
* Intra-articular injection within the past 2 months or planned for the next 12 months