Wedged Orthoses and Knee Osteoarthritis
The five-year goal of this project is to investigate the effect of in-shoe wedged orthoses on lower extremity function in patients with knee osteoarthritis. In general, our aims address the immediate effects of orthoses, the long-term effects of orthoses, and the immediate and long-term treatment effects comparing medial versus lateral wedged orthoses. The investigators hypothesize the wedged orthosis will result in altered gait mechanics that reflect a reduction in knee joint forces, reduced knee joint pain and increased function during weight bearing activities.
|Study Design:||Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Single Group Assignment
Masking: Single Blind
Primary Purpose: Treatment
|Official Title:||Effect of in-Shoe Wedges on Knee Osteoarthritis|
- knee abduction moment at baseline and one year
- WOMAC at baseline and one year
- 6 minute walk and stair climb pain and functional at baseline and one year
|Study Start Date:||February 2002|
Introduction: In shoe wedged orthoses have been shown to be an effective conservative approach in reducing pain in patients with osteoarthritis (OA). The mechanism responsible for this pain reduction is not well-understood. It is not known whether placing a medial or lateral wedge in the shoe results in alterations in lower extremity alignment, knee joint moments or some combination of the two. In addition, it has been suggested that patients with lateral knee joint OA (treated with medial wedges) respond more favorably than those with the more commonly diagnosed medial knee joint OA. Finally, the longterm effects of this intervention on OA patients' functional status as well the progression of their OA has not been studied. Therefore, the purpose of this study is to examine the effect of in-shoe wedged orthoses in patients with knee OA on static alignment measures, dynamic lower extremity mechanics and functional measures. In addition, the longterm effect of this treatment will also be examined. Methods: 120 patients between the ages of 40-70 yrs with knee OA (grades I-IV) will be recruited from within the medical community. Subjects with a diagnosis of unilateral knee OA of greater than 3 months duration, as defined by the American College of Rheumatology Guidelines, will be included. 60 subjects with medial joint OA and 60 with lateral joint OA will be recruited. 30 subjects within each group will be assigned to a treatment or control group such that groups will be balanced in terms of OA severity (determined by grade). The treatment group will receive custom molded orthotics with a medial (for lateral OA) or lateral (for medial OA) wedge. Both the treatment and control groups will be tested initially and then again 1 year later. The dependant variables will include static alignment measures (tibiofemoral and mechanical axis angles), biomechanical variables (frontal plane rearfoot and knee angles and moments) and functional scores (WOMAC functional assessment score and VAS pain score during walking and stair negotiation). Statistics: A series of two-way ANOVAs will be used to test hypotheses in aims 1 and 3. This design will include 2 levels of group (medial OA and lateral OA) and three levels of trials (pretest, wedge at initial, wedge at 1 yr.). Another series of two-way ANOVAs will be used to test hypotheses in aim 2. This design will include 2 levels of group (control and treatment) and two levels of trial (pretest and 1 yr posttest). Significance will be determined at a level of p<.05.