Osteoathritis Clinical Trial
Official title:
Medial-Wedge Insole is Highly Effective in the Treatment of Valgus Knee Osteoarthritis
- To assess the efficacy of medial-wedge insole in valgus knee osteoarthritis (OA).
- We hypothesized that medial-wedged insoles are biomechanically effective and should
reduce lateral compartment loading in persons with valgus knee osteoarthritis with a
consequent symptomatic improvement.
Thirty females fulfilling the American College of Rheumatology criteria for knee
osteoarthritis with bilateral valgus deformity greater than or equal to 8° were
consecutively will be selected from the Rheumatology Outpatient Clinic of University of São
Paulo. Radiographic grading of OA was defined according to Kellgren and Lawrence (KL) and
analyzed blind by the same rheumatologist. Inclusion criteria were knee osteoarthritis with
lateral compartment involvement detected on X-Ray (KL class II or more); absence or minimal
(KL class 0 or I) for medial compartment involvement; and pain on movement > 2 measured by
Visual Analog Scale (VAS).
Exclusion criteria were: body mass index (BMI) > 40, scoliosis, lower limbs length
difference exceeding 1 cm, knee surgery, hallux rigidus, previous history of rheumatologic
disease (rheumatoid arthritis, connective tissue disease, microcrystalline arthropathy, and
soronegative arthropathy), soft tissue involvement (anserine, patellar, and calcaneal
tendinopathy), and foot/lower leg symptoms.
Corticosteroid and hyaluronic acid infiltrations were not allowed 3 and 6 months prior to
entry, respectively. The use of non-steroidal anti-inflammatory and analgesics or slow
action drugs (DMARDs) were allowed if prescribed at least four weeks and eight weeks before
entry and remained unchanged throughout the study.
The study was approved by the local Ethical Committee and all patients signed informed
consent.
Study protocol:
Patients will be randomly assigned into 2 groups: CASES with 16 patients and CONTROLS with
fourteen patients. The CASES wore 8 mm high, medial-wedged insoles for the hind foot
inserted into a new shoe for 8 weeks. The CONTROLS will use an insole resembling the former
group, only without raised wedges (FIGURE 1-B) for 8 weeks. Patients of both groups will
receive the same new shoe and were blind to the insole use.
The ethylene-vinyl-acetate (EVA - density 50) insoles were provided by the AACD Institute
(Handicapped Child Care Association). A commercial neoprene with elastic banding will be
used for ankle support. Both groups will use similar standard shoes supplied by the
hospital. Each participant will be instructed to use the splints (shoes and elastic banding)
for 3 to 6 hours daily. The correct use of the splints will be checked every two weeks.
Undesirable side-effects will be recorded at the end of the study.
Age, disease duration, weight, height, body mass index (BMI), and sedentarism (only daily
activities) will be recorded for all patients at entry. In order to assess symptoms, Visual
Analog Scale (VAS) will be used for night pain, pain at rest and on movement. Lequesne index
score and the WOMAC questionnaire will be applied at baseline and after 8 weeks by a blinded
examiner.
Antero-posterior conventional X-ray of knees and ankles will be performed under monopodalic
load with and without insoles in order to measure femorotibial, talocalcaneal, and talus
tilt angles. Femorotibial angle is formed by the intersection of femur and tibia axes,
obtained through lines drawn at distal one-third of the femur and proximal one-third of the
tibia, both equidistant from external limits of the cortical bones. Talocalcaneal angle is
formed by a first line connecting the midpoints between the trochanter talus to the lateral
and medial malleoli, and a second line perpendicular to the floor identified by inferior
border of X-ray. Tilt angle of talus is formed by a line parallel to floor and the tilt of
the trochanter talus. All angles will be measured blind by the same rheumatologist.
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Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double-Blind, Primary Purpose: Treatment