An optimal duration of daily wear for an insole with subtalar strapping in patients with varus deformity osteoarthritis of the knee.

OBJECTIVE

To assess the optimal duration of daily wear for a laterally wedged insole with subtalar strapping in subjects with medial compartment osteoarthritis of the knee (knee OA).

DESIGN

The setting was an outpatient clinic. Eighty-one patients with knee OA were prospectively randomized according to birth date and to either 2 weeks of treatment with a lateral wedge with subtalar strapping for less than 5 h (the short group), 5-10 h (the medium group) or greater than 10 h (the long group) each day, or to treatment with a subtalar strapping band without lateral wedge (the placebo group). Standing radiographs were used to analyze the femorotibial angle for each subject, both with and without their respective orthotic device. The remission scores of Lequesne index were compared among the four groups at the conclusion.

RESULTS

The short (n=21), medium (n=20) and long (n=18) groups demonstrated a significant greater valgus correction of the femorotibial angle than the placebo group (n=22) (P<0.0001). The remission score was significantly improved in the medium group compared to the placebo (P=0.001) and long (P=0.001) groups.

CONCLUSIONS

An optimal duration of insole with subtalar strapping wear for patients with varus deformity knee OA may be between 5 and 10 h each day.