A six‐month followup of a randomized trial comparing the efficacy of a lateral‐wedge insole with subtalar strapping and an in‐shoe lateral‐wedge insole in patients with varus deformity osteoarthritis of the knee

Abstract

Objective. To assess the effect of a lateral-wedge insole with elastic strapping of the subtalar joint on the femorotibial angle in patients with varus deformity of the knee.Methods. The efficacy of a wedged insole with subtalar straps and that of a traditional wedged insole shoe insert were compared. Sixty-six female outpatients with knee osteoarthritis (OA) were randomized (according to birth date) to be treated with either the strapped or the traditional inserted insole. Standing radiographs with unilateral insole use were used to analyze the femorotibial angles for each patient. In both groups, the baseline and 6-month visual analog scale (VAS) scores for subjective knee pain and the Lequesne index scores for knee OA were compared.Results. The 61 patients who completed the 6-month study were evaluated. At baseline, there was no significant difference in the femorotibial angle (P ‫؍‬ 0.66) and the VAS score (P ‫؍‬ 0.75) between the 2 groups. At the 6-month assessment, the 29 subjects wearing the subtalar-strapped insole demonstrated a significantly decreased femorotibial angle (P < 0.0001) and significantly improved VAS scores (P ‫؍‬ 0.001) and Lequesne index scores (P ‫؍‬ 0.033) compared with their baseline assessments. These significant differences were not observed in the 32 subjects assigned to the traditional shoe-inserted wedged insole. Conclusion.These results suggest that an insole with a subtalar strap maintained the valgus correction of the femorotibial angle in patients with varus knee OA for 6 months, indicating longer-term clinical improvement with the strapped insert compared with the traditional insert.

Kinematic adaptations to a variable stiffness shoe: Mechanisms for reducing joint loading

“…The variable stiffness shoe results are in contrast to studies with laterally wedged insoles that in both healthy and subjects with OA have had mixed results (Baker et al, 2007;Bennell et al, 2011;Fang et al, 2006;Kakihana et al, 2007;Kutzner et al, 2011;Toda and Tsukimura, 2004). The mechanism by which the external adduction moment is reduced in the VS shoe is not clear.…”

“…A comparison of the dynamic changes associated with the variable stiffness shoe to kinematic changes in fixed interventions such as lateral wedge shoes might help to explain the difference in the clinical outcome (Erhart et al, 2010) with this shoe relative to the inconsistent results seen with wedged interventions (Kakihana et al, 2007;Toda and Tsukimura, 2004). The primary difference between response to lateral wedge interventions and the variable stiffness shoe is the direction of shift in the COP in combination with the change in the m-l GRF (Fantini Pagani et al, 2011;Kakihana et al, 2007).…”

Effects of footwear on medial compartment knee osteoarthritis

“…Toda and Tsukimura observed clinical and structural improvements at 6-month assessment in subjects who wore a subtalarstrapped lateral-wedge insole [12]. At the 6-month assessment, the subtalar-strapped lateral-wedge insole group demonstrated significantly decreased femorotibial angles, improved VAS scores, and improved Lequesne index scores compared with their baseline assessments, while those who wore the traditional shoe-insert wedge insole did not demonstrate changes [12]. At the 2-year assessment, the significantly decreased femorotibial angles and improved Lequesne index scores remained for those wearing the subtalar-strapped lateral-wedge insole [30].…”

“…At the 2-year assessment, the significantly decreased femorotibial angles and improved Lequesne index scores remained for those wearing the subtalar-strapped lateral-wedge insole [30]. Toda and Tsukimura suggested that the movement of the talus by the insole may interfere with calcaneal valgus correction and subsequently prevent femorotibial correction [12]. With the subtalar-strapped lateral-wedge insole, decreased femorotibial angles may restrict the progression of degenerative articular cartilage lesions of knee OA [30].…”

“…One randomized controlled study showed that subjects with medial compartment knee OA decreased nonsteroidal anti-inflammatory drug (NSAID) intake when they wore bilateral lateralwedge insoles but did not report any change in pain, stiffness, or function as measured by the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index [11]. Women with medial compartment knee OA who wore bilateral lateral-wedge insoles with elastic strapping of the subtalar joint had a significant decrease in femorotibial angle and visual analog scale (VAS) score for subjective knee pain and an improvement in Lequesne index scores (a measure of disease severity) [12]. These changes were not observed in women who wore traditional shoeinserted lateral-wedge insoles.…”