Foot orthoses in the treatment of symptomatic midfoot osteoarthritis using clinical and biomechanical outcomes: a randomised feasibility study

Abstract

This randomised feasibility study aimed to examine the clinical and biomechanical effects of functional foot orthoses (FFOs) in the treatment of midfoot osteoarthritis (OA) and the feasibility of conducting a full randomised controlled trial. Participants with painful, radiographically confirmed midfoot OA were recruited and randomised to receive either FFOs or a sham control orthosis. Feasibility measures included recruitment and attrition rates, practicality of blinding and adherence rates. Clinical outcome measures were: change from baseline to 12 weeks for severity of pain (numerical rating scale), foot function (Manchester Foot Pain and Disability Index) and patient global impression of change scale. To investigate the biomechanical effect of foot orthoses, in-shoe foot kinematics and plantar pressures were evaluated at 12 weeks. Of the 119 participants screened, 37 were randomised and 33 completed the study (FFO = 18, sham = 15). Compliance with foot orthoses and blinding of the intervention was achieved in three quarters of the group. Both groups reported improvements in pain, function and global impression of change; the FFO group reporting greater improvements compared to the sham group. The biomechanical outcomes indicated the FFO group inverted the hindfoot and increased midfoot maximum plantar force compared to the sham group. The present findings suggest FFOs worn over 12 weeks may provide detectable clinical and biomechanical benefits compared to sham orthoses. This feasibility study provides useful clinical, biomechanical and statistical information for the design and implementation of a definitive randomised controlled trial to evaluate the effectiveness of FFOs in treating painful midfoot OA.Electronic supplementary materialThe online version of this article (doi:10.1007/s10067-015-2946-6) contains supplementary material, which is available to authorized users.

Effectiveness of foot orthoses and shock-absorbing insoles for the prevention of injury: a systematic review and meta-analysis

“…However, trials that did not use a control insole may be affected by methodological issues that may confound or bias the findings, such as placebo effect, ascertainment bias and resentful demoralisation 29. Trials that used a control insole may have mitigated these issues, but this is difficult to determine as no trial measured whether participant blinding was successful,51 whether the interventions were perceived as credible,52 or indeed, whether the control interventions had mechanical or physiological effects 50 52…”

Chronic foot pain in older people

“…In relation to symptoms, two uncontrolled studies have suggested that foot orthoses can reduce foot pain in older people [85,86], and one randomised controlled trial found that foot orthoses with a medial arch support and metatarsal pad were effective at reducing foot pain and foot-related disability in older women with osteoporosis [87]. More recently, two randomised trials found that foot orthoses were effective at reducing symptoms in people with osteoarthritis of the first metatarsophalangeal joint [88] and midfoot joints [89]. These studies suggest that foot orthoses may be a useful conservative treatment for a range of foot disorders in older people.…”

Comparability of off the shelf foot orthoses in the redistribution of forces in midfoot osteoarthritis patients

“…In people with midfoot OA, short-term non-randomised studies demonstrated functional foot orthoses (FFO) improve pain and function [20] , [21] . Similarly, a recent feasibility study demonstrated that midfoot OA participants randomly assigned to the FFO group reported significantly greater improvements in clinical and functional outcomes compared to a sham intervention group [22] . Taken together, these findings suggest increased forces and/or pressures acting on the midfoot may contribute to increased mechanical loading on joints, and FFOs may support these structures thereby reducing pain and improving function.…”