The efficacy of foot orthoses in individuals with patellofemoral osteoarthritis: a randomised feasibility trial

Abstract

Background Foot orthoses have the potential to be an efficacious treatment for patellofemoral osteoarthritis (PFOA) but have not been evaluated in clinical trials in this population. This study aimed to determine the: (i) feasibility of conducting a randomised controlled trial (RCT) investigating the efficacy of foot orthoses in individuals with PFOA; and (ii) effects of foot orthoses versus flat shoe inserts on pain, function, and knee-related quality of life (QOL). Methods This 6-week, single-blinded pilot RCT randomly allocated participants with PFOA to receive foot orthoses or flat inserts. The primary outcome of feasibility was determined via the following parameters: one participant recruited per week, 20% (35 h/week) adherence to the intervention, 50% log book completion rate, and < 20% drop-out, with results reported using descriptive statistics. Secondary outcomes included average and maximum pain severity (100 mm visual analogue scale), Anterior Knee Pain Scale, and Knee injury and Osteoarthritis Outcome Score, analysed using analysis of covariance. Results Twenty-six participants (16 women; mean (SD) age of 60 (8) years) with PFOA were recruited. All feasibility parameters were exceeded, with three participants recruited per week, > 20% (37.2 [9.8] hours/week) adherence to the intervention, 69.2% (18/26) log-book completion, and 3.8% (1/26) drop-outs. The most common adverse events were arch irritation and shoe fit issues, which were more common in the foot orthoses group (67.9% versus 32.1%). There was a trend for the foot orthoses group to report larger improvements in average and maximum pain than the flat insert group, with the mean difference for maximum knee pain severity (21.9 mm, 95% CI − 2.1 to 46.0) exceeding the minimal clinically important difference (15 mm). The estimated sample size for a full-scale RCT is 160 participants. Suggestions to improve study design include a greater number of face-to-face follow-up appointments, a larger variety of foot orthoses to reduce rates of adverse events, and increasing follow-up time to determine long-term efficacy. Conclusion This study supports the feasibility of a full-scale RCT to determine the efficacy of foot orthoses versus flat inserts in individuals with PFOA. Trial registration The trial protocol was retrospectively registered with the Australian and New Zealand Clinical Trials Registry (ANZCTR number: 12616001287426 ).

Associations of foot and ankle characteristics with knee symptoms and function in individuals with patellofemoral osteoarthritis

“…addressing greater midfoot flexibility) [ 51 ]. This is supported by previous studies that have demonstrated that individuals with PFOA respond favourably to foot orthoses and/or footwear immediately [ 44 , 52 ], and in the short-term (6 weeks) [ 46 ]. However, future trials are now required to determine if such interventions are effective in isolation versus being a part of a multimodal treatment plan.…”

“…Higher FPI (indicative of a more pronated foot posture) was significantly associated with fewer repeated single step-ups and double-leg sit-to-stands to knee pain onset. Foot pronation has previously been highlighted as being associated with PFP [ 13 , 15 ] and may therefore influence the efficacy of in-shoe interventions in this population [ 43 ], with recent studies providing preliminary evidence that foot orthoses may be an effective treatment in individuals PFOA [ 44 – 46 ]. One of the proposed mechanisms is that foot pronation, leading to internal tibial and femoral rotation, causes either a decrease in PFJ contact area or an increase in PFJ reaction forces, thereby elevating PFJ loads [ 19 ].…”

Management of patellofemoral joint osteoarthritis using biomechanical device therapy: a systematic review with meta-analysis

“…Two studies ([ 14 ] (n=30) [ 15 ]; (n=106)) assessed some of the participants from a parent trial ([ 13 ], n=126). Tan et al [ 23 ] was a biomechanical study nested within a pilot RCT [ 22 ]. Two studies did not provide information on the sex of the participants (Kumar & Ganesh 2011 [ 20 ];), so excluding these, the overall percentage of females (62%) was greater than males though there was wide variation in the proportion of males and females between the studies (males 14–45% and females 55–86%).…”

Exercise-therapy and education for individuals one year after anterior cruciate ligament reconstruction: a pilot randomised controlled trial

“…The sample size of 27 was not formally determined. It was based on previous pilot RCTs evaluating health-professional guided interventions for musculoskeletal conditions (41,67), and deemed su cient to assess the feasibility criteria. Participants who completed baseline and follow-up evaluations were included in the analysis, as recommended in the CONSORT guidelines (48).…”