Shoe-stiffening inserts for first metatarsophalangeal joint osteoarthritis: a randomised trial.

OBJECTIVE: To evaluate the efficacy of carbon-fibre shoe-stiffening inserts in individuals with first metatarsophalangeal joint osteoarthritis. DESIGN: This was a randomised, sham-controlled, participant- and assessor-blinded trial. One hundred participants with first metatarsophalangeal joint osteoarthritis received rehabilitation therapy and were randomised to receive either carbon fibre shoe-stiffening inserts (n = 49) or sham inserts (n = 51). The primary outcome measure was the Foot Health Status Questionnaire (FHSQ) pain domain assessed at 12 weeks. RESULTS: All 100 randomised participants (mean age 57.5 (SD 10.3) years; 55 (55%) women) were included in the analysis of the primary outcome. At the 12 week primary endpoint, there were 13 drop-outs (7 in the sham insert group and 6 in the shoe-stiffening insert group), giving completion rates of 86 and 88%, respectively. Both groups demonstrated improvements in the FHSQ pain domain score at each follow-up period, and there was a significant between-group difference in favour of the shoe-stiffening insert group (adjusted mean difference of 6.66 points, 95% CI 0.65 to 12.67, P = 0.030). There were no between-group differences for the secondary outcomes, although global improvement was more common in the shoe-stiffening insert group compared to the sham insert group (61 vs 34%, RR 1.73, 95% CI 1.05 to 2.88, P = 0.033; number needed to treat 4, 95% CI 2 to 16). CONCLUSION: Carbon-fibre shoe-stiffening inserts were more effective at reducing foot pain than sham inserts at 12 weeks. These results support the use of shoe-stiffening inserts for the management of this condition, although due to the uncertainty around the effect on the primary outcome, some individuals may not experience a clinically worthwhile improvement.

Foot structure and lower limb function in individuals with midfoot osteoarthritis: a systematic review.

OBJECTIVE: To determine how foot structure and lower limb function differ between individuals with and without midfoot osteoarthritis (OA). DESIGN: Electronic databases were searched from inception until May 2020. To be eligible, studies needed to (1) include participants with radiographically confirmed midfoot OA, with or without midfoot symptoms, (2) include a control group of participants without radiographic midfoot OA or without midfoot symptoms, and (3) report outcomes of foot structure, alignment, range of motion or any measures of lower limb function during walking. Screening and data extraction were performed by two independent assessors, with disagreements resolved by a third independent assessor. The methodological quality of included studies was assessed using the National Institutes of Health Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. RESULTS: A total of 1,550 records were screened by title and abstract and 11 met the inclusion criteria. Quantitative synthesis indicated that individuals who had midfoot OA had a more pronated foot posture, greater first ray mobility, less range of motion in the subtalar joint and first metatarsophalangeal joints, longer central metatarsals and increased peak plantar pressures, pressure time integrals and contact times in the heel and midfoot during walking. Meta-analysis could not be performed as the data were not sufficiently homogenous. CONCLUSIONS: There are several differences in foot structure and lower limb function between individuals with and without midfoot OA. Future research with more consistent case definitions and detailed biomechanical models would further our understanding of potential mechanisms underlying the development of midfoot OA.