Metatarsal length in metatarsalgia: does size matter?

J. Carter, J. Alsousou, M. Almutani, S. Sirikonda

Introduction: Maestro's arc has proven an invaluable tool when planning surgical correction of metatarsal (MT) length in the treatment of metatarsalgia (MTA). But 20% of patients remain symptomatic are we being presumptuous in thinking that the MT arcade is universal? We propose a study to answer the following questions. Is the Maestro arc applicable to our population? Is there a significant difference in MT lengths when comparing those with and without metatarsalgia? Are there other significant factors responsible?

Methods: Data collection was retrospective, plain radiographs and clinical notes were reviewed for elective foot and ankle clinic attendences between 2012 and 2014. Exclusion criteria were hallux valgus angle over 150, previous surgery and gross deformity. Data analysis: parametric tests showed non-parametric data. Means were compared using Mann Whitney test for bivariable and Kurskal-Wallis tests for multivariants groups. Graphpad Prisme 5.0 software was used and 5% p value was considered significant.

Results: 173 patients were analysed (140 without MTA & 33 with MTA). Overall relative MT lengths were different between the two groups (p< 0.01). Dunn's post-test to compare the metatarsal length-difference between the same metatarsals in the two groups showed significant difference between 1-2 MT, 3-4MT and 4-5 MT (P was 0.025, 0.024 and 0.01 respectively). There was no difference in the 2-3 MT length (p 0.241). There was no difference between the two groups in HVA (p=0.66). Females had significantly higher risk of MTA when compared with males (p=0.015).

Conclusions: Respective metatarsal length is significant in metatarsalgia - size does matter. Female gender was also found to be associated. Our cross section of 'normal' feet without metatarsalgia yielded an arc of metatarsal lengths significantly different to maestro's arc. This may suggest we need to rethink our pre-operative planning.