Comparative outcomes of foot cast and short leg cast in pseudo-Jones avulsion fracture: a single blinded randomized controlled trial

BACKGROUND: Fractures of the metatarsal bones account for 35% of all foot fractures. Conservative management of fractures proximal to the metaphyseal-diaphyseal junction of the fifth metatarsal bone (pseudo-Jones) is by protected weight bearing. The methods of protected weight bearing include short-leg casting and splinting (boot cast, Jones’s bandage and elastic bandage). However, currently there is no consensus as to which method is the most suitable. METHOD: We have conducted a randomized controlled trial to compare outcomes of foot casting (FC) and short leg casting (SLC) to assess pain, function and complication outcomes for the treatment of pseudo-jones metatarsal fractures. This single-center, single blind,randomized controlled trial was conducted between 1 June 2016–1 July 2018 at Police General Hospital, Bangkok, Thailand. RESULT: A total of 72 pseudo-jones metatarsal fracture participants were randomly allocated to treatment by foot cast or short leg cast. The primary outcomes were pain VAS, AOFAS and complications measured at 2, 4, 6 and 8 weeks after receiving the treatment. Seventy-two patients (36 paticipants per group) were enrolled to receive either FC or SLC. The mean VAS measured at baseline, 2 weeks, 4 weeks, 6 weeks and 8 weeks were 7.36, 1.97, 0.58, 0.17 and 0.08 respectively in the FC group; and 6.09, 2.91, 1.23, 0.37 and 0.11 respectively in the SLC group. The mean AOFAS at baseline, 2, 4, 6 and 8 weeks were 33.60, 68.22, 82.72, 91.75 and 98.11 respectively in the FC group; and 32.60, 60.20, 70.20, 92.24 and 99.13 in the SLC group. The estimated mean difference of pain VAS and AOFAS at 2 weeks and 4 weeks were − 0.94 (95% CI: − 1.53, − 0.34), − 0.65 (95%CI: − 1.24, − 0.05), 8.02 (95%CI: 3.74, 12.10) and 12.52 (95%CI: 8.27, 16.78), which were statistically significantly better in the FC groups when compared to the SLC groups. However, there were no statistically significant difference between the two groups at 6 and 8 weeks. CONCLUSION: This study demonstrated that the application of foot casting can improve pain VAS and AOFAS function at 2 and 4 weeks in the treatment of pseudo-jones metatarsal fractures when compared to short leg casting. However, at 6 and 8 weeks, there were no statistically significantly different between the two groups.