Prevention of Equinus Deformity after External Fixation for Open Tibia Fractures: A Comparison between Plaster of Paris Backslab and Passive Ankle Physiotherapy.

Background: Ankle equinus deformity is a common complication of prolonged external fixator use in tibia fractures with an incidence of 15%-16%. It affects gait and may lead to foot, leg, and back problems. Treatment of equinus deformity increases the cost of treatment of open tibia fractures and increases the time spent off work. Several preventive modalities have been suggested in literature with variable success, but no standard protocol exists.

Objectives: The aim of this study was to determine the most appropriate method of preventing equinus deformity of the ankle joint during the management of open tibia fractures with unilateral uniplanar external fixators by comparing plaster of paris (POP) backslab application with passive ankle physiotherapy using strips of car tyre inner tubing.

Materials and methods: The study was a prospective randomised study involving patients with open tibia fractures who were managed with external fixators at the Korle Bu Teaching Hospital between April 2020 and February 2021. Patients were randomised into two groups; one group had below knee POP backslab and the other group did passive ankle physiotherapy using a strip of car tyre inner tubing. The passive ankle range of motion was measured at the beginning and after 6 weeks using a goniometer.

Results: Fifty-six participants were recruited with 29 in the POP backslab group and 27 in the ankle physiotherapy group. The median age was 35.0 years. Male-to-female ratio was 4.6:1. Motor vehicle crash contributed to over 90% with 42.9% being motorbike riders. Initial and final mean ankle measurements for the POP backslab group were 6.79° and 10.14° for dorsiflexion and 29.93° and 34.52° for plantarflexion, respectively. The ankle physiotherapy group had initial and final dorsiflexion of 7.19° and 12.85° and plantarflexion of 30.44° and 34.52°, respectively. The ankle physiotherapy group had a better range of motion (47.37°) than the POP group (40.66°) with a P value of 0.008. One participant (3.7%) from the ankle physiotherapy group had equinus deformity compared with seven (24%) from the POP backslab group, a difference which gives a P value of 0.029.

Conclusions: Passive ankle physiotherapy with car tyre inner tube is a better and cheaper modality of preventing ankle equinus deformity and maintaining ankle range of motion.