Consequences of extensile lateral approach to the calcaneal fractures on balance and isokinetic strength of muscle groups crossing the ankle joint.

Background: Inherent characteristics of extensile lateral approach (ELA) for fixation of displaced intraarticular calcaneal fractures together with delayed or probably insufficient physical therapy programs may lead to weakness of the muscle groups crossing the ankle joint. Peroneal tendons might be involved more than others because of possible postoperative adhesions. The aim of this study was to evaluate the isokinetic strength of the muscle groups crossing the ankle joint and also to assess balance and functional ability in this group of patients.

Methods: Based on a pilot study, 23 patients undergone open reduction and internal fixation (ORIF) via ELA and 22 healthy subjects as the control group participated in this observational cross-sectional study. Patients more than 20 years of age with at least 12 months passed their unilateral closed intraarticular calcaneal fracture fixation without any postoperative complications like infection or wound dehiscence were included. Patients with history of concomitant lower extremity injury, spine trauma or surgery, cases underwent removal of calcaneal plates, and cases with neuromuscular or vestibular dysfunction were excluded. The outcome was assessed by isokinetic parameters such as peak torque, peak torque normalized to body weight, mean power and total work modified star excursion balance test, triple hop for distance test, and evertor-to-invertor (E/I) strength ratio. Isokinetic tests were performed at 60 and 120°/s.

Results: Greater strength was observed in all muscles in the control group at 60°/s (p < 0.05). Evertors and invertors were weaker in the operated group at 120°/s in comparison to the dorsiflexors and plantarflexors. Modified star excursion (p: 0.003) and triple hop tests (p: 0.001) were lower in the operated group. E/I ratio was not statistically significant between the two groups at 60°/s (p: 0.44) and 120°/s (p: 0.62).

Conclusions: Strength deficit in all muscle groups crossing the ankle joint, and not evertors in isolation, in addition to balance and functional impairments would be seen one year following ORIF of calcaneal fracture via ELA. A long-term rehabilitation program emphasizing different kinds of contraction at low and high speeds and balance training in these patients is highly recommended.