Effect of a Steel Toe Cap on Forefoot Injury Pattern in a Cadaveric Model

Abstract

Background: Crush injuries to the foot are a common workplace injury and a significant source of morbidity, disability and lost wages. Many regulatory bodies including the Occupational Safety and Health Administration (OSHA) recommend the use of safety shoes in certain occupations to help protect against these occupational hazards. However there remains controversy and paucity of published data regarding the protection afforded by a steel toe cap in regards to clinical injury pattern. This study looks to investigates the protective influence of a steel toe cap on crush injuries of the forefoot. Materials and Methods: Five non-osteoporotic paired cadaver lower extremities were appropriately fitted to a standard work boot. One foot of each pair was fitted into a steel toe capped boot (designated “ST” group) while the other foot was fitted into an identical version of the work boot but without the protective steel toe cap (designated “NST” group). Each foot was crushed using a custom designed rig with a load of 150 lb dropped from a calibrated height of 3 feet to the forefoot. X-rays were obtained to assess fracture location & comminution and stress fluoroscopy was used to assess for any ligamentous Lisfranc injury. Results: The NST group averaged 8.2 fractured bones per foot while the ST group averaged 3.6 fractured bones per foot ( p = 0.001). The NST group demonstrated significantly more metatarsal fractures (3.2 fractures/foot) versus the ST group (one fracture/foot) ( p= 0.020). The NST group demonstrated significantly more proximal phalanx fractures (4.2 fractures/foot) compared to the ST group (2.6 fractures/foot) ( p= 0.035). Middle and distal phalanx fractures were not significantly different between the two groups. A higher percentage of the bones fractured were deemed comminuted in the NST group (53.6%) versus the ST group (38.8%) although this did not reach statistical significance. Conclusion: This study demonstrated that the steel toe affords protective advantages in crush injuries to the foot in limiting the number and severity of metatarsal and proximal phalanx fractures. However the steel toe does not fully protect the forefoot from injury. Clinical Relevance: Crush injuries to the foot are a common workplace injury. Strict adherence to workplace safety standards may limit the severity of crush injuries to the foot and additional safety measures such as metatarsal guards should be considered when appropriate.