Hyperbaric oxygen in the treatment of acute muscle stretch injuries. Results in an animal model.

Hyperbaric oxygen therapy is an established therapy in several areas of clinical medicine. However, studies have produced conflicting results regarding its efficacy for sports-related soft tissue injuries. This study examines the use of hyperbaric oxygen therapy after an acute muscle stretch injury in an animal model. Two groups of rabbits (nine in each group) were subjected to a partial stretch injury to the tibialis anterior muscle-tendon unit. For all 18 animals, the injuries were induced in the left limb, and the uninjured right limb served as a sham-operated control. In group 1, the animals were exposed to hyperbaric oxygen (> 95% O2 at 2.5 atm) for 60 minutes daily for 5 days. Treatment began 24 hours after injury. Group 2 animals were not exposed to hyperbaric oxygen. Evaluation 7 days after injury demonstrated a functional deficit (percent ankle isometric torque; injured side versus uninjured side) of 14.9% +/- 5.5% (mean +/- SD) for the treated group and 47.5% +/- 5.4% for the untreated group, representing a statistical difference using the Behrens-Fisher version of the t test (P = 0.001). Morphologic studies revealed more complete healing in the treated group. This study suggests that hyperbaric oxygen therapy may play a role in accelerating recovery after acute muscle stretch injury. Further studies are needed before definitive conclusions and treatment recommendations can be made.