TIBIA FRACTURES PRODUCED FROM THE IMPACT OF A BASEBALL BAT

Forty-seven patients presented during a 1-year period with fractures o f the extremities produced by the impact of a baseball bat. This repre sented an increase of fourfold in fractures associated with baseball b at trauma as compared with the previous year. Those patients with tibi a fractures were retrospectively reviewed in terms of associated soft- tissue injuries, fracture pattern, and fracture healing. Potential for ce generated and kinetic energy transferred when a baseball bat strike s the tibia were calculated mathematically to provide correlation with clinical observations. Tibia fractures produced by baseball bats repr esented 10% of all tibia fractures presenting from July 1990-July 1991 . Of these 11 tibia fractures, 3 developed compartment syndrome, neces sitating fasciotomy and subsequent skin grafting, and 1 developed oste omyelitis, which eventually resulted in amputation. One patient had su perficial skin blistering that required a delay in definitive fracture care of 11 days and subsequent skin grafting. There was one nonunion and three delayed unions requiring additional operative intervention. This incidence of compartment syndrome (27%) is nine times higher than the overall incidence, at this institution, of compartment syndrome ( 3%) in tibia fractures produced by other mechanisms. The maximum poten tial kinetic energy produced during the impact of a baseball bat is 51 5 kg/m2/s2: 25% higher than that produced by a 9-mm bullet fired at a distance of 6 ft (407 kg/m2/s2). The potential force transmitted from a bat to the tibia at the time of collision is 8,000 lb, three times t hat of the bullet (626 lb). The unusually high incidence of soft-tissu e complications associated with this particular mechanism may be attri buted to the fact that these are high-energy injuries with a large amo unt of force transmitted to a broad area of soft tissue. One must be a ware not only of the hard-tissue trauma in tibia fractures produced by baseball bats, but also of the potential for soft-tissue compromise.