Tibial fracture stability. Analysis of external fracture immobilization in anatomic specimens in casts and braces

Plaster casts, custom-fabricated fracture braces, and prefabricated fracture braces were compared in the laboratory for the stability they provided to closed, experimental, diaphyseal fractures of the tibia and fibula on anatomic specimens. The stability was comparable for each type of device tested for the loading conditions of isolated compression, bending, and torsion. Length stability (overriding at the fracture site) was poor, rotation was marginal (by clinical standards), and angulation was very good. Selective removal of portions of each cast and brace demonstrated that the classic patellar-tendon-bearing (PTB) extension proximally and below ankle extensions distally had insignificant effects on stability of these middle-third diaphyseal fractures for the conditions tested. The soft-tissue compression provided by a snug, tapered "cylindrical" sleeve, which encompassed the soft tissues from the tibial tubercle to the flare of the distal tibia and fibula, provided the stabilizing effect for all of the devices tested.