Early controlled passive motion improves early fracture alignment and structural properties in a closed extra-articular metacarpal fracture in a rabbit model.

Purpose: To investigate if early controlled passive mobilization was likely to cause harm with regard to affecting the quality and rate of early fracture healing in a closed, potentially unstable, diaphyseal fracture in a rabbit model.

Methods: This was a preclinical, block-randomized, single-blind efficacy trial examining 3 time periods (baseline [day 5], day 14, day 28) and 2 treatment conditions (immobilization, passive motion). Fifty mature, female, New Zealand white rabbits were preconditioned to a non-weight-bearing brace before creating a closed third metacarpal fracture.