Local osteopenia associated with management of intra-articular distal radial fractures by insertion of external fixation pins in the distal fragment: prospective study.

PURPOSE To assess the restoration of the bone mass of the distal radius following the use of implants in the distal radial fragment. Highly comminuted Frykman type 7 and 8 fractures were studied to determine whether the use of fixation pins in the comminuted distal radial fragment leads to osteopenia in the distal radial fragment after healing of the fracture. METHODS As part of a clinical trial, 30 patients with comminuted intra-articular fractures of the distal radius were treated with closed reduction, external non-bridging fixation, and early postoperative mobilisation. To detect local osteopenia, bone density measurements were taken at the distal metaphysis and mid-diaphysis following healing of the fractured radius and the contralateral unaffected radius in 12 patients. RESULT The mean age of the 12 patients for whom bone density measurements were recorded was 52.5 years (range, 39-87 years). There were 9 females and 3 males included in the study. Seven patients had a Frykman type 8 fracture and 5 patients had a Frykman type 7 fracture. Significant osteopenia was absent despite the use of four 2.5-mm fixation pins in the distal fragments of the healed distal radial fracture. The median value of the maximal step was 2.8 mm (range, 0-9.1 mm). The median value of the intra-articular interfragmentary gap was 1.8 mm (range, 0-13.4mm). CONCLUSION The findings of this study do not suggest long-term osteopenia following the use of four 2.5-mm pins in the distal fragments. The non-bridging fixator, by allowing early physical activity, possibly led to satisfactory functional and structural results.