External Fixator Pin Placement in the Lower Extremity Without Fluoroscopy

External fixation is a critical method for temporizing musculoskeletal injuries. Limited guidance exists on how to achieve appropriate external fixator pin depth without image guidance. We sought to validate a standardized technique for placing external fixation pins in the lower extremity without fluoroscopy.

Adults undergoing external fixation of lower extremity injuries at a level I trauma center were prospectively enrolled over 12 months. A standardized technique was used for pin placement, and pins were placed by attendings or trainees at PGY2 to PGY6 levels. Complications related to pin placement were recorded and classified as major, potential major, or minor. Major complications included neurovascular injury, pin tract osteomyelitis, and septic arthritis. Potential major complications included soft-tissue pin placement, unicortical pins, deep pin overpenetration (≥26 mm), and pins placed within or near a fracture or joint. Minor complications included pin tract infections and shallow pin overpenetration (9 to 25 mm). "Successful" external fixation application was defined as placement without any major or potential major complications.

Thirty-seven constructs (101 pins) were included. A total of 36 constructs (97.3%) and 99 pins (98.0%) were placed successfully. No major complications were observed. Potential complications occurred in one construct (2.7%) in which two pins (2.0%) were placed unicortically. Minor complications occurred in two pins (2.0%) demonstrating shallow overpenetration. Most pins (n = 97; 96%) were placed bicortically without overpenetration. The mean overpenetration of bicortical pins was 3.2 ± 2.3 mm. Overpenetration depth decreased with increasing training levels and increasing experience with the technique.

Placement of pins without image guidance during external fixation of lower extremity injuries resulted in successful placement of 98% of pins and 97% of constructs. This straightforward, reproducible technique can be used by surgeons of varying skill levels and done to safely apply external fixation in settings that lack fluoroscopic capabilities.