The Syringe External Fixator: Short- and Medium-Term Functional Outcomes From This Inexpensive and Customizable Treatment for Comminuted Intra-Articular Fractures of the Hand

Purpose: Comminuted intra-articular fractures and fracture dislocations of the metacarpophalangeal (MCP) and interphalangeal joints are challenging. Dynamic external fixation, permitting early joint motion while still minimizing forces across the healing joint, can result in acceptable postoperative active range of motion (AROM). However, some fractures are not initially stable enough for early dynamic motion; further, many available dynamic external fixation systems are costly and cumbersome. We reviewed our experience using an external fixator made from a 1-mL syringe and K-wires and report outcomes using it as a static fixator, dynamic fixator, or configured as a static fixator and then converted to a dynamic fixator in the clinic.

Methods: Patients with intra-articular fractures and fracture dislocations of the MCP and proximal interphalangeal (PIP) joints treated between 2014 and 2020 using syringe external fixators were retrospectively reviewed. We reviewed demographics, mechanisms, treatment types and durations, and postoperative AROM, as well as complications including infection, pin loosening, nonunion, hardware failure, and need for further surgery. Patients were analyzed by the level of joint injury (MCP versus PIP) and by treatment pattern.

Results: After excluding 23 patients with 25 joint injuries who were lost to follow-up or had inadequate outcome data, 27 patients with 29 joint injuries were reviewed. The average follow-up was 171 days after surgery. The postoperative AROM at the MCP level averaged 55° for static fixation and 30° for static-to-dynamic fixation. The postoperative AROM at the PIP level averaged 64° for static fixation, 66° for static-to-dynamic fixation, and 80° for dynamic fixation. Three pin site infections and 2 loose pins were reported.

Conclusions: The syringe external fixator is an inexpensive, effective, and customizable treatment for intra-articular MCP and interphalangeal fractures and fracture dislocations, and results in acceptable postoperative AROM outcomes and complication rates.

Type of study/level of evidence: Therapeutic IV.