Joint distraction and early mobilization using a new dynamic external finger fixator for the treatment of fracture-dislocations of the proximal interphalangeal joint.

BACKGROUND: Dynamic external fixation is a useful treatment option for unstable fracture-dislocations of the proximal interphalangeal (PIP) joint, because it simultaneously reduces axial pressure load on the joint surface, maintains congruent joint reduction, and permits early joint motion. However, most current devices are large, hindering finger movement, and unstable. To address these problems, we developed a dynamic external finger fixator, named the Micro Ortho Fixator® . The purpose of this study was to review the results of using the new external finger fixator to treat unstable fracture-dislocations of the PIP joint.

MATERIALS AND METHODS: Nine patients who sustained unstable fracture-dislocation injuries of the PIP joint were treated with the Micro Ortho Fixator® . Seven fractures were accompanied by depressed bony fragments at the base of the middle phalanx. All patients were evaluated for pain and range of PIP motion at the final follow-up. Radiographs of the affected fingers were evaluated for PIP congruity and reduction. The mean follow-up duration was 11.1 months (range: 6-33 months).

RESULTS: At the final follow-up, pain averaged 0.3 (range: 0-2) on the Numeric Pain Rating Scale, and the total arc of motion at the PIP joint averaged 91.2° (range: 50-110°). All fractures had healed, and the intra-articular step-off improved from 1.9 mm (SD: 1.0) before surgery to 0.2 mm (SD: 0.4) at the final follow-up. The patients who sustained sports injuries returned to competition after an average of 3.5 months (range: 2.5-4 months).

CONCLUSION: The external fixator is compact and facilitates range-of-motion (ROM) exercises, has high stability, and achieves good joint congruity and an ROM equivalent to the healthy joint of the patient.

STUDY DESIGN/LEVEL OF EVIDENCE: Therapeutic/IV.