Treatment of proximal interphalangeal dorsal fracture-dislocation injuries with dynamic external fixation: A pins and rubber band system

Purpose: Unstable, dorsal, intra-articular, fracture-dislocations of the proximal interphalangeal (PIP) joint can be difficult to treat and often lead to long-term pain, stiffness, and functional deficit. We present the outcomes of patients sustaining such injuries that were treated by a novel dynamic external fixator. This fixator uses a system of K-wires and rubber bands that maintains a concentrically reduced PIP joint while allowing for early motion. Methods: Fourteen patients with unstable, dorsal fracture-dislocation injuries of the PIP joint were treated between September 2001 and January 2006. Eight were available for follow-up evaluation at an average of 26 months. We measured PIP range of motion and grip strength, and assessed pain on a visual analog scale. Demographic information about the original injury was recorded. New radiographs were obtained to assess joint congruency and the presence of arthritis or articular step-off deformity. Results: In the 8 patients available for follow-up evaluation, the average motion of the affected PIP joint was from 1 degrees (range 0 degrees to 5 degrees) to 89 degrees (range 75 degrees to 110 degrees). Grip strength was 92% (range 71 % to 110%) of the unaffected hand. The average score on the visual analog pain scale was 0.6 (range 0-1.5). There were few complications. Radiographs at follow-up evaluation showed a concentric reduction in all joints, but with evidence of a small step-off deformity or arthritis in 5 patients. Conclusions: The dynamic external fixator studied is an effective method of treating unstable, dorsal fracture-dislocation injuries. Outcomes compared favorably with those of other similar devices studied in the literature.