Open Reduction and Internal Fixation of Dorsal Fracture-Dislocation of the Distal Interphalangeal Joint Using a Low-Profile Mini-Plate: A Report of Three Cases.

Although dorsal fracture-dislocations of the distal interphalangeal (DIP) joints of the fingers are relatively rare injuries, if left untreated, functional disabilities of the DIP joints persist. Thus, reducing the dislocation and reconstructing the articular surface at the base of the distal phalanx is crucial to allow early DIP joint motion. This study evaluates the outcomes of three patients with dorsal fracture-dislocations of the DIP joints. Two patients had a split-depression type fracture and one had an impaction type fracture, and articular involvement averaged 55.7%. They were treated with open reduction and internal fixation using a low-profile mini-plate. Dorsal instability of the DIP joint is stabilized with an extension block pin inserted into the middle phalangeal head, followed by plate fixation with the palmar approach of the distal phalanx. One patient had a concomitant dorsal fracture-dislocation of the proximal interphalangeal joint of the same finger which was treated by the same procedure. The average time from injury to surgery was 6.6 days. Postoperative outcomes were evaluated with joint motion, grip strength, Quick Disabilities of Arm, Shoulder and Hand (DASH) questionnaire score as patient-based assessment, and plain radiographs. Strickland's scoring scale (Strickland's score) was used to evaluate total active motion. The mean postoperative follow-up was 18.6 months. The mean postoperative DIP joint motion was 0° on extension and 71.3° on flexion, and the mean % total active joint motion was 98.3%, and Strickland's score was excellent in all cases. Grip strength was 107.7% compared to the unaffected side. The mean Quick DASH score was 3.03 points. This study suggests that volar mini-plate fixation is an effective surgical technique for this injury, as it rigidly secures the bone fragment between the plate and the dorsal bone cortex allowing for early postoperative joint motion.