Open Reduction and Internal Fixation of Dorsal Fracture-Dislocation of the Proximal Interphalangeal Joint Using a Plate: A Series of 37 Patients.

Background: Open reduction and internal fixation with a plate is one of the alternative treatments for fracture-dislocation of the proximal interphalangeal (PIP) joint. However, it does not always lead to satisfactory results. The aim of this cohort study is to describe the surgical procedure and discuss the factors affecting the treatment results. Methods: We retrospectively reviewed 37 cases of consecutive unstable dorsal fracture-dislocation of the PIP joint treated using a mini-plate. The volar fragments were sandwiched with a plate and dorsal cortex, and screws were used as subchondral support. The average rate of articular involvement was 55.5%. Five patients had concomitant injuries. The mean age of the patients was 40.6 years. Mean time between injury and operation was 11.1 days. The average postoperative follow-up duration was 11 months. Active ranges of motion, % total active motion (TAM) were evaluated postoperatively. The patients were divided into two groups according from Strickland score and Gaine score. Fisher's exact test, Mann-Whitney U test and a logistic regression analysis were used to evaluate the factors affecting the results. Results: The average active flexion, flexion contracture at the PIP joint, and % TAM were 86.3°, 10.5° and 80.6%, respectively. Group I included 24 patients who had both excellent and good scores. Group II included 13 patients who had neither excellent nor good scores. When the groups were compared, there was no significant relationship between the type of fracture-dislocation and the extent of articular involvement. There were significant associations between outcomes and patient age, period from injury to surgical intervention and presence of concomitant injuries. Conclusions: We concluded that meticulous surgical technique leads to satisfactory results. However, factors, including the patient's age, time from injury to surgery and the presence of concomitant injuries needing adjacent joint immobilisation, contribute to unsatisfactory outcomes. Level of Evidence: Level IV (Therapeutic).