Patterns of proximal interphalangeal joint dislocations

INTRODUCTION: The aim of the study was to understand finger proximal interphalangeal joint (PIPJ) dislocations better by reviewing the demographics and biomechanics of a cohort of PIPJ dislocations. METHODS: All cases of PIPJ dislocations presenting to our emergency department or neighbouring minor injury units over a 2 year period were reviewed. We recorded demographics, mechanism of injury, direction of the dislocation radiologically, concomitant injuries and rates of follow-up (FU). RESULTS: There were 74 dislocations in 74 adults with a median age of 46 (range 14-87) years. Fifty-six (76%) were men and 18 (24%) were women. The dislocations were ulnar more than radial: little finger (43%), ring finger (34%), middle finger (15%) and index finger (8%). Amongst all 74 dislocations, 36 (49%) were dorso-ulnar, 30 (41%) dorsal, five (7%) ulnar, two volar and one dorso-radial. Six dislocations were open. Five of these were dorsal dislocations and five affected the index (three) and middle (two) fingers. The median number of FU appointments was two (range 0-21). CONCLUSION: Our findings suggest that PIPJ dislocations commonly affect two distinct populations: young men suffering little finger dislocations during sport and older patients sustaining middle finger dislocations after falling. Open dislocations are predominantly dorsal dislocations of the index and middle fingers. FU rates are very variable but suggest 20% of cases have prolonged symptoms. LEVEL OF EVIDENCE: IV.