Salter-Harris type IV fracture of the proximal phalanx of the thumb with rotation of the epiphysis: Outcome 10 years following open reduction and K-wire fixation.

INTRODUCTION: Salter-Harris type IV fracture of the proximal phalanx with 90° rotation of the epiphysis is very rare. We report on a case of Salter-Harris type IV fracture of the proximal phalanx of the thumb with rotation of the epiphysis and document the outcome 10 years after surgery.

PRESENTATION OF CASE: A 5-year old boy presented with Salter-Harris type IV fracture of the thumb with 90° rotation of the epiphysis. Open reduction and K-wire fixation was done. Ten years later, the injured thumb was smaller in width when compared to the contralateral thumb, although there was no length discrepancy. Clinically, there was full range of motion. Radiologically, the physis was still open but there were minor irregularities at the adjacent metaphyseal base and epiphysis. The diaphysis of the injured proximal phalanx had a constricted appearance when compared to the contralateral normal side.

DISCUSSION: After an extensive literature review, we found one reported case which was similar to our case and had long term assessment. At skeletal maturity, there was complete remodeling and full range of motion of the digit with no shortening. The X-ray showed a constricted diaphysis of the proximal phalanx with an identical appearance to our case.

CONCLUSION: We present a rare case of Salter-Harris type IV fracture of the proximal phalanx of the thumb with rotation of the epiphysis. Long term outcome was satisfactory but there was diaphyseal constriction leading to a narrower thumb.