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Abnormal triangular epiphysis causing angular deformity of the thumb

Goo Hyun Baek1, Moon Sang Chung, Hyun Sik Gong

  • 1Department of Orthopedic Surgery, Seoul National University College of Medicine, Chongno-gu, Seoul, Korea. ghbaek@snu.ac.kr

The Journal of Hand Surgery
|April 25, 2006
PubMed

Insights

Abnormal triangular epiphysis in the thumb can cause angular deformity. Corrective closing-wedge osteotomy, particularly intraepiphyseal, effectively corrects this thumb deformity with good patient satisfaction.

Area of Science:

  • Orthopedic surgery
  • Pediatric orthopedics
  • Hand surgery

Background:

  • Abnormal triangular epiphysis of the distal phalanx is a rare condition causing angular deformity in the thumb.
  • This condition requires surgical intervention for correction.

Purpose of the Study:

  • To describe the triangular-shaped abnormal secondary ossification center of the distal phalanx.
  • To evaluate the surgical outcome of corrective closing-wedge osteotomy for thumb angular deformity.

Main Methods:

  • Retrospective review of 6 patients (9 thumbs) with abnormal triangular epiphysis.
  • Surgical procedures included intraepiphyseal or proximal phalangeal closing-wedge osteotomy.
  • Measurements of angular deformity and interphalangeal (IP) joint range of motion (ROM) were taken pre- and post-operatively.

Main Results:

  • Preoperative ulnar deviation averaged 30 degrees, reduced to 12 degrees post-surgery.
  • All osteotomies healed without physeal or articular damage.
  • IP joint ROM was maintained, with high patient and parent satisfaction.

Conclusions:

  • Abnormal triangular epiphysis is distinct from delta bone and treatable with closing-wedge osteotomy.
  • Intraepiphyseal osteotomy demonstrated superior deformity correction compared to proximal phalangeal osteotomy.
Abstract

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