Goo Hyun Baek MD1, 2, , , Moon Sang Chung MD1, 2, Hyun Sik Gong MD1, 2, Sanglim Lee MD1, 2, Young Ho Lee MD1, 2 and Hyoung Ho Kim MD1, 2
1Department of Orthopedic Surgery, Seoul National University College of Medicine, Seoul, Korea 2Department of Orthopedic Surgery, Sanggye Paik Hospital, Seoul, Korea
To present a triangular-shaped abnormal secondary ossification center of the distal phalanx causing angular deformity of the thumb and the surgical outcome of corrective closing-wedge osteotomy for this deformity.
Methods We treated 6 patients with abnormal triangular epiphysis in the distal phalanx of the thumb, including 3 bilateral cases. The average age was 43 months and there were 2 boys and 4 girls. Of the 9 thumbs intraepiphyseal closing-wedge osteotomy was performed in 5 and proximal phalangeal closing-wedge osteotomy was performed in 4. We measured the deformities in degrees of angulation and the range of motion of the interphalangeal (IP) joint. The average duration of the follow-up period was 27 months after the surgery.
Results Preoperative angular deformity of ulnar deviation averaged 30°, which was reduced to an average of 12° after osteotomy at the last follow-up assessment. All osteotomies healed and there was no evidence of physeal or articular damage. Interphalangeal joint range of motion did not decrease after surgery in all cases. Patients and parents were satisfied with the results of the surgery, although mild deformity persisted in the interphalangeal joint when in the flexed position after proximal phalangeal osteotomy.
Conclusions Abnormal triangular epiphysis causing angled thumb is different from delta bone and can be treated with either intraepiphyseal or proximal phalangeal closing-wedge osteotomy. The intraepiphyseal procedure, however, could achieve better deformity correction regardless of the interphalangeal joint position.
The Journal of Hand Surgery. Volume 31, Issue 4 , April 2006, Pages 544-548.