Results of Treatment of Delta Triphalangeal Thumbs by Excision of the Extra Phalanx.

BACKGROUND

We examined the long-term results of treatment of delta triphalangeal thumbs by excision of the delta ossicle alone with respect to range of motion (ROM), pain, and angulation at the interphalangeal (IP) joint.

METHODS

We retrospectively reviewed charts to identify patients who had Woods type I delta triphalangeal thumbs and underwent treatment by excision of the extra ossicle. Patients with >2 years' follow-up were then brought in for examination and radiographs.

RESULTS

We identified 21 thumbs in 14 patients. All patients with bilateral thumb involvement, except 1, had them treated at the same surgery. The average age at surgery was 22 months (range, 5 to 69 mo). Preoperatively, 2 patients had tip radial angulation, averaging 53 degrees. The other 19 thumbs were deviated tip ulnarly with an average preoperative angulation of 40 degrees (range, 20 to 85 degrees). All patients had pinning of the IP joint for an average of 4.5 weeks (range, 3 to 9 wk), and 14 thumbs had collateral ligament repair. We obtained follow-up data >2 years on 14 thumbs in 10 patients. The average follow-up was 6.7 years (range, 2 to 17 y). Average ROM at final follow-up was <-4-degree extension (range, -20 to 0 degrees) to 56-degree flexion (range, 30 to 82 degrees). Average clinical angulation was <1 degree (range, 0 to 10 degrees) and the average radiographic angulation was 7 degrees (range, 0 to 25 degrees). No degenerative changes were noted. There were no complaints of pain and 1 patient had persistent IP instability. No other surgeries had been performed on the affected thumbs and there were no other complications.

CONCLUSIONS

Delta triphalangeal thumbs treated by excision of the extra ossicle can be expected to yield good long-lasting results with acceptable thumb IP ROM and no pain. Clinical appearance of the thumb with regard to angulation tends to be superior to radiographic findings. We prefer this method in treating Woods type I delta triphalangeal thumbs.

LEVEL OF EVIDENCE: IV.