Thumbs Up! A Novel Use of the Acutrak Screw Fixation System for the Management of Triphalangeal Thumb

CASE REPORT

A right-handed, dominant 16-year-old girl presented to outpatients with a congenital deformity of both thumbs. She was otherwise fit and well. She had three sisters, all of whom were unaffected, and there was no family history of such abnormalities affecting the hand, limbs, cardiovascular, or gastrointestinal system. On examination, she had bilateral triphalangism, clinodactyly with ulnarward deviation in each thumb (Figs 2 and 3). Functionally, she complained of stiff distal interphalangeal joints (DIPJ) with a maximum of 10 degrees of passive flexion and extension, but had good active and passive flexion and extension at the proximal interphalangeal joints. The patient and the parental consent from the patient as well as the parents was sought and granted in the production of this article.

Figure 1. This illustration shows the shaded rudimentary bone developing as an asymmetric secondary ossification center that is larger than normal. Triphalangeal thumb. From Gupta et al.9.

Figure 2. Preoperative photographs of both hands depicting the bilateral triphalangism and clinodactyly of the thumbs.

Figure 3. Preoperative radiograph of both hands showing the delta phalanx of the triphalangeal thumbs.

As the patient desired improved function and better cosmesis, she and her parents were keen on surgical correction. She subsequently underwent fusion of the DIPJ of the left thumb only initially, with Acutrak screw fixation system. A 14.0-mm titanium fusion screw device was used to fuse the joint across the articular surfaces of the joints fashioned postosteotomy. The DIPJ articular surface was excised via osteotomy, and the proximal end of the anomalous phalanx was then fused to the distal end of the distal phalanx to create a single phalanx (Figs 4 and 5). She made an uncomplicated recovery. Six weeks postcorrection, she had 60 degrees flexion at her left thumb interphalangeal joint and was delighted with the result, both with respect to her functional use and the appearance of her “normal” thumb. She opted for the correction of the contralateral deformity and is keen to pursue fashion at college.

Figure 4. Postoperative photographs at 12 weeks.

Figure 5. Postoperative radiographs at 12 weeks.

DISCUSSION

According to the Buck-Gramcko system, the treatment of type II triphalangism comprises excision of the short triangular bone, the delta fragment (Fig. 2) with a closing wedge osteotomy.⁵ Although this is largely the accepted method of management of type II anomalies, we feel the use of Acutrak screw fixation provides better results, in terms of surgical approach, namely quicker operation times, shorter pediatric anesthesia, better intraoperative visualization, and perhaps most importantly, a one-stage procedure. The senior author (C.N.McG.) feels that the Acutrak screw maintains better compression through cyclic loading compared to Herbert or AO screws, (AO Foundation, Switzerland), and as a result, higher rates of union are achieved. Further, due to the technical ease of the insertion procedure, as well as the Acutrak screw fixation system, the procedure can be performed quickly and safely giving good results. Similarly, with respect to postoperative outcome, better joint fusion and alignment, subsequent stability, function, and cosmesis, together with patient satisfaction, are achievable with this technique, which makes it arguably superior to existing methods of management.