Swan-neck deformity (SND) of the fingers can cause major functional impairment. The Zancolli–Tonkin procedure is a crossed dynamic tenodesis that prevents overextension of the proximal interphalangeal (PIP) joint and promotes extension of the distal interphalangeal (DIP) joint. We assessed the outcomes of this procedure in patients with SND due to various causes.

The Zancolli–Tonkin procedure provides effective and stable correction of SND due not only to RA, but also to other conditions.

Consecutive patients managed at two centres between 2000 and 2013 were included. The causes of SND were inflammatory joint disease, trauma, iatrogenic events, and neurological disorders. The same operative technique was used in all patients.

Forty-one fingers in 14 patients were evaluated. After a mean follow-up of 8 years, all patients could harmoniously flex the operated fingers and none had recurrence of the deformity. At the PIP joints, mean active flexion was 86° (range: 40°–90°) and mean loss of extension was 15° (range: 0°–40°). At the DIP joints, mean active flexion was 65° (range: 0°–70°) and mean extension lag was 4° (range: 0°–30°). The mean visual analogue scale pain score was 1/10 (range: 0/10–8/10) and the mean patient satisfaction score was 7.5/10 (range: 4/10–10/10).

The SND was corrected and the results were stable after 8 years in all cases. Advantages of the Zancolli–Tonkin procedure include limited invasiveness, with no need to harvest a distant tendon, and rapid active postoperative rehabilitation. The moderate excessive PIP joint flexion has no adverse impact on the overall functional outcome. The high level of patient satisfaction reflects the improvements in function.

The Zancolli–Tonkin procedure is a simple and reliable technique that provides lasting correction of an incapacitating deformity associated with impaired overall hand function.

IV.