The Thompson procedure for treating chronic mallet finger with swan neck deformity

Abstract

Objective To evaluate the outcomes of treating chronic mallet finger with swan neck deformity with Thompson procedure. Methods Eight cases of chronic mallet finger with swan neck deformity were treated with the Thompson procedure from June 2013 to October 2014. Ranges of motion of the distal interphalangeal (DIP) and proximal interphalangeal (PIP) joints were measured both pre- and postoperatively. The treatment outcomes were evaluated using Abouna and Brown criteria. Results All the patients were follow-up for 4 to 22 months with an average of 12.5 months. At the final follow-up the average extension lag of the DIP joint was ﹣6° (range, ﹣10° to ﹣5°), while that of the PIP joint was ﹣4° (range, ﹣30° to 0 °). Flexion was 61° (range, 45° to 85°) for the DIP joint and 90° (range, 80° to 110°) for the PIP joint. The swan neck deformity was corrected in all the cases. Mild Boutonniere deformity and a dimple at the proximal tied end of the tendon graft were seen in 1 case. Assessment by Abouna and Brown criteria revealed that 7 of 8 patients were recognized as cured and one as improved. Conclusion The Thompson procedure provides a predictable method for correcting loss of DIP joint extension with PIP joint hyperextension. It is an effective technique for treating chronic mallet finger with a swan neck deformity. Key words: Tendon injuries; Treatment outcome; Mallet finger; Swan neck deformity; Thompson procedure