Mallet fingers are uncommon in children. When seen in a timely fashion, immobilization usually results in acceptable outcome. Delays in diagnosis are common and may be associated with more complex digital trauma. In these circumstances, persistent extensor lags are often inevitable. A variety of surgical techniques have been advocated for the treatment of chronic mallet finger deformities. This retrospective article reports on tenodermodesis. All patients who presented with soft tissue mallet fingers were initially treated with extension splinting or casting for at least 6 weeks duration. Of those patients that failed this treatment and the extensor lag was a clinical problem, surgery was considered. This resulted in a small cohort of only 10 patients.
The surgical technique consisted of a dorsal approach with excision of the abnormal tendonous tissue, and re-approximation of the tendon. Following this, excess skin was removed to perform a dermodesis. A K-wire was placed across the DIP joint to maintain for 4-6 weeks duration. The average follow up was 6.5 years. All patients demonstrated some improvement. Two patients regain full active DIP joint extension where as 8 patients demonstrated a persistent lag of less than 20 degrees. Prior to surgery, all extension lags were equal to or greater than 40 degrees. Three patients did loose some DIP flexion following the procedure and a persistent hyperextension of the PIP joint was noted in 3 patients. Two patients also developed mild nail plate deformities. No additional surgery was performed.
This article presents a straight forward surgical procedure for soft tissue mallet finger deformity. Importantly, surgical candidates are those patients with a clinically significant extension lag of greater than 40 degrees, and those patients who have failed non-operative management. In these circumstances, this surgical technique can be considered with adjunctive Kirschner wire fixation across the DIP joint. The family and patient should be informed that improvement will occur, although some persistent extension lag may be present. In addition, some lost of flexion may occur that could compromise grasp.