Management of mallet finger is both difficult and controversial. Sequelae are not uncommon, particularly after surgical treatment. Many authors advocate orthopedic treatment which is less invasive but requires greater patient participation to implement. Despite the large number of orthopedic methods proposed, none has proven superiority. We report here our experience with a dorsal adhesive splint which preserves digital pulp function and improves observance.
This retrospective analysis included 270 mallet fingers presenting 153 tendon injuries and 117 bony injuries in 265 patients aged 42 years on average and treated from 2003 to 2005. Most of the tendon injuries involved the medius (38.7%) and most of the bony injuries involved the ring finger (35.4%). A splint was fashioned for the two distal phalanges and glued to the nail plate filed for this purpose. The splint was fashioned out of an L-shaped plastic sheet of thermo-malleable plastic dipped in hot water (60 degrees C). The L was molded to the dorsal aspect of the phalanges and rolled like a ring around the second phalanx, then glued to the nail. The splint was worn for eight weeks by patients with a tendon injury and six weeks for those with a bony injury. The splint was then worn at night for two weeks. Three criteria were used to analyze outcome: residual extension deficit, joint involvement, complications.
Mean follow-up was 18 months. Mean time from trauma to definitive installation of the splint was six days. The complication rate for this orthopedic method was 14.3%, complications being observed in 6% of patients. All complications were transient except for one case of swan neck deformity and one case of painful osteoarthritis. Thirty splints (11%) became unglued but were all reinstalled using the same protocol. Thirty fingers (14%) presented residual deficit of active extension measuring less than 20 degrees. The quality of the result depended on the type of injury: tendon injuries led to extension deficit in more fingers (20% versus 7.5%) but for a lesser degree (16.5 degrees versus 19.1 degrees) than bony injuries.
We observed a lower rate of complications with this technique than usually reported in the literature. Transient ungueal dystrophy only involved 2.5% of the fingers in our series. Swan neck was observed in only 8.3% of the fingers, all with tendon injuries, and resolved in all. There was only one case of symptomatic distal interphalangeal joint degeneration among the 117 fingers with bony injuries. There were no cases of skin necrosis. The results of this retrospective study, with mean 2.38 degrees extension deficit, are better than reported in other series in the literature. These results suggest that surgical indications for mallet finger should be revisited, irrespective of the type of injury, excepting when subluxation persists despite installation of the splint.
In conclusion, our series demonstrates that the adhesive dorsal splint is an effective treatment for all types of mallet finger, reducing the number of indications for surgery. Compared with other techniques, the advantages are: free digital pulp, better patient observance, lesser extension deficit.