The Thompson procedure for chronic mallet finger deformity.

PURPOSE: To evaluate the outcomes of the Thompson procedure for chronic mallet finger deformity and review the utility of this procedure.

METHODS

Seven cases of chronic mallet finger with a swan neck deformity were treated by the Thompson procedure. Ranges of motion for the distal interphalangeal (DIP) and proximal interphalangeal (PIP) joints were measured, and complications were investigated at the final examination. Patients were evaluated using the criteria reported by Abouna and Brown.

RESULTS

Four patients were men, and 3 were women. The average age at the time of surgery was 44 years (range, 25 to 71 y). The middle finger was affected in 4 cases, and the index, ring, and small finger were involved in 1 case each. The average extensor lag on the DIP joint was 42° (range, 35° to 50°). All cases were treated with the Thompson procedure. The swan neck deformity was corrected in all cases. The average motion at the final examination was -4° (range, -30° to 0°) in extension and 91° (range, 85° to 110°) in flexion for the PIP joint and -5° (range, -10° to 0 °) in extension and 63° (range, 45° to 85°) in flexion for the DIP joint. A buttonhole deformity and a dimple at the proximal tied end of the graft were seen in 1 case. Assessment by the criteria of Abouna and Brown revealed that 6 of 7 patients were categorized as cured and one as improved. No patient was categorized as unchanged.

CONCLUSIONS

The procedure provides a predictable method for correcting loss of DIP joint extension with or without PIP joint hyperextension. We believe that the Thompson procedure is an effective technique for the salvage, following failed treatment, of a closed mallet injury with an associated swan neck deformity.