Digital replantation in Tamai zone IV has been reported to have a relatively high survival rate; however, achieving satisfactory functional outcomes can be challenging. Herein, we report the clinical results of 19 digits from 12 patients who received postoperative hand therapy, emphasizing the extension function of the replanted digit in Tamai zone IV. The patients were 11 men and one woman, with an average age of 49.2 years (range: 28-72) . The average total active motion (TAM) at the final evaluation was 136.1° (range: 60-240°) , and the average %TAM was 52.3% (range: 23.1-92.3%) . Using the Boyes-White assessment, we classified outcomes as excellent for three patients, good for four patients, fair for four patients, and poor for eight patients. Notably, 10 of the 19 digits underwent flexor tenolysis because active flexion was inferior to passive flexion, while maintaining good active extension. Flexor tenolysis significantly improved the TAM from a median of 122.5° (range: 41-164°) to a median of 185.5° (range: 135-240°) . Our findings suggest that performing flexor tenolysis after digit replantation, while preserving extension function, leads to improved functional outcomes.
