Assessment of sensory outcomes after successful fingertip replantation with or without nerve repair according to amputation level.

BACKGROUND

Good sensory outcome in fingertip replantation is a major part of the success of reconstruction and using the finger. Although some sensorial outcomes have been reported in various series in the literature, there is no controlled study, which demonstrates the anatomical levels where nerve repair should or should not be performed. We aimed to assess sensorial outcomes of fingertip amputations with or without nerve coaptation according to amputation level.

METHODS

Between January 2013 and July 2018, patients with Tamai Zone 1 and Zone 2 amputations underwent replantation. The patients were divided two main groups. Patients underwent nerve coaptation were grouped as Group 1, and those coaptation not performed as Group 2. In addition, subgroups were designed according to level of the amputation. Tamai zone 1 amputations were grouped as groups 1a and 2a. Tamai zone 2 amputations were grouped as groups 1b and 2b. The mean age was 30.8 ± 30.8 years in Group 1a, 33.2 ± 12.6 years in Group 1b, 34.1 ± 13.6 years in Group 2a, 34.3 ± 11.1 years in Group 2b. Type of injury were evaluated as clean cut (with knife, saw etc.), moderately crushed, and severely crushed and/or avulsion. In Group 1a, one prominent branch of the nerve was repaired, and in Group 1b, the nerve in both side was repaired. The mean duration of replantation in Group 1a was 1 h and 40 min (1 h and 15 min-2 h), whereas this time was 1 h and 15 min (1 h - 1 h and 35 min) in Group 2a. Then, 2 h 15 min (1 h and 55 min-2 h and 50 min) in Group 1b, and 2 h (1 h and 45-2 h 25 min) in Group 2b. Mean age, type of injury and length of follow-up were statistically compared. Sensorial outcome was evaluated by 2-point discrimination test and the Semmes-Weinstein test.

RESULTS

According to the Semmes-Weinstein test, 33% of the fingers tested were normal, 58% had diminished light touch, 8% had diminished protective sensation, and 0% had loss of protective sensation in Group 1a; In Group 1b, these values were 35% (7/20), 55% (11/20), 10% (2/20), 0%; in Group 2a, 38% (6/16), 56% (9/16), 6% (1/16), 0%; in Group 2b, 25% (4/16), 44% (7/16), %25 (4/16), 6% (1/16), respectively Mean static two-point discriminations in Groups 1a, 1b, 2a, and 2b were 4.17 ± 0.58, 4.55 ± 0.69, 4.25 ± 0.68, and 5.9 ± 1.26 mm, respectively. The mean follow-up duration was 24 months in Group 1a, 24 months in Group 1b, 26 months in Group 2a, 21 months in Group 2b. Then, 17 (3 in Group 1a, 6 in Group 1b, 4 in Group 2a, 4 in Group 2b) of the 64 fingers were clean cut amputation, 45 (9 in Group 1a, 14 in Group 1b, 11 in Group 2a, 11 in Group 2b) were moderately crushed amputation, and 2 (1 in Group 2a, 1 in Group 2b) were severely crushed and/or avulsion injury. There was no statistically significant difference between groups 1a and 2a (p = .71). On the other hand, there was a statistically significant increase in sensory outcomes of patients in Group 1b compared to Group 2b (p = .009). There was no statistically significant between the groups in terms of mean age, type of injury and length of follow-up.

CONCLUSION

We think that nerve repair does not have a positive effect on sensorial recovery in Tamai Zone 1 amputations, but nerve coaptation should be performed in Tamai Zone 2 replantations if possible for better sensorial result.