RESUMO
Objective To discuss the effect of proximal interphalangeal joint(PIPJ) motion on the tension of the zone Ⅰ extensor tendon through measuring the extensor tendon and find the fixed position of PIPJ when the zone Ⅰ extensor tendon at minimum tension,and to provide reference for best fixed position in clinical treatment.Methods The maximal passive flexion angles of the distal interphalangeal joint (DIP J) of the index,distal,ring and little fingers were measured in 20 cadaver hands when the PIPJ flexed at 0 °,20 °,40 °,60 °,80 ° and 100 °.Making an incision over the back of the DIPJ to expose the zone Ⅰ extensor tendon.Incising the extensor tendon laterally at the level of the DIPJ with the DIPJ fixed in extension position to make a mallet finger.Pierced a Kirschner wire through and perpendicular to the distal phalangeal basement as a sign.Parallel to this sign,marked the zone Ⅰ extensor tendon and measured its relative distance to the sign as the sliding distance of the extensor.Recording the widest gap between the tendon edges and the tendon sliding distance while the PIPJ was in extension and 20°,40°,60°,80° and 100°flexion position,severally.Results The maximal passive flexion angle of the DIPJ increased with the PIPJ flexed from 0°to 100°in 80 fingers.The gap between the extensor tendon edges in zone Ⅰ was (1.322 8 ± 1.078 9) mm when the PIPJ was in extension position.The proximal extensor tendon glide distally while the PIPJ flexed to 100° with an average sliding distance of(1.540 5 ± 0.690 7) mm.Conclusion The zone Ⅰ extensor tendon has the maximal tension while the PIPJ is in extension position.Flexing PIPJ can make the tension decrease.
RESUMO
Objective To explore a new method for repairing bilateral acute proper digital nerve injuries. Methods From Feb. 2009 to Aug. 2012, 56 patients with bilateral acute proper digital nerve injuries were admitted to our center, with20 undergoing double end-to-side neuroanastomosis. During operation, the injured digital nerve was excised, and then the bilateral distal ends and proximal endswere stured, consequently forming the distal and proximal nerve bows. A cutaneous antebrachii lateralis nerve was freed and obtained from the homolateral forearm, and then was equally divided into 2 parts to bridge the 2 nerve bows. Twenty patients underwent nerve graft with end-to-end neuroanastomosis, and the rest 16 patients underwent direct end-to-end neuroanastomosis. Results All the patients achieved primary healing of wound after operation, with no circulation disorders. A total of 50 patientswere followed up for 3-12 months. In double end-to-side neuroanastomosis group, 18 patientswere successfully followed up, with the average sensation measurement being S3+, which was significantly higher than those of the other 2 groups(P = 0. 024). The average result of two point discrimination was (5. 2±0. 7) mm, which was significantly lower than those of the other 2 groups(P = 0. 037). According to TAM scales, the results of finger joint motion were excellent in 14 cases, good in 3 cases and fair in 1; and there were no significant differences in the motion of joints between the 3 groups (P = 0. 914). In nerve graft with end-to-end neuroanastomosis group, 19 patients were successfully followed up; the average result of sensation measurement was S2 and the average result of two point discrimination was (7. 2±1. 4) mm. In direct end-to-end neuroanastomosis group, 13 patients were successfully followed up; the average result of sensation measurement was S3 and the average result of two point discrimination was (6. 3±0. 8) mm. Conclusion The arched nerves of double end-to-side neuroanastomosis can be used for repairing bilateral acute proper digital nerve injuries, which can quickly restore the sensation of fingers, but the related conclusion needs further verification with large sample studies.