Abstract:

Objective To investigate the clinical effect of extensor indicis proprius-to-extensor pollicis longus transfer in reconstructing the function of thumb drosal extension， and to provide the basis for the treatment of the disease. Methods The preoperative detailed physical examination and color Doppler ultrasound positioning were performed in the patients with spontaneous rupture of the extensor pollicis longus tendon from 2020 to 2021， and the transposition of the extensor indicis proprius was performed. The follow-up data of the patients were collected after the operation. The patients’ bilateral dorsiflexion heights of index fingers，dorsiflexion heights of thumb， thumb opposition distance，active extension angles of index finger metacarpophalangeal （MP） joint and proximal interphalangeal （PIP） joint were measured， and the Special EI-EPL Evaluation Method（SEEM） score was used to evaluate the surgical effect； through the telephone follow-up，the Brief Michigan Hand Questionnaire（BMHQ） score was scored in the form of questionnaire， and Mann-Whitney U test was used to evaluate the preoperative and postoperative overall function， daily living ability， work situation， degree of self-satisfaction， pain and total score of the patients before and after operation，so as to comprehensively evaluate the patients’ hand function， self satisfaction and the effect of extensor polliria tendon of the index finger transfer in reconstruction of function of extensor pollicis longus tendon. Results A total of 8 patients were followed up for 11－24 months， with an average follow-up of（14.8±4.2 ）months. The hands of 8 patients had good appearance without obvious scarring. There was no tendon rupture after the plaster was removed 3 weeks after operation， the tendon tension was appropriate， and the active flexion and extension of the thumb could be successfully completed. The postoperative SEEM score showed that the dorsi-extended height of the index finger on the affected side was 0.4－4.6 cm，with an average of 2.1 cm，which was lower than that on the opposite side；the loss of thumb dorsal extension elevation was 0.4－2.6 cm， with an average of 1.5 cm； the thumb opposition distance was 1.8－3.5 cm， with an average of 2.6 cm； the loss of active extension of the index finger MP joint was 0°－14°， with an average of 3°；the loss of active extension of the index finger PIP joint was 3° to 16°， with an average of 8.5°； the total score ranged from 60 to 90， with an average score of 73.8； two cases were excellent， five cases were good， and one case was normal， with an excellent and good rate of 87.5%. The BMHQ score results showed that there were significant differences in the overall hand function， daily living ability， work situation， patient’s self-satisfaction degree， pain and total score of the patients before and after operation（P<0.01）. Conclusion Extensor indicis proprius tendon has a definite effect in the treatment of spontaneous rupture of the extensor pollicis longus tendon. The thumb extension function is good after operation， and the subjective satisfaction of the patients is high. It is a reliable choice to reconstruct the function of the extensor pollicis longus tendon.

Key words: Extensor pollicis longus, Spontaneous fracture, Extensor digitorum propria, Tendon displacement, Thumb extension function