Objective      To introduce surgical methods and clinical effects of functional reconstruction of posterolateral complex (PLC) by part of peroneus longus tendon.       Methods       During July 2012 to July 2014

part of peroneus longus tendon was adopted to simulate reconstruction of 3 core ligaments of PLC to treat 24 Fanelli B or C type PLC patients with posterolateral rotation instability and rupture in substantial part of ligaments in our department. All the patients showed the combined injury

and the follow-up time was beyond 1 year. The scores of preoperative and postoperative extension of knees for 0

varus of bending of knees for 30

Dail-test

and international knee documentation committee (IKDC) were compared.       Results      All patients were followed up. No iatrogenic vascular injury occurred. All patients had no extension limit of the knee joints

but had mild bending limit. Varus circumstances included 11 cases of Ⅱ degree and 13 cases of Ⅲ degree at preoperative extension of knee for 0°

9 cases of Ⅱ degree and 15 cases of Ⅲ degree at preoperative bending of knees for 30°

2 cases of Ⅰ degree at postoperative extension of knee for 0°

and 5 cases of Ⅰ degree at postoperative bending of knees for 30°

and the rest were negative. Dial-test showed that preoperative added tibia external rotation was equally beyond 10°

including 21 cases of grade C and 3 cases of grade D. Postoperative added tibia external rotation was less than 10

including 19 cases of grade A and 5 cases of grade B. The preoperative IKDC scores of all patients were regarded as grade D

and all patients were functionally improved or significantly improved after operation

including 9 cases of grade A and 15 cases of grade B.       Conclusion      Based on anatomy and biomechanics

part of the peroneus longus tendon is used to simulate reconstruction of 3 core ligaments of PLC

which can basically reappear the shape of 3 ligaments

preferably correct excessive external rotation and external straight instability

and improve knee function to the maximum extent.