Background: Two ligaments—the anterior cruciate & the posterior longitudinal are the primary ligaments that play a crucial role in maintaining knee stability.
The aim of the work: To compare the results of hamstring tendon graft & graft for the peroneus tendon in anterior cruciate ligament reconstruction as regarding graft tensile power, length, donor site morbidity and knee ROM in short term follow up period.
Patients and Methods: This Quasi experimental interrupted time series study was performed on Twenty cases with anterior cruciate ligament rupture classified into 2 groups: Group A [ten cases who received arthroscopic single bundle ACLR using hamstring tendon] and Group B [10 cases who received arthroscopic single bundle ACLR using peroneus Longus tendon] at the orthopedic clinics department in Al-Azhar University Hospital in Damietta from August 2022 to January 2023.  
Results: There was a statistically significant enhancement in knee range of motion, Lysholm score and International Knee Documentation Committee [IKDC] score in both groups from preoperatively to 6 months postoperatively and no statistically significant variance was found among groups regarding pre & postoperative ROM, preoperative and postoperative Lysholm score between various intervals of follow-up & preoperative & postoperative IKDC score between various intervals of follow-up. Also, a statistically significant difference was observed in thigh hypotrophy among hamstring and peroneus groups.
Conclusion: Reconstructive surgery for the ACL with peroneus Longus tendon showed no statistically significant difference regarding ankle function and preoperative & postoperative knee ROM with a benefits of a bigger graft size and less thigh hypotrophy comparable to that of hamstring tendon.