This retrospective cohort study was done to assess Knee functions after root tear of the posterior horn of the medial meniscus management with root tear repair or with high tibial osteotomy (HTO) with partial meniscectomy. Methods: Twenty-four patients had a posterior horn root tear, with a range of age between 38 and 56 years old. Participants in this study were classified into two groups: one received transtibial root repair, while the other underwent HTO with partial meniscectomy. Regular clinical and functional outcomes were monitored through one-year follow-up. The study aimed to compare the clinical and functional outcome for both groups. Results: There was no noteworthy difference between the two groups concerning function and pain scores. The root repair group (1) showed a higher rate of preserving joint function and slowing osteoarthritis progression in patients with isolated root tears and minimal malalignment. However, its success depends on proper healing and biomechanical factors, but Group 2 (HTO + Meniscectomy) is effective for addressing pain and overload in patients with significant varus deformity in short follow-up up but it increases cartilage wear and increases the progression of arthritis. Conclusion: Root tear of medial meniscus can be treated by repair only in acute traumatic tear with no malalignment or osteoarthritis in knee, while HTO with partial meniscectomy in degenerative chronic tears with malalignment or osteoarthritis in knees