Background: osteoarthritis is the most common inflammatory joint condition and is expected to have an increasing prevalence in middle-aged and elderly patients. Objectives: to evaluate the functional outcome of open wedge High Tibial Osteotomy (HTO) versus High Fibular Osteotomy (HFO) with segment resection in management of medial compartment osteoarthritis of the knee. Patients and Methods: we compared 10 cases of HTO and 10 cases of HFO complain with uni-compartment knee osteoarthritis. Results: success in HTO depends on good technique. The determination of the exact localization of the osteotomy site, not to fracture lateral cortex, frequent assessment of the correction angle at every step of the operation, avoidance of overcorrection, the selection of an appropriate Puddu plate size fit for the osteotomy gap. During follow up, mean improvements obtained in KSS scores was 26.70. According to this assessment scale, preoperative score was deemed worse, and postoperative scores was good. HFO relieves pain and improves joint function in human knee osteoarthritis. This new surgery is simple, safe and affordable. Pain relief after surgery occurs in almost all patients. HFO may delay or replace TKA in a subpopulation of patients with knee osteoarthritis. Conclusion: HFO is a simple, safe, fast and affordable surgery to relieve pain and improve joint function and the medial joint space in human knee osteoarthritis.