The aim of this review is to evaluate long-term follow-up and survival analysis studies regarding high tibial osteotomies (HTO) for the treatment of medial knee arthritis. Despite the good number of studies available, comparison and pooling of the results are challenging because of the different evaluation systems and techniques used. However, in general, published studies on HTO report good long-term results with a correct patient selection and a precise surgical technique. Based on our findings, the ideal candidate for an HTO is a young patient (<60 years of age), with isolated medial osteoarthritis, with good range of motion and without ligamentous instability. Furthermore, the literature review shows that the outcomes gradually deteriorate with time. Nevertheless, some issues remain that need resolution; these include the choice between opening or closing wedge tibial osteotomy, the graft selection in opening wedge osteotomies, the type of fixation, the comparison with unicompartmental knee arthroplasty and whether HTO significantly affects a subsequent total joint replacement.