Malunions of the proximal tibia can occur despite modern techniques of fracture fixation. These can be intra-articular, extra-articular, or a combination of both. It can result from inadequate reduction of the joint, loss of joint reduction, and/or loss of the tibial plateau fracture reduction and fixation. This can occur due to various reasons attributable to the surgery and the patient or can be implant related. The best treatment for a malunion still remains prevention, but factors out of the surgeon’s control can contribute to the development of a malunion. Oftentimes, premature weight bearing can lead to a loss of articular reduction and/or loss of fixation of the buttress component of the plateau fracture. In proximal fractures with extensive metadiaphyseal involvement requiring long plate constructs, hardware failure can occur leading to loss of fixation with development of malalignment, depending on patient compliance with follow-up, which could proceed to union resulting in a malunion or may fail to unite altogether resulting in a nonunion. Malunion of the proximal tibia alters the limb alignment and can lead to post-traumatic arthritis (PTOA). Treatment of a proximal tibia malunion is geared toward realignment of the mechanical axis of the limb so as to reduce or hopefully prevent the development of PTOA. If the patient presents with PTOA initially, correction of the deformity may alleviate some of the pain and prolong retention of the native knee prior to arthroplasty or may be needed prior to arthroplasty depending on the severity of the deformity which may prevent a successful arthroplasty. A thorough evaluation of patients presenting with deformities is required including a history of the previous injury to include surgeries and any complications which may have occurred. A frank discussion with the patient should be carried out to understand the patient’s desires and expectations. The technique of operative management for the malunion depends on the severity of the deformity itself, number of planes involved, severity of existing post-traumatic arthritis that has developed, and of course most importantly patient factors such as age, occupation, comorbidities, and existing local biology. Options can range from correction of the deformity with osteotomies and fixation to total knee arthroplasty. Correction can be done all internally or via external fixation methods.