Management Modalities Of Humeral Fracture Nonunion

Abstract

Background: Humeral fractures comprise 5-8% of all fractures. Nonunion is uncommon and it was reported to be less than 10-13% of all humeral fractures. But when they do occur, they present a challenge to orthopedic surgeons and often debilitate patients. Nonunion of fractured humerus often need operative treatment. Many factors have been associated with delayed union or nonunion. Both local and systemic factors are thought to contribute to the development of nonunion. Radiological investigations focus on bone and soft tissue pathology. The most commonly used investigations are; X-ray, MRI, CT and bone scan. Before embarking on any method of treatment, one should be aware of the objectives in treating nonunion. Obviously, treatment is primarily directed at healing of the fracture. However, this is not the only objective because a functionless, deformed limb with pain and stiffness of adjacent joints and a healed nonunion will not be a satisfactory end point for most patient. Emphasis must therefore be placed on returning the limb and the patient to the fullest function possible during the frequently prolonged periods of time it takes to treat nonunion. It is the surgeon’s role to identify the proper stimulus that will lead to uneventful fracture healing. In hypertrophic nonunion, the proper stimulus is stable fixation of the fracture allowing capillary ingrowth with enchondral ossification . The addition of biologic stimulus as bone graft is not necessary. However, atrophic nonunion with the restricted blood supply require the additional biologic stimulation e.g. shingling or augmentation with bone graft. Systemic as well as local fracture management must be considered in the treatment of nonunion; metabolic and nutritional factors should be optimized, patients should be encouraged to discontinue tobacco use and activity levels may require alteration. Mechanical properties of the Ilizarov device, particularly in comparisons with other external fixators have been an area of research interest. The stability provided by fixation devices is an important variable; instability can lead to ineffective bone regeneration, while an overly rigid fixation can lead to a delay of fracture consolidation. A limited degree of axial micromotion is important to promote osteogenesis and thus it is hypothesized that an optimal fixation device will provide stability while still permitting some axial micromotion. However, there are currently no data that identify what level of instability is beneficial