Cutting Edge Orthopedics - Issue 3

Distal Tibia and Ankle Nonunions • 7  gifted surgeon requires help, and the appropriate consultants must be available from plastic and vascular surgery, internal medicine, and infectious disease. The hospital is the final element. Is the correct equipment in the house or available to be brought in? Is experienced nursing and surgical assistance available? Can the anesthesia staff care for the needs of the patient? At the end of the evaluation, the surgeon should create a complete problem list in anticipation of preoperative planning [15]. An attempt should be made to define the cause of the nonunion and reverse it. Soft tissue defects, either existing or anticipated, must be covered. The consults required should be listed and obtained. Infected nonunions require debridement, temporary stabilization, and conversion to a non-infected nonunion, with eventual staged reconstruction. Constructs with mechanical instability should be made stable; those with a gap require strategies to restore bone loss; those with deformity require a better reduction or length; and those with vascularity require a better soft tissue environment and biological stimulation. Using this problem list, a detailed preoperative plan should be drawn out in detail in all but the simplest of conditions. Putting the case on paper, often with multiple methods or implants, allows one to foresee possible obstacles to success, to define the sequential steps in the operation, to select the appropriate patient positioning as well as to ensure the availability of equipment and implants, and to make the procedure in the operating room the execution of a plan instead of a surgical adventure (Tables 1 and 2). Some nonunions need no treatment at all. Patients with normal alignment, normal function, and no pain may not require surgical treatment. This is most common with small fractures of the posterior malleolus or at the tips of the medial or lateral malleolus. Nonunions of the metaphysis are usually painful or involve deformity, while those of the articular surface predispose the patient to arthritis and require treatment. In all cases, surgery is contraindicated where the morbidity of the treatment exceeds the expected benefit in function. Table 1: Treatment suggestions: distal tibia and ankle nonunions. Classification Objective Treatment Suggestions Problems Hypertrophic nonunion Provide stability Plate, external fixation, nail with polar screws Does not require grafting Must provide adequate stability Atrophic/ oligotrophic nonunion Provide stability and biological stimulus Bone graft or appropriate substitute, stable fixation Thorough debridement or excision of nonunion Failure to provide biology and stability Nonunion with deformity Treat nonunion and deformity Deformity correction, stability and biology Formal deformity analysis Failure to restore mechanical axis Metaphyseal nonunion Maintain axial alignment Plate, external fixation, nail with polar screws Provide adequate fixation, build external fixator to foot if needed Prevention of deformity Malleolar nonunion Restore joint stability AO techniques Restore ankle mortise, stress views in OR Failure to restore joint stability Articular nonunion Restore articular surface Rigid internal fixation Arthrodesis if surface is not reconstructable Cartilage injury, poor prognosis