Osteotomy for Lower Extremity Malalignment

When performing an osteotomy for lower extremity malalignment, several complications can occur. These can include introducing iatrogenic malalignment, intraoperative fracture or vascular injury, postoperative recurrence of deformity, patella baja, and challenges when performing subsequent total knee replacement in the future. Likewise, a poor functional result can occur secondary to poor preoperative planning and patient selection. In this article, we review the complications that can occur as a result of errors made before, during, and after surgery. This article pertains to opening and closing wedge osteotomies of the distal femur and proximal tibia. Avoidance of Major Complications Although several technical, intraoperative errors can occur, appropriate patient selection is paramount to avoid poor functional outcomes (Table 1). For example, it is not advisable to perform a high tibial osteotomy to unload the medial compartment in the setting of significant, lateral and/or patellofemoral arthritis, medial tibial bone loss greater than 2 or 3 mm, ROM less than 90 , flexion contracture greater than 15 , ligamentous instability resulting in worsened instability after bone cuts, and/or inflammatory arthritis. Intraoperatively, placing a sandbag under the hip of the affected limb allows better access to the lateral aspect of the limb. It is also important to maintain the knee at 90 as the neurovascular bundle is less vulnerable to injury in this position. With regard to technical aspects of the procedure, the cutting jig must be meticulously placed to avoid introducing an anterior or posterior slope to the cut. Carrying the apex of the osteotomy cut to within 10 mm of the far cortex and leaving the proximal fragment at least 15 mm thick can help avoid fracture. Patella baja can be prevented after a lateral closing wedge high tibial osteotomy by using rigid internal fixation and aggressive postoperative mobilization, rather than prolonged casting. Detection and Treatment of Major Complications Avoiding preoperative patient selection issues can be addressed with a thorough history and physical examination, radiographic evaluation with full-length standing films, and arthroscopic evaluation, preoperatively and at the time of the planned osteotomy. Intraoperatively, one must monitor for vascular injury by detailed observation of the surgical site (letting down the tourniquet if necessary) as monitoring perfusion of the limb is difficult with the leg obscured by drapes. Similarly, it is advisable to perform these procedures where a vascular surgeon is available in case an injury occurs. Some injuries may be detected postoperatively on neurovascular check (ie, pseudoaneurysm) and some may be managed conservatively, but a vascular surgeon should be notified. Judicious use of fluoroscopy must be used to assess for iatrogenic malalignment or fracture. Each author certifies that he or she, or a member of their immediate family, has no commercial associations (eg, consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article. All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research editors and board members are on file with the publication and can be viewed on request. L. Koyonos (&), N. Slenker, S. Cohen Rothman Institute, Thomas Jefferson University, 925 Chestnut Street, Philadelphia, PA 19107, USA e-mail: loukaskoyonos@gmail.com 123 Clin Orthop Relat Res (2012) 470:3630–3636 DOI 10.1007/s11999-012-2392-6 Clinical Orthopaedics and Related Research® A Publication of The Association of Bone and Joint Surgeons®