Background: The treatment of complex diaphyseal malunions is challenging, requiring extensive preoperative planning and precise operative technique. We have developed a simpler method to treat some of these deformities.
Methods: Ten patients with complex diaphyseal malunions (including four femoral and six tibial malunions) underwent a clamshell osteotomy. The indications for surgery included pain at adjacent joints and deformity. After surgical exposure, the malunited segment was transected perpendicular to the normal diaphysis proximally and distally. The transected segment was again osteotomized along its long axis and was wedged open, similar to opening a clamshell. The proximal and distal segments of the diaphysis were then aligned with use of an intramedullary rod as an anatomic axis template and with use of the contralateral extremity as a length and rotation template. The patients were assessed clinically and radiographically at a mean of thirty-one months (range, six to fifty-two months) after the osteotomy.
Results: Complete angular correction was achieved in each case; the amount of correction ranged from 2° to 20° in the coronal plane, from 0° to 32° in the sagittal plane, and from 0° to 25° in the axial plane (rotation). Correction of length ranged from 0 to 5 cm, and limb length was restored to within 2 cm in all patients. All osteotomy sites were healed clinically by six months. While no deep infections occurred, superficial wound dehiscence occurred in two patients along the approach for the longitudinal portion of the osteotomy, emphasizing the importance of careful soft-tissue handling and patient selection.
Conclusions: The clamshell osteotomy provides a useful way to correct many forms of diaphyseal malunion by realigning the anatomic axis of the long bone with use of a reamed intramedullary rod as a template. This technique provides an alternative that could decrease preoperative planning time and complexity as well as decrease the need for intraoperative osteotomy precision in a correctly chosen subset of patients with diaphyseal deformities.
Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.
Disclosure: The authors did not receive any outside funding or grants in support of their research for or preparation of this work. Neither they nor a member of their immediate families received payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity. A commercial entity (Stryker Orthopaedics) paid or directed in any one year, or agreed to pay or direct, benefits in excess of $10,000 to a research fund, foundation, division, center, clinical practice, or other charitable or nonprofit organization with which one or more of the authors, or a member of his or her immediate family, is affiliated or associated.
A video supplement to this article will be available from the Video Journal of Orthopaedics. A video clip will be available at the JBJS web site, www.jbjs.org. The Video Journal of Orthopaedics can be contacted at (805) 962-3410, web site: www.vjortho.com.
Investigation performed at University of Mississippi Medical Center, Jackson, Mississippi; University of Cincinnati Medical Center, Cincinnati, Ohio; and Harborview Medical Center, Seattle, Washington
- Copyright © 2009 by The Journal of Bone and Joint Surgery, Incorporated
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