Affiliations: [a] M.E. Mueller Research Center for Orthopaedic Surgery, University of Bern, Bern, Switzerland | [b] BG Trauma Center Ludwigshafen, University of Heidelberg, Ludwigshafen, Germany | [c] Department of Orthopaedics, Kantonsspital Luzern, Luzern, Switzerland
Correspondence:
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Address for correspondence: Dr. Guoyan Zheng, M.E. Mueller Research Center for Orthopaedic Surgery, Institute for Surgical Technology and Biomechanics, University of Bern, Stauffacherstrasse 78, CH-3014 Bern, Switzerland. Tel.: +41 31 631 5956; Fax: +41 31 631 5960; E-mail: Guoyan.Zheng@MEMcenter.unibe.ch.
Abstract: High tibial osteotomy is a widely accepted treatment for unicompartmental osteoarthritis of the knee and other lower extremity deformities, particularly in young and active patients. However, it is generally recognized as a technically demanding procedure. The lack of intraoperative control of the mechanical axis of the affected limb often results in postoperative malalignments, which is one of the main reasons for poor long-term results. Moreover, inaccurate osteotomies, such as insufficient or excessive bone cut, or incorrect orientation of the chisel or saw blade, have been observed. A computer assisted intraoperative planning and navigation system is therefore proposed in order to address these technical problems. During operation, fluoroscopic images are acquired and anatomical landmarks are digitized; a patient-specific coordinate system is established accordingly. After the three-dimensional measurement of the deformity and interactive planning of the osteotomy plane, the deformity is corrected under navigational guidance. The proposed system has been successfully introduced into the clinical practice of surgery after encouraging laboratory evaluations, with results affirming that it is safe and accurate.
Keywords: Computer assisted surgery, high tibial osteotomy, fluoroscopy, navigational guidance
