Authors: Pramod B Voleti Jason W Stephenson Paul A Lotke GwoChin Lee
Publish Date: 2013/03/28
Volume: 472, Issue: 1, Pages: 155-161
Abstract
Restoration of posterior condylar offset PCO during total knee arthroplasty is essential to maximize range of motion prevent impingement and minimize flexion instability Previously PCO was determined with lateral radiographs which could not distinguish the asymmetries between the femoral condyles MRI can independently measure both medial and lateral PCOWe identified 32 patients without a history of prior knee pathology who had both plain radiographs and MRI scans of the same knee performed The PCO was measured on lateral radiographs and compared with MRI measurements using a novel threedimensional protocolBy MRI the mean medial PCO was 29 ± 3 mm and the mean lateral PCO was 26 ± 3 mm both values were greater p 0001 and p = 003 respectively than the mean radiographic PCO of 25 ± 2 mm The medial PCO as measured by MRI was significantly greater than the lateral PCO p 0001Plain radiographs underestimate PCO as well as the asymmetry of the medial and lateral PCO compared with MRI This discrepancy is the result of both articular cartilage thickness and the anatomic differences between medial and lateral condyles Designers of knee prostheses and instrumentation should take these differences into accountEach author certifies that he or she or a member of his or her immediate family has no funding or commercial associations eg consultancies stock ownership equity interest patent/licensing arrangements etc that might pose a conflict of interest in connection with the submitted articleEach author certifies that his or her institution approved the human protocol for this investigation that all investigations were conducted in conformity with ethical principles of research and that informed consent for participation in the study was obtainedEach author certifies that he or she or a member of his or her immediate family has no funding or 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
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