|
Journal of Bone and Joint Surgery - British Volume, Vol 90-B, Issue 3,
330-333.
doi: 10.1302/0301-620X.90B3.19898 Copyright © 2008 by British Editorial Society of Bone and Joint Surgery Variation in the anatomy of the tibial plateauA POSSIBLE FACTOR IN THE DEVELOPMENT OF ANTEROMEDIAL OSTEOARTHRITIS OF THE KNEEB. J. A. Lankester, FRCS(Tr & Orth), Consultant Orthopaedic Surgeon1; H. L. Cottam, MRCS, Specialist Registrar in Trauma and Orthopaedics2; V. Pinskerova, MD, PhD, Associate Professor3; J. D. J. Eldridge, FRCS(Tr & Orth), Consultant Orthopaedic Surgeon4; and M. A. R. Freeman, MD, FRCS, Visiting Professor3
1 Yeovil District Hospital, Higher Kingston, Yeovil BA21 4AT, UK. Correspondence should be sent to Mr B. J. A. Lankester; email: ben.lankester{at}ydh.nhs.uk
From a search of MRI reports on knees, 20 patients were identified with evidence of early anteromedial osteoarthritis without any erosion of bone and a control group of patients had an acute rupture of the anterior cruciate ligament. The angle formed between the extension and flexion facets of the tibia, which is known as the extension facet angle, was measured on a sagittal image at the middle of the medial femoral condyle. The mean extension facet angle in the control group was 14° (3° to 25°) and was unrelated to age (Spearmans rank coefficient, p = 0.30, r = 0.13). The mean extension facet angle in individuals with MRI evidence of early anteromedial osteoarthritis was 19° (13° to 26°, SD 4°). This difference was significant (Mann-Whitney U test, p < 0.001). A wide variation in the extension facet angle was found in the normal control knees and an association between an increased extension facet angle and MRI evidence of early anteromedial osteoarthritis. Although a causal link has not been demonstrated, we postulate that a steeper extension facet angle might increase the duration of loading on the extension facet during the stance phase of gait, and that this might initiate failure of the articular cartilage.
|
|


