Correlation between posterior offset of femoral condyles and sagittal slope of the tibial plateau

Abstract

The aim of this study was to address, in normal knees, the variability of posterior offset of femoral condyles and tibial slope, and the presence of any correlation between the two that might be needed to achieve an adequate joint motion in flexion. Magnetic resonance images of normal knees of 80 subjects, 45 males and 35 females, with a mean age of 38.9 years, were analysed. Measurements were performed by two independent observers using an imaging visualization software. The tibial slope averaged 8 and 7.7°, on the medial and lateral sides, respectively (P = 0.2); the mean posterior offset of femoral condyles was 27.4 and 25.2 mm on the two sides, respectively (P = 0.0001). The variation coefficient of the condylar offset and tibial slope was 11.5 and 38%, respectively. In the medial compartment, a significant correlation was found between the femoral condylar offset and the tibial slope, while the same was not observed in the lateral compartment of the knee. Magnetic resonance imaging allows the assessment of tibial slope and femoral condylar offset in the medial and lateral side separately, taking into account any difference between the two compartments. The sagittal tibial slope exhibits a greater variability compared with the posterior offset of femoral condyles. The correlation found, in the medial compartment, between the tibial slope and femoral condylar offset suggests that the reconstitution of the proper morphology of the posterior part of the knee joint may be necessary to obtain a full range of motion in flexion after total knee replacement.

Important Differences Exist in Posterior Condylar Offsets in an Osteological Collection of 1,058 Femurs

“…We suspect this is due to the variable nature of the intercondylar fossa. We identified that the medial and lateral PCOs are not symmetrical, corroborating early work suggesting medial PCO is greater than lateral PCO [6,22,23]. While the significance of this is unclear, some authors have suggested that existing arthroplasty systems do not adequately account for a non-uniform PCO [2].…”

“…2) In the second technique, measurements were taken along the anatomic transepicondylar axis (TEA) and measured from the deepest point of the intercondylar fossa along the TEA, as has been similarly reported in studies utilizing MRI [6,15]. For both measuring techniques, a virtual TEA was created by determining the most medial and lateral aspects of the femoral condyles.…”

“…However, if PCO is not restored, impingement of the posterior aspect of the tibial insert against the posterior femur can limit flexion, cause pain, and affect long term function. Some authors have suggested medial PCO is greater than lateral PCO, however normative indices have not yet been established [6]. Related studies on femoral anatomical characteristics influenced by gender, race, and age have been reported with highly variable results.…”

The Tibial Slope in Patients With Achondroplasia: Its Characterization and Possible Role in Genu Recurvatum Development

“…The mean tibial slope for all achondroplasts evaluated was +1.32 ± 7 degrees, which was significantly more anterior than the slopes reported in the literature for adults (7.2 to 10.7 degrees, P = 0.0001) 8,9 and children (10 to 11 degrees, P = 0.0001). The mean tibial slope for all achondroplasts evaluated was +1.32 ± 7 degrees, which was significantly more anterior than the slopes reported in the literature for adults (7.2 to 10.7 degrees, P = 0.0001) 8,9 and children (10 to 11 degrees, P = 0.0001).…”

Characteristics of femorotibial joint geometry in the trochlear dysplastic femur

“…In the literature, PCO measurements vary greatly in size, with some studies reporting a larger medial than lateral PCO in healthy people (Cinotti et al. ; Wang et al. ).…”