Alternative method for direct measurement of tibial slope

The tibial slope is one of the most frequently cited anatomical causes of anterior cruciate ligament trauma. The aim of this study was to determine the possibility of direct measuring of the tibial slope of the knee without prior soft tissue dissection in cadavers.

Measurement was performed on the two groups of samples: osteological and cadaveric. The osteological group consisted of 102 matured tibiae and measurement was performed: indirectly by sagittal photographing of the tibia, and directly by a set of parallel bars. The cadaveric group consisted of 50 cadaveric knees and measurement was performed directly by a set of parallel bars. The difference and correlation between indirect and the direct measurements were observed, which included also measuring of the difference and correlation of the tibial slope on the medial and lateral condyles.

A statistically significant difference between the direct and indirect method of measuring (p < 0.01) of 1 degree was found for the tibial slope on the medial condyle, which is of no practical importance. Direct measurement of the osteological and cadaveric groups of samples did not show a statistically significant difference regarding the values of the tibial slope on the lateral condyle (p > 0.05). However, the slope on the medial condyle, as well as indirect measurement showed a statistically significant difference (p < 0.01).

By the use of a set of parallel bars it is possible to measure the tibial slope directly without removal of the soft tissue. The results of indirect, photographic measurement did not statistically differ from the results of direct measurement of the tibial slope.