Anatomical analysis of the traditional postero-medial approach to the ankle and evaluation of structures at risk.

Introduction: The presence of a fracture of the posterior malleolus gives a poor prognosis for ankle fractures. This study aimed to analyze the anatomical structures at risk in the traditional postero-medial (TPM) approach.

Methods: Of a total of 21 cadaveric pieces, 11 were female and 10 were male; 9 ankles/right foot and 11 ankles/left foot. The age of the specimens ranged between 66 and 98 years. The following statistical tests were performed: Median, Mean, SD and Mann Whitney non-parametric test.

Results: The p values associated with the statistical tests were calculated, obtaining all p values lower than the level of significance. Therefore, there is statistically significant evidence to reject the null hypothesis, that is, there is a difference in the medians of men and women, with respect to the 3 measurements. The evaluation of the anatomical structures at risk allowed us to measure the distance of the Posterior Tibial nerve, thus demonstrating that the approach was 20 mm above could cause injury. The difference in the measurements obtained between men and women had statistical significance.

Conclusion: Using the TPM (traditional postero-medial) approach it is possible to identify a large portion of the posterior malleolus both laterally and medially. The evaluation of the anatomical structures at risk allowed us to measure the distance of the Posterior Tibial nerve, thus demonstrating that the approach was 20 mm. above could cause injury. The difference in the measurements obtained between men and women had statistical significance. We intend to quantify visualization percentages using computed tomography in our next study.