The relationship between Parson's tubercle and the insertion of the anterior horn of the medial meniscus.

ABSTRACT

PURPOSE: The purpose of this investigation was to correlate the anatomic characteristics of the third intercondylar tubercle of Parsons (TITP) with the insertional variations of the anterior horn of the medial meniscus using precise measurements in an anatomic cadaver study. Our hypothesis was that the height of the TITP would correlate with the degree of inferior insertion of the medial meniscus. TYPE OF STUDY A cadaver study using a convenience sample. METHODS: Twenty unpaired proximal tibia specimens without advanced arthritis were analyzed with a coordinate measuring machine using a 0.479-mm diameter probe. A reference plane was created using 3 reproducible points on the tibial surface. Measurements from the TITP included another reference plane through its base, which was used to calculate its absolute height. The locations of the anterior- and inferior-most insertional points of the anterior horn of the medial meniscus were also determined. Correlations between the height of the TITP and age were also made. RESULTS: The overall height of the TITP was found to correlate with the degree of inferior insertion of the anterior horn of the medial meniscus (r =.52, P =.019). No correlation was found with the anterior placement of the meniscus (r =.12, P =.629) or with the age of the specimen (r =.14, P =.592). CONCLUSIONS: This absolute height of the TITP correlates with the inferior location of the insertion of the anterior horn of the medial meniscus. This association suggests a developmental relationship between 2 anatomic structures within the knee.