KS31: PROSPECTIVE REVIEW OF THE INCIDENCE OF THE ANTEROMEDIAL MENISCO-FEMORAL LIGAMENT (AMMFL) AND ASSOCIATED PATHOLOGY.

Abstract

The AMMFL is an anatomical variant of the attachment of the anterior horn of the medial meniscus to the posterolateral wall of the intercondylar notch. It is distinct from the meniscofemoral ligaments of Wrisberg and Humphrey. This large series prospectively documented its incidence and any associated meniscal or chondral pathology. The study period was from September 2006 until December 2007.

All patients that underwent arthroscopy of the knee for meniscal, chondral or ligamentous pathology including arthroscopic anterior cruciate ligament reconstruction were included. The procedures were performed by the two senior authors, according to their standard protocols at one of two hospitals.

All the findings from the arthroscopies were prospectively recorded in a standardized datasheet. This recorded all meniscal, chondral and miscellaneous pathology including the presence or absence of an AMMFL. This data was entered into a database including all patients.

The results of 401 arthroscopic procedures were recorded during the study period. Of these patients, 14 were found to have AMMFLs, resulting in an incidence of 3.49%, higher than previously reported. (Anderson et al describe an incidence of 0.44% from a combined retrospective and prospective review.)

The associated pathology was most commonly a radial tear of the medial meniscus, found in six patients. One had a bucket handle tear of the medial meniscus. There were three lateral meniscus tears, two of which were associated with an ACL rupture. Two patients had an ACL rupture as the only other pathology at arthroscopy. One patient was found to have a ruptured AMMFL as her only pathology.

This anatomical variant is more common in this Australian sample than has been described in the literature, and there seems to be a relationship between the presence of the AMMFL and a particular pattern of medial meniscus tear, suggesting an influence of this anatomical variant on meniscal pathology.