Wed, 10/26/2011

Award for lecture about 'Single-bundle ACL reconstruction - Is the use of conventional destination devices anatomically?'

Prof. Dr. med. Wolf Petersen Head of Department for Orthopedics and Accident Surgery at Martin Luther Hospital was member of a group that was presented with an award for a lecture given by the group at the 178th Annual Meeting of the Association of Niederrheinisch-Westfälische Surgeons.

The lectures title is: 'Single-bundle ACL reconstruction - Is the use of conventional destination devices anatomically?'

HYPOTHESIS: The hypotheses of our study were that when using a conventional transtibial target device in the medial portal technique, the center of the femoral origin of the anterior cruciate ligament (ACL) will be missed but that a new media portal target device (MPA, Karl Storz) will address the anatomical center of the correctly.

METHODS USED: In 20 fresh-frozen human knees the center of the anatomic ACL origin were marked with surgical markers. Then the distance of the centers origin to the roof of the crucial ligament cave and to the deep cartilage edge was determined. In the first part of the study a conventional transtibial target device with a 5.5 mm offset in medial portal technique for addressing the femoral ACL tunnel was used. From this point the distances were determined again. The points were fitted with a radiological marker and a strictly lateral radiograph was made.

The radiographs were analyzed by the quadrant technique by Bernard and Hertel (1996). Analogous to this the medial portal targeting device was used, the distance determined and X-ray images evaluated.

RESULTS: The distances to the center of the ACL origin to the notch roof averaged 10.3 mm (± 2.1) and to the deep cartilage edge 9.5 mm (± 1.7). The center of the tunnel which was drilled with the transtibial target device had a notch roof spacing of 6.7 mm (± 1.5) and 4.8 mm (± 1.3) distance to the deep cartilage edge. After using the medial portal targeting device, the distances were 9.6 mm (± 1.9) and 8.7 mm (± 1.4).

The differences between the anatomical center and the transtibial target device were significant (p <0.05), while the differences to the medial portal targeting device were not significant (p <0.05).

The radiological evaluation yielded the following results for the anatomical origin: distance a: 28% of distance t and b: 49.5% of distance h. With the transtibial target device the following significantly different values showed up: distance a: 20.5% of distance t and distance b: 25.3% for distance h. The medial portal target device showed a distance: 26.5% of t and b: 45% of h. Compared to the anatomical origin the values were not significantly different. (p <0.05).

The assumptions of the hypotheses were confirmed by the results of the study.

A transtibial target device misses the center of the ACL when using the medial portal technique. Compared to the literature data this can be used to correctly place a tunnel for the AM bundle in a double-bundle reconstruction. With the medial portal target device an anatomic tunnel for a single-bundle reconstruction can safely be identified.