Takeshi Oshima1, Murilo Leie2, Samuel Grasso3, David A Parker3. 1. Sydney Orthopaedic Research Institute, Sydney, Australia. Electronic address: TOshima@sori.com.au. 2. Sydney Orthopaedic Research Institute, Sydney, Australia. 3. Sydney Orthopaedic Research Institute, Sydney, Australia; The University of Sydney, Sydney, Australia.
Abstract
BACKGROUND: The tibial bony attachments of the anterior cruciate ligament (ACL) and the anterolateral meniscal root (ALMR) are very close, and drilling the tibial tunnel in ACL reconstruction may damage the ALMR attachment. This study investigated the relationship between the tibial attachment of the ACL and ALMR using high-resolution 3-T magnetic resonance imaging (MRI). METHODS: Twenty healthy subjects (35.8 ± 13.0 years) had 20 knees scanned using high resolution 3-T MRI. The tibial bony attachments of ACL, ALMR, and the tibia were segmented and three-dimensional models were created. The shape, area, and location of each attachment were evaluated using this model. RESULTS: The ACL tibial attachment was elliptical in nine knees (45%), C-shaped in nine knees (45%) and triangle in two knees (10%). The mean values of the ACL vs ALMR tibial attachments were as follows: area, 106.2 ± 21.3 vs 56.2 ± 21.3 mm2; length, 16.8 ± 2.0 vs 11.0 ± 1.8 mm; and width, 6.9 ± 1.3 vs 6.6 ± 1.0 mm. The location of the ACL vs ALMR attachment centres was 46.5 ± 1.7% vs 56.5 ± 1.9% in the medial-lateral direction and 36.3 ± 3.6% vs 36.7 ± 3.5% in the anterior-posterior direction. The distance between the ACL and ALMR centres was 8.1 ± 1.3 mm. CONCLUSIONS: ACL and ALMR tibial attachments were individually distinguished using high resolution 3-T MRI. The short distance between both centres of the attachments may suggest that ALMR can be damaged when the tibial tunnel is drilled in ACL reconstruction.
BACKGROUND: The tibial bony attachments of the anterior cruciate ligament (ACL) and the anterolateral meniscal root (ALMR) are very close, and drilling the tibial tunnel in ACL reconstruction may damage the ALMR attachment. This study investigated the relationship between the tibial attachment of the ACL and ALMR using high-resolution 3-T magnetic resonance imaging (MRI). METHODS: Twenty healthy subjects (35.8 ± 13.0 years) had 20 knees scanned using high resolution 3-T MRI. The tibial bony attachments of ACL, ALMR, and the tibia were segmented and three-dimensional models were created. The shape, area, and location of each attachment were evaluated using this model. RESULTS: The ACL tibial attachment was elliptical in nine knees (45%), C-shaped in nine knees (45%) and triangle in two knees (10%). The mean values of the ACL vs ALMR tibial attachments were as follows: area, 106.2 ± 21.3 vs 56.2 ± 21.3 mm2; length, 16.8 ± 2.0 vs 11.0 ± 1.8 mm; and width, 6.9 ± 1.3 vs 6.6 ± 1.0 mm. The location of the ACL vs ALMR attachment centres was 46.5 ± 1.7% vs 56.5 ± 1.9% in the medial-lateral direction and 36.3 ± 3.6% vs 36.7 ± 3.5% in the anterior-posterior direction. The distance between the ACL and ALMR centres was 8.1 ± 1.3 mm. CONCLUSIONS: ACL and ALMR tibial attachments were individually distinguished using high resolution 3-T MRI. The short distance between both centres of the attachments may suggest that ALMR can be damaged when the tibial tunnel is drilled in ACL reconstruction.