Natural Evolution of Grafted Anterior Cruciate Ligament of the Knee: Prospective Follow-up MR Studies

PURPOSE: To described the MR findings in the periodic changes of the size and signal intensity ofreconstructed anterior cruciate ligament (ACL) of the knee and the efficacy of oblique axial imaging in patientswho underwent arthroscopic ACL reconstruction using autogenous patellar tendon. MATERIALS AND METHODS: Twenty-onepatients who had undergone ACL reconstruction were evaluated by follow-up MRI at postoperative 1 week, 1, 2, 3 and6 months, and 1 year, Conventional Fast-Spin-Echo (FSE) sagittal and coronal images and oblique axial images(proton density and T2-WI; VEMP TR/TE, 2000/20/70) were obtained perpendicular to the ligament, and using an ROIcurve in the intra-articular area, periodic changes in the cross-sectional area were evaluated by proton densityimaging and signal intensity by T2WI imaging. Cross-sectional morphology was categorized as either smooth, andround or notch-shaped and periodic changes in configuration were observed. In three cases, we evaluated the retearof reconstructed ACL by comparing the oblique axizl image obtained by conventional sagittal and coronal imaging. RESULTS: The cross-sectional area and signal intensity of grafted ACL increased significantly (p<0.05) after 3months and at 1 year, respectively. Cross-sectional morphology was smooth and round in 86% of cases, and notchedin 14%, and during follow-up MR studies, no periodic changes were seen. Notch-shaped ACL and decreased perigraftsignal intensity, as seen on sagittal images, could lead to a misdiagnosis of partial tear ; on oblique axialimages, ACL and perigraft signal intensity were found to be normal. CONCLUSION: During the natural evolution ofgrafted ACL, cross-sectional area and signal intensity increased significantly after 3 months and at 1 year,respectively ; on follow-up MR studies, cross-sectional morphology did not change, however. Oblique axial imagingprovides important information for evaluating whether the reconstructed ACL is torn or not.

A Metric Study of the Femoral, Tibial and Fibular Nutrient Foramens in Korean Adults / 체질인류학회지

For the recovery of broken bone or the free vascularized bone graft the vascular topography of the nutrient artery is very important. To estabilish the metric data of the nutrient foramen, its number, direction and site had been observed, and the size and position were measured. The results are as follows. 1. In 53% of the femurs, the number of the nutrient foramen was two, and in 57.1% of the paired materials. The number in both side was not different. The femoral nutrient foramen opened toward the superior direction in the most cases (97.3%). The foramens appeared most commonly (58.9%) on the medial lip of the linea aspera of the femur. The positional index was variable between 28.6 to 70.0 and it was 46.4±10.7 in average. Foramina appeared most commonly (41.9%) in the 30-40 index area of total length of the femur. 2. The number of the tibial nutrient foramen was one in 91.0% of the cases. All of the foramen opened toward the inferior direction. The foramen was most commonly observed on the lateral to vertical ridge of thie tibia (74.3%). Dividing the fibular into 10 parts, the positional index of the tibia was variable between 14.5 and 55.4, and it was 33.4±4.7 in an average. In 85.3% of the cases, the foramen observed in 4th segment. 3. The number of the fibular nutrient foramen was one in the most cases (81.0%). The direction of the foramen was inferior in 88.0% of the cases. The foramen positioned on the posterior surface of the fiular and its average positional index was 47.9±11.3, and its range was 20.3 to 72.4. The foramen was observed in 5th segment in the most cases (35.9%). 4. The size of the nutrient foramen was measured by the various sized stylet. The diameter of the femoral nutrient foramen was ranged from 0.5mm below 1.0mm in 46.6% of the cases. The that of the tibia was ranged from 1.0mm below 1.5mm in 53.2% of the cases. And that of the fibular was ranged from 0.5mm below 1.0mm in 54.0% of the cases.