Evaluation of Femoral Tunnel Positioning Using 3-Dimensional Computed Tomography and Radiographs after Single Bundle Anterior Cruciate Ligament Reconstruction with Modified Transtibial Technique

BACKGROUND: The purpose of this study is to report a modified transtibial technique to approach the center of anatomical femoral footprint in anterior cruciate ligament (ACL) reconstruction and to investigate the accurate femoral tunnel position with 3-dimensional computed tomography (3D-CT) and radiography after reconstruction. METHODS: From December 2010 to October 2011, we evaluated 98 patients who underwent primary ACL reconstruction using a modified transtibial technique to approach the center of anatomical femoral footprint in single bundle ACL reconstruction with hamstring autograft. Their femoral tunnel positions were investigated with 3D-CT and radiography postoperatively. Femoral tunnel angle was measured on the postoperative anteroposterior (AP) radiograph and the center of the femoral tunnel aperture on the lateral femoral condyle was assessed with 3D-CT according to the quadrant method by two orthopedic surgeons. RESULTS: According to the quadrant method with 3D-CT, the femoral tunnel was measured at a mean of 32.94% +/- 5.16% from the proximal condylar surface (parallel to the Blumensaat line) and 41.89% +/- 5.58% from the notch roof (perpendicular to the Blumensaat line) with good interobserver (intraclass correlation coefficients [ICC], 0.766 and 0.793, respectively) and intraobserver reliability (ICC, 0.875 and 0.893, respectively). According to the radiographic measurement on the AP view, the femoral tunnel angles averaged 50.43degrees +/- 7.04degrees (ICC, 0.783 and 0.911, respectively). CONCLUSIONS: Our modified transtibial technique is anticipated to provide more anatomical placement of the femoral tunnel during ACL reconstruction than the former traditional transtibial techniques.

QUANTITATIVE ASSESSMENT OF NASAL AND UPPER LIP CHANGES AFTER LE FORT I OSTEOTOMY SURGERY USING A 3-DIMENSIONAL COMPUTED TOMOGRAPHY

Comparison of the observer reliability of cranial anatomic landmarks based on cephalometric radiograph and three-dimensional computed tomography scans

INTRODUCTION: Accurate diagnosis and treatment planning are very important for orthognathic surgery. A small error in diagnosis can cause postoperative functional and esthetic problems. Pre-existing 2-dimensional (D) chephalogram analysis has a high likelihood of error due to its intrinsic and extrinsic problems. A cephalogram can also be inaccurate due to the limited anatomic points, superimposition of the image, and the considerable time and effort required. Recently, an improvement in technology and popularization of computed tomography (CT) provides patients with 3-D computer based cephalometric analysis, which complements traditional analysis in many ways. However, the results are affected by the experience and the subject of the investigator. MATERIALS AND METHODS: The effects of the sources human error in 2-D cephalogram analysis and 3-D computerized tomography cephalometric analysis were compared using Simplant CMF program. From 2008 Jan to 2009 June, patients who had undergone CT, cephalo AP, lat were investigated. RESULTS: 1. In the 3 D and 2 D images, 10 out of 93 variables (10.4%) and 11 out 44 variables (25%), respectively, showed a significant difference. 2. Landmarks that showed a significant difference in the 2 D image were the points frequently superimposed anatomically. 3. Go Po Orb landmarks, which showed a significant difference in the 3 D images, were found to be the artificial points for analysis in the 2 D image, and in the current definition, these points cannot be used for reproducibility in the 3 D image. CONCLUSION: Generally, 3-D CT images provide more precise identification of the traditional cephalometric landmark. Greater variability of certain landmarks in the mediolateral direction is probably related to the inadequate definition of the landmarks in the third dimension.

A Size Change of Bone Defect Area after Autogenous Calvarial Bone Graft

Calvarial bone grafting in craniomaxillofacial trauma and facial reconstructive surgery is now widely recognized and accepted as a standard procedure. One of the commonly reported problems of calvarial bone graft is the contour defect caused by partial resorption of the graft. But, there are few reports that discuss the fate of the calvarial bone graft based on the quantitative data. In this article, the changes of grafted calvarial bone were evaluated using 3-dimensional computed tomography(CT). 9 patients were observed with the CT scans at 2mm thickness immediately after operation and at the time of last follow-up. The area of the bone defect was segmented on the 3-dimensional CT image and calculated by AnalyzeDirect 5.0 software. The immediate postoperative bone defect area of the recipient site and the donor site were 612.9mm2 and 441.5mm2, respectively, which became 1028.1mm2 and 268.8mm2, respectively at the last follow-up. In conclusion, the bone defect area was less increased on the donor site of calvarial bone graft than on the recipient site. And the CT scan is a valuable imaging method to assess and follow-up the clinical outcome of calvarial bone grafting.

Relationship between Femoral Anteversion and Tibial Torsion in Intoeing Gait

OBJECTIVE: The purposes of this study were to evaluate the causes of intoeing gait and to investigate the association between femoral anteversion and tibial torsion. METHODS: The subjects were 23 children with intoeing gait. The association between increased femoral anteversion and external torsion of the tibia was investigated by computed tomography and 3-dimensional computed tomography. The tibial torsion angle was measured by computed tomography. Femoral anteversion angle was measured by computed tomography and 3-dimensional computed tomography. RESULTS: The intoeing gait was caused by increased femoral anteversion in 67.4% of the cases, by internal tibial torsion in 21.7% and by other factors in 10.9%. There was a clear correlation between the degree of femoral anteversion and the degree of external torsion of the tibia. CONCLUSION: The results of this study indicate that most common cause of intoeing gait is increased femoral anteversion and that in cases of increased femoral anteversion, compensatory external torsion of the tibia develops during growth.

Comparative Analysis of Pre- & Post-operative Change in Thoracolumbar Compression Fracture, as seen on 3-dimensional Computed Tomography

Conventional radiographs and simple CT scans fail to provide accurate information about the structural integrity of a fracture site. In recent years, special 3-dimensional CT scanning has been progressively developed, and we applied this technique to thoracolumbar compression fractures. Posterolateral spinal fusion with iliac bone graft was attempted in all patients; Comparative pre- and post-operative change in these fractures was then an-alysed, using 3-dimensional CT. The results of this study suggest that this imaging is a useful non-invasive technique to assess compression fracture and determine prognosis.