Assessment of C1 lateral mass screw trajectory and position by plain radiographs / 局解手术学杂志

Objective The aim of this study was to provide methods for predicting ideal trajectory and position of C1 lateral mass screw (C1 LMS)from plain radiographs.Methods A total of 40 consecutive subjects (with 79 screws)who had undergone C1 LMS placement were enrolled.To evaluate the C1 LMS position,the positions of screw head and tips on anteroposterior radiographs,screw length,and height on lateral radiograph were graded as 0°,Ⅰ°,and Ⅱ°,respectively.On the postoperative computed tomography images,the lateral mass (LM) perforation,screw-thread engagement percent(%),bicortical fixation,extruded screw length,and violation of adjacent joints were analyzed. Results Screws with tip located medial to LM(tip 0)showed LMperforation in all cases.Polyaxial head located within the LM(head 0)or crossing the lateral margin of the LM(head Ⅰ)showed no LMperforation.Screw-thread engagement percent was the highest with head Ⅰ-tip Ⅰ (medial half of LM)position (97.6%),followed by head 0-tip Ⅰ (90.5%)and head Ⅰ-tip Ⅱ (lateral half of LM)(86.4%). Screws longer than the posterior half of C1 anterior arch (AA)showed bicortical fixation in all cases with mean extruded screw length of 1.9 mm.Adjacent joint was not violated in 98%,with the screw height below half of C1 AA.Conclusion On an anteroposterior radiograph, a C1 LMS with the screw head located on the lateral margin of the LMand with the screw tip in the medial half of the LMresulted in the safest and longest trajectory.On lateral radiograph,a screw tip that is placed within the anterior-inferior quadrant of the C1 AA results in safe bicorti-cal fixation without injury to the adjacent structures.These plain radiographic findings may be helpful bothpostoperatively and intraoperatively for assessing the trajectory and length of the screw.

Postoperative pneumoperitoneum: guilty or not guilty? / 대한외과학회지

PURPOSE: The aim of this study was to determine the incidence and duration of postoperative pneumoperitoneum on plain radiographs and to identify the radiologic findings associated with anastomotic leakage. METHODS: A retrospective analysis was conducted on plain radiographs of 384 patients who underwent intra-abdominal anastomoses between March 2005 and December 2008. RESULTS: Of the 384 patients, 93 patients (24.2%) had postoperative pneumoperitoneums. Of the 93 patients, 86 patients (92.5%) had physiologic pneumoperitoneums and 7 patients (7.5%) had pneumoperitoneums associated with anastomotic leakage. The initial air height was significantly greater in the leakage group than the physiologic air group (12.16 +/- 7.65 mm vs. 7.71 +/- 5.08 mm, P = 0.04). The area under the receiver operating characteristic curve of the initial height of free air for anastomotic leakage was 0.69 (95% confidence interval, 0.59 to 0.78). The best cut-off point was 11.7 mm. The height of the pneumoperitoneum increased with time in the leakage group. Ileus was significantly more prevalent in the leakage group than the physiologic air group (P 11.7 mm, increasing air height over time, and the presence of ileus on plain radiographs suggest a high likelihood of anastomotic leakage.

Prediction of Amount of Mandibular Set Back with 3 Plain Radiographs in Mandibular Sagittal Split Ramus Osteotomy

Diagnosis of Burst Fracture of the Spine on Plain Radiographs Using the Wintopo(R) Program / 대한정형외과학회잡지

PURPOSE: To evaluate the usefulness of plain lateral radiographs processed by the Wintopo(R) program (SoftSoft.netTM, version 1.11, USA)for a picture archiving communication system (PACS) for the diagnosis of bursting fracture. MATERIALS AND METHODS: From January 2001 to April 2002, 24 cases of thoracic and lumbar spine fractures with available computed tomographs were evaluated. Lateral plain radiographs were reviewed by five orthopedic residents, and then were saved as bmp files in a picture archiving communication system. The borderline posterior body in the lateral plain radiographs was defined using the vector image in the Wintopo(R) program. After processing, radiographs were re-evaluated. RESULTS: In all participants, the sensitivity of the diagnosis of bursting fracture was significantly improved after Wintopo(R) program processing. Although the specificity and positive predictive value were improved by processing, this was not statistically significant. CONCLUSION: Wintopo(R) program processing of plain lateral radiographs of the spine could improve the sensitivity of diagnosis for bursting fracture in acute spinal injury.

Comparision of Imaging Features with Surgical Findings in the Patients with Craniosynostosis

OBJECTIVE: The purposes of this study are to compare imaging features with operative findings and to determine significance of imaging studies for early detection of craniosynostosis(CS). METHODS: Plain radiograph of skull and three-dimensional(3D) CT reconstruction were analyzed in 10 consecutive patients with CS to assess the presence and the extent of synostosis. The radiological findings were investigated and compared with operative findings. RESULTS: The locations of lesion were coronal suture in 6, sagittal suture in 3 and multiple sutures in one patient, and the age ranged 1 to 53 months(mean age: 17.4 months). Reconstructive procedures with or without advancement of supraorbital rim were performed in coronal CS patients and PI-procedures or synostectomy were done in sagittal CS patients. Radi-ological abnormalities such as sutural indistinctness or sclerosis, bony ridge, bossing and other bony deformities were nearly consistent with surgical findings. CONCLUSION: The interpretation of imaging study are very important for early detection of craniosynostosis, especially, the plain radiographs of skull. Also 3D CT imaging is helpful in diagnosis and surgical planing of craniosynostosis. There are no significant differences between imaging features and operative findings in CS patients.