Radiological Results and Assessment of Navigation-Guided Total Knee Arthroplasty

PURPOSE: To assess the accuracy of implantation by radiologic results of navigation-guided total knee arthroplasty and compare radiologic results with navigation data. MATERIALS AND METHODS: Between September 2004 and May 2007, total knee arthroplasties were performed in 105 knees using navigation system and radiological results(group A) were compared with navigation data(group B). All patients had standing long anteroposterior radiographs of the lower extremities and supine lateral views of the knees at 6 weeks postoperatively. Mechanical axis deviation, alpha, theta, beta, gamma and delta angles were measured. Excepting alpha and gamma angles since there were no corresponding results among navigation data, reliability analysis was done for 4 angles. RESULTS: Radiological alignment on coronal plane relating to long-term prognosis were satisfactory in 97%. In analysis for reliability, mechanical axis deviation, theta, beta and delta angles showed moderate agreement. CONCLUSION: Radiological results of navigation-guided total knee arthroplasty allowed proper alignment and showed moderate agreement with navigation data, and thus navigation system will help to predict the postoperative radiological results.

Posterior Correction of Idiopathic Scoliosis With using Transpedicular Screw Fixation / 대한척추외과학회지

STUDY DESIGN: This is a retrospective study. OBJECTIVES: We wanted to determine the effectiveness of performing transpedicular screw fixation in idiopathic scoliosis surgery by evaluating the radiological results. LITERATURE REVIEW SUMMARY: Deformity correction using pedicle screw fixation in scoliosis surgery is one of the most effective methods of treatment. However, the extent of correction and the complication rate are quite variable. MATERIALS AND METHODS: We evaluated the radiological results of performing posterior correction with using transpedicular screws in sixty patients who were suffering with idiopathic scoliosis. The follow-up duration was 39 months (range: 12 to 91 months). The changes of the coronal and sagittal geometry in the major and compensatory curves were measured according to the Cobb method with using the anteroposterior and lateral radiographs in the standing and lateral bending positions before the surgery and at the final follow-up. RESULTS: In the coronal plane, the average correction rate of the major curve was 77% and that of the compensatory curve was 72% on the immediate postoperative radiographs. In the sagittal plane, the Cobb angle in those patients who had a hypokyphosis under 15 degrees was improved from 9.0 degrees to 21.2 degrees. The angle between the lowest instrumented vertebra and T10, and also the lumbar lordosis did not change significantly. The correction rate of the rotational deformity of the apical vertebra was 55%, and that of the translation degree was 68%. The correction rate of the translation of the lowest instrumented vertebra was 54% and that of the tilting angle was 77%. No patients had a significant loss of correction in the coronal or sagittal plane at the latest follow-up. CONCLUSIONS: Posterior correction using transpedicular screws was an effective method for treating idiopathic scoliosis, and it resulted in a high correction rate at the major curve and the compensatory curve even with short segment fixation, and it reduced the loss of the correction angle.