ABSTRACT
Purpose@#We aimed to investigate the accuracy of two-dimensional computed tomography (2D-CT)-based methods for measuring rotational alignment of the femoral component during total knee arthroplasty in comparison to reference values for three-dimensional (3D) reconstruction. @*Materials and Methods@#We selected the “most protruding transepicondylar axis section,” “most protruding posterior condylar line section,” and “distal femoral cut section” on 2D-CT images for 100 knees. We investigated posterior condylar angle (PCA) and condylar twist angle (CTA) values using three different methods on 2D-CT and compared to these values to those obtained using a 3D model. @*Results@#The mean PCA and CTA values were 2.8° and 7.0° on the 3D model and 2.0° to 2.1° and 5.9° to 6.0° on 2D-CT, respectively. Errors in PCA and CTA measurement included internal rotation of 0.8° and 1.1° with the 1-plane and 2-plane methods and 0.9° and 1.0° with the assumed resection method, respectively. @*Conclusion@#Mean errors in PCA and CTA values measured using three different methods on 2D-CT were not significantly different. However, PCA and CTA values measured on 2D-CT were approximately 1° smaller than their 3D values. Thus, we suggest that adding 1° to the mean PCA and CTA values obtained from a single plane of 2D-CT would provide values similar to those obtained from 3D reconstruction.
ABSTRACT
Purpose@#We aimed to investigate the accuracy of two-dimensional computed tomography (2D-CT)-based methods for measuring rotational alignment of the femoral component during total knee arthroplasty in comparison to reference values for three-dimensional (3D) reconstruction. @*Materials and Methods@#We selected the “most protruding transepicondylar axis section,” “most protruding posterior condylar line section,” and “distal femoral cut section” on 2D-CT images for 100 knees. We investigated posterior condylar angle (PCA) and condylar twist angle (CTA) values using three different methods on 2D-CT and compared to these values to those obtained using a 3D model. @*Results@#The mean PCA and CTA values were 2.8° and 7.0° on the 3D model and 2.0° to 2.1° and 5.9° to 6.0° on 2D-CT, respectively. Errors in PCA and CTA measurement included internal rotation of 0.8° and 1.1° with the 1-plane and 2-plane methods and 0.9° and 1.0° with the assumed resection method, respectively. @*Conclusion@#Mean errors in PCA and CTA values measured using three different methods on 2D-CT were not significantly different. However, PCA and CTA values measured on 2D-CT were approximately 1° smaller than their 3D values. Thus, we suggest that adding 1° to the mean PCA and CTA values obtained from a single plane of 2D-CT would provide values similar to those obtained from 3D reconstruction.
ABSTRACT
STUDY DESIGN: A retrospective study. OBJECTIVES: To assess the relationship between surgical outcomes and preoperative MRI findings, a retrospective review was conducted on the surgical outcomes depending on the preoperative MRI findings including type of herniation and Modic changes. SUMMARY OF LITERATURE REVIEW: In most reports, the patients that have large disc herniation were expected to have improved surgical outcomes. However, there have been controversies regarding the outcomes and Modic changes. MATERIALS AND METHODS: The retrospective review was conducted in 82 patients who underwent a discectomy for single level lumbar disc herniation. The average follow-up period was 34.2 months. Among their preoperative baseline MRI measurements, the stage of disc herniation, degree of nerve root compression, degree of dural sac compression, and Modic change of vertebral endplate were evaluated for the subsequent comparison between the preoperative and postoperative changes and ODI score. RESULTS: Patients with extrusion or sequestration type showed significant improvements compared to the patients with protrusion type disc herniation. By degree of nerve root compression, patients with root compression showed significant improvements compared to the patients who had contact type. The degree of dural sac compression revealed no correlation with changes in the ODI score. 23 of the 82 patients, the preoperative MRI showed a Modic change. Compared to the group who did not show such a Modic change, they turned out to be unrelated to the preoperative and postoperative changes in the ODI score. CONCLUSIONS: Patients who had extrusion or sequestration type disc herniation showed a better clinical improvement than protrusion type. Patients with compression type root lesion showed better clinical improvement than contact type root lesion. No correlation was noted regarding the outcomes of the surgical treatment and degree of dural sac compression or Modic changes.
