Since2007, we have used CT-based fluoroscopy-matching navigation system (Vector Vision Hip Ver.3.5.2, BrainLAB, Germany) in revision total hip arthroplasty. This system completes the registration procedure semi-automatically by matching the contours of fluoroscopic images and touching 3 adequate points to the contours of 3D bone model created in the computer. Registration procedure using fluoroscopic figures has finished before making surgical incision. It needs no elongation time during the operation. The objective of this study was to evaluate the accuracy of CT-based fluoroscopy-matching navigation system in revision THA. We analysed the acetabular cup in consecutive 33 hips with both intra-operative and post-operative alignment data (based on navigation system and CT evaluation) We further compared these measurements with results from primary THA. Data for primary THA were therefore obtained from 40 consecutive patients who underwent primary THA between August 2007 and May 2013 using the same navigation system by postero-lateral approach. We aimed the cup angle for Revision THA as following, the inclination: 40 degrees, the anteversion: 20 degrees Anteversion on the navigation system must be adjusted by the pelvic tilt.Introduction:
Material and method:
Since2007, we have used CT-based fluoroscopy-matching navigation system (Vector Vision Hip Ver.3.5.2, BrainLAB, Germany) in Total hip arthroplasty. This system completes the registration procedure semi-automatically by matching the contours of fluoroscopic images and touching 3 adequate points to the contours of 3D bone model created in the computer. Registration procedure using fluoroscopic figures has finished before making surgical incision. It needs no elongation time during the operation. The accuracy of navigation system depends on the techniques of registration used for the navigation and secure fixation of the dynamic reference markers. These could be affected by the different type of approaches. The objective of this study was to evaluate the accuracy of CT-based fluoroscopy-matching navigation system in THA and compare the cup position by anterolateral and posteolateral approaches. We analysed the acetabular cup in consecutive 132 hips with both intra-operative and post-operative alignment data (based on navigation system and CT evaluation), including 65 cases with anterolateral approach(Modified Watson Jones) (Group AL) and 67 cases with posterolateral approach(Group PL). We aimed the cup angle for THA as following, the inclination: 40 degrees, the anteversion: 20 degrees. Anteversion on the navigation system must be adjusted by the pelvic tilt.Introduction
Material and method
We conducted a prospective follow-up MRI study
of originally asymptomatic healthy subjects to clarify the development
of Modic changes in the cervical spine over a ten-year period and
to identify related factors. Previously, 497 asymptomatic healthy
volunteers with no history of cervical trauma or surgery underwent
MRI. Of these, 223 underwent a second MRI at a mean follow-up of
11.6 years (10 to 12.7). These 223 subjects comprised 133 men and 100
women with a mean age at second MRI of 50.5 years (23 to 83). Modic
changes were classified as not present and types 1 to 3. Changes
in Modic types over time and relationships between Modic changes
and progression of degeneration of the disc or clinical symptoms
were evaluated. A total of 31 subjects (13.9%) showed Modic changes at
follow-up: type 1 in nine, type 2 in 18, type 3 in two, and types In the cervical spine over a ten-year period
