Changes in Tip-Apex Distance by Position and Film Distance Measured by Picture Archiving and Communication System (PACS) / 대한고관절학회지

PURPOSE: The tip-apex distance (TAD) is used to predict the clinical outcome of intertrochanteric fracture fixation. We aimed to measure the changes in TAD by position and film distance using Picture Archiving and Communication System (PACS). MATERIALS AND METHODS: We used a femur replica with a 10degrees femoral neck anteversion and a 130degrees neck shaft angle. Proximal femoral nail antirotation nail and a helical blade were inserted into the replica. Radiographs were taken at the neutral position and after applying 10degrees, 20degrees, 30degrees, 40degrees internal/external rotation, 10degrees abduction, and 10degrees and 40degrees adduction to the mechanical axis. Radiographs were taken at the replica-film distance of 10 cm and 20 cm under the same conditions, mimicking the differences in Focus-film distance (FFD), which reflect the patient's contour in clinical settings. A radiologist and an orthopedic surgeon measured the TAD twice using PACS. The average error was 2 mm (4.5%) and the standard error was +/-3.04. TADs in the neutral position constituted the standard values to measure the relative errors. RESULTS: TADs increased with an increase in the external rotation and abduction of the replica. TADs decreased with an increase in the internal rotation and adduction of the replica. For comparable measurements, relative errors were higher at FFDs of 20 cm compared to FFDs of 10 cm. CONCLUSION: Since the femur is internally rotated and adducted for reduction, orthopedic surgeons would assess the lag screw to be closer to the apex of femur on intraoperative radiographs. To have a correct measurement of the TAD after fixation of intertrochanteric fractures, radiographs should be taken in neutral position and measurement errors should be considered based on the patient's size.

Adenomyoepithelioma Located Over the Tibial Tuberosity

Adenomyoepithelioma is a rarely occurring tumor and its generation in the limbs is extremely rare. We report a case of an adenomyoepithelioma over the proximal tibial tuberosity that was treated without any complications after an excisional biopsy with a literature review.

Relation Between Adjacent Superior Segmental Disease and Facet Joint Violations After Posterolateral Lumbar Fusion

STUDY DESIGN: To analyze the relationship between the adjacent superior segment disease and facet joint violations after lumbar fusion. OBJECTIVES: We retrospectively analyzed the relationship between the adjacent superior segment disease and facet joint violations after lumbar fusion. SUMMARY OF LITERATURE REVIEW: Among numerous literatures regarding adjacent superior segment disease, there is no analysis concerning the relationship between adjacent superior segment disease and facet joint violations after lumbar fusion. MATERIALS AND METHODS: We reviewed 2056 patients who underwent lumbar fusion, between March 2004 and April 2009. Analysis was performed for 79 (3.8%) of the 2056 patients with adjacent superior segment disease and needed a second operation. A facet joint was considered as 3 types of violations with computed tomography scans if any of the following situations were encountered: pedicle screw clearly within the facet joint; pedicle screw head clearly within the facet joint; and pedicle screw and/or screw head within 1mm from or abutting the facet joint, without clear joint involvement. RESULTS: The incidence of the violations was 45% (36/79) of all patients and 28% (44/158) of all screws. The incidence of L4-5 facet joint violations was 35% (28/79) of patients with adjacent superior segment disease, statistically. CONCLUSIONS: Facet joint violations were observed in patients with the adjacent superior segment disease after posterolateral lumbar fusion. Because L3-4 facet joint violations increased when L4-5 fusion was done, more care should be taken to avoid facet joint violations when the surgeon is considered for insertion of the pedicle screws at L4-5.