ABSTRACT
Objective:To investigate the safety and feasibility of modified pararectus abdominis approach in the anterior plate fixation of sacral fractures.Methods:In 5 fresh adult cadavers (3 males and 2 females), gross anatomy was performed on one pelvic side using a modified pararectus abdominis approach to clarify the anatomical structures around the approach. On the other side of the pelvis, the anterior structures of the sacrum were exposed in simulated anterior plate fixation of sacral fracture via the modified pararectus abdominis approach. The exposed anatomic range of the approach, and the locations and courses of lumbosacral trunk nerve and iliac vessels were observed and recorded.Results:(1) The modified pararectus abdominis approach exposed the whole S1 vertebral body from the sacroiliac joint to the medial side, the L5 vertebral body cephalally, the S1 foramina in the true pelvis, and the same structures laterally as a traditional pararectus abdominis approach did. (2) Via the modified pararectus abdominis approach, exploration and decompression of the lumbosacral plexus (from L4 to S1) (including S1 foraminoplasty) were performed under direct vision to decompress the nerve entrapment from anterior compressed fracture fragments and hyperplastic callus. (3) There was a safe surgical area in anterior L5 and S1 where a plate could be safely fixed to the S1 vertebral body. (4) Since the maximum vertical distance from the lumbosacral trunk nerve lifted above the periost to the sacral ala was 1.4 cm (range, from 1.2 to 1.5 cm), a plate could be safely placed from the subperiosteum to the S1 vertebral body to fix the fracture.Conclusions:The modified pararectus abdominis approach is safe and feasible for exploration and decompression of lumbosacral nerves in the anterior sacral region (from L4 to S1) because it has significant advantages in vision and operation. It also broadens the range of anterior sacral plate fixation because a sacral fracture displacement can be reduced under direct vision and a plate can be fixated to the S1 vertebral body along the alae sacralis and across the sacroiliac joint to the iliac bone.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the application of 3D printing and digital technology in preoperative assessment and planning of internal fixation surgery for complex tibial plateau fracture.</p><p><b>METHODS</b>Complex tibial plateau fractures and commonly used plates for tibial plateau were imaged using computed tomography (CT) to reconstruct the 3D fracture and plate models. The 3D models were used to perform virtual reduction and preoperative planning of internal fixation surgery with the most appropriate plates assisted by the 3D library of plates. According to the optimal plan, the 3D physical models of tibial plateau fractures and plates were 3D printed to simulate internal fixation operation. The effects of internal fixation were compared between the virtual surgery and the simulated surgery based on the 3D models.</p><p><b>RESULTS</b>The effects of internal fixation in the simulated surgery based on the 3D models were consistent with those of the virtual surgery. No significant difference was found in the screw length between the two surgeries.</p><p><b>CONCLUSION</b>The combination of 3D printing and digital design can improve the effects of internal fixation for complex tibial plateau fractures.</p>
Subject(s)
Humans , Bone Plates , Bone Screws , Fracture Fixation, Internal , Fractures, Bone , Printing, Three-Dimensional , Tibial Fractures , General Surgery , Tomography, X-Ray ComputedABSTRACT
<p><b>OBJECTIVE</b>To investigate the relationship between the mean CT value and bone density value and explore a rapid and accurate image segmentation method for lumbar CT values in different age groups.</p><p><b>METHODS</b>We randomly collected thin lumbar spine CT scan data from 202 patients stratified by gender and age (at the interval of 10 years). The data of each group were imported into Mimics 14.0 software to obtain independent Mask files using the new image segmentation method. The Mask files were used to fill the empty space and calculate mean, maximum, and minimum CT values.</p><p><b>RESULTS</b>In the age groups of 21-30, 31-40, 41-50, 51-60, and 61-70 years, the male subjects had mean CT values of 424.94 ± 52.23 Hu, 405.59 ± 53.60 Hu, 361.76 ± 53.50 Hu, 344.17 ± 47.76 Hu, and 332.88 ± 58.33 Hu, respectively; the values in the female group were 439.89 ± 50.99 Hu, 448.06 ± 65.89 Hu, 421.43 ± 54.74 Hu, 369.07 ± 78.27 Hu, and 304.98 ± 55.05 Hu, respectively. The mean CT value in men aged 61-70 years was significantly lower than the values in men below 50 years (P<0.05), but comparable with that in those aged 51-60 years (P>0.05); The mean CT value was significantly lower in women aged 51-70 years groups than in those aged below 50 years (P<0.05).</p><p><b>CONCLUSIONS</b>The mean CT values are correlated with the bone density values. The new image segmentation method allows rapid and accurate acquisition of the CT values in the regions of interest. The lumbar mean CT values tend to decrease with age.</p>