This paper aims to explore the feasibility of building a finite element model of left atrial diverticulum (LAD) using reverse engineering software based on computed tomography (CT) images. The study was based on a three-dimensional cardiac CT images of a atrial fibrillation patient with LAD. The left atrium and LAD anatomical features were accurately reproduced by using Geomagic Studio 12 and Mimics 15 reverse engineering software. In addition, one left atrial model with LAD and one without LAD were created with ANSYS finite element analysis software, and the validity of the two models were verified. The results show that it is feasible to establish the LAD finite element model based on cardiac three-dimensional CT images using reverse engineering software. The results of this paper will lay a theoretical foundation for further hemodynamic analysis of LAD.
ObjectiveTo investigate the short-term effectiveness of three-dimensional (3D) printing personalized prosthesis in the treatment of giant cell tumor of bone around knee joint.MethodsA clinical data of 9 patients with giant cell tumor of bone around knee joints and met the inclusive criteria between May 2014 and August 2017 was retrospectively analysed. There were 4 males and 5 females, with an average age of 35.8 years (range, 24-50 years). The lesion located at the distal femur in 4 cases and at the proximal tibia in 5 cases. The disease duration was 5-25 months (mean, 12.9 months). According to Campanacci grading, there were 2 patients of grade Ⅰ and 7 of grade Ⅱ. The 3D printing personalized prosthesis was designed based on the CT scanning and 3D reconstruction prepared before operation. All patients were treated with the tumor resection and 3D printing personalized prosthesis reconstruction. The radiological examination was taken to observe the tumor recurrence and the Musculoskeletal Tumor Society 1993 (MSTS93) score was used to evaluate the knee function.ResultsAll operations were successful and all incisions healed by first intention without early complications. All patients were followed up 24-40 months (mean, 31.2 months). At last follow-up, no complication such as pain, pathological fracture, prosthesis loosening, or tumor recurrence occurred. The MSTS93 score was 20-29 (mean, 24.7). The knee function was rated as excellent in 6 cases and good in 3 cases, with the excellent and good rate of 100%. ConclusionFor giant cell tumor of bone around knee joint, 3D printing personalized prosthesis has the advantages of bio-fusion with host bone, mechanical stability, good joint function, and ideal short-term effectiveness. But the middle- and long-term effectiveness still need to be further observed.
Objective To investigate the effectiveness of direct lateral interbody fusion (DLIF) for lumbar degenerative diseases. Methods A retrospective study was done on 25 cases of lumbar degenerative diseases treated with DLIF between May 2013 and May 2014. There were 15 males and 10 females with an average age of 61.4 years (range, 36-78 years), including 14 cases of lumbar disc herniation, 2 cases of degenerative lumbar scoliosis, 3 cases of lumbar spondylolisthesis, and 6 cases of lumbar instability with spinal stenosis. The disease duration was 8 months to 20 years (mean, 5.7 years). The involved segments included L4, 5 in 10 cases, L3, 4 in 6 cases, L2, 3 in 2 cases, L2-4 in 2 cases, L3-5 in 3 cases, and L2-5 in 2 cases. The operation time, intraoperative bleeding volume, postoperative hospitalization time, and complications were recorded. The visual analogue scale (VAS) and Oswestry disability index (ODI) criteria were used to assess the effectiveness; X-ray film and CT were used to evaluate the bone fusion. Results The mean operation time was 105 minutes (range, 85-155 minutes), and mean intraoperative bleeding volume was 158 mL (range, 80-300 mL). The postoperative hospitalization time was 2-5 days (mean, 3.2 days). All incisions healed by first intension. There was no complication of wound infection, vascular injuries, or intraoperative visceral injuries. All cases were followed up 24.6 months on average (range, 18-30 months). Four cases had iliopsoas weakness, 5 cases had iliopsoas weakness and anterior thigh hypoesthesia, which disappeared within 6 months after operation. No retrograde ejaculation, Cage displacement, or loosening was found after operation. Full bony fusion was observed in 20 segments and partial bony fusion in 12 segments. The mean bony fusion time was 10.8 months (mean, 6-18 months). The height of intervertebral space was significantly increased to (11.98±1.20) mm at 2 days after operation and to (11.80±1.33) mm at last follow-up from preoperative (6.20±0.88) mm (P < 0.05), but no significant difference was found between at 2 days and last follow-up (P > 0.05). At last follow-up, VAS score was significantly decreased to 3.43±0.53 from preoperative 8.26±0.49 (t=26.275, P=0.000), and ODI was significantly decreased to 15.41%±3.91% from preoperative 40.80%±3.10% (t=22.902, P=0.000). Conclusion DLIF is a safe and effective treatment for lumbar degenerative diseases, which has the advantages of less tissue damage, less blood loss, and fast rehabilitation.