One-stage posterior en-bloc spondylectomy following reconstruction with individualized 3D printed artificial vertebrae for multi-segment thoracolumbar metastases: case report and literature review.

In thoracolumbar vertebral tumors, reconstruction of complex multi-segment thoracolumbar vertebrae after total en-bloc spondylectomy (TES) is still challenging. In recent years, with the development of 3D printing technology, individualized 3D printed artificial vertebrae have been attempted to reconstruct complex multi-segment thoracolumbar spine. Compared with traditional titanium mesh or bone transplantation, it helps reduce long-term complications, bringing a new dawn for reconstructing multi-segment thoracolumbar spine. A 69-year-old female complained of low back pain with limited motion for 1 month. More than 2 months ago, she underwent radical mastectomy due to breast cancer (Luminal A subtype). Imageology examination revealed an osteolytic lesion involving the T11-L1 vertebra. She was performed one-stage 3-segment (T11-L1) en-bloc spondylectomy via posterior approach, and then an artificial vertebrae produced by a novel individualized 3D printing technology was used for reconstruction. The patient was follow-up for 2 years, and she recovered well, with no tumor recurrence, and no complications after spinal reconstruction. The application of individualized 3D printed artificial vertebrae in multi-segment thoracolumbar spine reconstruction can not only reconstruct the bone defect more accurately through the individualized design, but the porous design is able to achieve biomechanical performance comparable to that of cancellous bone, and it is conducive to inducing bone growth, all of which help reduce long-term mechanical complications. Furthermore, the application of artificial vertebrae in surgery can significantly shorten the operation time, reduce intraoperative blood loss and reduce the risk of perioperative complications. Therefore, individualized 3D printed artificial vertebrae is a good choice for complex multi-segment thoracolumbar spine reconstruction.

Evaluation of porous gradient hydroxyapatite/zirconia composites for repair of lumbar vertebra defect in dogs.

OBJECTIVE: To evaluate the effects of porous gradient composites with hydroxyapatite/zirconia and autologous iliac in repair of lumbar vertebra body defects in dogs. METHODS: (1) New porous gradient hydroxyapatite/zirconia composites were prepared using foam immersion, gradient compound and high temperature sintering; (2) A total of 18 adult beagle dogs, aged five to eight months and weighted 10-13 kg, were randomly assigned into two subgroups, which were implanted with new porous gradient hydroxyapatite/zirconia composites (subgroup A in 12) or autologous iliac bone (subgroup B in 6); (3) The post-operative data were analyzed and compared between the subgroups to repair the vertebral body defect by roentgenoscopy, morphology and biomechanics. RESULTS: The porosity of new porous gradient hydroxyapatite/zirconia composites is at 25 poles per inch, and the size of pores is at between 150 and 300 µm. The post-operative roentgenoscopy displayed that new-bone formation is increased gradually, and the interface between composites and host-bone becomes became blur, and the new-bone around the composites were integrated into host-bone at 24 weeks postoperatively in subgroup A. As to subgroup B, the resorption and restructure were found at six weeks after the surgery, and the graft-bone and host-bone have been integrated completely without obvious boundary at 24 weeks postoperatively. Histomorphologic study showed that the amount of bone within pores of the porous gradient hydroxyapatite/zirconia composites increased continuously with a prolonged implantation time, and that partial composites were degradated and replaced by new-bone trabeculae. There was no significant difference between subgroups (P > 0.05) in the ultimate compressive strengths. CONCLUSION: New porous gradient hydroxyapatite/zirconia composites can promote the repair of bony defect, and induce bone tissue to ingrow into the pores, which may be applied widely to the treatment of bony defect in the future.

Effectiveness comparison of cervical vertebral restitution after anterior corpectomy by two different kinds of artificial vertebrae / 中国医师进修杂志

Objective To compare the clinical outcomes of cervical vertebral reconstruction using titanium mesh and nano-hydroxyapatite and polyamide 66 (n-HA/PA66) mesh as two different kinds of artificial vertebrae. Methods From January 2008 to June 2009 had surgically treated 37 cases of cervical spondylosis with anterior corpectomy for decompression, and artificial vertebrae implanted combined platescrews fixation for cervical reconstruction and fusion. As a vertebral substitution, titanium mesh were implanted in 25 cases ( group A ), and the others (12 cases, group B) were implanted with n-HA/PA66 mesh. The height of fusion space immediately postoperatively and the implanted condition were observed. The fusion rate and the JOA score were recorded to compare the clinical outcomes. Results Two groups received 6-20 ( 15.4 ±4.2 )months follow-up. When follow-up to the end grafts were already fusion. The preoperative JOA score in group A,B [(8.40 ±0.96) scores vs. (8.33 ±1.07) scores(P ＞ 0.05)] were increased to (14.36 ±0.86)scores and (14.83 ±0.71) scores after postoperatively (P＞ 0.05),but there were statistically significant differences between preoperative and postoperative each group (P＜0.05). There were 6 cases artificial vertebrae in group A and 1 case in group B subsided asymptomaticly with 100% choiceness rate. Conclusion These two kinds of artificial vertebrae could show similar outcomes in cervical vertebral reconstruction, but the n-HA/PA66 mesh has a lower subsidence rate.

Treatment of thoracolumbar burst fractures with bioactive artificial vertebrae of nano-hydroxyapatite and polymide 66 / 中华创伤杂志

Objective To investigate the efficacy of the bioactive artificial vertebrae of a nano- hydroapatite crystals and polyamide 66 composite(n-HA/PA66)to restore the height and architecture of thoracolumbar burst fracture.Methods From December 2003 to February 2006,38 patients(29 males and 9 females)with a mean age of 35.6 years(17-63 years)were treated surgically through anterior ap- proach for decompression and implanted with the bioactive artificial vertebrae of n-HA/PA66 composite to reconstruct the structure of the thoracolumbar burst fractured vertebra.Results All the patients were successfuly followed-up for an average of 8 months,ranging from 6 to 21 months.The bioaetive artificial vertebrac of n-HA/PA66 composite were fused with the receptor bone 3-4 months after operation.The neu- rological function of the patients was restored partially or completely.The thoracolumbar spine was stable during physical examination and the height of thoraeolumbar burst fractured vertebrae that had been restored did not changa during the follow-up.Conclusions Our results show the bioaetive artificial vertebrae of n-HA/PA66 can restore the height and structure of thoracolumbar burst fractured vertebrae and reconstruct the structure of the tboraeolumbar vertebrae effectively,indicating that the bioaetive artificial vertebrae of n- HA/PA66 can be used extensively in clinical spinal surgery.

Application of nano-hydroapaic crystals and polyamide composite for artificial vertebrae to treating thoracic or lumbar vertebrae tumor / 第三军医大学学报

Objective To discuss the application of nano-hydroapatic crystals and polyamide composite(n-HA/PA66) for artificial vertebrae in treating thoracic or lumbar vertebrae tumor.Methods A total of 14 cases suffering from thoracic or lumbar vertebrae tumor underwent deuto-total vertebrae resection via anterior approach,then canalis vertebralis was deboosted,artificial vertebrae was implanted and fixed with screw-stick system.Fourteen patients,9 male and 5 female were admitted by our hospital from Dec 2003 to Sep 2005,aged 32 to 68 years old(average 50).The tumor located at T_(11) in 2 cases,T_(12) in 2,L_1 in 5,L_2 in 5.Pathological diagnosis showed 3 cases were of aneurysmal bone cyst,5 of hemangioma,2 of giant cell tumor,3 of metastatic thoracic lumbar vertebra tumor. Results The follow-up lasted 3-18 months,mean 10 months.The rate of bone graft fusion reached 85.7%,with no loosened internal fixation or breakage of screw or stick.No screw breakage or spinal instability occurred during the follow-up.All cases were alive till follow-up finished.Conclusion If the thoracic vertebral tumor compresses spinal cord seriously,the patients should be recommended for surgical treatment.Total vertebrectomy followed by reconstruction could relieve the compression caused by tumor and restore the stabilization of spine effectively.Artificial vertebrae is the ideal substitute material for bone transplantation,for it has good biocompatibility,high security,high rate of bone graft fusion and firm fixation.