Objective:To explore the advantages of the novel individualized 3D printing artificial vertebral body in spine reconstruction and to evaluate its clinical effect.Methods:From January 2017 to December 2018, the 15 patients who underwent total vertebrectomy and spine reconstruction with individualized 3D printing artificial vertebral body were analyzed retrospectively. There were 8 males and 7 females, with the mean age 39.5 years (range: 20-57), including 12 primary tumors and 3 metastatic tumors. According to tumor location and surrounding soft tissue invasion range, simple posterior or combined anterior and posterior approach were used for total vertebral resection, and the defection was reconstructed by 3D printing artificial vertebral body. The operation time, intraoperative bleeding volume, postoperative stability of artificial vertebral body and bone ingrowth of adjacent vertebral body, preoperative and postoperative neurological changes, preoperative and postoperative VAS score, local control and survival of patients were analyzed.Results:The mean operation time was 412.0 min (range: 135-740 min), and the mean blood loss was 4 140.0ml (range: 100-14 000 ml). The mean follow-up time was 23.2 months (range: 12-35 months), and no one loss to follow-up. One case had pleural rupture, one case had cerebrospinal fluid leakage and one case had L5 nerve root palsy. All patients recovered after active symptomatic treatment. Compare with the preoperative VAS score (4.7±1.1), the differences of VAS score at 7 d postoperative and last follow-up (1.6±0.6 and 1.0±0.5) were significantly reduced ( P<0.001). Three patients with Frankel grade C gradually recovered to grade D, and no change were found in grade D and Grade E patients, there was no significant improved at last follow-up. Preliminary bone growth was found between the artificial vertebral body and the adjacent vertebral body 3 months after operation. The bone growth was more obvious at 12 months post-operation, and the artificial vertebral body fused with the adjacent vertebral bodies to form bone integration. At 24 months post-operation, the integration of the artificial vertebral body was more accurate. During the follow-up period, there was no loosening or displacement of the artificial vertebral body and no failure of internal fixation. A case of hemangioendothelioma and a case of epithelioid angiosarcoma died at 33 months and 35 months postoperatively. One patient with chondrosarcoma had local recurrence at16 months post-operation. After treated with arotinib, the tumor did not progress. The other 12 patients had no tumor recurrence or distant metastasis. Conclusion:After spinal tumor resection, individualized 3D printing artificial vertebral body can be used to accurate restoration of spinal continuity, and provide nice interface matching and bone growth between artificial vertebral body and the adjacent vertebral endplates. Moreover, the immediate and long-term stability of the artificial vertebral body can meet the needs of spinal reconstruction.

Objective:To analyze the radiographic parameters of shoulder balance that affect the postoperative satisfaction of Lenke type 1 adolescent idiopathic scoliosis (AIS).Methods:A total of 98 patients with AIS who underwent posterior pedicle screw fusion in Xijing Hospital of Air Force Medical University from August 2017 to July 2020 were retrospectively analyzed. There were 26 males and 72 females, aged 15.2±5.3 years (range, 10-24 years). Distribution of upper instrumented vertebrae: T 2 58 cases (59%), T 3 25 cases (26%), T 4 15 cases (15%); Distribution of lower instrumented vertebrae: T 12 63 cases (64%), L 1 28 cases (29%), L 2 4 cases (4%), L 3 3 cases (3%). Clavicle angle (CA), radiographic shoulder height (RSH), and coracoid height difference (CHD), clavicle-rib cage intersection difference (CRID), T 1 tilt angle, first rib tilt angle, clavicle chest angle difference(CCAD) and Scoliosis Research Society-22 (SRS-22) scale were compared before and after operation. Binary logistic regression was used to analyze the radiographic indicators of shoulder balance that affected the postoperative satisfaction of Lenke type 1 AIS. The receiver operating characteristic (ROC) curve was drawn to determine the threshold value of the imaging index. Results:All operations were successfully completed. The operation time was 260±80 min (range, 220-320 min), and the intraoperative blood loss was 360±110 ml (range, 300-700 ml). There was no nerve, dural or vascular injury during operation. RSH, CHD, CRID, T 1 tilt angle, first rib tilt angle, and CCAD at the final follow-up were 4.0 (0, 13.9) mm, 7.0 (0, 12.9) mm, 4.0 (0, 10.0) mm, 4.8° (3.3°, 8.2°), 5.3°±3.9°, and 5.5° (3.0°, 8.9°), respectively, which were less than the preoperative 10.6 (2.0, 20.3) mm, 10.3 (2.5, 15.9) mm, 8.0 (1.0, 15.2) mm, 7.6° (3.5°, 12.2°), 7.5°±6.9°, 8.5° (3.6°, 18.3°), and the difference was statistically significant ( P<0.05). The SRS-22 function, pain, appearance, and psychological scores at the final follow-up were 4.6 (4.0, 4.9), 4.1±0.5, 4.1±0.7, and 4.2 (3.9, 4.8) points, respectively, which were greater than the preoperative scores of 4.2 (3.8, 4.6), 4.0±0.7, 3.5±0.7, and 4.0 (3.5, 4.4) points, the difference was statistically significant ( P<0.05). Binary logistic regression showed that CCAD was an independent radiographic indicator of shoulder balance that affected the satisfaction of AIS patients after orthopaedic surgery ( OR=0.826, P=0.040). ROC curve showed that the area under the curve and 95% CI was 0.726 (0.572, 0.865), and the threshold was 6.6°. Conclusion:CCAD is an independent radiographic parameter of shoulder balance that affects the postoperative satisfaction of AIS. Patients are more likely to achieve a satisfactory outcome when their postoperative CCAD is ≤6.6°, which can be used clinically as a radiographic parameter to assess the efficacy of orthopaedic spine surgery.