Comparison of clinical efficacy of 3D-printed artificial vertebral body and conventional titanium mesh cage in spinal reconstruction after total en bloc spondylectomy for spinal tumors: a systematic review and meta-analysis

Propose

This meta-analysis aimed to determine whether 3D-printed artificial vertebral bodies (AVBs) have superior clinical efficacy compared to conventional titanium mesh cages (TMCs) for spinal reconstruction after total en bloc spondylectomy (TES) for spinal tumors.

Methods

Electronic databases, including PubMed, OVID, ScienceDirect, Embase, CINAHL, Web of Science, Cochrane Library, WANFANG, and CNKI, were searched to identify clinical trials investigating 3D-printed AVB versus conventional TMC from inception to August 2023. Data on the operation time, intraoperative blood loss, preoperative and postoperative visual analogue scale (VAS) scores, preoperative and postoperative Frankel classification of spinal cord injury, vertebral body subsidence, and early complications were collected from eligible studies for a meta-analysis. Data were analyzed using Review Manager 5.4 and Stata 14.0.

Results

Nine studies assessing 374 patients were included. The results revealed significant differences between the 3D-printed AVB and conventional TMC groups with regard to operation time (P = 0.04), intraoperative blood loss (P = 0.004), postoperative VAS score (P = 0.02), vertebral body subsidence (P < 0.0001), and early complications (P = 0.02). Conversely, the remaining preoperative VAS score and Frankel classifications (pre-and postoperative) did not differ significantly between the groups.

Conclusion

The 3D-printed AVB in spinal reconstruction after TES for spinal tumors has the advantages of a short operative time, little intraoperative blood loss, weak postoperative pain, low occurrence of vertebral body subsidence and early complications, and a significant curative effect. This could provide a strong basis for physicians to make clinical decisions.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023441521, identifier CRD42023441521.

Surgical outcomes and risk factors for surgical complications after en bloc resection following reconstruction with 3D-printed artificial vertebral body for thoracolumbar tumors

BACKGROUND

The outcomes of patients with tumors of the thoracolumbar spine treated with en bloc resection (EBR) using three-dimensional (3D)-printed endoprostheses are underreported.

METHODS

We retrospectively evaluated patients with thoracolumbar tumors who underwent surgery at our institution. Logistic regression analysis was performed to identify the potential risk factors for surgical complications. Nomograms to predict complications were constructed and validated.

RESULTS

A total of 53 patients with spinal tumors underwent EBR at our hospital; of these, 2 were lost to follow-up, 45 underwent total en bloc spondylectomy, and 6 were treated with sagittal en bloc spondylectomy. The anterior reconstruction materials included a customized 3D-printed artificial vertebral body (AVB) in 10 cases and an off-the-shelf 3D-printed AVB in 41 cases, and prosthesis mismatch occurred in 2 patients reconstructed with the off-the-shelf 3D-printed AVB. The median follow-up period was 21 months (range, 7-57 months). Three patients experienced local recurrence, and 5 patients died at the final follow-up. A total of 50 perioperative complications were encountered in 29 patients, including 25 major and 25 minor complications. Instrumentation failure occurred in 1 patient, and no prosthesis subsidence was observed. Using a combined surgical approach was a dependent predictor of overall complications, while Karnofsky performance status score, lumbar spine lesion, and intraoperative blood loss ≥ 2000 mL were predictors of major complications. Nomograms for the overall and major complications were constructed using these factors, with C-indices of 0.850 and 0.891, respectively.

CONCLUSIONS

EBR is essential for the management of thoracolumbar tumors; however, EBR has a steep learning curve and a high complication rate. A 3D-printed AVB is an effective and feasible reconstruction option for patients treated with EBR.

A Novel Technology for 3D-Printing Artificial Vertebral Bodies for Treating Lumbar Spine Adrenal Pheochromocytoma Metastases: A Case Report and Review of the Literature

BACKGROUND

Pheochromocytoma is an adrenal medullary neuroendocrine tumor that rarely metastasizes to the spine. Currently, its specific treatment methods still present challenges.

CASE DESCRIPTION

A 41-year-old male patient who underwent left total adrenalectomy due to pheochromocytoma 3 years ago presented with lower back pain, accompanied by numbness and decreased muscle strength in both legs, as well as decreased sensation. Abnormal transmittance of the L3 vertebral body could be seen on anterior-posterior and lateral lumbar X-rays, irregular bone destruction of the L3 vertebral body was found on CT, and an MRI scan showed that the tumor was located within the L3 vertebral body, protruding into the spinal canal and compressing the epidural sac. No recurrence was found in the abdomen. Preoperatively, perform local embolization of the blood vessels supplying the tumor. First, the L2-3 intervertebral disc, L3-4 intervertebral disc and L3 vertebral body were removed using an anterior approach, the whole tumor was removed, and some of the vertebrae were taken for pathological examination and replaced with a 3D-printed prosthesis. Then, four pedicle screws were placed in the bilateral pedicles of L2 and L4 using the posterior approach, pre-bent connecting rods were installed to replace the bone cortex of the lamina and articular process followed by bone graft fusion of the interlaminar and facet joints. The postoperative results were satisfactory, and there were no perioperative complications.

CONCLUSION

Lumbar pheochromocytoma metastasis is rare, difficult to treat, and should be considered in spinal metastases' differential diagnoses so early diagnosis can be made based on medical history and imaging. Preoperative local vascular imaging and embolization of the blood supply vessels were performed. After total en-bloc spondylectomy of the tumor during surgery, a prosthesis was implanted and combined with pedicle screw fixation to reconstruct spinal biomechanical stability, achieving satisfactory results. Therefore, 3D printed artificial vertebral bodies are a good choice for treating adrenal pheochromocytoma lumbar metastasis. The key to successful treatment is close interdisciplinary collaboration in formulating rigorous comprehensive perioperative plans.

[3D-printed vertebral body in anterior spinal reconstruction after total spondylectomy for patients with cervical chordoma]

OBJECTIVE

To investigate whether 3D-printed artificial vertebral body can reduce prosthesis subsidence rate for patients with cervical chordomas, through comparing the rates of prosthesis subsidence between 3D printing artificial vertebral body and titanium mesh for anterior spinal reconstruction after total spondylectomy.

METHODS

This was a retrospective analysis of patients who underwent surgical treatment for cervical chordoma at our hospital from March 2005 to September 2019. There were nine patients in the group of 3D artificial vertebral body (3D group), and 15 patients in the group of titanium mesh cage (Mesh group). The patients' characteristics and treatment data were extracted from the medical records, including age, gender, CT hounsfield unit of cervical vertebra and surgical information, such as the surgical segments, time and blood loss of surgery, frequency and degree of prosthesis subsidence after surgery. Radiographic observations of prosthesis subsidence during the follow-up, including X-rays, CT, and magnetic resonance imaging were also collected. SPSS 22.0 was used to analysis the data.

RESULTS

There was no significant difference between the two groups in gender, age, CT hounsfield unit, surgical segments, time of surgery, blood loss of posterior surgery and total blood loss. Blood loss of anterior surgery was 700 (300, 825) mL in 3D group and 1 500 (750, 2 800) mL in Mesh group (P < 0.05). The prosthesis subsidence during the follow-up, 3 months after surgery, there was significant difference between the two groups in mild prosthesis subsidence (P < 0.05). The vertebral height of the 3D group decreased less than 1 mm in eight cases (no prosthesis subsidence) and more than 1 mm in one case (mild prosthesis subsidence). The vertebral height of the Mesh group decreased less than 1 mm in five cases (no prosthesis subsidence), and more than 1 mm in eight cases (mild prosthesis subsidence). Two patients did not have X-rays in 3 months after surgery. There was a statistically significant difference between the two groups in the prosthesis subsidence rate at the end of 12 months (P < 0.01). The vertebral height of eight cases in the 3D group decreased less than 1 mm (no prosthesis subsidence) and one case more than 3 mm (severe prosthesis subsidence). Four of the 15 cases in the Mesh group decreased less than 1 mm (no prosthesis subsidence), two cases more than 1 mm (mild prosthesis subsidence), and nine cases more than 3 mm (severe prosthesis subsidence). There was a statistically significant difference between the two groups in the prosthesis subsidence rate at the end of 24 months (P < 0.01). The vertebral height of seven cases in the 3D group decreased less than 1 mm (no prosthesis subsidence), one case more than 3 mm (severe prosthesis subsidence), and one case died with tumor. One case in the Mesh group decreased less than 1 mm (no prosthesis subsidence), one case more than 1 mm (mild prosthesis subsidence), 11 case more than 3 mm (severe prosthesis subsidence), one case died with tumor and one lost the follow-up. Moreover, at the end of 12 months and 24 months, there was significant difference between the two groups in severe prosthesis subsidence rate (P < 0.01).

CONCLUSION

3D-printed artificial vertebral body for anterior spinal reconstruction after total spondylectomy for patients with cervical chordoma can provide reliable spinal stability, and reduce the incidence of prosthesis subsidence after 2-year follow-up.

Comparison of radiological and clinical outcomes of 3D-printed artificial vertebral body with Titanium mesh cage in single-level anterior cervical corpectomy and fusion: A meta-analysis

Propose

This meta-analysis aimed to determine whether 3D-printed artificial vertebral body have superior clinical and radiographic outcome than Titanium Mesh Cage(TMC) in single-level anterior cervical corpectomy and fusion.

Methods

A comprehensive search of the PubMed, Embase, Cochrane Library, Web of Science, and CNKI (China National Knowledge Infrastructure) databases was conducted to find randomized control trials (RCTs) or cohort studies that compared 3D-printed artificial vertebral body with conventional Titanium Mesh Cage (TMC) in single-level anterior cervical corpectomy and fusion (SL-ACCF). Operation time; intraoperative blood loss; subsidence of vertebral body; preoperative, and final follow-up C2-C7 Cobb angle, Japanese Orthopedic Association (JOA) scores, and Visual Analog Scale(VAS) scores were collected from eligible studies for meta-analysis.

Results

We included 6 cohort studies with 341 patients. The results of the meta-analysis showed that the 3D group has a shorter operation time than the traditional TMC group(p = 0.04) and the TMC group had more severe subsidence(≥3 mm) of vertebral body than the 3D group(p < 0.0001). And the cervical C2-C7 Cobb angle in the 3D group was larger than that in the TMC group at the final follow-up.

Conclusion

This meta-analysis demonstrates that 3D-printed artificial vertebral body is superior to traditional TMC in reducing the operation time and maintaining the postoperative vertebral height and restoring sagittal balance to the cervical spine in single-level anterior cervical corpectomy and fusion.