Comparison of Three Grafting Options for Anterior Cervical Corpectomy and Fusion: A Retrospective 3-Arms Case Control Study.

BACKGROUND: Anterior cervical corpectomy and fusion achieves foraminal radicular and central medullary decompression and spinal stabilization in staged lesions. Many bone graft materials have been developed for the reconstruction of cervical lordosis and the restoration of intervertebral height after corpectomy. The PolyEtherKetoneEtherKetoneKetone (PEKEKK) is a semicrystalline thermoplastic polymer that can be reinforced with carbon fibers to create long and highly fenestrated rectangular cervical cages for corpectomy. This study aimed to evaluate the radiological outcomes of an innovative PEKEEKK cage compared with others grafting options. METHODS: Forty-five consecutive patients who underwent surgery with PEKEKK cages between 2017 and 2019 at a spine institution, were matched with 15 patients with a titanium mesh cylindrical cage (TMC) and 15 patients with a tricortical structural iliac bone graft. The restoration of vertebral height and cervical lordosis postoperatively, and subsidence of the construct were evaluated. Complications were reported. RESULTS: The minimal follow-up was 5.1±2years. A better, but nonsignificant, postoperative gain in height was observed for PEKEKK (+8.1 ± 20%) and TMC cages (+8.2 ± 16%) than for iliac crest autograft reconstruction (+2.3 ± 15%, P = 0.119). The mean subsidence at the last follow-up was greater for TMC cages (-10.2 ± 13%), but was not significant, with -6.1 ± 10% for PEKEKK cages and -4.1 ± 7% for iliac crest autografts (P = 0.223). The gain in segmental cervical lordosis was significant (P < 0.001) and remained stable in all the groups. CONCLUSIONS: Although an improvement in radiologic anatomical parameters can be achieved with all cage groups, the PEKEKK cage can be considered as a safe alternative for reducing subsidence.

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.

A Comparison of Corpectomy ACDF Hybrid Procedures with Nano-Hydroxyapatite/Polyamide 66 Cage and Titanium Mesh Cage for Multi-level Degenerative Cervical Myelopathy: A Stepwise Propensity Score Matching Analysis.

OBJECTIVE: Previous studies have found satisfactory clinical results with the nano-hydroxyapatite/polyamide 66 (n-HA/PA66) cage to reconstruct the stability of anterior cervical column. However, studies evaluating the long-term outcomes of the n-HA/PA66 cage in multi-level degenerative cervical myelopathy (MDCM) have not been reported. This study aims to compare the outcomes of corpectomy anterior cervical discectomy and fusion (ACDF) hybrid procedures between the n-HA/PA66 cage and titanium mesh cage (TMC) to treat MDCM. METHODS: After the screening for eligibility, this retrospective study involved 90 patients who underwent corpectomy ACDF hybrid (CACDFH) procedure from June 2013 to June 2018. The CACDFH procedure is the combination of ACDF and anterior cervical corpectomy and fusion (ACCF). According to the cage utilized, we categorized patients into a n-HA/PA66 cage group and a TMC group. Then, stepwise propensity score matching (PSM) was performed to maintain comparable clinical data between groups. All the patients were followed up ≥4 years and the longest follow-up time was 65.43 (±11.49) months. Cage subsidence, adjacent segment degeneration (ASD), segmental height (SH), segmental angle (SA), cervical lordosis (CL), and clinical data (visual analogue scale [VAS] and Japanese Orthopaedic Association [JOA] score) was evaluated preoperatively, at 1 week, and at the final surgery follow-up. The independent student's t test and chi-square test were applied to compare the differences between groups. RESULTS: Through PSM analysis, 25 patients from the n-HA/PA66 group were matched to 25 patients in the TMC group. The occurrence of ASD was 16.0% (4/25) in the n-HA/PA 66 group, which was significantly less than in the TMC group at 44.0% (11/25) (p = 0.031). Moreover, the cage subsidence rate was significantly higher in the TMC group as compared to the n-HA/PA 66 group (40.0% vs. 12.0%, p = 0.024). But there was no significant difference in SH, SA, and CL at any time after surgery as determined through follow-up. The VAS and JOA scores significantly improved in both groups at 3 months postoperative and at final follow-up. However, there were no significant differences in the VAS and JOA score at any time between the two groups in preoperative (p > 0.05). CONCLUSION: The n-HA/PA66 cage is associated with lower rate of cage subsidence and ASD than the TMC in the treatment of MDCM. The n-HA/PA66 cage could be superior to the TMC in corpectomy ACDF hybrid procedures.

Long-term outcomes of the nano-hydroxyapatite/polyamide-66 cage versus the titanium mesh cage for anterior reconstruction of thoracic and lumbar corpectomy: a retrospective study with at least 7 years of follow-up.

BACKGROUND: The nano-hydroxyapatite/polyamide-66 (n-HA/PA66) cage is a biomimetic cage with a lower elastic modulus than the titanium mesh cage (TMC). This study aimed to compare the long-term outcomes of the n-HA/PA66 cage and TMC in the anterior reconstruction of thoracic and lumbar fractures. METHODS: We retrospectively studied 113 patients with acute traumatic thoracic or lumbar burst fractures, comprising 60 patients treated with the TMC and 53 treated with the n-HA/PA66 cage for anterior reconstruction following single-level corpectomy. The radiographic data (cage subsidence, fusion status, segmental sagittal alignment) and clinical data (visual analogue scale (VAS) for pain and Oswestry Disability Index (ODI) for function) were evaluated preoperatively, postoperatively, and at final follow-up after a minimum 7-year period. RESULTS: The n-HA/PA66 and TMC groups had similar final fusion rates (96.2% vs. 95.0%). The cage subsidence at final follow-up was 2.3 ± 1.6 mm with subsidence of more than 3 mm occurring in 24.5% in the n-HA/PA66 group, which was significantly lower than the respective values of 3.9 ± 2.5 mm and 58.3% in the TMC group. The n-HA/PA66 group also had better correction of the bisegmental kyphotic angle than the TMC group (7.1° ± 7.5° vs 1.9° ± 8.6°, p < 0.01), with lower loss of correction (2.9° ± 2.5° vs 5.2° ± 4.1°, p < 0.01). The mean ODI steadily decreased after surgery in both groups. At final follow-up, the ODI and VAS were similar in the TMC and n-HA/PA66 groups. CONCLUSIONS: The n-HA/PA66 cage is associated with excellent radiographic fusion, better maintenance of the height of the fused segment, and better correction of kyphosis than the TMC during 7 years of follow-up after one-level anterior corpectomy. With the added benefit of radiolucency, the n-HA/PA66 cage may be superior to the TMC in anterior reconstruction of thoracic or lumbar fractures.

[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.

Reconstruction of critical size segmental femoral diaphyseal defects of New Zealand rabbits by using combined titanium mesh cage and induced membrane technique.

PURPOSE: Long bone defects due to fractures resulting from high-energy trauma, infections and tumor resections are problems that orthopedic surgeons commonly face. We investigated the effects of a titanium mesh cage on bone healing with an induced membrane technique. METHODS: Three groups, each composed of eight rabbits, were formed. Extraarticular diaphyseal bone defects were created. Femora of the first group were fixed with an empty titanium mesh cage and two K-wires. After formation of the defect, polymethylmethacrylate was inserted and fixed with a K-wire in the second group. At the third week, the cement was removed, a sterilized cancellous graft-filled titanium mesh cage was placed into the defect, and the membrane that was previously formed over the cement was placed on the cage and repaired. In the third group, sterilized cancellous grafts were filled into the titanium mesh cage, and the titanium mesh cage was fitted into the bone defect area. RESULTS: At the end of the third month, all subjects were killed. Radiological data revealed that the healing of the bone in the second and third groups was significantly better than that in the first group. There was no difference between the second and third groups. A histological evaluation of the healing status, such as fibrous tissue, cartilage tissue and mature or immature bone formation, was performed. Histological healing in the second and third groups was also significantly better than that in the first group. CONCLUSION: We concluded that the combination of membrane-induced bone healing and graft-filled titanium mesh cages expedites osteogenesis in extraarticular bone defects.

3D-printed vertebral body in anterior spinal reconstruction after total spondylectomy for patients with cervical chordoma / 北京大学学报(医学版)

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.

Is 3D-printed prosthesis stable and economic enough for anterior spinal column reconstruction after spinal tumor resection? A retrospective comparative study between 3D-printed off-the-shelf prosthesis and titanium mesh cage.

OBJECT: To investigate the stability and cost-effectiveness of the three-dimensional-printed (3DP) off-the-shelf (OTS) prosthesis in the reconstruction of the anterior column of the thoracic/lumbar spine after tumor resection. METHODS: Thirty-five patients (26 with primary malignant tumors and nine with metastatic malignant tumors) who underwent tumor resection and anterior column reconstruction between January 2014 and January 2019 were included in a single institute. Patients were divided into the 3DP OTS prosthesis (3DP) group (n = 14) and the titanium mesh cage (TMC) group (n = 21) by the type of implant. The operation time, intraoperative blood loss, hospital stay, history of radiotherapy, surgical level and total cost were collected and compared between the two groups. Mechanical complications and radiological parameters including mean vertebral height, subsidence, fixation failure(nonunion, migration, screw loosening, rod breakage) rate were recorded at preoperation, 1 week, 3 months, 6 months, 12 months after surgery then at 1 year interval or stop until the end of survival. The follow-up patients were also sent with short form-36 to assess their health-related quality of life (HRQoL) and questions about the current condition of their disease. RESULTS: The mean overall follow-up was 24.6 months. Of the 35 patients involved, six patients died and six were lost to follow-up. The differences between the two groups in operative time, intraoperative blood loss, and hospital stay were not statistically significant (p > 0.05). The differences in fixation failure and the subsidence rate between the two groups were not statistical significant (p > 0.05). The difference of subsidence rate between the cases with and without osteoporosis, cases with and without radiotherapy was statistically significant within each group (p < 0.05). However, the difference of subsidence rate between the surgical level above or below T10 was not statistically significant (p > 0.05). The response rate of the questionnaire among the survived patients was 100% (23/23 patients). The results of the Short Form- (SF-)36 between the two groups were similar (p > 0.05). The total cost was higher in the 3DP group (p < 0.05) with its higher graft cost (p < 0.05), but the differences in internal fixation cost and other cost were not statistically significant between groups (p > 0.05). CONCLUSION: Compared to TMC, the 3DP OTS prosthesis achieved similar clinical and radiological results in spinal anterior spinal column reconstruction of thoracic/lumbar spinal tumor resection. However, the 3DP OTS prosthesis was more expansive than TMC.

Surgical treatment was desirable to improve neuromuscular function in patients with sustained 3 years fracture-dislocation of lower cervical spine: A case report.

To investigate the changes in neuromuscular function of anterior approach combined with subtotal vertebral body resection and titanium mesh cage (TMC) internal fixation for the old fracture-dislocated lower cervical spine. A 56-year-old female was admitted to the hospital with neck pain and numbness of the left upper extremity for 3 years due to a fall injury from a height, which worsened for 20 days. Although 3 years had passed, the patient still had significant left limb numbness and decreased muscle strength. Eventually, the patient was diagnosed with the old fracture-dislocation type injury of C6 and C7. C6 was II-degree anterior dislocation and the bilateral joint process was locked, C7 was burst fracture, and C5 was spinal cord segment injury. Then, the operation of the anterior approach combined with subtotal vertebral body resection and TMC internal fixation was performed under general anesthesia. Postoperative symptoms were significantly improved. And during five-year of follow-up, no adverse reactions and complications were reported. Although cervical fracture and dislocation combined with cervical spinal cord injury had persisted for many years, surgical treatment was necessary. The anterior approach combined with subtotal vertebral body resection and TMC internal fixation was desirable to improve neuromuscular function for the old fracture-dislocation of the lower cervical spine, which has some guiding effects on the clinical treatment.

Factors affecting titanium mesh cage subsidence in single-level anterior cervical corpectomy and fusion for ossification of the posterior longitudinal ligament.

PURPOSE: To analyze risk factors of titanium mesh cage (TMC) subsidence in single-level anterior cervical corpectomy and fusion (ACCF) for cervical ossification of the posterior longitudinal ligament (OPLL). METHODS: TMC subsidence is defined as the reduction of the adjacent vertebral bodies by ≥ 2 mm. Patients with cervical OPLL who were treated with single-level ACCF between January 2019 and May 2021 were retrospectively analyzed in two groups: patients with TMC subsidence as Group S and patients with no TMC subsidence as Group N during the one-year follow-up period. The degree of distraction of surgical segment and correction of the cervical curvature was measured to analyze their relationship with TMC subsidence. RESULTS: A total of 128 patients were included in Group S, and 138 patients were included in Group N. There was no significant difference in patient demographics and complications between the two groups. The degree of distraction in Group S was significantly higher than that in Group N (11.4% ± 7.6% vs. 4.7% ± 9.7%, P < 0.01). The change of C2 to C7 Cobb angle (α) in Group S was significantly greater than that in Group N (5.7 ± 2.7 vs. 1.4 ± 4.7, P < 0.01), and the change of interspinous process distance (SPD) in Group S was also significantly greater than that in Group N (7.0 ± 4.2 vs. 4.1 ± 2.7, P < 0.01). The JOA score and JOA recovery rate were not statistically different between the two groups. CONCLUSIONS: Intraoperative selection of overlength TMC in single-level ACCF for OPLL, over-distraction and excessive correction of the cervical curvature may cause TMC subsidence after surgery. No significant impact of TMC subsidence on the surgical outcome was observed during the 1-year follow-up period.