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.

Recent Advances of Biomechanical Studies on Cervical Spine Anatomy and Titanium Mesh Cage / 医用生物力学

Titanium mesh cage is one of the fusion devices used in anterior cervical corpectomy and fusion (ACCF). It can not only immediately rebuild the stability of cervical spine during the operation, maintain the height and physiological curvature of intervertebral vertebrae, but also avoid the complications of bone donor area caused by autologous bone extraction. Therefore, titanium mesh cage has become the most commonly used internal plant in ACCF. However, there exist many problems in traditional titanium cage, such as stress shielding and titanium cage sinking, which will affect the surgical effect to a certain extent, and even lead to serious postoperative complications requiring revision surgery. At present, a variety of new titanium cages have been invented, which can solve the problems caused by traditional titanium cage to a certain extent. Biomechanical evaluation and its testing methods are an indispensable process for judging whether a new type of spinal fusion cage can be used in clinical practice. This article reviews the biomechanical studies related to cervical spine anatomy, the biomechanical properties of traditional titanium cages and new titanium cages, so as to provide new ideas for the improvement of traditional titanium cages and the development of new titanium cages.

Effects of a new anatomical adaptive titanium mesh cage on supportive load at the cervical endplate: a morphological and biomechanical study / 南方医科大学学报

OBJECTIVE@#To assess the geometrical matching of a new anatomical adaptive titanium mesh cage (AA-TMC) with the endplate and its effect on cervical segmental alignment reconstruction in single- and two-level anterior cervical corpectomy and fusion (ACCF) and compare the compressive load at the endplate between the AA-TMC and the conventional titanium mesh cage (TMC).@*METHODS@#Twelve cervical cadaveric specimens were used to perform single- and two-level ACCF. The interbody angle (IBA), interbody height (IBH) and the interval between the AA-TMC and the endplate were evaluated by comparison of the pre- and postoperative X-ray images. The maximum load at the endplate was compared between the AA-TMC and TMC based on American Society for Testing and Materials (ASTM) F2267 standard.@*RESULTS@#No significant differences were found between the preoperative and postoperative IBA and IBH in either single-level ACCF (11.62°±2.67° 12.13°±0.69° and 23.90±2.18 mm 24.23±1.13 mm, respectively; > 0.05) or two-level ACCF (15.63°±5.06° 16.16°±1.05°and 42.93±3.51 mm 43.04±1.70 mm, respectively; > 0.05). The mean interval between the AA-TMC and the endplate was 0.37 ± 0.3 mm. Compared to the conventional TMC, the use of AA-TMC significantly increased the maximum load at the endplate in both single-level ACCF (719.7±5.5 N 875.8±5.2 N, < 0.05) and two-level ACCF (634.3±5.9 N 873±6.1 N, < 0.05).@*CONCLUSIONS@#The use of AA-TMC in single-level and two-level ACCF can significantly increase the maximum load at the endplate to lower the possibility of implant subsidence and allows effective reconstruction of the cervical alignment.

Comparison of 3D printed cervical spine with titanium mesh cage for fractures of lower cervical spine / 中华创伤骨科杂志

Objective To compare the effectiveness of 3D cervical spine versus titanium mesh cage in the treatment of fractures of lower cervical vertebrae.Methods From May 2016 to March 2017,a total of 31 patients with cervical spine fracture were enrolled in this prospective randomized controlled trial at Department of Orthopaedics,Luohe Central Hospital.Of them,16 cases were randomized to receive anterior cervical sub-total resection and decompression followed by internal fixation with implant of 3D printed cervical spine (3D group) and 18 to receive anterior cervical sub-total resection and decompression followed by internal fixation with implant of titanium mesh cage (TM group).The 2 groups were compared in terms of operation time,intraoperative bleeding,score and improvement rate of Japanese Orthopaedic Association (JOA),vertebral height change,cobb angle change and bone graft fusion.Results Eventually,included for this study were 15 cases in the 3D group and 16 in the TM group who had been completely followed up.Operations were well done for all the patients.The operation time for the 3D group (83.9 ± 21.4 min) was significantly shorter than that for the TM group (116.2 ± 27.8 min) (t =5.039,P ＜ 0.001).There was no significant difference between the 2 groups in intraoperative bleeding (92.6 ± 25.4 mL versus 105.6 ± 21.7 mL) (t =0.950,P =0.350).Follow-ups for 6 to 15 months revealed no implants failure or displacement in either group.By the final follow-up,bony union was achieved in all.Their preoperative JOA scores were all improved at the final follow-ups.There was no significant difference in JOA scores between the 2 groups (P ＞0.05).The vertebral heights and cobb angles at postoperative 3 months and at the final follow-up in the 3D group were significantly larger than those in the TM group (P ＜ 0.05);the vertebral heights and cobb angles at postoperative 3 months and at the final follow-up were significantly improved than the preoperative values in all the patients (P ＜ 0.05);there was no significantly difference between the vertebral height and cobb angle at postoperative 3 months and those at the final follow-up in either group (P ＞ 0.05).The incidence of prosthesis settlement in the 3D group (6.7％) was significantly lower than that in the TM group (43.75％)(P ＜ 0.05).Conclusions Both surgical procedures can reconstruct cervical stability.Compared with titanium mesh cage,3D printed cervical spine may lead to shorter operation time,better bone-material bonding interface,less prosthesis sinking and superiority in maintaining the cervical height and curvature.

Clinical Significance of Radiological Stability in Reconstructed Thoracic and Lumbar Spine Following Vertebral Body Resection

OBJECTIVE: Vertebral body replacement following corpectomy in thoracic or lumbar spine is performed with titanium mesh cage (TMC) containing any grafts. Radiological changes often occur on follow-up. This study investigated the relationship between the radiological stability and clinical symptoms. METHODS: The subjects of this study were 28 patients who underwent corpectomy on the thoracic or lumbar spine. Their medical records and radiological data were retrospectively analyzed. There were 23 cases of tumor, 2 cases of trauma, and 3 cases of infection. During operation, spinal reconstruction was done with TMC and additional screw fixation. We measured TMC settlement in sagittal plane and spinal angular change in coronal and sagittal plane at postoperative one month and last follow-up. Pain score was also checked. We investigated the correlation between radiologic change and pain status. Whether factors, such as the kind of graft material, surgical approach, and fusion can affect the radiological stability or not was analyzed as well. RESULTS: Mean follow-up was 23.6 months. During follow-up, 2.08+/-1.65degrees and 6.96+/-2.08degrees of angular change was observed in coronal and sagittal plane, respectively. A mean of cage settlement was 4.02+/-2.83 mm. Pain aggravation was observed in 4 cases. However, no significant relationship was found between spinal angular change and pain status (p=0.518, 0.458). Cage settlement was seen not to be related with pain status, either (p=0.644). No factors were found to affect the radiological stability. CONCLUSION: TMC settlement and spinal angular change were often observed in reconstructed spine. However, these changes did not always cause postoperative axial pain.

A Comparison of Clinical and Radiological Outcome Between Two-Level Discectomy and One-Level Corpectomy for Cervical Degenerative Disc Disease

OBJECTIVE: The clinical and radiographic success of a two-level discectomy and autologous iliac bone fusion with anterior cervical plate fixation (ACDFP) was compared with that of a one-level corpectomy and fusion using a titanium mesh cage (corpectomy) for the treatment of degenerative cervical disc disease. METHODS: From January 2004 to December 2007, there were 45 consecutive cases of two disc level degenerative cervical disc disease treated with either ACDFP or corpectomy. The medical records and radiological studies were reviewed, retrospectively. The clinical outcomes were measured using Odom's criteria. The radiologic assessment was performed using images showing the lordosis and bony fusion. RESULTS: Twenty-seven patients were treated with ACDFP. Eighteen patients were treated with corpectomy. The clinical outcome was excellent or good in 25 cases (93%) and 17 cases (94%) treated with ACDFP and corpectomy, respectively. The fusion rate was 96% and 94% for ACDFP and corpectomy, respectively. There was a slight increase in the cervical lordosis in both groups, but there was no significant difference between the 2 groups. There were no irriversible complications in both groups. Reversible complications were encountered in 1 case of corpectomy, and 7 cases of ACDFP, which were mainly associated with donor site. CONCLUSION: Either a ACDFP or a corpectomy provides good clinical outcome and similar bone fusion rates for degenerative disc diseases. However, absence of donor site complications makes a corpectomy better than ACDFP.

Preliminary Surgical Result of Cervical Spine Reconstruction with a Dynamic Plate and Titanium Mesh Cage

OBJECTIVE: The objective of this study was to validate the effects of a titanium mesh cage and dynamic plating in anterior cervical stabilization after corpectomy. METHODS: A retrospective study was performed on 31 consecutive patients, who underwent anterior cervical reconstruction with a titanium mesh cage and dynamic plating, from March 2004 to February 2006. Twenty-four patients had 1-level and 7 had 2-level corpectomies. Ten patients underwent surgery with a cage of 10-mm diameter and 21 with 13-mm diameter. Neurological status and outcomes were assessed according to Odom's criteria. Sagittal angle, coronal angle, settling ratio, sagittal displacement, and cervical lordosis were used to evaluate the radiological outcomes. RESULTS: In overall, 26 (83.9%) of 31 showed excellent or good outcomes. Thirteen percent (4 cases) of the patients developed surgical complications, such as hoarseness, transient dysphagia, or nerve root palsy. Seven (22.6%) patients had reconstruction failure : 5 (20.8%) in the 1-level corpectomy group and 2 (28.5%) in the 2-level corpectomy group. Revisions were required in 2 patients with plate pullout due to significant instability. However, none of 5 patients who demonstrated cage displacement or screw pullout, underwent a revision. Radiographs revealed bony consolidation in 96.3% of the patients, including 6 patients with implantation failure during the follow-up period. CONCLUSION: Based on our preliminary results, the titanium mesh cage and dynamic plating was effective for cervical reconstruction after corpectomy. The anterior cervical reconsrtruction performed with dynamic plates is considered to reduce stress shielding and greater graft compression that is afforded by the unique plate design.

Anterior and posterior combined operation for treatment of lumbar tuberculosis / 中国矫形外科杂志

[Objective] To determine the efficacy of one-stage posterior deformity correction with transpedicular screw system and anterior radical debridement following reconstuction with titanium mesh cage for treatment of lumbar tuberculosis. [Methods]Forty-three patients with lumbar tuberculosis were treated operatively through anterior and posterior combined approach.The postoperative neurologic status (ASIA,2000),graft fusion,deformity correction and complications were observed and analyzed respectively.[Results]Forty-one patients were followed up for a duration of 24~36 months (mean 28.3 months).A solid fusion was achived in all cases.The neurologic function was improved in all patients in different grades.The mean kyphotic angle was corrected by 21.3 degrees,the angle loss was 1?~3?,the mean vertebral height was restored by 10.2 mm,the mean height loss was 2.4 mm.There was no recurrence of the tuberculosis infection.[Conclusion]One-stage posterior deformity correction with transpedicular screw system and anterior radical debridement following reconstuction with titanium mesh cage is a safe and effective method in the surgical management of lumbar tuberculosis.

Cervical reconstruction after anterior cervical decompression / 中国矫形外科杂志

It is of great importance for surgery efficacy and avoidance of complications to reconstruct cervical curve, intervertebral height and cervical stability. Anterior cervical decompression includes discectomy and subtotal corpectomy. The former reconstruction comprises simple bone graft, bone graft with plating, cage implantation, cage with plating and total disc replacement.The latter comprises simple bone graft, bone graft with plating, titanium mesh cage with plating, conbinding cage and titanium mesh cage with plating. The common problem is loss of intervertebral height or nonunion occurring in a part of patients.Total disc replacement may preserve motion of affected levels but narrow indication. Based in the decompression, the best method should be choosen to reconstruct cervical stability and intervertebral height.

Primary clinical application of new pterygo-shape titanium mesh cage in surgical procedure of cervical spondylosis / 中国矫形外科杂志

[Objective]To apply interal fixation with new pterygo-shape titanium mesh cage in the treatment of degenarative cervical spondylosis.[Method]Twenty-seven patients of degenarative cervical spondylosis were reconstructed after vertecotomy with the cage including 19 cases of CDH,8 cases of OPLL,18 cases in male and 9 cases in female;single segment degenaration were 21 cases,double segment degenaration were 6 cases.All cases were excluded fracture,dislocate by X-ray and MRI preoperatly.[Result]All 27 patients were followed up for an average time of 10 months(from 6 to 14 months).The anverage time of bone graft fusion was 10 weeks.[Conclusion]The pterygo_shape titanium mesh cage can provide immediate biomechanical stability and prevent the mesh cage displace,subsidence,exodus after operation.The surgical procedure is simple,safety and without illic-bone graft,meanwhile can greatly relieve patients' economy burden.Then the internal fixation is elastic fixation,the bone fusion shows a satisfactory result.

One-stage anterior radical debridement,titanium mesh bone fusion and internal fixation for the treatment of thoracolumbar spinal tuberculosis / 中国矫形外科杂志

[Objective]To evaluate the curative effect of the one-stage anterior radical debridement,titanium mesh cage bone fusion and inernal fixation for the treatment of thoracolumbar spinal tuberculosis.[Method]Twenty-two thoracolumbar spinal tuberculosis cases from January 2003 to February 2006 were analyzed retrospectively,among whom 12 were male and 10 were female,age ranging from 19 to 76 years with a mean of 36 years.T_9~L_5 vertebrae were involved in,in detail 1 was involved in single vertebra,17 were involved in 2 vertebrae,3 were involved in 3 vertebrae,1 was involved in the type of jumping style,M=2,Q=0.All cases received one-stage anerior radical debridement,titanium mesh cage bone fusion and internal fixation along with strict anti-tuberculosis chemical therapies.The improvement of symptoms and neurological function,angles reduced by the surgeries and bone fusion,angles lost as well as the subsidence of the titanium mesh during the long-term follow-up were observed and compared statistically.[Result]No recurrence was found in the follow-up period extending from 6 months to 24 months with an averaging of 12.5 months.All the incisions acquired primary healing.The systematic and local symptoms were released postoperatively.Neurological function recovered in different degrees(P

Treatment of thoracolumbar malignant neoplasms by one stage anterior-posterior approach total spondylectomy and spinal reconstraction / 中国矫形外科杂志

[Objective]To study the curative effect and superiority of one stage anterior-posterior approach total spondylectomy and spinal reconstraction in the treatment of thoracolumbar malignant neoplasms.[Method]Twenty-four thoracolumbar malignant neoplasms patients treated by anterior approach total spondylectomy,spinal reconstractin with titanium mesh cage associated with bone graft or bone cement and posterior approach transpediuclar screw fixation.[Result]The follow-up of postoperation was from 9 to 35 months.All patients achieved relieve of pain after surgery,9 cases with incomplete paraplegia improved by 1.8 grades in average with Frankel neurological classifications,2 cases with dysfunction of urination and defecation were recovered,4 patients decease for metastasis in critical organ,all the patients showed bony fusion at 6~9 months,no internal fixation loosening or breakage case was found,1 case was recrudescent after one year.[Conclusion]Treatment of thoracolnmbar malignant neoplasms by one stage anterior-posterior approach total spondylectomy and spinal reconstraction can remove the neoplasms efficiently,reconstraction the spinal stabilization and improve the quality of life.

The Efficacy of Titanium Mesh Cage in Tuberculous Spondylitis Treated with Anterior Intervertebral Fusion

OBJECTIVE: The maintenance of the correction of kyphotic deformity is one of the difficult problem in tuberculous spondylitis after anterior debriment and fusion with tricortical bone graft. The goal of this study is to find out the efficacy of titanium mesh cage impacted with autogenous bone chip in tuberculous spondylitis treated with anterior intervertebral fusion. MATERIALS AND METHODS: Twelve patients were treated with anterior intervertebral fusion using titanium mesh cage for tuberculous spondylitis from January 1996 to June 1999. We analized the changes in the correction of kyphotic deformity, changes of ESR and CRP, fusion state and recurrence after anterior intervertebral fusion with titanium mesh cage. RESULTS: Clinical symptoms were improved in all twelve patients without any neurologic complications. The mean kyphotic angle corrected was 7.3 degrees immediately after operation, but the loss of correction of kyphotic angle was 2.2 degrees after 3 months and 2.6 degrees after 6 months. We found that the loss of correction of kyphotic deformity occurred mainly within the first 3 months after surgery. Only one patient, suffered from acute hepatic failure after first operation and had an insufficient anti-tuberculous medication therapy, showed recurrence of tuberculous spondylitis after 6 months. The patient underwent a second operation with posterior fixation procedure with good outcome. The changes of ESR and CRP were not specifically important factor to reveal recurrence of tuberculosis of the spine in our series. CONCLUSION: The surgical procedure of tuberculous spondylitis using titanium mesh cage with bone chip seems to be an effective procedure to minimize loss of the correction of kyphotic deformity without any aggravating inflammatory change and recurrence with titanium mesh cage, when sufficient debridement and anti-tuberculous chemotherapy are achieved.

The results of the Posterior Lumbar Interboby Fusion using Titanium mesh cage for Spondylolisthesis / 대한척추외과학회지

STUDY DESIGN: This is a retrospective study analysing and comparing what between posterior lumbar interbody fusion plus posterior lateral fusion(PLIF+PLF) and PLF alone for Spondylolisthesis(Degenerative type+Isthmic type). Thirty patients were treated by posterior lumbar interbody fusion(PLIF) using Harms' cage and posterolateral fusion(PLF) with transpedicular screw fixation. Forty-nine patients were treated by posterolateral fusion with transpedicular screw fixation. OBJECTIVES: This is to verify the advantages of adding posterior lumbar interbody fusion using Harms' cage to the usual posterolateral fusion with transpedicular screw fixation SUMMARY OF BACKGROUND DATA: Interbody fusions have certain distinct mechanical advantages over posterolateral ones. Autologous cancellous bone is the preferred graft material, but might be soft to maintain the disc space during fusion. METHODS: Union rate, slip reduction, sagittal angle correction, disc height restoration, and clinical results by Lin's criteria were analysed. RESULTS: Nonunion was observed in 5 PLF cases(10%) and one PLIF case(3%). Loss of slip reduction was 0.7% in PLIF and 2.59% in PLF(P<0.05). Loss of sagittal angle correction was 1.27degreein PLIF and 3.65degreein PLF(P<0.05). Loss of disc height restoration was 2.6% in PLIF and 7.6% in PLF(P<0.05). Clinical evaluation in PLIF+PLF was excellent in 67%, good in 30%, and fair in 3%. Clinical evaluation in PLF was excellent in 59%, good in 33%, and fair in 8%. More excellent results were noted in PLIF+PLFcases. CONCLUSIONS: Adding posterior lumbar interbody fusion using Harms' cage showed better radiological results and more excellent clinical results compared to posterolateral fusion with transpedicular screw fixation.