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Background: Currently, in the specialized literature there are no substantiated clinical and radiological indications for differentiated use of anterior cervical discectomy and fusion (ACDF) and anterior cervical corpectomy and fusion (ACCF) in the treatment of patients with two-segmental cervical degenerative diseases. The objectives of this study were to (I) identify risk factors that were associated with unsatisfactory results of two-level ACDF and one-level ACCF in the treatment of patients with cervical degenerative diseases despite current perioperative management, and (II) develop a clinical and radiological algorithm for personalized surgical tactics. Methods: We retrospectively identified risk factors for the development of unsatisfactory clinical postoperative results after two-level ACDF (n=81) and one-level ACCF (n=78), operated in the period of 2009-2019 for two-segmental cervical degenerative disease. Results: Satisfactory clinical results after two-level ACDF were noted in cases with total kyphotic deformity of less than 15°; local kyphotic deformity less than 10Ë; the absence of circumferential spondylotic cervical stenosis; the absence of a myelopathic lesion at the level of the vertebral body; absence of migrating intervertebral disk (IVD) hernia more than 1/3 of the vertebral body; T1 slope vertebra less than 15°; IVD degeneration according to Suzuki A. 0-II; facet joint (FJ) degeneration according to Okamoto A. I-III; interbody height (IH) more than 2 mm. Satisfactory clinical results after single-level ACCF were registered in cases with IVD degeneration according to Suzuki A. III; FJ degeneration according to Okamoto A. IV-V; IH 3 mm or less; regardless of the cervical lordosis, the angle of local kyphotic deformity and T1 slope, the presence of circumferential spondylotic cervical stenosis, the localization of the myelopathic lesion and the distance of migration IVD herniation. Conclusions: Individual planning and differentiated implementation of ACDF and ACCF in patients with two-segmental cervical degenerative disease, taking into account a comprehensive preoperative clinical and radiological assessment, contributes to the effective elimination of existing neurological symptoms, reducing the intensity of neck pain and upper limbs pain, restoring the functional state and quality of patients' lives in the minimum 24 months postoperative period, as well as reducing the number of postoperative complications and reoperations.
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BACKGROUND: Cervical spondylotic myelopathy (CSM) is a common cause of neurological morbidity, which can have an impact on quality of life. Symptomatic postoperative spinal epidural hematoma (SPSEH) is a rare condition, but can cause permanent neurological deficits and disability if not managed properly. However, there are limited studies on the outcomes of SPSEH after anterior cervical discectomy and fusion (ACDF) and anterior cervical corpectomy and fusion (ACCF) were performed for 2-level CSM. Therefore, the aim of the present study was to compare the clinical outcomes and incidence of SPSEH after ACDF compared with SPSEH after anterior cervical corpectomy and ACCF for 2-level CSM to reduce surgical complications of 2 level CSM. METHODS: A total of 551 patients (261 males and 290 females) who underwent ACDF or ACCF for 2-level CSM from January 2009 to February 2015 were retrospectively reviewed. Preoperative indexes (age, sex, body mass index, bone mineral density, preoperative coagulation, and past medical history), perioperative indexes (length of hospital admission, blood loss, and operation times), preoperative and postoperative neurological statuses, complications, fusion rate, and the SPSEH incidence for ACDF or ACCF were compared simultaneously. RESULTS: With the exception of blood loss (P<0.001), no significant differences were observed between the 2 groups in terms of sex, prothrombin time, activated partial thromboplastin time, platelet count, length of hospital admission, operation time, the final follow-up Japanese Orthopedic Association score, visual analog scale score, fusion rate, and complications. The overall incidence rate for SPSEH after ACDF was 1.9%, while the rate for SPSEH after ACCF was 0.4%. Following hematoma removal, only one patient showed any improvement in neurological function, despite treatment with hyperbaric oxygen and neurotrophic drugs. CONCLUSIONS: The findings indicated that surgical management of 2-level CSM using ACDF or ACCF showed similar clinical outcomes, fusion rate, complications, and perioperative parameters, with the exception of blood loss. However, SPSEH preferentially occurs after surgery with ACDF. Therefore, whether ACCF surgery for 2-stage CSM is the superior treatment modality.
Subject(s)
Hematoma, Epidural, Spinal , Spinal Cord Diseases , Spinal Fusion , Spondylosis , Diskectomy/adverse effects , Female , Hematoma, Epidural, Spinal/complications , Hematoma, Epidural, Spinal/surgery , Humans , Male , Quality of Life , Retrospective Studies , Spinal Cord Diseases/complications , Spinal Cord Diseases/surgery , Spinal Fusion/adverse effects , Spondylosis/complications , Spondylosis/surgery , Treatment OutcomeABSTRACT
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.
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BACKGROUND: This was a prospective randomized cohort study aiming at examining the safety and efficacy of artificial vertebral body (AVB) fabricated by electron beam melting (EBM) in comparison to conventional titanium mesh cage (TMC) used in single-level anterior cervical corpectomy and fusion (SL-ACCF). METHODS: Forty patients with cervical spondylotic myelopathy (CSM) underwent SL-ACCF using either the EBM-AVB or the TMC. Patients were evaluated for their demographics, radiological characteristics, neurologic function [using the Japanese Orthopaedic Association (JOA) scale], and health-related quality-of-life (HRQoL) aspects [using the Short Form 36 (SF-36)] before and after the surgery and comparison was made between the two groups both at baseline and the last follow-up. The Student t-text, paired-sample t-text, and Fisher's exact test were used when appropriate to detect any statistical significance at the level of α=0.05. RESULTS: Post-operative recovery was uneventful for all patients and no revision surgery was required. There were no significant differences between the EBM-AVB group and the TMC group at baseline. Patients in both groups demonstrated significant improvement in cervical alignment, JOA score, and SF-36 score after the surgery. Six months post-operatively, patients in the EBM-AVB group were found to have significantly less loss of fusion height and lower incidence for severe implant subsidence compared with the TMC group. Patients in the two groups were comparable at the last follow-up regarding their rate of fusion, cervical alignment, JOA recovery rate, SF-36 score, and by Odom's criteria. CONCLUSIONS: For CSM patients undergoing SL-ACCF, the EBM-AVB group demonstrated comparable outcomes regarding patient cervical alignment, neurologic function, and HRQoL in comparison with the TMC group. Furthermore, the use of EBM-AVB was associated with decreased loss of the height of the fusion mass and a lower rate for severe implant subsidence.
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OBJECTIVE: To introduce anterior controllable antedisplacement fusion (ACAF), a new surgical technique, to treat multilevel cervical spondylotic myelopathy with spinal stenosis and compare ACAF with anterior cervical corpectomy and fusion (ACCF). METHODS: Patients with multilevel cervical spondylotic myelopathy with spinal stenosis who underwent ACAF (36 cases) and ACCF (45 cases) from January 2016 to June 2017 were enrolled in this study. Japanese Orthopaedic Association score was analyzed before the operation and at each scheduled follow-up during the follow-up period after surgery to evaluate neurologic function. Clinical and radiologic outcomes and perioperative complications were analyzed. RESULTS: At the final follow-up, mean Japanese Orthopaedic Association scores of the 2 groups were significantly improved compared with preoperatively (P < 0.01 and P < 0.01). However, mean Japanese Orthopaedic Association scores between the 2 groups were not statistically significant (13.7 ± 1.9 vs. 13.5 ± 1.8, P = 0.66). Operative duration was longer and blood loss was greater in the ACAF group compared with the ACCF group. Overall occurrence of complications in the ACAF group was significantly lower compared with the ACCF group (P < 0.05). CONCLUSIONS: ACAF has similar clinical and radiologic outcomes and fewer complications compared with ACCF in treatment of multilevel cervical spondylotic myelopathy with spinal stenosis. ACAF can be used as an alternative treatment for cervical stenosis.
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OBJECTIVE: Anterior cervical corpectomy and fusion (ACCF), in which a ventral constriction is resected, can decompress myelopathy and is considered the optimal treatment for ossification of the posterior longitudinal ligament (OPLL) up to now. However, its disadvantages are incomplete decompression, high surgery- and implant-related complication rates, and extremely surgical technique demanding. Our object was to introduce anterior controllable antedisplacement fusion (ACAF), a new surgical technique to treat OPLL, and compare it with ACCF. METHODS: ACAF was performed on 34 patients with spinal stenosis with myelopathy due to severe (occupying rate ≥50%) OPLL. Pre- and postoperatively, we measured decompression width and spinal canal area on cross-sectional computed tomography and morphology and anteroposterior diameter of the spinal cord at the most severely affected segment on cross-sectional magnetic resonance imaging and cross-sectional computed tomography. Japanese Orthopedic Association scoring was used to evaluate neurologic status. The ACAF group and a control group of 36 patients with ACCF were compared. RESULTS: Postoperatively, decompression width (17.9 ± 1.0 vs. 15.1 ± 0.8 mm; P < 0.01), spinal canal area (150.4 ± 31.6 vs. 127.0 ± 27.0 mm2; P < 0.01), and anteroposterior spinal cord diameter (5.4 ± 0.6 vs. 5.0 ± 1.1 mm; P < 0.05) were significantly greater in the ACAF group. At 6 months, mean Japanese Orthopedic Association score was significantly better in the ACAF group (15.4 ± 0.9 vs. 14.5 ± 2.5 points; P = 0.04). CONCLUSIONS: ACAF, providing adequate decompression of the spinal cord and good outcomes, is a well choice in the treatment of spinal stenosis due to severe OPLL.
Subject(s)
Cervical Vertebrae/surgery , Decompression, Surgical , Longitudinal Ligaments/surgery , Ossification of Posterior Longitudinal Ligament/surgery , Spinal Stenosis/surgery , Adult , Aged , Cross-Sectional Studies , Decompression, Surgical/methods , Female , Humans , Male , Middle Aged , Osteogenesis/physiology , Retrospective Studies , Spinal Cord Diseases/surgery , Treatment OutcomeABSTRACT
Age-related degenerative changes and non-spondylotic pathologies of the cervical spine such as trauma and tumor can lead to compression of neurological structures and result in substantial alteration of the structural anatomy. The end-goal of surgical intervention is to decompress the neural structures which can be achieved via an anterior or a posterior approach, and stabilization of segments to restore stability and alignment. Three-dimensional printing (3DP or Additive Manufacturing) has been applied to the field of medicine, in particular orthopedics and neurosurgery. Coupled with advances of medical imaging such as computed tomography (CT) scans and magnetic resonance imaging (MRI), accurate 3D models of patient anatomy can be produced, and patient-specific implants (PSIs) for complex anatomical reconstruction have all been applied with positive outcomes. 3D printed implants have been applied in particular to the cervical spine predominantly due to the complex and relatively small osteological anatomy and the proximity of important neurovascular structures to the surgical sites. The purpose of this review is to evaluate the current application of 3DP for cervical spinal implants. This includes a review on the available literature on 3D printed PSIs and current available 3D printed "off-the-shelf" (OTS) implants (3D-OTS). Suitable materials for 3DP of spinal implants and the future prospect of cervical implants will be discussed. The review will be concluded with a suggested guide for carrying future studies to evaluate the efficacy and safety of 3DP for cervical spinal implants.
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Objective To establish the three-dimensional finite element model of human lower cervical spine C3-7 motion segments after anterior cervical corpectomy and fusion (ACCF) surgery with titanium mesh and bone graft, and to analyze the stability of cervical spine and stress distribution of internal fixation devices after ACCF surgery. Methods The finite element model of cervical spine C3-7 segments after ACCF of C5 segment with titanium mesh, bone graft, plate and screw fixation was established，and C3-7 segment intact model of cervical vertebra was also constructed. The torque moment of 0.5, 1.0, 1.5, 2.0 N﹒m was applied to the ACCF surgery model. The ROM, maximum stress in facet joint and stress distributions on internal fixation devices under flexion, extension, lateral bending and torsion movement were analyzed. Results ROM of reconstructed C5 segment increased with the torque moment increasing after ACCF surgery. In the case of 1.0 N﹒m torque moment and 50 N preload, the ROM of reconstructed C5, C3-4, C6-7 and C3-7 segment was reduced by 81%, 62%, 58% and 80% compared with the intact model. The maximum stress in facet joint of reconstructed C5 segment reduced and the stress in adjacent segments significantly increased. The stress of titanium mesh was mainly distributed on the compression side of movement, and high stress was located in the roots of screws. Conclusions ACCF surgery can promote the stability of cervical spine, decrease the stress in facet joint of operation segment, and has better treatment effect on easing compression from spinal cord caused by cervical spondylotic myelopathy. The research results will provide some theoretical basis for clinical application of ACCF.
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Objective To establish the three-dimensional finite element model of human lower cervical spine C3-7 motion segments after anterior cervical corpectomy and fusion (ACCF) surgery with titanium mesh and bone graft,and to analyze the stability of cervical spine and stress distribution of internal fixation devices after ACCF surgery.Methods The finite element model of cervical spine C3-7 segments after ACCF of C5 segment with titanium mesh,bone graft,plate and screw fixation was established,and C3-7 segment intact model of cervical vertebra was also constructed.The torque moment of 0.5,1.0,1.5,2.0 N · m was applied to the ACCF surgery model.The ROM,maximum stress in facet joint and stress distributions on internal fixation devices under flexion,extension,lateral bending and axial rotation movement were analyzed.Results ROM of reconstructed C5 segment increased with the torque moment increasing after ACCF surgery.In the case of 1.0 N · m tomue moment and 50 N preload,the ROM of reconstructed C5,C3-4,C6-7 and C3-7 segment was reduced by 81％,62％,58％ and 80％ compared with the intact model.The maximum stress in facet joint of reconstructed C5 segment reduced and the stress in adjacent segments significantly increased.The stress of titanium mesh was mainly distributed on the compression side of movement,and high stress was located in the roots of screws.Conclusions ACCF surgery can promote the stability of cewical spine,decrease the stress in facet joint of operation segment,and has better treatment effect on easing compression from spinal cord caused by cervical spondylotic myelopathy.The research results will provide some theoretical basis for clinical application of ACCF surgery.
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Objective To establish the three-dimensional finite element model of human lower cervical spine C3-7 motion segments after anterior cervical corpectomy and fusion (ACCF) surgery with titanium mesh and bone graft,and to analyze the stability of cervical spine and stress distribution of internal fixation devices after ACCF surgery.Methods The finite element model of cervical spine C3-7 segments after ACCF of C5 segment with titanium mesh,bone graft,plate and screw fixation was established,and C3-7 segment intact model of cervical vertebra was also constructed.The torque moment of 0.5,1.0,1.5,2.0 N · m was applied to the ACCF surgery model.The ROM,maximum stress in facet joint and stress distributions on internal fixation devices under flexion,extension,lateral bending and axial rotation movement were analyzed.Results ROM of reconstructed C5 segment increased with the torque moment increasing after ACCF surgery.In the case of 1.0 N · m tomue moment and 50 N preload,the ROM of reconstructed C5,C3-4,C6-7 and C3-7 segment was reduced by 81％,62％,58％ and 80％ compared with the intact model.The maximum stress in facet joint of reconstructed C5 segment reduced and the stress in adjacent segments significantly increased.The stress of titanium mesh was mainly distributed on the compression side of movement,and high stress was located in the roots of screws.Conclusions ACCF surgery can promote the stability of cewical spine,decrease the stress in facet joint of operation segment,and has better treatment effect on easing compression from spinal cord caused by cervical spondylotic myelopathy.The research results will provide some theoretical basis for clinical application of ACCF surgery.
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Objective To establish the three-dimensional finite element model of human lower cervical spine C3-7 motion segments after anterior cervical corpectomy and fusion (ACCF) surgery with titanium mesh and bone graft,and to analyze the stability of cervical spine and stress distribution of internal fixation devices after ACCF surgery.Methods The finite element model of cervical spine C3-7 segments after ACCF of C5 segment with titanium mesh,bone graft,plate and screw fixation was established,and C3-7 segment intact model of cervical vertebra was also constructed.The torque moment of 0.5,1.0,1.5,2.0 N · m was applied to the ACCF surgery model.The ROM,maximum stress in facet joint and stress distributions on internal fixation devices under flexion,extension,lateral bending and axial rotation movement were analyzed.Results ROM of reconstructed C5 segment increased with the torque moment increasing after ACCF surgery.In the case of 1.0 N · m tomue moment and 50 N preload,the ROM of reconstructed C5,C3-4,C6-7 and C3-7 segment was reduced by 81％,62％,58％ and 80％ compared with the intact model.The maximum stress in facet joint of reconstructed C5 segment reduced and the stress in adjacent segments significantly increased.The stress of titanium mesh was mainly distributed on the compression side of movement,and high stress was located in the roots of screws.Conclusions ACCF surgery can promote the stability of cewical spine,decrease the stress in facet joint of operation segment,and has better treatment effect on easing compression from spinal cord caused by cervical spondylotic myelopathy.The research results will provide some theoretical basis for clinical application of ACCF surgery.
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BACKGROUND: Common fusion techniques for cervical degenerative diseases include two-level anterior discectomy and fusion and one-level corpectomy and fusion. The aim of the study was to compare via in-vitro biomechanical testing the effects of a two-level anterior discectomy and fusion and a one-level corpectomy and fusion, with anterior plate reconstruction. METHODS: Seven fresh frozen human cadaveric spines (C3-T1) were dissected from posterior musculature, preserving the integrity of ligaments and intervertebral discs. Initial biomechanical testing consisted of no-axial preload and 2Nm in flexion-extension, lateral bending and axial rotation. Thereafter, discectomies were performed at C4-5 and C5-6 levels, then two interbody cages and an anterior C4-C5-C6 plate was implanted. The flexibility tests were repeated and followed by C5 corpectomy and C4-C6 plate reconstruction. Biomechanical testing was performed again and statistical comparisons among the means of range of motion and axial rotation energy loss were investigated. FINDINGS: The two-level cage-plate construct had significantly lower range of motion than the one-level corpectomy-plate construct (P≤0.03). Axial rotation energy loss was significantly (P≤0.03) greater for the corpectomy-plate construct than for the two-level cage-plate construct and the intact condition. INTERPRETATION: A two-level cage-plate construct provides greater stability in flexion, extension and lateral bending motions when compared to a one-level corpectomy-plate construct. A two-level cage-plate is more likely to maintain axial balance by reducing the energy lost in axial rotation.
