Surgical Impacts of Metastatic Non-small Cell Lung Cancer to the Thoracic and Lumbar Spine

BackgroundSurgery for spinal metastasis is rapidly increasing in frequency with procedures ranging from laminectomy to spondylectomy combined with stabilization. This study investigated the effect of various surgical procedures for spinal metastasis of non-small cell lung cancer (NSCLC).MethodsA single-center consecutive series of patients who underwent surgery for spinal metastasis of NSCLC were retrospectively reviewed. Patients'' characteristics, radiographic parameters, operative data, clinical outcomes, and complications were analyzed. Surgical outcomes were assessed according to pain and performance status before and after surgery. Overall survival (OS) rate was estimated using the Kaplan-Meier method. Multivariate analysis was performed to detect factors independently associated with OS using a Cox proportional hazards model.ResultsTwenty-one patients were treated with laminectomy, 24 with corpectomy, 13 with spondylectomy (piecemeal or total en bloc fashion), and all procedures were combined with stabilization. Back pain and performance status improved significantly after surgical treatment among the three groups. Revision surgery due to tumor progression at the index level or spinal metastasis at another level were four patients (19.0%) in the laminectomy group, six patients (25.0%) in the corpectomy group, and one patient (7.7%) in the spondylectomy group. A Charlson comorbidity index and the number of spinal metastasis negatively affected OS (hazard ratio [HR], 19.613 and 2.244). Postoperative chemotherapy, time to metastasis, spondylectomy, and corpectomy had favorable associations with OS (HR, 0.455, 0.487, 0.619, and 0.715, respectively).ConclusionPostoperative chemotherapy was the most critical factor in OS of patients with metastatic NSCLC to the spine. An extensive surgical procedure (corpectomy/spondylectomy) with stabilization also could be beneficial for limited patients with spinal metastasis of NSCLC.     

Complications associated with cervical vertebral body replacement with expandable titanium cages

Our aim was to analyze complications and risk factors for cervical vertebral body replacement (VBR) with expandable titanium cages (ETC). Fifty patients; 22 women and 28 men, mean age 61 years, undergoing cervical VBR from 2010 to 2015 were analyzed. Complications were stratified by hardware-association (HA). Univariate and multivariate logistic regression was used to identify independent risk factors. Single, two and three level corpectomies were performed in 32, 15 and 3 patients respectively. A circumferential approach was necessary in 16 cases. At mean follow-up (7.3 months) 66% of patients had recovered. Radiological data showed a significant distraction (2.60 mm, p < 0.0001) and lordosis (5°, p = 0.001). Twenty-three patients experienced 42 complications; 18 HA, 24 non-HA and 24% needed revision surgery. The number of corpectomy levels and surgical approach significantly correlated with the risk of complications (p = 0.001), especially non-HA complications (p = 0.002). On multivariate analysis, only the number of corpectomy levels (p < 0.02, odds ratio 5.48, 95% CI 1.31–22.91) was a significant predictor of complications. We conclude that ETC are efficacious devices for cervical spine VBR, however, when used for more than 1 level, the corpectomy complication rate significantly increases.     

Three-Dimensional Endoscopy-Assisted Excision and Reconstruction for Metastatic Disease of the Dorsal and Lumbar Spine: Early Results

BackgroundThe aim of this study was to explore the role of three-dimensional (3D) endoscopy in surgical management of metastatic disease of the dorsal and lumbar spine.MethodsThis is a prospective study on 33 patients (15 men and 18 women, mean age of 61.6 ± 8.9 years) with biopsy-proven metastatic disease of the spine managed by sequential/staged posterior decompression-stabilization, followed by 3D endoscopy-assisted anterior corpectomy and stabilization with a mesh cage. All patients had significant extradural compression or spinal instability or both. Sixteen patients had neurological deficits. Visual analog scale (VAS), Frenkel grade (neurological deficits), Karnofsky performance status scale, and the 36-item short-form health survey (SF-36) were used for assessment preoperatively and at 3, 6, and 12 months from surgery.ResultsAt a mean follow-up of 1.7 ± 0.7 years from surgery, 18 patients were alive. VAS showed significant improvement at the latest follow-up compared to preoperative levels (4.39 vs. 6.61, p = 0.001). Karnofsky status did not show any significant improvement. Frenkel grade improved in 5 patients, deteriorated in 4 patients, and remained unchanged in 24 patients. Regarding SF-36 parameters, general health showed deterioration, but role functioning—physical, role functioning—emotional, social functioning, and body pain showed statistically significant improvement. There was no change in physical health, viability, and mental health. Subjectively the surgeons felt better depth perception and smoother surgical experience with the 3D optics technology. The only complication was delayed wound healing in three patients who had a previous history of radiotherapy to the surgical site.Conclusions3D endoscopy is a valuable tool in the management of metastatic spinal disease requiring excision and reconstruction using the combined posterior and anterior approaches. These early results warrant confirmation with more data and longer follow-ups.     

Surgical results of anterior corpectomy in the aged patients with cervical myelopathy

Retrospective study on the results of anterior corpectomy for the treatment of cervical myelopathy in patients over 70 years old. To evaluate the surgical results of anterior corpectomy in aged patients with multilevel cervical myelopathy and to investigate the probable pathomechanism by radiographic study. There are few data focused on the surgical results and post-operative complications of anterior corpectomy in aged patients with cervical myelopathy. Twenty patients 70 years of age or older who underwent anterior corpectomy, titanium mesh cage (TMC) reconstruction and anterior plate fixation for the treatment of compressive cervical myelopathy were reviewed. The average age at the time of operation was 75 years. Neurologic deficits before and after surgery were assessed using a scoring system proposed by the Japanese Orthopedic Association (JOA Score). Clinical results and post-operative complications were compared with those of patients 69 years old or younger as a control. Pre-operative Radiologic evaluation of every patient consisted of anterior–posterior, lateral, bilateral oblique, flextion, and extension radiographs, computed tomography and magnetic resonance imaging of the cervical spine. Any factor causing spinal cord compression and the sign of cervical instability were recorded. Surgical-related complications occurred in seven patients in the aged group. The incidence of complications was 35% in the aged patient group and 9.7% in the control group respectively. Although the difference was striking, no statistical significance was found between the two groups. One patient died of respiratory failure resulting from pulmonary infection. The mortality rate was 5%. The pre-operative mean JOA score was 9.3 (from 3 to 14) in the aged patient group. Nineteen patients were followed at least 2 years and the mean JOA score was 13.4 (from 8 to 17). 68.4% of the aged patients achieved a good or excellent result. There was no statistical difference in the recovery rate of JOA score between the aged group (58.1%) and control group (67.0%). In the pre-operative radiographs, the incidence of cervical instability was much higher in the control group (32%) than in the aged group (5%) and multilevel cord compression caused by posterior disc space osteophytes was more common in the aged group. Anterior corpectomy combined with TMC fusion and plate fixation provides favorable neurologic recovery even in the patients over 70 years old. However, the incidence of surgical related complications shows a conspicuous increasing in the aged patients. Overcompensation mechanism for cervical instability is the probable cause of degenerative cervical spondylotic myelopathy in aged patients.     

Tantalum trabecular metal implants in anterior cervical corpectomy and fusion: 2-year prospective analysis

Anterior cervical decompression for two or more cervical spondylotic levels can be performed using either multiple anterior cervical discectomies and fusion or anterior cervical corpectomy and fusion (ACCF). A variety of options for ACCF implants exist but to our knowledge, there is no clinical data for the use of tantalum trabecular metal implants (TTMI) for ACCF. A retrospective review was performed of prospectively collected data for ten patients undergoing ACCF with TTMI between 2011 and 2012. Radiological outcome was assessed by measuring the change in cervical (C) lordosis (fusion Cobb and C2–C7 Cobb), graft subsidence (anterior/posterior, determined by the subsidence of anterior/posterior body height of fused segments; cranial/caudal, determined by the cranial/caudal plate-to-disc distances) and rate of fusion using lateral cervical X-rays of patients at 0, 6, 12 and 24 months post-operatively. The Neck Disability Index (NDI) assessed clinical outcome pre-operatively and at 6, 12 and 24 months post-operatively. Cervical lordosis (Cobb angle of fused segment) was 5.2° (± 4.2°) at 0 months and 6.0° (± 5.7°) at 24 months post-operatively. Graft subsidence was observed to occur at 6 months post-operatively and continued throughout follow-up. Anterior, posterior and caudal subsidence occurred more in the first 12 months post-operatively than in the following 12 months (p < 0.05). Average pre-operative NDI was 45%. Average NDIs were 18%, 13% and 10% at 6, 12 and 24 months post-operatively, respectively. ACCF patients treated with TTMI demonstrated stable cervical lordosis over 2 years of follow-up and 100% fusion rates after 2 years. Measures of subsidence appeared to decrease with time. Patients experienced improved clinical outcomes over the 2-year period.     

The stabilizing potential of anterior, posterior and combined techniques for the reconstruction of a 2-level cervical corpectomy model: biomechanical study and first results of ATPS prototyping

Clinical studies reported frequent failure with anterior instrumented multilevel cervical corpectomies. Hence, posterior augmentation was recommended but necessitates a second approach. Thus, an author group evaluated the feasibility, pull-out characteristics, and accuracy of anterior transpedicular screw (ATPS) fixation. Although first success with clinical application of ATPS has already been reported, no data exist on biomechanical characteristics of an ATPS-plate system enabling transpedicular end-level fixation in advanced instabilities. Therefore, we evaluated biomechanical qualities of an ATPS prototype C4–C7 for reduction of range of motion (ROM) and primary stability in a non-destructive setup among five constructs: anterior plate, posterior all-lateral mass screw construct, posterior construct with lateral mass screws C5 + C6 and end-level fixation using pedicle screws unilaterally or bilaterally, and a 360° construct. 12 human spines C3–T1 were divided into two groups. Four constructs were tested in group 1 and three in group 2; the ATPS prototypes were tested in both groups. Specimens were subjected to flexibility test in a spine motion tester at intact state and after 2-level corpectomy C5–C6 with subsequent reconstruction using a distractable cage and one of the osteosynthesis mentioned above. ROM in flexion–extension, axial rotation, and lateral bending was reported as normalized values. All instrumentations but the anterior plate showed significant reduction of ROM for all directions compared to the intact state. The 360° construct outperformed all others in terms of reducing ROM. While there were no significant differences between the 360° and posterior constructs in flexion–extension and lateral bending, the 360° constructs were significantly more stable in axial rotation. Concerning primary stability of ATPS prototypes, there were no significant differences compared to posterior-only constructs in flexion–extension and axial rotation. The 360° construct showed significant differences to the ATPS prototypes in flexion–extension, while no significant differences existed in axial rotation. But in lateral bending, the ATPS prototype and the anterior plate performed significantly worse than the posterior constructs. ATPS was shown to confer increased primary stability compared to the anterior plate in flexion–extension and axial rotation with the latter yielding significance. We showed that primary stability after 2-level corpectomy reconstruction using ATPS prototypes compared favorably to posterior systems and superior to anterior plates. From the biomechanical point, the 360° instrumentation was shown the most efficient for reconstruction of 2-level corpectomies. Further studies will elucidate whether fatigue testing will enhance the benefit of transpedicular anchorage with posterior constructs and ATPS.     

Comparison of ventral corpectomy and plate-screw-instrumented fusion with dorsal laminectomy and rod-screw-instrumented fusion for treatment of at least two vertebral-level spondylotic cervical myelopathy

The objective of the article is to verify the hypothesis that the dorsal multilevel laminectomy and rod-screw-instrumented fusion (DLF) for multilevel spondylotic cervical myelopathy (MSCM) is less strenuous for patients, and less prone to perioperative complications, than ventral multilevel corpectomy and plate-screw-instrumented fusion (VCF), while clinical outcome is comparable. One hundred and three successive patients were treated for at least two vertebral-level MSCM, 42 of them by VCF and 61 by DLF. The two patients groups were retrospectively compared. VCF patients were slightly younger than DLF patients (62.5 ± 10.61 years versus 66 ± 12.4 years, P = 0.012). In VCF patients, a median of 2 (2–3) corpectomies and in DLF patients a median of 3 (2–5) laminectomies were performed. In VCF patients, surgery lasted longer than in DLF patients (229 ± 60 min versus 183 ± 46 min, P ≤ 0.001). Between the VCF and the DLF patients groups, no significant difference was found in perioperative complications (e.g. hardware failure rates of 16.7% in VCF and of 6.6% in the DLF patients) and mortality rates. The postoperative outcome, as assessed by the postoperative change of the Nurick scores, the change of neck pain, the patients’ satisfaction, and the change of the subaxial Cobb angle of the spine did not differ between the two patients groups. However, when comparing the postoperative Nurick scores directly, VCF patients fared somewhat better than DLF patients [median of 2 (0–5) versus 3 (1–5), P = 0.003]. The hypothesized advantages of DLF over VCF in the surgical treatment of at least two vertebral-level MSCM could not be confirmed in this retrospective study. A prospective randomized study is warranted to clarify this issue.     

有、无垫片钛网植骨对终板-钛网界面应力分布影响的比较

目的 比较有、无垫片钛网植骨对颈椎前路椎体次全切除减压终板-钛网界面应力分布的影响.方法 利用Ansys 9.0软件的建模功能,建立有、无垫片钛网植骨钢板固定手术模型.分别对模型施加80 N预载荷及1.8 Nm力矩,使其产生轴向压缩、前屈和后伸运动,选取终板.钛网界面7个接触点,提取各个点的von Mises应力,然后进行比较.结果 在各种工况下,有垫片钛网植骨C4下终板-钛网界面(5.43、5.74、6.88)Mpa和C6上终板-钛网界面7个各个接触点的应力(7.61、8.23、9.97)Mpa分别小于无垫片钛网植骨C4下终板-钛网界面(7.46、8.12、10.04)Mpa和C6上终板-钛网界面相应接触点的应力(10.65、11.59、14.27)Mpa.结论 有垫片钛网植骨能够降低终板-钛网界面的应力,避免终板应力的过度集中,从而降低钛网下沉的发生率.     

A comparison of anterior cervical discectomy and corpectomy in patients with multilevel cervical spondylotic myelopathy

Background  

The optimal surgical approach for multilevel cervical spondylotic myelopathy (CSM) has not been defined, and the relative merits of multilevel anterior cervical discectomy and fusion (ACDF) and anterior cervical corpectomy (2-level or skip 1-level corpectomy) and fusion (ACCF) remain controversial. However, few comparative studies have been conducted on these two surgical approaches.