Corpectomy For Cervical Spondylotic Myelopathy Research Articles

Risk Factors and Radiologic Changes in Subsidence after Single-Level Anterior Cervical Corpectomy: A Minimum Follow-Up of 2 Years.

ObjectiveAnterior cervical corpectomy using a titanium mesh cage may result in delayed nonunion and thus a change in cervical alignment, and patients may require revision surgery. We investigated the radiologic and clinical outcomes of cervical corpectomy and the risk factors for subsidence.MethodsWe studied 74 patients who underwent single-level anterior cervical corpectomy for cervical spondylotic myelopathy with or without ossification of the posterior longitudinal ligament between 2007 and 2014. Graft subsidence was considered present when there was a reduction in the anterior and posterior heights by an average of 4 mm or more 2 years after the operation. We measured cervical parameters before surgery, immediately after surgery, and 6, 12, and 24 months after surgery. The clinical outcomes were the neck and arm visual analog scale scores and reoperation rate.ResultsIn the subsidence group, these values gradually decreased over the 24 months. The radiologic parameters did not differ between the 2 groups for 24 months after the onset of subsidence. There were no differences in clinical outcome or reoperation rate. In the analysis of the risk factors, subsidence occurred with a large T1 slope and a large change in the C27 Cobb angle (p=0.020 and p=0.026, respectively).ConclusionSubsidence gradually occurred after single-level anterior cervical corpectomy for up to 24 months. However, the presence of subsidence did not affect the radiologic and clinical outcomes. When the T1 slope was large and the C27 Cobb angle change was severe, more subsidence occurred.

A prospective randomized cohort study on 3D-printed artificial vertebral body in single-level anterior cervical corpectomy for cervical spondylotic myelopathy.

BackgroundThis 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).MethodsForty 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.ResultsPost-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.ConclusionsFor 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.

Surgical Reconstruction Using a Flanged Mesh Cage without Plating for Cervical Spondylotic Myelopathy and a Symptomatic Ossified Posterior Longitudinal Ligament.

ObjectiveWe introduce innovative method of cervical column reconstruction and performed the reconstruction with a flanged titanium mesh cage (TMC) instead of a plate after anterior corpectomy for cervical spondylotic myelopathy (CSM) and an ossified posterior longitudinal ligament (OPLL). MethodsFifty patients with CSM or OPLL who underwent anterior cervical reconstruction with a flanged TMC were investigated retrospectively. Odom’s criteria were used to assess the clinical outcomes. The radiographic evaluation included TMC subsidence, fusion status, and interbody height. Thirty-eight patients underwent single-level and 12 patients underwent two-level corpectomy with a mean follow-up period of 16.8 months. ResultsIn all, 19 patients (38%) had excellent outcomes and 25 patients (50%) had good outcomes. Two patients (4%) in whom C5 palsy occurred were categorized as poor. The fusion rate at the last follow-up was 98%, and the severe subsidence rate was 34%. No differences in subsidence were observed among Odom’s criteria or between the single-level and two-level corpectomy groups. ConclusionThe satisfactory outcomes in this study indicate that the flanged TMC is an effective graft for cervical reconstruction.

Long-Term Sustainability of Functional Improvement Following Central Corpectomy for Cervical Spondylotic Myelopathy and Ossification of Posterior Longitudinal Ligament.

Retrospective study. To examine predictors of long-term outcome and sustainability of initial functional improvement in patients undergoing corpectomy for cervical spondylotic myelopathy (CSM) or ossification of the posterior longitudinal ligament (OPLL). There are limited data on the predictors of outcome and sustainability of initial functional improvement on long-term follow-up after cervical corpectomy. We studied the functional outcome at more than 1-year follow-up after central corpectomy in 352 patients with CSM or OPLL. Functional status was evaluated with the Nurick grading system. Analysis was directed at identifying factors associated with both improvement in functional status and the achievement of a "cure" (improvement to a follow-up Nurick grade of 0 or 1). A survival analysis was performed to identify factors associated with sustained functional improvement in patients with serial follow-up evaluations. Nurick grade improved from 3.2 ± 0.1 to 1.9 ± 0.1 over a mean follow-up period of 57.1 months (range 12-228 mo). On multivariate analysis, age ≥50 years (P = 0.008) and symptom duration ≥1 year (P < 0.001) were negatively associated with functional improvement by ≥1 Nurick grade. Independent factors negatively associated with "cure" after surgery included age 50 years or older (P = 0.005), preoperative Nurick grade of 4 or higher (P < 0.001) and symptom duration of 1 or more years (P < 0.001). Early improvement in functional status was maintained in 90.5% and 76.3% of patients at 5 and 10 years follow-up, respectively. On survival analysis, patients with shorter preoperative symptom duration (<1 yr) were more likely to demonstrate sustained improvement in functional status after surgery (P = 0.022). Initial gains in functional status after central corpectomy for CSM and OPLL are maintained in more than 75% of patients at 10 years after surgery. Overall, the most favorable long-term outcomes are achieved in younger patients who present early and with good preoperative functional status. 4.

Evaluation of hand function in healthy individuals and patients undergoing uninstrumented central corpectomy for cervical spondylotic myelopathy using nine-hole peg test.

To evaluate the hand function in healthy individuals and in patients with cervical spondylotic myelopathy (CSM) undergoing central corpectomy using the nine-hole peg test (NHPT). The NHPT was performed in healthy adults and in patients with CSM; overall, five trials were performed in the right and left hand separately. The preoperative and follow up NHPT score was compared to the normal and correlated with Nurick and modified Japanese Orthopedic Association (mJOA) scales. The NHPT score was significantly less in adult healthy female compared to adult healthy male subjects (difference, 0.71 s, P < 0.002). The distribution of the NHPT scores in normal adults followed the normal binomial distribution. The time taken to perform the NHPT with the right hand was significantly lower than the time taken to perform the NHPT with the left hand in both the sexes (P < 0.001). Thirty-six of the 47 patients with CSM (76.6%) had a prolonged preoperative NHPT score. There was a strong negative correlation between the preoperative NHPT score and the preoperative upper limb component of the modified-Japanese Orthopedic Association (UlmJOA) score. No significant change was detected in the NHPT score at one week postoperatively. On follow-up at six months or more (n = 21), the NHPT score normalized in five (35.7%) of the 14 patients in whom it was prolonged preoperatively. The NHPT score remained the same as the preoperative status in the other 16 patients, 7 of whom had a normal score preoperatively. The change in the NHPT score at follow-up did not correlate with the change in the UlmJOA score. Normative data among the Indian population suggest that female subjects have significantly lower scores than the male ones, and that there is a difference between the two sides that needs to be considered while reporting the NHPT scores in disease. The NHPT scores were prolonged preoperatively in CSM and showed a correlation with the UlmJOA score, and there was no significant change noted at one week follow-up. While the NHPT score is a good quantitative test to evaluate hand function in patients with CSM and could detect subtle hand dysfunction preoperatively, it has a limited role, when used alone, to detect changes in hand function postoperatively.

Clinical adjacent-segment pathology after central corpectomy for cervical spondylotic myelopathy: incidence and risk factors.

OBJECTIVE The goal of this study was to investigate the prevalence and risk factors of clinical adjacent-segment pathology (CASP) following central corpectomy for cervical spondylotic myelopathy (CSM) or ossification of the posterior longitudinal ligament (OPLL). METHODS The authors reviewed 353 cases involving patients operated on by a single surgeon with a minimum 12-month follow-up after central corpectomy for CSM or OPLL between 1995 and 2007. Patients with symptoms consistent with CASP at follow-up were selected for the study. The authors analyzed the prevalence and risk factors for CASP after central corpectomy for CSM/OPLL. RESULTS Fourteen patients (13 male, 1 female; mean age 46.9 ± 7.7 years) were diagnosed with symptoms of CASP (3.9% of 353 patients) at follow-up. The mean interval between the initial surgery and presentation with symptoms of CASP was 95.6 ± 54.1 months (range 40-213 months). Preoperative Nurick grades ranged from 2 to 5 (mean 3.5 ± 1.2), and the Nurick grades at follow-up ranged from 1 to 5 (mean 3.0 ± 1.3, p = 0.27). Twelve patients had myelopathic symptoms and 2 had radiculopathy at follow-up. Patients with poorer preoperative Nurick grades had a higher risk for development of CASP (HR 2.6 [95% CI 1.2-5.3], p = 0.01). CONCLUSIONS In the present study, CASP was seen in 3.9% of patients following central corpectomy for CSM/OPLL. The risk of CASP after central corpectomy for CSM/OPLL was higher in patients with poorer preoperative Nurick grades.

Remote Cervical Pseudomeningocele Following Anterior Cervical Corpectomy and Fusion: Report of a Case and Review of the Literature.

Iatrogenic cervical pseudomeningocele is a rare event and majority are located posteriorly as a delayed complication of inadvertent dural tear after decompressive laminectomy. However, iatrogenic anterior cervical pseudomeningocele subsequent to discectomy or corpectomy is a rare pathology. The time necessary for formation of pseudomeningocele varies and depend on the width of the dural tear and the flow of cerebrospinal fluid leakage. Large tears with high CSF flow usually result in early collection of the cerebrospinal fluid in anterior compartment of the neck designated acute pseudomeningoceles. Micro-tears of dura mater, with low flow of cerebrospinal fluid may lead to late formation of a pseudomeningocele known as chronic ones. Herein a 49- year-old woman in whom cervical pseudomeningocele appeared clinically as a mass on the anterior aspect of the neck, six months after anterior cervical corpectomy for cervical spondylotic myelopathy is presented. Otherwise, she was neurologically stable. Cystoperitoneal shunt was proposed which she refused. Surprisingly, at 2-year follow-up, the cyst had remained of the same size. To the best of our knowledge, this is the first example of post-operative chronic cervical pseudomeningocele in the literature, the event that might propose the self-limited natural course of this rare pathology in chronic cases.

Anterior cervical corpectomy for cervical spondylotic myelopathy: Reconstruction with expandable cylindrical cage versus iliac crest autograft. A retrospective study

ObjectivesTo compare retrospectively the clinical and radiographic outcomes between cervical reconstruction with expandable cylindrical cage (ECC) and iliac crest autograft after one- or two-level anterior cervical corpectomy for spondylotic myelopathy. Patients and methodsForty-two patients underwent cervical reconstruction with either iliac crest autograft and plating (20 patients) or ECC and plating (22 patients). The average clinical and radiological follow-up period was 77.54±44.28 months (range 14–155 months). The authors compared clinical parameters (Nurick Myelopathy Grade, modified Japanese Orthopedic Association (mJOA) scores), perioperative parameters (hospital stays, complications) and radiological parameters (Cobb's angles of the fused segments and C2–C7 segments, cervical subsidence, fusion rate). Fusion was assessed on flexion–extension X-ray films. ResultsNo significant differences between the two groups were found in demographics, neurological presentation, preoperative sagittal alignment, clinical improvement and length of hospitalization. Patients of the autograft group experienced more postoperative complications, although the difference between the two treatment groups was not statistically significant (15 versus 4.5%, p=0.232). The fusion rate was 100% in both groups. The average lordotic increase of the segmental angle was significantly greater in the ECC group (p<0.05). Other radiological parameters were not significantly different in the two groups. ConclusionCervical reconstruction either with iliac crest autograft and plating or ECC and plating provides good clinical results and similar fusion rates after one- or two-level corpectomy for spondylotic myelopathy. However, the use of ECC obviates donor site complications and provides a more significant increase of lordosis in segmental angle.

Hypoglossal Nerve Injury after Cervical Spine Surgery.

Dear Editor, We have read with great interest the case report entitled nerve palsy as a complication of an anterior approach for cervical spine in the issue of Asian Spine Journal 2015;9(2):295-298, http://dx.doi.org/10.4184/asj.2015.9.2.295 [1]. We would like to commend the authors for their report on a complex and challenging case. Hypoglossal nerve injury often follows soft tissue surgery of the neck but is extremely rare following surgery of the upper cervical spine [1,2]. In this article, the authors cited only one report of hypoglossal nerve palsy after anterior cervical spine surgery through the Smith-Robinson approach [1,2]. Nevertheless, we would like to bring to our readers attention an additional case report on hypoglossal nerve injury following anterior surgery to the upper cervical spine. Saunders et al. [3] reported one incidence of hypoglossal palsy as a long-term sequela in a review of 40 cases of central corpectomy for cervical spondylotic myelopathy. However, we have some concerns regarding the case report and wish to share them with our readers. Hypoglossal nerve injury may be missed unless the deviation of the tongue is noticed carefully. In the cases reported by Saunders et al. [3] and Sengupta et al. [2], the paresis did not recover. Sengupta et al. concluded that together with a review of literature, the hypoglossal nerve should be carefully identified before ligating any large blood vessel in the anterior approach to the upper cervical spine. Spontaneous recovery of hypoglossal palsy may not always be expected. We also agree with the authors that meticulous tissue dissection and hemostasis should be performed intraoperatively to prevent these adverse events. Relaxing the retractors during surgical procedure will minimize traction injury to neural structures. In addition, the patient should be warned about this complication. We highly appreciate the authors' contribution to the increase in our knowledge of this difficult clinical problem.

Change in morphology of intramedullary T2-weighted increased signal intensity after anterior decompressive surgery for cervical spondylotic myelopathy.

Retrospective study. To study the change in morphology of T2-weighted (T2W) increased signal intensity (ISI) and its association with functional outcome after central corpectomy for cervical spondylotic myelopathy (CSM) and ossified posterior longitudinal ligament (OPLL). There are limited data on change in T2W ISI morphology after anterior decompressive surgery. It is unclear whether change in T2W ISI carries prognostic significance in patients with CSM/OPLL. We reviewed patients who underwent central corpectomy for CSM/OPLL between 1996 and 2010, and underwent a follow-up magnetic resonance imaging (MRI) at 6 months or later postoperatively. T2W ISI on sagittal images was classified as type 0 no ISI; type 1, predominantly (>50%) faint with an indistinct border; and type 2, predominantly (>50%) intense with a sharp border. The length of T2W ISI and the presence of T1-weighted hypointensity were also recorded on preoperative and follow-up images. Functional outcomes as measured by the Nurick grade were correlated with change in morphology of MR signal changes. Sixty-four patients (60 males, mean age = 50 ± 1.1 yr) were reviewed. The mean follow-up duration was 29 ± 3.5 months. The majority of patients (71.9%) had no change in the type of ISI at follow-up. The type of ISI improved in 13 patients (20.3%), and worsened in 5 patients (7.8%). The mean length of ISI was 26.2 ± 3.4 mm preoperatively and 13.7 ± 1.8 mm at follow-up in 53 patients (P = 0.002). Change in ISI grade or length was not associated with change in Nurick grade at follow-up (P = 0.74, P = 0.5). The type of T2W ISI does not change, but the length of T2W ISI decreases for the majority of patients undergoing anterior cervical decompression for CSM/OPLL. In our series, change in morphology of T2W ISI did not correlate with functional outcome as measured by Nurick grade. 4.

Answer to the Letter to the Editor of J.M. Duart Clemente et al. concerning “multilevel oblique corpectomy for cervical spondylotic myelopathy preserves segmental motion” by AG Chacko, M Joseph, MK Turel, K Prabhu, RT Daniel, KS Jacob (2012) Eur Spine J. 2012;21(7):1360–1367

We thank J.M. Duart Clemente et al. for their interest in our article and raising important issues. Interestingly, the incidence of preoperative neck pain was low in our series despite this being a younger cohort of patients without degenerated and fused spines. In addition, neck pain was not a complaint noted during the follow-up period though we have not presented this in the results. We agree that the main goal of surgery is decompression for neurological improvement and not motion preservation. Ours was a unique group of younger patients with soft discs that stands in contrast to the older set of patients with degenerated and largely fused spines reported in Western series [1]. Having performed the oblique corpectomy with good outcomes, we noted the preservation of motion in the short term as a secondary finding that has not been reported previously with this technique. We have also documented a reduction in cervical motion with longer follow-up indicating that the body tends to fuse the spine with production of anterior osteophytes in this relentlessly progressive degenerative disease [2]. Furthermore, the analysis of data from our consecutive series of 153 patients demonstrated that the neurological function and thereby functional outcome was markedly improved following oblique corpectomy. This improved status remained without secondary worsening on long-term follow-up [3]. The technique of oblique corpectomy ensures the removal of the entire posterior surfaces of the affected vertebrae compressing the cord at presentation. The subsequent “cervicoarthrosis” that could reform on the long term are predominantly at the anterior surfaces of the vertebrae and cannot, therefore, endanger the decompressed spinal cord. This would explain the lack of progressive neurological deterioration at least due to a compressive element at the segments treated. We agree wholeheartedly that although motion preservation is not the primary objective of this surgery, we could avoid or at least retard the development of adjacent segment disease. Long-term follow-up is, of course, mandatory to ensure that these patients do not develop progressive kyphosis or adjacent segment disease.

Clinico-biomechanical considerations on oblique corpectomy. Response to: Multilevel oblique corpectomy for cervical spondylotic myelopathy preserves segmental motion (by A.G. Chacko et al.)

We read with interest the article by Chacko et al. [1] “Multilevel oblique corpectomy for cervical spondylotic myelopathy preserves segmental motion”; the authors are to be congratulated for their series shown in the article. Certainly, oblique corpectomy described and divulged by George [2] may be an alternative for decompression without fusion in ankylosed spines. It allows for full anterior foraminotomy with direct proximal root control, as well as central canal decompression in patients suffering from stenotic myelopathy. Some complications have been described as Horner’s syndrome, mostly transient. This procedure is interesting for patients that are not candidates for posterior decompressive procedures because of non-lordotic alignment and in whom instability is discarded with preoperative flexion–extension X-rays and not expected because of the degenerated discs and less bone removal, not needing additional instrumentation. This technique requires a learning curve and good patients’ selection, as well as vertebral artery control without remarkable reported vascular complications. We would like to discuss a couple of points. Cervicoarthrosis—the cause of stenotic myelopathy—may be silent, but when it “wakes up” most of the times shows as neck pain. On the other hand, patients treated with anterior decompressive and reconstructive procedures have less postoperative residual axial neck pain than after posterior procedures. According to some other groups which do not restrict the technique to kyphotic alignment, some patients may develop new axial pain (as well as kyphosis) [3], though most of patients with preoperative neck pain improved on pain and most of those without it stayed the same, though few in the latter group worsened a little bit [4]. The goal of surgery is improvement of neurological compromise and decrease in pain, not keeping motion; the need for pain-killers is neither assessed pre and postoperatively nor compared with standard anterior corpectomy and fusion (ACF), so we suggest that in the future it could be investigated whether there is any difference, in patients treated with this technique in comparison with the standard. Another concern is on the biomechanical consequences on the long term. Osteophytes are thought to be the attempt of the body trying to immobilize the unstable and painful segment. The biomechanical study for this surgical technique used non-collapsed disc specimens [5] and quantified the destabilizing effect of it, though kinematics is altered considerably less than that for standard corpectomy (even after plating). Given the kyphosing effect of this technique in the mentioned young population (1:3) with relatively healthy non-collapsed discs and thus mobile function kept, concern raises about what the future holds for these segments; motion preservation may be important specially in young patients, but it should not compromise future neurological function.

Clinical and radiological outcomes in 153 patients undergoing oblique corpectomy for cervical spondylotic myelopathy

Objective. To document the clinical and radiological outcomes in a large series of patients undergoing the oblique cervical corpectomy (OCC) for spondylotic myelopathy. Materials and methods. We retrospectively analyzed our series of 153 patients undergoing OCC for cervical spondylotic myelopathy (CSM) over the last 10 years. A mean clinical follow-up of 3 years was obtained in 125 patients (81.7%), while 117 patients (76.5%) were followed up radiologically. Neurological function was measured by the Nurick grade and the modified Japanese Orthopedic Association score (JOA). Plain radiographs and magnetic resonance images (MRI) were reviewed. Results. Ninety-two percent were men with a mean age of 51 years and a mean duration of symptoms of 18 months. Sixty-one had a single level corpectomy, 66 had a 2-level, 24 had a 3-level, and two had a 4-level OCC. There was statistically significant improvement (p < 0.05) in both the Nurick grade and the JOA score at mean follow-up of 34.6 ± 25.4 months. Permanent Horner's syndrome was seen in nine patients (5.9%), postoperative C5 radiculopathy in five patients (3.3%), dural tear with CSF leak in one patient (0.7%), and vertebral artery injury in one patient (0.7%). Of the 117 patients who were followed up radiologically, five patients (4.3%) developed an asymptomatic kyphosis of the cervical spine while 22 patients (25.6%) with preoperative lordotic spines had a straightening of the whole spine curvature. Conclusions. The OCC is a safe procedure with good outcomes and a low morbidity for treating cervical cord compression due to CSM. This procedure avoids graft-related complications associated with the central corpectomy, but is technically demanding.

Reduction in range of cervical motion on serial long-term follow-up in patients undergoing oblique corpectomy for cervical spondylotic myelopathy

To determine whether motion preservation following oblique cervical corpectomy (OCC) for cervical spondylotic myelopathy (CSM) persists with serial follow-up. We included 28 patients with preoperative and at least two serial follow-up neutral and dynamic cervical spine radiographs who underwent OCC for CSM. Patients with an ossified posterior longitudinal ligament (OPLL) were excluded. Changes in sagittal curvature, segmental and whole spine range of motion (ROM) were measured. Nathan's system graded anterior osteophyte formation. Neurological function was measured by Nurick's grade and modified Japanese Orthopedic Association (JOA) scores. The majority (23 patients) had a single or 2-level corpectomy. The average duration of follow-up was 45 months. The Nurick's grade and the JOA scores showed statistically significant improvements after surgery (p < 0.001). 17% of patients with preoperative lordotic spines had a loss of lordosis at last follow-up, but with no clinical worsening. 77% of the whole spine ROM and 62% of segmental ROM was preserved at last follow-up. The whole spine and segmental ROM decreased by 11.2° and 10.9°, respectively (p ≤ 0.001). Patients with a greater range of segmental movement preoperatively had a statistically greater range of movement at follow-up. The analysis of serial radiographs indicated that the range of movement of the whole spine and the range of movement at the segmental spine levels significantly reduced during the follow-up period. Nathan's grade showed increase in osteophytosis in more than two-thirds of the patients (p ≤ 0.01). The whole spine range of movement at follow-up significantly correlated with Nathan's grade. Although the OCC preserves segmental and whole spine ROM, serial measurements show a progressive decrease in ROM albeit without clinical worsening. The reduction in this ROM is probably related to degenerative ossification of spinal ligaments.

Multilevel oblique corpectomy for cervical spondylotic myelopathy preserves segmental motion

To document the neurological outcome, spinal alignment and segmental range of movement after oblique cervical corpectomy (OCC) for cervical compressive myelopathy. This retrospective study included 109 patients--93 with cervical spondylotic myelopathy and 16 with ossified posterior longitudinal ligament in whom spinal curvature and range of segmental movements were assessed on neutral and dynamic cervical radiographs. Neurological function was measured by Nurick's grade and modified Japanese Orthopedic Association (JOA) scores. Eighty-eight patients (81%) underwent either a single- or two-level corpectomy; the remaining (19%) undergoing three- or four-level corpectomies. The average duration of follow-up was 30.52 months. The Nurick's grade and the JOA scores showed statistically significant improvements after surgery (p < 0.001). The mean postoperative segmental angle in the neutral position straightened by 4.7 ± 6.5°. The residual segmental range of movement for a single-level corpectomy was 16.7° (59.7% of the preoperative value), for two-level corpectomy it was 20.0° (67.2%) and for three-level corpectomies it was 22.9° (74.3%). 63% of patients with lordotic spines continued to have lordosis postoperatively while only one became kyphotic without clinical worsening. Four patients with preoperative kyphotic spines showed no change in spine curvature. None developed spinal instability. The OCC preserves segmental motion in the short-term, however, the tendency towards straightening of the spine, albeit without clinical worsening, warrants serial follow-up imaging to determine whether this motion preservation is long lasting.

Temporal progression and spatial distribution of "normal" prevertebral soft tissue swelling following central corpectomy for cervical spondylotic myelopathy

To document the temporal progression and spatial distribution of prevertebral soft tissue swelling (PSTS) after central corpectomy (CC) and to determine the variables affecting its severity. The natural attributes of PSTS following CC for cervical spondylotic myelopathy (CSM) have not been characterized in literature. PSTS was measured at the C2 level and midpoint of the operated segment on lateral radiographs of the cervical spine taken pre-operatively and post-operatively (day 0, day 3/4, day 5 and day 6/7) in 93 patients with CSM undergoing one to three level uninstrumented CC. Patient's age, weight, Nurick's grade, number of corpectomy levels and intubation time were correlated with the PSTS. Proportionately, the swelling was maximal at the C2 level rather than at the level of CC, on all days, irrespective of the level of surgery. At the C2 level, the increase in PSTS was maximum by day 3/4 (P = 0.0001), whereas at the CC level, the PSTS continued to increase till day 5 (P = 0.0001). PSTS was higher in patients undergoing a three-level CC and in those with inclusion of C4 in the CC (P = 0.002). Patients undergoing CC are at risk for upper airway obstruction mainly at the C2 level in the first 3 days after surgery due to the PSTS. Those undergoing three-level CC, or having inclusion of C4 in the CC, have a greater degree of PSTS and have a higher risk of post-operative airway obstruction.

Central corpectomy in cervical spondylotic myelopathy: Prevertebral soft tissue swelling

Central corpectomy in cervical spondylotic myelopathy: Prevertebral soft tissue swelling

Changes in the range of motion of the cervical spine and adjacent segments at ≥24 months after uninstrumented corpectomy for cervical spondylotic myelopathy

Few clinical studies have described the changes in the range of motion (ROM) of the cervical spine and adjacent segments following central corpectomy. We aimed to quantify the changes in range of motion (ROM) of the cervical spine and the adjacent segments at ≥24 months following uninstrumented central corpectomy (CC) for cervical spondylotic myelopathy (CSM) and to determine the contribution of the adjacent segments to the compensation for loss of motion of the cervical spine following CC. Preoperative and follow-up lateral cervical spine radiographs of 36 patients who underwent CC for CSM between 2001 and 2007 were compared for the ROM of the subaxial cervical spine, superior and inferior adjacent segment. Anterior osteophytes as seen on the radiographs were classified according to Nathan's grading system. The mean duration of follow-up was 48.5 months. At follow-up, the total cervical spine ROM decreased by 18.3° ± 2.2° (p < 0.001), the superior adjacent segment ROM increased by 2.3° ± 0.9° (p = 0.01) and the inferior adjacent segment ROM, measured in 20 cases, increased by 6.2° ± 1.7° (p = 0.01). The superior adjacent segment showed a 70% increase, whereas the inferior adjacent segment showed a 110% increase in mobility. Nathan's grade at the superior or inferior adjacent segment increased in 12 cases. CC significantly reduces the motion of the cervical spine and increases the adjacent segment mobility at intermediate follow-up. The inferior adjacent segment shows greater compensation of motion as compared to the superior adjacent segment in our series. Adjacent segment degeneration as estimated by Nathan's grade was seen in one-third of the cases.

Quality of life assessment after central corpectomy for cervical spondylotic myelopathy: comparative evaluation of the 36-Item Short Form Health Survey and the World Health Organization Quality of Life–Bref

In this study, the authors assessed the construct validity and the reliability of the World Health Organization Quality of Life-Bref (WHOQOL-Bref) questionnaire in patients with cervical spondylotic myelopathy (CSM) and compared the performance of the WHOQOL-Bref and the 36-Item Short Form Health Survey (SF-36) in assessing quality of life (QOL) in patients with CSM. In this prospective study, 70 patients with CSM were assessed preoperatively and again 1 year after central corpectomy using the Nurick scale, the SF-36, and the WHOQOL-Bref. Construct validity and reliability of the WHOQOL-Bref, its responsiveness compared with that of the SF-36, and the correlations between the 2 scales were studied. The WHOQOL-Bref was found to be valid (p < 0.001, Cuzick test for trend between the physical domain of the WHOQOL-Bref and Nurick grade) and reliable (Cronbach alpha > 0.7). It had smaller floor and ceiling effects (ranges 1.4-7.1% and 0-7.1%, respectively) than the SF-36 (ranges 2.9-71.4% and 0-14.1%, respectively). There was significant postoperative improvement in patient scores on all the SF-36 scales (p < 0.001) and the physical, psychological, and environment domains of the WHOQOL-Bref (p < 0.001). The SF-36 scales were more responsive to change (relative efficiency range 0.24-1) than the WHOQOL-Bref domains (relative efficiency range 0.002-0.73). Among scales measuring similar concepts, only the physical functioning and bodily pain scales of the SF-36 had a moderate correlation (r = 0.57 and 0.53, respectively; p < 0.001) with the physical domain of WHOQOL-Bref. Many of the scales of these 2 QOL instruments unexpectedly had a fair correlation with one another (r range = 0.2-0.4). The WHOQOL-Bref, like the SF-36, is valid and reliable in assessing outcome in patients with CSM. It measures impairment in CSM in a more uniform manner than the SF-36, but its domains are less responsive to postoperative changes. Because the WHOQOL-Bref measures different constructs and has additive value, it should be used along with the SF-36 for QOL assessment in patients with CSM.

Two-Level Anterior Cervical Discectomy Versus One-Level Corpectomy in Cervical Spondylotic Myelopathy

A retrospective investigation of clinical and radiologic outcomes after surgical treatment for 2-level cervical spondylotic myelopathy (CSM). The study was undertaken to compare the outcomes of 2 different anterior approach types for 2-level CSM. Specifically, 2-level anterior cervical discectomy and fusion (ACDF) was compared with 1-level anterior cervical corpectomy and fusion (ACCF). The optimal surgical approach for 2-level CSM has not been defined, and thus, the relative merits of 2-level ACDF and 1-level ACCF remain controversial. However, few comparative studies have been conducted on these 2 surgical approaches. The authors reviewed the case histories of 31 patients that underwent surgical treatment for 2-level CSM from 2002 to 2006. Cases of myelopathy because of cervical ossification of posterior longitudinal ligament were excluded. Thirty-one patients (16 men and 15 women) of mean age 54.45 +/- 11.6 years (28 approximately 77) were included. The average follow-up period was 26.23 +/- 15.0 months (12 approximately 63). The authors compared perioperative parameters (hospital stays, bleeding amounts, operation times, complications), clinical parameters (Japanese Orthopedic Association scores, Visual Analog Scale scores for neck and arm pain), and radiologic parameters (total cervical range of motion, segmental range of motion, segmental height, cervical lordosis, fusion rate). Of these above parameters, operation time (P = 0.001) and bleeding amount (P = 0.001) were significantly greater in the ACCF group, whereas segmental height (P = 0.018) and postoperative cervical lordosis (P = 0.009) were significantly lower in the ACCF group. However, other parameters were not significantly different in the 2 groups. Surgical managements of 2-level CSM using ACDF or ACCF were found to be similar in terms of clinical outcomes. However, 2-level ACDF was found to be superior to 1-level ACCF in terms of operation times, bleeding amounts, and radiologic results.