Spine Surgery and Related Research
Online ISSN : 2432-261X
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Showing 1-13 articles out of 13 articles from the selected issue
REVIEW ARTICLE
  • William Luo, Christina Cui, Sina Pourtaheri, Steven Garfin
    2018 Volume 2 Issue 3 Pages 163-168
    Published: July 25, 2018
    Released: July 27, 2018
    [Advance publication] Released: April 07, 2018
    JOURNALS FREE ACCESS

    Introduction: Vertebral compression fracture incidence is rising with the growth of the geriatric population and is one of the leading disabilities in healthcare. However, the literature is conflicted on the benefits of vertebral augmentation versus nonoperative care for these fractures. The purpose of the current study was to perform a review of all meta-analyses in the literature comparing vertebral augmentation to nonoperative care and descriptively report the results.

    Methods: A review of all meta-analyses evaluating trials of vertebral augmentation compared with nonoperative care was performed. The primary outcome studied was pain. Secondary outcomes were quality of life (QoL) metrics and functional outcomes.

    Results: Ten studies met the inclusion criteria. Besides two sham procedure studies, the remaining literature concluded that vertebral augmentation was superior to nonoperative care for reducing back pain. The reporting of secondary outcomes, such as QoL metrics and functional outcomes, was heterogeneous among the studies. Studies that reported these secondary outcomes, however, did identify some early benefit in vertebral augmentation.

    Conclusions: The current literature suggests vertebral augmentation is more effective in improving pain outcomes compared with nonoperative management. While more studies are needed to conclusively assess vertebral augmentation's efficacy in improving functional outcome and QoL, the meta-analyses surveyed here suggest that at least some benefit exists when assessing these two outcomes.

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  • Shigeru Hirabayashi, Tomoaki Kitagawa, Iwao Yamamoto, Kazuaki Yamada, ...
    2018 Volume 2 Issue 3 Pages 169-176
    Published: July 25, 2018
    Released: July 27, 2018
    [Advance publication] Released: February 28, 2018
    JOURNALS FREE ACCESS

    Various methods via anterior or posterior approach with or without spinal stabilization have been performed in accordance with the level and configuration of ossification of the posterior longitudinal ligament (OPLL) as the decompression surgery for thoracic myelopathy due to OPLL. Among them, anterior decompression at the middle thoracic level (T4/T5-T7/T8) is especially difficult to perform because of the special anatomical structures, where the spinal alignment is kyphotic and the thoracic cage containing circulatory-respiratory organs exist nearby. Of the anterior decompression procedures at this level, the posterior approach has various advantages compared to the anterior one. In the anterior approach, the procedure is complicated and the effect of decompression of the spinal cord can be obtained only by direct resection or anterior floating of the OPLL. However, complications such as spinal cord injury and dural tear are most likely to occur at that time. On the contrary, in the posterior approach, the procedure is simple, and various options to obtain decompression can be selected from, these are, laminectomy, laminoplasty, dekyphosis surgery, staged decompression surgery (Tsuzuki's method), circumferential decompression via posterior approach alone (Ohtsuka's method), and circumferential decompression via combined posterior and anterior approaches (Tomita's method). Among them, in laminectomy, laminoplasty, and dekyphosis surgery, anterior decompression can be obtained to some extent without performing direct procedure on the OPLL. In Ohtsuka's method, complete decompression can be obtained via posterior approach alone, although it is somewhat technically demanding. It is preferable to drop the shaved down and separated OPLL anteriorly instead of trying to remove it completely to avoid complications, especially in patients with severe adhesion between the dura mater and OPLL.

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ORIGINAL ARTICLE
  • Keiji Nagata, Yuyu Ishimoto, Shinichi Nakao, Shoko Fujiwara, Toshiko M ...
    2018 Volume 2 Issue 3 Pages 177-185
    Published: July 25, 2018
    Released: July 27, 2018
    [Advance publication] Released: March 15, 2018
    JOURNALS FREE ACCESS

    Introduction: The aims of the present study were 1) to examine the association between neck and shoulder pain (NSP) and lifestyle in the general population and 2) to examine if sagittal spino-pelvic malalignment is more prevalent in NSP.

    Methods: A total of 107 volunteers (mean age, 64.5 years) were recruited in this study from listings of resident registrations in Kihoku region, Wakayama, Japan. Feeling pain or stiffness in the neck or shoulders was defined as an NSP. The items studied were: 1) the existence or lack of NSP and their severity (using VAS scale), 2) Short Form-36 (SF-36), 3) Self-Rating Questionnaire for Depression (SRQ-D), 4) Pain Catastrophizing Scale (PCS), 5) a detailed history consisting of 5 domains as being relevant to the psychosocial situation of patients with chronic pain, 6) A VAS of pain and numbness to the arm, and from thoracic region to legs. The radiographic parameters evaluated were also measured. Participants with a VAS score of 40 mm or higher and less were divided into 2 groups. Association of SF-36, SRQ-D, and PCS with NSP were assessed using multiple regression analysis.

    Results: In terms of QoL, psychological assessment and a detailed history, bodily pain in SF-36, SRQ-D, and family stress were significantly associated with NSP. A VAS of pain and numbness to the arm, and from thoracic region to legs, was significantly associated with NSP. There were no statistical correlations between the VAS and radiographic parameters of the cervical spine. Among the whole spine sagittal measurements, multiple logistic regression analysis showed that sacral slope (SS) and sagittal vertical axis (SVA) were significantly associated with NSP.

    Conclusion: In this study, we showed the factors associated with NSP. Large SS and reduced SVA were significantly associated with NSP, while cervical spine measurements were not.

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  • Kiyonori Yo, Eiki Tsushima, Yosuke Oishi, Masaaki Murase, Shoko Ota, Y ...
    2018 Volume 2 Issue 3 Pages 186-196
    Published: July 25, 2018
    Released: July 27, 2018
    [Advance publication] Released: February 28, 2018
    JOURNALS FREE ACCESS

    Introduction: Several measurement methods designed to provide an understanding of cervical sagittal alignment have been reported, but few studies have compared the reliabilities of these measurement methods. The purpose of the present study was to investigate the intraexaminer and interexaminer reliabilities of several cervical sagittal alignment measurement methods and of the rotated cervical spine using plain lateral cervical spine X-rays of patients with cervical spine disorders.

    Methods: Five different measurement methods (Borden's method; Ishihara index method (Ishihara method); C2-7 Cobb method (C2-7 Cobb); posterior tangent method: absolute rotation angle C2-7 (ARA); and classification of cervical spine alignment (CCSA)) were applied by seven examiners to plain lateral cervical spine X-rays of 20 patients (10 randomly extracted cases from a rotated cervical spine group and 10 from a nonrotated group) with cervical spine disorders. Case 1 and Case 2 intraclass correlation coefficients (ICCs) were used to analyze intraexaminer and interexaminer reliabilities. The necessary number of measurements and the necessary number of examiners were also determined. The target coefficient of correlation was set at ≥0.81 (almost perfect ICC).

    Results: In both groups, an ICC (1, 1) ≥ 0.81 was obtained with Borden's method, the Ishihara method, C2-7 Cobb, and ARA by all examiners. The necessary number of measurements was 1. With CCSA, a kappa coefficient of at least 0.9 was obtained. In both groups, with Borden's method, the Ishihara method, C2-7 Cobb, and ARA, the ICC (2, 1) was ≥0.9, indicating that the necessary number of examiners was 1. The standard error of measurement (SEM) was lowest with Borden's method, and the Ishihara method and C2-7 Cobb had almost the same values.

    Conclusions: Among cervical sagittal alignment measurement methods for cervical spine disorders, regardless of cervical spine rotation, Borden's method, Ishihara method, and C2-7 Cobb offer stronger reliability in terms of the ICC and SEM.

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  • Katsuhito Yoshioka, Hideki Murakami, Satoru Demura, Satoshi Kato, Nori ...
    2018 Volume 2 Issue 3 Pages 197-201
    Published: July 25, 2018
    Released: July 27, 2018
    [Advance publication] Released: March 15, 2018
    JOURNALS FREE ACCESS

    Introduction: The majority of diffuse idiopathic skeletal hyperostosis (DISH) involving the anterior margin of the cervical vertebrae is asymptomatic, but it can cause dysphagia. Improvements in swallowing after surgical treatment have been reported in several case series. However, the appropriate amount of osteophyte resection for this disease in terms of the pathophysiology of dysphagia is still unknown. The current report describes the appropriate surgical procedure for dysphagia secondary to anterior cervical hyperostosis, and discusses the etiology of dysphagia.

    Methods: This is a retrospective review of four patients who presented with complaints of dysphagia secondary to anterior cervical hyperostosis. All patients underwent videofluoroscopic esophagrams (VFEs) to identify the specific region associated with the dysphagia. Esophageal obstruction was present at C3-4 in two patients and at C4-5 in two patients. Three patients underwent localized and limited resection of the anterior cervical osteophytes. One patient underwent total resection of the anterior cervical osteophytes, because re-ossification had occurred after a previous resection.

    Results: Postoperative VFE demonstrated an improvement in swallowing in the three patients who underwent limited resection of the osteophytes. The patient who underwent total resection of the osteophytes did not experience a full recovery of normal swallowing function. We concluded that the dysphagia was caused by both osteophyte obstruction and neuropathy resulting from the previous surgery or inflammation secondary to osteophyte irritation.

    Conclusions: Localized and limited resection of anterior cervical osteophytes is recommended and should be considered for patients with dysphagia from anterior cervical hyperostosis.

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  • Satoshi Baba, Yoshihiro Matsumoto, Shinji Tomari, Takahiro Yasuhara, H ...
    2018 Volume 2 Issue 3 Pages 202-209
    Published: July 25, 2018
    Released: July 27, 2018
    [Advance publication] Released: March 15, 2018
    JOURNALS FREE ACCESS

    Introduction: Several reports have demonstrated the surgical treatment strategy for patients with dialysis-associated spondylosis in the cervical spine (CDAS) with destructive spondyloarthropathy (DSA). However, studies focusing on the clinical outcome of patients with CDAS without DSA remain scarce. We aimed to review the treatment strategy of patients with CDAS but without DSA.

    Methods: The clinical data and surgical records of consecutive patients with CDAS without DSA (n = 9; D-group) and cervical spondylotic myelopathy (CSM) (n = 30; C-group) who underwent modified double-door laminoplasty (DDL) were reviewed retrospectively. We investigated four radiologic factors in the pre-and postoperative periods that have been reported to be the risk factors for worsening of clinical symptoms in various studies and examined statistical comparison between the D and C groups.

    Results: In the D group, the pre- versus postoperative C2-C7 sagittal angles were not significantly different, and only two patients (22%) had kyphosis postoperatively. There was a significant difference in the pre- and postoperative C2-C7 angles in the two groups (P = 0.031).

    Regarding the change in segmental alignment, the local open angle increased at the C4/C5 level in the D group. Also there was a significant difference in the local angles between the two groups at C4/5 and C5/6 (P = 0.00038, and 0.037), suggesting that postoperative segmental mobility at C4/5 and C5/6 was higher in the D group than in the C group.

    Conclusions: In the present study, DDL in patients with CDAS without DSA did not adversely affect the postoperative alignment and stability compared with CSM patients with CSM. However, patients in the D group may have a chance to develop DSA change at the C4/5 level in the future, and careful long-term follow-up is warranted.

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  • Yuji Matsuoka, Kenji Endo, Hirosuke Nishimura, Hidekazu Suzuki, Yasuno ...
    2018 Volume 2 Issue 3 Pages 210-214
    Published: July 25, 2018
    Released: July 27, 2018
    [Advance publication] Released: March 15, 2018
    JOURNALS FREE ACCESS

    Background: Preoperative cervico-thoracic kyphosis and cervical regional positive imbalance are the risk factors for postoperative cervical kyphosis after expansive laminoplasty (ELAP). However, the relationship between preoperative global sagittal spinal alignment and postoperative cervical kyphosis in patients with cervical ossification of the posterior longitudinal ligament (OPLL) is unclear. The purpose of this study was to investigate the relationship between the onset of postoperative cervical kyphosis after ELAP and the preoperative global spinal sagittal alignment in patients with OPLL with normal sagittal spinal alignment.

    Methods: Sixty-nine consecutive patients without preoperative cervical kyphosis who underwent ELAP for OPLL and cervical spondylotic myelopathy (CSM) were enrolled. The global sagittal alignment radiography preoperatively and 1 year postoperatively were examined. The subjects were divided into a postoperative cervical lordosis group (LG) or a kyphosis group (KG) at 1 year postoperatively. The preoperative global sagittal spinal alignment between LG and KG in CSM and OPLL was compared.

    Results: The occurrence of cervical kyphosis after ELAP was 7 of 27 cases (25.9%) in OPLL and 13 of 42 cases (31.0%) in CSM. In patients with CSM in the KG, C7 the sagittal vertical axis (SVA) was smaller than in the LG. In patients with cervical OPLL in the KG, C2-C7 angle, C2-C7 SVA, and thoracic kyphosis (TK) were smaller than those in the LG. In OPLL, the age of the KG was younger than that of LG; however, this was not a significant difference in CSM.

    Conclusion: In patients with cervical OPLL without preoperative global spinal sagittal imbalance, preoperative small C2-C7 angle, C2-C7 SVA, TK, and younger age were typical characteristics of postoperative cervical kyphosis after ELAP.

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  • Takashi Hirai, Toshitaka Yoshii, Hiroyuki Inose, Tsuyoshi Yamada, Masa ...
    2018 Volume 2 Issue 3 Pages 215-220
    Published: July 25, 2018
    Released: July 27, 2018
    [Advance publication] Released: March 15, 2018
    JOURNALS FREE ACCESS

    Introduction: Patients treated with revision surgery after lumbar decompression with fusion typically have persistent low back pain and lower extremity numbness compared with patients treated with only primary surgery. No well-designed study has investigated the persistence and degree of pain after revision surgery following instrumented operation. The purpose of this study is to compare residual pain among patients who underwent reoperation and those who underwent only primary surgery for lumbar degenerative disorder using patient-based evaluation.

    Methods: We reviewed 350 consecutive patients (143 men, 207 women, mean age 63 years) treated with primary lumbar instrumented surgery between October 2010 and February 2014 at our institution and followed up for ≥2 years postoperatively. Patients were categorized into three groups based on number of levels fused: 1-segment, 2-segment, and ≥3-segment fusion (1F, 2F, and ≥3F groups, respectively). We used the Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) and visual analog scales (VASs) for low back pain and lower extremity pain to evaluate pain intensity pre- and postoperatively.

    Results: Salvage surgery for late-phase complications was required in 5 cases (2.4%), 6 cases (11.3%), and 11 cases (12.1%) in the 1F, 2F, and ≥3F groups, respectively. In the 1F and 2F groups, patients treated with revision surgery had unsatisfactory improvement in the pain domain of JOABPEQ and VASs for low back pain and lower extremity pain compared with patients with only primary short fusion surgery. The ≥3F group showed no significant differences between patients who underwent reoperation and those who underwent only primary surgery.

    Conclusion: Low back pain and lower extremity pain often persist after revision surgery in patients treated with short fusion (≤2-segment) operation. We need to follow pain states in such patients.

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  • Kazuyuki Otani, Shigeo Shindo, Koichi Mizuno, Kazuo Kusano, Norihiko M ...
    2018 Volume 2 Issue 3 Pages 221-225
    Published: July 25, 2018
    Released: July 27, 2018
    [Advance publication] Released: March 15, 2018
    JOURNALS FREE ACCESS

    Introduction: Pedicle subtraction osteotomy (PSO) is performed to correct sagittal plane deformity. This procedure is useful with revision cases in which the number of intact discs for correction is limited.

    Methods: Forty-four patients (10 male and 34 female) with minimum follow-up of 2 years were reviewed; all had undergone PSO revision surgery for kyphosis following previous lumbar fusion surgery. The average age at operation was 72.8 years (range 42-85 years), and the average follow-up period was 4.1 years (2-9 years). The average fusion level was 7.5 (4-13 level), and the average previously fused level was 2.4 (1-7 level).

    Results: The average operation time was 424 min, and average blood loss was 2880 g. The average JOA score of 14.0 before operation changed to 21.8 at 1-year follow-up and to 20.7 at final follow-up. The average recovery rate at final follow-up was 45.7%. Four patients underwent re-operations for proximal junctional kyphosis and 3 patients for rod fracture. The fusion rate was 88.6%, and 13 patients (29.5%) developed subsequent vertebral fracture. The average PI-LL (Pelvic incidence minus Lumbar lordosis) at pre-op of 52.9 degrees changed to 3.8 degrees at post-op, to 13.4 degrees at 1-year follow-up, and to 14.8 degrees at final follow-up. The average correction at the PSO site was 36.0 degrees at post-op, 36.7 degrees at 1-year follow-up, and 37.0 degrees at final follow-up. The average sagittal vertical axis at pre-op of 145.0 mm decreased to 51.2 mm at 1-year follow-up; however, it increased to 75.3 mm at final follow-up.

    Conclusion: PSO for correction of kyphosis following previous lumbar fusion surgery was an effective procedure without correction loss at the local osteotomy site; however, its surgical invasiveness and complication rate were high. Subsequent vertebral fracture, adjacent segment degeneration, and rod fracture contribute to deterioration of outcome that is evident at long-term follow-up.

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  • Costansia Bureta, Hiroyuki Tominaga, Takuya Yamamoto, Ichiro Kawamura, ...
    2018 Volume 2 Issue 3 Pages 226-229
    Published: July 25, 2018
    Released: July 27, 2018
    [Advance publication] Released: March 15, 2018
    JOURNALS FREE ACCESS

    Introduction: One complication after scoliosis surgery is ileus; however, few reports have described the frequency of and risk factors for this complication. We conducted a retrospective clinical study with logistic regression analysis to confirm the frequency of and risk factors for ileus after scoliosis surgery.

    Methods: After a retrospective review of data from patients who underwent surgical correction of spinal deformity from 2009 to 2014, 110 cases (age range, 4-73 yr; median, 14 yr) were included in the study. We defined postoperative ileus (POI) as a surgical complication characterized by decreased intestinal peristalsis and the absence of stool for more than 3 days postoperatively. Various parameters were compared between patients with POI and those without POI. Logistic regression analysis was performed to assess the risk factors associated with ileus; a P value of <0.05 was considered statistically significant.

    Results: Fifteen of 110 (13.6%) cases developed POI. The median height, weight, operation time, and blood loss volume of the patients with versus without POI were 146 versus 152 cm, 39.0 versus 44.0 kg, 387 versus 359 min, and 1590 versus 1170 g, respectively. There were no significant differences between patients with versus without POI in the measured parameters, with the exception of patient height, bed rest period, and presence of neuromuscular scoliosis. Multiple logistic regression analysis revealed neuromuscular scoliosis as a significant risk factor for POI (odds ratio, 4.21; 95% CI, 1.23-14.40).

    Conclusions: Our findings indicate a high probability of POI after scoliosis surgery, with an incidence of 13.6%. Neurogenic scoliosis, but not lowest instrumented vertebra or correction rate, was a risk factor for POI after scoliosis surgery. Digestive symptoms should be carefully monitored after surgery, particularly in patients with neuromuscular scoliosis.

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  • Sumihisa Orita, Miyako Suzuki, Kazuhide Inage, Yasuhiro Shiga, Kazuki ...
    2018 Volume 2 Issue 3 Pages 230-235
    Published: July 25, 2018
    Released: July 27, 2018
    [Advance publication] Released: April 07, 2018
    JOURNALS FREE ACCESS

    Introduction: Osteoporosis can produce a persistent state of pain known as osteoporotic pain. One proposed mechanism of this pathology is increased calcitonin gene-related peptide (CGRP; a marker related to inflammatory pain) expression in the dorsal root ganglia (DRG) innervating osteoporotic vertebrae. Alternatively, a previous study revealed that axial loading caused osteoporotic pain in a rodent model of coccygeal vertebrae compression. Because this compression model is associated with trauma, additional mechanistic studies of osteoporotic pain in the absence of trauma are required. The current study aimedto evaluate the expression and relative distribution of transient receptor potential vanilloid 4 (TRPV4), a pain-related mechanoreceptor, in ovariectomized (OVX) osteoporotic rats.

    Methods: CGRP-immunoreactive (-ir) and TRPV4-ir DRG neurons innervating the L3 vertebrae of Sprague-Dawley rats were labeled with a neurotracer, FluoroGold. Intravertebral pH was also measured during the neurotracer procedure. TRPV4-ir/CGRP-ir FluoroGold-positive DRG neurons were quantified in sham control and OVX rats (n = 10, ea). The threshold for statistical significance was set at P < 0.05.

    Results: There was no statistical difference in the number of FluoroGold-positive DRG neurons between groups; however, there were significantly more CGRP-ir/TRPV4-ir FluoroGold-positive DRG neurons in the OVX group compared with the sham control group (P < 0.05) as well as the significantly increased molecular production of each peptide. Intravertebral pH was also lower in the OVX group compared with the sham control group (P < 0.05).

    Conclusion: Sensory neurons innervating osteoporotic vertebrae exhibited increased expression of co-localized CGRP and TRPV4 in OVX osteoporotic rats. Additionally, intravertebral pH was low in the vicinity osteoporotic vertebrae. Considering that TRPV4 is a mechanosensitive nociceptor that is activated in acidic environments, its upregulation may be associated with the pathology of osteoporotic pain derived from microinflammation involved in osteoporosis.

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TECHNICAL NOTE
  • Apiruk Sangsin, Hideki Murakami, Takaki Shimizu, Satoshi Kato, Satoru ...
    2018 Volume 2 Issue 3 Pages 236-242
    Published: July 25, 2018
    Released: July 27, 2018
    JOURNALS FREE ACCESS

    Introduction: L5 spondylectomy for the treatment of spinal tumor is a technically demanding surgery because of the complex anatomy of major vessels, the obscurity of the posterior exposure from the iliac wings, and the increased comparative size of the L5 vertebral body. In this study, we present a surgical technique of L5 spondylectomy, vertebral body removal, and anterior reconstruction for a case with solitary spinal metastatic renal cell carcinoma (RCC).

    Technical Note: A 54-year-old man underwent right total nephrectomy for RCC one year ago. At the one-year postoperative follow-up, CT scan and MRI revealed a solitary L5 spinal metastasis. A two-stage posteroanterior approach was performed. To facilitate vertebral body removal, transverse processes were separated from the vertebral body by using the posterior approach. On the basis of the anterior approach, the vertebral body was removed via the interval space between the left common iliac vessels. Reconstruction was performed by using a liquid-nitrogen-frozen, tumor-bearing bone mixed with an autogenous bone graft in an expandable titanium cage.

    Results: No intraoperative complications were observed. Postoperatively, the patient exhibited muscle weakness in the tibialis anterior and extensor hallucis longus bilaterally but improved with time. Seven months after the operation, the patient was able to walk independently. At the recent 2.5-year follow-up, the local recurrence of lesions was nonexistent. The bone graft had fused with the adjacent vertebrae.

    Conclusion: This report described a novel technique for L5 spondylectomy that can facilitate safe L5 vertebral body removal and demonstrated the effectiveness of liquid-nitrogen-frozen, tumor-bearing bone mixed with autogenous bone graft in anterior reconstruction both in terms of oncologic safety and biological healing.

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CASE REPORT
  • Seiichi Odate, Jitsuhiko Shikata, Tsunemitsu Soeda
    2018 Volume 2 Issue 3 Pages 243-247
    Published: July 25, 2018
    Released: July 27, 2018
    [Advance publication] Released: April 07, 2018
    JOURNALS FREE ACCESS

    Introduction: Dropped head syndrome (DHS) after cervical laminoplasty (LAMP) is a rare complication, and no etiologies or surgical strategies have been reported. We present a patient who developed catastrophic DHS after LAMP despite having preoperative cervical lordosis that is known to be suitable for LAMP. We describe a hypothesis concerning the possible mechanism responsible for the DHS and a surgical strategy for relieving it.

    Case Report: A 76-year-old woman underwent LAMP for cervical spondylotic myelopathy. She achieved satisfactory improvement of neurological symptoms immediately after surgery. However, her neurological symptoms began to gradually deteriorate. She exhibited a dropped head and complained of difficulty maintaining horizontal gaze. Postoperative images showed a focal cervical kyphotic deformity causing anterior shift of the head, and recurrence of spinal cord compression was observed. She underwent additional surgeries for three times, but none of them restored her to baseline status. Retrospectively, the preoperative loading axis of the head existed anteriorly, and she also had a high T1 slope because of rigid thoracic kyphosis. Her preoperative hyper cervical lordosis was compensation for the global spinal malalignment. After LAMP, in accordance with decreases in her cervical lordosis, her head shifted anteriorly. The abnormal lever arm acting on the neck put further stress on the neck extensors, and the overstretched neck extensors possibly no longer generated enough power to raise the head. Uncompensated very high T1 slope because of marked thoracic kyphosis plus invasion of the posterior extensor mechanism by LAMP may have contributed to her catastrophic DHS development.

    Conclusions: In the treatment of cervical myelopathy, posterior decompression alone should be applied carefully to elderly patients with cervical sagittal imbalance even if they have apparent cervical lordosis. Once DHS occurs because of cervical sagittal imbalance, normalization of global spinal balance through corrective osteotomy may be indispensable for a successful outcome.

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