Cervical spondylotic myelopathy associated with kyphosis or sagittal sigmoid alignment: outcome after anterior or posterior decompression

Object The effects of sagittal kyphotic deformities or mechanical stress on the development of cervical spondylotic myelopathy, or the reduction and fusion of kyphotic sagittal alignment have not been consistently documented. The aim in this study was to determine the effects of kyphotic sagittal alignment of the cervical spine in terms of neurological morbidity and outcome after 2 types of surgical intervention. Methods The authors retrospectively reviewed the records of 476 patients who underwent cervical spine surgeries for spondylotic myelopathy between 1993 and 2006 at their university medical center. Among these were identified 43 patients—30 men and 13 women, with a mean age of 58.8 years—who had cervical kyphosis exceeding 10° on preoperative sagittal lateral radiographs obtained in the neutral position, and their cases were analyzed in this study. Anterior decompression with interbody fusion was conducted in 28 patients, and en bloc open-door C3–7 laminoplasty in 15 patients. Both pre- and postoperative neurological, radiographic, and MR imaging findings were assessed in both surgical groups. Results The mean preoperative kyphotic angle in all 43 patients was 15.9 ± 5.9° in the neutral position. Segmental instability was noted in 26 patients (61%) and reversed dynamic spinal canal stenosis at the level above the local kyphosis in 22 (51%). Preoperative T2-weighted MR images showed high-intensity signal within the cord at and around the level of maximal compression or segmental instability in 28 patients (65%). The mean kyphotic angle in both the neutral and flexion positions was significantly smaller at 4–6 weeks after surgery in the anterior spondylectomy group than in the laminoplasty group (p < 0.001). Furthermore, the angle in the neutral position was significantly smaller on follow-up in the anterior spondylectomy group than in the laminoplasty group (p = 0.034). The transverse area of the spinal cord was significantly larger in the anterior spondylectomy group than in the laminoplasty group on follow-up (p = 0.037). Preoperative neurological scores (assessed using the Japanese Orthopaedic Association scale) and improvement on follow-up ≥ 2 years after treatment (average 3.3 years) were not significantly different between the 2 groups; however, there was a significant difference in Japanese Orthopaedic Association score at 4–6 weeks postoperatively (p = 0.047). Conclusions Kyphotic deformity and mechanical stress in the cervical spine may play an important role in neurological dysfunction. In a select group of patients with kyphotic deformity ≥ 10°, adequate correction of local sagittal alignment may help to maximize the chance of neurological improvement.

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Changes in Cervical Spine Curvature after Uninstrumented One- and Two-level Corpectomy in Patients with Spondylotic Myelopathy

Neurosurgery ◽

10.1227/01.neu.0000054218.50113.40 ◽

2003 ◽

Vol 52 (4) ◽

pp. 799-805 ◽

Cited By ~ 51

Author(s):

Vedantam Rajshekhar ◽

Moses Joseph Arunkumar ◽

Samson Sujith Kumar

Keyword(s):

Cervical Spine ◽

Cervical Spondylotic Myelopathy ◽

Sagittal Alignment ◽

X Rays ◽

Kyphotic Angle ◽

X Ray ◽

Spine Curvature ◽

Whole Spine ◽

Over Time

Abstract OBJECTIVE We studied changes in the cervical spine curvature in patients with cervical spondylotic myelopathy who underwent one- or two-level central corpectomy and iliac bone grafting without the use of instrumentation. METHODS Curvature of the fused segment and of the whole cervical spine was evaluated on preoperative and follow-up x-rays in 93 patients (30 underwent one-level corpectomy, and 63 underwent two-level corpectomy). In 59 patients, the changes in the cervical spine curvature were studied using one follow-up x-ray; in the other 34 patients, the changes were studied on x-rays obtained at two or more follow-up visits. The sagittal alignment of the fused segment was categorized as lordotic (>+5 degrees), straight (+5 to −5 degrees) or kyphotic (>−5 degrees). The whole spine curvature also was recorded as lordotic, straight, or kyphotic. RESULTS At a mean follow-up of 22.2 months (range, 6–71 mo), there was a mean change of −10.4 degrees in the segmental curvature (P< 0.001). The fused segment sagittal alignment also worsened (lordotic angles becoming straight or kyphotic and straight angles becoming kyphotic) in 44 patients (47%)(P< 0.001). However, serial studies in 34 patients (mean first and last follow-ups, 11.9 and 30.8 mo, respectively) did not demonstrate significant worsening of the kyphotic angle or the sagittal alignment over time (P= 0.9). Whole spine curvature worsened in 33 (35%) of the 93 patients (P< 0.001); serial studies did not reveal a significant change (P= 0.9). Patients improved in their functional status from a preoperative mean Nurick grade of 2.9 (range, 1–5) to a follow-up mean Nurick grade of 1.5 (range, 0–4) (P< 0.001). Patients with a kyphotic change in their whole spine curvature (n = 33) and those without such change (n = 60) had a similar functional outcome (mean change in Nurick grade, 1.5 and 1.4, respectively). CONCLUSION Cervical spine curvature tended to undergo a kyphotic change at the fused segment in 47% of patients and a kyphotic change of the whole spine curvature in 35% of patients who underwent one- or two-level uninstrumented central corpectomy. This kyphotic change in the cervical spine, which stabilizes within 1 year after surgery, is not progressive, and it does not affect neurological outcome in these patients.

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Prospective cohort study of mild cervical spondylotic myelopathy without surgical treatment

Journal of Neurosurgery Spine ◽

10.3171/2011.8.spine11395 ◽

2012 ◽

Vol 16 (1) ◽

pp. 8-14 ◽

Cited By ~ 36

Author(s):

Masatoshi Sumi ◽

Hiroshi Miyamoto ◽

Teppei Suzuki ◽

Shuichi Kaneyama ◽

Takako Kanatani ◽

...

Keyword(s):

Spinal Cord ◽

Surgical Treatment ◽

Mr Imaging ◽

Cervical Spondylotic Myelopathy ◽

Japanese Orthopaedic Association ◽

Rank Test ◽

Imaging Findings ◽

Significant Difference ◽

The Mean

Object Because the main pathology of cervical spondylotic myelopathy (CSM) is spinal cord damage due to compression, surgical treatment is usually recommended to improve patient symptoms and prevent exacerbation. However, lack of clarity of prognosis in cases that present with insignificant symptoms, particularly those of mild CSM, lead one to question the veracity of this course of action. The purpose of this study was to elucidate the prognosis of mild CSM without surgical intervention by evaluation of clinical symptoms and MR imaging findings. Methods Sixty cases of mild CSM (42 males and 18 females, average age 57.2 years) presenting with scores of 13 or higher on the Japanese Orthopaedic Association (JOA) scale were treated initially by in-bed Good Samaritan cervical traction without surgery. These patients were enrolled between 1995 and 2003 and followed up periodically until the date of myelopathy deterioration or until the end of March 2009. The deterioration of myelopathy was defined as a decline in JOA score to less than 13 with a decrease of at least 2 points. As a prognostic factor, the authors used their classification of spinal cord shapes at their lateral sides on axial T1-weighted MR imaging. “Ovoid deformity” was classified as a situation in which both sides were round and convex, and “angular-edged deformity” where one or both sides exhibited an acute-angled lateral corner. The duration of follow-up was assessed as the tolerance rate of mild CSM using Kaplan-Meier survival analysis and compared between 2 groups classified by MR imaging findings. Furthermore, differences between groups were analyzed by various applications of the log-rank test. Results Of the initial 60 cases, follow-up records existed for 55, giving a follow-up rate of 91.7% (38 males and 17 females, average age 56.1 years). The mean JOA score at end point was 14.1, which was not statistically different from the mean of 14.5 at the initial visit. Deterioration in myelopathy was observed in 14 (25.5%) of 55 cases, whereas 41 (74.5%) of 55 cases maintained mild extent myelopathy without deterioration through the follow-up period (mean 94.3 months). The total tolerance rate of mild CSM was 70%. However, there was a significant difference in the tolerance rate between the cases with angular-edged deformity (58%) and cases with ovoid deformity (95%; p = 0.049). Conclusions The tolerance rate of mild CSM was 70% in this study, which proved that the prognosis of mild CSM without surgical treatment was relatively good. However, the tolerance rate of the cases with angular-edged deformity was 58%. Therefore, surgical treatment should be considered when mild CSM cases show angular-edged deformity on axial MR imaging, even if patients lack significant symptoms.

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“Skip” corpectomy in the treatment of multilevel cervical spondylotic myelopathy and ossified posterior longitudinal ligament

Journal of Neurosurgery Spine ◽

10.3171/2009.7.spine08965 ◽

2010 ◽

Vol 12 (1) ◽

pp. 33-38 ◽

Cited By ~ 26

Author(s):

Sedat Dalbayrak ◽

Mesut Yilmaz ◽

Sait Naderi

Keyword(s):

Vertebral Body ◽

Cervical Spondylotic Myelopathy ◽

Japanese Orthopaedic Association ◽

Posterior Longitudinal Ligament ◽

Japanese Orthopaedic Association Score ◽

Cervical Lordosis ◽

The Mean ◽

Ossified Posterior Longitudinal Ligament ◽

Multilevel Cervical Spondylotic Myelopathy

Object The authors reviewed the results of “skip” corpectomy in 29 patients with multilevel cervical spondylotic myelopathy (CSM) and ossified posterior longitudinal ligament (OPLL). Methods The skip corpectomy technique, which is characterized by C-4 and C-6 corpectomy, C-5 osteophytectomy, and C-5 vertebral body preservation, was used for decompression in patients with multilevel CSM and OPLL. All patients underwent spinal fixation using C4–5 and C5–6 grafts, and anterior cervical plates were fixated at C-3, C-5, and C-7. Results The mean preoperative Japanese Orthopaedic Association score increased from 13.44 ± 2.81 to 16.16 ± 2.19 after surgery (p < 0.05). The cervical lordosis improved from 1.16 ± 11.74° to 14.36 ± 7.85° after surgery (p < 0.05). The complications included temporary hoarseness in 3 cases, dysphagia in 1 case, C-5 nerve palsy in 1 case, and C-7 screw pullout in 1 case. The mean follow-up was 23.2 months. The final plain radiographs showed improved cervical lordosis and fusion in all cases. Conclusions The authors conclude that the preservation of the C-5 vertebral body provided an additional screw purchase and strengthened the construct. The results of the current study demonstrated effectiveness and safety of the skip corpectomy in patients with multilevel CSM and OPLL.

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Improvement in cervical lordosis and sagittal alignment after vertebral body sliding osteotomy in patients with cervical spondylotic myelopathy and kyphosis

Journal of Neurosurgery Spine ◽

10.3171/2020.3.spine2089 ◽

2020 ◽

Vol 33 (3) ◽

pp. 307-315 ◽

Cited By ~ 1

Author(s):

Dong-Ho Lee ◽

Choon Sung Lee ◽

Chang Ju Hwang ◽

Jae Hwan Cho ◽

Jae-Woo Park ◽

...

Keyword(s):

Vertebral Body ◽

Cervical Spondylotic Myelopathy ◽

Sagittal Alignment ◽

Japanese Orthopaedic Association ◽

Vertical Axis ◽

Sacral Slope ◽

Cervical Lordosis ◽

Sagittal Vertical Axis ◽

Segmental Lordosis

OBJECTIVEVertebral body sliding osteotomy (VBSO) is a safe, novel technique for anterior decompression in patients with multilevel cervical spondylotic myelopathy. Another advantage of VBSO may be the restoration of cervical lordosis through multilevel anterior cervical discectomy and fusion (ACDF) above and below the osteotomy level. This study aimed to evaluate the improvement and maintenance of cervical lordosis and sagittal alignment after VBSO.METHODSA total of 65 patients were included; 34 patients had undergone VBSO, and 31 had undergone anterior cervical corpectomy and fusion (ACCF). Preoperative, postoperative, and final follow-up radiographs were used to evaluate the improvements in cervical lordosis and sagittal alignment after VBSO. C0–2 lordosis, C2–7 lordosis, segmental lordosis, C2–7 sagittal vertical axis (SVA), T1 slope, thoracic kyphosis, lumbar lordosis, sacral slope, pelvic tilt, and Japanese Orthopaedic Association scores were measured. Subgroup analysis was performed between 15 patients with 1-level VBSO and 19 patients with 2-level VBSO. Patients with 1-level VBSO were compared to patients who had undergone 1-level ACCF.RESULTSC0–2 lordosis (41.3° ± 7.1°), C2–7 lordosis (7.1° ± 12.8°), segmental lordosis (3.1° ± 9.2°), and C2–7 SVA (21.5 ± 11.7 mm) showed significant improvements at the final follow-up (39.3° ± 7.2°, 13° ± 9.9°, 15.2° ± 8.5°, and 18.4 ± 7.9 mm, respectively) after VBSO (p = 0.049, p < 0.001, p < 0.001, and p = 0.038, respectively). The postoperative segmental lordosis was significantly larger in 2-level VBSO (18.8° ± 11.6°) than 1-level VBSO (10.3° ± 5.5°, p = 0.014). The final segmental lordosis was larger in the 1-level VBSO (12.5° ± 6.2°) than the 1-level ACCF (7.2° ± 7.6°, p = 0.023). Segmental lordosis increased postoperatively (p < 0.001) and was maintained until the final follow-up (p = 0.062) after VBSO. However, the postoperatively improved segmental lordosis (p < 0.001) decreased at the final follow-up (p = 0.045) after ACCF.CONCLUSIONSNot only C2–7 lordosis and segmental lordosis, but also C0–2 lordosis and C2–7 SVA improved at the final follow-up after VBSO. VBSO improves segmental cervical lordosis markedly through multiple ACDFs above and below the VBSO level, and a preserved vertebral body may provide more structural support.

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Correlation between change in graft height and change in segmental angle following central corpectomy for cervical spondylotic myelopathy

Journal of Neurosurgery Spine ◽

10.3171/spi/2008/9/8/158 ◽

2008 ◽

Vol 9 (2) ◽

pp. 158-166 ◽

Cited By ~ 11

Author(s):

Sumit Thakar ◽

Aditya Vedantam ◽

Vedantam Rajshekhar ◽

Keyword(s):

Cervical Spine ◽

Cervical Spondylotic Myelopathy ◽

Pearson Correlation ◽

Intraclass Correlation ◽

Paraspinal Muscles ◽

Angular Change ◽

Significant Linear Correlation ◽

The Mean ◽

Segmental Angle

Object This study was undertaken to examine the correlation between change in graft height and change in angulation across grafted segments (segmental angle) in patients undergoing central corpectomy (CC) with autologous bone reconstruction for cervical spondylotic myelopathy (CSM). Methods The authors performed a retrospective analysis of 70 cases in which patients with CSM underwent uninstrumented single- or multilevel CC and had evidence of osseous fusion of their grafts at follow-up. The segmental angles and heights of the grafted segments on preoperative, postoperative, and follow-up radiographs were compared. Results The mean change in graft height (± standard deviation) was −7.3 ± 3.8 mm (mean duration of follow-up 19.7 ± 5.4 months, range 13–53 months). There was a mean kyphotic change in segmental angle of −7.3 ± 3.8° (p < 0.001). In patients who had a straight or kyphotic cervical spine (28 patients) or a straight or kyphotic segment (32 patients) preoperatively, there was a significant linear correlation between changes in graft height and changes in segmental angle (Pearson correlation, r = 0.40, p = 0.03; r = 0.40, p = 0.02, respectively). Such a correlation was not seen in the patients who had a lordotic cervical spine (42 patients) or a lordotic segment (38 patients) preoperatively (Pearson correlation, r = −0.04, p = 0.81; r = 0.08, p = 0.62, respectively). The change in segmental angle did not influence improvement in Nurick grade (p = 0.8). The degree of agreement between the 2 observers was almost perfect for measurement of graft height (postoperative intraclass correlation coefficient [ICC] = 0.94, follow-up ICC = 0.90) but was significantly lower for measurement of segmental angles (postoperative ICC = 0.71, follow-up ICC = 0.67). Conclusions Among patients undergoing uninstrumented CC for CSM, there is a significant correlation between postoperative settling and kyphotic change across fused segments in those who had straight or kyphotic cervical spines or segments preoperatively but not in those who had lordotic cervical spines or segments preoperatively. A more vigorous surgical correction of the segmental kyphosis than achieved in this study might have caused the kyphotic segments to behave like the lordotic segments. Paraspinal muscles and ligaments may play a role in determining the segmental angle as graft settling in patients with lordotic spines or segments is not linearly correlated with angular change.

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CT-Guided Posterolateral Full-Endoscopic Ventral Decompression for Single-Level Cervical Spondylotic Myelopathy

January 2018 - Pain Physician ◽

10.36076/ppj.2021.24.e203-e210 ◽

2021 ◽

pp. E203-E210

Keyword(s):

Endoscopic Surgery ◽

Cervical Spondylotic Myelopathy ◽

Japanese Orthopaedic Association ◽

Clinical Results ◽

Foraminal Stenosis ◽

Ct Guided ◽

Single Level ◽

Canal Diameter ◽

The Mean

BACKGROUND: Percutaneous full-endoscopic surgery was recently developed for the treatment of cervical foraminal stenosis and posterolateral disc herniation. However, there are no studies involving endoscopic surgery to treat cervical spondylotic myelopathy (CSM). OBJECTIVES: To observe the safety, feasibility, and efficacy of posterolateral full-endoscopic ventral decompression (PLEVD) via computed tomography (CT)-guided surgery in patients with single-level CSM. STUDY DESIGN: A prospective cohort study. SETTING: The First Affiliated Hospital of Gannan Medical College. METHODS: From May 2018 to August 2019, 21 patients with single-level CSM underwent CT-guided PLEVD. The posterolateral angle was measured during surgery. The neurologic condition was evaluated via the Japanese Orthopaedic Association (JOA) score and recovery rate, and a Visual Analog Scale (VAS) was used to measure pain relief. The maximum spinal canal diameter (MSCD) was measured on pre- and postoperative CT images. RESULTS: The mean length of follow-up was 11.3 ± 5.3 months. The average posterolateral angle was 36.0° ± 5.6°. The mean VAS score of limbs significantly decreased after surgery. The mean JOA score improved during the follow-up period. Nineteen of the 21 patients achieved good or excellent outcomes, and 2 patients had fair outcomes according to the JOA score 6 months after surgery. The average MSCD was enlarged from 0.55 ± 0.15 cm preoperatively to 1.02 ± 0.18 cm postoperatively. LIMITATIONS: This study was nonrandomized and provides only preliminary clinical results for single-level CSM. CONCLUSION: Under appropriate indications, PLEVD under CT guidance is an available and safe technique for treating single-level CSM. KEY WORDS: CT-guided, posterolateral, full-endoscopic, cervical spondylotic myelopathy

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Posterior Laminectomy and Lateral Mass Screw Fixation for the Treatment of Severe Cervical Spondylotic Myelopathy

10.21203/rs.3.rs-1202516/v1 ◽

2022 ◽

Author(s):

Chuang Li ◽

Bin Wu ◽

Yongchao Wu ◽

Haitao Pan ◽

Qixin Zheng

Keyword(s):

Cervical Spine ◽

Internal Fixation ◽

Cervical Spondylotic Myelopathy ◽

Japanese Orthopaedic Association ◽

Neck Disability Index ◽

Clinical Effects ◽

Lateral Mass ◽

Lateral Mass Screw ◽

Cervical Laminectomy

Abstract Background Severe and complex cervical spondylotic myelopathy(CSM) requires surgical treatment. The common methods of posterior cervical spine surgery are laminoplasty and laminectomy with lateral mass screw internal fixation. However, the operative effect of this surgical approach is unclear owing to the complexity and severity of CSM in patients who undergo this surgical treatment.Therefore, we aimed to evaluate the clinical effects of posterior cervical laminectomy and lateral mass screw internal fixation in patients with severe and complex CSM. Methods We retrospectively analysed 60patients (48men,12women; mean age59.7 years) with severe and complex CSM who underwent posterior cervical laminectomy and lateral mass screw internal fixation from May 2013 to June 2020. Forty-eight patients underwent laminectomy and lateral mass screw internal fixation;12 patients underwent laminectomy and lateral mass screw internal fixation with 1–2 segmental laminoplasty. C-spine radiographs, computed tomography (CT) scans, and magnetic resonance imaging (MRI) were used to detect any curvature and fusion of the cervical spine, restenosis, and loose/broken internal fixation screws.Clinical efficacy was evaluated using Japanese Orthopaedic Association (JOA)scores, neck disability index(NDI), Odom’s classification, and the visual analogue scale(VAS) for pain. Results Overall effect was satisfactory at the last follow-up (average, 3.6 years [range, 6 months–6 years]), with no restenosis or loosened, slipped, or broken internal fixations. The anterior curvature angle of lordosis (n=46)was not significantly different from baseline at the last follow-up(P>0.05). The cervical kyphosis angle (n=14)was significantly improved at the last follow-up compared with the baseline value (P<0.05), as were the JOA, NDI, and VAS scores(all P<0.05). Odom’s classifications at the last follow-up were excellent, good, and fair in 45, 12, and three patients, respectively. Conclusions Posterior cervical laminectomy and lateral mass screw internal fixation achieved satisfactory clinical results in severe and complex CSM cases.Combining this surgical method with laminoplasty of 1–2 spinal segments stabilised the cervical spine and provided spinal decompression while preventing excessive backward drift of the cervical spinal cord, resulting in fewer complications.

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Outcomes of 2-level posterior lumbar interbody fusion for 2-level degenerative lumbar spondylolisthesis

Journal of Neurosurgery Spine ◽

10.3171/2013.4.spine12651 ◽

2013 ◽

Vol 19 (1) ◽

pp. 90-94 ◽

Cited By ~ 18

Author(s):

Hironobu Sakaura ◽

Tomoya Yamashita ◽

Toshitada Miwa ◽

Kenji Ohzono ◽

Tetsuo Ohwada

Keyword(s):

Lumbar Spine ◽

Clinical Outcome ◽

Interbody Fusion ◽

Sagittal Alignment ◽

Posterior Lumbar Interbody Fusion ◽

Adjacent Segment ◽

Lumbar Interbody Fusion ◽

Single Level ◽

The Mean

Object A systematic review concerning surgical management of lumbar degenerative spondylolisthesis (DS) showed that a satisfactory clinical outcome was significantly more likely with adjunctive spinal fusion than with decompression alone. However, the role of adjunctive fusion and the optimal type of fusion remain controversial. Therefore, operative management for multilevel DS raises more complicated issues. The purpose of this retrospective study was to elucidate clinical and radiological outcomes after 2-level PLIF for 2-level DS with the least bias in determination of operative procedure. Methods Since 2005, all patients surgically treated for lumbar DS at the authors' hospital have been treated using posterior lumbar interbody fusion (PLIF) with pedicle screws, irrespective of severity of slippage, patient age, or bone quality. The authors conducted a retrospective review of 20 consecutive cases involving patients who underwent 2-level PLIF for 2-level DS and had been followed up for 2 years or longer (2-level PLIF group). They also analyzed data from 92 consecutive cases involving patients who underwent single-level PLIF for single-level DS during the same time period and had been followed for at least 2 years (1-level PLIF group). This second group served as a control. Clinical status was assessed using the Japanese Orthopaedic Association (JOA) score. Fusion status and sagittal alignment of the lumbar spine were assessed by comparing serial plain radiographs. Surgery-related complications and the need for additional surgery were evaluated. Results The mean JOA score improved significantly from 12.8 points before surgery to 20.4 points at the latest follow-up in the 2-level PLIF group (mean recovery rate 51.8%), and from 14.2 points preoperatively to 22.5 points at the latest follow-up in the single-level PLIF group (mean recovery rate 55.3%). At the final follow-up, 95.0% of patients in the 2-level PLIF group and 96.7% of those in the 1-level PLIF group had achieved solid spinal fusion, and the mean sagittal alignment of the lumbar spine was more lordotic than before surgery in both groups. Early surgery-related complications, including transient neurological complications, occurred in 6 patients in the 2-level PLIF group (30.0%) and 11 patients in the 1-level PLIF group (12.0%). Symptomatic adjacent-segment disease was found in 4 patients in the 2-level PLIF group (20.0%) and 10 patients in the 1-level PLIF group (10.9%). Conclusions The clinical outcome of 2-level PLIF for 2-level lumbar DS was satisfactory, although surgery-related complications including symptomatic adjacent-segment disease were not negligible.

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Usefulness of anterior column release for segmental lordosis restoration in degenerative lumbar kyphosis

Journal of Neurosurgery Spine ◽

10.3171/2021.5.spine202196 ◽

2021 ◽

pp. 1-7

Author(s):

Jin-Sung Park ◽

Chong-Suh Lee ◽

Youn-Taek Choi ◽

Se-Jun Park

Keyword(s):

Sagittal Alignment ◽

Adult Spinal Deformity ◽

Anterior Column ◽

Sacral Slope ◽

High Morbidity ◽

Global Sagittal Alignment ◽

The Mean ◽

Lumbar Kyphosis ◽

Segmental Lordosis

OBJECTIVE Three-column osteotomies (3COs) for surgical correction of lumbar kyphosis show a strong correction capacity, but this procedure carries high morbidity rates. The anterior column release (ACR) technique was developed as a less invasive procedure. In this study the authors aimed to evaluate sagittal alignment restoration using ACR and to determine factors that affect the degree of correction. METHODS This study included 36 patients (68 cases) who underwent ACR of more than one level for adult spinal deformity. Parameters for regional sagittal alignment included segmental lordosis (SL). The parameters for global sagittal alignment included pelvic incidence, lumbar lordosis, sacral slope, pelvic tilt, and sagittal vertical axis (SVA). In addition, the interdiscal height (IDH) and difference of interdiscal angle (DIDA) were measured to evaluate the stiffness of the vertebra segment. The changes in SL were evaluated after ACR and the change of global sagittal alignment was also determined. Factors such as the location of the ACR level, IDH, DIDA, cage height, and additional posterior column osteotomy (PCO) were analyzed for correlation with the degree of SL correction. RESULTS Thirty-six patients were included in this study. A total of 68 levels were operated with the ACR (8 levels at L2–3, 27 levels at L3–4, and 33 levels at L4–5). ACR was performed for 1 level in 10 patients, 2 levels in 20, and 3 levels in 6 patients (mean 1.9 ± 0.7 levels per patient). Mean follow-up duration was 27.1 ± 4.2 months. The mean SL of the total segment was 0.4° ± 7.2° preoperatively and increased by 15.3° ± 5.5° at the last follow-up (p < 0.001); thus, the mean increase of SL was 14.9° ± 8.1° per one ACR. Global sagittal alignment was also improved following SL restoration with SVA from 101.9 mm to 31.4 mm. The degree of SL correction was correlated with the location of ACR level (p = 0.041) and was not correlated with IDH, DIDA, cage height and additional PCO. CONCLUSIONS This study demonstrated that the mean correction angle of SL was 14.9 per one ACR. The degree of disc space collapse and stiffness of segment did not affect the degree of correction by ACR.

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