A comparative study on surgical management of long-course symptomatic cervical OPLL between anterior en bloc resection and posterior laminectomy with fusion

A comparative study on surgical management of long-course symptomatic cervical OPLL between anterior en bloc resection and posterior laminectomy with fusion | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article A comparative study on surgical management of long-course symptomatic cervical OPLL between anterior en bloc resection and posterior laminectomy with fusion Kefu Chen, Yiwei Lu, Xingcheng Dong, Tianwen Ye This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7481643/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 03 Mar, 2026 Read the published version in BMC Musculoskeletal Disorders → Version 1 posted 10 You are reading this latest preprint version Abstract Background context: There is a lack of research specifically comparing the efficacy of anterior cervical ossified posterior longitudinal ligament (OPLL) en bloc resection (ACOE) with posterior laminectomy with fusion (PLF) in patients with long course (≥ 24 months) cervical OPLL. Purpose To compare ACOE vs. PLF for management of patients with long-course cervical OPLL. Study design: A retrospective case-control study. Patient sample: Included in this study were 112 patients with long-course OPLL in our center between January 2012 and August 2021 with a mean age of 59.11 years. Of them, 64 patients (39 males and 25 females; mean age 58.14 years) were underwent ACOE, and the remaining 48 patients (43 males and 5 females; mean age 60.40 years) were underwent PLF. Outcome measures: Demographic information, OPLL index, canal occupying ratio (COR), neck Visual Analogue Scale (VAS) pain score, Japanese Orthopedic Association (JOA) score and JOA recovery rate (JOA-RR) were collected and analyzed. Methods All patients were followed up for 48 months postoperatively, during which neurological and radiological outcomes were compared between the two groups. Results The mean operative time and intraoperative blood loss in ACOE group was significantly shorter and less than those in PLF group. The mean final JOA score and JOA-RR (%) in ACOE group were significantly higher than those in PLF group. There was no significant difference in the mean final VAS score and complication rate between the two groups. Conclusions Both ACOE and PLF were effective in improving neurological function in patients with long-course OPLL. However, ACOE offered shorter operative time and less intraoperative blood loss, and better neurological recovery, especially in patients with COR ≥ 50% and K-line negativity. There was no significant difference in the incidence of complications between the two groups. PLF may be preferable to patients with long-segment OPLL. Figures Figure 1 Figure 2 Introduction Ossification of the posterior longitudinal ligament (OPLL) of the cervical spine is a heterotopic ossified degenerative disease which may cause compression of the spinal cord and/or nerves, leading to neurological dysfunction. [ 1 – 4 ] Epidemiological studies have shown a generally higher prevalence of cervical OPLL in Asians than that in Caucasians. [ 1 , 5 , 6 ] Most patients with early cervical OPLL have no specific clinical symptoms. [ 7 , 8 ] But cervical OPLL is a progressive pathological process and often leads to a variety of symptoms in late stages.[ 3 ] Surgical treatment for cervical OPLL patients with myelopathic symptoms can improve neurological functions remarkably. [ 6 ] Anterior cervical ossified posterior longitudinal ligament en bloc resection (ACOE) and posterior laminectomy with fusion (PLF) are two most common operative modalities for the treatment of OPLL. [ 9 , 10 ] Patients with a short preoperative course tend to have better surgical outcomes. [ 11 ] Although some previous studies have compared the surgical outcomes of anterior and posterior procedures for cervical OPLL, [ 7 , 9 ] they rarely discussed the choice of surgical methods for OPLL patients with long-course symptoms. Therefore, it is uncertain which operative modality is more effective in improving postoperative neurological function in patients with long-course OPLL (≥ 24 months between the onset of clinical manifestations and application of surgical intervention). The aim of the present study was to compare the therapeutic efficacy of ACOE versus PLF for the management of long-course (the interval from the first appearance of OPLL-related clinical manifestations to surgical intervention ≥ 24 months) cervical OPLL. Materials and Methods This study was approved by the Ethics Committee of XXX Hospital (XXX, XXX). Initially included in this study were 161 patients with long-course OPLL who underwent surgical treatment with ACOE or PLF in our center between January 2012 and August 2021. After excluding patients with significant thoracic cord compression, incomplete clinical data impacting the analysis, who received non-surgical treatment or were lost to follow-up, 112 patients were finally included for analysis (Fig. 1 ). All the included patients were followed up for 48 months postoperatively on the outpatient basis. Main outcomes were determined from the outpatient follow-up records. Demographic information including age, gender, body mass index (BMI), and other variables including the segment of ossification, follow-up duration, Japanese Orthopedic Association (JOA) score and Visual Analogue Scale (VAS) pain score of the neck were analyzed and compared. The preoperative radiological data, including the classification of OPLL, K-line, OPLL index (OP-index) and the canal occupying ratio (COR), are shown in Table 2 . Table 2 Radiological data. Characteristics ACOE (n = 64) PLF (n = 48) p value K-line, n (%) 1.000 a - 20(31.25) 15(31.25) + 44(68.75) 33(68.75) Classification, n (%) - Localized 27(42.19) 5(10.42) Segmental 18(28.13) 7(14.58) Continuous 13(20.31) 15(31.25) Mixed 6(9.38) 21(43.75) Mean COR, % (SD) 48.33(± 13.83) 53.87(± 14.74) 0.044 b Subgroup of COR, n (%) ≥50% 32(50.00) 33(68.75) 0.047 a <50% 32(50.00) 15(31.25) Mean OP-index, (SD) 2.17(± 1.49) 5.40(± 3.10) < 0.001 b Grade of OP-index, n (%) Grade 1 (≤ 5) 61(95.31) 26(54.17) Grade 2 (6–9) 3(4.69) 15(31.25) Grade 3 (≥ 10) 0(0) 7(14.58) a Chi square test. b Independent-samples t-test. ACOE = anterior cervical ossified posterior longitudinal ligament en bloc resection, COR = canal occupying ratio, OP-index = ossification of the posterior longitudinal ligament index. The K-line is defined as the line connecting the midpoints of the C2 and C7 spinal canal on a neutral x-ray lateral view of the cervical spine. The K-line(-) is OPLL exceeds this line, and the K-line (+) is OPLL does not exceed this line. [ 12 ] The total number of vertebrae and disc levels involved in OPLL were quantitated by OP-index. [ 13 ] The presence of OPLL in the posterior part of each disc or vertebral body was recorded as 1; the higher the OP-index, the more widespread the ossification. According to the cervical OP-index, [ 14 ] the patients were divided into three subgroups: Grade 1 (cervical OP-index ≤ 5), Grade 2 (cervical OP-index 6–9), and Grade 3 (cervical OP-index ≥ 10). Neurological function was assessed by the JOA score and JOA recovery rate (JOA-RR) as the primary indexes. JOA-RR was calculated using the following formula: JOA-RR (%) = (Post JOA – Pre JOA)/ (17 – Pre JOA) ×100%. [ 15 ] JOA-RR ≥ 75% was defined as excellent; 50–74% as good; 25–49% as fair; <25% as poor. [ 16 ] The secondary indicators were VAS neck pain score, operative time, intraoperative blood loss, and perioperative complications. The VAS score was measured on a 0–10 scale, with 0 indicating no pain, and 10 indicating the worst pain. Surgical procedures The patients in ACOE group were treated with OPLL anterior en bloc resection. [ 9 ] After laying the patient in a supine position and successful induction of general anesthesia, a transverse incision was made through the right side of the anterior cervical region to reveal the vertebral body/intervertebral disc ventrally and posteriorly. After removing the intervertebral disc and vertebral body for decompression, OPLL was excised en bloc using a high-speed burr in combination with the vertebral plate biting forceps. The cervical spine was reconstructed using the titanium mesh and/or cage and internally fixed with the titanium plate and screw system. The levels of decompression and fusion were determined based on preoperative imaging and neurological manifestations. The patients in PLF group received laminectomy with internal fixation and fusion. [ 9 ] After laying the patient in a prone position and successful induction of general anesthesia, a median incision was made in the posterior aspect of the neck to reveal the spinous processes, vertebral plates and articular synovial joints posteriorly. Total laminectomy of C3-6 was routinely performed, and the lower half of C2 lamina and/or the upper half of C7 lamina were removed in some patients. Side block screws were applied to C3 to C6. If fixation of C2 and C7 was required, pedicle screw fixation was applied without compression forces applied across the screws/rods. The cervical spine was protected with a neck collar for 3 months after both procedures. Statistical analysis Counting data are expressed as frequency, and measurement data are expressed as the mean ± standard deviation (SD). The chi-square test or Fisher's exact test was used for counting data, and the unpaired t-test was used for measurement data. Differences with a P-value of less than 0.05 were considered statistically significant. All statistical analyses of data were performed by R software (version 4.3.3; the R Foundation for Statistical Computing). Results Of the 112 patients included in this study, 82 were male and 30 were female with a mean age of 59.11 ± 11.86 years. There was no significant difference in the mean course of the disease between ACOE and PLF groups (p = 0.807). There was no significant difference in the mean age (p = 0.321) and mean length of hospital stay (p = 0.066) between the two groups. The proportion of female patients in ACOE group was significantly higher than that in PLF group (p = 0.001). BMI in ACOE group was lower than that in PLF group (p = 0.033) (Table 1 ). Table 1 Basic characterization of the patients. Characteristics ACOE (n = 64) PLF (n = 48) p value Age, y ( SD ) 58.14(± 12.07) 60.40(± 11.56) 0.321 a Female/Male, n 25/39 5/43 0.001 b Mean Course, m ( SD ) 66.94(± 75.74) 70.25(± 63.83) 0.807 a Mean BMI, kg/m 2 ( SD ) 25.07(± 2.71) 26.35(± 3.60) 0.033 a Mean Duration in Hospital, d ( SD ) 7.20(± 1.99) 8.06(± 2.90) 0.066 a History of Injury Related with Cervical, n (%) 3(4.69) 1(2.08) 0.634 c a Independent-samples t-test. b Chi square test. c Fisher’s exact test. ACOE = anterior cervical ossified posterior longitudinal ligament en bloc resection, PLF = posterior laminectomy with fusion, BMI = body mass index, CHD = coronary atherosclerotic heart disease. Radiological characteristics The distribution of ossification cases in different segments in ACOE and PLF groups is shown in Fig. 2 . There was no significant difference in the proportion of K-line negative patients between ACOE and PLF groups (31.25 vs. 31.25, p = 1.000). The mean COR in ACOE group was significantly lower than that in PLF group (48.33% vs. 53.87%, p = 0.044). The mean OP-index in ACOE group was significantly lower than that in PLF group (2.17 vs. 5.40, p < 0.001). Both ACOE and PLF were indicated for K-line negative patients, with ACOE mainly used in patients with lower COR and smaller OP-index (Table 2 ). Clinical outcomes of surgical treatment. There was no significant difference in the mean pre- and postoperative VAS scores between the two groups (4.00 vs. 3.42, p = 0.058; 1.56 vs. 1.54, p = 0.922), though the amplitude of reduction in the postoperative VAS score in ACOE group was significantly greater than that in PLF group (2.44 vs. 1.88, p = 0.025). The mean operative time and intraoperative blood loss in ACOE group were both less than those in PLF group (124.02 min vs. 197.38 min; 160.55 mL vs. 376.04 mL, both p < 0.001) (Table 3 ). Table 3 Surgical outcomes. ACOE (n = 64) PLF (n = 48) p value Levels of surgery (SD) 2.61(± 0.61) 4.33(± 0.60) < 0.001 a JOA score Mean preoperative JOA (SD) 10.64(± 2.68) 9.98(± 3.19) 0.236 a Mean final JOA (SD) 14.78(± 1.66) 13.19(± 2.00) < 0.001 a Mean JOA RR (%) 61.71(± 28.49) 42.62(± 20.60) < 0.001 a JOA RR outcome, n (excellent/good/fair/poor) 21/27/10/6 3/22/16/7 VAS score Mean preoperative VAS (SD) 4.00(± 1.51) 3.42(± 1.70) 0.058 a Mean final VAS (SD) 1.56(± 1.07) 1.54(± 1.17) 0.922 a Mean decreased of VAS (SD) 2.44(± 1.37) 1.88(± 1.20) 0.025 a Mean Time of Surgery (min) 124.02(± 37.87) 197.38(± 71.50) < 0.001 a Mean Blood Loss (mL) 160.55(± 153.12) 376.04(± 320.57) < 0.001 a a Independent-samples t-test. ACOE = anterior cervical ossified posterior longitudinal ligament en bloc resection, PLF = posterior laminectomy with fusion, JOA = Japanese Orthopedic Association, RR = recovery rate, VAS = visual analogue scale. The mean number of surgically fixated segments in ACOE was significantly smaller than that in PLF group (2.61 vs. 4.33, p < 0.001). There was no significant difference in the mean preoperative JOA score between the two groups (10.64 vs. 9.98, p = 0.236). Both final follow-up JOA score and JOA-RR were significantly higher in ACOE group than those in PLF group (14.78 vs. 13.19; 61.71% vs. 42.62%, both p < 0.001). The percentage of cases with excellent and good postoperative JOA-RR in ACOE group was higher than that in PLF group (75.00% vs. 52.08%, p = 0.012) (Table 3 ). Stratifying the two groups by whether the COR exceeded 50% and by K-line, all postoperative JOA scores in ACOE group were significantly higher than those in PLF group (both p < 0.05). There was no significant difference in JOA-RR between the two groups for cases with COR < 50% (61.37% vs. 45.97%, p = 0.064). JOA-RR in ACOE patients with COR ≥ 50% was significantly higher than that in PLF patients (62.04 vs. 41.10, p = 0.001) (Table 4 ). There was no significant difference in postoperative complication rates between ACOE and PLF groups (28.13% vs. 14.58%, p = 0.089) (Table 5 ). Table 4 Surgical outcomes stratified by COR and K-line. Characteristics Preoperative JOA score, (SD) Postoperative JOA score, (SD) JOA recovery rate, % (SD) COR < 50% ACOE (n = 32) 10.69(± 2.61) 14.66(± 1.81) 61.37(± 28.88) PLF (n = 15) 10.13(± 3.16) 13.27(± 2.37) 45.97(± 17.86) p value a 0.529 a 0.032 a 0.064 a COR ≥ 50% ACOE (n = 32) 10.59(± 2.79) 14.91(± 1.51) 62.04(± 28.56) PLF (n = 33) 9.91(± 3.25) 13.15(± 1.86) 41.10(± 21.82) p value a 0.367 a < 0.001 a 0.001 a K-line (+) ACOE (n = 44) 10.61(± 2.72) 14.57(± 1.73) 59.70(± 27.94) PLF (n = 33) 10.33(± 3.22) 13.45(± 2.17) 44.32 (± 21.04) p value a 0.680 a 0.014 a 0.010 a K-line (-) ACOE (n = 20) 10.70(± 2.66) 15.25(± 1.41) 66.12(± 29.91) PLF (n = 15) 9.20(± 3.10) 12.60(± 1.50) 38.88(± 19.79) p value a 0.133 a < 0.001 a 0.002 a a Independent-samples t-test. JOA = Japanese Orthopedic Association, ACOE = anterior cervical ossified posterior longitudinal ligament en bloc resection, PLF = posterior laminectomy with fusion, COR = canal occupying ratio. Table 5 Complications. ACOE (n = 64) PLF (n = 48) p value Total, n (%) 18(28.13) 7(14.58) 0.089 a CSF Leakage 13(20.31) 4(8.33) 0.878 b C5 Palsy 1(1.56) 3(6.25) 0.419 b Hoarseness 1(1.56) 0 > 0.999 b IF Dislodgement or Subsidence 2(3.13) 0 0.649 b Dysphagia 1(1.56) 0 > 0.999 b Pseudarthrosis 0 0 - Reoperation 0 0 - a Chi square test. b Fisher exact test. ACOE = anterior cervical ossified posterior longitudinal ligament en bloc resection, PLF = posterior laminectomy with fusion, CSF = cerebrospinal fluid, IF = internal fixation. Discussion The progression of cervical OPLL may exacerbate invasive damage to the spinal cord and/or nerve roots, which in turn can cause a variety of symptoms. [ 3 ] Surgical treatment can improve nerve damage in cervical OPLL patients with progressive myelopathy, [ 10 ] but there are still controversies over choice of the anterior or posterior surgical approach, knowing that both have respective advantages and disadvantages. [ 6 ] , [ 17 ] As anterior surgery allows for direct decompression of the anterior spinal cord, it can theoretically prevent further progression of the ossification and reduce the likelihood of recompression of the spinal cord due to OPLL. [ 9 ] The anterior cervical approach is generally considered preferable for neurological recovery. [ 5 ] In addition, the posterior approach is relatively less technically demanding, but postoperative neurological recovery is not as good as that with anterior cervical surgery because the ossified material is not removed in posterior surgery. [ 9 , 18 ] Furthermore, long-term follow-up observations in some studies demonstrated that patients undergoing posterior surgery had reduced neurological function and may even require second-stage anterior surgery. [ 19 ] Similarly, a prospective comparative study from our center also demonstrated that anterior surgery was superior to posterior surgery for neurological recovery, especially in OPLL patients with high spinal canal occupancy. [ 9 ] Compared to patients with a shorter course of disease, patients with a longer course of disease tended to have poorer outcomes. [ 20 , 21 ] However, no studies have discussed which surgical procedure is more appropriate for cervical OPLL with a course longer than 24 months. The present study demonstrated that the final follow-up JOA score and JOA-RR in patients with long-course OPLL in ACOE group were significantly higher than those in PLF group. The number of patients with excellent or good JOA-RR was also higher in ACOE group. Our subgroup analysis further confirmed that the final follow-up JOA score and JOA-RR in ACOE group were significantly higher than those in PLF group in patients with COR ≥ 50% or K-line negativity, indicating that neurological recovery after ACOE was significantly better than that after PLF in patients with long-course OPLL (≥ 24 months), and suggesting that posterior surgery may be associated with risk of suboptimal decompression in patients with high COR. [ 22 ] The main reason is that ACOE allows for direct decompression of the compressed spinal cord/nerves. Therefore, ACOE is preferable for patients with a long course of OPLL, especially those with localized ossification and segmental types and those with low OP-index values. A long-continuous shape OPLL extending upward from the C3 or C4 vertebrae to the posterior aspect of the C2 vertebrae is the typical morphology of a continuous OPLL. In this form of OPLL with compression, it is difficult to completely resect it by ACOE, so it is also more suitable for posterior surgery. [ 16 ] It is critical to carefully consider the advantages and disadvantages of each surgical procedure for the sake of making an appropriate choice that can better benefit patients with OPLL. The study by Yoshii et al. [ 7 ] showed that postoperative pain was significantly higher after posterior surgery than that after ACOE. Postoperative axial neck pain is mainly due to paraspinal muscle injury after posterior surgery. With remarkable advances in surgical techniques, axial symptoms associated with this type of muscle damage has been reduced markedly. [ 23 ] However, posterior internal fixation placement requires widespread separation of the paravertebral muscles, particularly the posterior staple-rod system. In addition, the scope of posterior surgical fixation is relatively large, and C2-7 Cobb angle change may also lead to a lesser reduction in cervical axial pain after posterior surgery as compared with ACOE. [ 24 ] The results of this study also demonstrated that ACOE offered a relatively lower incidence of axial pain after long-course cervical OPLL than PLF. In contrast to Yoshii et al. [ 10 ] who reported that anterior surgery consumed longer operative time, our study showed that the mean operative time for ACOE in patients with long-course cervical OPLL was significantly shorter than that for PLF, and the mean intraoperative blood loss in ACOE group was also significantly less than that in PLF group. It is probably because the ACOE procedure is less invasive, with shorter surgical exposure time, no need for extensive intraoperative isolation of the paravertebral muscles at multiple segments, and no extensive invasion of the muscles which shortens the hemostasis time because of less exudation and bleeding. In addition, we used a high-speed burr to resect the en bloc cervical OPLL to enhance the surgical efficacy, which is also an important factor contributing to the above-mentioned advantages. Our findings are similar with the results of the randomized controlled trial by Cao et al. [ 9 ] Previous studies have shown that anterior cervical surgery for cervical OPLL is associated with a higher complication rate as compared with posterior cervical surgery. [ 10 ] Our study demonstrated that the incidence of postoperative complications was similar between the anterior and posterior procedures for long-course cervical OPLL, though the overall complication rate for ACOE is slightly higher than that of anterior surgery reported in the literature (28.13% vs. 21.8%) [ 25 ]. Our study demonstrated that cerebrospinal fluid (CSF) leakage was the most common complication in ACOE group, accounting for about 20.31%, which is similar with that reported in the literature for anterior cervical surgery (6.5%-30.8%) [ 17 , 18 , 26 ], and is slightly higher than 8.33% in PLF group. This is considered mainly due to adhesion of about 13–15% of OPLL to the dural sac and dural sac lesions during intraoperative removal of the ossified mass. [ 27 , 28 ]. All cases of CSF leakage recovered after application of an artificial dura and postoperative compression bandage, and no intraspinal infection, meningitis, respiratory obstruction, cutaneous CSF leakage [ 29 ] or secondary surgery occurred in any case. Dysphagia and airway problems are common in ACOE. Dysphagia is mainly attributable to edema of the retropharyngeal tissues caused by constriction of the esophagus or protrusion of the titanium plate during ACOE. Risk factors for persistent dysphagia and airway problems have been reported to include age, prolonged surgery time, multi-segmental surgery and smoking. [ 24 , 30 ] Treatment for dysphagia requires extra medical costs. In our study, the incidence of dysphagia in ACOE group was not significantly higher than that in PLF group, which may be because we avoided compressing the prevertebral fascia under the titanium plate when placing the plate, and that we did not overstretch the esophagus intraoperatively. However, PLF surgery is recommended for patients who already have dysphagia. Airway obstruction is a life-threatening complication which sometimes requires reintubation. It is therefore important to minimize these complications during anterior surgery. In elderly patients and other high-risk patients with smoking or respiratory comorbidities, PLF should be considered to avoid these complications. [ 10 ] Internal fixation dislodgement or subsidence occurred in two cases of ACOE group, but as both patients had no neurological symptoms, they were followed up closely after discharge, and no re-operation was required for them. The following limitations exist in this study. This is a retrospective observational study comparing the postoperative clinical outcomes of ACOE and PLF for the treatment of long-course OPLL and therefore bias in the selection of surgical methods could not be avoided. Large multi-center prospective randomized trials are required to eliminate such potential bias, though randomized choice of surgical methods for spinal surgery is ethically challenging. [ 7 ] Despite these limitations, we believe that this study of long-duration cervical OPLL surgery provides a valuable reference for surgeons in their choice of surgical approaches for cervical OPLL. Conclusions Both ACOE and PLF are effective in improving neurological function in patients with long-duration cervical OPLL with no statistically significant difference in the incidence of complications. However, ACOE is preferable for neurological recovery, especially for patients with COR ≥ 50% and K-line negativity. PLF could be considered for the treatment of patients with long-segment OPLL. There was no significant difference in the incidence of complications between the two groups. Therefore, surgeons need to be aware of the advantages and disadvantages of both approaches when making decisions on the surgical approach for cervical OPLL. Declarations Ethics approval and Consent to Participate: The study protocol was established, according to the ethical guidelines of the Helsinki Declaration and was approved by the Ethics Committee of Changzheng Hospital (Shanghai, China). Consent to Participate declaration: Written informed consent was obtained from individual or guardian participants. Funding: This study without Funding. Clinical trial number: not applicable. Competing Interests: The authors declare that they have no competing interests. Authors' Contribution: K.C. and Y.L. wrote the main manuscript text and prepared interpretation of data. X.D. and T.Y. gave the conception and designed work. K.C. and Y.L. contributed equally to this work, as co-first authors. X.D. and T.Y. is the co-correspondence. All authors reviewed the manuscript. 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Perioperative factors associated with favorable outcomes of posterior decompression and instrumented fusion for cervical ossification of the posterior longitudinal ligament: A retrospective multicenter study. J Clin Neurosci. 2018;57:74–8. Li H, Dai LY. A systematic review of complications in cervical spine surgery for ossification of the posterior longitudinal ligament. Spine J. 2011;11:1049–57. Kimura A, Seichi A, Hoshino Y, et al. Perioperative complications of anterior cervical decompression with fusion in patients with ossification of the posterior longitudinal ligament: a retrospective, multi-institutional study. J Orthop Sci. 2012;17:667–72. Mizuno J, Nakagawa H, Matsuo N, et al. Dural ossification associated with cervical ossification of the posterior longitudinal ligament: frequency of dural ossification and comparison of neuroimaging modalities in ability to identify the disease. J Neurosurg Spine. 2005;2:425–30. Belanger TA, Roh JS, Hanks SE, et al. Ossification of the posterior longitudinal ligament. Results of anterior cervical decompression and arthrodesis in sixty-one North American patients. J Bone Joint Surg Am. 2005;87:610–5. Mitchell BD, Verla T, Reddy D, et al. Reliable Intraoperative Repair Nuances of Cerebrospinal Fluid Leak in Anterior Cervical Spine Surgery and Review of the Literature. World Neurosurg. 2016;88:252–9. Chen Y, Guo Y, Chen D, et al. Long-term outcome of laminectomy and instrumented fusion for cervical ossification of the posterior longitudinal ligament. Int Orthop. 2009;33:1075–80. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 03 Mar, 2026 Read the published version in BMC Musculoskeletal Disorders → Version 1 posted Editorial decision: Revision requested 10 Oct, 2025 Reviews received at journal 27 Sep, 2025 Reviews received at journal 25 Sep, 2025 Reviewers agreed at journal 06 Sep, 2025 Reviewers agreed at journal 05 Sep, 2025 Reviewers invited by journal 05 Sep, 2025 Editor assigned by journal 05 Sep, 2025 Editor invited by journal 05 Sep, 2025 Submission checks completed at journal 04 Sep, 2025 First submitted to journal 04 Sep, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7481643","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":511093963,"identity":"d3474196-30b2-46bd-aefa-75adab274d89","order_by":0,"name":"Kefu Chen","email":"","orcid":"","institution":"Shanghai Changhai Hospital","correspondingAuthor":false,"prefix":"","firstName":"Kefu","middleName":"","lastName":"Chen","suffix":""},{"id":511093964,"identity":"bec824f8-22a4-4ce9-8203-ecca049f6453","order_by":1,"name":"Yiwei Lu","email":"","orcid":"","institution":"Shanghai Changzheng Hospital","correspondingAuthor":false,"prefix":"","firstName":"Yiwei","middleName":"","lastName":"Lu","suffix":""},{"id":511093965,"identity":"15f1df2c-4ee9-4e79-afa3-92a6c24afa3a","order_by":2,"name":"Xingcheng Dong","email":"","orcid":"","institution":"The Fourth Affiliated Hospital of Soochow University","correspondingAuthor":false,"prefix":"","firstName":"Xingcheng","middleName":"","lastName":"Dong","suffix":""},{"id":511093970,"identity":"d95afca5-933a-4c63-9d51-fc79dad76c05","order_by":3,"name":"Tianwen Ye","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA5ElEQVRIiWNgGAWjYJCCAxCKsYHhg4GNHBEamBFaGGcUpBkTpQXB5PlwOJGgBoPj/QcP/NxxWM5cIrntsY0BcwID++GjG/BqOXOY4WDvmcPGljMS241zDNjyGHjS0m7g1XIjmeEAb9vtxA1nDrZJ5xjwFDNI8Jjh13L/McPBv22368FaLAwkEhsIarnBzHAYaEuCwfHGNmkGAwPCWiTPJBsclm37b7jheGO7YY9BgjEbIb/wHT/4+OPbtjR5g8Pszx78+PNfjp/98DG8WhQOINhsSCQeIN+ArmUUjIJRMApGAToAAEcZUVFrX6IRAAAAAElFTkSuQmCC","orcid":"","institution":"Shanghai Changzheng Hospital","correspondingAuthor":true,"prefix":"","firstName":"Tianwen","middleName":"","lastName":"Ye","suffix":""}],"badges":[],"createdAt":"2025-08-28 15:23:08","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7481643/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7481643/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12891-026-09661-9","type":"published","date":"2026-03-03T15:59:52+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":91486427,"identity":"17220914-625d-4b0b-b606-ce5d5a18ef43","added_by":"auto","created_at":"2025-09-17 04:57:07","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":179413,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eParticipants of the study.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"Onlinefloatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-7481643/v1/f2a7b21ec9fc85b41e522f77.png"},{"id":91489255,"identity":"04917b35-3511-418f-ab4b-eabaaab5a94d","added_by":"auto","created_at":"2025-09-17 05:13:07","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":101504,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eCases of OPLL by cervical level in different groups.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"Onlinefloatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-7481643/v1/3c2c8ad2d3223286263c62de.png"},{"id":104251501,"identity":"3c4dfdda-d837-44e3-8399-9d0226a0d222","added_by":"auto","created_at":"2026-03-09 16:13:35","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1079459,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7481643/v1/8409d1af-8d4a-41fa-ab88-dbc21ddaf020.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"A comparative study on surgical management of long-course symptomatic cervical OPLL between anterior en bloc resection and posterior laminectomy with fusion","fulltext":[{"header":"Introduction","content":"\u003cp\u003eOssification of the posterior longitudinal ligament (OPLL) of the cervical spine is a heterotopic ossified degenerative disease which may cause compression of the spinal cord and/or nerves, leading to neurological dysfunction. [\u003cspan additionalcitationids=\"CR2 CR3\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e] Epidemiological studies have shown a generally higher prevalence of cervical OPLL in Asians than that in Caucasians. [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] Most patients with early cervical OPLL have no specific clinical symptoms. [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e] But cervical OPLL is a progressive pathological process and often leads to a variety of symptoms in late stages.[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e] Surgical treatment for cervical OPLL patients with myelopathic symptoms can improve neurological functions remarkably. [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]\u003c/p\u003e\u003cp\u003eAnterior cervical ossified posterior longitudinal ligament en bloc resection (ACOE) and posterior laminectomy with fusion (PLF) are two most common operative modalities for the treatment of OPLL. [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e] Patients with a short preoperative course tend to have better surgical outcomes. [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e] Although some previous studies have compared the surgical outcomes of anterior and posterior procedures for cervical OPLL, [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] they rarely discussed the choice of surgical methods for OPLL patients with long-course symptoms. Therefore, it is uncertain which operative modality is more effective in improving postoperative neurological function in patients with long-course OPLL (\u0026ge;\u0026thinsp;24 months between the onset of clinical manifestations and application of surgical intervention). The aim of the present study was to compare the therapeutic efficacy of ACOE \u003cem\u003eversus\u003c/em\u003e PLF for the management of long-course (the interval from the first appearance of OPLL-related clinical manifestations to surgical intervention\u0026thinsp;\u0026ge;\u0026thinsp;24 months) cervical OPLL.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cp\u003e This study was approved by the Ethics Committee of XXX Hospital (XXX, XXX). Initially included in this study were 161 patients with long-course OPLL who underwent surgical treatment with ACOE or PLF in our center between January 2012 and August 2021.\u003c/p\u003e\u003cp\u003eAfter excluding patients with significant thoracic cord compression, incomplete clinical data impacting the analysis, who received non-surgical treatment or were lost to follow-up, 112 patients were finally included for analysis (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). All the included patients were followed up for 48 months postoperatively on the outpatient basis. Main outcomes were determined from the outpatient follow-up records.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eDemographic information including age, gender, body mass index (BMI), and other variables including the segment of ossification, follow-up duration, Japanese Orthopedic Association (JOA) score and Visual Analogue Scale (VAS) pain score of the neck were analyzed and compared.\u003c/p\u003e\u003cp\u003eThe preoperative radiological data, including the classification of OPLL, K-line, OPLL index (OP-index) and the canal occupying ratio (COR), are shown in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eRadiological data.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCharacteristics\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eACOE (n\u0026thinsp;=\u0026thinsp;64)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePLF (n\u0026thinsp;=\u0026thinsp;48)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003ep value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eK-line, n (%)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.000 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e20(31.25)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e15(31.25)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e+\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e44(68.75)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e33(68.75)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eClassification, n (%)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLocalized\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e27(42.19)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e5(10.42)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSegmental\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e18(28.13)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e7(14.58)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eContinuous\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e13(20.31)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e15(31.25)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMixed\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e6(9.38)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e21(43.75)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eMean COR, % (SD)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e48.33(\u0026plusmn;\u0026thinsp;13.83)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e53.87(\u0026plusmn;\u0026thinsp;14.74)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.044 \u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eSubgroup of COR, n (%)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u0026ge;50%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e32(50.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e33(68.75)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.047 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u0026lt;50%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e32(50.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e15(31.25)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eMean OP-index, (SD)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2.17(\u0026plusmn;\u0026thinsp;1.49)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e5.40(\u0026plusmn;\u0026thinsp;3.10)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001 \u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eGrade of OP-index, n (%)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGrade 1 (\u0026le;\u0026thinsp;5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e61(95.31)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e26(54.17)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGrade 2 (6\u0026ndash;9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3(4.69)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e15(31.25)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGrade 3 (\u0026ge;\u0026thinsp;10)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0(0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e7(14.58)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003e\u003csup\u003ea\u003c/sup\u003e Chi square test. \u003csup\u003eb\u003c/sup\u003e Independent-samples t-test. ACOE\u0026thinsp;=\u0026thinsp;anterior cervical ossified posterior longitudinal ligament en bloc resection, COR\u0026thinsp;=\u0026thinsp;canal occupying ratio, OP-index\u0026thinsp;=\u0026thinsp;ossification of the posterior longitudinal ligament index.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eThe K-line is defined as the line connecting the midpoints of the C2 and C7 spinal canal on a neutral x-ray lateral view of the cervical spine. The K-line(-) is OPLL exceeds this line, and the K-line (+) is OPLL does not exceed this line. [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]\u003c/p\u003e\u003cp\u003eThe total number of vertebrae and disc levels involved in OPLL were quantitated by OP-index. [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e] The presence of OPLL in the posterior part of each disc or vertebral body was recorded as 1; the higher the OP-index, the more widespread the ossification. According to the cervical OP-index, [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e] the patients were divided into three subgroups: Grade 1 (cervical OP-index\u0026thinsp;\u0026le;\u0026thinsp;5), Grade 2 (cervical OP-index 6\u0026ndash;9), and Grade 3 (cervical OP-index\u0026thinsp;\u0026ge;\u0026thinsp;10).\u003c/p\u003e\u003cp\u003eNeurological function was assessed by the JOA score and JOA recovery rate (JOA-RR) as the primary indexes. JOA-RR was calculated using the following formula: JOA-RR (%) = (Post JOA \u0026ndash; Pre JOA)/ (17 \u0026ndash; Pre JOA) \u0026times;100%. [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e] JOA-RR\u0026thinsp;\u0026ge;\u0026thinsp;75% was defined as excellent; 50\u0026ndash;74% as good; 25\u0026ndash;49% as fair; \u0026lt;25% as poor. [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]\u003c/p\u003e\u003cp\u003eThe secondary indicators were VAS neck pain score, operative time, intraoperative blood loss, and perioperative complications. The VAS score was measured on a 0\u0026ndash;10 scale, with 0 indicating no pain, and 10 indicating the worst pain.\u003c/p\u003e\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eSurgical procedures\u003c/h2\u003e\u003cp\u003eThe patients in ACOE group were treated with OPLL anterior en bloc resection. [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] After laying the patient in a supine position and successful induction of general anesthesia, a transverse incision was made through the right side of the anterior cervical region to reveal the vertebral body/intervertebral disc ventrally and posteriorly. After removing the intervertebral disc and vertebral body for decompression, OPLL was excised en bloc using a high-speed burr in combination with the vertebral plate biting forceps. The cervical spine was reconstructed using the titanium mesh and/or cage and internally fixed with the titanium plate and screw system. The levels of decompression and fusion were determined based on preoperative imaging and neurological manifestations.\u003c/p\u003e\u003cp\u003eThe patients in PLF group received laminectomy with internal fixation and fusion. [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] After laying the patient in a prone position and successful induction of general anesthesia, a median incision was made in the posterior aspect of the neck to reveal the spinous processes, vertebral plates and articular synovial joints posteriorly. Total laminectomy of C3-6 was routinely performed, and the lower half of C2 lamina and/or the upper half of C7 lamina were removed in some patients. Side block screws were applied to C3 to C6. If fixation of C2 and C7 was required, pedicle screw fixation was applied without compression forces applied across the screws/rods. The cervical spine was protected with a neck collar for 3 months after both procedures.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\u003ch2\u003eStatistical analysis\u003c/h2\u003e\u003cp\u003eCounting data are expressed as frequency, and measurement data are expressed as the mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (SD). The chi-square test or Fisher's exact test was used for counting data, and the unpaired t-test was used for measurement data. Differences with a P-value of less than 0.05 were considered statistically significant. All statistical analyses of data were performed by R software (version 4.3.3; the R Foundation for Statistical Computing).\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eOf the 112 patients included in this study, 82 were male and 30 were female with a mean age of 59.11\u0026thinsp;\u0026plusmn;\u0026thinsp;11.86 years. There was no significant difference in the mean course of the disease between ACOE and PLF groups (p\u0026thinsp;=\u0026thinsp;0.807). There was no significant difference in the mean age (p\u0026thinsp;=\u0026thinsp;0.321) and mean length of hospital stay (p\u0026thinsp;=\u0026thinsp;0.066) between the two groups. The proportion of female patients in ACOE group was significantly higher than that in PLF group (p\u0026thinsp;=\u0026thinsp;0.001). BMI in ACOE group was lower than that in PLF group (p\u0026thinsp;=\u0026thinsp;0.033) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eBasic characterization of the patients.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCharacteristics\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eACOE (n\u0026thinsp;=\u0026thinsp;64)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePLF (n\u0026thinsp;=\u0026thinsp;48)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003ep value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAge, y (\u003cem\u003eSD\u003c/em\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e58.14(\u0026plusmn;\u0026thinsp;12.07)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e60.40(\u0026plusmn;\u0026thinsp;11.56)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.321 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFemale/Male, n\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e25/39\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5/43\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.001 \u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMean Course, m (\u003cem\u003eSD\u003c/em\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e66.94(\u0026plusmn;\u0026thinsp;75.74)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e70.25(\u0026plusmn;\u0026thinsp;63.83)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.807 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMean BMI, kg/m\u003csup\u003e2\u003c/sup\u003e (\u003cem\u003eSD\u003c/em\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e25.07(\u0026plusmn;\u0026thinsp;2.71)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e26.35(\u0026plusmn;\u0026thinsp;3.60)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.033 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMean Duration in Hospital, d (\u003cem\u003eSD\u003c/em\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e7.20(\u0026plusmn;\u0026thinsp;1.99)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e8.06(\u0026plusmn;\u0026thinsp;2.90)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.066 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHistory of Injury Related with Cervical, n (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3(4.69)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1(2.08)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.634 \u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003e\u003csup\u003ea\u003c/sup\u003e Independent-samples t-test. \u003csup\u003eb\u003c/sup\u003e Chi square test. \u003csup\u003ec\u003c/sup\u003e Fisher\u0026rsquo;s exact test. ACOE\u0026thinsp;=\u0026thinsp;anterior cervical ossified posterior longitudinal ligament en bloc resection, PLF\u0026thinsp;=\u0026thinsp;posterior laminectomy with fusion, BMI\u0026thinsp;=\u0026thinsp;body mass index, CHD\u0026thinsp;=\u0026thinsp;coronary atherosclerotic heart disease.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\n\u003ch3\u003eRadiological characteristics\u003c/h3\u003e\n\u003cp\u003eThe distribution of ossification cases in different segments in ACOE and PLF groups is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. There was no significant difference in the proportion of K-line negative patients between ACOE and PLF groups (31.25 \u003cem\u003evs.\u003c/em\u003e 31.25, p\u0026thinsp;=\u0026thinsp;1.000). The mean COR in ACOE group was significantly lower than that in PLF group (48.33% \u003cem\u003evs.\u003c/em\u003e 53.87%, p\u0026thinsp;=\u0026thinsp;0.044). The mean OP-index in ACOE group was significantly lower than that in PLF group (2.17 \u003cem\u003evs.\u003c/em\u003e 5.40, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Both ACOE and PLF were indicated for K-line negative patients, with ACOE mainly used in patients with lower COR and smaller OP-index (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eClinical outcomes of surgical treatment.\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThere was no significant difference in the mean pre- and postoperative VAS scores between the two groups (4.00 \u003cem\u003evs.\u003c/em\u003e 3.42, p\u0026thinsp;=\u0026thinsp;0.058; 1.56 \u003cem\u003evs.\u003c/em\u003e 1.54, p\u0026thinsp;=\u0026thinsp;0.922), though the amplitude of reduction in the postoperative VAS score in ACOE group was significantly greater than that in PLF group (2.44 \u003cem\u003evs.\u003c/em\u003e 1.88, p\u0026thinsp;=\u0026thinsp;0.025). The mean operative time and intraoperative blood loss in ACOE group were both less than those in PLF group (124.02 min \u003cem\u003evs.\u003c/em\u003e 197.38 min; 160.55 mL \u003cem\u003evs.\u003c/em\u003e 376.04 mL, both p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eSurgical outcomes.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eACOE (n\u0026thinsp;=\u0026thinsp;64)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePLF (n\u0026thinsp;=\u0026thinsp;48)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003ep value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eLevels of surgery (SD)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2.61(\u0026plusmn;\u0026thinsp;0.61)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4.33(\u0026plusmn;\u0026thinsp;0.60)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eJOA score\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMean preoperative JOA (SD)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e10.64(\u0026plusmn;\u0026thinsp;2.68)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e9.98(\u0026plusmn;\u0026thinsp;3.19)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.236 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMean final JOA (SD)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e14.78(\u0026plusmn;\u0026thinsp;1.66)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e13.19(\u0026plusmn;\u0026thinsp;2.00)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMean JOA RR (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e61.71(\u0026plusmn;\u0026thinsp;28.49)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e42.62(\u0026plusmn;\u0026thinsp;20.60)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eJOA RR outcome, n\u003c/b\u003e (excellent/good/fair/poor)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e21/27/10/6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3/22/16/7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eVAS score\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMean preoperative VAS (SD)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4.00(\u0026plusmn;\u0026thinsp;1.51)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3.42(\u0026plusmn;\u0026thinsp;1.70)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.058 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMean final VAS (SD)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.56(\u0026plusmn;\u0026thinsp;1.07)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.54(\u0026plusmn;\u0026thinsp;1.17)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.922 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMean decreased of VAS (SD)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2.44(\u0026plusmn;\u0026thinsp;1.37)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.88(\u0026plusmn;\u0026thinsp;1.20)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.025 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eMean Time of Surgery (min)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e124.02(\u0026plusmn;\u0026thinsp;37.87)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e197.38(\u0026plusmn;\u0026thinsp;71.50)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eMean Blood Loss (mL)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e160.55(\u0026plusmn;\u0026thinsp;153.12)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e376.04(\u0026plusmn;\u0026thinsp;320.57)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003e\u003csup\u003ea\u003c/sup\u003e Independent-samples t-test. ACOE\u0026thinsp;=\u0026thinsp;anterior cervical ossified posterior longitudinal ligament en bloc resection, PLF\u0026thinsp;=\u0026thinsp;posterior laminectomy with fusion, JOA\u0026thinsp;=\u0026thinsp;Japanese Orthopedic Association, RR\u0026thinsp;=\u0026thinsp;recovery rate, VAS\u0026thinsp;=\u0026thinsp;visual analogue scale.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eThe mean number of surgically fixated segments in ACOE was significantly smaller than that in PLF group (2.61 \u003cem\u003evs.\u003c/em\u003e 4.33, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). There was no significant difference in the mean preoperative JOA score between the two groups (10.64 \u003cem\u003evs.\u003c/em\u003e 9.98, p\u0026thinsp;=\u0026thinsp;0.236). Both final follow-up JOA score and JOA-RR were significantly higher in ACOE group than those in PLF group (14.78 \u003cem\u003evs.\u003c/em\u003e 13.19; 61.71% \u003cem\u003evs.\u003c/em\u003e 42.62%, both p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). The percentage of cases with excellent and good postoperative JOA-RR in ACOE group was higher than that in PLF group (75.00% \u003cem\u003evs.\u003c/em\u003e 52.08%, p\u0026thinsp;=\u0026thinsp;0.012) (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eStratifying the two groups by whether the COR exceeded 50% and by K-line, all postoperative JOA scores in ACOE group were significantly higher than those in PLF group (both p\u0026thinsp;\u0026lt;\u0026thinsp;0.05). There was no significant difference in JOA-RR between the two groups for cases with COR\u0026thinsp;\u0026lt;\u0026thinsp;50% (61.37% vs. 45.97%, p\u0026thinsp;=\u0026thinsp;0.064). JOA-RR in ACOE patients with COR\u0026thinsp;\u0026ge;\u0026thinsp;50% was significantly higher than that in PLF patients (62.04 vs. 41.10, p\u0026thinsp;=\u0026thinsp;0.001) (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). There was no significant difference in postoperative complication rates between ACOE and PLF groups (28.13% vs. 14.58%, p\u0026thinsp;=\u0026thinsp;0.089) (Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eSurgical outcomes stratified by COR and K-line.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCharacteristics\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003ePreoperative JOA score, (SD)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePostoperative JOA score, (SD)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eJOA recovery rate, % (SD)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCOR\u0026thinsp;\u0026lt;\u0026thinsp;50%\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eACOE (n\u0026thinsp;=\u0026thinsp;32)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e10.69(\u0026plusmn;\u0026thinsp;2.61)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e14.66(\u0026plusmn;\u0026thinsp;1.81)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e61.37(\u0026plusmn;\u0026thinsp;28.88)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePLF (n\u0026thinsp;=\u0026thinsp;15)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e10.13(\u0026plusmn;\u0026thinsp;3.16)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e13.27(\u0026plusmn;\u0026thinsp;2.37)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e45.97(\u0026plusmn;\u0026thinsp;17.86)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ep value \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.529 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.032 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.064 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eCOR\u0026thinsp;\u0026ge;\u0026thinsp;50%\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eACOE (n\u0026thinsp;=\u0026thinsp;32)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e10.59(\u0026plusmn;\u0026thinsp;2.79)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e14.91(\u0026plusmn;\u0026thinsp;1.51)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e62.04(\u0026plusmn;\u0026thinsp;28.56)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePLF (n\u0026thinsp;=\u0026thinsp;33)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e9.91(\u0026plusmn;\u0026thinsp;3.25)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e13.15(\u0026plusmn;\u0026thinsp;1.86)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e41.10(\u0026plusmn;\u0026thinsp;21.82)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ep value \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.367 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.001 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eK-line (+)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eACOE (n\u0026thinsp;=\u0026thinsp;44)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e10.61(\u0026plusmn;\u0026thinsp;2.72)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e14.57(\u0026plusmn;\u0026thinsp;1.73)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e59.70(\u0026plusmn;\u0026thinsp;27.94)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePLF (n\u0026thinsp;=\u0026thinsp;33)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e10.33(\u0026plusmn;\u0026thinsp;3.22)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e13.45(\u0026plusmn;\u0026thinsp;2.17)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e44.32 (\u0026plusmn;\u0026thinsp;21.04)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ep value \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.680 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.014 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.010 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eK-line (-)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eACOE (n\u0026thinsp;=\u0026thinsp;20)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e10.70(\u0026plusmn;\u0026thinsp;2.66)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e15.25(\u0026plusmn;\u0026thinsp;1.41)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e66.12(\u0026plusmn;\u0026thinsp;29.91)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePLF (n\u0026thinsp;=\u0026thinsp;15)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e9.20(\u0026plusmn;\u0026thinsp;3.10)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e12.60(\u0026plusmn;\u0026thinsp;1.50)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e38.88(\u0026plusmn;\u0026thinsp;19.79)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ep value \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.133 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.002 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003e\u003csup\u003ea\u003c/sup\u003e Independent-samples t-test. JOA\u0026thinsp;=\u0026thinsp;Japanese Orthopedic Association, ACOE\u0026thinsp;=\u0026thinsp;anterior cervical ossified posterior longitudinal ligament en bloc resection, PLF\u0026thinsp;=\u0026thinsp;posterior laminectomy with fusion, COR\u0026thinsp;=\u0026thinsp;canal occupying ratio.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eComplications.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eACOE (n\u0026thinsp;=\u0026thinsp;64)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePLF (n\u0026thinsp;=\u0026thinsp;48)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003ep value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eTotal, n (%)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e18(28.13)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e7(14.58)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.089 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCSF Leakage\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e13(20.31)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4(8.33)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.878 \u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eC5 Palsy\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1(1.56)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3(6.25)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.419 \u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHoarseness\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1(1.56)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026gt;\u0026thinsp;0.999 \u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIF Dislodgement or Subsidence\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2(3.13)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.649 \u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDysphagia\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1(1.56)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026gt;\u0026thinsp;0.999 \u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePseudarthrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eReoperation\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003e\u003csup\u003ea\u003c/sup\u003e Chi square test. \u003csup\u003eb\u003c/sup\u003e Fisher exact test. ACOE\u0026thinsp;=\u0026thinsp;anterior cervical ossified posterior longitudinal ligament en bloc resection, PLF\u0026thinsp;=\u0026thinsp;posterior laminectomy with fusion, CSF\u0026thinsp;=\u0026thinsp;cerebrospinal fluid, IF\u0026thinsp;=\u0026thinsp;internal fixation.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe progression of cervical OPLL may exacerbate invasive damage to the spinal cord and/or nerve roots, which in turn can cause a variety of symptoms. [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e] Surgical treatment can improve nerve damage in cervical OPLL patients with progressive myelopathy, [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e] but there are still controversies over choice of the anterior or posterior surgical approach, knowing that both have respective advantages and disadvantages. [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]\u003csup\u003e,\u003c/sup\u003e [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e] As anterior surgery allows for direct decompression of the anterior spinal cord, it can theoretically prevent further progression of the ossification and reduce the likelihood of recompression of the spinal cord due to OPLL. [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] The anterior cervical approach is generally considered preferable for neurological recovery. [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e] In addition, the posterior approach is relatively less technically demanding, but postoperative neurological recovery is not as good as that with anterior cervical surgery because the ossified material is not removed in posterior surgery. [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e] Furthermore, long-term follow-up observations in some studies demonstrated that patients undergoing posterior surgery had reduced neurological function and may even require second-stage anterior surgery. [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e] Similarly, a prospective comparative study from our center also demonstrated that anterior surgery was superior to posterior surgery for neurological recovery, especially in OPLL patients with high spinal canal occupancy. [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] Compared to patients with a shorter course of disease, patients with a longer course of disease tended to have poorer outcomes. [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e] However, no studies have discussed which surgical procedure is more appropriate for cervical OPLL with a course longer than 24 months.\u003c/p\u003e\u003cp\u003eThe present study demonstrated that the final follow-up JOA score and JOA-RR in patients with long-course OPLL in ACOE group were significantly higher than those in PLF group. The number of patients with excellent or good JOA-RR was also higher in ACOE group. Our subgroup analysis further confirmed that the final follow-up JOA score and JOA-RR in ACOE group were significantly higher than those in PLF group in patients with COR\u0026thinsp;\u0026ge;\u0026thinsp;50% or K-line negativity, indicating that neurological recovery after ACOE was significantly better than that after PLF in patients with long-course OPLL (\u0026ge;\u0026thinsp;24 months), and suggesting that posterior surgery may be associated with risk of suboptimal decompression in patients with high COR. [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e] The main reason is that ACOE allows for direct decompression of the compressed spinal cord/nerves. Therefore, ACOE is preferable for patients with a long course of OPLL, especially those with localized ossification and segmental types and those with low OP-index values. A long-continuous shape OPLL extending upward from the C3 or C4 vertebrae to the posterior aspect of the C2 vertebrae is the typical morphology of a continuous OPLL. In this form of OPLL with compression, it is difficult to completely resect it by ACOE, so it is also more suitable for posterior surgery. [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e] It is critical to carefully consider the advantages and disadvantages of each surgical procedure for the sake of making an appropriate choice that can better benefit patients with OPLL.\u003c/p\u003e\u003cp\u003eThe study by Yoshii et al. [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e] showed that postoperative pain was significantly higher after posterior surgery than that after ACOE. Postoperative axial neck pain is mainly due to paraspinal muscle injury after posterior surgery. With remarkable advances in surgical techniques, axial symptoms associated with this type of muscle damage has been reduced markedly. [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e] However, posterior internal fixation placement requires widespread separation of the paravertebral muscles, particularly the posterior staple-rod system. In addition, the scope of posterior surgical fixation is relatively large, and C2-7 Cobb angle change may also lead to a lesser reduction in cervical axial pain after posterior surgery as compared with ACOE. [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e] The results of this study also demonstrated that ACOE offered a relatively lower incidence of axial pain after long-course cervical OPLL than PLF.\u003c/p\u003e\u003cp\u003eIn contrast to Yoshii et al. [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e] who reported that anterior surgery consumed longer operative time, our study showed that the mean operative time for ACOE in patients with long-course cervical OPLL was significantly shorter than that for PLF, and the mean intraoperative blood loss in ACOE group was also significantly less than that in PLF group. It is probably because the ACOE procedure is less invasive, with shorter surgical exposure time, no need for extensive intraoperative isolation of the paravertebral muscles at multiple segments, and no extensive invasion of the muscles which shortens the hemostasis time because of less exudation and bleeding. In addition, we used a high-speed burr to resect the en bloc cervical OPLL to enhance the surgical efficacy, which is also an important factor contributing to the above-mentioned advantages. Our findings are similar with the results of the randomized controlled trial by Cao et al. [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]\u003c/p\u003e\u003cp\u003ePrevious studies have shown that anterior cervical surgery for cervical OPLL is associated with a higher complication rate as compared with posterior cervical surgery. [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e] Our study demonstrated that the incidence of postoperative complications was similar between the anterior and posterior procedures for long-course cervical OPLL, though the overall complication rate for ACOE is slightly higher than that of anterior surgery reported in the literature (28.13% \u003cem\u003evs.\u003c/em\u003e 21.8%) [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. Our study demonstrated that cerebrospinal fluid (CSF) leakage was the most common complication in ACOE group, accounting for about 20.31%, which is similar with that reported in the literature for anterior cervical surgery (6.5%-30.8%) [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e], and is slightly higher than 8.33% in PLF group. This is considered mainly due to adhesion of about 13\u0026ndash;15% of OPLL to the dural sac and dural sac lesions during intraoperative removal of the ossified mass. [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. All cases of CSF leakage recovered after application of an artificial dura and postoperative compression bandage, and no intraspinal infection, meningitis, respiratory obstruction, cutaneous CSF leakage [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e] or secondary surgery occurred in any case. Dysphagia and airway problems are common in ACOE. Dysphagia is mainly attributable to edema of the retropharyngeal tissues caused by constriction of the esophagus or protrusion of the titanium plate during ACOE. Risk factors for persistent dysphagia and airway problems have been reported to include age, prolonged surgery time, multi-segmental surgery and smoking. [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e] Treatment for dysphagia requires extra medical costs. In our study, the incidence of dysphagia in ACOE group was not significantly higher than that in PLF group, which may be because we avoided compressing the prevertebral fascia under the titanium plate when placing the plate, and that we did not overstretch the esophagus intraoperatively. However, PLF surgery is recommended for patients who already have dysphagia. Airway obstruction is a life-threatening complication which sometimes requires reintubation. It is therefore important to minimize these complications during anterior surgery. In elderly patients and other high-risk patients with smoking or respiratory comorbidities, PLF should be considered to avoid these complications. [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e] Internal fixation dislodgement or subsidence occurred in two cases of ACOE group, but as both patients had no neurological symptoms, they were followed up closely after discharge, and no re-operation was required for them.\u003c/p\u003e\u003cp\u003eThe following limitations exist in this study. This is a retrospective observational study comparing the postoperative clinical outcomes of ACOE and PLF for the treatment of long-course OPLL and therefore bias in the selection of surgical methods could not be avoided. Large multi-center prospective randomized trials are required to eliminate such potential bias, though randomized choice of surgical methods for spinal surgery is ethically challenging. [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e] Despite these limitations, we believe that this study of long-duration cervical OPLL surgery provides a valuable reference for surgeons in their choice of surgical approaches for cervical OPLL.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eBoth ACOE and PLF are effective in improving neurological function in patients with long-duration cervical OPLL with no statistically significant difference in the incidence of complications. However, ACOE is preferable for neurological recovery, especially for patients with COR\u0026thinsp;\u0026ge;\u0026thinsp;50% and K-line negativity. PLF could be considered for the treatment of patients with long-segment OPLL. There was no significant difference in the incidence of complications between the two groups. Therefore, surgeons need to be aware of the advantages and disadvantages of both approaches when making decisions on the surgical approach for cervical OPLL.\u003c/p\u003e"},{"header":"Declarations","content":"\u003col\u003e\n \u003cli\u003eEthics approval and Consent to Participate: The study protocol was established, according to the ethical guidelines of the Helsinki Declaration and was approved by the Ethics Committee of Changzheng Hospital (Shanghai, China).\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eConsent to Participate declaration: Written informed consent was obtained from individual or guardian participants.\u003c/li\u003e\n \u003cli\u003eFunding: This study without Funding.\u003c/li\u003e\n \u003cli\u003eClinical trial number: not applicable.\u003c/li\u003e\n \u003cli\u003eCompeting Interests: The authors declare that they have no competing interests.\u003c/li\u003e\n \u003cli\u003eAuthors' Contribution: K.C. and Y.L. wrote the main manuscript text and prepared interpretation of data. X.D. and T.Y. gave the conception and designed work. K.C. and Y.L. contributed equally to this work, as co-first authors. X.D. and T.Y. is the co-correspondence. All authors reviewed the manuscript.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eConsent for publication: Not Applicable.\u003c/strong\u003e\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eAvailability of Data and Materials: All the raw generated and/or analyzed data in the current study are included in this published article and are available from the corresponding author on reasonable request.\u003c/strong\u003e\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eMatsunaga S, Sakou T. Ossification of the posterior longitudinal ligament of the cervical spine: etiology and natural history. Spine (Phila Pa 1976). 2012;37:E309\u0026ndash;14.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCouto AR, Parreira B, Power DM, et al. Evidence for a genetic contribution to the ossification of spinal ligaments in Ossification of Posterior Longitudinal Ligament and Diffuse idiopathic skeletal hyperostosis: A narrative review. Front Genet. 2022;13:987867.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChen T, Wang Y, Zhou H, et al. Comparison of anterior cervical discectomy and fusion versus anterior cervical corpectomy and fusion in the treatment of localized ossification of the posterior longitudinal ligament. J Orthop Surg (Hong Kong). 2023;31:10225536231167704.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBoody BS, Lendner M, Vaccaro AR. Ossification of the posterior longitudinal ligament in the cervical spine: a review. Int Orthop. 2019;43:797\u0026ndash;805.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKalb S, Martirosyan NL, Perez-Orribo L, et al. Analysis of demographics, risk factors, clinical presentation, and surgical treatment modalities for the ossified posterior longitudinal ligament. Neurosurg Focus. 2011;30:E11.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLe HV, Wick JB, Van BW, et al. Ossification of the Posterior Longitudinal Ligament: Pathophysiology, Diagnosis, and Management. J Am Acad Orthop Surg. 2022;30:820\u0026ndash;30.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYoshii T, Sakai K, Hirai T, et al. Anterior decompression with fusion versus posterior decompression with fusion for massive cervical ossification of the posterior longitudinal ligament with a\u0026thinsp;\u0026ge;\u0026thinsp;50% canal occupying ratio: a multicenter retrospective study. Spine J. 2016;16:1351\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAnshori F, Hutami WD, Tobing S. 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Spine (Phila Pa 1976). 2008;33:E990\u0026ndash;3.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKawaguchi Y, Nakano M, Yasuda T, et al. Ossification of the posterior longitudinal ligament in not only the cervical spine, but also other spinal regions: analysis using multidetector computed tomography of the whole spine. Spine (Phila Pa 1976). 2013;38:E1477\u0026ndash;82.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHirai T, Yoshii T, Iwanami A, et al. Prevalence and Distribution of Ossified Lesions in the Whole Spine of Patients with Cervical Ossification of the Posterior Longitudinal Ligament A Multicenter Study (JOSL CT study). PLoS ONE. 2016;11:e0160117.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKawaguchi Y, Nakano M, Yasuda T, et al. Anterior decompressive surgery after cervical laminoplasty in patients with ossification of the posterior longitudinal ligament. Spine J. 2014;14:955\u0026ndash;63.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eFujimori T, Iwasaki M, Okuda S, et al. Long-term results of cervical myelopathy due to ossification of the posterior longitudinal ligament with an occupying ratio of 60% or more. Spine (Phila Pa 1976). 2014;39:58\u0026ndash;67.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhang J, Liang Q, Qin D, et al. The anterior versus posterior approach for the treatment of ossification of the posterior longitudinal ligament in the cervical spine: A systematic review and meta-analysis. J Spinal Cord Med. 2021;44:340\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eFeng F, Ruan W, Liu Z, et al. Anterior versus posterior approach for the treatment of cervical compressive myelopathy due to ossification of the posterior longitudinal ligament: A systematic review and meta-analysis. Int J Surg. 2016;27:26\u0026ndash;33.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTokuhashi Y, Ajiro Y, Umezawa N. A patient with two re-surgeries for delayed myelopathy due to progression of ossification of the posterior longitudinal ligaments after cervical laminoplasty. Spine (Phila Pa 1976). 2009;34:E101\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLi S, Zhang P, Gao X, et al. Potential risk factors for poor outcome after anterior surgery for patients with cervical ossification of the posterior longitudinal ligament. Ther Clin Risk Manag. 2018;14:341\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLi H, Jiang LS, Dai LY. A review of prognostic factors for surgical outcome of ossification of the posterior longitudinal ligament of cervical spine. Eur Spine J. 2008;17:1277\u0026ndash;88.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYamazaki A, Homma T, Uchiyama S, et al. Morphologic limitations of posterior decompression by midsagittal splitting method for myelopathy caused by ossification of the posterior longitudinal ligament in the cervical spine. Spine (Phila Pa 1976). 1999;24:32\u0026ndash;4.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSinha S, Jagetia A. Bilateral open-door expansive laminoplasty using unilateral posterior midline approach with preservation of posterior supporting elements for management of cervical myelopathy and radiculomyelopathy\u0026ndash;analysis of clinical and radiological outcome and surgical technique. Acta Neurochir (Wien). 2011;153:975\u0026ndash;84.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKatsumi K, Hirano T, Watanabe K, et al. Perioperative factors associated with favorable outcomes of posterior decompression and instrumented fusion for cervical ossification of the posterior longitudinal ligament: A retrospective multicenter study. J Clin Neurosci. 2018;57:74\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLi H, Dai LY. A systematic review of complications in cervical spine surgery for ossification of the posterior longitudinal ligament. Spine J. 2011;11:1049\u0026ndash;57.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKimura A, Seichi A, Hoshino Y, et al. Perioperative complications of anterior cervical decompression with fusion in patients with ossification of the posterior longitudinal ligament: a retrospective, multi-institutional study. J Orthop Sci. 2012;17:667\u0026ndash;72.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMizuno J, Nakagawa H, Matsuo N, et al. Dural ossification associated with cervical ossification of the posterior longitudinal ligament: frequency of dural ossification and comparison of neuroimaging modalities in ability to identify the disease. J Neurosurg Spine. 2005;2:425\u0026ndash;30.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBelanger TA, Roh JS, Hanks SE, et al. Ossification of the posterior longitudinal ligament. Results of anterior cervical decompression and arthrodesis in sixty-one North American patients. J Bone Joint Surg Am. 2005;87:610\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMitchell BD, Verla T, Reddy D, et al. Reliable Intraoperative Repair Nuances of Cerebrospinal Fluid Leak in Anterior Cervical Spine Surgery and Review of the Literature. World Neurosurg. 2016;88:252\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChen Y, Guo Y, Chen D, et al. Long-term outcome of laminectomy and instrumented fusion for cervical ossification of the posterior longitudinal ligament. Int Orthop. 2009;33:1075\u0026ndash;80.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-musculoskeletal-disorders","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bmsd","sideBox":"Learn more about [BMC Musculoskeletal Disorders](http://bmcmusculoskeletdisord.biomedcentral.com/)","snPcode":"","submissionUrl":"https://author-welcome.nature.com/12891","title":"BMC Musculoskeletal Disorders","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-7481643/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7481643/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground context:\u003c/h2\u003e\u003cp\u003eThere is a lack of research specifically comparing the efficacy of anterior cervical ossified posterior longitudinal ligament (OPLL) en bloc resection (ACOE) with posterior laminectomy with fusion (PLF) in patients with long course (\u0026ge;\u0026thinsp;24 months) cervical OPLL.\u003c/p\u003e\u003ch2\u003ePurpose\u003c/h2\u003e\u003cp\u003eTo compare ACOE \u003cem\u003evs.\u003c/em\u003e PLF for management of patients with long-course cervical OPLL.\u003c/p\u003e\u003ch2\u003eStudy design:\u003c/h2\u003e\u003cp\u003eA retrospective case-control study.\u003c/p\u003e\u003ch2\u003ePatient sample:\u003c/h2\u003e\u003cp\u003eIncluded in this study were 112 patients with long-course OPLL in our center between January 2012 and August 2021 with a mean age of 59.11 years. Of them, 64 patients (39 males and 25 females; mean age 58.14 years) were underwent ACOE, and the remaining 48 patients (43 males and 5 females; mean age 60.40 years) were underwent PLF.\u003c/p\u003e\u003ch2\u003eOutcome measures:\u003c/h2\u003e\u003cp\u003eDemographic information, OPLL index, canal occupying ratio (COR), neck Visual Analogue Scale (VAS) pain score, Japanese Orthopedic Association (JOA) score and JOA recovery rate (JOA-RR) were collected and analyzed.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e\u003cp\u003eAll patients were followed up for 48 months postoperatively, during which neurological and radiological outcomes were compared between the two groups.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eThe mean operative time and intraoperative blood loss in ACOE group was significantly shorter and less than those in PLF group. The mean final JOA score and JOA-RR (%) in ACOE group were significantly higher than those in PLF group. There was no significant difference in the mean final VAS score and complication rate between the two groups.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e\u003cp\u003eBoth ACOE and PLF were effective in improving neurological function in patients with long-course OPLL. However, ACOE offered shorter operative time and less intraoperative blood loss, and better neurological recovery, especially in patients with COR\u0026thinsp;\u0026ge;\u0026thinsp;50% and K-line negativity. There was no significant difference in the incidence of complications between the two groups. PLF may be preferable to patients with long-segment OPLL.\u003c/p\u003e","manuscriptTitle":"A comparative study on surgical management of long-course symptomatic cervical OPLL between anterior en bloc resection and posterior laminectomy with fusion","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-17 04:57:02","doi":"10.21203/rs.3.rs-7481643/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-10-10T05:49:30+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-09-27T13:48:40+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-09-25T13:47:24+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"73882469069455282771632725844547053587","date":"2025-09-06T07:46:09+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"214496860605641731272092042924849332447","date":"2025-09-06T03:09:32+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-09-06T02:34:11+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-09-06T02:24:25+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-09-05T17:13:19+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-09-04T06:17:16+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Musculoskeletal Disorders","date":"2025-09-04T06:13:40+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-musculoskeletal-disorders","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bmsd","sideBox":"Learn more about [BMC Musculoskeletal Disorders](http://bmcmusculoskeletdisord.biomedcentral.com/)","snPcode":"","submissionUrl":"https://author-welcome.nature.com/12891","title":"BMC Musculoskeletal Disorders","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"506634f5-f4ce-4123-ac0e-263f96b07676","owner":[],"postedDate":"September 17th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-03-09T16:09:21+00:00","versionOfRecord":{"articleIdentity":"rs-7481643","link":"https://doi.org/10.1186/s12891-026-09661-9","journal":{"identity":"bmc-musculoskeletal-disorders","isVorOnly":false,"title":"BMC Musculoskeletal Disorders"},"publishedOn":"2026-03-03 15:59:52","publishedOnDateReadable":"March 3rd, 2026"},"versionCreatedAt":"2025-09-17 04:57:02","video":"","vorDoi":"10.1186/s12891-026-09661-9","vorDoiUrl":"https://doi.org/10.1186/s12891-026-09661-9","workflowStages":[]},"version":"v1","identity":"rs-7481643","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7481643","identity":"rs-7481643","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}