A novel surgical technique for the treatment of continuous-type ossification of the posterior longitudinal ligament with K-line negative

A novel surgical technique for the treatment of continuous-type ossification of the posterior longitudinal ligament with K-line negative | 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 novel surgical technique for the treatment of continuous-type ossification of the posterior longitudinal ligament with K-line negative Shuang Zhang, Haozhi Yang, Guoqiang Liu, Yuyue Chen, Rencai Ma, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7140591/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Objective To investigate a novel surgical technique for the treatment of patients with continuous-type cervical ossification of the posterior longitudinal ligament (OPLL) with K-line negative using anterior hinge-like osteotomy through ossification and antedisplacement of the vertebral-ossification compound, combined with posterior single open-door laminoplasty. Methods Four patients with continuous-type cervical ossification of the posterior longitudinal ligament (OPLL), showing straight and stiff cervical alignment without lordosis, and identified as K-line negative, underwent a novel surgical procedure. Initially, posterior single open-door laminoplasty was performed in combination with lower facet V-shaped osteotomy and lateral mass joint release. Subsequently, an osteotomy was conducted through the ossification ligament using a hinge-like technique, along with anterior displacing and pulling using pre-bent plates and screws, to restore cervical lordosis. The duration of surgery, amount of blood loss, and the following parameters were assessed using radiography, CT scans, and MRI: cervical lordosis, spinal canal enlargement, and medullary decompression. Pain levels were measured using the Visual Analog Scale (VAS), while disability was evaluated using the Neck Disability Index (NDI) and Japan Orthopedic Association (JOA) scores, both before and after surgery. Results The surgery was successful, with an average operation time of 240 ±38 minutes and a bleeding volume of 400 ± 50ml. Postoperative images revealed a significant enlargement of the cervical spinal canal, improved cervical lordosis compared to preoperative measurements, and resolved compression of the spinal cord. The postoperative patients experienced a significant improvement in their clinical symptoms, as evidenced by improved VAS, NDI, and JOA scores. This indicates that the novel surgery effectively provided sufficient decompression. Conclusions The novel technique of anterior hinge-like osteotomy through ossification and antedisplacement of the vertebral-ossification compound, combined with posterior single open-door laminoplasty, has demonstrated the ability to restore cervical lordosis and enhance the outcomes of single posterior laminoplasty in the treatment of cervical OPLL with negative K-line. This innovative approach offers a new and promising solution for treating complex cases of cervical OPLL. OPLL (ossification of the posterior longitudinal ligament) anterior hinge-like osteotomy and cervical lordosis reconstruction (HOLR) single open-door laminoplasty K-line Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Introduction Cervical ossification of posterior longitudinal ligament (OPLL) refers to a multifactorial disease characterized by ectopic bone hypertrophy, ossification and hyperplasia of the posterior longitudinal ligament, resulting in spinal stenosis, compression of the cervical spinal cord, and associated spinal nerve damage [ 1 – 4 ] . Its ossifications continue to grow, ultimately leading limb sensation, movement disorders, as well as dysfunction of the visceral autonomic nervous system [ 5 ] . The ossified posterior longitudinal ligament of the cervical spine is located anterior to the spinal canal. Conservative methods, such as medication and physical therapy, may provide temporary relief of symptoms but do not address the underlying issue of spinal cord compression caused by cervical OPLL. The surgical treatment of cervical OPLL involves decompression of the spinal cord and stabilization of the spine. Various surgical techniques can be used depending on the characteristics of the OPLL, such as the location, extent, and stiffness of the ossification. Due to the complexity of the condition of cervical OPLL, long-term chronic compression can lead to adhesions between ossification and the dura, often complicating direct anterior decompression. Currently, the predominant surgical approach for cervical spinal canal stenosis involves posterior enlargement and decompression, primarily utilizing laminoplasty [ 6 – 11 ] . The surgical principle is to expand the cervical spinal canal and bring the spinal cord to drift backwards avoiding compression from the front of the spinal cord and achieving effective decompression. Compared to the direct anterior decompression [ 12 ] , the posterior laminoplasty was considered a relatively simpler and safer approach for treating most cases of cervical OPLL, achieving favorable therapeutic outcomes. However, it is mainly suitable for cervical OPLL patients with positive K-line or normal cervical lordosis. For cervical OPLL patients with poor cervical lordosis or negative K-line, ever after posterior laminectomy decompression is performed, the spinal cord is still difficult to effectively drift backward to avoid anterior compression and achieve the ideal therapeutic effect. It is well known that cervical OPLL patients with continuous type ossification of the posterior longitudinal ligament and straight stiff cervical spine are difficult to treat. To treat cervical OPLL patient with negative K-line, we have chosen the anterior approach to perform direct decompression with such as ACAF technique [ 22 – 24 ] . Besides, we can directly fully or partially remove ossifications with so called floating technique [ 12 , 15 ] . Actually, the latter technique is safer and more feasible for treating OPLL with adhesion between ossification and dura. The principle of ACAF surgery is to separate the cervical vertebral ossification complex as a whole form the surrounding tissues and move it forward as a whole, in order to relieve anterior compression of the cervical spinal cord and expand the volume of the vertebral canal. This technique involves controllable anterior displacement of the cervical vertebral ossification complex (VOC) as a whole, thereby increasing the vertebral canal volume and relieving anterior compression of the cervical spinal cord, without requiring direct removal of ossification During the surgical procedures, creating narrow bone grooves on both sides of the ossification boundary to separate the vertebral ossification complex from the surrounding structure was a critical step. It is crucial to accurately determine the exact boundaries of ossification and perform proper anatomical dissection. However, there are risks of venous plexus bleeding, dural tear and cerebrospinal fluid (CSF) leakage. Additionally, when the spinal canal on both sides is extremely narrow, there is still a potential risk of nerve root and spinal cord damage. A more convenient and safer technique was designed to address the issue of spinal cord compression in patients with poor cervical lordosis and continuous-type cervical OPLL. We propose an innovative approach that involves utilizing anterior hinge-like osteotomy through ossification and ante-displacement of the vertebral-ossification compound, combined with posterior single open-door laminoplasty(illustrated in Fig. 4 ), to treat continuous-type cervical OPLL with K-line negative. Methods Patient Population In this study, four patients with continuous-type cervical OPLL, as confirmed by CT and radiography, were found to have cervical kyphosis without lordosis and were recognized as K-line negative. All patients presented with symptoms associated with cervical myelopathy caused by spinal cord compression. Preoperative MRI of the cervical spine revealed cervical spinal stenosis with anterior compression of the spinal cord by the ossification (Fig. 1 f). Cervical lateral radiograph showed that the midpoint of the C2 spinal canal was connected to the midpoint of the C7 spinal canal (Fig. 2 ), indicating that the highest point of ossification of the posterior longitudinal ligament exceeded the K-line [ 13 ] . Before surgery, pain levels were assessed using the Visual Analog Scale (VAS), while the degree of disability was evaluated using the Neck Disability Index (NDI) and Japan Orthopedic Association (JOA) scores. Table 1 provides an overview of the patients' general condition, main symptoms, related scores, and imaging findings. Table 1 Basic information of the 4 patients with continuous-type cervical OPLL Case Age (yrs), Sex Major Symptoms duration of symptoms (mos) C2–7 Lordosis OPLL segment No. Neutral Flexion Extension 1 57, M Numbness and fatigue in upper limbs 38 2 −16 16 C2-5 2 56, M Hand numbness 36 3 −16 21 C3–6 3 50, F Numbness and fatigue in limbs, bowel and bladder disturbances 12 −2 −19 13 C4–6 4 62, M Numbness and fatigue in upper limbs 3 −1 −26 18 C2–4 These patients underwent a novel surgical procedure involving anterior hinge-like osteotomy through the ossification and ante-displacement of the vertebra-ossification compound, combined with posterior single open-door laminoplasty. Surgical Technique The surgery was conducted under general anesthesia following completion of necessary preoperative preparations. It involved posterior single open-door laminoplasty, posterior lateral mass joint osteotomy and release, combined with anterior hinge-like osteotomy through ossification and ante-displacement of the vertebral-ossification compound with plate and screw pull force to reconstruct the cervical lordosis. The patient was positioned prone on the operating table with the head placed securely in the head frame, while maintaining cervical spine traction. The operating table was set in a head-high and foot-low position. Posterior single open-door laminoplasty was carried out using a high-speed burr, targeting the C3-C6, C2-C7, or C3-C7 levels. Subsequently, the ultrasonic osteotome was employed to resect the inferior articular processes of the cervical vertebrae (C2-C6) with a V-shaped osteotomy fashion. Lateral block joints were released to eliminate posterior resistance, allowing for hinge-like movement of the cervical spine (Fig. 3 ). After the completion of the posterior surgery, the patients underwent anterior hinge-like osteotomy through ossification and ante-displacement of the cervical vertebrae. The anterior structure of the C3 to C7 vertebral body was fully exposed and a high-speed burr was used to expand each intervertebral space appropriately, providing more space for deep operations. The intervertebral disc tissue was removed until the deep hard ossified ligament was reached. Then, an ultrasonic bone blade was used to horizontally cut off the ossified ligaments to create hinges. The operation was immediately stopped when there was a slight sense of breakthrough, indicating that the ossified ligaments had been cut through. The size of the intervertebral spaces was measured and small bone blocks, slightly thicker in the front and thinner in the back, were prepared from the patient's autologous iliac bone and implanted into the intervertebral space. the bones in front of the vertebrae were removed to increase the antedisplacement and shaping space (Fig. 4 ). A pre-bent titanium plate of appropriate length was selected first, then fix the plate to the vertebrae at both ends with screws, then gradually screw of the middle vertebral segment to pull the vertebrae ossification complex forward, and forming the cervical lordosis. After placing the drainage, the incision was sutured to complete the surgery. Results All 4 patients successfully underwent surgery and were monitored in the intensive care unit for one day to assess airway function and vital signs. The average operation time was 325.5 ± 16.5 minutes, with an average blood loss of 452.5 ± 23.5 milliliters. CSF leaking occurred in 1 patient during the osteotomy with ultrasonic osteotome at the ossification ligament. We immediately placed lumbar cistern drainage in the patient, regularly draining around 300ml of cerebrospinal fluid every day, and after 5 days, the tube was removed. The patient's cervical wound healed smoothly without any sequelae. All the 4 patients’ clinical symptoms and scores showed significant improvement. The NDI score, VAS score, and JOA score all improved in all patients (Table 2 ). Postoperative CT scans displayed a considerable enlargement of the cervical spinal canal, and the ossification of the posterior longitudinal ligament of the cervical spine had shifted forward, resulting in the formation of cervical lordosis. Postoperative lateral radiographs and CT scans confirmed that all patients transitioned from K-line negative to K-line positive (Fig. 5 d, 5 e and Fig. 6 e, 6 f, 6 g). Postoperative MRI scans demonstrated a notable increase in the size of the cervical spinal canal, improved cervical sagittal alignment, and the relieve of spinal cord compression (Fig. 5 f and Fig. 6 h). Table 2 Preoperative and postoperative NDI scores, JOA scores and VAS scores. Case NDI scores JOA scores VAS scores No. Preoperative Postoperative Preoperative Postoperative Preoperative Postoperative 1 11 6 10 15 10 6 2 12 4 12 16 12 5 3 11 7 11 15 10 3 4 13 7 11 14 9 5 Discussion Cervical OPLL patients often require surgical intervention due to the growth of ossifications that compress the spinal cord and/or nerve roots, leading to sensory and motor dysfunction in the limbs. There are two main types of surgical approaches for treating cervical OPLL: posterior surgery and anterior surgery [ 14 – 18 ] . Posterior surgeries primarily include posterior cervical laminoplasty, posterior cervical laminectomy combined with internal fixation. Anterior surgeries involve direct resection of cervical anterior ossification for decompression, or anterior controllable antedisplacement and fusion (ACAF). Although the selection of an anterior or posterior approach remains controversial, multilevel cord compression caused by ossification of the posterior longitudinal ligament (OPLL) and preoperative lordotic sagittal alignment are conditions that favor a posterior approach. However, performing posterior laminoplasty or laminectomy in patients with cervical kyphosis may result in poor clinical and radiological outcomes. In 2008, Japanese scholars [ 19 ] recognized the significant impact of the physiological lordosis of the cervical spine on the effectiveness of posterior cervical laminoplasty surgery and proposed the K-line method for assessment. The K-line refers to a line connecting the midpoint of the C2 spinal canal with the midpoint of the C7 spinal canal on the cervical lateral radiograph. K-line negative indicates that the highest point of the ossification material exceeds the K-line, suggesting a reduced physiological curvature or extensive ossification. Conversely, K-line positive suggests that the highest point of ossification is located in front of the K-line, which could imply better surgical outcomes with posterior laminoplasty. It is generally believed that OPLL patients with K-line positive achieve better therapeutic outcomes with posterior laminoplasty. This is because patients with cervical lordosis have sufficient space for the spinal cord to drift backwards, preventing compression of the ossification after vertebral canal expansion. For OPLL patients with K-line negative, characterized by reduced cervical lordosis and a rigid cervical spine, posterior cervical laminoplasty often yield less favorable outcomes. This is due to the limit ability of the spinal cord to drift posteriorly even after vertebral canal enlargement. So, it is generally recommended to perform direct anterior cervical ossification resection or ACAF technique for treatment of such patients. Direct anterior decompression surgery, involving resection of ossification compound, was a technically demanding and high-risk procedure for most spine surgeons. It is associated with a high complication rate, including dural tear, spinal cord injury, and uncontrollable venous plexus bleeding, largely due to the long-term compression and adhesion of ossification with the dural sac [ 20 – 22 ] . To address the challenges associated with direct resection of OPLL for decompression, an alternative technique known as Anterior Cervical Foraminotomy (ACAF) has been introduced in recent years. Unlike traditional methods, ACAF does not necessitate the complete dissection or direct removal of ossified structures within the vertebral canal. This approach effectively minimizes the risk of dural tear and uncontrollable venous plexus bleeding [ 24 – 26 ] . However, despite its advantages, the ACAF technique remains technically demanding and presents significant challenges for many spine surgeons. Consequently, it requires a longer learning curve for mastery. Apart from the anterior decompression for treatment OPLL with negative K line by ACAF or ACCF, another strategy for treatment of this complex disorders was reconstruction of the lordosis combined with posterior laminoplasty. Some scholars recommended the use of posterior cervical laminectomy and reconstruction of cervical lordosis through a posterior cervical pedicle screw-rod system to improve the efficacy of laminoplasty surgery [ 23 ] . This technique proved to be effective for non-continuous-types cervical OPLL patients with good cervical mobility. But for patients with continuous-types cervical OPLL with long segments and a stiff cervical spine, the posterior screw-rod system is insufficient to reshape the cervical lordosis, often resulting in poor result. To enhance the flexibility of the cervical spine in patients with continuous ossification of OPLL, we have developed a novel method that involves reconstructing cervical lordosis by cutting off the ossified band through the intervertebral space and reshaping the anterior arch using a cervical plate. This procedure, termed the “anterior hinge-like osteotomy through ossification and cervical lordosis reconstruction techs (HOLR).” Our HOLR technique combined with the posterior single open-door laminoplasty has developed to treat the continuous OPLL with negative K line. In this study, all patients initially underwent posterior laminoplasty to enlarge the cervical vertebral canal. Subsequently, cervical lordosis was reconstructed using the HOLR technique in a single stage (3 cases) or a two-stage procedure (1 case). At the follow-up, all patients demonstrated significant improvement in nerve function compared to pre-surgery. Radiographic and CT findings revealed that cervical lordosis improved from K-negative to K-positive. MRI showed a marked enlargement of the vertebral canal and a reduction in anterior compression compared to pre-surgery measurements. The principle of this novel technique is to transform a rigid structure into a flexible one by transverse cutting using an ultrasonic osteotome in the cervical gaps. Compared with the greenstick fracture technique, this technology demonstrated more effective reconstruction of cervical lordosis. During the posterior single open-door laminoplasty, V-grade osteotomy and release of lateral block joints were performed, as previously reported [ 11 ] . Our technique only requires posterior-anterior approach, which was more simplified than the posterior-anterior-posterior procedures. Theoretically, the novel technology is safer than ACAF techs, because it does not require complete dissociation of the ossification or direct removal of ossification in the vertebral canal, thus avoiding dural tear and uncontrollable venous plexus bleeding. Additionally, the antedisplacement of cervical does not cause new compression of the cervical spinal cord due to the significant enlargement of the vertebral canal diameter through posterior single open-door laminoplasty. All procedures and manipulations are controllable and safety and is readily mastered by general spinal surgeons. However, due to the limited number of cases currently being performed, the surgical shortcomings and limitations of this technology require further clinical observation. In summary, the continuous-type cervical OPLL with stiff cervical alignment and K-line negative often poses a significant challenge in clinical treatment. Simply performing posterior cervical laminoplasty often falls short of optimal results. By combining posterior cervical laminoplasty with HOLR could provide a novel way to antedisplace the cervical ossification complex safely and reconstruct the lordosis of the cervical spine. This approach effectively alleviates the anterior compression of the spinal cord and achieves a desirable decompression effect. Nevertheless, further research involving a larger number of cases is necessary to establish its generalizability and ensure its safety. Declarations Ethics approval and consent to participant This study was conducted in accordance with the principles of the Declaration of Helsinki. All participants (or their legal guardians) provided written informed consent for participation. The study protocol approved by the Local Ethics Committee of General Hospital of Southern Theatre Command. Personal identifiers were removed from the anonymized datasets to protect participant privacy. Clinical trial number Not applicable. Consent for publication All participants (or their legal guardians) provided written informed consent for the publication of identifiable data, including medical images and video. Competing interests The authors declare no completing interests. Funding Not applicable. Author Contribution Shuang Zhang: Writing–original draft, Data curation, Conceptualization. Haozhi Yang: Writing–review & editing, Supervision, Methodology. Guoqiang Liu: Writing–original draft, Software, Methodology, Data curation, Conceptualization. Yuyue Chen: Writing–review & editing, Supervision. Rencai Ma: Writing – review & editing, Supervision. Junlin Chen: Writing–review & editing, Validation, Supervision. Xiangyang Ma: Writing–review & editing, Formal analysis, Conceptualization. Jianhua Wang: Writing–review & editing, Writing–original draft, Supervision, Methodology, Investigation, Formal analysis, Data curation. Acknowledgements Not applicable. Data Availability The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request. References Nam DC, Lee HJ, Lee CJ, et al. Molecular Pathophysiology of Ossification of the Posterior Longitudinal Ligament (OPLL). Biomol Ther (Seoul). 2019;27(4):342–8. Saetia K, Cho D, Lee S, et al. Ossification of the posterior longitu-dinal ligament:a review [J]. Neurosurg Focus. 2011;30(3):E1. Wada E, Suzuki S, Kanazawa A, et al. Subtotal corpectomy versus laminoplasty for multilevel cervical spondylotic myelopathy: a long-term follow-up study over 10 years. [J]. Spine. 2001;26(13):1448–0. Jain SK, Salunke PS, Vyas KH, et al. Multisegmental cervical ossification of the posterior longitudinal ligament: anterior vs posterior approach. [J] Neurol India. 2005;53(3):283–5. discussion 286. Ma L, Liu FY, Huo LS et al. Comparison of laminoplasty versus laminectomy and fusion in the treatment of multilevel cervical ossification of the posterior longitudinal ligament: a systematic review and meta-analysis [J]. Medicine (Baltimore), 2018, 97༈29༉:e11542. Baba H, Furusawa N, Chen Q et al. Cervical laminoplasty in patients with ossification of the posterior longitudinal ligaments.Paraplegia1995, 33(1):25–9. Lee SE, Chung CK, Jahng TA, et al. Long-term outcome of laminectomy for cervical ossification of the posterior longitudinal ligament. J Neurosurg Spine. 2013;18(5):465–71. Tomita K, Nomura S, Umeda S et al. Cervical laminoplasty to enlarge the spinal canal in multilevel ossification of the posterior longitudinal ligament with myelopathy. Arch Orthop TraumaSurg, 1988, 107(3):148–153 后路. Anderson PA, Matz PG, Groff MW, et al. Laminectomy and fusion for the treatment of cervical degenerative myelopathy [J]. J Neuro-surg Spine. 2009;11(2):150–6. Manzano G༲, Casella G, Wang MY, et al. A prospective, randomized trial comparing expansile cervical laminoplasty and cervical laminectomy and fusion for multilevel cervical myelopathy [J]. Neurosurgery. 2012;70(2):264–77. Lee DH, Joo YS, Hwang CJ, Lee CS, Cho JH. A novel technique to correct kyphosis in cervical myelopathy due to continuous-type ossification of the posterior longitudinal ligament. J Neurosurg Spine. 2017;26:325–30. Yamaura I. Anterior decompression for cervical myelopathy caused by ossification of the posterior longitudinal ligament–anterior floating method of OPLL. Nihon Seikeigeka Gakkai Zasshi. 1996;70(5):296–310. Japanese. PMID: 8727668. Fujiyoshi T, Yamazaki M, Kawabe J et al. A new concept for making decisions regarding the surgical approach for cervical ossification of the posterior longitudinal ligament:the K-line.Spine(Phila Pa 1976),2008,33(26):E990–3. Shinomiya K, Matsuoka T, Kurosa Y, et al. Anterior cervical decompression for cervical myelopathy caused by ossificationof the posterior longitudinal ligament (OPLL). Tokyo: Springer; 2006. pp. 209–18. Sakai KO et al. Five-year follow-up evaluation of surgical treatment for cervical myelopathy caused by ossification of the posterior longitudinal ligament: A prospective comparative study of anterior decompression and fusion with floating method versus laminoplasty[J].Spine, 2012. Chen Y, Liu X, Chen D, et al. Surgical strategy for ossification of the posterior longitudinal ligament in the cervical spine [J]. Ortho-pedics. 2012;35(8):e1231–1237. Yang H, Lu X, Wang X, Chen D, Yuan W, Yang L, et al. A new method to determine whether ossified posterior longitudinal ligament can be resected completely and safely: spinal canal Rule of Nine on axial computed tomography. Eur Spine J. 2015;24:1673–80. Choi BW, Song KJ, Chang H. Ossification of the posterior longitudinal ligament: a review of literature [J]. Asian Spine J. 2011;5(4):267–76. Fujiyoshi T, Yamazaki M, Kawabe J et al. A new concept for making decisions regarding the surgical approach for cervical ossification of the posterior longitudinal ligament:the l - line [J]. Spine (Phila Pa 1976), 2008, 33(26):990 །993. Cho JY, Chan CK, Lee SH, et al. Management of cerebrospinal fluid leakage after anterior decompression for ossification of posterior longitudinal ligament in the thoracic spine: the utilization of a volume-controlled pseudo meningocele. J Spinal DisordTech. 2012;25(4):E93. Cardoso MJ, Koski TR, Aruna G et al. Approach-related complications after decompression for cervical ossification of the posterior longitudinal ligament.Neurosurg Focus 2011, 30(3):285–93. Mazur M, Jost GF, Schmidt MH, et al. Management of cerebrospinal fluid leaks after anterior decompression for ossification of the posterior longitudinal ligament:a review of the literature [J]. Neurosurg Focus. 2011;300(3):E13. Lee SH, Kim KT, Lee JH, Kang KC, Jang SJ, Hwang SP, et al. 540° cervical realignment procedure for extensive cervical OPLL with kyphotic deformity. Spine (Phila Pa 1976). 2016;41:1876–83. Jing chuan SHI, Jian gang WANG, Yuan, et al. Anterior controllable anterior displacement and fusion for treatment of severe cervical ossification of posterior longitudinal ligament[J]. Acad J Second Military Med Univ. 2017;38(8):1053–9. Sun J, Shi J, Xu X et al. Anterior controllable antidisplacement and fusionsurgery for the treatment of multilevel severe ossification of the posterior longitudinal ligament with myelopathy: preliminary clinical results of a novel technique [J]. European Spine Journal, 2017,10.1007/s00586-017-5437-4. [Epubahead of print]. 22 Sun J, Yang H, Shi J et al. Morphometric analysis of uncinate process as a landmark for anterior controllable antedisplacement and fusion surgery: A study of radio logical anatomy[J]. World Neurosurgery, 2018, accepted. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted 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. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-7140591","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":504379966,"identity":"d6af067a-3f75-446a-9fb5-46ae5cb51d4a","order_by":0,"name":"Shuang Zhang","email":"","orcid":"","institution":"General Hospital of Southern Theatre Command","correspondingAuthor":false,"prefix":"","firstName":"Shuang","middleName":"","lastName":"Zhang","suffix":""},{"id":504379967,"identity":"2f63a987-8d14-450a-b516-afab6dffc859","order_by":1,"name":"Haozhi Yang","email":"","orcid":"","institution":"General Hospital of Southern Theatre Command","correspondingAuthor":false,"prefix":"","firstName":"Haozhi","middleName":"","lastName":"Yang","suffix":""},{"id":504379968,"identity":"32e2cad2-b7a9-4fff-a860-f1bb55b3fecb","order_by":2,"name":"Guoqiang Liu","email":"","orcid":"","institution":"General Hospital of Southern Theatre Command","correspondingAuthor":false,"prefix":"","firstName":"Guoqiang","middleName":"","lastName":"Liu","suffix":""},{"id":504379969,"identity":"3e2e91ab-1732-4b4c-a5eb-e73cbdec6825","order_by":3,"name":"Yuyue Chen","email":"","orcid":"","institution":"General Hospital of Southern Theatre Command","correspondingAuthor":false,"prefix":"","firstName":"Yuyue","middleName":"","lastName":"Chen","suffix":""},{"id":504379970,"identity":"68b10a0a-728a-4f0e-9006-e83c855abfbe","order_by":4,"name":"Rencai Ma","email":"","orcid":"","institution":"General Hospital of Southern Theatre Command","correspondingAuthor":false,"prefix":"","firstName":"Rencai","middleName":"","lastName":"Ma","suffix":""},{"id":504379971,"identity":"70aee02b-7e74-4027-9ddc-602f7e1f4604","order_by":5,"name":"Junlin Chen","email":"","orcid":"","institution":"General Hospital of Southern Theatre Command","correspondingAuthor":false,"prefix":"","firstName":"Junlin","middleName":"","lastName":"Chen","suffix":""},{"id":504379972,"identity":"aa81b5a7-6743-4866-8a83-015d04afc8ff","order_by":6,"name":"Xiangyang Ma","email":"","orcid":"","institution":"General Hospital of Southern Theatre Command","correspondingAuthor":false,"prefix":"","firstName":"Xiangyang","middleName":"","lastName":"Ma","suffix":""},{"id":504379973,"identity":"fc9f14fc-88eb-4a52-b457-c672f4b721a2","order_by":7,"name":"Jianhua Wang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA8UlEQVRIiWNgGAWjYBACxmYGBmYYR4KHgUGOjb39AGlajPl4ziQQtAlFS+I8CQcD/MrbmZ89LmyzS+yf3X7xxts999LbJBgSGH5UbMPjMDZz45ltyYkz7pwptpzzrDi3TbrxAGPPmdv4/GImzdvGnNtwIydNmudAQm6bzIEEZsY2fFrYvwG11OfOh2pJZ5NIMCCghQdky+HcDTfSj4G0JBCjpUya59zx+o03cpgt5xxIMGwDBvJBfH4x7D++TZqnrNpY7kb6wxtvDiTIy7e3H3zwowKPlgY4kwcRHQdwqgcCeQST/QE+haNgFIyCUTCCAQD2yVc+sgGTQQAAAABJRU5ErkJggg==","orcid":"","institution":"General Hospital of Southern Theatre Command","correspondingAuthor":true,"prefix":"","firstName":"Jianhua","middleName":"","lastName":"Wang","suffix":""}],"badges":[],"createdAt":"2025-07-16 13:38:27","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7140591/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7140591/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":90307861,"identity":"0f717aa5-2149-46ca-8842-cf8721ed2486","added_by":"auto","created_at":"2025-09-01 09:35:28","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":347203,"visible":true,"origin":"","legend":"\u003cp\u003eIllustration of the mechanism of the anterior hinge-like osteotomy through ossification and antedisplacement of the vertebral-ossification compound, combined with posterior single open-door laminoplasty technique. A: continuous-type of cervical OPLL (black area) with K-line negative. B: Hinge-like osteotomy through ossification at each disc level after finished posterior single open-door posterior laminoplasty. C: An antedisplacement of vertebre-ossification compound with a plate and autologous iliac bone results in K-line positive.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-7140591/v1/be552b340f14affa0aef5f4a.png"},{"id":90306483,"identity":"9db89953-2017-4e30-a5cc-e4e81ab7034f","added_by":"auto","created_at":"2025-09-01 09:27:29","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":1379676,"visible":true,"origin":"","legend":"\u003cp\u003eIntraoperative images of posterior cervical surgery and anterior cervical surgery. A: Resected the inferior articular processes of the cervical vertebrae (C2-C6) in a V-shaped osteotomy fashion and the lateral block joints were released to eliminate posterior resistance by the ultrasonic bone knife B:A pre-bent titanium plate of appropriate length was selected and the bones in front of the vertebrae were removed to increase the antedisplacement and shaping space.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-7140591/v1/0f066a8cfb682e67ae9a1ff6.png"},{"id":90306484,"identity":"a90032fc-b77a-4530-9553-650eb7812019","added_by":"auto","created_at":"2025-09-01 09:27:29","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":603974,"visible":true,"origin":"","legend":"\u003cp\u003eCase1. Preoperative and Postoperative images of a 57-year-old man who exhibited numbness and fatigue in limbs for 38 months. A: Preoperative lateral radiograph shows disappearance of cervical lordosis. B: Postoperative lateral radiograph shows improvement in cervical lordosis. C: Preoperative sagittal CT display of continuous-type cervical OPLL with cervical canal stenosis. D: Postoperativesagittal CT display of cervical Hinge-like osteotomy through ossification（arrow）and significant enlargement of cervical canal. E: Preoperative MR shows significant compression of the spinal cord F: Preoperative MR showssufficient spinal cord decompression.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-7140591/v1/f72ddf10cfbbe15175ddcfc4.png"},{"id":90306493,"identity":"d9f61478-ac71-4fc3-a555-6e9a2e5d0e01","added_by":"auto","created_at":"2025-09-01 09:27:29","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":1229189,"visible":true,"origin":"","legend":"\u003cp\u003eCase 2. Preoperative and Postoperative images of a 62-year-old man who exhibited Hand numbness for 36 months. A: Preoperative lateral radiograph shows disappearance of cervical lordosis and the patient was K-line negative and the dashed line indicates the OPLL mass. B: Preoperative sagittal CT displayed cervical OPLL in C4-C6. C: Cervical OPLL with spinal stenosis were shown on an axial CT scan. D: Preoperative MR showed significant compression of the spinal cord E: Postoperative lateral radiograph shows improvement in cervical lordosis and transition from K-line negative to K-line positive. F: Postoperative sagittal CT displayed cervical OPLL with K-line positive undergone Hinge-like osteotomy through ossification (arrows). G: Significant enlargement of the vertebral canal shown on an axial CT scan. H: Postoperative MR shows sufficient spinal cord decompression (arrows).\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-7140591/v1/80701de884d33675c681de6b.png"},{"id":90306500,"identity":"d710906a-cb62-417e-b47a-9699b4ce9bb6","added_by":"auto","created_at":"2025-09-01 09:27:29","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":1597573,"visible":true,"origin":"","legend":"\u003cp\u003eCase 3. Preoperative and Postoperative images of a 50-year-old woman who exhibited Numbness and fatigue in limbs for 12 months, bowel and bladder disturbances for 3 days. A: Preoperative cervical lateral radiograph shows the patient’s cervical lordosis was disappeared and the K-line was negative. Dashed line indicates the OPLL mass. B: Preoperative sagittal CT displayed cervical OPLL in C2-C4 with cervical canal stenosis. C: Preoperative MR showed significant compression of the spinal cord. D: Postoperative cervical lateral radiograph shows improvement in cervical lordosis and the K-line was positive. E: Postoperative sagittal CT displayed the patient undergone Hinge-like osteotomy through ossification and the cervical canal was enlarged significantly. F: PostoperativeMR showed sufficient spinal cord decompression.\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-7140591/v1/1dd29ab6dbbb6796e642040e.png"},{"id":90306487,"identity":"9c33cadc-ca77-455d-ad85-5abc85fd7e9a","added_by":"auto","created_at":"2025-09-01 09:27:29","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":1208726,"visible":true,"origin":"","legend":"\u003cp\u003eCase 4. Preoperative and Postoperative images of a 62-year-old man who exhibited numbness and fatigue in limbs for 3 months A: Preoperative lateral X-ray showed disappearance of cervical lordosis and OPLL mass in C4-C6. B: Preoperative sagittal CT displayed continuous-type cervical OPLL in C4-C6. C: Huge cervical OPLL mass with spinal stenosis were shown on an axial CT scan. D: Preoperative MR showed significant compression of the spinal cord. E: Postoperative lateral radiograph shows improvement in cervical. F: Postoperative sagittal CT displayed cervical OPLL undergone Hinge-like osteotomy through ossification (arrows). G: Significant enlargement of the vertebral canal shown on an axial CT scan. H: Postoperative MR shows sufficient spinal cord decompression (arrow).\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-7140591/v1/0f2303da6dad253dad631b49.png"},{"id":95818863,"identity":"891f760d-778b-49ef-9d3a-2b80da3e1587","added_by":"auto","created_at":"2025-11-13 10:34:34","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":9489384,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7140591/v1/f57a1fd7-c7de-4982-9cf9-9ea2092c9ce6.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"A novel surgical technique for the treatment of continuous-type ossification of the posterior longitudinal ligament with K-line negative","fulltext":[{"header":"Introduction","content":"\u003cp\u003eCervical ossification of posterior longitudinal ligament (OPLL) refers to a multifactorial disease characterized by ectopic bone hypertrophy, ossification and hyperplasia of the posterior longitudinal ligament, resulting in spinal stenosis, compression of the cervical spinal cord, and associated spinal nerve damage \u003csup\u003e[\u003cspan additionalcitationids=\"CR2 CR3\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e–\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/sup\u003e. Its ossifications continue to grow, ultimately leading limb sensation, movement disorders, as well as dysfunction of the visceral autonomic nervous system \u003csup\u003e[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eThe ossified posterior longitudinal ligament of the cervical spine is located anterior to the spinal canal. Conservative methods, such as medication and physical therapy, may provide temporary relief of symptoms but do not address the underlying issue of spinal cord compression caused by cervical OPLL. The surgical treatment of cervical OPLL involves decompression of the spinal cord and stabilization of the spine. Various surgical techniques can be used depending on the characteristics of the OPLL, such as the location, extent, and stiffness of the ossification. Due to the complexity of the condition of cervical OPLL, long-term chronic compression can lead to adhesions between ossification and the dura, often complicating direct anterior decompression. Currently, the predominant surgical approach for cervical spinal canal stenosis involves posterior enlargement and decompression, primarily utilizing laminoplasty \u003csup\u003e[\u003cspan additionalcitationids=\"CR7 CR8 CR9 CR10\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e–\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]\u003c/sup\u003e. The surgical principle is to expand the cervical spinal canal and bring the spinal cord to drift backwards avoiding compression from the front of the spinal cord and achieving effective decompression. Compared to the direct anterior decompression \u003csup\u003e[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]\u003c/sup\u003e, the posterior laminoplasty was considered a relatively simpler and safer approach for treating most cases of cervical OPLL, achieving favorable therapeutic outcomes.\u003c/p\u003e\u003cp\u003eHowever, it is mainly suitable for cervical OPLL patients with positive K-line or normal cervical lordosis. For cervical OPLL patients with poor cervical lordosis or negative K-line, ever after posterior laminectomy decompression is performed, the spinal cord is still difficult to effectively drift backward to avoid anterior compression and achieve the ideal therapeutic effect. It is well known that cervical OPLL patients with continuous type ossification of the posterior longitudinal ligament and straight stiff cervical spine are difficult to treat.\u003c/p\u003e\u003cp\u003eTo treat cervical OPLL patient with negative K-line, we have chosen the anterior approach to perform direct decompression with such as ACAF technique \u003csup\u003e[\u003cspan additionalcitationids=\"CR23\" citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e–\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]\u003c/sup\u003e. Besides, we can directly fully or partially remove ossifications with so called floating technique \u003csup\u003e[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]\u003c/sup\u003e. Actually, the latter technique is safer and more feasible for treating OPLL with adhesion between ossification and dura.\u003c/p\u003e\u003cp\u003eThe principle of ACAF surgery is to separate the cervical vertebral ossification complex as a whole form the surrounding tissues and move it forward as a whole, in order to relieve anterior compression of the cervical spinal cord and expand the volume of the vertebral canal. This technique involves controllable anterior displacement of the cervical vertebral ossification complex (VOC) as a whole, thereby increasing the vertebral canal volume and relieving anterior compression of the cervical spinal cord, without requiring direct removal of ossification\u003c/p\u003e\u003cp\u003eDuring the surgical procedures, creating narrow bone grooves on both sides of the ossification boundary to separate the vertebral ossification complex from the surrounding structure was a critical step. It is crucial to accurately determine the exact boundaries of ossification and perform proper anatomical dissection. However, there are risks of venous plexus bleeding, dural tear and cerebrospinal fluid (CSF) leakage. Additionally, when the spinal canal on both sides is extremely narrow, there is still a potential risk of nerve root and spinal cord damage. A more convenient and safer technique was designed to address the issue of spinal cord compression in patients with poor cervical lordosis and continuous-type cervical OPLL. We propose an innovative approach that involves utilizing anterior hinge-like osteotomy through ossification and ante-displacement of the vertebral-ossification compound, combined with posterior single open-door laminoplasty(illustrated in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e4\u003c/span\u003e), to treat continuous-type cervical OPLL with K-line negative.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cb\u003ePatient Population\u003c/b\u003e\u003c/p\u003e\u003cp\u003eIn this study, four patients with continuous-type cervical OPLL, as confirmed by CT and radiography, were found to have cervical kyphosis without lordosis and were recognized as K-line negative. All patients presented with symptoms associated with cervical myelopathy caused by spinal cord compression. Preoperative MRI of the cervical spine revealed cervical spinal stenosis with anterior compression of the spinal cord by the ossification (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e1\u003c/span\u003ef). Cervical lateral radiograph showed that the midpoint of the C2 spinal canal was connected to the midpoint of the C7 spinal canal (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e2\u003c/span\u003e), indicating that the highest point of ossification of the posterior longitudinal ligament exceeded the K-line \u003csup\u003e[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]\u003c/sup\u003e. Before surgery, pain levels were assessed using the Visual Analog Scale (VAS), while the degree of disability was evaluated using the Neck Disability Index (NDI) and Japan Orthopedic Association (JOA) scores. Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e provides an overview of the patients' general condition, main symptoms, related scores, and imaging findings.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cdiv class=\"gridtable\"\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=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eBasic information of the 4 patients with continuous-type cervical OPLL\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"8\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCase\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eAge\u003c/p\u003e\u003cp\u003e(yrs), Sex\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eMajor Symptoms\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eduration of symptoms (mos)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"3\" nameend=\"c7\" namest=\"c5\"\u003e\u003cp\u003eC2–7 Lordosis\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c8\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eOPLL segment\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNo.\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNeutral\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003eFlexion\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e\u003cp\u003eExtension\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e57, M\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNumbness and fatigue in upper limbs\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e38\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e−16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003eC2-5\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e56, M\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eHand numbness\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e36\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e−16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e21\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003eC3–6\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e50, F\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNumbness and fatigue in limbs, bowel and bladder disturbances\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e−2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e−19\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e13\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003eC4–6\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e62, M\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNumbness and fatigue in upper limbs\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e−1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e−26\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e18\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003eC2–4\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eThese patients underwent a novel surgical procedure involving anterior hinge-like osteotomy through the ossification and ante-displacement of the vertebra-ossification compound, combined with posterior single open-door laminoplasty.\u003c/p\u003e\u003cp\u003e\u003cb\u003eSurgical Technique\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThe surgery was conducted under general anesthesia following completion of necessary preoperative preparations. It involved posterior single open-door laminoplasty, posterior lateral mass joint osteotomy and release, combined with anterior hinge-like osteotomy through ossification and ante-displacement of the vertebral-ossification compound with plate and screw pull force to reconstruct the cervical lordosis. The patient was positioned prone on the operating table with the head placed securely in the head frame, while maintaining cervical spine traction. The operating table was set in a head-high and foot-low position. Posterior single open-door laminoplasty was carried out using a high-speed burr, targeting the C3-C6, C2-C7, or C3-C7 levels. Subsequently, the ultrasonic osteotome was employed to resect the inferior articular processes of the cervical vertebrae (C2-C6) with a V-shaped osteotomy fashion. Lateral block joints were released to eliminate posterior resistance, allowing for hinge-like movement of the cervical spine (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eAfter the completion of the posterior surgery, the patients underwent anterior hinge-like osteotomy through ossification and ante-displacement of the cervical vertebrae. The anterior structure of the C3 to C7 vertebral body was fully exposed and a high-speed burr was used to expand each intervertebral space appropriately, providing more space for deep operations. The intervertebral disc tissue was removed until the deep hard ossified ligament was reached. Then, an ultrasonic bone blade was used to horizontally cut off the ossified ligaments to create hinges. The operation was immediately stopped when there was a slight sense of breakthrough, indicating that the ossified ligaments had been cut through. The size of the intervertebral spaces was measured and small bone blocks, slightly thicker in the front and thinner in the back, were prepared from the patient's autologous iliac bone and implanted into the intervertebral space. the bones in front of the vertebrae were removed to increase the antedisplacement and shaping space (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e4\u003c/span\u003e). A pre-bent titanium plate of appropriate length was selected first, then fix the plate to the vertebrae at both ends with screws, then gradually screw of the middle vertebral segment to pull the vertebrae ossification complex forward, and forming the cervical lordosis. After placing the drainage, the incision was sutured to complete the surgery.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eAll 4 patients successfully underwent surgery and were monitored in the intensive care unit for one day to assess airway function and vital signs. The average operation time was 325.5\u0026thinsp;\u0026plusmn;\u0026thinsp;16.5 minutes, with an average blood loss of 452.5\u0026thinsp;\u0026plusmn;\u0026thinsp;23.5 milliliters. CSF leaking occurred in 1 patient during the osteotomy with ultrasonic osteotome at the ossification ligament. We immediately placed lumbar cistern drainage in the patient, regularly draining around 300ml of cerebrospinal fluid every day, and after 5 days, the tube was removed. The patient's cervical wound healed smoothly without any sequelae. All the 4 patients\u0026rsquo; clinical symptoms and scores showed significant improvement. The NDI score, VAS score, and JOA score all improved in all patients (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Postoperative CT scans displayed a considerable enlargement of the cervical spinal canal, and the ossification of the posterior longitudinal ligament of the cervical spine had shifted forward, resulting in the formation of cervical lordosis. Postoperative lateral radiographs and CT scans confirmed that all patients transitioned from K-line negative to K-line positive (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ed, \u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ee and Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003ee, \u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003ef, \u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eg). Postoperative MRI scans demonstrated a notable increase in the size of the cervical spinal canal, improved cervical sagittal alignment, and the relieve of spinal cord compression (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ef and Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eh).\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 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003ePreoperative and postoperative NDI scores, JOA scores and VAS scores.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"7\"\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\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003csub\u003eCase\u003c/sub\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eNDI scores\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e\u003cp\u003eJOA scores\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e\u003cp\u003eVAS scores\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNo.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ePreoperative\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePostoperative\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003ePreoperative\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003ePostoperative\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003ePreoperative\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003ePostoperative\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e6\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e3\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e13\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eCervical OPLL patients often require surgical intervention due to the growth of ossifications that compress the spinal cord and/or nerve roots, leading to sensory and motor dysfunction in the limbs. There are two main types of surgical approaches for treating cervical OPLL: posterior surgery and anterior surgery \u003csup\u003e[\u003cspan additionalcitationids=\"CR15 CR16 CR17\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]\u003c/sup\u003e. Posterior surgeries primarily include posterior cervical laminoplasty, posterior cervical laminectomy combined with internal fixation. Anterior surgeries involve direct resection of cervical anterior ossification for decompression, or anterior controllable antedisplacement and fusion (ACAF). Although the selection of an anterior or posterior approach remains controversial, multilevel cord compression caused by ossification of the posterior longitudinal ligament (OPLL) and preoperative lordotic sagittal alignment are conditions that favor a posterior approach. However, performing posterior laminoplasty or laminectomy in patients with cervical kyphosis may result in poor clinical and radiological outcomes.\u003c/p\u003e\u003cp\u003eIn 2008, Japanese scholars \u003csup\u003e[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]\u003c/sup\u003e recognized the significant impact of the physiological lordosis of the cervical spine on the effectiveness of posterior cervical laminoplasty surgery and proposed the K-line method for assessment. The K-line refers to a line connecting the midpoint of the C2 spinal canal with the midpoint of the C7 spinal canal on the cervical lateral radiograph. K-line negative indicates that the highest point of the ossification material exceeds the K-line, suggesting a reduced physiological curvature or extensive ossification. Conversely, K-line positive suggests that the highest point of ossification is located in front of the K-line, which could imply better surgical outcomes with posterior laminoplasty. It is generally believed that OPLL patients with K-line positive achieve better therapeutic outcomes with posterior laminoplasty. This is because patients with cervical lordosis have sufficient space for the spinal cord to drift backwards, preventing compression of the ossification after vertebral canal expansion.\u003c/p\u003e\u003cp\u003eFor OPLL patients with K-line negative, characterized by reduced cervical lordosis and a rigid cervical spine, posterior cervical laminoplasty often yield less favorable outcomes. This is due to the limit ability of the spinal cord to drift posteriorly even after vertebral canal enlargement. So, it is generally recommended to perform direct anterior cervical ossification resection or ACAF technique for treatment of such patients. Direct anterior decompression surgery, involving resection of ossification compound, was a technically demanding and high-risk procedure for most spine surgeons. It is associated with a high complication rate, including dural tear, spinal cord injury, and uncontrollable venous plexus bleeding, largely due to the long-term compression and adhesion of ossification with the dural sac \u003csup\u003e[\u003cspan additionalcitationids=\"CR21\" citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]\u003c/sup\u003e. To address the challenges associated with direct resection of OPLL for decompression, an alternative technique known as Anterior Cervical Foraminotomy (ACAF) has been introduced in recent years. Unlike traditional methods, ACAF does not necessitate the complete dissection or direct removal of ossified structures within the vertebral canal. This approach effectively minimizes the risk of dural tear and uncontrollable venous plexus bleeding \u003csup\u003e[\u003cspan additionalcitationids=\"CR25\" citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]\u003c/sup\u003e. However, despite its advantages, the ACAF technique remains technically demanding and presents significant challenges for many spine surgeons. Consequently, it requires a longer learning curve for mastery.\u003c/p\u003e\u003cp\u003eApart from the anterior decompression for treatment OPLL with negative K line by ACAF or ACCF, another strategy for treatment of this complex disorders was reconstruction of the lordosis combined with posterior laminoplasty. Some scholars recommended the use of posterior cervical laminectomy and reconstruction of cervical lordosis through a posterior cervical pedicle screw-rod system to improve the efficacy of laminoplasty surgery \u003csup\u003e[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]\u003c/sup\u003e. This technique proved to be effective for non-continuous-types cervical OPLL patients with good cervical mobility. But for patients with continuous-types cervical OPLL with long segments and a stiff cervical spine, the posterior screw-rod system is insufficient to reshape the cervical lordosis, often resulting in poor result.\u003c/p\u003e\u003cp\u003eTo enhance the flexibility of the cervical spine in patients with continuous ossification of OPLL, we have developed a novel method that involves reconstructing cervical lordosis by cutting off the ossified band through the intervertebral space and reshaping the anterior arch using a cervical plate. This procedure, termed the \u0026ldquo;anterior hinge-like osteotomy through ossification and cervical lordosis reconstruction techs (HOLR).\u0026rdquo; Our HOLR technique combined with the posterior single open-door laminoplasty has developed to treat the continuous OPLL with negative K line. In this study, all patients initially underwent posterior laminoplasty to enlarge the cervical vertebral canal. Subsequently, cervical lordosis was reconstructed using the HOLR technique in a single stage (3 cases) or a two-stage procedure (1 case). At the follow-up, all patients demonstrated significant improvement in nerve function compared to pre-surgery. Radiographic and CT findings revealed that cervical lordosis improved from K-negative to K-positive. MRI showed a marked enlargement of the vertebral canal and a reduction in anterior compression compared to pre-surgery measurements.\u003c/p\u003e\u003cp\u003eThe principle of this novel technique is to transform a rigid structure into a flexible one by transverse cutting using an ultrasonic osteotome in the cervical gaps. Compared with the greenstick fracture technique, this technology demonstrated more effective reconstruction of cervical lordosis. During the posterior single open-door laminoplasty, V-grade osteotomy and release of lateral block joints were performed, as previously reported \u003csup\u003e[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]\u003c/sup\u003e. Our technique only requires posterior-anterior approach, which was more simplified than the posterior-anterior-posterior procedures. Theoretically, the novel technology is safer than ACAF techs, because it does not require complete dissociation of the ossification or direct removal of ossification in the vertebral canal, thus avoiding dural tear and uncontrollable venous plexus bleeding. Additionally, the antedisplacement of cervical does not cause new compression of the cervical spinal cord due to the significant enlargement of the vertebral canal diameter through posterior single open-door laminoplasty. All procedures and manipulations are controllable and safety and is readily mastered by general spinal surgeons. However, due to the limited number of cases currently being performed, the surgical shortcomings and limitations of this technology require further clinical observation.\u003c/p\u003e\u003cp\u003eIn summary, the continuous-type cervical OPLL with stiff cervical alignment and K-line negative often poses a significant challenge in clinical treatment. Simply performing posterior cervical laminoplasty often falls short of optimal results. By combining posterior cervical laminoplasty with HOLR could provide a novel way to antedisplace the cervical ossification complex safely and reconstruct the lordosis of the cervical spine. This approach effectively alleviates the anterior compression of the spinal cord and achieves a desirable decompression effect. Nevertheless, further research involving a larger number of cases is necessary to establish its generalizability and ensure its safety.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participant\u003c/strong\u003e\u003cp\u003eThis study was conducted in accordance with the principles of the Declaration of Helsinki. All participants (or their legal guardians) provided written informed consent for participation. The study protocol approved by the Local Ethics Committee of General Hospital of Southern Theatre Command. Personal identifiers were removed from the anonymized datasets to protect participant privacy.\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eClinical trial number\u003c/b\u003e\u003c/p\u003e\u003cp\u003eNot applicable.\u003c/p\u003e\u003cp\u003e\u003ch2\u003eConsent for publication\u003c/h2\u003e\u003cp\u003e All participants (or their legal guardians) provided written informed consent for the publication of identifiable data, including medical images and video.\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003ch2\u003eCompeting interests\u003c/h2\u003e\u003cp\u003eThe authors declare no completing interests.\u003c/p\u003e\u003c/p\u003e\u003ch2\u003eFunding\u003c/h2\u003e\u003cp\u003eNot applicable.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eShuang Zhang: Writing\u0026ndash;original draft, Data curation, Conceptualization. Haozhi Yang: Writing\u0026ndash;review \u0026amp; editing, Supervision, Methodology. Guoqiang Liu: Writing\u0026ndash;original draft, Software, Methodology, Data curation, Conceptualization. Yuyue Chen: Writing\u0026ndash;review \u0026amp; editing, Supervision. Rencai Ma: Writing \u0026ndash; review \u0026amp; editing, Supervision. Junlin Chen: Writing\u0026ndash;review \u0026amp; editing, Validation, Supervision. Xiangyang Ma: Writing\u0026ndash;review \u0026amp; editing, Formal analysis, Conceptualization. Jianhua Wang: Writing\u0026ndash;review \u0026amp; editing, Writing\u0026ndash;original draft, Supervision, Methodology, Investigation, Formal analysis, Data curation.\u003c/p\u003e\u003ch2\u003eAcknowledgements\u003c/h2\u003e\u003cp\u003eNot applicable.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eThe datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eNam DC, Lee HJ, Lee CJ, et al. Molecular Pathophysiology of Ossification of the Posterior Longitudinal Ligament (OPLL). Biomol Ther (Seoul). 2019;27(4):342\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSaetia K, Cho D, Lee S, et al. Ossification of the posterior longitu-dinal ligament:a review [J]. Neurosurg Focus. 2011;30(3):E1.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWada E, Suzuki S, Kanazawa A, et al. Subtotal corpectomy versus laminoplasty for multilevel cervical spondylotic myelopathy: a long-term follow-up study over 10 years. [J]. Spine. 2001;26(13):1448\u0026ndash;0.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJain SK, Salunke PS, Vyas KH, et al. Multisegmental cervical ossification of the posterior longitudinal ligament: anterior vs posterior approach. [J] Neurol India. 2005;53(3):283\u0026ndash;5. discussion 286.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMa L, Liu FY, Huo LS et al. Comparison of laminoplasty versus laminectomy and fusion in the treatment of multilevel cervical ossification of the posterior longitudinal ligament: a systematic review and meta-analysis [J]. Medicine (Baltimore), 2018, 97༈29༉:e11542.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBaba H, Furusawa N, Chen Q et al. Cervical laminoplasty in patients with ossification of the posterior longitudinal ligaments.Paraplegia1995, 33(1):25\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLee SE, Chung CK, Jahng TA, et al. Long-term outcome of laminectomy for cervical ossification of the posterior longitudinal ligament. J Neurosurg Spine. 2013;18(5):465\u0026ndash;71.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTomita K, Nomura S, Umeda S et al. Cervical laminoplasty to enlarge the spinal canal in multilevel ossification of the posterior longitudinal ligament with myelopathy. Arch Orthop TraumaSurg, 1988, 107(3):148\u0026ndash;153 后\u0026amp;#36335.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAnderson PA, Matz PG, Groff MW, et al. Laminectomy and fusion for the treatment of cervical degenerative myelopathy [J]. J Neuro-surg Spine. 2009;11(2):150\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eManzano G༲, Casella G, Wang MY, et al. A prospective, randomized trial comparing expansile cervical laminoplasty and cervical laminectomy and fusion for multilevel cervical myelopathy [J]. Neurosurgery. 2012;70(2):264\u0026ndash;77.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLee DH, Joo YS, Hwang CJ, Lee CS, Cho JH. A novel technique to correct kyphosis in cervical myelopathy due to continuous-type ossification of the posterior longitudinal ligament. J Neurosurg Spine. 2017;26:325\u0026ndash;30.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYamaura I. Anterior decompression for cervical myelopathy caused by ossification of the posterior longitudinal ligament\u0026ndash;anterior floating method of OPLL. Nihon Seikeigeka Gakkai Zasshi. 1996;70(5):296\u0026ndash;310. Japanese. PMID: 8727668.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eFujiyoshi T, Yamazaki M, Kawabe J et al. A new concept for making decisions regarding the surgical approach for cervical ossification of the posterior longitudinal ligament:the K-line.Spine(Phila Pa 1976),2008,33(26):E990\u0026ndash;3.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eShinomiya K, Matsuoka T, Kurosa Y, et al. Anterior cervical decompression for cervical myelopathy caused by ossificationof the posterior longitudinal ligament (OPLL). Tokyo: Springer; 2006. pp. 209\u0026ndash;18.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSakai KO et al. Five-year follow-up evaluation of surgical treatment for cervical myelopathy caused by ossification of the posterior longitudinal ligament: A prospective comparative study of anterior decompression and fusion with floating method versus laminoplasty[J].Spine, 2012.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChen Y, Liu X, Chen D, et al. Surgical strategy for ossification of the posterior longitudinal ligament in the cervical spine [J]. Ortho-pedics. 2012;35(8):e1231\u0026ndash;1237.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYang H, Lu X, Wang X, Chen D, Yuan W, Yang L, et al. A new method to determine whether ossified posterior longitudinal ligament can be resected completely and safely: spinal canal Rule of Nine on axial computed tomography. Eur Spine J. 2015;24:1673\u0026ndash;80.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChoi BW, Song KJ, Chang H. Ossification of the posterior longitudinal ligament: a review of literature [J]. Asian Spine J. 2011;5(4):267\u0026ndash;76.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eFujiyoshi T, Yamazaki M, Kawabe J et al. A new concept for making decisions regarding the surgical approach for cervical ossification of the posterior longitudinal ligament:the l - line [J]. Spine (Phila Pa 1976), 2008, 33(26):990 །993.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCho JY, Chan CK, Lee SH, et al. Management of cerebrospinal fluid leakage after anterior decompression for ossification of posterior longitudinal ligament in the thoracic spine: the utilization of a volume-controlled pseudo meningocele. J Spinal DisordTech. 2012;25(4):E93.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCardoso MJ, Koski TR, Aruna G et al. Approach-related complications after decompression for cervical ossification of the posterior longitudinal ligament.Neurosurg Focus 2011, 30(3):285\u0026ndash;93.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMazur M, Jost GF, Schmidt MH, et al. Management of cerebrospinal fluid leaks after anterior decompression for ossification of the posterior longitudinal ligament:a review of the literature [J]. Neurosurg Focus. 2011;300(3):E13.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLee SH, Kim KT, Lee JH, Kang KC, Jang SJ, Hwang SP, et al. 540\u0026deg; cervical realignment procedure for extensive cervical OPLL with kyphotic deformity. Spine (Phila Pa 1976). 2016;41:1876\u0026ndash;83.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJing chuan SHI, Jian gang WANG, Yuan, et al. Anterior controllable anterior displacement and fusion for treatment of severe cervical ossification of posterior longitudinal ligament[J]. Acad J Second Military Med Univ. 2017;38(8):1053\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSun J, Shi J, Xu X et al. Anterior controllable antidisplacement and fusionsurgery for the treatment of multilevel severe ossification of the posterior longitudinal ligament with myelopathy: preliminary clinical results of a novel technique [J]. European Spine Journal, 2017,10.1007/s00586-017-5437-4. [Epubahead of print].\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003e22 Sun J, Yang H, Shi J et al. Morphometric analysis of uncinate process as a landmark for anterior controllable antedisplacement and fusion surgery: A study of radio logical anatomy[J]. World Neurosurgery, 2018, accepted.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"OPLL (ossification of the posterior longitudinal ligament), anterior hinge-like osteotomy and cervical lordosis reconstruction (HOLR), single open-door laminoplasty, K-line","lastPublishedDoi":"10.21203/rs.3.rs-7140591/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7140591/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eObjective\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTo investigate a novel surgical technique for the treatment of patients with continuous-type cervical ossification of the posterior longitudinal ligament (OPLL) with K-line negative using anterior hinge-like osteotomy through ossification and antedisplacement of the vertebral-ossification compound, combined with posterior single open-door laminoplasty.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFour patients with continuous-type cervical ossification of the posterior longitudinal ligament (OPLL), showing straight and stiff cervical alignment without lordosis, and identified as K-line negative, underwent a novel surgical procedure. Initially, posterior single open-door laminoplasty was performed in combination with lower facet V-shaped osteotomy and lateral mass joint release. Subsequently, an osteotomy was conducted through the ossification ligament using a hinge-like technique, along with anterior displacing and pulling using pre-bent plates and screws, to restore cervical lordosis. The duration of surgery, amount of blood loss, and the following parameters were assessed using radiography, CT scans, and MRI: cervical lordosis, spinal canal enlargement, and medullary decompression. Pain levels were measured using the Visual Analog Scale (VAS), while disability was evaluated using the Neck Disability Index (NDI) and Japan Orthopedic Association (JOA) scores, both before and after surgery.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe surgery was successful, with an average operation time of 240 ±38 minutes and a bleeding volume of 400 ± 50ml. Postoperative images revealed a significant enlargement of the cervical spinal canal, improved cervical lordosis compared to preoperative measurements, and resolved compression of the spinal cord. The postoperative patients experienced a significant improvement in their clinical symptoms, as evidenced by improved VAS, NDI, and JOA scores. This indicates that the novel surgery effectively provided sufficient decompression.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe novel technique of anterior hinge-like osteotomy through ossification and antedisplacement of the vertebral-ossification compound, combined with posterior single open-door laminoplasty, has demonstrated the ability to restore cervical lordosis and enhance the outcomes of single posterior laminoplasty in the treatment of cervical OPLL with negative K-line. This innovative approach offers a new and promising solution for treating complex cases of cervical OPLL.\u003c/p\u003e","manuscriptTitle":"A novel surgical technique for the treatment of continuous-type ossification of the posterior longitudinal ligament with K-line negative","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-01 09:27:24","doi":"10.21203/rs.3.rs-7140591/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"89d1c80a-ffc2-4879-bd18-d267b13f22a0","owner":[],"postedDate":"September 1st, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-11-12T07:09:04+00:00","versionOfRecord":[],"versionCreatedAt":"2025-09-01 09:27:24","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7140591","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7140591","identity":"rs-7140591","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}