Advances in surgical strategies for ossification of posterior longitudinal ligament involving the C 2 segment / 中国修复重建外科杂志

OBJECTIVE@#To evaluate the application of surgical strategies for the treatment of cervical ossification of the posterior longitudinal ligament (OPLL) involving the C 2 segment.@*METHODS@#The literature about the surgery for cervical OPLL involving C 2 segment was reviewed, and the indications, advantages, and disadvantages of surgery were summarized.@*RESULTS@#For cervical OPLL involving the C 2 segments, laminectomy is suitable for patients with OPLL involving multiple segments, often combined with screw fixation, and has the advantages of adequate decompression and restoration of cervical curvature, with the disadvantages of loss of cervical fixed segmental mobility. Canal-expansive laminoplasty is suitable for patients with positive K-line and has the advantages of simple operation and preservation of cervical segmental mobility, and the disadvantages include progression of ossification, axial symptoms, and fracture of the portal axis. Dome-like laminoplasty is suitable for patients without kyphosis/cervical instability and with negative R-line, and can reduce the occurrence of axial symptoms, with the disadvantage of limited decompression. The Shelter technique is suitable for patients with single/double segments and canal encroachment >50% and allows for direct decompression, but is technically demanding and involves risk of dural tear and nerve injury. Double-dome laminoplasty is suitable for patients without kyphosis/cervical instability. Its advantages are the reduction of damage to the cervical semispinal muscles and attachment points and maintenance of cervical curvature, but there is progress in postoperative ossification.@*CONCLUSION@#OPLL involving the C 2 segment is a complex subtype of cervical OPLL, which is mainly treated through posterior surgery. However, the degree of spinal cord floatation is limited, and with the progress of ossification, the long-term effectiveness is poor. More research is needed to address the etiology of OPLL and to establish a systematic treatment strategy for cervical OPLL involving the C 2 segment.

Trauma medular cervical en pacientes con osificación del ligamento longitudinal posterior sin evidencia de fractura. Serie de casos y revisión bibliográfica / Traumatic acute spinal cord injury associated with ossification of the cervical posterior longitudinal ligament without tomographic evidence of bone trauma. Case series and literature review

Objetivos: Presentar una serie de casos de lesión medular aguda traumática asociada a osificación del ligamento longitudinal posterior cervical sin evidencia tomográfica de trauma óseo y realizar una revisión narrativa de la bibliografía sobre su tratamiento y pronóstico posoperatorio. Materiales y métodos: Descripción de una serie de pacientes con lesión medular aguda traumática y osificación del ligamento longitudinal posterior cervical, tratados por nuestro equipo, entre enero de 2012 y diciembre de 2019. Se excluyó a pacientes con fracturas o luxaciones vertebrales asociadas, aquellos derivados a otro centro antes del tratamiento y con registros incompletos. Además, se llevó a cabo una revisión narrativa de la bibliografía sobre el tratamiento y el pronóstico posoperatorio de esta asociación en la última década. Con nuestra estrategia de búsqueda, se obtuvieron 10 artículos, a partir de los cuales se desarrolló la revisión narrativa.Resultados: Se conformó una muestra de 5 casos, todos hombres, con una edad promedio de 62.2 años (DE ± 9,36), 4 pacientes fueron operados por vía posterior y uno recibió tratamiento conservador. Conclusiones: La lesión medular aguda traumática asociada a osificación del ligamento longitudinal posterior cervical es infrecuente en países no asiáticos, precedida, en nuestra región, por un reporte de caso aislado. La revisión de la bibliografía actual sugiere al tratamiento quirúrgico oportuno por sobre el tratamiento conservador, pero persisten las controversias al respecto. Nivel de Evidencia: IV

Objectives: To present a case series of traumatic acute spinal cord injury associated with ossification of the cervical posterior longitudinal ligament (OPLL) without tomographic evidence of bone trauma and to perform a narrative review of the literature on its treatment and postoperative prognosis. Materials and methods: We described a case series of patients with traumatic spinal cord injury and association of cervical OLLP, treated by our team during the period January 2012 - December 2019. We excluded patients with an association of vertebral fractures and/or dislocations, and those referred to another center before treatment and with incomplete records. Additionally, a narrative review of the literature on postoperative treatment and prognosis of this association was carried out. Ten articles were obtained with our search strategy for the narrative review. Results: A sample of 5 cases was formed, all males, with an average age of 62.2 ( ± 9.36), 4 cases were surgically treated by a posterior approach and 1 case was conservatively treated. Conclusion: We presented a case series of a rare association in our region, preceded only by an isolated case report. The review of the current literature suggests timely surgical treatment over conservative treatment, but controversies persist in this regard. Level of Evidence: IV

Síndrome de forestier: caso clínico y revisión de la literatura / Forestier syndrome: clinical case and literature review

Antecedentes: El síndrome de Forestier también conocido como Hiperostosis Esquelética Idiopática Difusa (DISH, por sus siglas en inglés), es una enfermedad de etiología desco-nocida que se caracteriza por osificación del ligamento espinal anterior, siendo las porciones cervicales y torácicas las que se afectan más frecuentemente. Esta enfermedad es más frecuente en hombres y se asocia con diabetes, hipertensión arterial, disli-pidemia y trastornos endocrinos. Descripción del caso clínico:Paciente femenina de 63 años con antecedente de dolor cervical desde hace 32 años, que 6 años después del inicio del cuadro, presentó limitación en la movilidad del cuello; presentando va-rios episodios de disfonía desde hace 10 años; al momento de la consulta la paciente presentó limitación de la movilidad del cue-llo y dolor cervical. La imagen de resonancia magnética reportó: presencia de crecimiento óseo anterior de los cuerpos vertebra-les, este hallazgo está en relación con el síndrome de Forestier. Conclusiones: Por ser una enfermedad poco conocida es sub-diagnosticada y a menudo confundida con otras patologías. Los pacientes son diagnosticados muchos años después de que apa-recieron los primeros síntomas que incluyen dolor, limitación de la movilidad, disfagia y dificultad respiratoria. El tratamiento incluye manejo sintomático, terapia física y manejo quirúrgico...(AU)

Meta-analysis of calcium chemotherapeutic effect of anterior cervical subtotal vertebroplasty and posterior laminoplasty / 中国骨伤

OBJECTIVE@#To systematically assess the efficacy of anterior cervical corpectomy and fusion (ACCF) versus posterior laminoplasty (LAMP) for cervical ossification of posterior longitudinal ligament (OPLL).@*METHODS@#PubMed and EMBASE, Cochrane Library, CBM, CNKI, Wanfang and VIP were collected from 7 databases of ACCF, LAMP from 1970 to May 2018. According to the criteria, the articles were included and independently screened by two authors. The quality of the articles was assessed by using the MINORS scale (methodological index for non randomized studies). After extracting the data from the article, the JOA score, cervical curvature, operation time, bleeding volume, excellent and good rate, recovery rate, adverse events and secondary surgery were analyzed by using Review Manager 5.3 software.@*RESULTS@#Finally, a total of 22 articles with 1 678 patients were included in this Meta-analysis, with 810 patients in ACCF group and 868 patients in LAMP group. Meta analysis results showed that the ACCF group had higher postoperative JOA scores[MD=0.63, 95%CI(0.05, 1.20), = 0.03], higher excellent rate [=1.85, 95%CI (1.14, 3.02), =0.01] and higher recovery rate [=11.90, 95%CI (5.75, 18.05), =0.000 1]. But the LAMP group has a shorter operative time [MD=52.19, 95%CI (29.36, 75.03), <0.000 01], less complications [=1.56, 95%CI (1.03, 2.35), =0.04] and less reoperations [=3.73, 95%CI (1.62, 8.57), =0.002]. There was no significant different in postoperative lordosis [MD=3.15, 95%CI(-0.14, 6.43), =0.06] and blood loss[SMD= 0.26, 95%CI(-0.05, 0.57), =0.10] between two groups.@*CONCLUSION@#The recovery of functionof ACCF group was better, but operation time, complications and reoperations of LAMP group were all better than ACCF group. There was no difference in postoperative lordosis and intraoperative blood loss between two groups. However, there are some limitations in this study. Therefore, higher quality and larger sample size clinical studies are needed to further verify.

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

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

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

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

Comparison of multi-mode and single-mode intraoperative neurophysiological monitoring in the treatment of severe ossification of the cervical posterior longitudinal ligament with anterior cervical corpectomy with fusion / 中国骨伤

OBJECTIVE@#To compare the application of multi-mode and single-mode intraoperative neurophysiological monitoring in the treatment of severe ossification of posterior longitudinal ligament of cervical spine with anterior cervical corpectomy with fusion.@*METHODS@#From April 2015 to June 2018, 32 patients with severe ossification of the posterior longitudinal ligament were treated in the Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine. There were 21 males and 11 females, aged 45 to 73 years old, with a mean age of 59 years old. The duration of the disease ranged from 6 to 72 months, with a mean of 39 months. The main manifestations were numbness, numbness and weakness of limbs, cotton feeling of foot stepping on lower limbs, instability of standing and walking. With the gradual aggravation of symptoms, quadriplegia, dysfunction of urine and defecation may occur. Patients with ossification of posterior longitudinal ligament of cervical spine were monitored by somatosensory evoked potentials, motor evoked potentials and electromyogram patterns.@*RESULTS@#During the operation, 8 patients had abnormal amplitude of somatosensory evoked potential(SEP); 5 of them had bleeding during anterior cervical decompression procedure and were placed with too much hemostatic cotton, which caused compression of spinal cord and resulted in abnormal SEP waveform. After removal of the hemostatic cotton, SEP waveform returned ot normal; 3 patients had abnormal SEP waveform due to decreased systolic pressure, which was corrected by increased systolic pressure. Twelve patients had abnormal amplitude of motor evoked potential during monitoring, 9 of which were caused by intraoperative mis-contact with nerve root, and turned to normal after timely adjustment of position, 3 of which were caused by intraoperative inhalation of muscle relaxant during surgery. Among 11 patients with abnormal EMG waveform, 9 patients recovered to normal waveform after adjusting operation, 2 patients recovered to normal waveform after short observation, and all patients recovered to normal waveform of motor evoked potential after operation(<0.05). There were 2 cases of cerebrospinal fluid leakage after operation, which healed spontaneously 7 days after operation, and no complications of spinal cord and nerve occurred in all patients after operation.@*CONCLUSIONS@#In anterior cervical corpectomy with fusion operation for the treatment of severe cervical ossification of posterior longitudinal ligament, various modes of intraoperative neurophysiological monitoring can real-time understand spinal cord and nerve function status, significantly reduce the incidence of spinal cord and nerve injury during operation, and effectively improve the safety of operation.

Progression of Ossification of the Posterior Longitudinal Ligament after Cervical Total Disc Replacement / 대한신경손상학회지

OBJECTIVE: Total disc replacement (TDR) is frequently performed anterior approaching method for the patients diagnosed with cervical disc herniation. This study aimed to assess the degree of ossification of the posterior longitudinal ligament (OPLL) progression after cervical TDR. METHODS: Twenty-two male soldiers who underwent cervical TDR surgery from 2009 to 2016 and were followed-up for more than 12 months were enrolled. The enrolled patients were classified as; 1) patients with pre-existing OPLL and without; and 2) patient showing progression of OPLL or not. RESULTS: Twenty-two men were included in the analysis. The mean follow-up period from the surgery was 41.4 months (range, 12–114 months). The mean age of all patients was 40.7 years (range, 31–52 years). TDR-only was used in 7 cases, and the hybrid surgery (TDR+ACDF) was used in 15 cases. The incidence of progression or newly development of OPLL was significantly higher in pre-existing OPLL group (p=0.01). In 11 cases showing the progression of the OPLL, the mean size of OPLL progression was 4.16 mm (range, 0.34–18.87 mm) in the longitudinal height and 1.57 mm (range, 0.54–3.91 mm) in thickness. CONCLUSION: The progression of OPLL after cervical TDR was more frequent in patients with pre-existing OPLL than in patients without OPLL. Even though TDR is a major alternative to the treatment of cervical lesions to preserve vertebral segmental motion, careful attention should be paid to whether TDR should be used in patients with OPLL and this should be fully explained to the patient.

Investigation of Symptomatic Unstable Changes of Non-Fused Component in the Mixed-Type Cervical Ossification of Posterior Longitudinal Ligament Using Dynamic Magnetic Resonance Imaging: A Case Report / 대한신경손상학회지

A 43-year-old man was transferred to our hospital with recurring myelopathic symptoms after previous anterior and posterior surgical decompressions for mixed-type cervical ossification of the posterior longitudinal ligament (OPLL). Conventional magnetic resonance imaging (MRI) showed a preserved cervical curve and the achievement of successful decompression after the previous surgeries. The patient's symptoms were aggravated when he was in the extended neck posture. Dynamic MRI performed with the patient in an extended neck position revealed cord compression by OPLL from C3 to C4 with newly developed retrolisthesis of the C4–5 segment. We recommend the use of dynamic MRI to investigate motion-dependent cord compression caused by instability of the non-fused OPLL component.

Analysis of Factors Contributing to Repeat Surgery in Multi-Segments Cervical Ossification of Posterior Longitudinal Ligament

OBJECTIVE: Cervical ossification of the posterior longitudinal ligament (OPLL) can be treated via anterior or posterior approach, or both. The optimal approach depends on the characteristics of OPLL and cervical curvature. Although most patients can be successfully treated by a single surgery with the proper approach, renewed or newly developed neurological deterioration often requires repeat surgery.METHODS: Twenty-seven patients with renewed or newly developed neurological deterioration requiring salvage surgery for multi-segment cervical OPLL were enrolled. Ten patients (group AP) underwent anterior approach, and 17 patients (group PA) underwent posterior approach at the initial surgery. Clinical and radiological data from initial and repeat surgeries were obtained and analyzed retrospectively.RESULTS: The intervals between the initial and repeat surgeries were 102.80±60.08 months (group AP) and 61.00±8.16 months (group PA) (p < 0.05). In group AP, the main OPLL lesions were removed during the initial surgery. There was a tendency that the site of main OPLL lesions causing renewed or newly developed neurological deterioration were different from that of the initial surgery (8/10, p < 0.05). Repeat surgery was performed for progressed OPLL lesions at another segment as the main pathology. In group PA, the main OPLL lesions at the initial surgery continued as the main pathology for repeat surgery. Progression of kyphosis in the cervical curvature (Cobb’s angle on C2–7 and segmental angle on the main OPLL lesion) was noted between the initial and repeat surgeries. Group PA showed more kyphotic cervical curvature compared to group AP at the time of repeat surgery (p < 0.05).CONCLUSION: The reasons for repeat surgery depend on the type of initial surgery. The main factors leading to repeat surgery are progression of remnant OPLL at a different segment in group AP and kyphotic change of the cervical curvature in group PA.

Analysis of Factors Contributing to Repeat Surgery in Multi-Segments Cervical Ossification of Posterior Longitudinal Ligament

OBJECTIVE: Cervical ossification of the posterior longitudinal ligament (OPLL) can be treated via anterior or posterior approach, or both. The optimal approach depends on the characteristics of OPLL and cervical curvature. Although most patients can be successfully treated by a single surgery with the proper approach, renewed or newly developed neurological deterioration often requires repeat surgery. METHODS: Twenty-seven patients with renewed or newly developed neurological deterioration requiring salvage surgery for multi-segment cervical OPLL were enrolled. Ten patients (group AP) underwent anterior approach, and 17 patients (group PA) underwent posterior approach at the initial surgery. Clinical and radiological data from initial and repeat surgeries were obtained and analyzed retrospectively. RESULTS: The intervals between the initial and repeat surgeries were 102.80±60.08 months (group AP) and 61.00±8.16 months (group PA) (p < 0.05). In group AP, the main OPLL lesions were removed during the initial surgery. There was a tendency that the site of main OPLL lesions causing renewed or newly developed neurological deterioration were different from that of the initial surgery (8/10, p < 0.05). Repeat surgery was performed for progressed OPLL lesions at another segment as the main pathology. In group PA, the main OPLL lesions at the initial surgery continued as the main pathology for repeat surgery. Progression of kyphosis in the cervical curvature (Cobb’s angle on C2–7 and segmental angle on the main OPLL lesion) was noted between the initial and repeat surgeries. Group PA showed more kyphotic cervical curvature compared to group AP at the time of repeat surgery (p < 0.05). CONCLUSION: The reasons for repeat surgery depend on the type of initial surgery. The main factors leading to repeat surgery are progression of remnant OPLL at a different segment in group AP and kyphotic change of the cervical curvature in group PA.

Analysis of clinical efficacy of unilateral open-door cervical laminoplasty combined with foraminotomy for cervical ossification of posterior longitudinal ligament / 中国骨伤

<p><b>OBJECTIVE</b>To explore the clinical efficacy of unilateral open-door laminoplasty combined with foraminotomy for cervical ossification of posterior longitudinal ligament(OPLL).</p><p><b>METHODS</b>The clinical data of 45 patients with OPLL underwent surgical treatment between September 2011 and September 2015 were retrospectively analyzed. There were 26 males and 19 females with a mean age of 53.6 years old(ranged from 28 to 71 years). Among them, 24 cases received the surgery of unilateral open-door cervical laminoplasty combined with foraminotomy(combined group), and 21 cases received a single unilateral open-door cervical laminoplasty(single group). Operation time, intraoperative blood loss, complications including C₅ nerve root palsy and axial symptoms were compared between two groups. Pre-and post-operative Japanese Orthopedic Association(JOA) score, improvement rate of neurological function, Neck Disability Index(NDI) score, and cervical Cobb angle were recorded and analyzed between the two groups.</p><p><b>RESULTS</b>All the patients were followed up for 12-24 months, with an average of (14.3±2.8) months for combined groups and (13.7±3.1) months for single group, and no significant difference was found between the two groups(>0.05). There was no significant difference in operation time and intraoperative blood loss between two groups(>0.05). Postoperative JOA scores obtained obvious improvement in all patients(<0.05). However, there was no significant difference between two groups for the improvement rate of neurological function(>0.05). At final follow-up, NDI scores of combined group and single group were 13.6±1.8 and 16.1±2.4 respectively, there was significant difference between two groups(<0.05). The incidence of C₅ nerve root palsy was lower in combined group(4.2%) than that of single group (28.6%). There was no significant difference in incidence rate of axial symptoms between two groups(>0.05). There was no significant difference in cervical Cobb angle between pre-and post-operative conditions, or between two groups(>0.05).</p><p><b>CONCLUSIONS</b>Unilateral open-door cervical laminoplasty combined with foraminotomy is an effective method to treat cervical OPLL, which could provide sufficient decompression of spinal cord and nerve root, prevent the C₅ nerve root palsy.</p>

Compressive Myelopathy Due to Ossification of the Ligamentum Flavum: Case Report and Review of the Literature

Ossification of the ligamentum flavum (OLF) is a rare condition in which the ligamentum flavum, due to mechanical, biological and genetic factors, becomes ossified. Due to its nature and anatomic location, OLF produces symptoms characteristic of spinal cord compression. The diagnostic confirmation is based primarily on imaging tests such as computed tomography (CT) and magnetic resonance imaging (MRI). Ossification of the ligamentum flavum most often affects Asian populations, rarely occurring in black people. The authors report a case of a 61-year-old black man with progressive paraparesis due to OLF, and review the literature regarding the pathology's prevalence, pathogenesis, clinical features, diagnosis, treatment and prognosis.

A ossificação do ligamento flavo (OLF) é uma doença rara na qual o ligamento flavo se torna ossificado devido a fatores mecânicos, biológicos e genéticos. Devido à sua natureza e localização anatômica, a OLF produz sintomas característicos de compressão da medula espinhal. A confirmação diagnóstica baseia-se principalmente em exames de imagem, como tomografia computadorizada (TC) e ressonância magnética (RM). A OLF afeta mais comumente populações asiáticas, raramente sendo observada em pacientes negros. Os autores relatam o caso de um homem negro de 61 anos com paraparesia progressiva decorrente de OLF com uma revisão da literatura a respeito da prevalência, patogênese, aspectos clínicos, diagnóstico, tratamento e prognóstico desta patologia.

Síndrome de Pellegrini-Stieda: más allá que un signo radiológico / Pellegrini-Stieda syndrome: More than a radiological sign

El signo de Pellegrini-Stieda es la calcificación del ligamento colateral medial de la rodilla posterior a trauma. La presencia de síntomas asociados a los hallazgos radiológicos se conoce con el nombre de síndrome de Pellegrini-Stieda. El dolor es el principal elemento caracterizador de la enfermedad. El tratamiento varía desde reposo, fisioterapia, uso de antiinflamatorios no esteroides, infiltración con glucocorticoides hasta cirugía, en casos severos y recalcitrantes

The Pellegrini-Stieda sign is a calcification of the medial collateral ligament of the knee after trauma. The presence of symptoms associated with radiological findings is known as Pellegrini-Stieda syndrome. Pain is the main element that characterises the disease. Treatment ranges from rest, physical therapy, use of nonsteroidal anti-inflammatory drugs, glucocorticoid injection, and even surgery in severe and recalcitrant cases

Application of 360 degree circular decompression and transpedicle screw fixation in the treatment of ossification of thoracic posterior longitudinal ligament by posterior approach / 中国骨伤

<p><b>OBJECTIVE</b>To investigate the clinical effects of 360 degree circular decompression and transpedicle screw fixation to treat the ossification of thoracic posterior longitudinal ligament by posterior approach.</p><p><b>METHODS</b>From December 2009 to November 2013, 18 patients with ossification of thoracic posterior longitudinal ligament ossification were treated with 360 degree circle decompression and transpedicle screw fixation by posterior approach. There were 8 males and 10 females,ranging in age from 32 to 67 years old, with an average of 51 years old. Four patients were accompanied with ligamentum flavum ossification. Longitudinal ossifications in 5 cases were located in the upper thoracic vertebra and 13 cases in the middle and lower thoracic vertebra. Five cases were typical type, 4 cases were segmental type, 6 cases were continuous type and 3 cases were mixed type. All the patients had the posterior spinal canal decompression combined with longitudinal ligament resection, interbody fusion with bone graft and internal fixation surgeries. The operation time,blood loss and complications were recorded. JOA score were applied to evaluate the neurological function recovery pre-surgery, 2 days post-surgery and the latest follow-up. The surgery effects were evaluated by Epstein-Schwall method.</p><p><b>RESULTS</b>The operation time ranged from 3 to 6 hours (mean, 4.2 hours). The blood loss ranged from 800 to 4 000 ml (mean, 1 800 ml). All the patients were followed up, and the duration ranged from 6 months to 3 years, with a mean of 1.8 years. The JOA score increased from preoperative 4.30 ± 2.60 to 7.60 ± 2.40 2 days after surgery, and 7.80 ± 1.90 at the latest follow-up (t = 4.61, P < 0.001). The JOA scores between 2 days after surgery and the latest follow-up had no significant differences (t = 0.28,P = 0.78). The neurological recovery rate was 74% 2 days after surgery and 71% at the latest follow-up. There were 4 cases got an excellent result,10 good,3 fair and 1 poor according to Epstein-Schwall evaluation method. Four patients had cerebrospinal fluid leakage, 3 patients had intercostal nerve paralysis or pain, and 1 patient had superficial incision infection. The neurological function in 3 patients became worse in the second day posteratively , and among them, 2 patients were recovered at the latest follow-up and 1 patient had no changes. All the patients got fusion of bone graft and no internal fixation loosening and fractures occurred.</p><p><b>CONCLUSION</b>360 degree circular decompression and transpedicle screw fixation can resect different types of thoracic longitudinal ligament ossification, and can achieve a good clinical effect.</p>

Cauda Equina Syndrome due to Lumbar Ossification of the Posterior Longitudinal Ligament: A Case Report

STUDY DESIGN: A case report. OBJECTIVES: To report a rare case of cauda equina syndrome due to lumbar ossification of the posterior longitudinal ligament (OPLL). SUMMARY OF LITERATURE REVIEW: Lumbar OPLL with neurologic symptoms is very rare. MATERIALS AND METHODS: A 49-year-old female had experienced weakness in both lower extremities and radiating pain for 1 day prior to presentation. Simple radiography and CT showed OPLL at the L1-L2 level. We performed a total laminectomy and posterolateral fusion at the L1-L2 level using a posterior approach. RESULTS: After treatment, the patient showed improvement of symptoms and is currently living without discomfort. CONCLUSIONS: Cauda equina syndrome due to lumbar OPLL is rare; however, rapid neurologic recovery can be achieved through early diagnosis and surgery.

Increased Prevalence of Ossification of Posterior Longitudinal Ligament and Increased Bone Mineral Density in Patients with Ossification of Nuchal Ligament

OBJECTIVE: There are also few studies demonstrating the relationship between ossification of nuchal ligament (ONL) and ossification of posterior longitudinal ligament (OPLL). We compared the prevalence, location, and type of OPLL between patients with ONL and matched patients without ONL.We also compared the bone mineral densities (BMDs) between the 2 groups. METHODS: total of 124 cervical ONL patients were enrolled in this study. The control group of 124 patients was matched with 124 patients with ONL by age and sex on a 1:1 basis to minimize confounding factors. We reviewed the prevalence, location, and type of OPLL in both groups. RESULTS: The prevalence of OPLL was almost 2.5 times greater in patients with ONL than those without ONL. The mean value of BMD in patients with ONL was greater at the lumbar spine (L1-L4) than in patients without ONL. The mean T score of the lumbar spine was 0.25±1.68 in the patients with ONL and -0.73±1.64 in the patients without ONL. CONCLUSION: The prevalence of OPLL in patients with ONL was significantly higher than in patients without ONL. Because ONL is innocuous and may be seen more readily than OPLL on simple cervical radiographs, clinicians should consider the possibility of coexisting OPLL when ONL, especially extensive ONL, is detected in patients with neck pain, radiculopathy, or myelopathy, to facilitate proper treatment.

Posterior Trans-Dural Repair of Iatrogenic Spinal Cord Herniation after Resection of Ossification of Posterior Longitudinal Ligament

Iatrogenic spinal cord herniation is a rare complication following spinal surgery. We introduce a posterior trans-dural repair technique used in a case of thoracic spinal cord herniation through a ventral dural defect following resection of ossification of the posterior longitudinal ligament (OPLL) in the cervicothoracic spine. A 51-year-old female was suffering from paraplegia after laminectomy alone for cervicothoracic OPLL. Magnetic resonance imaging revealed a severely compressed spinal cord with pseudomeningocele identified postoperatively. Cerebrospinal fluid leak and iatrogenic spinal cord herniation persisted despite several operations with duroplasty and sealing agent. Finally, the problems were treated by repair of the ventral dural defect with posterior trans-dural duroplasty. Several months after surgery, the patient could walk independently. This surgical technique can be applied to treat ventral dural defect and spinal cord herniation.

A Comparison of Implants Used in Double Door Laminoplasty : Allogeneic Bone Spacer versus Hydroxyapatite Spacer

OBJECTIVE: The aim of this study was to compare the clinical and radiological outcomes associated with the use of hydroxyapatite (HA) spacer and allogeneic bone (AB) spacer in laminoplasty. METHODS: From January 2006 to July 2014, 79 patients with cervical spondylotic myelopathy or ossification of the posterior longitudinal ligament underwent cervical laminoplasty. The radiologic parameters were obtained from plain radiography and three-dimensional computed tomography. All images were taken before and after surgery. Cervical lordosis, spinal canal dimension, fusion between lamina and spacer, and resorption of spacer were checked. Clinical outcomes were assessed using visual analog scale and Japanese Orthopedic Association. RESULTS: Double-door laminoplasty was performed on 280 levels : 182 in the HA group and 98 in the AB group. The mean follow-up was 23.1 months (range : 4–69 months). Similar fusion rates were found in these groups (p=0.3). The resorption rate between lamina and spacer was lower in the HA group (p<0.001). During the immediate postoperative period, the canal dimension of both groups increased compared with the results in the preoperative period. However, the canal dimension of the AB group decreased over time compared with that of the HA group (p<0.001). CONCLUSION: Double-door laminoplasty improved the clinical outcomes of both groups. However, the spinal canal dimension in the AB group showed a greater degree of reduction than in the HA group at the final postoperative follow-up. Therefore, we suggest that surgeons consider the use of larger-sized AB spacers in double-door laminoplasties.

Repair of Inaccessible Ventral Dural Defect in Thoracic Spine: Double Layered Duraplasty

We propose a double layered (intradural and epidural patch) duraplasty that utilizes Lyoplant and Duraseal. We examined a 47-year-old woman after decompression for thoracic ossification of posterior longitudinal ligament was performed in another hospital. On postoperative day 7, she complained of weakness in both legs. Postoperative magnetic resonance imaging (MRI) showed cerebrospinal fluid (CSF) collection with cord compression. In the operative field, we found 2 large dural defects on the ventral dura mater. We performed a conventional fat graft with fibrin glue. However, the patient exhibited neurologic deterioration, and a postoperative MRI again showed CSF collection. We performed dorsal midline durotomy and inserted a intradural and epidural Lyoplant patch. She immediately experienced diminishing back pain postoperatively. Her visual analog scale and motor power improved markedly. Postoperative MRIs performed at 2 and 16 months showed no spinal cord compression or CSF leakage to the epidural space. We describe a new technique for double layered duraplasty. Although we do not recommend this technique for all dural repairs, double-layered duraplasty may be useful for repairing large inaccessible dural tears in cases of persistent CSF leakage refractory to conventional management.