| Part1Correlation study of the degree of spinal cord compression andintramedullary increased signal intensity on ossification of theligamentum flavum patientsObjective: With the development of medical examination technology andequipment, magnetic resonance imaging (MRI) and computerized tomography(CT) have been used in clinical examination in recent years. So more andmore patients who had ossification of the ligamentum flavum (OLF) could bediagnosed clearly. In slight stenosis cases, patients usually without any clinicalsymptoms. However, after the ossified tissues increased gradually, theneurological condition could become deteriorate when it can not tolerate theserious compression. The MRI, especially the whole spine MRI, given aaccuracy position for the thoracic ossification of the ligamentum flavum, andthe intramedullary increased signal intensity (ISI) can also be detect in th T2weighted image.In our study, we want to analysis the correlation between the degree ofspinal cord compression and the occurrence of ISI in the sagittal image, and toexplore if certain correlation was exist between them.Methods: From October2010to September2012, a total of92cases ofOLF patients were clearly diagnosed by the1.5T MR image, and they weredivided into3groups (group A, B and C) according to the degree of spinalcord compression. The neurological condition and intramedullary ISI wererecorded and analyzed respectively.Results: six patients who with ISI were in group A (20.7%),17cases werein group B (47.2%) and19cases were in group C (70.4%), there was significant statistical difference between the three group (P <0.05). TheJapanese Orthopedic Association (JOA) scale was7.1±2.1in group A,6.0±1.8in group B and5.6±2.0in group C, the difference being significant (P<0.05).After a further comparison, group A had significant difference with the groupB and C(P<0.05). However, no significant difference exist between group Band C (P＞0.05). The JOA score was5.4±1.8in the ISI patients and7.5±2.3inthe normal intensity patients, there was significant statistical differencebetween the two group (P <0.05).Conclusion: In OLF patients, the more severe the spinal cord beingcompressed, the more likely the ISI appeared. Moreover, the ISI patients havea lower JOA score and a longer disease course, which indicate a severe nervedamage. Part2The clinical effective of substep laminectomy and internal fixationin the treatment of multi-level of ossification of the ligamentum flavumObjective: The posterior laminectomy and spinal decompression as oneof the most prevalent methods has significant effect in the treatment ofmulti-level of ossification of the ligamentum flavum(M-OLF). In recent years,accompanied with the clinical application of high speed burr and thin bladeosteotome, laminar shelling decompression and Lamina osteotomy andreplantation with miniplate fixation as the new surgical technical had appliedin clinical to treat M-OLF. Each surgical procedure has its own characteristicsand accompanied by a variety of inadequacies. The en bloc resection oflaminae usually has the complications of dural tear, cerebrospinal fluidleakage and neurological deterioration. The multi-level laminectomy tends tooccurring segmental instability and local kyphosis. Lamina osteotomy andreplantation with miniplate fixation is relative complex, and has no ideal devices to fixation the replanted laminae, so the mini-plate is prone to loosingin the long term follow-up.In response to these problems, we attempted to treat M-OLF by theprocedure of substep laminectomy and internal fixation. The pedicle screwfixation combined bone graft between the transverse process could maintainthe stability for the decompression area. Besides, substep laminectomy couldreduce the risk of cerebrospinal fluid leakage.Methods: A retrospective study was performed in15patients who hadmulti-level of ossification of the ligamentum flavum received the procedure ofsubstep laminectomy and internal fixation, in which the laminae weredecompressed step by step until the spinal cord was fully smooth, and then thepedicle screw fixation combined bone graft between the transverse processwas done. There were6male and9female patients ranging from41-69years(mean,55.7years). The ossified ligamentum flavum involved two segments in2patients, three segments in10cases and four segments in3cases. Theneurological improvement and sagittal alignment changes postoperativelywere recorded and analyzed.Results: All patients were successfully being operated. After a average34.4-month follow-up, the mean score according to the Japanese OrthopedicAssociation (JOA) scale improved from5.8±1.7preoperatively to8.9±2.4at3months after the operation and9.3±2.5at the final follow-up (P＜0.01), with amean recovery rate of67.3%±15.2%. The Cobb angle decreased from15.9°±4.1°preoperatively to13.3°±3.7°at3months after the operation and14.0°±3.8°at the final follow-up (P＜0.05), the local kyphotic in the treatedarea decreased by1.9°±0.7°. No patient required additional surgery due tospinal canal re-obstruction and progressive spinal deformity. Cerebrospinalfluid leakage occurred in4patients, and healed well after being repaired. Alung infection and a deep vein thrombosis occurred in1patient respectively,and they were safely discharged after a regular treatment.Conclusion: substep laminectomy and internal fixation is an effectivetherapeutic option for thoracic myelopathy due to multilevel OLF compression, it not only provide an adequate decompression and a stabilized sagittalalignment, but also reduce the incidence of cerebrospinal fluid leakage. Part3Clinical Results and intramedullary signal changes of posteriordecompression with transforaminal interbody fusion for thoracicmyelopathy caused by combined ossification of the posterior longitudinalligament and ligamentum flavumObjective: Surgical treatment for thoracic myelopathy caused byossification of the posterior longitudinal ligament (OPLL) and ossification ofthe ligamentum flavum (OLF) has been recognized as technically demandingand results tend to be unfavorable. Until now, various operative approachesand treatment strategies have been attempted to conquer this problem, and theprocedure of posterior decompression with transforaminal thoracic interbodyfusion (PTTIF) may be the optimal tactic to treat the anterior–posteriorcompression in one step. It is comparatively less traumatic and with lessserious complications.Methods: Sixteen patients (seven men and nine women) with thoracicmyelopathy due to concurrent OLF and OPLL at the same level underwentPTTIF. We investigated the clinical outcomes and neurological improvement.Magnetic resonance imaging (MRI) was performed on all patientspreoperatively and postoperatively, and the intramedullary signal changeswere observed and evaluated..Results: The mean operating time was275minutes, and the meanoperating bleeding amount was1031mL. Cerebrospinal fluid leakage occurredin three patients, and healed well after being repaired. Neurological symptomdeterioration occurred in one patient, but the patient recovered nearly to thepre-operative level after methylprednisolone ictus treatment. The follow-up period ranged from28to47months. The mean score according to theJapanese Orthopedic Association (JOA) scale improved from4.3±1.2preoperatively to7.3±1.7at3months postoperation to8.5±1.5at the finalfollow-up (P <0.01), with a recovery rate of63.6%±20.0%. Postoperativeimages showed a significant improvement in the local kyphosis (P <0.01).Eleven patients (68.8%) showed increased signal intensity (ISI) onT2-weighted MRI preoperatively. At the final follow-up, the intramedullaryISI totally recovered in five patients. Neurological improvement was worse inpatients who had persistent ISI than the other patients (P <0.05).Conclusion: PTTIF is an effective therapeutic option for combinedOPLL and OLF, which provides satisfactory neurological recovery andstabilized thoracic fusion through a single posterior approach. Theintramedullary signal change does not always indicate a poor prognosis; onlythe irreversible ISI correlates with a poor clinical result. |
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