OPLL颈椎后纵韧带骨化课件整理.ppt

1、.1OPLL经典综述讲读经典综述讲读王雪鹏王雪鹏杭州市骨科研究所杭州市骨科研究所杭州市第一人民医院骨科杭州市第一人民医院骨科.2.3.4.5.6Ossification of the posterior longitudinal ligament(OPLL)results from pathologic replacement of the PLL with lamellar bone,potentially causing spinal cord compression and neurologic deteriorationOPLL was first described in Japan

2、ese patients and has classically been considered a cause of myelopathy in patients of East Asian origin.7spondylosismyelopathyradiculopathystenosisdisc herniation.8.9Among patients in Japan with cervical spine disorders,the incidence has been estimated at 1.9%to 4.3%and,in other Asian countries,up t

3、o 3.0%OPLL has been recognized as an etiology of myelopathy regardless of ethnicity,with an estimated incidence rate of 0.1%to 1.7%among North Americans and Europeans.10PathoanatomyThe PLL runs along the dorsal surface of the C1 anterior arch and cervical vertebral bodies and consists of longitudina

4、l fibers confluent with the tectorial membrane cranially and ending at the sacrum caudallyfunctionally,the PLL resists spine hyperflexion.11PathophysiologyThe pathologic process leading to OPLL begins with chondroblast-and fibroblast-like spindle cell proliferation,along with vascular infiltration l

5、eading to PLL degeneration and hypertrophy.Endochondral ossification follows,resulting in its replacement with mature lamellar boneGenetics,local tissue characteristics,and associated medical comorbidities have all been implicated in this final common pathway.12.13Medical comorbidities are also asso

6、ciated with the development of OPLLUp to 50%of Caucasian patients with OPLL also have diffuse idiopathic skeletal hyperostosisHypoparathyroidism,hypophosphatemic rickets,hyperinsulinemia,and obesity have been identified as risk factors.14Natural HistoryPatients with OPLL commonly present in their fi

7、fth and sixth decades,with men affected twice as often as women.Most patients have some neurologic symptoms at diagnosis,with 28%to 39%fulfilling diagnostic criteria for myelopathy.15.16In patients with myelopathy,64%had deteriorated,however,and 89%of patients with Nurick grade 3 or 4 myelopathy who

8、 refused surgery had progressed to a wheelchair-or bed-bound state.17Risk factors for the development of myelopathy include 60%spinal canal stenosis,6 mm of space available for the cord,increased cervical range of motion,and OPLL that is laterally deviated within the spinal canalAge,gender,and the n

9、umber of levels affected by OPLL do not affect the prognosis.18Clinical PresentationChanges in gait or balance,loss of fine motor control,and upper extremity weakness,numbness,or paresthesias are suggestive of myelopathyEarly muscular fatigue or worsening symptoms at the extremes of cervical motion

10、are also concerning.19Patients with OPLL are at an increased risk of acute spinal cord injury with trauma,and rapid neurologic deterioration in association association with even a minor trauma or whiplash injury should raise concern for the development of central cord syndrome.20Physical Examination

11、.21Radiologic Evaluation.22The lateral radiograph is also used to determine the relationship of the OPLL to the kyphosis line(K-line),which is drawn from the center of the canal at C2 to the center of the canal at C7A large OPLL mass or loss of cervical lordosis causes the OPLL to protrude posterior

12、 to the K-line(referred to as K-line negative).This is a negative prognostic factor for posterior surgery alone.23.24CT with sagittal and coronal reformatting has emerged as the benchmark for radiographic evaluation of OPLL and is necessary to reliably characterize it.25Greater than 60%canal occupan

13、cy at any level and a laterally deviated mass are associated with high rates of myelopathyThis“double layer sign”on axial or sagittal CT images is associated with dural tear rates 50%with anterior decompression versus 13%when the sign is absent.26.27Nonsurgical ManagementProphylactic surgery is neit

14、her necessary nor recommended Management includes temporary immobilization with a neck brace,steroidal or nonsteroidal anti-inflammatory medications,activity modification,and physical therapy.28patients should be advised to avoid activities that may result in sudden or excessive cervical spine motio

15、n because OPLL is associated with a high rate of acute spinal cord injury,even in patients who do not meet surgical criteria.29Surgical TreatmentSurgical decompression is the treatment of choice for patients with Nurick grade 3 or 4 myelopathy or severe radiculopathy caused by OPLL via either an ant

16、erior or posterior approach.30Anterior Decompression and FusionProponents argue that it allows for a superior decompression and is more effective at maintaining or restoring cervical lordosis than is posterior surgery.Associated anterior pathology,such as disk herniations,can also be addressed.31Dis

17、advantages include technical difficulty,inability to decompress cranial to C2,and high rates of pseudarthrosis and dysphagia when three or more levels require treatment Dural tears are also much more common with an anterior approach,given that anterior dural ossification occurs in 13%to 15%.32Exposu

18、re is provided by the standard Smith-Robinson approach,and diskectomy,hemicorpectomy,or subtotal corpectomy sufficient to allow exposure of the underlying OPLL mass is performedCorpectomies of up to five levels have been performed with success,but removal of three or more contiguous levels is associ

19、ated with increased complication and reoperation rates.33Complications occur as part of the approach(eg,dysphagia,dysphonia),the decompression(eg,C5 palsy,dural tears),or the fusion(eg,graft subsidence,pseudarthrosis).34Nerve root palsies occur in 4%to 17%of patients through either direct trauma or

20、traction.Patients present with weakness,numbness,pain,or paresthesias,most commonly in the C5 distribution.35Dural tears occur in 4%to 20%of patients,often because of dural ossification or attenuation.Cerebrospinal fluid leakage may result in pseudomeningocele or fistula formation,leading to neural

21、damage,airway compression,meningitis,or wound complications.36Tears recognized intraoperatively are treated by direct repair or by application of autogenous fascial or synthetic collagen grafts.Closure of pinhole defects or augmentation of repairs is done with thrombogenic sealants,such as fibrin gl

22、ue or gelatin foam.Postoperatively,diverting lumbar drains and bed rest can be used.37 In an effort to reduce dural tear rates,Yamaura et al introduced the“anterior floating method”for cervical decompression,consisting of subtotal vertebral body resection and thinning,but not removal,of the OPLL.The

23、 posterior vertebral body is not reconstructed,allowing the OPLL to“float”anteriorly and away from the spinal canal.At 5-year follow-up,the authors achieved a mean recovery rate of 68.5%and improvement in Japanese Orthopaedic Association scores from 8.3 to 14.2.No leaks of cerebrospinal fluid occurr

24、ed,but 14%of patients were left with an inadequate decompression.In these patients,or with OPLL progression,the authors recommended subsequent posterior decompression.38 When addressing more than two or three levels,fibular strut grafts are preferred for their structural support.For one or two level

25、s,structural grafts of tricortical iliac crest,fibula,and vertebral bodies have all been described.More recently,interbody cages with nonstructural bone graft or bone graft substitutes have been used.Overall rates of pseudarthrosis vary from 3%to 15%,with the highest rates occurring in patients unde

26、rgoing fusion of three or more levels.39.40.41.42.43.44Posterior DecompressionWhen more than two or three cervical levels are affected by OPLL,posterior surgery(ie,laminoplasty,or laminectomy and fusion)is preferred because of the technical ease and lower rate of complications.Disadvantages include

27、the risk of postoperative disease progression,inability to correct cervical kyphosis,and poor results in K-line negative patients.45Laminoplasty accomplishes this by hinging open the laminae with either an“open door”or“French door”technique,resulting in a 30%to 40%increase in the size of the spinal

28、canalLaminectomy and fusion entails removal of the laminae followed by instrumented posterolateral fusion,resulting in a 70%to 80%increase in canal volume.46.47.48.49.50.51.52.53A full analysis of the advantages and disadvantages between laminoplasty compared with laminectomy and fusion has been dis

29、cussed elsewhereOur preference is to use laminectomy and fusion for OPLL because the retained cervical motion with laminoplasty may allow disease progression,and the risk for progression to kyphosis at the affected levels is eliminated with fusion.54For severe disease,recovery rates after posterior

30、decompression appear to be lower than those following anterior decompression,but with a lower complication rate.55Iwasaki et al retrospectively compared the results of anterior decompression and fusion with those of laminoplasty;they reported better outcomes after anterior surgery in patients with a

31、n OPLL mass occupying 60%of the canal;however,it results in a reoperation rate of 26%versus 2%in the laminoplasty group.With60%canal occupancy,recovery rates were equivalent.56 A prospective comparison of anterior decompression and fusion versus laminoplasty found similar results.Patients with 50%ca

32、nal occupancy had superior recovery rates with anterior surgery but equivalentrates with 50%involvement Patients with 5of cervical lordosis also had significantly worse outcomes from laminoplasty,and 50%lost lordosis versus none in the fusion group.Half of the laminoplasty patients experienced OPLL

33、progression versusonly one after anterior surgery However,surgical complications heavily favored laminoplasty,with a 23%complication rate and a 14%reoperation rate in the anterior group and none in the laminoplasty patients.57 Only one study to date has examined the results of laminectomy and fusion

34、 for OPLL.58Chen et al reported a mean recovery rate of 62%at 5 years among 83 patients who underwent instrumented laminectomy and fusion from C2 or C3 to C7.Patients with a good outcome had significantly more postoperative lordosis(16.1 versus10.4).No other factors,including occupying ratio,were si

35、gnificant between groups.The reoperation rate was 4%,all the result of epidural hematoma formation.Whether posterior fusion had an effect on disease progression was not evaluated,although the authors noted no longterm decline in neurologic recovery,as is commonly seen in laminoplasty patients.59.60.

36、61The most common complication of posterior surgery is low cervical nerve root palsy,which occurs in 4%to 12%of patients.Injury may occur from direct trauma or from traction neurapraxia as the cord migrates posteriorlyComplications specific to laminoplasty include closure of the laminoplasty and fra

37、cture of the laminar hinge,whereas laminectomy and fusion may be complicated by hardware failure,pseudarthrosis,or a post-laminectomy membrane.62Both procedures can be complicated by chronic pain,loss of lordosis,epidural hematoma,and progression of disease.63Combined Anterior andPosterior Decompres

38、sionWhen the disease involves more than three levels,however,the addition of a posterior decompression allows the remainder of the cervical spine to be addressed while avoiding a multilevel anterior dissection Posterior instrumentation may also be used to increase the stability of an anterior construct and promote fusion Finally,late posterior surgery may also be preferable to revision anterior surgery in the event of disease progression or pseudarthrosis.64.65.66.67Take Home Messages.68Thank You!