Experiment Of Spinal Canal Volume Change And The Clinical Research After Cervical Minimally Invasive Lamionplasty

BACKGROUND AND OBJECTIVECervical spondylotic myelopathy (CSM) is based on the cervical intervertebral disc degeneration, on this basis, appear the cervical intervertebral disc herniation、 vertebral rear osteophyte、posterior longitudinal ligament ossification、 facet joint degeneration and hyperplasia、 yellow ligament hyperplasia ossification and so on. More than one or several factors participate in the cervical spinal canal stenosis, causeed the blood vessel that around spinal cord or spinal cord compression, eventually lead to different degrees of spinal cord and nerve dysfunction。 The main Clinical manifestations of CSM are the neck and shoulder discomfort、numbness、 trunk"belted"sense、 walking instability、 the lower limbs feeling stepped on cotton、 tendon reflex hyperfuncion、 muscle atrophy, even severe cases can lead to paralysis。 CSM is the most serious type of cervical spondylosis, accord for5%-10%of cervical spondylosis, occurs in the olderly people over50, its incidence of occult, clinically rare in a long-term stable phase,70-80%of the performance was chronicprogressive deterioration, and with high morbidity, is threatening the health of elderly patients with common diseases,Therefore, many advocate aggressive treatment measures before irreversible damage in the spinal cord function。 Most scholars believe that within three to six months onset of treatment, can achieve good spinal cord function recovery,the short course of the disease, the better results。At present, there are many theropy methods about CSM,consider with the disease severity, can be divided into non-surgical therapy and operation therapy; from the surgical approach, can be divided into cervical anterior and posterior treatment。 Due to individual difference in the clinical manifestations of the CSM,each hold their own views on the treatment of the disease, especially in multilevel CSM,current treatment multiple segmental CSM to majority of cervical posterior approach。 Can directly deal with compression factors such as the yellow ligament thickening、 small joint hyperplasia and so on, but also by expanding vertebral canal, so the spinal cord backward use "bowstring"principle.to indirect deal with the front compression factors of spinal cord.posterior surgery including laminectomy or semi-lainectomy、 laminoplasty, posterior laminectomy due to damage the important structure of cervical such as lamina、facet joint, the Integrity of cervical spinal canal loss, lead to high incidence of postoperateive complications, like cervical instability、 deformity of Inflection、iatrogenic oppression。At present laminectomy has been replaced by cervical laminoplasty.single-door and double-door of posterior cervical laminopalsry are now the main methods to treat cervical spondylotic myelopathy(CSM),but they all have the same question that with the spinous process ligament complex damaged, even completely resected and affect the curative effect. So we puts forword cervical minimally invasive laminoplasty, to observe the canal volume expansion and analyse the effect of decompression and curative effect.METHODStook12dry specimens of the fifth cervical vertebra to simulate cervical minimally invasive laminoplasty, self-control before and after surgerys, divided into control and experimental groups (including three groups that with bilateral plate long strip slotted、spinous and vertebral plate retruded by1mm、2mm、3mm), the specimens were thin-slice scanned with spiral CT,measured the volume of bony cervical canal with the3D tools in CT workstation respectively. Selected46CSM patients received cervical minimally invasive laminoplasty from9th2010to9th2011in our department,.according toJapanese Orthopaedic Association (JOA) scoring system, neurologic function were evaluated before and after surgery through self-control.RESULTSabout the12dry specimens of the fifth cervical vertebra, average cervical bony spinal canal volume of their the control group was1592±331mm3,,average cervical bony spinal canal volume of concessions1mm、2mm、3mm were respective1727±357mm3、1861、386mm3、2001±416mm3;the improvement rate of the capacity were respective8.53、1.05%、16.93±1.78%、25.75±2.97%, the concessions2mm group compared with lmm group, p<0.05,it had the statistical significance,the3mm group compared with the2mm group, p<0.05,it had the statistical significance,the3mm group compared with the lmm group, p<0.05,it had the statistical significance, patiens group:the average surgery time was75minutes (50-105),and the average amount of bleeding was375ml (300-450),the JOA score was7.97±1.73before surgery and was13.14±1.74in final followed-up,the JOA score improvement rate was58.55±13.71%,the excellent and good rates were obtained in83.3%(9excellent,21good,6fair). Specimens simulation can better reflect the spinal canal volume of cervical minimally invasive lamionplasty, provides a reliable basis for guiding effective decompression.CONCLUSIONSpecimens simulation can better reflect the spinal canal volume of cervical minimally invasive lamionplasty, provides a reliable basis for guiding effective decompression.