Effect Of Intervertebral Height With Single-level Cervical Fusion On Adjacent-level Intervertebral Discs

ObjectiveTo investigate the effect of intervertebral height with single-level cervical fusion on adjacent-level intervertebral discs.Methods73 patients(31women and 42men) with single-level cervical spine fusion in our hospital were investigated.The average age is 52 years old.They all had been followed-up one year at least and had complete information.All the full flextion and extention lateral radiographs of cervical spine were measured.According to the change of intervertebral height with single-level cervical fusion,they were devided into increased group,diminished group and no changed group.Intervertebral height, angle and shift of adjacent-level intervertebral disc were measured,including pre-operate,three months after operate,one year after operate and two year after operate.Then observe if heterotopic ossification formed in adjacent-level intervertebral disc of all patients.ResultsCompare with pre-operative data,intervertebral height,angle and shift of up-level intervertebral disc at one year and two years after the surgery of all patients are different,and has statistical meaning(P＜0.05).The difference between pre-operative and three months after the surgery has no statistical meaning(P＞0.05).The up-level intervertebral discs at one year and two years after the surgery have a distinct degeneration,and they are more severe as time extent. Pre-operatively intervertebral height of three groups have no statistical distinction;at three months after the surgery there is no statistical distinction,;one year after the surgery there is statistical distinction between diminished group and no changed group,and no statistical distinction between increased group and no changed group; two year after the surgery there is statistical distinction between diminished group or increased group and no changed group.Angle of up-level intervertebral disc of three groups have no statistical distinction preoperatively and at three months,one year after the surgery;two year after the surgery there is statistical distinction between no changed group and diminished group or increased group.Shift of up-level intervertebral disc of three groups have no statistical distinction preoperatively and at three months,one year after the surgery;two year after the surgery there is statistical distinction between no changed group and diminished group or increased group. Diminished group and increased group both have a higher rate of ossification than no changed group,and have statistical meaning;there is no statistical distinction between diminished group and increased group.ConclusionsAnterior cervical discectomy and fusion(ACDF) has been used to treat cervical degenerative diseases for many years clinically,and now it is the most sucessful surgery.But there are still a few problems theoretically or have emerged.According to abundant index of X-ray,this article is to investigate the effect of intervertebral height with single-level cervical fusion on adjacent-level intervertebral discs. Single-level cervical fusion leads to degenation of adjacent-level intervertebral disc, but the intervertebral height postoperative which regains its normal height will have slower degeneration,increase and diminish both accelerate the degenation of adjacent-level intervertebral discs.Therefore,the recovery of intervertebral height after fusion can defer the degenation of adjacent-level intervertebral discs,and raise the long-term curative effect of surgery.