Therapeutic Efficacy And Biomechanical Study Of The Lower Cervical Fracture And Dislocation

Part 1 The biomechanical study on the stability of the lower cervical spine with facet joint capsule and posterior transarticular facet screw fixationObjective: This study intends to analyze the biomechanical test result of the lower cervical facet joint capsule and transarticular facet screw fixation of the lower cervical facet,and to verify and evaluate the effect of the lower cervical facet joint capsule and transarticular facet screw fixation technology on the stability of the lower cervical spine.In order to provide a theoretical basis of the treatment of lower cervical facet dislocation and the lower cervical instability.Methods: Twelve adult goat cervical specimens(C2-C7)were used.Removed all soft tissues such as muscles from the specimens,complete reserved each ligament structure of all specimens and the integrity of the facet joint capsules.The specimens were divided into A and B groups after preparation.The specimens of group A were resected one-sided facet joint capsule at the level of C4-C5.The specimens of group B were resected both sides of the specimens at the C4-C5 level.The preparation of specimens of both groups A and B was performed after the completion of the biomechanical experiment of complete lower cervical spine specimens.After the completion of the biomechanical experiments of groups A and B,the unilateral and bilateral transarticular facet screw-fixed specimens were prepared by implanting transarticular facet screws at the facet joints where the facet joint capsule was resected.Insertion of transarticular facet screws were performed by the same surgeon using the Klekamp method.Each group of specimens was subjected to vertical compression and lateral bending load tests in the front,rear,left,and right directions to obtain load-displacement curve results.Results: After the unilateral excision or injury of the lower cervical facet joint capsule,the stability of the cervical vertebra is not obvious.However,the bilateral cervical facet joint capsules excision or injury will have a significant impact on the stability of the cervical spine.Transarticular facet screw fixation can provide good biodynamics and stable internal fixation,transarticular facet screw fixation technology can be effectively used for surgical treatment of unstable lower cervical spine.Conclusion: The lower cervical facet joint capsule plays an important role in maintaining the stability of the lower cervical spine.Bilateral facet joint capsule injury can cause instability of the lower cervical spine or even fracture and dislocation of the lower cervical facet.The lower cervical transarticula screw fixation technology has the advantages of simple operation,high safety factor,and high holding force and pull-out resistance.Therefore,the transarticular facet screw fixation technology can be widely used in the surgical treatment of lower cervical instability caused by various reasons,especially cases with severe osteoporosis or congenital malformation.Part 2 Immediate reduction under general anesthesia and combined anterior and posterior fusion in the treatment of lower cervical facet dislocationObjective: Lower cervical facet dislocation is a sever traumatic lesion,frequently resulting in paralysis.The optimal surgical treatment is controversial.It has been a challenge for orthopedic surgeons to manage lower cervical facet dislocation while avoiding the risk of iatrogenic damage.Thus,safer strategies need to be designed and adopted.This study aimed to evaluate the clinical efficacy of immediate reduction under general anesthesia and combined anterior and posterior fusion in the treatment of lower cervical facet dislocation,provide theoretical basis for clinic.Methods: Twenty-four subjects of traumatic lower cervical facet dislocation were retrospectively analyzed from January 2010 to December 2013.Traffic accident was the primary cause of injury,with patients presenting with dislocated segments in C4–5(n = 8),C5–6(n = 10),and C6–7(n = 6).Sixteen patients had unilateral facet dislocation,and 8 had bilateral facet dislocation.Spinal injuries were classified according to the American Spinal Injury Association(ASIA),with 4 cases of grade A,4 cases of grade B,10 cases of grade C,4 cases of grade D,and 2 cases of grade E.On admission,all patients underwent immediate reduction under general anesthesia and combined anterior and posterior fusion.The mean follow-up time was 3.5 years.Results: All operations were completed successfully,with no major complications.Postoperative X-rays showed satisfactory height for the cervical intervertebral space and recovery of the vertebral sequence.Bone fusion was completed within 4 to 6 months after surgery.Surgery also significantly improved neurological function in all patients.Conclusion: Immediate reduction under general anesthesia and combined anterior and posterior fusion can be used to successfully treat lower cervical facet dislocation,obtaining completed decompression,safe spinal re-alignment and excellent immediate postoperative stability.Part 3 Clinical efficacy of anterior partial corpectomy and titanium mesh fusion and internal fixation for the treatment of old fracture dislocation of the lower cervical spineObjective: To analyze the clinical features and to evaluate the efficacy of anterior partial corpectomy and titanium mesh fusion and internal fixation of old fracture dislocation of the lower cervical spine.Methods: We retrospectively analyzed the clinical data of 52 patients with old lower cervical fracture and dislocation treated with anterior partial corpectomy and titanium mesh fusion fixation between January 2008 and December 2013 with a mean follow-up period of 4.1year.There were 35 males and 17 females.Patient radiological data and clinical parameters were recorded and compared before and after operation.Results: The average follow-up was 4.1 years.intervertebral height and physiological curvature were well reconstructed for all cases.No loosening or rupturing of titanium plate or screw occurred.The neurological function of the patients with incomplete spinal cord injury has been significantly improved,and the function of the nerve roots of injury level has also improved in patients with complete spinal cord injury.Bone fusion was completed within 6 months to 1 year after surgery.Conclusion: Completed decompression,sequence and physiological curvature of the cervical vertebra,immediate and long term anterior cervical column support,and nerve function restoration can be achieved by using anterior partial corpectomy and titanium mesh fusion and internal fixation to treat old fracture dislocation of the lower cervical spine.For cases with locked facet joints or posterior structures invading the vertebral canal,the combined anterior and posterior approaches should be performed in order to achieve better results when necessary.