Clinical Effect Of Spinal Canal Decompression Via Isthmic Fenestration In Thoracolumbar Burst Fracture

Backgrounds:Thoracolumbar burst fracture is a common spinal trauma in clinic,which is usually caused by high-energy trauma such as falling injure,traffic accident and so on.Burst fractures mostly involve the failures of anterior and middle columns spinal vertebra,which result in retropulsion of fracture fragments into the spinal canal that may causes spinal cord injury.At present,there are still many controversies about the appropriate treatment strategy of this spinal fracture in academic circles.Posterior approach is a method recognized by the great majority of surgeons.Laminectomy or hemilaminectomy for nerve decompression,but this decompression method also seriously damages the posterior spinal ligament complex(PLC).Laminectomy or hemilaminectomy is the convention decompression procedure of posterior approaches for patients with neurologic deficit,which effectively expands the volume of the spinal canal,but also severely destroy posterior ligamentous complex(PLC)the most important structure to maintain spinal stability.Many studies have shown that laminectomy or hemilaminectomy may increase the risk of kyphosis,implant failure,back pain."Indirect"decompression,a mechanism named "ligamentotaxis" that restores spinal canal volume,can be achieved by applying distraction via pedicle screw instrumentation without laminectomy.Some scholars questioned the decompression efficiency of this technique,because of it was impossible to observe the spinal canal directly.Our study has reported a novel transforaminal approach via isthmic fenestration for decompression of spinal canal in a thoracolumbar burst fracture,which achieves the goals of canal decompression and preserving the PLC at the same time more thoroughly and safely.Objective:To compare the clinical effects of posterior approach with two different decompression methods of laminectomy and isthmic fenestration in treatment of thoracolumbar burst fracture.Methods:A retrospective study of 30 cases of thoracolumbar burst fracture treated in Department of Orthopedics of Qilu Hospital of Shandong University from January 2017 to March 2018.Patients were divided into two groups according to different surgical methods:laminectomy group(group A,n = 16),isthmic fenestration group(group B,n = 14).To evaluated effectiveness by inter-group comparison of operation time,intraoperation blood loss,postoperative drainage,and by intra-group and inter-group comparison of VAS at preoperative,7 days postoperative,1 years postoperative,and by intra-and inter-group comparison of RAVH,Cobb angle,canal encroachment at preoperative,3 days postoperative,and by intra-group comparison of ASIA grading at preoperative and last follow-up.Results:There was no significant difference in age,sex,injury segment distribution,VAS,preoperative RAVH,Cobb angle,spinal canal encroachment in two groups(P>0.05).There was no significant difference in average operation time between group A and group B(P>0.05);the blood loss in group B was significantly lower than that in group A(P<0.001),and the drainage volume in group B was lower than that in group A(P<0.05).The VAS of the two groups were significantly improved compared with those of the preoperative group(P<0.001).The VAS of the two groups were also significantly improved at 1 year follow-up compared with 7 days postoperatively(P<0.001).There was no significant difference in the VAS of the two groups at preoperative and 7 days postoperative(P>0.05).At the 1 year follow-up,the VAS scores of group A were higher than those of group B(P<0.05).The RAVH,Cobb angle and spinal canal encroachment of the two groups were significantly improved at 3 days postoperative compared with preoperative(P<0.001).There was no significant difference in preoperative RAVH,Cobb angle and spinal canal encroachment in group A and group B at preoperative and postoperative(P>0.05).The ASIA grading of the two groups at the last follow-up was significantly improved compared with preoperative(P<0.05).Conclusion:Posterior approach has effective and reliable effect in fracture reduction and deformity correction.The effectiveness of decompression via isthmic fenestration can reach the same level of decompression via laminectomy.This operation has similar effectiveness of canal decompression compared with traditional operation,with less volume of blood loss and drainage,and better pain relife.The neurological function of both groups is improved significantly.In conclusion,spinal canal decompression via isthmic fenestration is a kind of safe,effective surgical technique,which preserve the PLC largely.This technique is uncomplicated,easy to learn and suitable for promotion in primary hospitals.