Objective To explore the main points and preliminary efficacy of unilateral bi-portal spinal endoscopy(UBE)in the treatment of lumbar disc herniation(LDH).Methods From March 2022 to June 2023,patients admitted to the spinal surgery department for LDH who underwent UBE surgery were divided into traditional UBE technique group and UBE targeting technique group according to different surgical methods.The traditional UBE technology group revealed the entire interlaminar space,while the targeting technique group revealed part of the interlaminar space.ODI disability index,VAS score of lower extremity and low back,and intraoperative and postoperative complications of the two groups were recorded before operation and at 1day,1 month,3months and 6months post-operative-ly.Results A total of 78 patients were included,including 34 patients in the UBE traditional technique group,aged 40.1±12.2 years,16males and 18 females;44 patients in the UBE targeting technique group,aged 39.7±11.3 years,28males and 16 females.There was no significant difference in the basic data between the two groups.The operations were completed as planned.The operation time was 72.03±18.39min vs 46.2±11.85min,and the blood loss was 36.3±10.5ml vs 19.5±5.7ml,respectively.There were no significant differences in ODI disability index,VAS scores of back and lower extremities at 1day before surgery between the two groups.The dosage of postoperative painkillers in the traditional technique group was higher than that in the target technique group,and the VAS score and ODI index of low back pain on the first day after surgery were significantly higher than those in the target group(P＜0.05),but there was no significant difference between the two groups of patients with lower extremity pain,both of which were significantly relieved.There was no significant difference in lumbar and lower extremity pain VAS between the two groups at 1 month,3months and 6months after surgery,but ODI in the traditional technique group was significantly higher than that in the targeting technique group at 1 month and 3 months after surgery.Six months after surgery,the remission rate of modified Macnab criteria in the targeting technique group was 91.5％,and that of the traditional technique group was 89.5％without significant difference(P＞0.05).Cerebrospinal fluid leakage occurred in 1 case in the traditional technique group,and hematoma compression of nerves occurred in 2 cases in the targeting technique group after extubation,which were relieved after conservative treatments.Conclusion UBE targeting technique is more minimally invasive than traditional UBE technique in the treatment of lumbar disc herniation,which is helpful for rapid recovery after surgery.

Objective To explore the main points and preliminary efficacy of unilateral bi-portal spinal endoscopy(UBE)in the treatment of lumbar disc herniation(LDH).Methods From March 2022 to June 2023,patients admitted to the spinal surgery department for LDH who underwent UBE surgery were divided into traditional UBE technique group and UBE targeting technique group according to different surgical methods.The traditional UBE technology group revealed the entire interlaminar space,while the targeting technique group revealed part of the interlaminar space.ODI disability index,VAS score of lower extremity and low back,and intraoperative and postoperative complications of the two groups were recorded before operation and at 1day,1 month,3months and 6months post-operative-ly.Results A total of 78 patients were included,including 34 patients in the UBE traditional technique group,aged 40.1±12.2 years,16males and 18 females;44 patients in the UBE targeting technique group,aged 39.7±11.3 years,28males and 16 females.There was no significant difference in the basic data between the two groups.The operations were completed as planned.The operation time was 72.03±18.39min vs 46.2±11.85min,and the blood loss was 36.3±10.5ml vs 19.5±5.7ml,respectively.There were no significant differences in ODI disability index,VAS scores of back and lower extremities at 1day before surgery between the two groups.The dosage of postoperative painkillers in the traditional technique group was higher than that in the target technique group,and the VAS score and ODI index of low back pain on the first day after surgery were significantly higher than those in the target group(P＜0.05),but there was no significant difference between the two groups of patients with lower extremity pain,both of which were significantly relieved.There was no significant difference in lumbar and lower extremity pain VAS between the two groups at 1 month,3months and 6months after surgery,but ODI in the traditional technique group was significantly higher than that in the targeting technique group at 1 month and 3 months after surgery.Six months after surgery,the remission rate of modified Macnab criteria in the targeting technique group was 91.5％,and that of the traditional technique group was 89.5％without significant difference(P＞0.05).Cerebrospinal fluid leakage occurred in 1 case in the traditional technique group,and hematoma compression of nerves occurred in 2 cases in the targeting technique group after extubation,which were relieved after conservative treatments.Conclusion UBE targeting technique is more minimally invasive than traditional UBE technique in the treatment of lumbar disc herniation,which is helpful for rapid recovery after surgery.

BACKGROUND: Biomechanical mechanisms are complex, and previous studiers focus on the stress conduction in the carpus. However, the stress distribution and characteristics of trabecula in the carpus are rarely reported.OBJECTIVE: To investigate the stress distribution and deformation characteristics of the normal lunate through a two-dimensional sagittal finite element model.METHODS: A normal cadaveric lunate sample was scanned with Micro-CT and the central sagittal image was chosen for further finite element analysis (FEA). The chosen image was processed and imported into the finite element analysis software (Ansys 14.0). A two-dimensional sagittal finite element model of the lunate bone was established. Axial pressure was applied to the model with the wrist held in different positions, and nine regions of interests (ROIs) were identified, for which stress and displacement nephograms were created. These included the first principal stress (S1, the maximum stress in a principal plane), the third principal stress (S3, the minimal stress in a principal plane), shear stress (SXY, the component of stress coplanar with a material cross section), von Mises stress (SEQV, yielding begins when the elastic energy of distortion reaches a critical value)and displacement of each ROI (UY, displacement on the vertical plane of the lunate) which were calculated and compared.RESULTS AND CONCLUSION: (1) The stresses on ROIs located in the proximal and volar cortices of the lunate bone were much higher than those in the distal and dorsal cortices. At the proximal lunate, S1 was less than S3; however at the distal lunate, S1 was greater than S3. The ROIs of the distal and proximal ends of the lunate bone received much higher stress than the ROIs of the middle part. As for axial trabecular displacement,both distal and proximal ROIs were compressed by axial pressure. However, the dorsal and the volar parts of the proximal lunate moved in different directions at different wrist postures. Besides, the stress values and magnitudes of displacement were elevated in wrist flexion and extension compared to neutral position.Furthermore, the stress concentration zones (the proximal volar ROI, the proximal dorsal ROI, the distal volar ROI, and the distal dorsal ROI) had different directions of shear stress and displacement in different wrist postures. (2) These results suggest that when stress is loaded on a normal lunate model, four stress concentration zones, the proximal volar ROI, the proximal dorsal ROI, the distal volar ROI, and the distal dorsal ROI are found. The wrist postures can significantly affect the value and distribution of axial stress on the sagittal lunate.