Objective To evaluate the mid‐term efficacy of microendoscopic discectomy (MED) and microsurgical lumbar discectomy (MSLD) for treating lumbar disc herniation (LDH) .Methods 98 patients with single segment LDH in the Orthopedic department of the Second Hospital of Lanzhou University from March 2009 to April 2010 were divided into 2 groups ,including 44 cases undergoing MED and 54 cases undergoing MSLD .The operative efficacies were assessed by the visual analogue scale (VAS) , Japanese Orthopedic Association (JOA) scores and Oswestry Disability Index (ODI) .Results There were statistically significant differences in the skin incision length ,amount of intraoperative blood loss and time of returning to work between the two groups (P<0 .01) ,while the operation time ,average hospital stay time and incidence of complications showed no statistically significant differences (P>0 .05) .The mean follow‐up duration was 49 .13 months in the MED group and 47 .24 months in the MSLD group respectively .At the last follow‐up the postoperative back and leg pain VAS scores ,JOA scores and ODI in each group were signifi‐cantly improved compared with the preoperative data (P<0 .01) .However ,there were no statistically significant differences in the intergroup comparison .Conclusion MED and MSLD are the effective methods for treating single segment LDH .However ,MED has less trauma and early out‐of‐bed ambulation ,is an ideal minimally invasive surgery .

Objective:To analyze the biomechanical characteristics of bilateral lumbo-iliac fixation by finite element analysis after digital optimization of a safe screw pathway.Methods:Firstly, a healthy adult male volunteer was recruited for this study who underwent CT scanning of the lumbus and pelvis, with a slice thickness of 0.625 mm.The original data were imported into Mimics 16.0 software for 3D lumbar and pelvic reconstruction.At the same time, a geometric screw pathway and a free screw pathway were generated in the pedicles of L4 and L5 and ilium.Secondly, all 3D models were imported into Ansys 12 software to assemble a finite element model.The displacements and von Misses stress distribution were measured in the conditions of forward bending, backward extending, lateral bending to the left and right, and left and right rotations in the models of 2 kinds of pathway after gravity axial load of 500 N was applied.Results:The models of 2 different pathways were similar in comprehensive displacement and stress in the conditions of forward bending, lateral bending and backward extending, and in the maximum stress of the screw in the conditions of forward bending and lateral bending.However, the comprehensive displacement and stress in the condition of rotation and the stress of the screw in the conditions of backward extending and rotating in the model of geometric screw pathway were obviously smaller than those in the model of free screw pathway.The maximum pelvic stress was on the screw surface between 190 and 260 MPa, concentrated on the bending area of the 2 screws connecting the sacrum and vertebral body.The lumbar-iliac fixation model showed high com-pressive stiffness.The maximum von Misses stress appeared in the L4-L5 pedicle screw on the longitudinal rod.Under rotational loading, the upper longitudinal rod connecting the L4-L5 pedicle screw and the iliac bone screw bore the maximum stress.Conclusions:Our finite element analysis shows that double verte-bral bodies and long screw fixation are effective ways of iliolumbar fixation.The geometric screw path optimized by digital analysis exhibits better fatigue resistance, rotation resistance and overall stability.Internal lum-bo-iliac fixation can effectively share the stress of vertebral bodies.

Objective:To investigate the influencing factors for textbook outcome (TO) after hepatectomy for hepatolithiasis.Methods:The retrospective case-control study was conducted. The clinicopathological data of 216 patients with hepatolithiasis who were admitted to The First Affi-liated Hospital of Anhui Medical University from January 2015 to March 2023 were collected. There were 69 males and 147 females, aged 61(range, 22-85)years. Observation indicators: (1) treatment situations; (2) TO after hepatectomy; (3) Influencing factors for TO after hepatectomy. Measurement data with normal distribution were represented as Mean± SD. Measurement data with skewed distribution were represented as M(range). Count data were expressed as absolute numbers. Logistic regression models were used for univariate and multifactorial analyses. Results:(1) Treatment situations. All the 216 patients underwent hepatectomy, including 45 cases of laparoscopic hepatectomies and 171 cases of open hepatectomies, 161 cases of anatomical hepatectomies and 55 cases of non-anatomical hepatectomies. All the 216 patients underwent intraoperative choledochoscopy exploration and lithotripsy. There were 170 patients with normal Oddi sphincter function and 46 patients with Oddi sphincter dysfunction. All the 216 patients underwent biliary drainage, including 198 cases of external T-tube drainage and 18 cases of internal bile-intestinal drainage. The operation time was (226±75)minutes and volume of intraoperative blood loss was (106±82)mL. There were 29 patients with perioperative blood transfusion and 14 patients with intraoperative severe adverse events. There were 189 patients achieved immediate stone clearance. Of 183 patients with intraoperative bile cultures, 76 cases were positive for bacteria culture. (2) TO after hepatectomy. Of 216 patients, 93 cases had postoperative complications, all of which were successfully discharged after active treatment. One patient had surgery-related death within 90 days after surgery, and the cause of death was liver failure. Five patients were readmitted within 90 days after surgery, and 18 patients had postoperative stone residual. Of 216 patients, 164 cases achieved TO postoperatively and 52 cases did not achieve TO postoperatively. (3) Influencing factors for TO after hepatectomy. Results of multivariate analysis showed that cholangitis, stone distribution, surgical approaches, anatomical hepatectomy, immediate stone removal and postoperative review of choledochoscopy were independent influencing factors for TO after hepatectomy in patients with hepatolithiasis ( P<0.05). Conclusion:Cholangitis, stone distribution, surgical approaches, anatomical hepatectomy, imme-diate stone removal and postoperative review of choledochoscopy are independent influencing factors for TO after hepatectomy in patients with hepatolithiasis.