Objectives:The purpose of this study was to investigate the clinical efficacy of percutaneous endoscopic transforaminal lumbar interbody fusion(PE-TLIF)in patients with single-segment lumbar spinal stenosis and explore the changes of paraspinal muscles and adjacent segmental facet joints of operative segement after PE-TLIF.Methods:28 patients with L4/5 lumbar spinal stenosis treated with PE-TLIF in Beijing Chaoyang Hospital from March 2017 to March 2019 were analyzed retrospectively.The patients consisted of 12 males and 16 females with an average age of 58.0±8.7 years(41-79 years)and were followed up for 40.7±3.6 months(36-58 months).The visual analogue scale(VAS)of low back pain(VAS-LBP)and VAS of leg pain(VAS-LP)were collected at pre-operation,postoperative 1-week follow-up,3-month follow-up,12-month follow-up and the final follow-up;Oswestry disability index(ODI)was evaluated at pre-operation,post-operative 3-month follow-up,12-month follow-up and the final follow-up.CT examination was performed at pre-operation,postoperative 12-month follow-up,24-month follow-up and the final follow-up,the cross-sec-tional area(CSA)and fat infiltration(FI)score of multifidus(MF)were measured,and the degeneration degree of adjacent segmental facet joints was evaluated according to the score of facet joint degeneration.The differ-ences of MF CSA and FI score,as well as adjacent segmental facet joint degeneration were compared be-tween preoperation and postoperation.Results:The VAS-LBP score was 3(2,3)at 1-week follow-up,1(1,2)at 3-month follow-up,1(0,2)at 12-month follow-up,and 1(0,1)at the final follow-up,which was signif-icantly improved compared with the preoperative score of 7(7,8)(P＜0.05);the VAS-LP score was 2(1,3)at 1-week follow-up,1(1,2)at 3-month follow-up,1(0,1)at 12-month follow-up,and 0(0,1)at the final fol-low-up,which were significantly improved compared with the preoperative score of 6(5,7)(P＜0.05);The ODI at 3-month follow-up was 23％(19％,31％),at 12-month follow-up was 12％(8.5％,17.5％),and at the final follow-up was 7％(4％,15.6％),all significantly improved compared with the ODI before operation of 61％(55％,67％)(P＜0.05).The postoperative MF CSAs of 547.12±53.31mm2(12-month follow-up),558.35±52.37mm2(24-month follow-up),and 531.21±56.12mm2(final follow-up)were not significantly changed from the preoper-ative MF CSA of 557.06±46.72mm2(P＞0.05).There was no significant difference in FI score between pre-op-eration of 2(2,3)and 12-month follow-up of 3(2,3),24-month follow-up of 3(2,3)and the final follow-up of 3(3,3)(P＞0.05).The postoperative facet joint degeneration scores of upper segment facet joint(USFJ)of 5(4,6)at 12-month follow-up,5(4,5)at 24-month follow-up,and 5(4,6)at final follow-up were not signifi-cantly changed from the preoperative 5(4,6)(P＞0.05).And there was no significant difference either in facet joint degeneration score of lower segment facet joint(LSFJ)between pre-operation of 5(4,6)and 12-month follow-up of 5(4,5),24-month follow-up of 5(4,6)and the final follow-up of 5(4,7)(P＞0.05).Conclusions:PE-TLIF can achieve satisfactory clinical outcomes in the treatment of single-segment lumbar spinal stenosis,which has no significant effect on multifidus in the surgical segment and adjacent segmental facet joints in the mid-to long-term.

Objectives:To compare the clinical outcomes of posterior lumbar interbody fusion(PLIF)and per-cutaneous endoscopic transforaminal lumbar interbody fusion(PE-TLIF)in treating single-segment lumbar spinal stenosis and their effects on the paraspinal muscles.Methods:This prospective study included 52 patients with L4/5 lumbar spinal stenosis treated in our hospital between January 2019 and January 2022.Among the patients,22 were in the PLIF group(10 females,12 males,aged 60.2±10.3 years old)and 30 were in the PE-TLIF group(14 females,16 males,aged 60.4±12.3 years old).The two groups were compared of the peri-operative indicators including operative time,intraoperative blood loss,postoperative drainage volume,and postoperative bed rest time;And paraspinal muscles related indicators such as creatine kinase(CK)before op-eration and at postoperative 1d and 1 week,and multifidus muscle(MF)cross-sectional area(CSA),fatty infil-tration(FI)score,and muscle CT density before operation and at postoperative 6 and 12 months;Preoperative,postoperative 1d,1 week,6 months and 12 months'visual analogue scale on low back pain(VAS-LBP),visual analogue scale on leg pain(VAS-LP),and 0swestry disability index(0DI).The complications of the two groups were analyzed and compared,and at 12 months after operation,the fusion rate was evaluated and compared according to the Bridwell criteria.Results:PE-TLIF group was different from PLIF group significantly in op-erative time(211.2±38.5min vs 98.9±31.6min,P=0.000),postoperative bed rest time(25.9±8.3h vs 52.4±14.8h,P=0.001),intraoperative blood loss(112.8±79.6mL vs 232.5±122.5mL,P=0.002),and postoperative drainage vol-ume(46.5±28.2mL vs 283.6±142.1mL,P=0.000).The MF CSA before operation,at 6 and 12 months after op-eration was not significantly different between PE-TLIF group and PLIF group(P＞0.05),and there was no sta-tistical difference between pre-operation MF CSA and MF CSA 6 months and 12 months after surgery within either group(P＞0.05).The PE-TLIF group was not significantly different from the PLIF group in MF FI score before operation and at 6 months after operation(P＞0.05),while at 12 months after operation,the PE-TLIF group was lower than the PLIF group[3.0(2.8,3.0)vs 3.0(3.0,4.0),P=0.031].There was no statistical differ-ence in MF FI score between pre-operation,6 months after surgery and 12 months after surgery within the PE-TLIF group(P＞0.05).And,there was no statistical difference in MF FI score between pre-operation and 6 months after surgery in the PLIF group(P＞0.05),while statistically significant difference was found between pre-operation and 12 months after surgery in the PLIF group[3.0(2.0,3.3)vs 3.0(3.0,4.0),P=0.016].The dif-ference in preoperative MF CT density and MF CT density 6 months after operation between the two groups was not statistically significant(P＞0.05).At the 12-month follow-up,MF CT density in the PLIF group was significantly lower than that in the PE-TLIF group[30.5(28.5,32.1)HU vs 34.2(31.8,36.9)HU,P=0.000].There was no significant difference in MF density between pre-operation,and 6 months after surgery or 12 months after surgery within the PE-TLIF group(P＞0.05).And there was no statistically significant difference in MF density between pre-operation and 6 months after surgery in the PLIF group(P=0.516),but there was a statis-tical difference between pre-operation and 12 months after surgery within the PLIF group[34.6(30.5,36.4)HU vs 30.5(28.5,32.5)HU,P=0.017).The PE-TLIF group and PLIF group was not significantly different in pre-operative CK(P=0.712),while the PE-TLIF group was lower on Id and 7d after operation(P＜0.05).VAS-LBP,VAS-LP,and 0DI at all follow-up time points after surgery of both groups were better compared to those before surgery(P＜0.05).The VAS-LBP of the PE-TLIF group was better than that of the PLIF group at 1d and 1 week after surgery(P＜0.05).There was no statistical difference in VAS-LBP between the PLIF and PE-TLIF at 6 months or 12 months after surgery.There was no statistical difference in VAS-LP or ODI between the PLIF and PE-TLIF at any follow-up time point(P＞0.05).There was no significant difference in the inci-dence of postoperative complications between the two groups(P=0.379).And there was no significant difference in the fusion rate between the two groups(P=0.877).Conclusions:PE-TLIF can achieve similar clinical out comes as traditional PLIF in the treatment of single-segment lumbar spinal stenosis,which reduces effects on paraspinal muscles and alleviate operative trauma.

Objective To explore the efficacy of closed reduction and inter na l fixation of cannulated screws by minimally invasive procedure in management of tibial plateau fractures. Methods From October 1999 to January 2002, 42 patient s with tibial plateau fractures, which were 29 males and 13 females with an aver age age of 41 years ranging from 26 to 67 years, were treated surgically in our hospital. According to Schatzker system, the fractures were diagnosed as type Ⅰ in 9, type Ⅱ in 5, type Ⅲ in 13, type Ⅳ in 3, type Ⅴ in 6 and type Ⅵ in 6. There was open fracture in 5, and closed fracture in 37. The fracture fragments of tibial plateau were reduced with closed manipulation or reduced assisted by minimally invasive procedure. The later by minimally invasive procedure included two kinds of reductions, one of which was reduction assisted by Kirschner pin t hat was introduced percutaneously into the larger fragment; the other was reduct ion assisted by a bone tamper that was introduced through a small incision into the cortical window beneath the depressed articular surface. Fixation was achiev ed using percutaneous 6.5 mm cannulated screws or combination of the cannulated screws and Bastiani external frame in unstable fractures. Results Of 42 patients , 37 were followed up from 6 to 30 months (average, 15 months). All 37 fractures were united within 12 weeks postoperatively. The mechanical axis of affected li mb and the stability of affected knee joint were restored in the patients. Accor ding to Sanders score for functional results of knee joint, 13 patients were rat ed as excellent, 20 good, and 4 fair. Anatomical reduction was identified while the stepping of articular surface after reduction was less than 2 mm. In 21 pati ents with anatomical reduction, the functional results were excellent in 8, good in 11, and fair in 2. However, in 16 patients without anatomical reduction, the functional results were excellent in 5, good in 9, and fair in 2. There was sig nificant difference between the two groups on functional results. There were no postoperative complications such as infections and neurovascular bundle. Conclus ion Closed reduction and fixation through minimally invasive procedure has provi ded satisfied results in tibial plateau fractures such as less complications, ex cellent mechanical axis restoration, and ideal functional recovery.