Objective To investigate the influence of C arm X- ray perspective computer auxiliary surgery navigation system on lumbar vertebral pedicle screw fixation in the elderly.Methods 286 patients(aged≥65 years) treated by lumbar spine post decompress and pedicle screw fixation for lumbar vertebral degeneration were divided into navigation (n=153) or non-navigation (n=133) groups.The amount of blood loss,surgery duration and time of beginning to walk after surgery were measured and compared, the improvement grading was determined by Oswestry disability index (ODI) before surgery and at the last follow-up. Results The surgery duration [(27.6+6.3)ain vs.(33.8±9.9)min],the volume of blood loss[(135.7±21.1)ml vs.(165.4±32.1)ml] and the time of beginning to walk after surgery[(134.6± 12.3)h vs.(169.0±23.9)h] were obviously reduced in navigation group as compared with non-navigation group (P ＜ 0.05). The grading improvement rate by ODI[(76.6±±3.7)％vs.(69.8+6.6)％] was higher in navigation group than in non navigation group (P＜0.05). Conclusions Using C arm X-ray perspective computer auxiliary surgery navigation system to lumbar pedicle screws fixation is helpful in the elderly for improving clinical efficacy.

Objective:To investigate the impact of osteoporosis on clinical outcomes in elderly patients treated with short segment transforaminal lumbar interbody fusion.Methods:From May 2016 to May 2018, elderly patients who had undergone transforaminal lumbar interbody fusion(TLIF)in our hospital were retrospectively analyzed.Based on bone mineral density(BMD), patients were divided into the osteoporosis group(the OP group, n=75, T≤-2.5 in BMD)and the control group(the CO group, n=103, T>-1.0 in BMD). General patient information, clinical data and postoperative follow-up clinical results were compared between the two groups.Results:Eventually 178 cases were enrolled, including 68 with lumbar disc herniation and 110 with lumbar spinal stenosis.Preoperative Visual Analogue Scale(VAS)scores were 7.35±1.30 in the lower back and 7.32±1.30 in the leg for the OP group and 7.35±1.33 and 7.22±1.40, respectively, for the CO group, and there was no significant difference between the two groups( t=0.140 and 0.468, P=0.989 and 0.640). The proportions of cage collapse and internal fixation loosening were 70.7%(53/75)and 37.3%(28/75)in the OP group, which were higher than 22.3%(23/103)and 14.6%(15/103)in the CO group( χ2=41.440 and 12.280, both P=0.000). However, there was no significant difference between the OP group and the CO group in 1-and 2-year postoperative interbody fusion rates(postoperative 1-year rate: 89.3% or 67/75 vs.91.3% or 94/103, χ2=0.187, P=0.666; postoperative 2 year rate: 94.6% or 71/75 vs.95.1% or 98/103), χ2=0.021, P=0.885). There was no significant difference in VAS score and Oswestry disability index(ODI) between the OP group and the CO group at 6 months, 1 year and 2 years after surgery(all P>0.05). Conclusions:Although there are some osteoporosis-related complications such as cage subsidence and screw loosening, short-segment TLIF can still achieve good clinical results in elderly patients with osteoporosis.

Objective To compare the fusion effect between lumbar posterolateral fusion (PLF) and posterior lumbar interbody fusion (PLIF) in elderly patients with lumbar spinal stenosis.Methods Data of 313 patients undergoing PLF or PLIF for treatment lumbar degenerative disease in Department of Orthopedics,Beijing Hospital of China Ministry of Health during January 1996 to December 2011 were retrospectively analyzed.Patients were divided into PLF group (n=116 cases) and PLIF group (n=197 cases).Data of fusion rate,operative time,operative blood-loss and complications were analyzed statistically.Results The fusion rate was 84.5％ in PLF group and 98％ in PLIF group.The average operative time was 247.8 min (120-480 min) and 240.6 min (90-600 min) in PLF and PLIF groups respectively.The blood-loss was 1142.9 ml (200 4500 ml) and 927.0 ml (200-2800 ml) in PLF and PLIF groups respectively.Postoperative complications were found in 38 cases in PLF group and in 36 cases in PLIF group.There were significant differences in fusion rate,operative time,operative blood loss,complications between the two groups (all P＜0.05).Conclusions PLIF has better effects on fusion rate and fusion grade than PLF.

BACKGROUND: Peak bone mass and standard deviation (SD) in different regions are varied, which have great influence on diagnosis of osteoporosis. To establish a complete database can provide accurate evidence for osteoporosis diagnosis. OBJECTIVE: To investigate the influence of bone mineral densities (BMD) and their SD of young people on the detective rate of osteoporosis in general population. DESIGN, TIME AND SETTING: Investigation analysis was performed at Beijing, Shanghai, Guangzhou, Nanjing, Jiaxing and Chengdu between January 1997 and December 1999. PARTICIPANTS: 11418 subjects from related 6 centers of BMD reference database in China were investigated and analyzed using prospective and retrospective methods, including 3 666 males, and 7 752 females aged 20-90 years. Of them, 2385 were from Beijing, 1178 from Guangzhou, 1404 from Shanghai, 2938 from Nanjing, 1425 from Chengdu, and 2088 from Jiaxing. The subjects were selected from community investigation, physical examination volunteers. METHODS: BMD of the lumbar spine (L2-4) and the hip in 11, 418 subjects from the related 6 centers in China was measured with GE-Lunar dual energy X-ray absorptiometry (DXA) and the BMD reference database was established. The accuracy rate of the inner machine was 0.3%-0.7%, and the accuracy of different machines averaged 1.1%. MAIN OUTCOME MEASURES: Lumbar BMD distribution of different age groups from 6 centers; influence of young people's BMD and its SD on detective rate of osteoporosis. RESULTS: Different BMD and SD were found in the individual subject from 6 centers, and the maximum differences were 0.098 g/cm2 and 0.027 g/cm2. With mean BMD and SD of the individuals from 6 centers as references, different T-scores and the detective rates of osteoporosis derived from the T-scores were found in the same group. The detective rate increased by 1.6% when BMD of the young people increased by 0.01 g/cm2 (positive correlation), but the detective rate decreased by 4% when SD increased by 0.01g/cm2 (negative correlation). CONCLUSION: Changes in BMD and SD of the young people can influence the detective rate of osteoporosis. To achieve comparability for the detective rate of osteoporosis in different centers, the specific reference database should be established for the same race, the same area, and the same bone densitometry machine. The T-score should be determined with the normal BMD and SD of the young, people as the reference database.

Objective:To compare the minimally invasive transforaminal lumbar interbody fusion (MTLIF) with open transforaminal lumbar interbody fusion (OTLIF) in treatment of lumbar degenerative disease.Methods:Clinical data of 63 patients with single segment lumbar degenerative disease treated in Department of Orthopedics of Beijing Hospital from November 2015 to September 2016 were retrospectively analyzed, among whom 30 cases received MTLIF and 33 cases received OTLIF. The operative time, intraoperative X-ray exposure times, intraoperative blood lose, postoperative drainage,perioperative fever, adjacent segment degeneration, loosening of internal fixation and cage collapse were observed in two groups 4 years after operation, and the visual analog scale (VAS) score of the lower back and the leg, the Oswestry disability index (ODI) score were compared between two groups.Results:The operation time [(191.6±50.5) min] and radiation exposure times [(15.5±6.4) times] in MTLIF group were significantly more than those in OTLIF group [(105.8±23.1) min, (7.2±1.4)times, t=17.210, t=10.850,all P<0.01]. The intraoperative blood loss [(150.4±70.4) ml], postoperative drainage [(90.4±30.7)ml], VAS score (2.4±0.7) and ODI score (24.5±3.7) 2 weeks after surgery in MTLIF group were significantly lower than those in OTLIF group [(250.7±43.9)ml,(216.3±67.8)ml,(4.5±1.6),(30.6±4.6), t=-12.830, t=-14.070, t=-6.890, t=-5.805,all P<0.01]. There were no significant differences in the incidence of fever [1 case(3.3%) vs. 4 cases(12.1%),χ2=-1.661, P=0.20], VAS score[(1.2±0.7) vs. (1.3±0.6), t=-0.628, P=0.53], ODI score[(14.2±2.7) vs. (14.7±2.5), t=-0.756, P=0.45], fusion rate of Bridwell grade Ⅰ [86.7%(26/30) vs. 84.8%(28/33),χ2=0.042, P=0.84] 1 year after surgery; and the adjacent segment degeneration [0 case(0) vs. 1 case(3.0%),χ2=0.924, P=0.34], internal fixation loosening [1 case(3.3%) vs. 1 case(3.0%),χ2=0.005, P= 0.95] and cage collapse 4 years after surgery [1 case(3.3%) vs. 1case(3.0%),χ2=0.005, P=0.95] between MTLIF group and OTLIF group. Conclusion:Compared with OTLIF, MTLIF has longer operation time and more radiation exposure, but it can achieve full decompression, the same fusion rate, less bleeding, less trauma, faster recovery, fewer complications and satisfactory long-term effect.