Effect of pure muscle retraction on multifidus injury and atrophy after posterior lumbar spine surgery with 24 weeks observation in a rabbit model.

PURPOSE: To evaluate the effect of pure muscle retraction on multifidus injury and atrophy. MATERIALS AND METHODS: Sixty-three adult New Zealand white rabbits were divided evenly into three groups: 1-h retraction (group R1), 2-h retraction (R2), and sham surgery (C). The multifidus muscle was evaluated using magnetic resonance imaging (MRI) and histology after 3 and 48 h, and 1, 3, 6, 12, and 24 weeks after surgery. RESULTS: Multifidus muscle injury and atrophy were not observed in group C, but were obvious in groups R1 and R2. Edema, necrosis, and inflammation mainly occurred in the first week postoperatively, and were more severe in R2 than in R1 (P < 0.01). Muscle fiber regeneration began at week 1, fibrotic changes mainly occurred at weeks 3 and 6, and fat degeneration became obvious at weeks 12 and 24 postoperatively. The fibrosis and fat degeneration scores of R2 were higher than those of R1 (P < 0.01). Decreased acetylcholine activity and granular degeneration of the neuromuscular junction were observed in both retraction groups, but was more severe in R2 than in R1 (P < 0.01). CONCLUSION: Muscle retraction was an important factor not only for multifidus injury, but also for long-term multifidus atrophy after posterior lumbar surgery; a longer retraction time caused more severe multifidus injury and atrophy. Muscle fibers can be regenerated postoperatively, and denervation might be the reason for muscle atrophy.

Quantitative MRI analysis of the surface area, signal intensity and MRI index of the central bright area for the evaluation of early adjacent disc degeneration after lumbar fusion.

PURPOSE: The aim of this study was to evaluate early ASD at short-term follow-up in fused and unoperated patients with degenerative disc disease, using quantitative magnetic resonance imaging (MRI) analysis of the area, signal intensity and their product, i.e., MRI index of the central bright area of the disc as well as measures of intervertebral disc height and Pfirrmann grading scale. The further purpose was to determine whether fusion accelerates ASD compared with non-surgical treatment in short-term follow-up. METHODS: One hundred and eight chronic low back patients diagnosed as L4/L5 degeneration undertook either one-level instrumented posterior lumbar interbody fusion or conservative treatment. They were followed up for about 1 year. Finally 46 fused and 45 conservatively treated patients with MRI follow-up were included. Pre- and post-treatment MRIs were compared to determine the progression of disc degeneration at the two cranial adjacent segments. RESULTS: The area, signal intensity and MRI index of the central bright area of the adjacent discs decreased in the operated and unoperated groups from pre-treatment to follow-up, except for an insignificant decrease of signal intensity at the second adjacent segment in the unoperated group. The changes in these parameters were statistically greater at the first than the second adjacent segment in the fused group, but not in the unoperated group. And the changes in the fused group were more pronounced than those at both neighbouring levels in the unoperated group. However, the Pfirrmann grading scale and intervertebral disc height did not detect any changes at adjacent discs in either group. CONCLUSIONS: Decrease in the parameters of quantitative MRI analysis indicated early degeneration at discs adjacent to lumbar spinal fusion. Fusion had an independent effect on the natural history of ASD during short-term follow-up. Continued longitudinal follow-up is required to determine whether these MRI changes lead to pathologic changes.

Different responses of cervical intervertebral disc caused by low and high virulence bacterial infection: a comparative study in rats.

The aims of this study were to investigate the outcomes of low- and high-virulence bacterial cervical intervertebral discs (IVDs) infection and its association with cervical IVDs degeneration in rats. A total of 75 clean grade male rats were used to establish the corresponding animal models of low and high virulent bacterial cervical disc infection via an anterior cervical approach, with injection of Propionibacterium acnes (P. acnes) and Staphylococcus epidermidis (S. epidermidis) with a 29 G needle to cervical IVDs. Specimens were collected for evaluation of Blood routine (Blood-RT), histological staining, and gene expression assays after a magnetic resonance imaging (MRI) scan. There were no statistical differences in all groups in white blood cells (WBC) at 2 and 6 weeks postoperatively (P = 0.136). The highest percentage of neutrophils was found in the S. epidermidis group at 2 weeks postoperatively (P = 0.043). MRI and histology showed that at 6 weeks postoperatively, the puncture group and P. acnes group had similar disc degeneration. In the S. epidermidis group, the disc and subchondral bone structure had been destroyed and bony fusion had occurred after the discitis. The upregulation of pro-inflammatory factor expression had the strongest effect of S. epidermidis on the early stage, while the upregulation in the puncture and P. acnes groups was more persistent. P. acnes infection of the cervical IVDs can lead to degenerative changes, whereas S. epidermidis infection leads to the manifestation of septic discitis. The correlation between P. acnes infection and cervical IVDs degeneration found in clinical studies was confirmed.

Comparison of Oblique Lateral Interbody Fusion (OLIF) and Minimally Invasive Transforaminal Lumbar Interbody Fusion (MI-TLIF) for Treatment of Lumbar Degeneration Disease: A Prospective Cohort Study.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: To assess the differences in the clinical and radiological outcomes between oblique lateral interbody fusion (OLIF) and minimally invasive transforaminal lumbar interbody fusion (MI-TLIF). SUMMARY OF BACKGROUND DATA: Nowadays, there is still a controversy regarding whether OLIF is superior to MI-TLIF in the management of degenerative lumbar disease. METHODS: Between August 3, 2019 and February 3, 2020, 137 patients were assigned to OLIF or MI-TLIF at their request and the surgeon's discretion: 71 in the OLIF group and 66 in the MI-TLIF group. The perioperative data, patient-reported outcomes, radiographic outcomes, and complications were compared between the two groups. RESULTS: The OLIF group showed shorter operation time (110.5 vs.183.8 minutes, P < 0.001), lesser estimated blood loss (123.1 vs. 232.0 mL, P < 0.001), shorter length of hospital stay (5.5 vs. 6.7 days, P < 0.001), and lower serum creatine kinase (CK) (1 day postoperatively) (376.0 vs. 541.8 IU/L, P < 0.01) than that of MI-TLIF group. Both groups showed no significant differences in the visual analog scale (VAS) scores of lower back and leg pain and the Oswestry Disability Index (ODI) scores preoperatively and at 1, 3, and 12 months postoperatively, respectively (P > 0.05). Compared with the MI-TLIF group, the OLIF group showed better restoration of disc height (DH) (4.7/4.6/4.7 vs. 3.7/3.7/3.7 mm, P < 0.01) and lumbar lordosis angle (LLA) (10.5°/10.8°/11.1° vs. 5.8°/5.7°/5.3°, P < 0.001), but not the value of segmental lordosis angle (SLA) (P > 0.05) at 1 day, 1 month, and 1 year postoperatively, respectively. The complication rate of OLIF was higher than that of MI-TLIF (29.4% vs. 9.7%, P < 0.01). CONCLUSION: Compared with MI-TLIF, OLIF showed similar results in terms of patient-reported outcomes, restoration of SLA and fusion rate, and superior results with respect to restoration of DH and LLA, operation time, estimated blood loss, length of hospital stay, and serum CK levels (1 day postoperatively). Even though the complication rate of OLIF is higher than that of MI-TLIF, it does not bring persistent and substantial damage to the patients.Level of Evidence: 3.

[Establishment of finite element model of anterior cervical transpedicular system for reconstruction of cervical stability after subtotal resection of two segments of lower cervical spine].

OBJECTIVE: To establish the fixation model of anterior cervical transpedicular system (ACTPS) after subtotal resection of two segments of lower cervical spine(C3-C7) in order to provide a finite element modeling method for anterior cervical reconstruction. METHODS: The CT data of the cervical segment (C1-T1) of a 30-year-old adult healthy male volunteer was collected. Used Mimics 10.0, Rapidform XOR3, HyperMesh 10.0, CATIA5V19 and ANSYS 14.0 to establish the three-dimensional nonlinear complete model of lower cervical spine(C3-C7) as the intact group. The number of units and nodes of the complete model were recorded. After the effectiveness of the complete model was verified, the C5 and C6 vertebral subtotal resection was performed, and the ACTPS model was established as the ACTPS group. The axial force of 75 N and moment couple of 1N·m was loaded on the upper surface of C3 in intact group and ACTPS group, the range of motion(ROM)and stress distribution in states of flexion extension, lateral flexion, rotation was compared between two groups. RESULTS: There were 85 832 elements and 23 612 nodes in the complete model of lower cervical spine(C3-C7) which was established in this experiment. The stress distribution of ACTPS internal fixation model was relatively uniform. Comparing with the intact group, the overall range of motion in ACTPS group was decreased in flexion extension, lateral flexion and rotation directions, and the corresponding compensation of adjacent C3,4 segment was increased slightly. CONCLUSION: The stress distribution of ACTPS fixation system is uniform, there is no stress concentration area at the joint of screw and titanium plate, and the fracture risk of internal fixation is low. It is suitable for stability reconstruction after anterior decompression of two or more cervical segments.

Urolithin A Promotes Angiogenesis and Tissue Regeneration in a Full-Thickness Cutaneous Wound Model.

The treatment of chronic wound is an important topic of current clinical issue. Neovascularization plays a crucial role in skin wound healing by delivering fresh nutrients and oxygen to the wound area. The aim of this study was to investigate the mechanisms of urolithin A (UA) in angiogenesis during wound healing. The results of in vitro experiments showed that treatment with UA (5-20 µM) promoted the proliferation, migration, and angiogenic capacity of HUVECs. Furthermore, we investigated the effect of UA in vivo using a full-thickness skin wound model. Subsequently, we found that UA promoted the regeneration of new blood vessels, which is consistent with the results of accelerated angiogenesis in vitro experiments. After UA treatment, the blood vessels in the wound are rapidly formed, and the deposition and remodeling process of the collagen matrix is also accelerated, which ultimately promotes the effective wound healing. Mechanistic studies have shown that UA promotes angiogenesis by inhibiting the PI3K/AKT pathway. Our study provides evidence that UA can promote angiogenesis and skin regeneration in chronic wounds, especially ischemic wounds.

Anteroinferior Psoas Technique for Oblique Lateral Lumbar Interbody Fusion: Technical Note and Case Series.

OBJECTIVE: The aim of the present paper was to evaluate cases of lumbar degenerative diseases treated with oblique lateral interbody fusion (OLIF) using a modified lateral approach (i.e. anteroinferior psoas exposure under direct vision) and to analyze the effect and safety of this approach. METHODS: From June 2016 to April 2019, a total of 226 patients with an average age of 65.5 ± 16.2 years (98 men and 128 women) with degenerative lumbar diseases who underwent the AIP approach of OLIF were followed up and analyzed retrospectively. Data concerning operative and clinical parameters were collected, including operative time, intraoperative estimated blood loss, duration of postoperative hospital stay, and time to ambulation after surgery. For the assessment of clinical outcomes, the visual analogue scale (VAS) score (for back pain) and the Oswestry disability index (ODI) were calculated. Complications were also recorded as surgical exposure approach-related complications. More than 6 months after surgery, 132 patients consented to having MRI examinations to evaluate the psoas muscle atrophy when they were followed up. RESULTS: The mean operative time was 82.5 ± 31.6 min. The mean operative time for each segment of OLIF was 43.3 ± 15.5 min. The mean blood loss was 48.0 ± 11.6 mL. The mean blood loss for each segment of OLIF was 25.3 ± 10.1 mL. No patients needed blood transfusion intraoperatively or postoperatively. The mean hospital stay was 4.1 ± 2.1 days. All patients were followed up for 12-31 months (mean 18.2 months). Clinical assessment showed that the VAS and ODI scores at 6 months after surgery were markedly lower than the preoperative scores (P < 0.001) but did not differ from the scores at the final follow-up (P > 0.05). There was no significant difference in percentage changes of the cross-sectional area of the lean psoas muscle and the T2 signal intensity ratio of gross psoas to quadratus lumborum muscles between the left side (operative side) and the right side (nonoperative side) (P > 0.05). A total of 11 surgical exposure approach-related complications were reported, with an incidence of 4.9%: transient thigh pain/numbness, psoas weakness (2.2%), sympathetic chain injury (1.3%), cage subsidence (0.9%), and segmental artery injury (0.4%). There was no permanent motor neurological deficit, and no injury of vascular, ureter or peritoneal membranes. CONCLUSION: The anteroinferior psoas approach for OLIF is safe and can preserve the psoas and lumbar plexus.

[Short-segment pedicle screw fixation combined with vertebroplasty for the treatment of Kümmell disease with kyphosis].

OBJECTIVE: To explore the clinical effects of posterior short-segment pedicle screw internal fixation combined with vertebroplasty for the treatment of Kümmell disease with kyphosis. METHODS: Twenty-four patients with Kümmell disease complicated with kyphosis treated by posterior short-segment pedicle screw internal fixation combined with vertebroplasty from January 2016 to December 2018 were retrospectively analyzed, including 6 males and 18 females, aged 63 to 85 (73.1±6.5) years old. The clinical effect was evaluate by visual analogue scale (VAS), Oswestry Disability Index (ODI), the anterior height of injured vertebral body, and the sagittal Cobb angle of the affected segment beforeoperation, at 3 days and final follow up after operation. And the surgical complications were observed. RESULTS: All 24 patients were followed up from 12 to 24 months with an average of (15.5±3.2) months. The VAS score was decreased from 5.21±1.06 preoperatively to 2.38±0.58 at 3 days postoperatively and 1.71±0.75 at final follow-up;ODI was decreased from (50.4±13.5)% preoperatively to (20.9±8.0)% at 3 days postoperatively and (16.7±9.6)% at final follow-up;the anterior height of injured vertebral body was restored from (8.0±4.2) mm before surgery to (18.1±5.0) mm at 3 days after surgery and (16.8±5.1) mm at final follow up;the sagittal Cobb angle of affected segment was decreased from (19.5±6.3)° preoperatively to (7.6±2.1)° at 3 days after surgery and(8.4±1.7)° at final follow-up. VAS, ODI, anterior height of injured vertebral body, and sagittal Cobb angle of affected segment were significantly improved at 3 days after operation and at final follow-up (P<0.05). Two patients had complications, including asymptomaticcement leakage in 1 patient and superficial wound infection in 1 patient. CONCLUSION: Posterior short-segment pedicle screw internal fixation combined with vertebroplasty for the treatment of Kümmell disease with kyphosis has relatively small surgical trauma, excellent clinical results, good vertebral height recovery, satisfactory correction of kyphotic angle, and fewer complications, etc. It is a safe and effective surgical method to treat Kümmell disease with kyphosis.

Anteroinferior Psoas Technique for Oblique Lateral Lumbar Interbody Fusion.

Oblique lateral lumbar interbody fusion (OLIF) has been extensively used, with satisfactory outcomes for the treatment of degenerative lumbar disease. This article aims to demonstrate a modified lateral approach, also known as the anteroinferior psoas (AIP) technique for OLIF, which is expected to enhance security by operating under direct vision. The core procedures of our technique are as follows. First, a minimal skin incision is recommended 2 cm backward compared with the normal incision of OLIF, facilitating the oblique placement of the working channel and the orthogonal maneuver for the cage placement. Second, two special custom-made retractors, as an alternative to the index finger, are used to pull the psoas muscle to the dorsal side and pull the abdominal organs together with extraperitoneal fate to the ventral side under direct visualization, making the exposure of the working channel convenient and safe and avoiding radiation exposure. Third, the anterior border of the psoas is bluntly dissected and retracted backwards, obviously enlarging the retroperitoneal anatomic corridor and then expanding clinical indications of OLIF. The benefits of this technique include that it has a short learning curve, satisfactory clinical outcomes, and low risk of perioperative complications.

Endplate injury as a risk factor for cage retropulsion following transforaminal lumbar interbody fusion: An analysis of 1052 cases.

ABSTRACT: Although transforaminal lumbar interbody fusion (TLIF) is a widely accepted procedure, major complications such as cage retropulsion (CR) can cause poor clinical outcomes. Endplate injury (EI) was recently identified as a risk factor for CR, present in most levels developing CR. However, most EIs occurred in non-CR levels, and the features of EIs in CR levels remain unknown.The aim of this study was to identify risk factors for CR following TLIF; in particular, to investigate the relationship between EIs and CR, and to explore the features of EIs in CR.Between October 2010 and December 2016, 1052 patients with various degenerative lumbar spinal diseases underwent bilateral instrumented TLIF. Their medical records, radiological factors, and surgical factors were reviewed and factors affecting the incidence of CR were analyzed.Twenty-one patients developed CR. Nine had back pain or leg pain, of which six required revision surgery. A pear-shaped disc, posterior cage positioning and EI were significantly correlated with CR (P < .001, P = .001, and P < .001, respectively). Computed tomography (CT) scans revealed the characteristics of EIs in levels with and without CR. The majority of CR levels with EIs exhibited apparent compression damage in the posterior part of cranial endplate on the decompressed side (17/18), accompanied by caudal EIs isolated in the central portion. However, in the control group, the cranial EIs involving the posterior part was only found in four of the total 148 levels (P < .001). Most of the injuries were confined to the central portion of the cranial or caudal endplate or both endplates (35 in 148 levels, 23.6%). Additionally, beyond cage breaching into the cortical endplate on lateral radiographs, a characteristic appearance of coronal cage misalignment was found on AP radiographs in CR levels with EIs.A pear-shaped disc, posterior cage positioning and EI were identified as risk factors for CR. EI involving the posterior epiphyseal rim had influence on the development of CR. Targeted protection of the posterior margin of adjacent endplates, careful evaluation of intraoperative radiographs, and timely remedial measures may help to reduce the risks of CR.

[Comparative study between 3D guide plate assisted and free-hand insertion of anterior cervical transpedicular screw].

OBJECTIVE: To compare accuracy of anterior cervical pedicle screws between assist of rapid prototyping 3D guide plate and free-hand insertion, and evaluate the safety of two methods. METHODS: Eight adult cervical cadaver specimens after formaldehyde immersion, including 4 males and 4 females, aged 32 to 65(40.3±5.6) years old. After X-ray examination to exclude bone damage and deformity, 4 of them (3D guide plate group) randomly selected were for CT scan to obtain DICOM format data, and the data was imported into Mimics software for model, designed the ideal entry point and nail path for anterior cervicaltranspedicular screw (ATPS). After obtaining the personalized guide plate of the nail channel, it was exported as STL data, and the individual guide plate was printed by rapid prototyping and 3D printing technology. In turn, with the assistance of 3D guide plates, one-to-one personalized ATPS screws were placed on the four lower cervical cadaver specimens. Another 4 (free-hand group) lower cervical cadaver specimens were implanted with ATPS screws using free-hand technique. All specimens were performed CT thin-layer scanning and three-dimensional reconstruction after operation. The Tomasino method was used to evaluate the safety of the screws on the CT cross-sectional and sagittal images, to determine whether there was a cortical puncture of the lower and inner edges of the pedicle. According to the CT rating results, gradeⅠandⅡwere safe, and grade Ⅲ- Ⅴ were dangerous.And the accuracy of screws was recorded and analyzed between two groups. RESULTS: Two screws were inserted in each segment from C3 to C7 in 8 adult cadavers. A total of 80 screws were inserted, 40 in the 3D guide plate group, and 40 in the free-hand group. The Tomasino screw rating method was used to evaluate the safety of screw, 21 screws were gradeⅠ, 14 screws were gradeⅡ, 3 screws were grade Ⅲ, 1 screw was grade Ⅳ, 2 screws were grade Ⅴ in 3D guide plate group, while 14 screws were gradeⅠ, 8 screws were gradeⅡ, 8 screws were grade Ⅲ, 6 screws were grade Ⅳ, 2 screws were grade Ⅴ in free-hand group. The safety rate of 3D guide plate group was 87.5%, and 55.0% of the free hand group (χ2=8.7, P=0.003). CONCLUSION: The 3D printing rapid prototyping guide plate assisted insertion of the anterior cervical pedicle screw can significantly improve the accuracy and safety, and provide a theoretical basis for further clinical application.

EIF4A3-induced circular RNA PRKAR1B promotes osteosarcoma progression by miR-361-3p-mediated induction of FZD4 expression.

Emerging evidence indicates that circRNAs are broadly expressed in osteosarcoma (OS) cells and play a crucial role in OS progression. Recently, cancer-specific circRNA circPRKAR1B has been identified by high-throughput sequencing and is recorded in publicly available databases. Nevertheless, the detailed functions and underlying mechanisms of circPRKAR1B in OS remains poorly understood. By functional experiments, we found that circPRKAR1B enhanced OS cell proliferation, migration, and promotes OS epithelial-mesenchymal transition (EMT). Mechanistic investigations suggested that circPRKAR1B promotes OS progression through sponging miR-361-3p to modulate the expression of FZD4. Subsequently, we identified that EIF4A3 promoted cirPRKAR1B formation through binding to the downstream target of circPRKAR1B on PRKAR1B mRNA. Further rescue study revealed that overexpression of the Wnt signalling could impair the onco-suppressor activities of the silencing of circPRKAR1B. Interestingly, further experiments indicated that circPRKAR1B is involved in the sensitivity of chemoresistance in OS. On the whole, our results demonstrated that circPRKAR1B exerted oncogenic roles in OS and suggested the circPRKAR1B/miR-361-3p/FZD4 axis plays an important role in OS progression and might be a potential therapeutic target.

[In vivo study of innervation of degenerative intervertebral discs in rabbit anular-injury model].

OBJECTIVE: To observe degenerative intervertebral disc and to examine innervation of degenerative discs in the rabbit anular-injury model. METHODS: Two different magnitudes of anular injury at 5 mm depth were performed by 11 blade or 16 gauge needle at the L3-L4 or L5-L6 discs in New Zealand white rabbits (n=48, 2.5-3.0 kg). Disc degeneration was evaluated by radiographic, MRI and histological examination at different time points after surgery. To identify nerve ingrowth into disc, two general markers PGP 9.5 and GAP 43, for nerve fibers were examined by immunohistochemistry. RESULT: Significant decreases in disc height and signal intensity in magnetic resonance imaging were observed in 11 blade group and 16 G puncture group (P<0.01). 16 G puncture group induced slower and more progressive disc degeneration companed with the stab group and control group. At the 12-week time point, nucleus pulposus tissues were extruded and scar tissues formed outside the disc. In stab discs, nerve ingrowth was scattered on the surface of injury site and in the deeper part of the scar tissues, more than 1 mm from the surface. However, in punctured discs, PGP 9.5 and GAP 43-immunoreative fibers were only observed in the outmost part of the scar tissues and superficial area. More nerve fibers were observed in stab group. CONCLUSION: Innervation may act as a source of discogenic pain which is associated with intervertebral disc degeneration caused by disc anular injury.

One-stage Debridement via Oblique Lateral Interbody Fusion Corridor Combined with Posterior Pedicle Screw Fixation in Treating Spontaneous Lumbar Infectious Spondylodiscitis: A Case Series.

OBJECTIVE: Surgery is indicated when antibiotic treatment fails in pyogenic spondylodiscitis, which is caused by pathogens such as the Staphylococcus species. The aim of the present study was to investigate the efficacy and safety of the oblique lateral interbody fusion (OLIF) corridor approach combined with posterior pedicle screw fixation for treating pyogenic spondylodiscitis. METHODS: This was a retrospective case series study. A total of 11 patients with an average age of 60.7 years (range, 40-70 years; 10 males and 1 females) with lumbar pyogenic spondylodiscitis who underwent single-stage debridement and reconstruction using the OLIF corridor combined with posterior pedicle screw fixation were recruited in our study from June 2016 to July 2017. All patients had single-level pyogenic spondylodiscitis between T12 and L5 . The baseline data, perioperative outcomes (operative time, intra-operative blood loss, and intra-operative complication), postoperative laboratory tests (erythrocyte sedimentation rate [ESR], C-reactive protein [CRP], white blood count [WBC], and tissue culture results), long-term complications (recurrence, fixation failure, and bony non-fusion rates), and duration of antibiotic administration were reviewed. Outcomes evaluated using a variety of scales including visual analog scale (VAS) score and Oswestry disability index (ODI), were compared pre-operatively and post-operatively. RESULTS: The mean follow-up period of time was 18.3 months. The average operative time and intra-operative blood loss were 217.0 ± 91.91 min and 220.9 ± 166.10 mL, respectively. There were no intra-operative complications, except in 1 patient who encountered somatosensory evoked potentials changes and 1 patient who had motor evoked potentials changes, both without post-surgery neurological deficits. Causative organisms were identified in 4 patients: Staphylococcus aureus in 1 patient and Streptococcus in 3 patients. At approximately 8.8 weeks after surgery, WBC, CRP, and ESR had returned to normal levels. All patients were pain free with no recurring infection. There was no fixation failure during follow up. Solid bony fusions were observed in all cases within 6 months. At the final follow up, the mean VAS (0.6 ± 0.69) and ODI (14.4 ± 4.27) were significantly lower than those before surgery (P < 0.05). CONCLUSION: One-stage debridement with autogenous iliac bone graft through the OLIF corridor combined with posterior pedicle screw fixation is effective and safe for single-level spontaneous lumbar pyogenic spondylodiscitis after antibiotic treatment fails.

[Clinical value of minimally invasive posterior lumbar interbody fusion assisted by X-Tube system in the treatment of low back disorders].

OBJECTIVE: To evaluate the clinical outcomes of minimally invasive posterior lumbar interbody fusion (PLIF) assisted by X-Tube system for the management of degenerative lumbar diseases. METHODS: A total of 31 patients, 17 male and 14 female with ages from 38 to 75 (average 54.2 years), underwent minimally invasive PLIF assisted by the X-Tube system from May 2005 to March 2006. The index diagnosis was lumbar spondylolisthesis in 14 cases, spinal stenosis in 8 cases, separation of the posterior ring apophysis in 5 cases, intervertebral space stenosis with disk herniation in 4 cases. Before operation, conservative management for at least 6 months was proved to be failure in all these patients. The operative duration and blood loss were estimated . The changes of postoperative serum level of creatinine kinase was measured as well, and compared with the control group of 31 cases who were managed with traditional open PLIF operation during the same period at our department. The clinical functional outcomes were evaluated according to Oswestry disability questionnaire. RESULTS: The operation lasted for 140-225 min, with a mean duration of (176 +/- 22) min. Blood loss during the operation was 270-750 ml, with a mean of (406 +/- 96) ml. Postoperative serum level of creatinine kinase was obviously lower in minimally invasive PLIF cases than in the open control cases. Although 2 pedicle screws in 2 cases were not in ideal position, there was no nerve root irritation or fixation failure and hence no revision was required. One case with spinal stenosis complained of numbness in the area dominated by left L5 nerve root after operation, but the symptom was relieved within 2 weeks through conservative management. All the 31 patients were followed up for 7-17 months, with a mean duration of 12.2 months. Lumbar radiography, and three-dimensional CT reconstruction in some cases, was performed and revealed solid fusion of the surgical segments half a year after the operation. The average Oswestry scores decreased from preoperative 40.6 +/- 5.1 to 17.4 +/- 6.5 at the first postoperative day and to 9.5 +/- 4.0 at the final follow-up. The outcome of this operation were rated as excellent. CONCLUSIONS: Minimally invasive PLIF assisted by X-Tube system has the characteristics of less blood loss, tissue trauma and operative time, quick recovery and bony fusion. The short-term outcomes are excellent.

Complications and Prevention Strategies of Oblique Lateral Interbody Fusion Technique.

OBJECTIVE: To analyze the early complications and causes of oblique lateral interbody fusion, and put forward preventive measures. METHODS: There were 235 patients (79 males and 156 females) analyzed in our study from October 2014 to May 2017. The average age was 61.9 ± 0.21 years (from 32 to 83 years). Ninety-one cases were treated with oblique lateral interbody fusion (OLIF) alone (OLIF alone group) and 144 with OLIF combined with posterior pedicle screw fixation through the intermuscular space approach (OLIF combined group). In addition, 137/144 cases in the combined group were primarily treated by posterior pedicle screw fixation, while the treatments were postponed in 7 cases. There were 190 cases of single fusion segments, 11 of 2 segments, 21 of 3 segments, and 13 of 4 segments. Intraoperative and postoperative complications were observed. RESULTS: Average follow-up time was 15.6 ± 7.5 months (ranged from 6 to 36 months). Five cases were lost to follow-up (2 cases from the OLIF alone group and 3 cases from the OLIF combined group). There were 7 cases of vascular injury, 22 cases of endplate damage, 2 cases of vertebral body fracture, 11 cases of nerve injury, 18 cases of cage sedimentation or cage transverse shifting, 3 cases of iliac crest pain, 1 case of right psoas major hematoma, 2 cases of incomplete ileus, 1 case of acute heart failure, 1 case of cerebral infarction, 3 case of left lower abdominal pain, 9 cases of transient psoas weakness, 3 cases of transient quadriceps weakness, and 8 cases of reoperation. The complication incidence was 32.34%. Thirty-three cases occurred in the OLIF alone group, with a rate of 36.26%, and 43 cases in the group of OLIF combined posterior pedicle screw fixation, with a rate of 29.86%. Fifty-seven cases occurred in single-segment fusion, with a rate of 30.0% (57/190), 4 cases occurred in two-segment fusion, with a rate of 36.36% (4/11), 9 cases occurred in three-segment fusion, with a rate of 42.86% (9/21), and 6 cases occurred in four-segment fusion, with a rate of 46.15% (6/13). CONCLUSION: In summary, OLIF is a relatively safe and very effective technique for minimally invasive lumbar fusion. Nonetheless, it should be noted that OLIF carries the risk of complications, especially in the early stage of development.

[The feature of experimental endplate fracture in lumbar spine and its related factors].

OBJECTIVE: To evaluate the feature of experimental endplate fracture in lumbar spine and its related factors. METHODS: Nineteen cadaveric lumbar motion segments aged 48 - 77 years were compressed by overload to fracture the endplate and dissected into isolated vertebrae to evaluate feature of their endplate failure. Before and after failure of endplate, radiographic tests were taken on every motion segment. The bone mineral density (BMD), bone mineral content (BMC) of the vertebral body and endplate were tested respectively before endplate fracture. RESULTS: Among 19 motion segments, 16 were fractured and accounted for 84.2% of all and fracture featured as stellate, step, depression and intrusion. Fracture concentrated on the center or anterior of superior endplate of the inferior vertebrae in one motion segment. Failure load of endplate was positively correlated with BMD, BMC of vertebral endplate. Within one vertebral body, the BMD and BMC of its superior endplate was markedly less than that of inferior endplate, on the other hand, the difference of BMD and BMC of endplate around one disc was opposite. CONCLUSIONS: Fractures usually concentrate on the center or anterior part of superior endplate of one vertebrae and are hard to be identified by conventional radiographic examination. Failure load of endplate is positively correlated with BMD, BMC of vertebral body and endplate. There might be certain relationship between feature of fracture and severity of disc degeneration.

Prevalence and Risk Factors of Deep Vein Thrombosis in Patients Undergoing Lumbar Interbody Fusion Surgery: A Single-Center Cross-Sectional Study.

This cross-sectional study was designed to obtain the current prevalence of deep vein thrombosis (DVT) and analyze related risk factors in patients undergoing lumbar interbody fusion. Medical record data were collected from Department of Spinal Surgery, The Third Hospital of Hebei Medical University, between July 2014 and March 2015. Both univariate analysis and binary logistic regression analysis were performed to determine risk factors for DVT. A total of 995 patients were admitted into this study, including 484 men and 511 women, aged from 14 to 89 years old (median 50, IQR 19). The detection rate of lower limb DVT by ultrasonography was 22.4% (223/995) in patients undergoing lumbar interbody fusion. Notably, average VAS (visual analog scale) score in the first 3 days after surgery in the DVT group was more than that in the non-DVT group (Z = -21.69, P < 0.001). The logistic regression model was established as logit P = -13.257 + 0.056*X1 - 0.243*X8 + 2.085*X10 + 0.001*X12, (X1 = age; X8 = HDL; X10 = VAS; X12 = blood transfusion; x = 677.763, P < 0.001). In conclusion, advanced age, high postoperative VAS scores, and blood transfusion were risk factors for postoperative lower limb DVT. As well, the logistic regression model may contribute to an early evaluation postoperatively to ascertain the risk of lower limb DVT in patients undergoing lumbar interbody fusion surgery.

Prevalence and risk factors of deep vein thrombosis in patients after spine surgery: a retrospective case-cohort study.

Deep vein thrombosis (DVT) is common seen in patients undergoing spine surgery. However, its prevalence and associated risk factors have not been well understood yet. This retrospective case-cohort study was designed to investigate risk factors for postoperative DVT using retrospectively collected data from department of spine surgery between 07/2013 and 07/2014. Univariate analysis and binary logistic regression analysis were used to determine risk factors for DVT. A total of 861 patients were admitted into DVT-associated analyses, including 410 males and 451 females, aged from 15 to 87 years old (median 54, IQR 18). Of them, 147 cases (17%) sustained postoperative DVT. DVT incidence was 15.9% in patients undergoing lumbar interbody fusion, 13.5% in patients treated by low-molecular-weight heparin (LMWH), while only 8.1% in patients without LMWH. However, it revealed no significant difference between LMWH group and non-LMWH group (χ(2) = 1.933, p = 0.164). Logistic regression equation was logit P = -4.09 + 0.05*X1 - 0.55*X2 + 0.41*X3 + 1.41*X7, (X1 = age; X2 = regions; X3 = hypertension; X7 = D-dimer). In this study, LMWH prophylaxis after spine surgery proved ineffective. Advanced age, D-dimer and hypertension have proved to be the risk factors for postoperative DVT in patients undergoing spine surgery.

[Modified Stoppa approach in treatment of bilateral pubic branch fractures].

OBJECTIVE: To investigate the feasibility and effectiveness of modified Stoppa approach in treatment of bilateral pubic fractures of pelvic. METHODS: The therapeutic effects of 16 patients with bilateral pubic fractures treated through the modified Stoppa approach from January 2010 to January 2014 were summarized and analyzed, involved 11 males and 5 females with an average age of 40.5 years old ranging from 17 to 59 years. According to Tile classification, there were 8 patients with type A, 6 with type B and 2 with type C. For 16 pelvic fractures, the modified Stoppa approach was used exclusively 11 cases, in combination with the iliac fossa approach in 4 cases, and in combination with the posterior approach in 1 case. The operation incision length, operation time , intra-operative blood loss and postoperative complications were observed. The fracture reduction and post-operative function were assessed by Matta criteria and Majeed system respectively. RESULTS: The incision length of the modified Stoppa approach ranged from 8 to 10 cm (averaged in 9 cm). The operation time ranged from 75 to 135 minutes (averaged in 95 minutes). The intra-operative blood loss ranged from 400 to 900 ml (averaged in 600 ml). Sixteen patients were followed up from 7 to 18 months (averaged in 12.5 months). The fractures were all healed, the fracture healing time was 2.7 to 5 months (means 3.1 months). There were no infections, ectopic ossification, screw loosening, plate breakage and lateral ventral syndrome. According to Matta criteria for pubic fracture reduction, the result was excellent in 9 cases, good in 6, fair in 1. The Majeed function scores at 6 months after operation was 85.32±8.50; the result was excellent in 8 cases, good in 6 cases, fair in 2 cases. CONCLUSION: The modified Stoppa approach has characteristics of convenience and directness of incisions, clear operation field, easy reduction, few complications and fast recovery , it is an ideal choice in surgical treatment of bilateral pubic fractures.