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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. [ABSTRACT FROM AUTHOR]

Objective The purpose of this review was to investigate whether cervical total disc arthroplasty (CTDA) preserves motion of the treated level and what its effect is on adjacent segments. Methods Relevant published reports were collected from PubMed, Medline and Cochrane library. The original studies were considered eligible only if the range of motion ( ROM) of the index or adjacent level had been investigated. A meta-analysis was then performed on the collected data. Statistical heterogeneity across the various trials was tested using Cochran's Q statistic and I2; in the case of heterogeneity, a random effect model was used. Results The weighted mean differences ( WMDs) of the index level were 0.34 (95% confidence interval [ CI], −0.53∼1.21, P = 0.440) and 0.23 (95% CI, −1.92∼2.38, P = 0.834) in all included studies and randomized control trials ( RCTs), respectively. The WMDs of the cranial adjacent levels, caudal adjacent levels and whole cervical spines were 1.01 (95% CI, 0.55∼1.47, P = 0.000), 1.10 (95% CI, 0.61∼1.59, P = 0.000) and 3.40 (95% CI, −6.02∼12.82, P = 0.479), respectively. Conclusion These findings suggest that the protective effect against adjacent segment degeneration provided by cervical arthroplasty might not be as good as has been believed. Long-term supporting evidence is still needed. [ABSTRACT FROM AUTHOR]

The article discusses anterior decompression and reconstruction for lumbar burst fractures of a 32-year-old man fell from a height of 4 m 3 h prior to presenting with pain in his low back. The patient had limitations in lower extremity activity and he was positioned in a right lateral decubitus position after induction of general anesthesia.

The article presents a case study of a 58 year old woman who experiences lower back pain and neurogenic claudication for over a year. The patient is diagnosed with spondylolisthesis with lumbar stenosis and discusses the use of intervertebral disk prostheses in the treatment of spondylolisthesis. It mentions the use of this technique employed during surgery.

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. [ABSTRACT FROM AUTHOR]

The article presents a case study of a 45 year old female who had undergone posterior lumbar interbody fusion and have a history of degenerative disease of the lumbar spine in a local hospital with an initially satisfactory outcome. A SynFrame Retractor System (Synthes) was used to create a stable surgical field and allows a smaller skin incision.

The article presents the case history of a 63-year-old woman presented with ongoing low back pain and left leg radicular pain who had anterior decompression and strut grafting for adjacent segment disease. Adjacent segment disease (ASD) is said to be one of the most common complications of lumbar spine fusion.

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. [ABSTRACT FROM AUTHOR]

The approach-related morbidity resulting from iatrogenic erector spinae injury in posterior lumbar surgery has become an increasing concern for spine surgeons. Many studies have explained the injury mechanisms and reported new surgical approaches to prevent this iatrogenic injury from their own point of views, but there is still no systemic information for a thorough understanding of this iatrogenic erector spinae injury that may give spine surgeons practical advices in their individual operations. We consequently reviewed the literature on the anatomy of erector spinae, causes of injury, and relative minimally invasive approaches. We found that the local anatomic structures make the erector spinae vulnerable to injury during posterior lumbar surgery, especially the medial multifidus which is innervated only by the medial branch of the dorsal ramus, with no intersegmental nerve supply as in the other paraspinal muscles, and the injury factors mainly include dissection, retraction, denervation, and immobility. Studies suggest that the goal of prevention is to preserve the physiological structure of erector spinae and to avoid or limit the injury causes: approaches through spatium intermusculare and approaches with endoscope and tubular retractor system can prevent the erector spinae from injury by less dissection and retraction; non-fusion techniques may prevent the erector spinae from disuse atrophy by preserving the segmental motion and the adjacent erector spinae activity. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: A postoperative discal pseudocyst (PDP) is a cystic lesion that is formed in the operation area of the intervertebral disc, leading to recurrence or even worse symptoms. To our knowledge, to date, there is no research focusing specifically on PDP following percutaneous endoscopic interlaminar discectomy (PEID). Case presentation: We present the case of a 27‐year‐old man with L5S1 intervertebral disc herniation who was treated with PEID after failed conservative treatment. His leg pain was relieved immediately but reoccurred on the 40th day. MRI showed a PDP. Because loxoprofen and bedrest were ineffective and the patient was anxious, we performed a cystectomy. The patient's symptoms were significantly relieved, and a 6‐month follow up showed no recurrence both clinically and on MRI. Conclusion: A PDP is more likely to form using the interlaminar approach than the transforaminal approach. For patients with mental stress, severe pain, and neurological symptoms, surgery is suggested to remove the cyst. Discectomy cannot be performed when disc degeneration is mild. [ABSTRACT FROM AUTHOR]

Image 1 • An H 2 O 2 induced oxidative stress model of the endplate was successfully established in vitro as well as in vivo. • NAC alleviated cellular damage, abrogated catabolic effects and restored the redox status and cell viability in endplates. • The inhibitor of TAK1 reduced the expression of p-TAK1 and NLRP3, and ameliorated rat CEP degeneration in vivo. [ABSTRACT FROM AUTHOR]

Study Design: A rat model of multifidus muscles injury and atrophy after posterior lumbar spine surgery.Objective: We determined the effect of ascorbic acid (AA) on the postoperative multifidus muscles in rat model.Summary Of Background Data: Previous studies show oxidative stress and inflammation are two main molecular mechanisms in multifidus muscle injury and atrophy after posterior lumbar surgery. AA may have a protective effect in postoperative multifidus muscles.Methods: Rats were divided into sham surgery, control surgery, and surgery plus AA groups. Multifidus muscles of the control and AA groups were excised from the osseous structures. The muscles were retracted continuously for 2 hours. In the sham and AA groups, AA was administered via oral gavage daily in the first week. In each group, the oxidative stress was evaluated by measuring malondialdehyde (MDA) and Total superoxide dismutase (T-SOD). The inflammation, fat degeneration, or fibrosis of multifidus muscle were evaluated by quantitative real-time polymerase chain reaction (q-PCR), histology, or immunohistochemical analysis.Results: T-SOD activity was significantly lower in the control group than that in the AA group in the first week. MDA levels were significantly higher in the AA group. Interleukin-6 and tumor necrosis factor-α in multifidus muscles also showed significant differences when treated with AA. The inflammation score on histology was significantly lower in the AA group postoperatively in the first week. In the long run, marker genes for fibrosis and fat degeneration, and fibrosis and fat degeneration scores, were significantly lower in the AA than the control group on days 14 and 28 postoperatively.Conclusion: In conclusion, AA attenuated the oxidative stress and inflammation response in the postoperative multifidus muscles, and remarkable differences were observed from the histological assessment and related marker genes expression. Our results provided important insight into the anti-inflammatory and anti-oxidative effects of AA in the postoperative multifidus muscles.Level Of Evidence: N/A. [ABSTRACT FROM AUTHOR]

Objective: Turnover of cartilage endplate extracellular matrix (ECM) may play an important role in disc degeneration and low back pain (LBP). However, the expression pattern of pro‐inflammatory factors, matrix metalloproteinases (MMP), and tissue inhibitors of metalloproteinases (TIMP) in the cartilage endplates (CEP) of intervertebral discs (IVD) is not understood. We aimed to examine the transcriptional levels of MMP, TIMP, and interleukins (IL), and the correlations between them. Methods: Thirty degenerated cartilage endplate samples from patients with LBP who underwent lumbar fusion surgery were included in the degenerated group. Ten patients without LBP history who underwent lumbar surgery because of vertebral burst fractures were included in the control group. The degenerative severity of the samples was evaluated by MRI, and hematoxylin–eosin and safranin O‐fast green (SO‐FG) staining. Real‐time polymerase chain reaction (RT‐PCR) was used to detect the mRNA levels of MMP‐1, MMP‐3, MMP‐9, MMP‐13, TIMP‐1, TIMP‐2, TIMP‐3, IL‐1α, IL‐1β, and IL‐6. The correlations between the levels of these genes were tested using Spearman's rho test. Results: Hematoxylin–eosin and SO‐FG staining confirmed a decrease in cell number and proteoglycans in the degenerated cartilage endplate. MRI showed significant signal changes in degenerated cartilage endplates. Patients in the degenerated group showed a higher rate of endplate Modic changes when compared with the control group. MMP‐3, MMP‐9, TIMP‐3, IL‐1α, and IL‐1β were elevated with statistical significance, while MMP‐1, MMP‐13, TIMP‐1, TIMP‐2, and IL‐6 were changed without statistical significance or remained unchanged. Expression of MMP‐3 was positively correlated with IL‐1α (Spearman coefficient, 0.486; P < 0.05); expression of TIMP‐3 was positively correlated with MMP‐9, IL‐1α, and IL‐1β (Spearman coefficient, 0.577, 0.407, and 0.571, respectively; P < 0.05). Conclusion: MMP‐3, MMP‐9, TIMP‐3, IL‐1α, and IL‐1β may play a role in the process of cartilage endplate degeneration. MMP‐3 may be regulated by IL‐1α, and TIMP‐3 might be associated with MMP‐9 and regulated by IL‐1α and IL‐1β. [ABSTRACT FROM AUTHOR]

Objective: To compare postoperative imaging results, clinical outcomes and complications between the multifidus muscle bundle (MMB) approach and the conventional open (CO) approach in one‐level posterior lumbar interbody fusion (PLIF). Methods: Based on the inclusion and exclusion criteria, 201 of 351 patients in our hospital were enrolled in this prospective study and underwent MMB‐PLIF or CO‐PLIF randomly: 111 patients in the MMB‐PLIF group and 90 patients in the CO‐PLIF group. A total of 100 patients failed to be followed up in the following 7–9 years. Therefore, in this study, 52 patients of the MMB group and 49 patients of the CO group were included. We evaluated the differences in terms of multifidus atrophy rate, intervertebral disc height and segmental lordosis restoration of the operation segment, lumbar lordosis restoration, fusion rate, visual analogue scale (VAS) for back and leg pain, Oswestry disability index (ODI), complication rates, and patient satisfaction rates between the two groups. Correlation between multifidus muscle degeneration and the incidence of complications was investigated, and we compared the multifidus muscle degeneration rate between patients with or without intractable back pain or adjacent segment degeneration. Results: There were no significant differences in age, sex, body mass index (BMI), diagnosis, segments distribution, and mean follow‐up time between the MMB‐PLIF group and the CO‐PLIF group. In addition, no differences regarding sex, age, or BMI were found between the lost follow‐up group and the successful follow‐up group. In regard to imaging and clinical evaluation, at the final follow‐up, there were significant differences in multifidus atrophy rates (27.0% ± 6.8% vs 38.7% ± 10.9%), lumbar lordosis restoration (4.6° ± 2.5° vs 3.0° ± 1.9°), postoperative VAS for back pain (1.1 ± 0.9 vs 1.8 ± 1.2), ODI (7.7 ± 5.0 vs 12.4 ± 6.7), and patient satisfaction rates (86.5% vs 61.2%) between MMB‐PLIF and CO‐PLIF groups. However, there were no significant differences in segmental lordosis, intervertebral height restoration, postoperative VAS for leg pain or fusion rate between the two groups. In regards to complications, there were significant differences in the incidence of adjacent segment degeneration (3.8% vs 14.3%), intractable back pain (3.8% vs 22.4%), and residual neurological symptoms (5.8% vs 20.4%) between the two groups (P < 0.05) at the final follow‐up. In addition, patients with adjacent segment degeneration and intractable back pain were observed with more significant multifidus muscle atrophy than those without these two complications (31.9% ± 1.1% vs 39.6% ± 2.1% and 30.9% ± 1.1% vs 42.8% ± 2.1%). Conclusion: Compared with CO‐PLIF, MMB‐PLIF had advantages in relation to protection of the multifidus muscle, better maintenance of lumbar lordosis, reduced lower back pain and ODI score, fewer complications, and a higher patient satisfaction rate. Protection of the multifidus muscle in lumbar surgery is an important aspect of minimally invasive surgery. [ABSTRACT FROM AUTHOR]

Intervertebral disc degeneration (IVDD) is a multifactorial disease and responsible for many spine related disorders, causes disability in the workforce and heavy social costs all over the world. Honokiol, a low molecular weight natural product, could penetrate into and distribute in IVDs to achieve therapeutic effect in a rat tail model. Therefore, the present study was undertaken to examine the antiinflammatory, antioxidation and IVD-protective effect of honokiol using nucleus pulposus cells and investigate its mechanisms to provide a new basis for future clinical treatment of IVDD. In the current study, we demonstrated that honokiol inhibits the H 2 O 2 -induced apoptosis (caspase-9, caspase-3, and bax), levels of oxidative stress mediators (ROS, MDA), expression of inflammatory mediators (Interleukin-6, COX-2, and iNOS), major matrix degrading proteases (MMP-3, MMP-13, ADAMTS5, and ADAMTS4) associated with nucleus pulposus degradation. Furthermore, we found nucleus pulposus protective ability of honokiol by up-regulating extra cellular matrix anabolic factors like type II collagen (Col II) and SOX9 in nucleus pulposus. We also found that honokiol suppressed the phosphorylation of NF-kB and JNK, and activation of TXNIP-NLRP3 inflammasome in H 2 O 2 -stimulated nucleus pulposus cells, thereby inhibiting the activation of downstream inflammatory mediators such as Interleukin-1β. Furthermore, honokiol showed a cartilage protective effect in the progression of IVDD in a rat model induced by puncture. Thus, our results demonstrate that honokiol inhibited the H 2 O 2 induced apoptosis, oxidative stress, and inflammatory responses through the depression of TXNIP/NLRP3/caspase-1/ Interleukin − 1β signaling axis and the activation of NF-kB and JNK. Honokiol possess nucleus pulposus protective properties and may be of value in suppressing the pathogenesis of IVDD. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Study Design: Experimental study evaluated magnetic resonance imaging (MRI) and histologic changes in the multifidus muscle after anterior spinal fusion.Objective: To determine the effect of spinal fusion on the multifidus muscle in an anterior rabbit model through the use of MRI and histologic evaluation.Summary Of Background Data: Retraction and splitting approach are known to be important factors in postoperative injury and atrophy of the multifidus muscle. The effect and possible mechanism of spinal fusion as an independent factor remains unknown.Methods: Thirty-six New Zealand white rabbits were divided into two groups. Animals in the fusion group underwent two-level anterior spinal fusion whereas those in the control group underwent similar surgery without spinal fusion. The status of the multifidus muscle was evaluated with MRI and histological analysis at preoperative, 3 weeks, 6 weeks, 3 months, 6 months, and 12 months postoperatively.Results: All rabbits in the fusion group achieved solid fusion. The mean T1-weighted and T2-weighted signal intensity ratios of gross multifidus to psoas muscles were all approximately 1.0 postoperatively, with no remarkable difference between the groups. The mean lesser diameter of myofibrils in either group did not significantly differ between the preoperative and postoperative specimens. There was no significant fibrotic change or fatty degeneration for either group. Decrease in acetylcholine activity or granular degeneration of the neuromuscular junction were not observed, and normal shape and size were found in nearly all samples at all time points in both groups (P > 0.05).Conclusion: After two-segment anterior spinal fusion, multifidus atrophy was not observed throughout a 12-month follow up. The rabbit model of anterior fusion is better suited to study the effect of fusion alone on the status of the multifidus muscle.Level Of Evidence: 3. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: Modic changes are the MRI signal changes of degenerative lumbar vertebral endplate and which lead to or accelerate intervertebral disc degeneration. NLRP3, caspase-1, and interleukin-1β (IL-1β) play a pivotal role in the pathogenesis of many inflammatory diseases, such as osteoarthritis. However, the roles of IL-1β and its activators caspase-1 and NLRP3 are unclear in the degenerative endplate.Questions/purposes: We asked: (1) What are the degenerative changes of the histologic features and chondrogenic markers' gene expressions between the cartilaginous endplates of patients with Modic changes and trauma (control)? (2) How does the NLRP3/caspase-1/IL-1β axis in the cartilaginous endplates of patients with Modic changes compare with control (trauma) specimens?Methods: Surgical specimens of cartilaginous endplates were divided into Modic changes (n = 56) and the trauma control (n = 16) groups. Hematoxylin and eosin and safranin O staining of cartilaginous endplate tissues were done to evaluate the extracellular matrix. Reverse transcription-polymerase chain reaction was performed on these tissues to investigate mRNA expression of type II collagen (Col II), SOX-9, matrix metalloproteinase-3, and a disintegrin like and metalloproteinase thrombospondin type I motifs-5. NLRP3, caspase-1, and IL-1β were evaluated by reverse transcription-polymerase chain reaction and immunohistochemistry.Results: Hematoxylin and eosin and safranin O staining showed the extracellular matrix degraded in the cartilaginous endplates of patients with Modic changes but not in the control cartilaginous endplates. Chondrogenic Col II (p = 0.024) and SOX9 (p = 0.053) were downregulated in the Modic changes group compared with the control group. In contrast to the control group, the transcriptional levels of NLRP3 (p < 0.001), caspase-1 (p = 0.054), and IL-1β (p = 0.001) were all upregulated in the Modic changes group.Conclusions: The expression of NLRP3, caspase-1, and IL-1β was upregulated in the patients with low back pain and Modic changes on MRI compared with patients with vertebral burst fracture without degenerative changes on MRI. The data suggest the NLRP3/caspase-1/IL-1β axis may be implicated in lumbar cartilaginous endplate degeneration.Clinical Relevance: The NLRP3/caspase-1/IL-1β axis is active in cartilaginous endplates of patients with Modic changes and inflammatory cascades can exacerbate the cartilaginous endplate degeneration which may act as a trigger for intervertebral disc degeneration and low back pain. If these findings can be confirmed by others, we hope that new and effective therapy could be developed directed against this target. [ABSTRACT FROM AUTHOR]

A rare case of atlantoaxial lateral mass joint interlocking secondary to traumatic posterolateral C1,2 complete dislocation associated with type II odontoid fracture is herein reported and the impact of atlantoaxial joint interlocking on fracture reduction discussed. A 72-year-old man presented with traumatic atlantoaxial lateral mass joint interlocking without spinal cord signal change, the diagnosis being confirmed by radiography and 3-D reconstruction digital anatomy. Posterior internal fixation was performed after failure to achieve closed reduction by skull traction. After many surgical attempts at setting had failed because of interlocking of the lateral mass joints, reduction was achieved by compressing the posterior parts of the atlantal and axial screws. Odontoid bone union and C1,2 posterior bone graft fusion were eventually obtained by the 12-month follow-up. The patient had a complete neurological recovery with no residual neck pain or radiculopathy. [ABSTRACT FROM AUTHOR]

Objective To investigate the midterm outcomes of unilateral pedicle screws combined with contralateral gunsight-guided translaminar facet screw fixation and interbody fusion for treatment of single-segment lower lumbar vertebral disease. Methods A total of 78 patients with various lower lumbar single-segment vertebral diseases were treated in our department from January 2008 to December 2011. There were 21 males and 57 females, with an average age of 52.5 years, including lumbar disc degeneration (28 cases), local recurrence of lumbar disc herniation (9 cases), huge lumbar disc herniation (11 cases), lumbar disc herniation with spinal stenosis (13 cases), and lumbar degenerative spondylolisthesis (degree I) (17 cases). All patients were treated by unilateral pedicle screws in the median incision combined with contralateral gunsight-guided translaminar facet screw fixation and interbody fusion. Results No wound infection or skin necrosis around incision was observed after operation. No leakage of cerebrospinal fluid or nerve injury occurred during and after operation. Excepting 4 cases, 74 cases were followed up for 18-60 months, averaged 33.5 months. All but one patient (98.6%) received interbody fusion. The intervertebral height of the indexed level was well restored and maintained. At final follow-up. During follow-up, there was no screw loosening or pedicle fracture observed. No apparent degeneration of adjacent segments. The mean Japanese Orthopaedic Association ( JOA) scores was increased significantly from 12.79 ± 2.12 preoperatively to 25.8 ± 2.87 at the final follow-up. Conclusion Unilateral pedicle screw fixation combined with contralateral translaminar facet screw fixation and interbody fusion showed good mid-term outcomes in the treatment of single-segment lower lumbar vertebral disease, and can be used as an optimal choice for fixation and fusion of some single-segment lower lumbar vertebral diseases. [ABSTRACT FROM AUTHOR]

Background context: The high-intensity zone (HIZ) on magnetic resonance imaging (MRI) has been studied for more than 20 years, but its diagnostic value in low back pain (LBP) is limited by the high incidence in asymptomatic subjects. Little effort has been made to improve the objective assessment of HIZ. Purpose: To develop quantitative measurements for HIZ and estimate intra- and interobserver reliability and to clarify different signal intensity of HIZ in patients with or without LBP. Study design: A measurement reliability and prospective comparative study. Patient sample: A consecutive series of patients with LBP between June 2010 and May 2011 (group A) and a successive series of asymptomatic controls during the same period (group B). Outcome measures: Incidence of HIZ; quantitative measures, including area of disc, area and signal intensity of HIZ, and magnetic resonance imaging index; and intraclass correlation coefficients (ICCs) for intra- and interobserver reliability. Methods: On the basis of HIZ criteria, a series of quantitative dimension and signal intensity measures was developed for assessing HIZ. Two experienced spine surgeons traced the region of interest twice within 4 weeks for assessment of the intra- and interobserver reliability. The quantitative variables were compared between groups A and B. Results: There were 72 patients with LBP and 79 asymptomatic controls enrolling in this study. The prevalence of HIZ in group A and group B was 45.8% and 20.2%, respectively. The intraobserver agreement was excellent for the quantitative measures (ICC=0.838–0.977) as well as interobserver reliability (ICC=0.809–0.935). The mean signal of HIZ in group A was significantly brighter than in group B (57.55±14.04% vs. 45.61±7.22%, p=.000). There was no statistical difference of area of disc and HIZ between the two groups. The magnetic resonance imaging index was found to be higher in group A when compared with group B (3.94±1.71 vs. 3.06±1.50), but with a p value of .050. Conclusions: A series of quantitative measurements for HIZ was established and demonstrated excellent intra- and interobserver reliability. The signal intensity of HIZ was different in patients with or without LBP, and significant brighter signal was observed in symptomatic subjects. [ABSTRACT FROM AUTHOR]

P-glycoprotein (P-gp) is present in various tissue cells, required for the pumping of lipophilic drugs (including glucocorticoids) out of cells. We hypothesized that polymorphisms in the P-gp encoding gene (multidrug-resistant transporter-1 [ MDR1]) are related to individual differences in glucocorticoid sensitivity and the development of glucocorticoid-induced avascular necrosis of the femoral head (GANFH). In this case-control study, we genotyped three known single-nucleotide polymorphisms (SNPs: C1236T, G2677T/A, and C3435T) within the MDR1 gene in 662 Chinese subjects. Statistically significant differences between GANFH patients and either healthy controls or glucocorticoid-resistant patients (non-GANFH) were found for the T allele or TT genotype of C3435T. The haplotype TTT, composed of these three SNPs, exhibited a significant association with the disease. No associations were identified between C1236T or G2677T/A and GANFH. Our results suggest that the C3435T polymorphism of the MDR1 gene is associated with susceptibility to GANFH in a Chinese population. [ABSTRACT FROM AUTHOR]

The quantitative real-time polymerase chain reaction (qRT-PCR) is one of the most widely used methods to study gene expression profiles, and it requires appropriate normalization for accurate and reliable results. Although several genes are commonly used as reference genes (such as GAPDH, ACTB, and 18S rRNA), they are also regulated and can be expressed at varying levels. In this study, we evaluated twelve well-known reference genes to identify the most suitable housekeeping gene for normalization of qRT-PCR in human lumbar vertebral endplate with Modic changes, by using the geNorm, NormFinder, and BestKeeper algorithms. Our results showed that the rarely-used SDHA was the most stable single reference gene, and a combination of three, SDHA, B2M, and LDHA, was the most suitable gene set for normalization in all samples. In addition, the commonly-used genes, GAPDH, ACTB and 18S rRNA, were all inappropriate as internal standards. The rankings of reference genes for the three types of Modic change differed, although SDHA and RPL13A uniformly ranked in the first and last position, respectively. Further simulated expression analysis validated that the arbitrary use of a reference gene could lead to the misinterpretation of data. Our study confirmed the necessity of exploring the expression stability of potential reference genes in each specific tissue and experimental situation before quantitative evaluation of gene expression by qRT-PCR. [ABSTRACT FROM AUTHOR]

Objective To review and analyze cage migration and related risk factors in patients who have undergone transforaminal lumbar interbody fusion ( TLIF). Methods A retrospective study was conducted to review the complications of cage migration in 512 patients who had undergone a TLIF procedure from January 2010 to June 2011 in five spinal centers. In all, 263 men and 249 women with a mean age of 54.7 years were included. All patients were followed up at 3, 6 and 12 months after the procedure. The clinical outcomes were evaluated by visual analogue scores, the Oswestry disability index, plain radiography and three-dimensional CT scanning to analyze the incidence of, and risk factors related to, cage migration. Results Cage migration was found in 6 of the 512 patients (1.17%). Significant differences were found between all pairs of centers. Different shapes and sizes of cages had different incidences of migration. Analysis showed that rectangular-shaped cages had a significantly greater incidence of cage migration (3.11%, 5/161) than did kidney-shaped cages (0.28%, 1/351; P < 0.05). Small cages had a tendency to more frequent post-operative cage migration (5.13%, 4/78) than did large cages (0.46%, 2/434; P < 0.05). Double segment TLIF cages migrated more frequently (5.75%, 5/87) than did mono-segment cages (0.24%, 1/425; P < 0.05)). Furthermore, when the adjacent endplates were of linear type, the cages migrated much more frequently (3.50%) than when they were of concave-concave type (0.27%; P < 0.05). Conclusion Cage size, shape, number of fused segments and adjacent endplate shape might be risk factors for cage migration in addition to surgical technique, disc height and bone mineral density. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Osteoclasts play an important role in diseases involving bone loss. In this study, we assessed the effect of a plant-derived natural alkaloid (lycorine, or LY) on osteoclastogenesis in vitro and in vivo. Our in vitro study showed that receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis could be inhibited by LY; this effect was due to inhibition of mitogen-activated protein kinase (MAPK) signalling via MAP kinase kinases (MKKs). The MAPK agonist anisomycin could partially rescue the inhibitory effect of LY. Furthermore, LY also played a protective role in both a murine ovariectomy (OVX)-induced osteoporosis model and a titanium particle-induced osteolysis model. These results confirmed that LY was effective in preventing osteoclast-related diseases in vivo. In conclusion, our results show that LY is effective in suppressing osteoclastogenesis and therefore could be used to treat OVX-induced osteoporosis and wear particle-induced osteolysis. [ABSTRACT FROM AUTHOR]

Study Design: This study investigated the expression of 2 types of ADAMTS in human intervertebral cartilage endplate (CEP) and related mechanisms concerning tumor necrosis factor α (TNF-α)-induced nuclear factor κB signaling pathway. Objective: To determine which type of ADAMTS is more strongly expressed and the role of TNF-α in CEP. Summary Of Background Data: ADAMTS-4 and ADAMTS-5 were proven to be essential in the degeneration of articular cartilage and intervertebral disc. CEP is an important structure adjacent to the disc. However, the activities of ADAMTS in CEP are unclear. Methods: CEPs were obtained from subjects after spinal surgery and categorized as members of either the Modic change group or the control group. Sections of these tissues were stained with hematoxylin-eosin, safranin O, and immunohistochemistry procedures for ADAMTS-4, ADAMTS-5, and TNF-α. Transcriptional levels of aggrecan, type I collagen, type II collagen, type X collagen, ADAMTS-4, ADAMTS-5, and TNF-α were investigated by quantitative real-time polymerase chain reaction. In addition, the effect of TNF-α on ADAMTS-5 and its potential mechanisms are investigated in cultured bovine endplate chondrocytes in vitro. Results: Our data demonstrated that the degenerative changes associated with the expression of extracellular matrix proteins were correlated with increased levels of ADAMTS-5, but not ADAMTS-4, in the CEP of patients with Modic changes. The expression levels of TNF-α in the Modic change group were significantly increased, which was correlated with the enhanced expression of ADAMTS-5. Additional in vitro investigation confirmed that TNF-α could upregulate the expression of ADAMTS-5 by activating nuclear factor κB pathway in cultured bovine endplate chondrocytes. Conclusion: We conclude that the upregulation of TNF-α and ADAMTS-5, but not ADAMTS-4, may play an important role in degenerative CEP-induced low back pain. Level Of Evidence: N/A. [ABSTRACT FROM AUTHOR]

Study Design: A reliability study was conducted. Objective: To estimate the intra- and intermeasurement errors in the measurements of functional cross-sectional area (FCSA), density, and T2 signal intensity of paraspinal muscles using computed tomography (CT) scan and magnetic resonance imaging (MRI). Summary Of Background Data: CT scan and MRI had been used widely to measure the cross-sectional area and degeneration of the back muscles in spine and muscle research. But there is still no systemic study to analyze the reliability of these measurements. Methods: This study measured the FCSA and fatty infiltration (density on CT scan and T2 signal intensity on MRI) of the paraspinal muscles at L3-L4, L4-L5, and L5-S1 in 29 patients with chronic low back pain. Two experienced musculoskeletal radiologists and one superior spine surgeon traced the region of interest twice within 3 weeks for measurement of the intra- and interobserver reliability. Results: The intraclass correlation coefficients (ICCs) of the intra-reliability ranged from fair to excellent for FCSA, and good to excellent for fatty infiltration. The ICCs of the inter-reliability ranged from fair to excellent for FCSA, and good to excellent for fatty infiltration. There were no significant differences between CT scan and MRI in reliability results, except in the relative standard error of fatty infiltration measurement. The ICCs of the FCSA measurement between CT scan and MRI ranged from poor to good. Conclusion: The reliabilities of the CT scan and MRI for measuring the FCSA and fatty infiltration of the atrophied lumbar paraspinal muscles were acceptable. It was reliable for using uniform one image method for a single paraspinal muscle evaluation study. And the authors preferred to advise the MRI other than CT scan for paraspinal muscles measurements of FCSA and fatty infiltration. [ABSTRACT FROM AUTHOR]