Modified Hidden Blood Loss Based on Drainage in Posterior Surgery on Lumbar Stenosis Syndrome with Rheumatoid Arthritis.

OBJECTIVE: Publications on hidden blood loss (HBL) after posterior lumbar interbody fusion (PLIF) for lumbar spine stenosis syndrome (LSS) have been reported, but the modified HBL (mHBL) was different from HBL obtained by classical formula and there are few studies on lumbar spine hemorrhage with rheumatoid arthritis (RA). Therefore, the aim of our study is to respectively evaluate the importance of hidden blood loss (HBL) and modified HBL (mHBL) after posterior lumbar interbody fusion (PLIF) in patients diagnosed with LSS and RA, to explore the correlation between RA activity and HBL as well as mHBL. METHODS: A total of 61 patients (nine males and 52 females) diagnosed with LSS and RA who underwent PLIF were included. Data contained demographics, RA-related parameters such as duration of RA, Steinbrocker classification (used to evaluated RA activity), the disease-modifying anti-rheumatic drugs (DMARDs), osteoporosis and total knee arthroplasty; operation and hemorrhage parameters. Then HBL and mHBL were calculated by Gross formula and modified formula, respectively. Subgroup analysis on HBL and mHBL was performed based on gender, age (≤60 years and ˃60 years), different number of surgical segments (single segment, double segment, and ≥3 segments), and taking DMARDs or not. ANOVA analysis was performed on HBL and mHBL in different surgery segment number and Steinbrocker classification of RA. Independent sample t-test was used in comparison of gender and age, as well as in comparison between HBL and mHBL based on whether the patient took DMARDs or not. Furthermore, paired t-test was used to compare the volume between HBL and mHBL. RESULTS: The mean age and duration of RA was 65.2 ± 9.3 years and 14.3 ± 10.7 years, respectively. There were 13 grade I cases, 34 grade II cases, and 14 grade III cases as assessed by Steinbrocker classification and the most common anti-RA drugs were DMARDs (57.4%). The mean intraoperative bleeding, drainage, and blood loss in drainage (DBL) was 453.3 ± 377.8 mL, 489.1 ± 253.8 mL, and 304.6 ± 156.3 mL, respectively. There was no difference on HBL and mHBL in gender. HBL and mHBL was larger in patients over 60 years (P = 0.040 and P = 0.023). There were differences in intraoperative blood loss, drainage, and DBL based on different number of segments but not in HBL and mHBL, or on Steinbrocker classification. DBL was lower in DMARDs group than non-drugged group (P = 0.03), while HBL and mHBL were both of no significance. The comparison of HBL and mHBL showed statistical difference (P < 0.001), suggesting that mHBL volume is larger than HBL. CONCLUSIONS: Patients diagnosed as LSS with RA have amounts of HBL or mHBL after PLIF. HBL or mHBL is not associated with RA activity, which may not increase in RA patients compared with common ones. Taking DMARDs may reduce postoperative DBL. The fact that mHBL is larger than HBL provides an all-round basis for measuring factual HBL.

Blood-Spinal Cord Barrier in Spinal Cord Injury: A Review.

The blood-spinal cord barrier (BSCB), a physical barrier between the blood and spinal cord parenchyma, prevents the toxins, blood cells, and pathogens from entering the spinal cord and maintains a tightly controlled chemical balance in the spinal environment, which is necessary for proper neural function. A BSCB disruption, however, plays an important role in primary and secondary injury processes related to spinal cord injury (SCI). After SCI, the structure of the BSCB is broken down, which leads directly to leakage of blood components. At the same time, the permeability of the BSCB is also increased. Repairing the disruption of the BSCB could alleviate the SCI pathology. We review the morphology and pathology of the BSCB and progression of therapeutic methods targeting BSCB in SCI.

Roles of extra-cellular signal-regulated protein kinase 5 signaling pathway in the development of spinal cord injury.

BACKGROUND: In consideration of characteristics and functions, extra-cellular signal-regulated protein kinase 5 (ERK5) signaling pathway could be a new target for spinal cord injury (SCI) treatment. Our study aimed to evaluate the roles of ERK5 signaling pathway in secondary damage of SCI. METHODS: We randomly divided 70 healthy Wistar rats into five groups: ten in the blank group, 15 in the sham surgery + BIX02188 (sham + B) group, 15 in the sham surgery + dimethyl sulfoxide (DMSO; sham + D) group, 15 in the SCI + BIX02188 (SCI + B) group, and 15 in the SCI + DMSO (SCI + D) group. BIX02188 is a specific inhibitor of the ERK5 signaling pathway. SCI was induced by the application of vascular clips (with the force of 30 g) to the dura on T10 level, while rats in the sham surgery group underwent only T9-T11 laminectomy. BIX02188 or DMSO was intra-thecally injected at 1, 6, and 12 h after surgery or SCI. Spinal cord samples were taken for testing at 24 h after surgery or SCI. RESULTS: Expression of phosphorylated-ERK5 (p-ERK5) significantly increased after SCI. Application of BIX02188 indeed inhibited ERK5 signaling pathway and reduced the degree of spinal cord tissue injury, neutrophil infiltration and proinflammatory cytokine expression, nuclear factor-κB (NF-κB) activation and apoptosis (measured by TdT-mediated 2'-deoxyuridine 5'-triphosphate nick-end labeling, expression of Fas-ligand, BCL2-associated X [Bax], and B-cell lymphoma-2 [Bcl-2]). Double immunofluorescence revealed activation of ERK5 in neurons and microglia after SCI. CONCLUSION: ERK5 signaling pathway was activated in spinal neurons and microglia, contributing to secondary injury of SCI. Moreover, inhibition of ERK5 signaling pathway could alleviate the degree of SCI, which might be related to its regulation of infiltration of inflammatory cells and release of inflammatory cytokines, expression of NF-κB and cell apoptosis.

Biomechanical effect of bone resorption of the spinous process after single-segment interspinous dynamic stabilization device implantation: A finite element analysis.

This study aims to explore the influence of bone resorption of the spinous process after single-segment interspinous process device (IPD) implantation on the biomechanics of the lumbar spine.The 3D finite element model of the lumbar spine (L3-L5) was modified, and 2 models that simulated the presence and absence of bone resorption of the spinous process were developed using an IPD (Wallis). Its biomechanical effects, such as change in range of motion (ROM) and intervertebral disc and facet stress, were introduced at operative (L4/5) and adjacent (L3/4) levels.Compared with the INT model, the Wallis model and Wallis-BR model had similar ROMs in lateral flexion and rotation. However, the Wallis model had a lower L3-5 ROM in flexion (20.4% lower) and extension (26.4% lower), and L4-L5 ROM in flexion (74.1% lower) and extension (70.8% lower), while the overall ROM of the Wallis-BR model was greater than that of the Wallis model. The stress on the L3/L4 intervertebral disc and facets was similar for all 3 models. Compared with the INT model and Wallis-BR model, the stress on the L4/L5 intervertebral disc and facets under all movements significantly decreased in the Wallis model. The stress on the L5 process was greater than that on the L4 process in both the Wallis model and Wallis-BR model, and the load on the processes that underwent bone resorption was lower than that of the Wallis model.The function of the IPD slowly decreased with the occurrence of bone resorption of the interspinous process. This bone remodeling may be associated with high stress after IPD implantation.

Clinical and Radiologic Features of 3 Reconstructive Procedures for the Surgical Management of Patients with Bilevel Cervical Degenerative Disc Disease at a Minimum Follow-Up Period of 5 Years: A Comparative Study.

OBJECTIVE: To assess the mid-long-term follow-up of the safety and efficacy of anterior cervical discectomy and fusion (ACDF), cervical artificial disc replacement (CADR) and hybrid surgery (HS) for bilevel cervical degenerative disc disease (cDDD). METHODS: 77 patients who underwent ACDF, HS, and CADR were retrospectively reviewed. Clinical effects were evaluated based on Neck Disability Index (NDI), Visual Analog Scale (VAS), and Japanese Orthopedic Association (JOA) scores and the Odom criteria. Radiographic outcomes were evaluated, including cervical range of motion (ROM), ROM in the operative and adjacent segments, incidence of degeneration in the adjacent segments (ASD), and heterotopic ossification (HO). RESULTS: NDI, VAS, and JOA scores significantly improved in all patients after surgery without significant differences between groups. The excellent-to-good ratio in the Odom scale was 28/30 for the HS group, 30/33 for the ACDF group, and 13/14 for the CADR group. No significant differences in clinical outcomes or complication were found between groups (P > 0.05). Furthermore, the HS and CADR groups had less decreased ROM in the cervical and operative segments and less compensatory ROM in adjacent segments (P < 0.05). By contrast, the ACDF group had decreased ROM in the cervical and operative segments and significantly increased ROM in adjacent segments (P < 0.05). Moreover, the incidence of ASD was higher in the ACDF group, but the difference was not statistically significant (P > 0.05). HO was found in 10 patients (33.3%) in the HS group and 5 patients (35.7%) in the CADR group. CONCLUSION: HS was superior to ACDF with regard to equivalent clinical outcomes in the mid-long-term follow-up. Furthermore, HS was superior in the maintenance of ROM and had less impact on its adjacent segments. The efficacy of HS is similar to that of CADR.

Radiological Analysis of Thoracolumbar Junctional Degenerative Kyphosis in Patients with Lumbar Degenerative Kyphosis.

BACKGROUND: Thoracolumbar junction (TLJ) is the transitional area between the lower thoracic spine and the upper lumbar spine. Vertebral compression fractures and proximal junctional kyphosis following spine surgery often occur in this area. Therefore, the study of development and mechanisms of thoracolumbar junctional degeneration is important for planning surgical management. This study aimed to review radiological parameters of thoracolumbar junctional degenerative kyphosis (TLJDK) in patients with lumbar degenerative kyphosis and to analyze compensatory mechanisms of sagittal balance. METHODS: From January 2016 to March 2017, patients with lumbar degenerative kyphosis were enrolled in this radiographic study. Patients were divided into two groups according to thoracolumbar junctional angle (TLJA): the non-TLJDK (NTLJDK) group (TLJA <10°) and the TLJDK group (TLJA ≥10°). Complete spinopelvic radiographic parameters were analyzed and compared between two groups. Pearson or Spearman correlation coefficients and independent two-sample t-test or Mann-Whitney U-test were used. RESULTS: A total of 77 patients with symptomatic sagittal imbalance due to lumbar degenerative kyphosis were enrolled in this study. There were 34 patients in NTLJDK group (TLJA <10°) and 43 patients in TLJDK group (TLJA ≥10°). The median angle of lumbar lordosis (LL) in the NTLJDK or TLJDK groups was 23.40° (18.50°, 29.48°) or 19.50° (13.30°, 24.55°), respectively. The median TLJAs in all patients and both groups were -11.20° (-14.60°, -4.80°), -3.70° (-7.53°, -1.73°), and -14.30° (-17.45°, -13.00°), respectively. In the NTLJDK group, LL was correlated with thoracic kyphosis (TK; r = -0.400, P = 0.019), sacral slope (SS; r = 0.681, P < 0.001), and C7-sagittal vertical axis (r = -0.402, P = 0.018). In the TLJDK group, LL was correlated with TK (r = -0.345, P = 0.024), SS (r = 0.595, P < 0.001), and pelvic tilt (r = -0.363, P = 0.017). There were significant differences in LL, TLJA, TK, SS, and pelvic incidence (PI) between two groups. CONCLUSIONS: Although TLJDK is common in patients with lumbar degenerative kyphosis, it might be generated by special characteristics of morphology and biomechanics of the TLJ. To maintain sagittal balance, pelvis back tilt might be more important in patients with TLJDK, whereas thoracic curve changes might be more important in patients without TLJDK.

[Efficacy of delayed administration of etanercept after spinal cord injury].

OBJECTIVE: To observe the effect of delayed administration of etanercept on the motor function, the expression of apoptosis-related genes and the pathological alterations of spinal cord in vivo in experimental murine model of spinal cord injury (SCI). METHODS: Seventy-two male adult SD rats were randomly divided into 6 groups, which were subjected to SCI induced by the application of vascular clips (force of 70 g) to the dura. Experimental groups (E1, E2, and E3 group) were given administration of etanercept immediately, 1 h, and 8 h after SCI. The control groups (C1, C2, and C3 group) were given administration of saline at the same time as experimental groups. Six rats of each group were killed 24 h after SCI in order to collect the samples for testing the expression of Bax and Bcl-2 by Western blot. The rest were killed 14 d after SCI for observing the pathological alteration using light microscopy. The recovery of motor function was graded using the modified murine Basso, Beattle, and Bresnahan (BBB). RESULTS: (1) The results of the expressions of Bax and Bcl-2 by Western blot: the gray value of the expression of Bax of E1 group was 165.423 ± 2.946, of E2 group 135.391 ± 3.045, of E3 group 108.543 ± 6.999, and of the control group 69.054 ± 0.774, and the gray value of the expression of Bcl-2 of E1 group was 58.854 ± 3.592, of E2 group 84.315 ± 2.138, of E3 group 125.091 ± 2.699, and of the control group 156.304 ± 2.490. (2) The results of BBB score: etanercept given immediately or 1 h after SCI could improve the recovery of the rats. There were significant differences in BBB score 14 d after SCI between E1 group (13.000 ± 1.095) and C1 group (7.167±0.753), E2 group (9.833 ± 1.472) and C2 group (7.000 ± 0.632) while there were no significant difference between E3 group (7.333 ± 0.516) and C3 group (6.833±0.753). (3) The result of histological alteration: histological alterations, such as necrosis, infiltration of lymphocytes and fibroblast and loss of nerve cells, were found attenuated in E1 and E2 groups, compared with C1 and C2 groups. There was no obvious difference between E3 and C3 groups. CONCLUSION: Administration of etanercept may inhibit the apoptosis after SCI, but this kind of effect may be too weak to improve the BBB score and histological alterations obviously when administration of etanercept is delayed 8 h after SCI. The clinical value of etanercept to SCI needs to be further validated.

[Finite element analysis of lumbar fusion and Topping-off surgery].

OBJECTIVE: To evaluate the effect of Topping-off surgery on the adjacent segment of PLIF. METHODS: A finite element model of the human lumbar spine (L1-L5) was developed. The intact spinal model was validated by comparing it with previously reported models. Then, 2 models were analyzed and compared: (1) posterior lumbar interbody fusion (PLIF) at L4/5; (2) posterior lumbar interbody fusion at L4/5 and implantation of the interspinous spacer (ISP) at L3/4 (Topping-off). Then 500 N compressive loading plus 10 Nm moments simulating flexion, extension, lateral bending and axial rotation were imposed on both the L1 superior endplates. The ranges of motion, intradiscal pressures, facet stresses in L3/4, the stresses on spinous processes in L3 and L4 were investigated. All the measured data were analyzed by SPSS 21.0. RESULTS: The effect of the Topping-off on the adjacent segment appeared mainly in flexion-extension: the ranges of motion, intradiscal pressures (annulus and nucleus pulposus), both facet stresses were lower than that of the PLIF model, and the stresses on spinous processes in L3 and L4 were larger. Besides, the facet stresses on the left side in the left lateral bending were also lower than those of the PLIF model. CONCLUSION: Topping-off model is able to restrict the range of motion of the lumbar adjacent segment, decrease the intradiscal pressure and facet stresses, and has a potential effect of preventing adjacent segmental degeneration.

[Effects of intrathecal injection of methylprednisolone sodium succinate in acute spinal cord injury rabbits].

OBJECTIVE: To investigate the effects and apoptosis of intrathecal injection of Methylprednisolone Sodium Succinate (MPss) for acute spinal cord injury (SCI) in New Zealand rabbits. METHODS: Seventy-two healthy New Zealand rabbits were used for the procedure and were randomly divided into two groups: SCI group and SHAM group, which was both divided into 6 subgroups, such as the vehicle group, the MPss intrathecal injection groups (1.5 mg/kg, 3.0 mg/kg, 6.0 mg/kg group), the MPss intravenous injection group and the combined injection group. TARLOV score was tested daily to evaluate the motor function. The rabbits were sacrificed 7 days after the surgery and the thoracic spinal cord sections and the sacral sections where MPss was injected were harvested for HE and TUNEL staining. Two-Factors Repeated Measures analysis of variance for TARLOV scores tested at various times and One-Way ANOVA analysis of variance for data between groups were used. RESULT: Seven days after surgery in SCI group, there was no statistical difference between the TARLOV scores of intrathecal injection of MPss 3.0 mg/kg group, 6.0 mg/kg group and MPss intravenous injection group (P > 0.05), which were all better than the vehicle group (F = 4.762, P < 0.05). Referring to the lymphocyte infiltration at the injury site in SCI group, there was statistical difference between MPss intrathecal injection 6.0 mg/kg group (1.33 ± 0.21) and the vehicle group (2.67 ± 0.21) (F = 5.793, P < 0.05) and no statistical difference between intrathecal injection of MPss 6.0 mg/kg group and MPss intravenous injection group (P > 0.05). As for the lymphocyte infiltration at the intrathecal injection site in SHAM group, there was statistical difference between MPss intrathecal injection 6.0 mg/kg group (2.50 ± 0.55) and the vehicle group (0.50 ± 0.55) (F = 17.333, P < 0.05). TUNEL staining in SCI group showed statistical difference between MPss intrathecal injection 6.0 mg/kg group (6.3 ± 1.5) and the vehicle group (20.3 ± 2.2) (F = 71.279, P < 0.05). CONCLUSIONS: Intrathecal injection of MPss can improve the functional recovery of lower limb and decrease apoptosis of neuron cells,which can provide same effects as the traditional intravenous injection of MPss in New Zealand rabbits.

[Long-term clinical outcomes of selective segmental transforaminal lumbar interbody fusion and posterior spinal fusion for degenerative lumbar scoliosis].

OBJECTIVE: To explore the surgical techniques and long-term clinical outcomes of degenerative scoliosis (DS) with selective segmental transforaminal lumbar interbody fusion (TLIF) and posterior spinal fusion. METHODS: Ninety-five patients with adult degenerative lumbar scoliosis undergoing posterior long fusion at our department from January 1999 to December 2007 were analyzed retrospectively. The average follow-up period was 7.8 (5-13) years. The clinical outcomes of Oswestry disability index (ODI), visual analog scale (VAS), patient satisfaction and such radiographic parameters as Cobb angle, apical vertebra translation (AVT), Nash-Moe grade, lumbar lordosis (LL) and thoracolumbar kyphosis (TLK) were evaluated. RESULTS: The clinical outcomes of ODI score and VAS significantly improved at the last visit (P < 0.05). The ODI score was 32.2 ± 8.6 before surgery and 11.1 ± 6.8 at the last visit. The VAS was 8.9 ± 2.0 before surgery and 2.0 ± 1.2 at the last visit. Patient satisfaction was 88.2% (84/95) at the last visit. At the final evaluation, Cobb's angle, apical vertebra translation and Nash-Moe grades decreased with a statistically significant difference (P < 0.001) compared with preoperative parameters.Lordotic angle had a significant increase than preoperative angle (P < 0.001). Thoracolumbar kyphosis showed no significant change (P > 0.05). Besides, a significant positive correlation existed between the decrease of ODI score and the increment of lumbar lordotic angle (r = 0.62, P = 0.01) .Long-term complications included broken rod (n = 2), coronal junctional scoliosis (n = 4), L5-S1 spondylolisthesis (n = 2), L5-S1 restenosis (n = 5). And 11 patients underwent reoperation. CONCLUSION: A combination of selective segmental TLIF and posterior spinal fusion is both safe and effective for degenerative scoliosis and excellent long-term clinical outcomes may be achieved. And selective segmental TLIF can facilitate solid fusion, improvement of lumbar lordosis, better correction of lateral spondylolisthesis and asymmetric disc space so as to yield better corrective effects and long-term clinical outcomes.

[The efficacy and complication analysis of interspinous dynamic device (Wallis) in patients of degenerative lumbar disease].

OBJECTIVES: To review degenerative lumbar disease treated with Wallis and the re-herniation cases after the implantation of Wallis, so as to evaluate the effect of the device. METHODS: From January 2009 to June 2010, a retrospective analysis was done and 48 patients (30 males and 18 females) with an average age of 43 years (ranging from 17 to 69 years), who received stabilization of the segment using the Wallis device, were reviewed. The involved segments included: 4 cases at L(3-4), 38 cases at L(4-5), 6 cases at L(5)-S(1). Preoperative and postoperative visual analogue scales (VAS) and Oswestry disability index (ODI) were recorded to evaluate the clinical efficiency, imageology diversity was assessed by X-rays and MRI. RESULTS: All cases received fenestration and the implantation of Wallis. No surgery related complications were recorded. There were 48 cases were followed up. The average follow-up period was (20 ± 4) months (12 - 30 months). The average ODI score dropped from 46 ± 10 to 24 ± 7 (t = 12.765, P < 0.05). The average VAS for back and leg pain dropped from 8.1 ± 1.6 to 2.1 ± 1.1(t = 21.881, P < 0.05). Six patients with recurrent lower back and leg pain were diagnosed by MRI, as recurrent herniation (6/48, 12.5%). All re-herniation occurred at L(4-5) level, between 2 and 13 months after the surgery. Three of the 6 patients underwent additional discectomy and fusion, others received conservative treatment. CONCLUSIONS: Although existing problems such as recurrence after surgery, the clinical outcome of Wallis in treating protrusion of lumbar intervertebral disc and lumbar stenosis is satisfied in middle-early stage.

Comparison of Topping-off and posterior lumbar interbody fusion surgery in lumbar degenerative disease: a retrospective study.

BACKGROUND: Topping-off surgery is a newly-developed surgical technique which combines rigid fusion with an interspinous process device in the adjacent segment to prevent adjacent segment degeneration. There are few reports on Topping-off surgery and its rationality and indications remains highly controversial. Our study aims to investigate the short-term and mid-term clinical results of Topping-off surgery in preventing adjacent segment degeneration when mild or moderate adjacent segment degeneration existed before surgery. METHODS: The 25 cases that underwent L5-S1 posterior lumbar interbody fusion (PLIF) + L4-L5 interspinous process surgeries between April 2008 and March 2010 formed Topping-off group. The 42 cases undergoing L5-S1 PLIF surgery formed PLIF group. Both groups matched in gender, age, body mass index and Pfirrmann grading (4 to 6). The patients were evaluated with visual analogue scale (VAS) and Japanese orthopaedic association (JOA) scores before surgery and in the last follow-up. Modic changes of endplates were recorded. RESULTS: The follow-up averaged 24.8 and 23.7 months. No symptomatic or radiological adjacent segment degeneration was observed. There was no significant difference in intraoperative blood loss or postoperative drainage. VAS and lumbar JOA scores improved significantly in both groups (t = 12.1 and 13.5, P < 0.05). Neither anterior nor posterior disc height was significantly changed. Segmental lordosis of L4-L5 and total lordosis were all increased significantly (Topping-off group: t = -2.30 and -2.24,P < 0.05; PLIF group: t = -2.76 and -1.83, P < 0.01). In the hyperextension and hyperflexion view, Topping-off group's range of motion (ROM) and olisthesis in the L4-L5 segment did not significantly change in flexion, but decreased in extension. In PLIF group, ROM (t = -7.82 and -4.90, P < 0.01) and olisthesis (t = -15.67 and -18.58, P < 0.01) both significantly increased in extension and flexion. CONCLUSIONS: Compared with single segment PLIF surgery, Topping-off surgery can achieve similar symptomatic improvement in cases with pre-existing mild or moderate adjacent segment degeneration, restrict the adjacent segment's ROM in extension and prevent excessive olisthesis of adjacent segment in both extension and flexion.

[Clinical outcomes of Hybrid-surgery to treat the two-level cervical disease].

OBJECTIVE: To evaluate the clinical and radiologic outcomes of the Hybrid surgery (cervical artificial disc replacement combined with anterior cervical discectomy and fusion (ACDF)) and the effective of the adjacent segment. METHODS: Between December 2007 to June 2010, 34 patients underwent 2-level cervical disc surgery. There were 17 patients underwent Hybrid surgery (Hybrid group), 17 patients underwent 2-level ACDF (ACDF group). Japanese orthopaedic association (JOA), neck disability index (NDI), and Odom's standards were evaluated. Dynamic flexion and extension lateral cervical radiographs were obtained in the standing position before surgery and at routine postoperative intervals of 1, 3, 6 months. RESULTS: Both of the two groups had significantly improvement than preoperative in JOA (t = -8.790 - -5.803, P < 0.05) and NDI scores (t = 10.717 - 13.514, P < 0.05), but no significantly difference between the two groups (P > 0.05). Both of the two groups had significantly decreased in the mean C(2-7) range of motion (ROM). The Hybrid group decreased from 46° ± 11° preoperative to 41° ± 8° at the 6 mouths after surgery (t = 3.170, P < 0.05). The ACDF group decreased from 45° ± 13° preoperative to 38° ± 15° at the 6 mouths after surgery (t = 6.709, P < 0.05). But there were no significantly difference between the two groups (P > 0.05). In the Hybrid group, both the superior adjacent segment ROM and the inferior adjacent segment ROM were decreased in the follow-up, there had significantly difference at the 1 and 3 months after surgery (superior adjacent segment: t = 5.622 and 4.032, P < 0.05; inferior adjacent segment: t = 2.879 and 2.207, P < 0.05), but no significantly difference after 6 months (P > 0.05). In the ACDF group, the ROM of the inferior adjacent segment was significantly increased at 3 and 6 months after surgery (t = -7.038 and -13.540, P < 0.05), the ROM of the superior adjacent segment was significantly increased at 6 months after surgery (t = -2.453, P < 0.05). CONCLUSIONS: Hybrid surgery has excellent clinical results and decreases the ROM of the adjacent segment in the following 6 months, meanwhile 2-level ACDF increases the ROM of the adjacent segment. The long-term clinical outcomes of the Hybrid surgery need more study.

[The effect of Topping-off surgery on preventing adjacent segment degeneration, a retrospective study].

OBJECTIVE: To investigate the early-middle stage clinical results of Topping-off surgery in preventing adjacent segment degeneration when mild or moderate adjacent segment degeneration exists before surgery. METHODS: All the cases that received L(5)-S(1) posterior lumbar interbody fusion (PLIF)+L(4)-L(5) interspinous process (ISP) surgeries between April 2008 and March 2010 (Topping-off group) were analyzed retrospectively. The cases received L(5)-S(1) PLIF surgery and whose intervertebral disc degeneration using modified Pfirrmann's grading system were grade 4 - 6 were analyzed retrospectively at the same time (PLIF group). Both groups matched in gender, age, body mass index and Pfirrmann's grading of disc. All the patients were evaluated with visual analogue scale (VAS) and Japanese orthopaedic association (JOA) scores before the surgery and in the last follow-up. The X-ray films before and after surgery were measured. RESULTS: There were 25 patients in Topping-off group and 42 patients in PLIF group were included in the final analysis. The follow-up averaged 24.8 and 23.7 months. No symptomatic or radiological adjacent segment degeneration was observed. The average surgery time was (120 ± 24) min and (106 ± 21) min. There was no significant difference in the blood loss during surgery or post-operation drainage (P > 0.05). VAS and lumbar JOA score improved in both groups (P < 0.01). In the lateral view of lumbar spine, neither of anterior or posterior disk height was significantly changed (P > 0.05), segmental lordosis of L(4)-L(5), total lordosis were all increased (Topping-off group: t = -2.30 and -2.24, P < 0.05; PLIF group: t = -2.76 and -1.83, P < 0.05). In the hyperextension and hyperflexion view, Topping-off group's range of motion (ROM) and olisthesis in the L(4-5) segment did not significantly change in flexion (P > 0.05), but decreased in extension (t = 5.83 and 4.92, P < 0.01). In PLIF group, the ROM (t = -7.82 and -4.90, P < 0.01) and olisthesis (t = -15.67 and -18.58, P < 0.01) both significantly increased in extension and flection. CONCLUSIONS: Compared with single segmental PLIF surgery, Topping-off surgery can achieve similar symptomatic improvement in cases with pre-existing mild or moderate adjacent segment degeneration, restrict the adjacent segment's range of motion in extension and prevent excessive olisthesis of adjacent segment in both extension and flexion. Topping-off surgery has a potential effect of preventing adjacent segmental degeneration.

[Comparison of allogenic versus ostetic artificial bone in double door laminoplasty].

OBJECTIVE: To study the application of allogenic bone and Ostetic artificial bone in double door laminoplasty. METHODS: From June 2004 to June 2010, a total of 111 patients underwent double door laminoplasty. And allogenic (group A, n = 63) and Ostetic artificial (group B, n = 48) bones were used. They had spinal stenosis at least several levels or OPLL (Ossification of posterior longitudinal ligament). Their follow-up period was 12 months. Anteroposterior compression ratio was used to evaluate the neurological status. Range-of-movement (ROM) of cervical spine and bone fusion was determined by radiography and computed tomography (CT) during the follow-ups. RESULTS: Anteroposterior compression ratio: group A improved from 0.18 preoperation to 0.43 postoperation while group B increased from 0.20 preoperation to 0.44 postoperation; ROM: group A decreased postoperatively to (22.6 ± 3.3)° from (39.5 ± 6.1)° while group B decreased postoperatively to (22.9 ± 3.7)° from (39.3 ± 6.7)°. When Groups A and B were compared, bone fusion between allograft and spinous processes was completed in 73.1% vs 64.2%, partial fusion in 22.4% vs 18.7% and failed in 6.3% vs 17.1%. CONCLUSION: Uses allogenic and Ostetic artificial bones in double door laminoplasty may achieve an excellent decompression of spinal cord. But the application of allogenic bone yields a higher bone fusion rate after surgery.

[Experimental correlation study of lumbar spinal stenosis and knee joint degeneration].

OBJECTIVE: To explore the correlation of lumbar stenosis and knee osteoarthritis by establishing a rabbit lumbar spinal stenosis model and observing the hind limb movement function and pathological change of articular cartilage of knee joint. METHODS: A total of 36 healthy adult rabbits were randomly divided into model group and control group. In the model group, spinal canal was filled with bone pieces to make lumbar spinal stenosis; in the control group, sham operation was performed and materials were inserted into spinal canal. Movement function was evaluated by Tarlov method and pathological features were observed by Mankin's scores under light microscope at 4, 8 and 12 weeks. RESULTS: Early degenerative changes of knee cartilage were observed in the model group at 4 and 8 weeks post-operation. There were synovial hyperemia and hyperplasia, increased synovial fluid effusion and lightly-stained cartilage. The Mankin score was 3.3 - 4.5 and Tarlov score 3 - 4. Intermediate stage changes of osteoarthritis were found in the model group at 12 weeks post-operation, showing synovial hyperplasia, decreased synovial fluid, fissure in cartilage surface, tangled cartilage cells and unevenly stained matrix. The Mankins score was 7 - 9 and Tarlov score 2 - 3. Most of articular cartilage was normal in the control group with Mankin score of 0 - 1 and Tarlov score of 4. CONCLUSION: Lumbar stenosis may be correlated with knee joint degeneration.

[Surgical treatment of multilevel lumbar degenerative spondylolisthesis].

OBJECTIVE: To discuss the surgical treatment of multilevel lumbar degenerative spondylolisthesis. METHODS: From March 2005 to September 2008, 25 cases of multilevel lumbar degenerative spondylolisthesis were treated with total laminectomy, reduction of spondylolisthesis and 360 degrees circumferential fusion through interbody (PLIF), transverse process (PLF) and pedicle screw fixation. All cases were followed up for 0.5 - 4 years. The Lenke grading system was used to assess the spinal fusion and Henderson grading system was used to assess the clinical outcomes. RESULTS: Complete reduction of spondylolisthesis was achieved in all cases. The bone fusion was grade A in 23 cases, grade B in 2 cases. The clinical outcome was excellent in 16 cases, good in 6 cases and poor in 3 cases. CONCLUSIONS: The pathogenesis of lumbar degenerative multilevel spondylolisthesis is different from that of single-level spondylolisthesis. Complete decompression, reduction of spondylolisthesis sufficient fusion and reliable pedicle screw fixation can provide successful interbody fusion and satisfactory clinical results.It's crucial to reduce multilevel spondylolisthesis by proper techniques based on different types of listhesis.