Unveiling heterogeneity in MSCs: exploring marker-based strategies for defining MSC subpopulations.

Mesenchymal stem/stromal cells (MSCs) represent a heterogeneous cell population distributed throughout various tissues, demonstrating remarkable adaptability to microenvironmental cues and holding immense promise for disease treatment. However, the inherent diversity within MSCs often leads to variability in therapeutic outcomes, posing challenges for clinical applications. To address this heterogeneity, purification of MSC subpopulations through marker-based isolation has emerged as a promising approach to ensure consistent therapeutic efficacy. In this review, we discussed the reported markers of MSCs, encompassing those developed through candidate marker strategies and high-throughput approaches, with the aim of explore viable strategies for addressing the heterogeneity of MSCs and illuminate prospective research directions in this field.

Improved therapeutic consistency and efficacy of CD317+ MSCs through stabilizing TSG6 by PTX3.

BACKGROUND: Previously, we have demonstrated that the batch variations of human platelet lysate (conventional MSC expansion medium) induce MSC heterogeneity and therapeutic inconsistency. On the other hand, the MSCs expanded with chemical defined medium have improved therapeutic consistency. METHODS: In the current study, we studied the MSC subpopulation composition and variation in different types and batches of MSC expansion medium with scRNA-seq analysis. RESULTS: MSCs expanded with different batches of media have higher levels of heterogeneity from the perspective of cell subpopulation composition at transcriptome levels and therapeutic inconsistency. The CD317+ subpopulation has enhanced immune suppression activities. And the percentage of CD317+ MSCs within MSCs is tightly correlated with its immune suppression activities, and also contributes to the heterogeneity and therapeutic inconsistency of MSCs. the CD317+ MSCs have increased expression levels of PTX3, which might stabilize the TSG6 protein and improve the therapeutic effects CONCLUSIONS: Thus, purifying CD317+ MSCs is one efficient strategy to reduce MSC heterogeneity and increase the therapeutic consistency of MSCs.

CD317+ MSCs expanded with chemically defined media have enhanced immunological anti-inflammatory activities.

BACKGROUND: Although both preclinical and clinical studies have shown the great application potential of MSCs (mesenchymal stem/stromal cells) in treating many kinds of diseases, therapeutic inconsistency resulting from cell heterogeneity is the major stumbling block to their clinical applications. Cell population diversity and batch variation in the cell expansion medium are two major inducers of MSC heterogeneity. METHODS: Cell population diversity was investigated through single-cell RNA sequencing analysis of human MSCs derived from the umbilical cord and expanded with fully chemically defined medium in the current study. Then, the MSC subpopulation with enhanced anti-inflammatory effects was studied in vitro and in vivo. RESULTS: Our data showed that MSCs contain different populations with different functions, including subpopulations with enhanced functions of exosome secretion, extracellular matrix modification and responses to stimuli (regeneration and immune response). Among them, CD317+ MSCs have improved differentiation capabilities and enhanced immune suppression activities. Underlying mechanism studies showed that higher levels of TSG6 confer enhanced anti-inflammatory functions of CD317+ MSCs. CONCLUSIONS: Thus, CD317+ MSCs might be a promising candidate for treating immunological disorder-related diseases.

Coordination of Axial Trunk Rotations During Gait in Low Back Pain. A Narrative Review.

Chronic low back pain patients have been observed to show a reduced shift of thorax-pelvis relative phase towards out-of-phase movement with increasing speed compared to healthy controls. Here, we review the literature on this phase shift in patients with low back pain and we analyze the results presented in literature in view of the theoretical motivations to assess this phenomenon. Initially, based on the dynamical systems approach to movement coordination, the shift in thorax-pelvis relative phase with speed was studied as a self-organizing transition. However, the phase shift is gradual, which does not match a self-organizing transition. Subsequent emphasis in the literature therefore shifted to a motivation based on biomechanics. The change in relative phase with low back pain was specifically linked to expected changes in trunk stiffness due to 'guarded behavior'. We found that thorax-pelvis relative phase is affected by several interacting factors, including active drive of thorax rotation through trunk muscle activity, stride frequency and the magnitude of pelvis rotations. Large pelvis rotations and high stride frequency observed in low back pain patients may contribute to the difference between patients and controls. This makes thorax-pelvis relative phase a poor proxy of trunk stiffness. In conclusion, thorax-pelvis relative phase cannot be considered as a collective variable reflecting the orderly behaviour of a complex underlying system, nor is it a marker of specific changes in trunk biomechanics. The fact that it is affected by multiple factors may explain the considerable between-subject variance of this measure in low back pain patients and healthy controls alike.

Early results of thoraco lumbar burst fracture treatment using selective corpectomy and rectangular cage reconstruction.

BACKGROUND: Subsidence and late fusion are commonly observed in anterior subtotal corpectomy and reconstruction for treating thoracolumbar burst fractures. The subsidence rate of this surgical method was reported from 19.6% to 75% in the literatures, which would cause treatment failure. Thus, an improvement of anterior surgery technique should be studied to reduce these complications. MATERIALS AND METHODS: 130 patients of thoracolumbar burst fractures treated by minimal corpectomy, decompression and U cage, between January 2009 and December 2010 were included in this study. The hospital Ethical Committee approved the protocols. The American Spinal Injury Association (ASIA) scale, visual analog scales, and Oswestry Disability Index (ODI) scores were used for clinical evaluation. The local kyphosis angle, vertebral height (one level above the fractured vertebral to one level below), canal stenosis, and fusion status were used to assess radiological outcome. All complications and demographic data such as number of male/female patients, average age, mode of trauma, burst level involved, mean surgery time and blood lost were reported. RESULTS: 120 patients were followed up for 24 months. Most patients had improvement of at least 1 ASIA grade, and all experienced pain reduction. The mean ODI score steadily decreased after the surgery (P < 0.01). Approximately, 83.3% of patients achieved solid fusion at 3 months and reached 98.3% at 6 months. The kyphosis angle and radiographic height were corrected significantly after the surgery and with a nonsignificant loss of correction at 24 months (P > 0.05). The average canal stenosis index was increased from 39% to 99% after surgery. No cage subsidence or implant failure was observed. CONCLUSIONS: The clinical outcomes described here suggest that the selective corpectomy and rectangular cage reconstruction can effectively promote solid fusion and eliminate complications related to subsidence or implant failure.

Cementless arthroplasty with a distal femoral shortening for the treatment of Crowe type IV developmental hip dysplasia.

BACKGROUND: Severe developmental dysplasia of the hip is a surgical challenge. The purpose of this study is to describe the cementless arthroplasty with a distal femoral shortening osteotomy for Crowe type IV developmental hip dysplasia and to report the results of this technique. MATERIALS AND METHODS: 12 patients (2 male and 10 female) of Crowe type IV developmental hip dysplasia operated between January 2005 and December 2010 were included in the study. All had undergone cementless arthroplasty with a distal femoral shortening osteotomy. Acetabular cup was placed at the level of the anatomical position in all the hips. The clinical outcomes were assessed and radiographs were reviewed to evaluate treatment effects. RESULTS: The mean followup for the 12 hips was 52 months (range 36-82 months). The mean Harris hip score improved from 41 points (range 28-54) preoperatively to 85 points (range 79-92) at the final followup. The mean length of bone removed was 30 mm (range 25-40 mm). All the osteotomies healed in a mean time of 13 weeks (range 10-16 weeks). There were no neurovascular injuries, pulmonary embolism or no infections. CONCLUSION: Our study suggests that cementless arthroplasty with a distal femoral shortening is a safe and effective procedure for severe developmental dysplasia of the hip.

Frontal plane kinematics in walking with moderate hip osteoarthritis: Stability and fall risk.

BACKGROUND: Hip abductor weakness and unilateral pain in patients with moderate hip osteoarthritis may induce changes in frontal plane kinematics during walking that could affect stability and fall risk. METHODS: In 12 fall-prone patients with moderate hip osteoarthritis, 12 healthy peers, and 12 young controls, we assessed the number of falls in the preceding year, hip abductor strength, fear of falling, Harris Hip Score, and pain. Subjects walked on a treadmill with increasing speeds, and kinematics were measured opto-electronically. Parameters reflecting gait stability and regressions of frontal plane center of mass movements on foot placement were calculated. We analyzed the effects of, and interactions with group, and regression of all variables on number of falls. FINDINGS: Patients walked with quicker and wider steps, stood shorter on their affected leg, and had larger peak speeds of frontal plane movements of the center of mass, especially toward their unaffected side. Patients' static margins of stability were larger, but the unaffected dynamic margin of stability was similar between groups. Frontal plane position and acceleration of the center of mass predicted subsequent step width. The peak speed of frontal plane movements toward unaffected had 55% common variance with number of falls, and adding the Harris Hip Score into bivariate regression led to 83% "explained" variance. INTERPRETATION: Quickening and widening steps probably increase stability. Shorter affected side stance time to avoid pain, and/or weakened affected side hip abductors, may lead to faster frontal plane trunk movements toward the unaffected side, which could contribute to fall risk.

Low dose of glucocorticoid decreases the incidence of complications in severely burned patients by attenuating systemic inflammation.

BACKGROUND: Excessive systemic inflammatory response remains as a major problem underlying severe burns. This study aimed to assess the effect of low-dose glucocorticoid treatment in downregulating systemic inflammation in severely burned patients. METHODS: A prospective study from 2001 to 2014 at our hospital was conducted to compare the patients who received low-dose glucocorticoid during the acute phase with those who did not. Patients with burns 70% or greater of their total body surface area were included, and their plasma levels of inflammatory cytokines and clinical outcomes were compared. RESULTS: A total of 69 patients were included in this study, with 31 patients receiving glucocorticoid treatment and the others not. Patient demographics including age, burn size, and incidence of inhalation injury were similar in both groups. The incidence of pulmonary infection and stress ulcer (and/or hemorrhage) was 24.2% and 3.0% in the treatment group, respectively, significantly lower than 47.8% and 19.6% of the control group (P < .05). Length of hospital stay was almost 13 days shorter in the treatment group (P < .05), whereas there was no significant difference in the overall mortality, duration of mechanical ventilation, and incidence of sepsis between the 2 groups. The enzyme-linked immunosorbent assay results confirmed that the plasma levels of C-reactive protein, tumor necrosis factor-α, interleukin-6, and interleukin-8 were significantly lower in the treatment group (P < .05). CONCLUSION: Low dose of glucocorticoid treatment during the acute phase could reduce the levels of proinflammatory cytokines in severely burned patients and subsequently decrease the incidence of pulmonary infection and stress ulcer, as well as the length of hospital stay.

[EFFECTS OF ANTERIOR SINGLE SEGMENT FIXATION ON SPINAL STABILITY IN TREATMENT OF THORACOLUMBAR BURST FRACTURE OF Denis TYPE B WITH PEDICLE INJURY].

OBJECTIVE: To investigate the effects of anterior single segment fixation on the spinal biomechanical stabilization in the treatment of thoracolumbar burst fracture of Denis type B with pedicle injury. METHODS: Six fresh human cadaveric spine specimens (T11-L3) were harvested as normal control (group A). Then the L1 Denis type B fracture model was created by the hemi-corpectomy method. Each specimen was tested in 3 different scenarios: anterior single segment (T12, L1) fixation with the integrity of the pedicle (group B), anterior single segment fixation with the resection of the unilateral pedicle (group C), and anterior single segment fixation with the resection of the bilateral pedicles (group D). Range of motion (ROM) in flexion/extension, bilateral bending, and bilateral axial rotation was measured by spinal three-dimensional measuring system under pure moments of 8.0 N x m. RESULTS: The ROM values of T12, L1 in flexion, extension, and right/left lateral bending of groups B, C, and D were significantly lower than those of group A (P < 0.05); group D was significantly higher than groups B and C (P < 0.05); but groups B and C showed no significant difference (P > 0.05). The ROM values of T12, L1 in right/left axial rotation of groups B and C were significantly lower than those of groups A and D (P < 0.05), but there was no significant difference (P > 0.05) between groups B and C and between groups A and D. The ROM values of L1,2 in flexion, extension, right/left lateral bending, and right/left axial rotation showed no significant difference between groups (P > 0.05). CONCLUSION: Resection of the unilateral pedicle has litter effects on the spine biomechanical stabilization of the anterior single segment fixation in the 6 degrees of freedom. However, the bilateral resection results show significant decrease in flexion, extension, lateral bending, and rotation motion stability by the single segment fixation devices, especially in the axial rotation aspect.

Polymer-free patterning of graphene at sub-10-nm scale by low-energy repetitive electron beam.

A polymer-free technique for generating nanopatterns on both synthesized and exfoliated graphene sheets is proposed and demonstrated. A low-energy (5-30 keV) scanning electron beam with variable repetition rates is used to etch suspended and unsuspended graphene sheets on designed locations. The patterning mechanisms involve a defect-induced knockout process in the initial etching stage and a heat-induced curling process in a later stage. Rough pattern edges appear due to inevitable stochastic knockout of carbon atoms or graphene structure imperfection and can be smoothed by thermal annealing. By using this technique, the minimum feature sizes achieved are about 5 nm for suspended and 7 nm for unsuspended graphene. This study demonstrates a polymer-free direct nanopatterning approach for graphene.

Combination of a fast cleanup procedure and a DR-CALUX® bioassay for dioxin surveillance in Taiwanese soils.

Our goal was to determine dioxin levels in 800 soil samples collected from Taiwan. An in vitro DR-CALUX® assay was carried out with the help of an automated Soxhlet system and fast cleanup column. The mean dioxin level of 800 soil samples was 36.0 pg-bioanalytical equivalents (BEQs)/g dry weight (d.w.). Soil dioxin-BEQs were higher in northern Taiwan (61.8 pg-BEQ/g d.w.) than in central, southern, and eastern Taiwan (22.2, 24.9, and 7.80 pg-BEQ/g d.w., respectively). Analysis of multiple linear regression models identified four major predictors of dioxin-BEQs including soil sampling location (ß = 0.097, p < 0.001), land use (ß = 0.065, p < 0.001), soil brightness (ß = 0.170, p < 0.001), and soil moisture (ß = 0.051, p = 0.020), with adjusted R2 = 0.947 (p < 0.001) (n = 662). An univariate logistic regression analysis with the cut-off point of 33.4 pg-BEQ/g d.w. showed significant odds ratios (ORs) for soil sampling location (OR = 2.43, p < 0.001), land use (OR = 1.47, p < 0.001), and soil brightness (OR = 2.83, p = 0.009). In conclusion, four variables, including soil sampling location, land use, soil brightness, and soil moisture, may be related to soil-dioxin contamination. Soil samples collected in northern Taiwan, and especially in Bade City, soils near industrial areas, and soils with darker color may contain higher dioxin-BEQ levels.

Artificial disk replacement combined with midlevel ACDF versus multilevel fusion for cervical disk disease involving 3 levels.

The optimal surgical approach for cervical disk disease remains a matter of debate, especially for multilevel disease. The purpose of this study was to compare the results of 2 surgical strategies for cervical disk disease involving 3 levels: hybrid constructs, artificial disk replacement combined with midlevel anterior cervical diskectomy and fusion (ACDF), and 3-level ACDF. The authors prospectively compared patients who had cervical disk disease involving 3 levels that was treated with hybrid constructs or with 3-level ACDF. Patients were asked to use the Neck Disability Index (NDI) to grade their pain intensity preoperatively and at routine postoperative intervals of 1, 3, 6, 12, and 24 months. Dynamic flexion and extension lateral cervical radiographs were obtained while in the standing position preoperatively and at the postoperative intervals. The angular range of motion for C2-C7 and the adjacent segments was measured using the Cobb method. Twenty-four patients were treated, 12 with hybrid constructs and 12 with 3-level ACDF. Both groups had significant postoperative improvement in NDI scores and neck pain (P<.05). However, no significant difference was found between the groups (P>.05). The hybrid constructs group showed faster recovery of C2-C7 range of motion. Mean C2-C7 range of motion of the hybrid constructs group recovered to that of the preoperative value, but that of the 3-level ACDF group did not (P<.05). Range of motion of the superior and inferior adjacent segments showed significant differences between the 2 groups at 12 and 24 months postoperatively (P<.05). These findings suggest that the hybrid constructs is a safe and effective alternative for cervical disk disease involving 3 levels. The definite stabilization and maintained range of motion can be achieved right away, which can ensure a good preliminary clinical outcome.

Design and biomechanical properties of a new reconstruction device for treating thoracolumbar burst fractures.

Implants currently used for reconstruction of a burst vertebral body are associated with complications, including subsidence, nonunion, and substantial intraoperative blood loss. A new reconstruction device, the U-Cage (Double Engine Medical Material Ltd, Xiamen, Fujian, China), was designed to minimize complications.Six intact adult cadaver thoracolumbar (T11-L3) spines were collected and scanned by dual-energy X-ray absorptiometry (DEXA). The stiffness of the burst spine was subsequently compared with its previous intact state during flexion/extension, lateral bending, and rotation, and then subjected to a cyclic test to predict cage subsidence and device loosening. Axial load was applied continuously until failure to test the peak load that the specimen could withstand during the cyclic test. The correlation of bone mineral density and peak load was also analyzed. The instrumented specimens were found to be equivalent to intact bone in all directions (P>.05), with the exception of left rotation (P<.05). All specimens could withstand the cyclic test, and no subsidence or loosening of the device was detected. Average peak load for the instrumented specimens was 4137.5 N, which correlated with the average bone mineral density (r=0.915; P=.011).Thoracolumbar burst fractures instrumented with a U-Cage and anterolateral D-rod fixation achieved a stiffness similar to that of intact spines. This procedure may avoid the subsidence of the cage in vivo and serve as a better option for treating thoracolumbar burst fractures.

[Comparison of three methods of internal fixations for intertrochanteric femoral fractures in elderly patients].

OBJECTIVE: To compare the clinical effects of three methods of internal fixations in treating intertrochanteric fractures in elderly patients. METHODS: From 2004 to 2008, the clinical data of 112 patients with intertrochanteric fractures were retrospectively analyzed. There were 63 males and 49 females, aged from 60 to 80 years with an average of 66.2 years. The patients were treated respectively with dynamic hip screws (DHS group, 40 cases), anatomic plate (anatomic plate group, 36 cases) and proximal femoral intramedullary nails (PFN group, 36 cases). The data of each group were collected for statistical analysis on the following aspects: operative time, blood loss volume, clinical healing time of fracture, postoperative complications, and hip functional score of Harris. RESULTS: All these patients were followed up from 20 to 24 months with an average of 22.6 months. There was no significant difference in operative time, blood loss volume among three groups; there was significant difference in clinical healing time of fracture, Harris score and postoperative complications among three groups (P < 0.05). In the healing time, the PFN group was significantly less than that of other groups (P = 0.001), but there was no differences between DHS group and anatomic plate group. In the Harris score, the PFN group was significantly higher than that of other groups (P = 0.001), but there was no differences between DHS group and anatomic plate group. In the aspect of postoperation complication, there was 2 cases of coxa vara, 1 case of internal fixation loosening and 1 case of deep venous thrombosis in the DHS group; there were 2 cases of deep venous thrombosis in the PFN group; there were 2 cases of coxa vara and 1 case of internal fixation loosening in the anatomic plate group (P = 0.001). CONCLUSION: In the treatment of intertronchanteric fractures, proximal femoral intramedullary nail may be the best choice, which can decrease healing time as well as complications postoperatively.

A distal femoral supra-condylar plate: biomechanical comparison with condylar plate and first clinical application for treatment of supracondylar fracture.

PURPOSE: An anatomical supra-condylar plate is designed and analysed by biomechanical testing. METHODS: The biomechanical properties of the supra-condylar and condylar plate were compared in six matched pairs of cadaveric femurs. A transverse osteotomy gap was created to simulate an OTA/AO type A3 supracondylar fracture. The left and right specimens were fitted with supra-condylar and condylar plate, respectively. Nondestructive axial compression, three-point bending and torsion tests were performed, and the peak load of the bone-implant construction was measured. The fracture site suitable for supra-condylar plate application and its correlation with femoral length were calculated. The gender influence on it was also discussed. RESULTS: The difference of stiffness between the supra-condylar and condyle groups were not significant (P > 0.05) at 363.4 and 362.5 N/mm for compression, 229.5 and 237.6 N/mm in the sagittal plane and 195.5 and 188.4 N/mm in the coronal plane for three-point bending, and 7.5 and 7.9 Nm/deg for axial torsion, respectively. The peak load was 4438 ± 136.15 N and 5215 ± 174.33 N, respectively, for the two groups. The average extent of the fracture site suitable for the application of the supra-condylar plate was 70.86 ± 4.61 mm. The femoral length and gender showed no influence on it. CONCLUSION: Despite the limited bone contact area provided by the supra-condylar plate, its construct stiffness is comparable to the condylar plate. The supra-condylar plate can be used to treat carefully-selected extra-articular supracondylar fractures.

[Surgical treatment of discogenic low back pain by minimally invasive transforaminal lumbar interbody fusion combined with unilateral pedicle screw fixation].

OBJECTIVE: To investigate the effectiveness of surgical treatment for discogenic low back pain (DLBP) by minimally invasive transforaminal lumbar interbody fusion (TLIF) combined with unilateral pedicle screw fixation (UPSF). METHODS: Between March 2006 and July 2009, 57 patients with single-level DLBP were treated by minimally invasive TLIF combined with UPSF, including 27 males and 30 females with an average age of 45.6 years (range, 38-61 years) and a disease duration of 3.8 years (range, 9 months to 11 years). The involved segments included L2, 3 in 2 cases, L3, 4 in 5 cases, L4, 5 in 29 cases, and L5, S1 in 21 cases. The operative time, incision length, intraoperative blood loss, postoperative drainage volume, hospitalization times, fusion rate, and complications were observed. The effectiveness were evaluated through Oswestry disability index (ODI) and visual analogue score (VAS), and the operative outcomes were compared in different groups classified according to various pressures of the contrast medium and sensitivities to disc block after inducing consistent pain. RESULTS: The operation time, incision length, blood loss, postoperative drainage volume, and hospitalization times were (84.6 +/- 37.4) minutes, (3.4 +/- 0.6) cm, (132.5 +/- 23.2) mL, (58.7 +/- 21.4) mL, and (6.5 +/- 0.8) days, respectively. All patients were followed up 2 years and 2 months to 5 years and 4 months (mean, 3.2 years). At last follow-up, ODI and VAS scores were significantly improved when compared with preoperative scores (P < 0.05). The effectiveness according to ODI were excellent in 27 cases, good in 22 cases, fair in 6 cases, and poor in 2 cases, with an excellent and good rate of 86.0%. All patients acquired strong interbody fusion. At last follow-up according to ODI and VAS scores, better results were found in patients of low-pressure sensitive group and high-sensitive disc block group (P < 0.05). CONCLUSION: Minimally invasive TLIF combined with UPSF is reliable for DLBP with minimal surgical trauma, less paravertebral tissue injury, and fewer complications, but the indications for operation must be strictly followed. Patients being sensitive to low-pressure or high-sensitive to disc block can achieve better surgical results.

[Surgical treatment of degenerative lumbar instability by minimally invasive transforaminal lumbar interbody fusion].

OBJECTIVE: To investigate the effectiveness of surgical treatment for single-level degenerative lumbar instability (DLI) by comparing traditional open transforaminal lumbar interbody fusion (TLIF) with minimally invasive TLIF. METHODS: Between March 2007 and May 2009, 87 patients with single-level DLI were treated by traditional open TLIF (group A, n = 45) and by minimally invasive TLIF (group B, n = 42), respectively. There was no significant difference in gender, age, disease duration, segment level, combined diseases of lumbar spine, or the proportion of uni- and bilateral symptom between 2 groups (P > 0.05). The indexes of surgical trauma, systemic inflammatory response, clinical outcomes, and paravertebral muscle injury were compared between 2 groups. RESULTS: Operation was performed successfully in all patients. The patients were followed up 2.9 years on average in group A and 2.8 years on average in group B. The incision, blood loss, and postoperative drainage in group B were significantly less than those in group A (P < 0.05), but the operation time in group B was significantly longer than that in group A (P < 0.05). There were significant differences (P < 0.05) in C-reactive protein, leucocyte count, and creatine kinase MM between 2 groups at 24 hours postoperatively as well as in C-reactive protein at 6 days postoperatively; group B was superior to group A. At last follow-up, the Oswestry disability index (ODI) and visual analogue score (VAS) were significantly improved when compared with the preoperative scores in 2 groups (P < 0.05). There were significant differences in ODI and back pain VAS score (P < 0.05), but no significant difference in leg pain VAS score (P > 0.05) between 2 groups. At last follow-up, no low back pain occurred in 8 and 18 cases, mild in 25 and 18 cases, moderate in 9 and 6 cases, and severe in 3 and 0 cases in groups A and B, respectively, showing that low back pain was significantly lighter in group B than in group A (Z = 2.574, P = 0.010). At last follow-up, the atrophy ratio of multifidus muscle was 37% +/- 13% in group A and was 15% +/- 7% in group B, showing significant difference (t = 12.674, P = 0.000). The multifidus muscle atrophy was rated as grade I in 18 and 44 sides, as grade II in 42 and 32 sides, and as grade III in 30 and 8 sides in groups A and B, respectively, showing significant difference (Z = -4.947, P = 0.000). CONCLUSION: Both traditional open TLIF and minimally invasive TLIF are the effective treatments for single-level DLI. Minimally invasive TLIF has less surgical trauma, slighter postoperative systemic inflammatory response, less paravertebral muscle injury, and lower incidence of postoperative back pain, but it has longer operation time.

[Anterior segmental decompression and double-plate fixation for treatment of skip cervical spondylotic myelopathy].

OBJECTIVE: To evaluate the clinical outcomes and values of anterior segmental decompression and double-plate fixation (ASDDF) for treatment of skip cervical spondylotic myelopathy (SCSM). METHODS: Between June 2005 and June 2008, 17 patients with SCSM were treated with ASDDF. There were 10 males and 7 females with an average age of 58.8 years (range, 41-74 years) and an average disease duration of 9.7 months (range, 6-39 months). According to Japanese Orthopaedic Association (JOA) score system, 2 patients were rated as extreme severe condition, 7 as severe, 7 as moderate, and 1 as mild. MRI images showed 42 affected cervical disc levels, including 26 disc levels with high-intensity intramedullary lesions on T2, 4 with low-intensity intramedullary lesions on T1, and 12 with significant cord compression but no signal change; according to Nagata classification scale, there were 5 abnormal segments at class I, 21 at class II, and 16 at class III. The rate of fusion, the Cobb angle, and the range of motion (ROM) of the cervical spine were measured preoperatively and postoperatively by the X-ray examinations. The improvement of the neurological function was evaluated by the JOA score. RESULTS: The average time of follow-up was 28.6 months (range, 24-58 months). After operation, dysphagia occurred in 2 cases (symptom relief after 1 month), hoarseness in 1 case (symptom relief after 3 months of methylcobalamin treatment), and degeneration of adjacent segments without symptom in 3 cases. The X-ray films showed the fusion rate of 100% at 12 months after operation without displacement, resorption or collapse of bone graft, and without breakage or loosening of plate and screw. The Cobb angles were (13.3 +/- 10.4) degrees preoperatively, (15.8 +/- 10.8) degrees immediately postoperatively, and (15.4 +/- 11.4) degrees at last follow-up; the ROM of the cervical spine were (41.3 +/- 17.4) degrees preoperatively and (23.8 +/- 18.8) degrees at last follow-up; and the JOA scores were 8.2 +/- 2.9 preoperatively, 13.7 +/- 3.0 at 12 months postoperatively, and 13.9 +/- 2.8 at last follow-up. All indexes showed significant differences between before operation and after operation (P < 0.05). The results of JOA scores were excellent in 8 cases, good in 6, fair in 2, and poor in 1 with an average improvement rate of 66.8% (range, 14%-88%) for the neurological function. CONCLUSION: Adequate decompression, high rate of fusion, solid mechanical stability, improvement of total cervical lordosis, and the neurological function can be achieved through ASDDF for treatment of SCSM.