【Abstract】 Objective To investigate the possibil ity of BMSCs seeded into collagen Ⅰ -glycosaminoglycan (CG)matrices to form the tissue engineered cartilage through chondrocyte inducing culture. Methods Bone marrow aspirate of dogs was cultured and expanded to the 3rd passage. BMSCs were harvested and seeded into the dehydrothemal treatment (DHT)cross-l inked CG matrices at 1×106 cells per 9 mm diameter sample. The samples were divided into experimental group and control group. In the experimental group, chondrogenic differentiation was achieved by the induction media for 2 weeks. Medium was changed every other day in both experimental group and control group. The formation of cartilage was assessed by HE staining and collagen Ⅱ immunohistochemical staining. Results The examinations under the inverted phase contrast microscopeindicated the 2nd and 3nd passage BMSCs had the similar morphology. HE staining showed the BMSCs in the experimental group appeared polygon or irregular morphology in the CG matrices, while BMSCs in the control group appeared fibroblast-l ike spindle or round morphology in the CG matrices. Extracellular matrix could be found around cells in the experimental group. Two weeks after seeded, the cells grew in the CG matrices, and positive collagen Ⅱ staining appeared around the cells in the experimentalgroup. There was no positive collagen Ⅱ staining appeared in the control group. Conclusion It is demonstrated that BMSCs seeded CG matrices can be induced toward cartilage by induction media.
Objective To investigate the possibility of repairing articular cartilage defects with the mesenchymal stem cells(MSCs) seeded type Ⅰ collagen-glycosaminoglycan(CG) matrices after being cultured with the chondrogenic differentiation medium. Methods The adherent population of MSCs from bone marrow of10 adult dogs were expanded in number to the 3rd passage. MSCs were seeded intothe dehydrothermal treatment (DHT) crosslinked CG matrices; 2×106 cells per 9mm diameter samples were taken. Chondrogenic differentiation was achieved by the induction media for 3 weeks. Cell contractility was evaluated by the measuement of the cell-mediated contraction of the CG matrices with time inculture.The in vitro formation of the cartilage was assessed by an assayemploying immunohistochemical identification of type Ⅱ collagen and by immunohistochemistry to demonstrate smooth muscle actin （SMA）. The cells seededingCGs wereimplanted into cartilage defectsof canine knee joints. Twelve weeks after surgery, the dogs were sacrificed and results were observed. Results There was significant contraction of the MSCsseeded DHT crosslinked CG scaffolds cultured in the cartilage induction medium. After 21 days, the MSCseeded DHT crosslinked matrices were contracted to 64.4%±0.3%; histologically, the pores were found to be compressedandthe contraction coupled with the newly synthesized matrix, transforming the MSCsseeded CG matrix into a solid tissue in most areas. The type Ⅱ collagen staining was positive. The SMA staining was positive when these MSCs were seeded and the contracted CGs were implanted into the cartilage defects of the canine knee joints to repair the cartilage defects. The function of the knee joints recovered and the solid cartilaginous tissue filled the cartilage defects. Conclusion The results demonstrates that MSCs grown in the CG matrices can produce a solid cartilaginous tissuecontaining type Ⅱ collagen after being cultured with the chondrogenic differentiation medium and implanted into cartilage defects. We hypothesize that the following steps can be performed in the chondrogenic process: ①MSCs express SMA, resulting in matrix contraction, thus achieving a required cell density (allowing the cells to operate in a necessary society)； ②Cells interact to form a type Ⅱ collagencontaining extracellular matrix (and cartilaginous tissue)； ③Other factors, suchas an applied mechanical stress, may be required to form a mature cartilage with the normal architecture.
Objective To evaluate the effectiveness of combined posterior decompression with laminoplasty and anterior decompression with fusion for the treatment of cervical spinal canal stenosis with reverse arch. Methods Between May 2009 and February 2012, 13 cases of cervical spinal canal stenosis with reverse arch underwent posterior decompression with laminoplasty surgery in prone position and then anterior decompression with fusion surgery in supine position. There were 7 males and 6 females with an average age of 43.5 years (range, 38-62 years) and an average disease duration of 25 months (range, 18-60 months). All the patients had neck axial symptoms and spinal cord compressed symptoms, and lateral computer radiology (CR) of the neck showed reverse arch of cervical vertebrae. Segments of intervertebral disc protrusion included C3-6 in 4 cases, C4-7 in 4 cases, and C3-7 in 5 cases. After operation, anteroposterior and lateral CR was used to observe the cervical curvature change and fixation loosening, MRI to observe the change of the compression on spinal cord, visual analogue scale (VAS) score to evaluate the improvement of axial symptom, and Japanese Orthopaedic Association (JOA) score to assess the nerve function improvement. Results All incisions healed by first intention. All patients were followed up 9-32 months (mean, 15.4 months). Internal fixator had good position without loosening or breaking and the compression on spinal cord improved significantly after operation. All the patients obtained bony fusion at 6 months after operation. The axial symptoms and the nerve function at last follow-up were improved. VAS score at last follow-up (3.25 ± 1.54) was significantly lower than that at preoperation (6.55 ± 1.52) (P lt; 0.05); JOA score at last follow-up (10.45 ± 4.23) was significantly higher than that at preoperation (7.05 ± 1.32) (P lt; 0.05); and cervical curvature value at last follow-up [(6.53 ± 3.12) mm] was significantly higher than that at preoperation [(3.22 ± 5.15) mm] (P lt; 0.05). Conclusion Combined posterior decompression with laminoplasty and anterior decompression with fusion for the treatment of cervical spinal canal stenosis with reverse arch is a safe and effective surgical method.
Objective To summarize the characteristic imaging signs of ossification of the ligamentum flavum (OLF) associated with dural adhesions by analyzing retrospectively the imaging signs of OLF associated with dural adhesions. Methods A retrospective analysis was made on clinical data of 85 patients undergoing OLF surgery between January 2010 and September 2012. The patients were assigned into the study group and the control group according to the preoperative imaging signs. Of 85 patients, 34 had both “tram track sign” and “jagged line sign” as the study group and 51 had either “tram track sign” or “jagged line sign” and neither of them as the control group. Adherence between dura mater and ligamentum flavum was observed during operation as the “gold standard” for the diagnosis of dural adhesion. The imaging information of CT and MRI in sagittal and axial planes was analyzed. The typical characteristics of dural adhesions were found. Then the sensitivity, specificity, and positive likelihood ratio of the preoperative imaging examinations were calculated to estimate the reference value and diagnostic value (gt; 5 having reference value, and gt; 10 having diagnostic value). Results In the study group, dural adhesion was observed in 26 patients (10 males and 16 females), and the other 8 patients (6 males and 2 females) had no dural adhesion. In the control group, dural adhesion was found in 2 female patients who had “jagged line sign”, and 49 patients had no dural adhesion (14 males and 35 females). In patients having both “tram track sign” and “jagged line sign”, the sensitivity was 92.9%; the specificity was 86.0%; and the positive likelihood ratio was 6.6. In patients having “tram track sign”, the sensitivity was 92.9%; the specificity was 64.9%; and the positive likelihood ratio was 2.6. In patients having “jagged line sign”, the sensitivity was 100%; the specificity was 77.2%; and the positive likelihood ratio was 4.4. Conclusion For patients with OLF having both “tram track sign” and “jagged line sign”, preoperative CT and MRI have a reference value for diagnoses of the OLF associated with dural adhesions.
Objective To investigate the effect of quantitative semi-transected blade on the improvement of spinal cord semi-transected and lump defect model. Methods Forty-eight male Sprague Dawley rats (weighing 220-250 g) were divided into the experimental group (n=24) and control group (n=24). The spinal cord semi-transected and lump defect model was made by self-made quantitative semi-transected blade in the experimental group, and by ophthalmic scalpel in the controlgroup. Then, the complications were observed; the electrophysiological results were detected before modeling and at 21 days after modeling; the histological changes at margin of lump defect were observed at 6 hours, 5 days, and 28 days; Basso, Beattie, and Bresnahan (BBB) scores were detected at 1, 3, 5, 7, 14, 21, 28, 35, 42, 56, and 84 days after modeling. Results There was significant difference in the mortality between the experimental group (0) and the control group (26.67%) (P=0.028). Electrophysiological examination: there was no significant difference in latency and ampl itude of motor evoked potentials (MEP) and sensory evoked potentials (SEP) between 2 groups at preoperation (P gt; 0.05); at 21 days after operation, latencies of MEP and SEP increased and the amplitude decreased in the control group, showing significant differences when compared with those in the experimental group and the preoperative values (P lt; 0.05), but no significant difference was seen between preoperation and postoperation in the experimental group (P gt; 0.05). Histological examination: in the control group, small hematoma could be observed at normal side at 6 hours after modeling, increased spaces of spinal tissue and perineural invasion were observed at 5 days, and small cavity formed without normal motoneurons at 28 days in the margin of lump defect. In the experimental group, no small hematoma could be observed at 6 hours after modeling, no inreversible injury of neuron and small cavity were observed at 5 days, and normal motoneurons were observed without small cavity at 28 days in the margin of lump defect.BBB scores: except the scores between experimental group and control group at affected side (P gt; 0.05), there were significant differences between groups, and between normal side and affected side for intragroup (P lt; 0.05). Conclusion Semi-transected and lump defect model could be set up successfully by self-made quantitate semi-transected blade, procedure is repetitive and the model is stable. This model is an ideal model for semi-transected spinal cord injury.
ObjectiveTo evaluate the effectiveness of cervical single open-door laminoplasty with the unilateral C4,5 foraminotomy for cervical myelopathy in preventing postoperative C5 palsy. MethodsBetween January 2008 and June 2012, 200 consecutive patients with cervical myelopathy and unilateral C4,5 foraminal stenosis were treated, and the clinical data were retrospectively analyzed. Of them, 89 patients underwent cervical single open-door laminoplasty combined with unilateral C4,5 foraminotomy (group A), and 111 patients underwent simple cervical single open-door laminoplasty (group B). There was no significant difference in gender, age, disease duration, segmental lesions, and diagnosis distribution between 2 groups (P>0.05). The operation time, intraoperative bleeding volume, and the incidence of C5 palsy were recorded. The Japanese Orthopaedic Association (JOA) score before and after operation was used for neurological assessment, and the JOA recovery rate was calculated. ResultsThe operation time was (122±29) minutes and the intraoperative bleeding volume was (165±50) mL in group A, which were significantly higher than those in group B[(109±31) minutes and (145±32) mL] (t=3.033, P=0.010;t=3.429, P=0.003). All patients were followed up; the follow-up time was 3-48 months (mean, 25 months) in group A, and was 4-50 months (mean, 27 months) in group B. C5 palsy occurred in 1 patient of group A (1.12%), and in 9 patients of group B (8.11%), showing significant difference between 2 groups (χ2=3.709, P=0.045). The JOA score was significantly improved at 2 weeks and last follow-up after operation when compared with preoperative JOA scores in 2 groups (P<0.05), but no significant was found between at 2 weeks and at last follow-up (P>0.05) in each group. Between group A and group B, no significant difference was found in JOA score and the recovery rate (P>0.05). During follow-up, no persistent axial pain for a long time and obvious spinal instability occurred in 2 groups. ConclusionCervical single open-door laminoplasty with unilateral C4,5 foraminotomy can reduce the incidence of the C5 palsy for patients with cervical myelopathy combined with unilateral C4,5 foraminal stenosis.
ObjectiveTo investigate the effectiveness of selective-partial hemivertebra resection and instrumentation via posterior approach only for congenital kyphoscoliosis. MethodsBetween January 2008 and August 2011, 17 patients with congenital kyphoscoliosis were treated by selective-partial hemivertebra resection and instrumentation via posterior approach. There were 10 boys and 7 girls with the mean age of 10.8 years (range, 9-14 years). Of them, 15 cases had lumbar back pain, and 3 cases had lower limb numbness of nervous system damage symptoms. Risser sign was rated as grade 0 in 3 cases, grade 1 in 2 cases, grade 2 in 7 cases, and grade 3 in 5 cases. The classification of deformity was fully segmental hemivertebra. The deformity located at the thoracic segment in 9 cases, at the thoracolumbar segment in 4 cases, and at the lumbar segment in 4 cases. The Cobb angles of the main curves, segmental curves, and segmental kyphotic curves were measured at pre-operation, at 10 days after operation, and last follow-up to evaluate the correction effect. ResultsThe 2-7 segments (mean, 3.7 segments) were fixed. The operation time was 4-6 hours (mean, 4.77 hours). The intraoperative bleeding was 300-1 100 mL (mean, 611.76 mL). All incisions healed by first intention, with no infection or complication of nervous system. All patients were followed up 6-37 months (mean, 20.12 months). Back pain and numbness of lower limbs were eliminated. X-ray films showed complete bone graft fusion at 6-18 months (mean, 12 months). At 10 days after operation and last follow-up, the Cobb angles of the main curves, segmental curves, and segmental kyphotic curves were significantly decreased compared with the preoperative angles (P<0.05); the Cobb angles of the main curves and segmental curves at last follow-up were significantly greater than those at 10 days after operation (P<0.05) except the segmental kyphotic curves angle (P>0.05). Postoperative correction rates of the Cobb angles of the segmental curve, the main curves, and segmental kyphotic curves were 64.35%±0.07%, 65.08%±0.07%, and 72.26%±0.11%, respectively; loss of correction was (3.04±1.17), (2.81±0.93), and (0.75±0.50)°, respectively. ConclusionFor patients at the age of 9-14 years, with the Risser sign between grade 0-3, and with the Cobb angles less than 60°, the selective-partial hemivertebra resection and instrumentation via posterior approach can balance the growth on the two sides of the spine, and achieve satisfactory therapeutic effect through individualized treatment of extra growth center resection.
Objective To evaluate the biomechanical properties of proximal femoral medial buttress plate (PFMBP) for fixing the reverse oblique intertrochanteric fractures by comparing with proximal femoral locking compression plate (PFLCP) and proximal femoral nail antirotation (PFNA). Methods Eighteen synthetic femoral bone models (Synbone) were divided into 3 groups (group PFLCP, group PFNA, and group PFMBP), 6 models in each group; an AO 31-A3.1 reverse oblique femoral intertrochanteric fracture was made based on the same criterion. After being fixed and embeded, the axial load testing, torsion testing, and axial load-to-failure testing were performed on each model. The axial displacement of different loads, torque of different torsion angles, and failure load of each model were recorded, and the stiffness of axial load and torsion were calculated. Results The axial stiffness in groups PFLCP, PFNA, and PFMBP were (109.42±30.14), (119.13±29.14), and (162.05±22.05) N/mm respectively, showing significant differences between groups (P<0.05). There were significant differences in torque between different torsion angles in the same group, as well as in the torque between groups at the same torsional angle (P<0.05). The torsion stiffness in groups PFLCP, PFNA, and PFMBP were (1.45±0.44), (1.10±0.13), and (1.36±0.32) N·mm/deg respectively; there were significant differences when compared groups PFLCP and PFMBP with group PFNA (P<0.05), but no significant difference was found between group PFLCP and group PFMBP (P>0.05). The failure loads of groups PFLCP, PFNA, and PFMBP were (1 408.88± 0.17), (1 696.56±0.52), and (2 154.65±0.10) N respectively, showing significant differences between groups (P<0.05). Conclusion The newly-designed PFMBP is better than PFNA and PFLCP in axial load stiffness and torsion stiffness for fixing reverse oblique intertrochanteric fracture by biomechanical test, indicating that reconstruction of medial stability is a key element for unstable intertrochanteric fracture.