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Objective:To evaluate the clinical effects of posterior reduction in the treatment of acute severe traumatic lumbar spondylolisthesis.Methods:A retrospective study was conducted to analyze the clinical data of 12 patients with acute severe traumatic lumbar spondylolisthesis who had been treated by posterior reduction at Department of Spinal Surgery, Zhengzhou Orthopaedic Hospital from June 2010 to December 2018. There were 7 males and 5 females with an age of (25.7±1.8) years. The spondylolisthesis was at L4 in 4 cases and at L5 in 8 cases, and grade Ⅲ in 7 cases, grade Ⅳ in 4 cases and grade Ⅴ in 1 case according to the Meyerding classification. By the American Spinal Injury Association (ASIA) grading, the preoperative neurological function was at level B in 6 cases, at level C in 4 cases, and at level D in 2 cases. All the 12 patients underwent posterior reduction and internal fixation with pedicle screws, as well as intervertebral bone graft fusion. Operation time and intraoperative blood loss were recorded. Clinical efficacy was evaluated by visual analogue scale (VAS) and Oswestry disability index (ODI) before and after surgery, and neurological function was evaluated by ASIA grading. X-ray, CT plain scan and reconstruction were used to observe internal fixation and bone grafting.Results:All patients were followed up for (18.5±2.1) months. The operation time was (165.7±42.3) min and the blood loss (497.7±75.3) mL. The VAS pain scores [(2.7±0.3) points and (1.8±0.2) points] and ODIs (18.2%±2.3% and 14.5%±2.6%) at 2 weeks after operation and at the last follow-up were significantly lower than the preoperational values [(8.5±0.6) points and 72.3%±12.3%] ( P<0.05), but there was no statistically significant difference between 2 weeks after operation and the last follow-up ( P>0.05). At the last follow-up, X-rays and CT scans showed good fixation and adequate bone grafting; the spondylolisthesis was grade 0 in 10 cases and grade I in 2 cases; the ASIA level of neurological function was C in 2 cases, D in 3 cases, and E in 7 cases. Healing of surgical incision was delayed in 2 patients but responded to symptomatic treatment. Follow-ups observed no such complications as loosening or pulling out of internal fixation. Conclusion:In the treatment of acute severe traumatic lumbar spondylolisthesis, posterior reduction can effectively restore the spondylolisthesis sequence and restore spinal stability, leading to satisfactory curative outcomes.
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Objective:To compare the efficacies of posterior long segment instrumentation combined with transpedicular impaction bone grafting or with bone cement augmentation in treating stage III Kümmell disease.Methods:A retrospective cohort study was conducted to analyze the clinical data of 38 patients with stage III Kümmell disease who were admitted to Zhengzhou Orthopedic Hospital between January 2016 and December 2020. The study included 8 male and 30 female patients, with ages ranging from 59 to 81 years [(68.9±4.9)years]. The vertebral fractures occurred at T 8 in 1 patient, T 11 in 9 patients, T 12 in 10 patients, and L 2 in 10 patients. Seventeen patients underwent posterior long segment instrumentation combined with transpedicular impaction bone grafting (impaction bone grafting group), and 21 patients underwent posterior long segment instrumentation combined with bone cement augmentation (bone cement group). The surgical duration, intraoperative blood loss, and incidences of postoperative complications were compared between the two groups. Additionally, the visual analogue score (VAS), Japanese orthopedic association (JOA) score, and Cobb angle were compared before the operation, at 1 week and 3 months post-operation, and at the final follow-up for both groups. The study also compared bone healing at the last follow-up and postoperative complication rates between the two groups. Results:All the patients were followed up for 24-35 months [(28.7±2.9)months]. The impaction bone grafting group had a surgical duration of (150.7±25.4)minutes and intraoperative blood loss of (285.3±48.6)ml, significantly different from those in the bone cement group [(132.0±21.1)minutes, (251.4±44.8)ml] (all P<0.05). Before the operation, there were no significant differences in the VAS, JOA score, or Cobb angle between the two groups (all P>0.05).The VAS was (3.2±0.8)points, (2.7±0.5)points and (2.2±0.7)points in the impaction bone grafting group and was (2.7±0.6)points, (2.6±0.7)points and (2.4±0.8)points in the bone cement group at 1 week and 3 months post-operation and at the final follow-up, respectively. The VAS in the impaction bone grafting group was significantly higher than that in the bone cement group at 1 week post-operation ( P<0.05); however, no significant differences were found at 3 months post-operation or at the last follow-up (all P>0.05). There was no significant difference in the JOA score between the two groups at 1 week or 3 months post-operation, or at the final follow-up (all P>0.05). The Cobb angle in the impaction bone grafting group was (5.1±1.3)°, (5.9±1.8)° and (6.5±2.5)° at 1 week and 3 months post-operation, and at the final follow-up, significantly lower than that in the bone cement group [(8.4±1.6)°, (12.6±2.1)°, and (14.5±3.3)°] (all P<0.01). All the patients in the impaction bone grafting group achieved bone healing at the last follow-up. One patient in the impaction bone grafting group experienced delayed incision healing, whereas two patients in the bone cement group had poor bone healing. The complication rate was 5.9% (1/17) in the impaction bone grafting group and 9.5% (2/21) in the bone cement group ( P>0.05). Conclusions:Posterior long segment instrumentation combined with transpedicular impaction bone grafting or with bone cement augmentation are both effective in alleviating pain and improving the spinal function for stage III Kümmell disease. The former procedure is associated with longer surgical duration and increased intraoperative blood loss, but it can provide superior correction and maintenance of kyphosis deformity, promoting the healing of the injured vertebrae.
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Objective:To compare the clinical efficacies of precision targeted and traditional percutaneous vertebroplasty (PVP) in the treatment of refracture of injured vertebra after operation for Kümmell disease.Methods:A retrospective cohort study was conducted to analyze the clinical data of 23 Kümmell disease patients suffering from refracture of injured vertebra after PVP in Zhengzhou Orthopedic Hospital from October 2014 to October 2018. The patients included 7 males and 16 females, aged 53-89 years [(69.3±3.5)years]. There were 11 patients of stage I Kümmell disease and 12 patients of stage II Kümmell disease. The vertebral distribution of fracture was T 11 (3 patients), T 12 (9 patients), L 1 (8 patients) and L 2 (3 patients). Eleven patients received traditional PVP treatment (traditional PVP group) and 12 patients received precision targeted PVP treatment (targeted PVP group). The operation time, amount of bone cement injection and filling of bone cement in the fracture space were compared between the two groups. The visual analogue score (VAS) and Oswestry disability index (ODI) were also compared before operation, at 2 days, 1 month, 3 months, 6 months after operation, and at the last follow-up. The rates of bone cement leakage and re-collapse of injured vertebra were observed in the two groups. Results:The patients were followed up for 12-36 months [(24.2±2.6)months]. There were no significant differences in the operation time or amount of bone cement injection between the two groups (all P>0.05). All the fracture spaces in the targeted PVP group were fully filled with bone cement, while 4 patients in the traditional PVP group showed inadequate filling of the fracture area ( P<0.05). The VAS values in the targeted PVP group were (8.9±0.5)points, (1.6±0.2)points, (1.7±0.1)points, (1.8±0.1)points, (1.9±0.3)points, and (1.8±0.4)points before operation, at 2 days, 1 month, 3 months, 6 months after operation and at the last follow-up; and those in the traditional PVP group were (9.1±0.9)points, (1.8±0.4)points, (1.8±0.2)points, (2.0±0.4)points, (2.1±0.2)points, and (2.4±0.3)points, respectively. The VAS values of both groups were significantly decreased at 2 days, 1 month, 3 months, 6 months after operation, and at the last follow-up compared with those before operation (all P<0.05), but there was no significant difference between different time points after operation (all P>0.05). No significant differences were found in the VAS values between the two groups before operation and at 2 days, 1 month, 3 months and 6 months after operation (all P>0.05). However, the VAS value in the targeted PVP group was significantly lower than that in the traditional PVP group at the last follow-up ( P<0.05). The ODI values in the targeted PVP group were 38.5±4.3, 7.2±2.3, 7.3±2.0, 7.2±1.8, 7.3±2.4, and 7.4±2.5 before operation and at 2 days, 1 month, 3 months, 6 months after operation, and at last follow-up; and those in the traditional PVP group were 37.8±4.1, 7.5±2.5, 7.7±1.9, 7.9±2.4, 8.1±2.6, and 9.6±2.4, respectively. The ODI values of both groups were significantly decreased at 2 days, 1 month, 3 months, 6 months after operation and at the last follow-up compared with those before operation (all P<0.05), but there were no significant differences between different time points after operation (all P>0.05). The ODI values were not significantly different between the two groups before operation and at 2 days, 1 month, 3 months, 6 months after operation (all P>0.05), but the ODI value in the targeted PVP group was significantly lower than that in the traditional PVP group at the last follow-up ( P<0.05). There were no significant differences in the rates of bone cement leakage or re-collapse of injured vertebra between the two groups (all P>0.05). Conclusion:Compared with traditional PVP treatment for refracture of injured vertebra after operation for Kümmell disease, targeted PVP can make bone cement injection fully dispersed, greatly reduce pain and promote functional recovery.
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Objective:To investigate the efficacy of the classified reduction based on CT two-dimensional images for the surgical treatment of single segment facet joint dislocation in subaxial cervical spine.Methods:A retrospective case series study was made on 105 patients with single segment facet joint dislocation in subaxial cervical spine admitted to Zhengzhou Orthopedic Hospital from January 2015 to October 2022. There were 63 males and 42 females, with the age range of 22-78 years [(47.5±3.6)years]. Preoperative American Spinal Cord Injury Association (ASIA) classification was grade A in 23 patients, grade B in 45, grade C in 22, grade D in 15 and grade E in 0. The classification of surgical approach was based on the presence or not of continuity between anterior and posterior subaxial cervical structures and the movability of the posterior cervical facet joint on CT two-dimensional images, including anterior cervical surgery if both were presented and posterior facet joint resection plus anterior cervical surgery if there was discontinuity between anterior and posterior subaxial cervical structures or posterior facet joint fusion. Reduction procedures were applied in accordance with the type of facet joint dislocation classified based on the position of the lower upper corner of facet joint, including skull traction or manipulative reduction for the dislocation locating at the dorsal side (type A), intraoperative skull traction and leverage technique for the dislocation locating at the top (type B) and intraoperative skull traction and leverage technique with boosting for the dislocation locating at the ventral side (type C). If the dislocation of two facet joints in the same patient was different, the priority of management followed the order of type C, type B and type A. The reduction success rate, operation time and intraoperative blood loss were recorded. The cervical physiological curvature was evaluated by comparing the intervertebral space height and Cobb angle before operation, at 3 months after operation and at the last follow-up. The fusion rate of intervertebral bone grafting was evaluated by Lenke grading at 3 months after operation. The spinal cord nerve injury was assessed with ASIA classification before operation and at 3 months after operation. Japanese Orthopedic Association (JOA) score was applied to measure the degree of cervical spinal cord dysfunction before operation and at 3 months after operation, and the final follow-up score was used to calculate the rate of spinal cord functional recovery. The occurrence of complications was observed.Results:All patients were followed up for 3-9 months [(6.0±2.5)months]. The reduction success rate was 100%. The operation time was 40-95 minutes [(58.6±9.3)minutes]. The intraoperative blood loss was 40 to 120 ml [(55.7±6.8)ml]. The intervertebral space height was (4.7±0.3)mm and (4.7±0.2)mm at 3 months after operation and at the last follow-up, significantly decreased from preoperative (3.1±0.5)mm (all P<0.01), but there was no significant difference in intervertebral space height at 3 months after operation and at the last follow-up ( P>0.05). The Cobb angle was (6.5±1.3)° and (6.3±1.2)° at 3 months after operation and at the last follow-up, significantly increased from preoperative (-5.4±2.2)° (all P<0.01), but there was no significant difference in Cobb angle at 3 months after operation and at the last follow-up ( P>0.05). The fusion rate of intervertebral bone grafting evaluated by Lenke grading was 100% at 3 months after operation. The ASIA grading was grade A in 15 patients, grade B in 42, grade C in 29, grade D in 12 and grade E in 7 at 3 months after operation. The patients showed varying degrees of improvement in postoperative ASIA grade except that 15 patients with preoperative ASIA grade A had partial recovery of limb sensation but no improvement in ASIA grade. The JOA score was (13.3±0.6)points and (13.1±0.6)points at 3 months after operation and at the last follow-up, significantly improved from preoperative (6.8±1.4)points (all P<0.01), but there was no significant difference in JOA score at 3 months after operation and at the last follow-up ( P>0.05). The rate of spinal cord functional recovery was (66.3±2.5)% at the last follow-up. All patients had no complications such as increased nerve damage or vascular damage. Conclusion:The classified reduction based on CT two-dimensional images for the surgical treatment of single segment facet joint dislocation in subaxial cervical spine has advantages of reduced facet joint dislocation, recovered intervertebral space height and physiological curvature, good intervertebral fusion and improved spinal cord function.
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Objective:To compare the clinical effect of transpedicular impaction and grafting of allogeneic bone containing enriched bone marrow combined with posterior internal fixation and posterior subtotal vertebrectomy combined with posterior internal fixation in the treatment of stage III Kümmell′s disease.Methods:A retrospective cohort study was made on clinical data of 40 patients with stage III Kümmell′s disease admitted to Zhengzhou Orthopedic Hospital from June 2015 to December 2018. There were 10 males and 30 females, at age range of 57-79 years［(67.7±6.1)years］. A total of 19 patients were treated by transpedicular impaction and grafting of allogeneic bone containing enriched bone marrow combined with posterior internal fixation (impaction bone graft group), and 21 patients by posterior subtotal vertebrectomy combined with posterior internal fixation (subtotal vertebrectomy group). Operation time and intraoperative blood loss were compared between the two groups. Degree of pain, lumbar dysfunction and degree of kyphosis were evaluated by visual analogue scale (VAS), Japanese Orthopedic Association (JOA) score and kyphotic Cobb angle before operation, at 1 week after operation and at the last follow-up. Bone healing time was compared between the two groups. The complications of the two groups were observed.Results:All patients were followed up for 25-64 months［(40.6±10.4)months］. Operation time and intraoperative blood loss were (130.0±10.1)minutes and (284.5±43.5)ml in impaction bone graft group, lower than those in subtotal vertebrectomy group［(253.8±33.2)minutes, (889.1±95.7)ml］(both P<0.01). There were no significant differences in VAS, JOA score or kyphotic Cobb angle between the two groups before operation, at 1 week after operation and at the last follow-up (all P>0.05). Both VAS and JOA score showed significant differences within each group at any time point (all P<0.01). In both groups, the kyphotic Cobb angle reduced significantly at 1 week after operation when compared with that before operation (all P<0.01), and the angle showed a slight increase at the last follow-up, but remained significantly lower than that before operation (all P<0.01). There were no relapse of pain or aggravation of kyphosis. Bone healing time in impaction bone graft group［4.4(4.0, 5.0)months］was significantly shorter than that in subtotal vertebrectomy group［6.4(5.2, 8.1)months］( P<0.01). There were 2 patients with delayed healing of surgical incision in impaction bone graft group, with the complication rate of 11%. There were 2 patients with dural tear and 3 patients with delayed healing of surgical incision in subtotal vertebrectomy group, with the complication rate of 24%. The complication rate was not statistically significant between the two groups ( P>0.05). No loosening or breakage of internal fixation was observed during the follow-up. Conclusions:Transpedicular impaction and grafting of allogeneic bone containing enriched bone marrow combined with posterior internal fixation and posterior subtotal vertebrectomy combined with posterior internal fixation are effective in the treatment of stage III Kümmell disease. However, the former can shorten the operation time, reduce the intraoperative blood loss and accelerate the healing of injured vertebral bone, suggesting a relatively minimally invasive surgical method for reconstruction and maintenance of spinal biomechanical stability.
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Objective:To investigate the efficacy of stage I anterior cervical reduction, decompression, interbody fusion and internal fixation of single-segment lower cervical injury of AO type C subtype F4.Methods:A retrospective case series study was made on 45 patients with single-segment lower cervical injury of AO C type F4 subtype admitted to Zhengzhou Orthopedic Hospital from January 2012 to December 2019. The study included 31 males and 14 females with the age of (48.5±3.7)years (range, 23-78 years). Segment of injury was located at C 4/5 in 11 patients, at C 5/6 in 19, and at C 6/7 in 15. Under general anesthesia, all patients (16 unilateral injury and 29 bilateral injury) underwent stage I anterior cervical reduction, decompression, interbody fusion and internal fixation within 24 hours after injury. The interbody fusion methods included autogenous iliac bone in 28 patients and cervical fusion cage in 17. The operation time, blood loss, reduction time and correction rate of zygapophysial joints, postoperative complications and incision healing were analyzed. The height of cervical intervertebral space and Cobb angle were measured through X-ray of lateral cervical vertebrae before operation and3 months after operation to assess the cervical physiological curvature. The type of injury was clarified according to Lenke classification through coronal and sagittal CT scanning to determine the intervertebral bone graft fusion rate. The intraspinal spinal cord decompression was observed through MRI. The nerve function was assessed before operation and 3 months after operation using American Spinal Injury Association (ASIA) scale and Japanese Orthopedic Association (JOA) score, and the improvement rate was measured. Results:All the patients were followed up for (6.1±3.6)months (range, 3-9 months). The operation time was (55.1±8.2)minutes (range, 40-75 minutes), and intraoperative blood loss was (45.2±5.3)ml (range, 40-80 ml). The Zygapophysial joint reduction took (2.1±0.5)minutes (range, 1.5-3.0 minutes), with a success rate of 100%. Surgical procedures were performed with no postoperative complications such as aggravated spinal cord injury, large vascular injury or esophageal lesion. All the patients obtained Class I incision healing at first stage. The height of cervical intervertebral space was improved from preoperative (3.3±0.6)mm to (4.9±0.8)mm at postoperative 3 months ( P<0.05). The Cobb angle was increased from preoperative (-4.6±3.6)° to (6.5±2.1)° at postoperative 3 months ( P<0.01). According to Lenke classification, the intervertebral body fusion was good at postoperative 3 months, including Grade A in 41 patients and Grade B in 4. The rest of the patients showed varying degrees of neurological recovery according to ASIA scale, except for 6 patients with ASIA Grade A. The JOA score was improved from preoperative (7.4±2.3)points to (15.0±3.2)points at postoperative 3 months ( P<0.05), with the improvement rate of (73.3±17.6)%. Conclusion:For stage I anterior cervical reduction, decompression, interbody fusion and internal fixation of single-segment lower cervical injury of AO type C subtype F4, early surgical decompression is needed so as to reduce the perched facet or dislocated zygapophyseal joints and effectively improve the cervical spinal cord function.
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Objective:To compare the clinical efficacy of long/short segment posterior instrumentation combined with transpedicular impaction bone grafting for stage III Kümmell's disease.Methods:A retrospective case control study was conducted to analyze the clinical data of 45 patients with stage III Kümmell's disease admitted to Zhengzhou Orthopaedics Hospital from June 2012 to June 2019, There were 8 males and 37 females, aged 58-84 years [(68.8±3.5)years]. Segment of injury was T 11 in 5 patients, T 12 in 18, L 1 in 15, and L 2 in 7. A total of 24 patients were treated with posterior long segment pedicle screw fixation combined with pedicle screw compression and bone grafting (long segment group), and 21 patients were treated with posterior short segment pedicle screw fixation combined with pedicle screw compression and bone grafting (short segment group). For patients with severe osteoporosis, pedicle screws were augmented with bone cement. The operation time and blood loss were compared between the two groups. The visual analogue scale (VAS) was used to evaluate the degree of low back pain, and the Japanese Orthopaedic Association (JOA) score was used to evaluate the lumbar function at postoperative 2 weeks and 1 year. According to X-ray film and CT examination, the bone healing of the grafted vertebral body and the changes of Cobb angle of injured vertebrae were further evaluated. The complications were observed. Results:All patients were followed up for 15-48 months[(31.2±2.3)months]. There were no significant differences between the two groups in operation time and intraoperative blood loss ( P>0.05). The bone grafts in the vertebrae healed well in both groups at 1 year after operation. The Cobb angle, VAS and JOA score in both groups improved at 2 weeks and 1 year after operation ( P<0.01). There was no significant difference in Cobb angle, VAS and JOA score between the two groups at 2 weeks after operation ( P>0.05). The Cobb angle in short segment group [(14.8±6.3)°] was significantly higher than that in long segment group [(8.5±3.3)°] at 1 year after operation ( P<0.01), but there was no significant difference in VAS and JOA scores between the two groups ( P>0.05). There was no loosening or breakage of internal fixation in both groups. Conclusions:For stage III Kümmell's disease, both long and short segment posterior instrumentation combined with transpedicular impaction bone grafting can effectively restore the vertebral height, improve kyphosis and reduce dysfunction. However, long segment can better maintain spine stability, prevent vertebral collapse and progression of local kyphosis Cobb angle when compared with short segment fixation.
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Objective To investigate the safety and effect of zoning laminectomy for the ossification of thoracic ligamentum flavum.Methods From November 2011 to December 2014,34 patients (15 males,19 females;41-76 years old,average 55.0±8.1) with ossification of thoracic ligamentum flavum (OLF) were treated by zoning laminectomy.The course of disease ranged from 1 month to 123 months (average 16.5 months).According to the anatomical characteristics and the pathological ossification process of the thoracic ligamentum flavum,we proposed the concept of "zoning",which divided each segmental thoracic OLF into three zones:"safety zone","middle zone" and "risk zone".From the features of anatomy of LF and process of OLF development,we found there is no or less cerebrospinal fluid between spinal cord and the tip of each ossified nodular masses in severe OLF,any procedures using instruments in this area have the potential to cause irreversible spinal cord injury,we defined this area as "risk zone",the "null" area of each lamina and lateral and dorsal side of nodular masses as "safety zone",and the other area as "middle zone".From "safety zone" to "risk zone" the spinal canal decreased gradually,different zone needs different surgical strategy:This surgical procedure first removed the "null" area of superior and inferior lamina and dorsal side of each segmental OLF.Next,partially or totally resected the "middle zone",exploring the lateral side of nodular masses,and the "risk zone" was exposed and isolated.Finally,dissected the lateral side of nodular masses,and then the "risk zone" was floated and resected with a directly decompressing the spinal cord.Preoperative and postoperative modified Japanese Orthopedic Association (JOA) score and neurologic functional recovery ratio were used to evaluate the surgical outcomes.Results Of the total 83 decompressed OLF segments,5 (6.0％) located in the upper thoracic spine (T1-T4),8 (9.6％) in the midthoracic spine (T5-T8),and 70 (84.4％) in the lower thoracic spine (Tg-L 1).The followed up ranged from 4 to 40 months,with an average of 21.7±9.9 months.The mean JOA score increased significant from 5.3±2.0 preoperatively to 8.8±1.8 at the final follow-up (t=1 1.566,P=0.001).Postoperative average JOA neurologic functional recovery rates were 63.2％±24.7％,including excellent in 15 cases,good in 11 cases and fair in 8 cases.The excellent and good rate was 76.5％.Twelve cases had transient CSF leakage because of dural defect.The dural defect was only treated by tightly suturing the paraspinal muscles,the subcutaneous tissue,and the skin layers.The CSF leakage lasted for 6 to 8 days after operation.Two cases with wound infection were treated with debridement and antibiotics and healed completely.One case with thoracic spinal cord transient incomplete paralysis due to a post-operative epidural hematoma was treated with an emergency operation and got recovered neurological function.Conclusion Zoning laminectomy has the advantages of safe manipulation and thorough decompression,which is an effective choice for the surgical treatment of thoracic OLF.
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Objective To observe the effect of novel tissue engineered nerve grafts, which combined silk fi-broin/collagen scaffold with a co-culture of Schwann cells(SCs)and adipose-derived stem cells(ADSCs), to repair rat sciatic nerve defects. Methods From February, 2015 to August, 2016, the culture and purify SCs and ADSCs were isolated. And co-cultured at a ratio of 2∶1 and introduced into a silk fibroin (SF)/collagen scaffold to construct a tissue-engineered nerve conduit (TENC), which were transplanted to bridge 10 mm long sciatic nerve defects in rats. The experiment was divided randomly into 4 groups (10 rats/group): those bridged with plain SF/collagen scaffolds (Scaffold group), those bridged with TENCs (TENC group), those bridged with autografts (Autograft group) and those unoperated side (Normal group). The mechanical properties were examined using a universal testing machine(Instron 5865). Scanning electron microscopy was performed to observe the structure of the SF/collagen scaffold and the cells' growth. A series of electrophysiological examinations and morphological analyses were performed 12 weeks after surgery to evaluate the effect of the TENC on peripheral nerve regeneration.And One-way ANOVA was used to ana-lyze the data. If the differences between groups were statistically significant, the Turkey's method was further applied for comparison. Results The plain SF/collagen scaffold showed appropriate pore size and good intercommunicating of holes. The cells were tightly attached to and partly coiled about the scaffold and exhibited either a spindle or a spherical shape. The results of the mechanical measurement revealed that the maximum and average Young’s moduli of the SF/collagen scaffold were (10.80 ± 0.30) MPa and (8.14 ± 0.20) MPa, respectively. The mechanical properties ensure that the scaffold could resist muscular contraction and maintain its shape unchanged for a considerable period of time after grafting.All rats in each group had achieved nerve defect regeneration in varying degrees.But in terms of the effect of the repaired nerve, those treated with TENC were similar to those with autologous nerve grafts but superior to those with plain SF/collagen scaffolds. Conclusion The TENC that combined silk fibroin/collagen scaffold with a co-culture of SCs and ADSCs had normal nerve-like structure, and can bridge sciatic nerve defect and promote nerve growth.
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BACKGROUND:The cervical pedicle screws provide ideal three-column stability for cervical vertebra, but there is stil no a standard with the choice of pedicle screw place methods in cervical vertebra. Here, we try to seek a simpler, safer and accurate pedicle screw place method.OBJECTIVE:To evaluate the accuracy and security of transpedicular screw placement assisted by rapid prototyping individual navigation template. METHODS:Eight cadaver cervical specimens (C3-6) were selected to take CT-scan and data were saved in DICOM format. Three-dimensional (3D) software MIMICS was used to establish the C3~6 3D model, and designed the best pedicle screw channel. According to the morphological feature of the posterior cervical spine elements, the reverse template was designed. Then, the best pedicle screw channels were fused into bilateral navigation template. The navigation template was manufactured by rapid prototyping, and saved in STL format. Rapid prototyping technology was used to print out the navigation template. Cervical pedicle screws were inserted with the assistance of navigation templates fitted with the posterior structure of the vertebral body. Postoperative X-ray and CT scan were used to evaluate the accuracy of screw placement. RESULTS AND CONCLUSION:(1) Total y 64 screws were inserted with the assistance of individual navigation templates. Of them, 62 screws were completely in the pedicle;1 screw perforated the medial cortex of pedicle;1 screw perforated the lateral cortex of pedicle. Accuracy of screw placement was 97%. (2) The individual navigation template with a high accuracy rate is a feasible and safe method for cervical pedicle screw placement, which has great prospects for clinical application.