Treatment of Denis type B thoracolumbar burst fractures by anterior single segmental decompression and instrumentation through Endoring self-support retractor-assisted minimally invasive small incision approach / 中华创伤杂志

Objective To evaluate the clinical efficacy of anterior single segmental decompression and instrumentation through Endoring self-support retractor-assisted minimally invasive small incision approach in the treatment of Denis type B thoracolumbar burst fractures.Methods A retrospective case series study was made on 26 cases (14 males and 12 females,mean age of 48.5 years) of Denis type B thoracolumbar burst fractures treated by anterior single segmental decompression and instrumentation through Endoring self-support retractor-assisted minimally invasive small incision approach from January 2007 to June 2009.Age was 18-68 years (mean,48.5 years).The fractured vertebrae included T1 in three cases,L1 in 18 and L2 in five.The neurological status was Grade C in eight cases,Grade D in 12 cases and Grade E in six cases according to American Spinal Injury Association (ASIA) classification.The operation duration,blood loss and incision length were recorded.The neurological function,lower back pain were evaluated by visual analogue score (VAS),correction of kyphosis and restoration of the fractured vertebral body height followed and documented at 3,6 and 9 months and annually after surgery.The healing of the graft was assessed using Brantigan method based on 3-dimensional computed tomography at final follow-up.Results All patients were successfully managed with this approach.The operation duration was (214.6 ± 30.5)min,and the intraoperative blood loss was (389.7 ± 57.1) ml.The length of incision was (8.5 ± 1.3) cm.All patients were followed up for (6.3 ± 0.4) years.At final follow-up,the neurological functions of all patients with incomplete neurological deficit were improved for at least one grade.The VAS of lower back pain was improved from preoperative (7.8-± 1.6) points to (2.1 ± 0.8) points at final follow-up (P ＜ 0.05).The height of the intervertebral body was restored from preoperative (29.8 ± 5.3) mm to (35.2 ± 2.4) mm at final follow-up (P ＜ 0.05).The kyphosis was corrected from preoperative (20.4 ± 11.7) ° to (11.3 ± 5.5) ° at final follow-up (P ＜ 0.05).Bone fusion was achieved in all patients,with no looseness,breakage or displacement of internal fixation at follow-up.Conclusions Anterior single segmental decompression and instrumentation through Endoring self-support retractor-assisted minimally invasive small incision approach can reduce the surgical trauma,achieve complete spinal canal decompression,adjust kyphosis,fix segment,obtain high rate of bone graft fusion and hence is a safe and effective method with minimal invasion for Denis type B thoracolumbar burst fractures.

Adenovirus-mediated RNA interference against core binding factor alpha 1 inhibits the hypertrophic differentiation of chondrocytes / 中国组织工程研究

BACKGROUND:Hypertrophic differentiation of chondrocytes is the sign of starting endochondral ossification, and it is also an essential step in endochondral ossification, which is a cascade reaction and difficult to be blocked once started. The end result is the formation of bone structure. RNA interference is a post-transcriptional gene silencing. Relevant studies have shown that the use of RNA interference to block the expression of core binding factorα1 (Cbfα1) can effectively inhibit the formation of heterotopic ossification. OBJECTIVE:To use RNA intereference technology to suppress Cbfα1 expression so as to achieve the purpose of blocking the hypertrophic diferentiation of chondrocytes. METHODs: We constructed an adenovirus containing siRNA against Cbfα1 (Ad-Cbfα1-siRNA). Retinoic acid and interleukin-1α were used to induce hypertrophic differetiation of chondrocytes, and then Ad-Cbfα1-siRNA was utilized to inhibit the hypertrophic differentiation of chondrocytes. Immunohistochemistry method was used to analyze the expression of Cbfα1. RESULTS AND CONCLUSION:After induction with retinoic acid and interleukin-1α, the chondrocytes in the negative control virus group appeared to have hypertrophy and the expression of Cbfα1 was positive. In the Ad-Cbα1-siRNA group, the expression of Cbfα1 was negative. These findings suggest that the inhibition of Cbfα1 by RNA interference can be a powerful way to prevent the hypertrophic differentiation of chondrocytes .

Effectiveness of nano-hydroxyapatite/polyamide 66 cage in anterior spinal reconstruction: a mid-term study / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the mid-term effectiveness of nano-hydroxyapatite/polyamide66 (n-HA/PA66) cage in the anterior spinal reconstruction.</p><p><b>METHODS</b>There were 177 patients who undergone the anterior decompression and fusion with n-HA/PA66 cage and internal fixation between January 2008 and January 2010 included in this study. There were 117 male and 60 female patients aged from 18 to 74 years. The diagnoses included cervical fracture in 47 patients, thoracic or lumbar fracture in 50 patients, cervical spondylopathy in 58 patients, spinal tuberculosis in 17 patients and spinal tumor in 5 patients. The X-ray and three-dimensional CT were followed up in all these patients to observe the spinal alignment, the rate of fusion and the rate of n-HA/PA66 cage subsidence and translocation. The neurological functions of patients with spinal fracture were evaluated by Frankel grading; the improvement of the clinical symptoms of the other patients were assessed by visual analogue scale (VAS) scores and Japan Orthopaedic Association (JOA) scores or SF-36 scores.</p><p><b>RESULTS</b>All the 177 patients had been followed-up for 36 to 70 months after surgery (average 51 months). Except the slight cage translocation been found in the only one patient with cervical fracture, no cage prolapsed or breakage was exist in our patients up to the last follow-up. In the patients with spinal fracture, the mean time for fusion was 4.5 months, the rate of fusion was 95.9% and the rate of cage subsidence was 5.2%; while in the patients with cervical spondylopathy, the mean time for fusion was 4.4 months, the fusion rate was 96.5% and the subsidence rate was 5.2%; while in patients with spinal tuberculosis, the mean fusion time was 5.5 months, the rate of fusion was 94.0%, the rate of subsidence was 5.9%; and in the patients with tumor, the mean time for fusion was 6.0 months, the fusion rate was 100%, and the cage subsidence was found in only one patient. The preoperative symptoms of each patient were improved to varying degrees after surgery. At the last follow-up, the Frankel grading of patients of spinal fracture with incomplete paralysis improved 0 to 2 classes; the VAS, JOA or SF-36 scores of the other patients were improved significantly than their respective scores before surgery (t = 2.982, 4.126 and 3.980, P < 0.05).</p><p><b>CONCLUSIONS</b>The n-HA/PA66 cage has much higher rate of osseous fusion and lower cage subsidence, it is an ideal cage which can provide effective restoring and maintaining for the spinal alignment and intervertebral height. Moreover, the mid-term clinical results of anterior reconstruction with this cage in the patients with spinal trauma, degeneration, tuberculosis or tumor are well content.</p>

Management of esophageal fistula caused by anterior cervical spine surgery / 中华骨科杂志

Objective To evaluate cause,treatment and prevention of esophageal fistula caused by anterior cervical spine surgery.Methods Between January 2004 and December 2011,2348 patients underwent anterior cervical spine surgery.Among them,5 patients suffered from esophageal fistula owing to operation,including 3 males and 2 females,with an average age of 34 years (range,14 to 48 years).The diagnosis of these patients included 3 cases of cervi(c)al injury,1 case of cervical spondylosis and 1 case of cervical tuberculosis.There was 1 patient whose esophageal injury was founded during the surgery,and that was directly repaired.For another 4 patients,esophageal fistulas were founded after operation; one case underwent debridement and orificium fistulae repair; one case only underwent debridement; one case underwent debridement and second-stage removal of hardware; and one case underwent debridement and second-stage removal of hardware and esophageal repair with sternocleidomastoid flap.Postoperative treatment included esophageal rest,enteral nutrition,wound drainage,and antibiotic administration.Methylene blue was used to evaluate status of orificium fistulae.Results All patients with esophageal fistula were cured 9 to 61 weeks after treatment,and oral intake was achieved.They were followed up for 6-48 months.There was no recurrence of esophageal fistula,cervical instability and infectious spondylitis in any ease.All patients were satisfied with swallowing function and outcome of cervical spine diseases.The Frankel grade was improved averagely one grade in patients with cervical injury,and the JOA score was improved from preoperative 9 points to postoperative 15 points in patients with cervical spondylosis.Conclusion Successful management of esophageal fistula caused by anterior cervical spinal surgery depends on primary closure of the perforation with or without muscle flaps,surgical drainage,esophageal rest and nutrition support,and removal of hardware if necessary.Prevention consists of the careful operation and gentle tissue handling.

Convex short length rib resection in thoracic adolescent idiopathic scoliosis.

BACKGROUND: Although it brings satisfactory rib hump correction, concomitant thoracoplasty with surgical correction of scoliosis decreases pulmonary function values. To achieve satisfactory rib hump correction and avoid impairment to pulmonary function, we design a new kind of thoracoplasty-convex short length rib resection (CSLRR). This study is to evaluate the effect and outcome of CSLRR in conjunction with pedicle screw instrumentation. METHODS: Seventy patients with thoracic adolescent idiopathic scoliosis treated by pedicle screw instrumentation were retrospectively analyzed after a minimum follow-up of 2 years. Patients were divided into 3 groups: C-T group (conventional thoracoplasty, n =20), N-T group (no thoracoplasty, n=24), and CSLRR group (n=26). Patients were evaluated for height of rib hump, deformity correction, balance, pulmonary function, and complications. RESULTS: The correction rates of hump height were 74.1% in the C-T group, 47.1% in the N-T group, and 63.2% in the CSLRR group, respectively. The CSLRR group showed significantly better correction of rib hump than the N-T group. In thoracic hypokyphosis correction, the CSLRR group was superior to the N-T group with statistical significance. There were no significant differences in proximal thoracic, main thoracic and lumbar Cobb angle, coronal and sagittal balance, and lumbar lordosis at the final follow-up among 3 groups. Three months after the operation, both absolute values and percent-predicted values of forced vital capacity and forced expiratory volume in 1 second in the N-T group and CSLRR group were better than that in the C-T group. Two years after the operation, absolute values of forced vital capacity and forced expiratory volume in 1 second in the N-T group and CSLRR group were better than that in the C-T group. There were 2 hemothorax in the C-T group and 1 pleural effusion in the CSLRR group. CONCLUSIONS: CSLRR showed significantly better rib hump and thoracic hypokyphosis correction without pulmonary function compromise in the treatment of thoracic adolescent idiopathic scoliosis with pedicle screw instrumentation. LEVEL OF EVIDENCE: Therapeutic-level IV retrospective study.

Small intestine submucosa as a scaffold for cartilage reconstruction in vitro / 生物医学工程学杂志

This paper is aimed to investigate the feasibility of applying the small intestine submucosa (SIS) as the scaffold in constructing tissue engineering cartilage in vitro. We obtained SIS from the small intestine of specific pathogen-free pigs. Then we isolated tunica submucosa layer from the mucosal, muscular, and serosal layers by gentle mechanic abrasion. The SIS was made acellular by combination of detergent and enzyme digestion. The chondrocytes were seeded onto the SIS and were cultured for 3 weeks. The cell growth, attachment and distribution were detected by histochemical stain, immunohistochemical stain and scan electron microscope. The chondrocytes could adhere and grow well on the matrix surface, and synthesize a large of the GAG and type U collagen. However, the chondrocytes grew only on the surface andsuperficial layer of the scaffold, they did not move into the inner part of the scaffold. It could be concluded that SIS has good cellular compatibility without cytotoxicity and provides temporary substrate to which these anchorage-dependent cells can adhere, and stimulate the chondrocytes anchored on the scaffold to proliferate and keep differentiated phenotype. Further study will be needed to promote the ability of chondrocyte chemotaxis in order to distribute the chondrocytes into the whole scaffold uniformly.

Surgical treatment of kyphosis in children in healed stages of spinal tuberculosis.

BACKGROUND: Very less literature focuses on the treatment of kyphosis in healed stages of spinal tuberculosis (TB), especially in children. The purpose of this study was to evaluate the outcomes of anterior release, decompression, deformity correction, and instrumented fusion, followed by posterior osteotomy, deformity correction, and pedicle screw instrumented fusion, which is used to treat kyphosis in children in healed stages of spinal TB. METHODS: Sixteen children with kyphotic deformity of the spine in healed stages of TB underwent anterior release, decompression, deformity correction, and instrumented fusion, followed by posterior osteotomy, deformity correction, and pedicle screw instrumented fusion between 2003 and 2007 with at least 2 years of follow-up. Radiologic assessment including the angle of kyphosis and scoliosis, and neurologic status using the modified Frankel grade were analyzed before surgery, after surgery, and at the last follow-up. Fusion was evaluated on flexion-extension lateral radiographs. RESULTS: Good cosmetic results were achieved in all patients. Neurologic improvement was shown in all 4 patients with paraplegia. The mean preoperative angle of kyphosis was 55.8 degrees that reduced to 21.7 degrees, postoperatively. The difference in the mean angle of kyphosis was statistically significant (P<0.05). The mean angle of kyphosis at the last follow-up was 23.2 degrees. The mean correction loss was 1.5 degree, and there was no statistically significant difference in the mean angles of kyphosis between the postoperative and last follow-up measurements. The mean preoperative angle of scoliosis was 6.9 degrees that reduced to 0.8 degree postoperatively. The difference in the mean angle of scoliosis was statistically significant (P<0.05). The mean angle of scoliosis at the last follow-up was 0.9 degree. The mean correction loss was 0.2 degree and there was no statistically significant difference in the mean angles of scoliosis between the postoperative and last follow-up measurements. All patients returning for follow-up had bony fusion. There were no cases of failure of fixation. CONCLUSIONS: Combined anterior and posterior osteotomy, deformity correction, and instrumented fusion halted progression of kyphosis and improved neurologic symptoms. LEVEL OF EVIDENCE: Therapeutic-level IV, retrospective study.

Analysis of the effect of renal replacement therapy on the wound of crush syndrome:experiences during Wenchuan earthquake / 中国矫形外科杂志

[Objective]To analyze the effect of renal replacement therapy on the wound of crush syndrome patients,and to provide better clinic evidence for scheduling the therapy strategy of crush syndrome.[Method]The clinic data of patients suffering from crush syndrome during Wenchuan earthquake were collected and classified into Group A treated by renal replacement therapy and Group B theraped by other treatments except renal replacement therapy.Wound infection rate,wound active artery bleeding occurrence,and the volume of oozes in fasciotomy wound between these two groups were compared.[Result]There was statistically significant difference in the rate of wound infection between Group A and Group B(P=0.006).The most common pathogens were acinetobacter spp,pseudomonas aeruginosa,and enterobacter spp in Group A,and these pathogens were all multi drug-resistant.There was statistically significant difference in the volume of oozes in incisive wound between these two groups(P=0.000).[Conclusion]Renal replacement therapy would increase the volume of oozes,raise the rate of wound infection,and be susceptiblely infected by multi drug-resistant pathogen.

Preliminary Study of Mesenchymal Stem Cells-Seeded Type Ⅰ Collagen-Glycosaminoglycan Matrices for Cartilage Repair / 中国修复重建外科杂志

Objecttive 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 of 10 adult dogs were expanded in number to the 3rd passage. MSCs were seeded into the dehydrothennal treatment (DHT) cross-linked CG matrices; 2 × 106 cells per 9-mm 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 in culture. The in vitro formation of the cartilage was assessed by an assay employing immunohistochemical identification of type Ⅱ collagen and by immunohistochemistry to demonstrate smooth muscle actin (SMA).The cells seededing CGs were implanted into cartilage defects of canine knee joints. Twelve weeks after surgery, the dogs were sacrificed and results were observed. Results There was significant contraction of the MSCs-seeded DHT cross-linked CG scaffolds cultured in the cartilage induction medium. After 21 days, the MSC-seeded DHT cross-linked matrices were contracted to 64.4% ± 0.3%; histologically, the pores were fotmd to be compressed and the 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 tissue containing 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 collagen-containing extracellular matrix (and cartilaginous tissue); ④Other factors, such as an applied mechanical stress, may be required to form a mature cartilage with the normal architecture.