Objective To investigate the osteoblasts effect, compl ications and influencing factors in the appl ication of small freeze-drying allogeneic bone plots mixed autologous bone fragments in spinal surgery, and to compare with autogenous bone graft. Methods From January 2003 to January 2007, 515 cases of spinal injuries were treated. A total of 324 cases weretreated with small freeze-drying allogeneic bone plots mixed with autologous bone grafts (group A), including 211 males and 113 females with an average age of 36 years (18-83 years). There were 182 cases of thoracolumbar vertebra fracture, 68 cases of lumbar spondylol isthesis, 47 cases of lumbar vertebral canal stenosis, 17 cases of cervical disc herniation, 5 cases of cervical spine fracture-dislocation and 5 cases of thoracolumbar vertebra tumor. The weight of bone graft was 10-60 g (mean 30 g). A total of 191 cases were treated with autogenous bone grafting (group B), including 135 males and 56 females with an average age of 32 years (23-78 years). There were 109 cases of thoracolumbar vertebra fracture, 23 cases of lumbar spondylol isthesis, 17 cases of lumbar vertebral canal stenosis, 19 cases of cervical disc herniation, and 23 cases of cervical spine fracture-dislocation. The weight of bone graft was 10-50 g (mean 25 g). Results In group A, effusion of wound increased in 4 cases and the result of bacterial culture was negative; effusion was absorbed after 2 weeks of local irrigation, drainege and cortin management. In group B, no obvious effusion was observed. The follow-up time was 10-36 months (mean 17.4 months) in group A and 8-36 months (mean 16.8 months) in group B. The bone heal ing was achieved in 308 cases within 4-10 months (mean 8.1 months) and in 184 cases within 4-10 months (mean 5.8 months), and the bone fusion rates were 95.06% and 96.34% in groups Aand B, respectively. There was no significant difference in bone fusion rate between groups (P gt; 0.05). According to Mankin and Komender evaluation standard, the response rates were 95.06% and 96.34% in groups A and B, respectively, showing no significant difference (P gt; 0.05). Conclusion Mix-bone grafting has the same effective to autologous bone grafting in bone fusion rate. It could be used as the supplement of the autologous bone inadequacy.
Objective To investigate the stability and the stress distributions of L3-5 fused with three different approaches (interbody, posterolateral and circumferential fusions) and to investigate degeneration of thesegment adjacent to the fused functional spinal unit. Methods A detailed L3-5 three-dimensional nonlinear finite element model of a normal man aged 32 was established and validated. Based on the model, the destabilized model, the interbody, posterolateral and circumferential fusions models of L4-5 were established. After the loadings were placed on all the models, we recorded the angular motions of the fused segment and the Von Mises stress of the adjacent intervertebral disc. Results The circumferential fusion was most stable than the others, and the interbody fusion was more stable than the posterolateral fusion. The maximal Von Mises stress of the adjacent L3,4 intervertebral disc in all the models was ranked descendingly as flexion,lateral bending,torsion and extension. For the three kinds of fusions, the stress increment of the L3,4 intervertebral disc was ranked ascendingly as interbody fusion,posterolateral fusion and circumferential fusion. Conclusion After destabilization of the L4,5 segment, the stability of the circumferential fusionis better than that of the others, particularly under the flexional or extensional loading. The stability of the interbody fusion is better than that of the posterolateral fusion, except for under the flexional loading. The feasibility of adjacent segment degeneration can be ranked descendingly as: circumferential fusion,posterolateral fusion and interbody fusion.
ObjectiveTo observe the effect of stromal vascular fraction cells (SVFs) from rat fat tissue combined with sustained release of recombinant human bone morphogenetic protein-2 (rhBMP-2) in promoting the lumbar fusion in rat model.MethodsSVFs were harvested from subcutaneous fat of bilateral inguinal region of 4-month-old rat through the collagenase I digestion. The sustained release carrier was prepared via covalent bond of the rhBMP-2 and β-tricalcium phosphate (β-TCP) by the biominetic apatite coating process. The sustained release effect was measured by BCA method. Thirty-two rats were selected to establish the posterolateral lumbar fusion model and were divided into 4 groups, 8 rats each group. The decalcified bone matrix (DBX) scaffold+PBS, DBX scaffold+rhBMP-2/β-TCP sustained release carrier, DBX scaffold+SVFs, and DBX scaffold+rhBMP-2/β-TCP sustained release carrier+SVFs were implanted in groups A, B, C, and D respectively. X-ray films, manual spine palpation, and high-resolution micro-CT were used to evaluate spinal fusion at 8 weeks after operation; bone mineral density (BMD) and bone volume fraction were analyzed; the new bone formation was evaluated by HE staining and Masson’s trichrome staining, osteocalcin (OCN) was detected by immunohistochemical staining.ResultsThe cumulative release amount of rhBMP-2 was about 40% at 2 weeks, indicating sustained release effect of rhBMP-2; while the control group was almost released within 2 weeks. At 8 weeks, the combination of manual spine palpation, X-ray, and micro-CT evaluation showed that group D had the strongest bone formation (100%, 8/8), followed by group B (75%, 6/8), group C (37.5%, 3/8), and group A (12.5%, 1/8). Micro-CT analysis showed BMD and bone volume fraction were significantly higher in group D than groups A, B, and C (P<0.05), and in group B than groups A and C (P<0.05). HE staining, Masson’s trichrome staining, and immunohistochemistry staining for OCN staining exhibited a large number of cartilage cells with bone matrix deposition, and an active osteogenic process similar to the mineralization of long bones in group D. The bone formation of group B was weaker than that of group D, and there was no effective new bone formation in groups A and C.ConclusionThe combination of sustained release of rhBMP-2 and freshly SVFs can significantly promote spinal fusion in rat model, providing a theoretical basis for further clinical applications.
To explore the advantage and indication of combined anterior and posterior surgeries for lumbarsacral junction tuberculosis. Methods Eleven cases of the lumbarsacral junction tuberculosis were treated with combined anterior (radical debridement and autograft) and posterior (instrumentation and fusion) surgeries in one stage between January 2002 and December 2006. There were 9 males and 2 females with the age of 20-56 years old. The courseof disease was 4 to 15 months, 6 months on average. The lessons were located at L5, S1 in 7 patients, at L4,5, S1 in 2 patients and at L5, S2 in 2 patients. The involved vertebral bodies were at 2 segments in 7 patients; and 3 segments in 5 patients. The preoperative kyphosis was 5 to 8° with an average 9°. The sinus was associated in 3 patients, 3 patients had radiculopathy; 4 had paeumonophthisis and 9 had abscess. Results The followed-up period was from 6 months to 3 years, 18 months on average. According to Chen score, among the 11 cases, there were excellent in 9, good in 2. All incisions were healed up primarily. After operation, spinal fusion was achieved in 10 cases within 5 months to 7 months, 6 months on average, and pseudoarthrosis in 1 case was found by the CT examination. The postoperative kyphosis was 0 to 4° with the mean of 2° and the radiculopathy in 3 cases all got nerve function recovery. Conclusion Lumbarsacral junction tuberculosis treated with this surgical technique can achieve a high satisfactory rate with restoring the spinal stabil ity, arresting the disease early, providing early fusion, correcting the kyphosis and preventing progression of kyphosis particularly if lumbosacral spine tuberculosis is associated with sinus or preoperative diagnosis cannot exclude suppurative spondyl itis.
Objective To analyze the cl inical features of scol iosis associated with Chiari I malformation in adolescent patients, and to explore the val idity and safety of one-stage posterior approach and vertebral column resection for the correction of severe scol iosis. Methods Between October 2004 and August 2008, 17 adolescent patients with scol iosis associated with Chiari I malformation were treated with surgical correction through posterior approach and pedicle instrumentation. There were 9 males and 8 females with an average age of 15.1 years (range, 12-19 years). The MRI scanning showed that 16 of 17 patients had syringomyel ia in cervical or thoracic spinal cord. Apex vertebra of scol iosis were located atT7-12. One-stage posterior vertebral column resection and instrumental correction were performed on 9 patients whose Cobb angle of scol iosis or kyphosis was more than 90°, or who was associated with apparent neurological deficits (total spondylectomy group). Other 8 patients underwent posterior instrumental correction alone (simple correction group). All patients’ fixation and fusion segment ranged from upper thoracic spine to lumbar spine. Results The operative time and the blood loss were (384 ± 65) minutes and (4 160 ± 336) mL in total spondylectomy group, and were (246 ± 47) minutes and (1 450 ± 213) mL in simple correction group; showing significant differences (P lt; 0.05). In total spondylectomy group, coagulation disorder occurred in 1 case, pleural perforation in 4 cases, and lung infection in 1 case. In simple correcction group, pleural perforation occurred in 1 case. These patients were improved after symptomatic treatment. All patients were followed up 24-36 months (32.5 months on average). Bony heal ing was achieved at 6-12 months in total spondylectomy group. No breakage or pull ingout of internal fixator occurred. The angles of kyphosis and scol iosis were significantly improved at 1 week after operation (P lt; 0.01) when compared with those before operation. The correction rates of scol iosis and kyphosis (63.4% ± 4.6% and 72.1% ± 5.8%) in total spondylectomy group were better than those (69.4% ± 17.6% and 48.8% ± 19.3%) in simple correction group. Conclusion Suboccipital decompression before spine deformity correction may not always be necessary in adolescent scol iosis patients associated with Chiari I malformation. In patients with severe and rigid curve or apparente neurological deficits, posterior vertebral column resection would provide the opportunity of satisfied deformity correction and decrease the risk of neurological injury connected with surgical correction.
Objective To introduce operation skill of the spinal wedge osteotomy by posterior approach for correction of severe rigid scol iosis and to discuss the selection of the indications and the range of fusion and fixation. Methods Between July 1999 and January 2009, 23 patients with severe rigid scol iosis were treated with spinal wedge osteotomy by posterior approach, including 16 congenital scol iosis, 5 idiopathic scol iosis, and 2 neurofibromatosis scol iosis. There were 11 males and 12 females with a median age of 15 years (range, 8-29 years). Two patients had previous surgery history. The Cobb’s angles of scol iosis and kyphosis before operation were (85.39 ± 13.51)° and (56.78 ± 17.69)°, respectively. The mean spinal flexibil ity was 14.4% (range, 4.7%-22.5%). The trunk shift was (15.61 ± 4.89) mm. The preoperative CT or MRI showed bony septum in the canal in 2 patients. Results The mean operative time was 241 minutes and the mean blood loss was 1 452 mL. The average fused vertebrae were 10.7 segaments (range, 8-14 segaments). The follow-up ranged from 1 to 4 years with an average of 2 years and 6 months. The postoperative Cobb’s angle of scol iosis was (38.70 ± 6.51)°, the average correction rate was 54.7%. The postoperative Cobb’s angle of kyphosis was (27.78 ± 6.01)°, the average correction rate was 51.0%. The trunk shift was improved to (4.69 ± 1.87) mm, the increased height was 5.2 cm on average (range, 2.8-7.7 cm). The Cobb’s angle of scol iosis was (41.57 ± 6.80)° with an average 2.9° loss of correction at the final follow-up; the Cobb’s angle of kyphosis was (30.39 ± 5.94)° with an average 2.6° loss of correction at the final follow-up; the trunk shift was (4.78 ± 2.00) mm at the final follow-up. There were significant differences (P lt; 0.05) in the Cobb’s angles of scol iosis and kyphosis and the trunk shift between preoperation and postoperation, between preoperation and last follow-up. Four cases had pedicle fracture, 1 had L1 nerve root injury, 2 had superior mesenteric artery syndrome, 1 had exudates of incision, and 2 had temporary dysfunction of both lower extremity. Conclusion Spinal wedge osteotomy by posterior approach is a rel iable and safe surgical technique for correcting severe rigid scol iosis. With segmental pedical screw fixation, both the spinal balance and stabil ity can be restored.
Objective To evluate the clinical outcome of autograftsof ilium and interbody fusion cage or bone morphogenetic protein(BMP)／artificial bone material／ cage in treating lumbar spondylolisthesis. Methods From January 1997 to January 2004，114 patients with lumbar spondylolisthesis were treated with posterior lumbar interbody fusion and pedicle screw fixation． There were 45 males and 69 females with an average age of 43 years ranging from 32 to 61 years. Of 114patients, 85 cases were classified as degree Ⅰ, 24 cases as degree Ⅱ and 5 cases as degree Ⅲ. The patients were divided into three groups accordingto the material used for interbody fusion: autografts of ilium (group A, n=42), interbody fusion cages(group B, n=36), and BMP／artificial bone material／ cage (group C, n=36)．The clinical and radiographic results of the patients were compared among three groups． Results All patients were followed from 13 to 30 months with an average of 15 months． There were no statistically significant differences in surgical time, blood loss, and disc space height of preoperation(P＞0.05) among three groups. No severe complication occurred in the three groups(P＞0.05). The excellent and good rates in groups A，B and C were 81.0％, 80.6％, and 83.3％ respectively, showing no statisticallysignificant difference(P＞0.05)．The fusion rate of group C(97.0%) was significantly higher than those of group A(81.0%) and group B(83.3%) (P＜0.05) after 1 year of operation．And the average loss of disc space height in groups B and C was significantly lower than that in group A(P＜0.05). Conclusion Higher fusion rate and lower loss of disc space height can beobtained in treating lumbar spondylolisthesis with BMP／artificial bone materiel.It is an effective method in the treatment of spondylolisthesis.
Objective To discuss operative strategies of posterior deformity vertebra resection and instrumentation fixation in the treatment of congenital scol iosis or kyphoscol iosis in child and adolescent patients, and to evaluate the surgicalresults. Methods From May 2003 to December 2007, 28 patients with congenital scol iosis or kyphoscol iosis were treatedwith one stage posterior deformity vertebra resection. There were 11 males and 17 females with an average age of 9.6 years (1.5-17.0 years). The locations were thoracic vertebra in 13 cases, thoracolumbar vertebra in 10 cases, and lumbar vertebra in 5 cases. All the patients underwent one stage posterior deformity vertebra resection, fusion and correction with pedicle instrumentation. According to different types of deformities, the patients underwent three different surgeries: hemivertebra resection (13 patients), hemivertebra resection combined contralateral unsegmental resection (7 patients), and total vertebral column resection (8 patients). Based on short or long segmental pedicle instrumentation, deformities were corrected and fixed, in 7 patients with short segmental fixation (group A), in 13 patients with long segmental fixation with hemivertebra resection or combined contralateral unsegmental resection (group B), and in 8 patients with long segmental fixation with total vertebral column resection (group C). The operative duration and the volume of blood loss were recorded, and the correction rate was calculated through measurement of Cobb angles of scol iosis and kyphosis before and after operation. Results The operation time of groups A, B, and C was (98 ± 17), (234 ± 42), and (383 ± 67) minutes, respectively, and the blood loss during operation was (330 ± 66), (1 540 ± 120), and (4 760 ± 135) mL, respectively; showing significant differences among three groups (P lt; 0.05). All patients achieved one-stage heal ing of incision. No deep infection, respiratory failure or deep vein thrombosis occurred. One patient had the signs of ischemical reperfusion injury of spinal cord 6 hours after operation and recovered after 2 weeks of relative therapy in group C; no neurological compl ication occurred in other patients. The mean follow-up period was 32.8 months (24-72 months). Intervertebral rigid fusion was identified from radiological data 6 months after operation according to contiguous callus crossed intervertebral gap and maintenance of correction results. No instrumentation failure occurred. There were significant differences in the Cobb angle between before and after operations (P lt; 0.01). There were significant differences in the corrective rate of scol iosis between groups A, B and group C (P lt; 0.05). Meanwhile, there were significant differences in the corrective rate of kyphosis between groups A, C and group B (P lt; 0.05). Conclusion One-stage posterior deformity vertebra resection has a good capabil ity of correcting congenital scol iosis or kyphoscol iosis on coronal and sagittal plane rel ied on removal deformity origin. It is important to select appropriated strategies on deformity resection and segmental fixation according to different ages and deformity situations of patient.