Objective To explore the feasibilities, methods, outcomes and indications of atlas pedicle screw system fixation and fusion for the treatment of upper cervical diseases. Methods From October 2004 to January 2006, 17 patients with upper cervical diseases were treated with atlas pedicle screw system fixation and fusion. There were 13 males and 4 females, ageing 19 to 52 years. Of 17 cases, there were 14 cases of atlantoaxial dislocation(including 3 cases of congenital odontoid disconnection，4 cases of old odontoid fracture，2 cases of new odontoid fracture(typeⅡC), 3 cases of rupture of the transverse ligament, and 2 cases of atlas fracture； 2 cases of tumor of C2; 1case of giant neurilemoma of C2,3 with instability after the resection oftumors. JOA score before operation was 8.3±3.0. Results The mean operative time and bleeding amount were 2.7 hours (2.1-3.4 hours) and 490 ml (300-750 ml) respectively. No injuries to the vertebral artery and spinal cord were observed. The medial-superior cortex of lateral mass was penetrated by 1 C1 screw approximately 3 mmwithout affecting occipito-atlantal motions. All patients were followed up 3-18 months. The clinical symptoms were improved in some extents and the screws were verified to be in a proper position, no breakage or loosening of screw and rob occurred. All patients achieved a solid bone fusion after 3-6 months. JOA score 3 months after operation was14.6±2.2. JOA improvement rates were 73%-91%(mean 82%). Conclusion The atlas pedicle screw system fixation and fusion is feasible for the treatment of upper cervical diseases and has betteroutcomes, wider indications if conducted properly.
Objective To evaluate pulmonary function changes in patients with severe scol iosis undergoing anterior release, posterior segmental fixation and fusion, and convex thoracoplasty by resecting a short length of rib. Methods FromJanuary 2006 to July 2007, 16 patients with severe scol iosis were treated with anterior release, posterior segmental fixation and fusion, and convex thoracoplasty by resecting a short length of rib. There were 6 males and 10 females with an average age of 16.9 years (range, 10-24 years). There were 1 case of Lenke 1 curve, 9 cases of Lenke 2 curve, and 6 cases of Lenke 4 curve. The preoperative Cobb angle was (104.8 ± 10.9)° and the preoperative thoracic kyphotic angle was (30.0 ± 4.2)°. The preoperative height of “razor back” deformity was (5.9 ± 1.2) cm. Before operation, the actual value of forced vital capacity (FVC) was (2.04 ± 0.63) L and that of forced expiratory volume in 1 second (FEV1.0) was (1.72 ± 0.62) L. The percentage of actual values to expected ones in FVC was 70% ± 16%, and that in FEV1.0 was 67% ± 15%. All patients had pulmonary function tests before operation and 3, 6, 12, 24 months after operation. Results All wounds healed by first intention. The Cobb angle at 24-month follow-up was (53.4 ± 18.6)° and the correction rate was 49.0% ± 15.3%. The thoracic kyphotic angle at 24-month follow-up was (34.0 ± 2.4)° and the correction rate was 13.3% ± 2.2%. The height of “razor back” deformity at 24-month follow-up was (2.2 ± 0.8) cm. Compared with preoperative level, all these data showed significant differences (P lt; 0.05). At 3 and 6 months, the actual values of FVC and FEV1.0 decl ined, but no significant difference was found (P gt; 0.05). At 12 and 24 months, the actual values of FVC andFEV1.0 were close to the preoperative level (P gt; 0.05). The percentages of actual values to expected ones in FVC and FEV1.0 indicate continued improvement in pulmonary function from the postoperative 3 to 24 months follow-up. Compared with preoperative level, the percentages of actual values in FVC decl ined 19% 3 months postoperatively (P lt; 0.05) and 12% 6 months postoperatively (P lt; 0.05). The percentages of actual values to expected ones in FEV1.0 decl ined 16% 3 months postoperatively (P lt; 0.05), and 10% 6 months postoperatively (P lt; 0.05). The percentages of actual values to expected ones in FVC and FEV1.0 were close to the preoperative level 12 and 24 months after operation (P gt; 0.05). Conclusion In severe scol iosis patients who are treated with anterior release, posterior segmental fixation and fusion, and convex thoracoplasty by resecting a short length of rib, pulmonary function decreases obviously 3-6 months after operation. And it returns to the operative baseline 12-24 months after operation.
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 compare the effectiveness of three different bone grafts [autogenous bone, allogeneic bone, and bone morphogenetic protein (BMP) composite bone] combined with screw system for spinal fusion of degenerative lumbardisease. Methods Between January 2005 and January 2010, 102 cases of degenerative lumbar disease were randomly treated with autogenous bone (group A, n=35), allogeneic bone (group B, n=33), and BMP composite bone (group C, n=34). There was no significant difference in sex, age, disease duration, affected segments, Meyerding grade, preoperative intervertebral space height, and the Japanese Orthopaedic Association (JOA) score among 3 groups (P gt; 0.05). The intervertebral space height, bone fusion rate, and JOA score were compared among 3 groups at different time points. Results All patients of 3 groups were followed up 2 to 5 years, with an average of 3.2 years. At 6 to 24 months after operation, the intervertebral space height significantly increased when compared with preoperative value in 3 groups (P lt; 0.05); the intervertebral space height of groups A and C was significantly greater than that of group B at 6, 12, 18, and 24 months after operation (P lt; 0.05), but no significant difference was found between groups A and C (P gt; 0.05). Bone graft fusion was observed at 6 months in groups A and C and at 12 months in group B; at 24 months, the rate of bone graft fusion was 100% in groups A and C, and 87.88% in group B, showing significant difference (P lt; 0.05). There was significant difference in JOA score between preoperation and postoperative 12th and 24th months (P lt; 0.05); at 12 and 24 months after operation, JOA socre and improving rate of groups A and C were significantly higher than those of group B (P lt; 0.05), but no significant difference was found between groups A and C (P gt; 0.05). Conclusion The effect of BMP composite bone is equivalent to that of autogenous bone graft in treating spinal fusion of degenerative lumbar disease, and they are better than allogeneic bone graft. BMP composite bone can obtain adequate bone grafts without invasive sampling, and has fast fusion and high successful rate.
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.
Objective To discuss the main points of technique and the range of fusion in posterior operation of spinal stenosis associated with lumbar degenerative kyphosis (LDK). Methods The cl inical data were retrospectively analysedfrom 20 cases of spinal stenosis associated with LDK which were performed posterior operation from February 2001 to February 2008. There were 1 male and 19 females, aged 52-81 years old with an average of 64 years old. The course of disease was 6-10 years. All patients had severe low back pain. According to Frankel’s neurologic function classification, there were 18 cases of grade E and 2 cases of grade D before operation. The apex of LDK included L1 in 3 cases, L2 in 10 and L3 in 7. The operational method was decided according to different characteristics of LDK. All patients were divided into three groups. Group 1 included 6 cases of sciatica and intermittent claudication with worse physical status, the segmental decompression of spinal canal, posterior intervertebral fusion and short transpedical instrument fixation were performed. Group 2 included 8 cases whose Cobb angle of LDK was less than 20°, the segmental decompression of spinal canal, posterior intervertebral fusion and one-level or multilevel lamina osteotomy were performed, instrumentation-assisted correction was used. Group 3 included 6 cases whose Cobb angle of LDK was more than 20°, the canal decompression and one-level transvertebral wedge osteotomy were performed, instrumentation-assisted correction, intervertebral fusion and posterior-lateral fusion were used. Results Incision healedby first intention in all patients. One patient suffered from superior mesenteric artery syndrome at 6 hours after operationand healed after symptomatic management. The neurologic function was improved to grade E at 2 weeks after opeartion. All patients were followed-up 24-54 months (average 26 months). At last follow-up，the Oswestry Disabil ity Index of all patients was 30.5% ± 9.6%; showing significant difference when compared with preoperation (55.9% ± 11.8%, P lt; 0.05). The back pain scoring and leg pain scoring were 2.8 ± 1.6 and 2.4 ± 1.6, respectively according to the Numeric Rating Scale score; showing significant differences when compared with preoperation (7.5 ± 0.5 and 7.3 ± 0.7, P lt; 0.05). The Numeric Rating Scale score and Oswestry Disabil ity Index in all patients were improved obviously when compared with before operation (P lt; 0.05). During the follow-up period, there was no instrumentation failure or correction loss and the fusion rate was up to 100%. Conclusion For spinal stenosis associated with LDK patients, the most important therapic purpose is to improve cl inical symptom through reconstruction lumbar stabil ization and spinal biomechanics l ine in sagittal plane. Overall estimate of the cl inical appearance and imageology character is necessary when making decision of which segments needed to be fixation and fusion. Individual ized treatment strategy may be the best choice.
Objective To evaluate the biomechanical characteristicsof titanium mesh with anterior plate fixation or ilium autograft in anterior cervical decompression.Methods Six fresh cervical spine specimens(C3-7) of young cadaver were used in the biomechanical test. After C5, C5,6 and C4-6 were given vertebrectomy,ilium autograft and titanium mesh with anterior plate fixation were performed. Their stabilities of flexion,bilateral axial rotation,the lateral bending and the extension were tested. Intact cervical spine specimens served as control group. Results Ilium autograft improved the stability of the unstable cervical vertebrae and decreased the flexion, the lateral bending or the extension, showing a significant difference when compared with control group(Plt;0.05). Whereas, axial rotational motion was decreased insignificantly(Pgt;0.05). Titanium meshwith anterior plate fixation improved the stability of the unstable spine and decreased the flexion,the bilateral axial rotation,the lateral bending or the extension, showing a significant difference when compared with control group(Plt;0.05). Conclusion The vertebrectomy and anterior cervical fusion by ilium autograft was the least stable construct of all modes tested,and the titanium mesh implantation is stabler than the intact cervical sample.
Objective
To investigate the relationship between the volume of bone-graft and fusion efficacy in posterior lumbar interbody fusion and internal fixation of spondylolisthesis.
Methods
Between May 2004 and June 2007, 79 patients with spondylolisthesis were treated with posterior lumbar interbody fusion and internal fixation. The patients were randomly divided into 3 groups according to the volume of bone-graft for interbody fusion: group A (n=27), 5 bone granules/ cm3 on average; group B (n=26), 11 bone granules/cm3 on average; and group C (n=26), 25 bone granules/cm3 on average. There was no significant difference in gender, age, disease duration, affected segment, and the degree of vertebral slip among 3 groups (P gt; 0.05). The volume of bone-graft, the fusion rate, the loss of intervertebral height, and the incidence of internal fixation failure were compared among 3 groups.
Results
All cases were followed up 24-43 months (mean, 35 months). There were significant differences in volume of bone-graft among 3 groups (P lt; 0.05). There was no significant difference in total volume of bone-graft and Cage height among 3 groups (P gt; 0.05). The Oswestry disability index (ODI) and visual analogue scale (VAS) scores of low back pain and leg pain at last follow-up were significantly decreased when compared with preoperative scores in 3 groups (P lt; 0.05); but no significant difference was found among 3 groups (P gt; 0.05). The fusion rate was significantly higher in group B than in groups A and C, and in group A than in group C at 1 and 2 years after operation (P lt; 0.05). The change values of the intervertebral height were (2.2 ± 1.4), (0.8 ± 1.3), and (2.3 ± 1.6) mm respectively in groups A, B, and C; it was significantly lower in group B than in groups A and C (P lt; 0.05). The degree of vertebral slip at immediately after operation and last follow-up was significantly improved when compared with preoperative one in 3 groups (P lt; 0.05); the loss of vertebral slip in group B was significantly lower than that in groups A and C at last follow-up (P lt; 0.05). After operation, nail breaking occurred in 1 case (3.7%) of group C at 1 year, depinning in 1 case (3.8%) of group A at 2 years, and no nail breaking or depinning in group B. There was no significant difference in the incidence of internal fixation failure among 3 groups (χ2=3.950, P=0.604).
Conclusion
The application of bone-graft with middle volume (11 bone granules/cm3 on average) in internal fixation and posterior lumbar interbody fusion has a good imageology outcome, which can increase the fusion rate and decrease the loss of intervertebral height.
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.
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.
