Is Short Same-Segment Fixation Really Better than Short-Segment Posterior Fixation in the Treatment of Thoracolumbar Fractures?

STUDY DESIGN: A retrospective study. OBJECTIVE: This retrospective study assessed whether short same-segment fixation (SSSF) is better than short-segment posterior fixation (SSPF) for reducing thoracolumbar fractures, improving the kyphosis angle, maintaining vertebral height, or reducing the incidence of broken screws. SUMMARY OF BACKGROUND DATA: In clinical practice, single-segment thoracolumbar fractures were then more likely to be treated with SSPF that included pedicle fixation at the level of the fracture (short same-segment fixation, or SSSF). Whether SSSF could really achieve vertebral height recovery, improve the kyphosis, reduce postoperative kyphosis loss, and reduce the incidence of internal fixation failure better than SSPF. METHODS: Patients treated with SSPF or SSSF at our institution during 2006 to 2014 were reviewed. Effects of thoracolumbar fracture reduction, improved kyphosis angle, and maintaining vertebral height were compared between groups. Logistic regression analysis was used to identify factors related to instrumentation breakage and correlation analysis to assess possible relations between loss of correction of the kyphosis angle (LAWAC) and other factors. RESULTS: Altogether, 130 patients were enrolled (53 SSPF, 77 SSSF). SSPF (22F, 31M) group's mean (range) age was 37.7 (16-60) years, and the follow-up was 26.2 (9-120) months. SSSF (27F, 50M) group's mean (range) age was 39.3 (17-61) years, and the follow-up was 23.2 (9-60) months. All patients underwent either internal fixation or screw repair. Immediately postoperatively, restoration after middle vertebral fractures was better in SSSF patients than in SSPF patients (P = 0.003), with no differences in other fracture-related factors (P > 0.05). Only LAWAC was significantly associated with instrumentation breakage (P < 0.05). Also, immediately postoperatively, the anterior/posterior vertebral heights ratio was negatively related to LAWAC. CONCLUSION: Pedicle fixation of the fracture did not obtain better recovery of anterior or posterior vertebral heights nor did it improve AWA restoration. There was no significant difference in LAWAC between groups or in the incidence of broken screws. LAWAC may increase the incidence of broken screws. LEVEL OF EVIDENCE: 4.

[Delayed decompression for cauda equina syndrome secondary to lumbar disc herniation: long-term follow-up results].

OBJECTIVE: To assess the impact of delayed decompression on long-term neurological and bladder function recovery in patients with cauda equina syndrome (CES) secondary to lumbar disc herniation (LDH). METHODS: The clinical data of 35 patients receiving delayed decompression surgery for CES secondary to LDH were reviewed. The bladder empty function, bowel control, sexual ability and neurological functions of the lower limbs were evaluated after the operation, and the urodynamic changes were assessed in 6 patients with urodynamic data before and after the operation. RESULTS: Surgical decompression was performed at 4.1∓3.9 weeks in 12 patients with complete CES and at 5.5∓7.6 weeks in 23 patients with incomplete CES after the onset of symptoms. The patients were followed up for a mean of 43.0∓28.9 months (3-110 months). In the 23 patients with incomplete CES, 19 obtained full recovery, 4 had slight sensory alterations in the saddle area or the lower limbs. In the 12 patients with complete CES, 2 had full recovery, 4 reported slight sensory alterations in the saddle area or the lower limbs (including 2 with occasional constipation); 6 still had sense deficit in the saddle area and difficulties in bladder or bowl emptying, but they all reported significant improvements compared to the condition before operation. Urodynamic analysis in the 6 patients with pre- and postoperative urodynamic data showed increased abdominal pressure when voiding with significantly reduced residual urine in all the 6 patients; 4 patients with abnormal first desire volume before operation reported recovery after the operation. CONCLUSION: Patients with LDH-induced CES who missed the chance of early decompression can still expect favorable functional recovery in the long term. The improvement of bladder function following decompression is probably a result of recovery of bladder sensation and the compensation by increased intra-abdominal pressure. The key strategy to promote bladder function recovery in these patients is to promote the detrusor recovery.

Is duration of preoperative anti-tuberculosis treatment a risk factor for postoperative relapse or non-healing of spinal tuberculosis?

PURPOSE: This study evaluated the relationship between spinal TB postoperative recurrence or non-healing and duration of preoperative anti-TB treatment (ATT). METHODS: From January 2004 to January 2013, patients who underwent surgery for spinal TB and met this study's inclusion criteria were retrospectively reviewed. Observed parameters were age, sex, initial ESR, preoperative ESR, degree of ESR change, initial CRP, preoperative CRP, degree of CRP change, duration of preoperative ATT, surgical approach, presence of internal fixation, location of spinal lesion, number of involved segments, duration of operation, and intraoperative blood loss. The data were analyzed by univariate and multivariate analyses for spinal TB recurrence or non-healing to determine related risk factors. RESULTS: A total of 223 patients met the inclusion criteria. There were 84 female and 139 male patients with a mean age of 42.2 years (range 2-85 years). The follow-up period was 18-72 months (average 28.7 months). Among 223 patients observed, 23 patients had postoperative relapse or non-healing (10.3 %) during the follow-up period. Statistical analysis indicated that the location of a spinal lesion was significantly associated with postoperative relapse or non-healing. Risk of postoperative relapse or non-healing in thoracolumbar TB was 2.524-fold (95 % CI 1.026-6.580) that of lumbosacral TB. CONCLUSIONS: Duration of preoperative ATT may not be a risk factor for postoperative recurrence or non-healing of spinal TB. Junctional zones such as the lumbosacral and thoracolumbar junction have a higher recurrence rate than non junctional.

Clinical outcomes after decompressive laminectomy for symptomatic ossification of ligamentum flavum at the thoracic spine.

Ossification of the ligamentum flavum (OLF) is a rare disease that causes acquired thoracic spinal canal stenosis and thoracic myelopathy. The aim of this study was to investigate clinical outcomes of symptomatic thoracic OLF treated using posterior decompressive laminectomy. We retrospectively analyzed the medical records of 22 patients who underwent posterior decompressive laminectomy for symptomatic thoracic OLF. The surgical results were evaluated using the modified Japanese Orthopaedic Association (JOA) scoring system and Hirabayashi recovery rate. The intensity of pain was evaluated using a visual analog scale (VAS). The mean duration of follow-up was 35.6months. The mean JOA score was significantly improved at final follow-up (9.18±standard deviation of 1.53 points [range, 6-11 points]) compared with before surgery (5.64±2.04 points [range, 3-9 points]) (P<0.001). The mean Hirabayashi recovery rate was 65.49% (range, 20-100%). Recovery outcomes were excellent in nine patients, good in eight patients, fair in four patients and unchanged in one patient. No patient was classified as deteriorated. The VAS scores were 2.82±3.08 before surgery and 0.59±1.05 at final follow-up (P=0.001). Surgical complications, which resolved after appropriate and prompt treatment, included dural tear in five patients, cerebrospinal fluid leakage in one patient, immediate postoperative neurologic deterioration in one patient, epidural hematoma in one patient, and wound infection in one patient. Our findings suggest that posterior decompressive laminectomy is an effective treatment for symptomatic thoracic OLF and provides satisfactory clinical improvement, but surgery for thoracic OLF is associated with a relatively high incidence of complications.

[Establishment of a rabbit model of scoliosis induced by asymmetric load using springs].

OBJECTIVE: To establish rabbit model of scoliosis induced with stable asymmetric lumbar loads. METHODS: Scoliosis was induced in 10 two-month-old New Zealand rabbits using 316L stainless steel springs placed between the unilateral transverse processes of L2 and L5. Serial radiographs were documented before and at 1, 4, 8, 9 and 12 weeks after the operation. At weeks, the rabbits were randomly divided into SR group (n=5) with the spring removed and SK group (n=5) without spring removal. RESULTS: All the rabbits survived the experiment with Cobb angle all greater than 10 degree at the end of the experiment. Significant changes were found in the Cobb angles and kyphotic angles at 1, 4 and 8 weeks after the operation (P<0.05). At 8 weeks, the Cobb angle, the kyphotic angle and the length of the spring were similar between SR and SK groups (P>0.05), and in the 4 weeks following spring removal in SR group, the Cobb angle and the kyphosis decreased significantly compared with those in SK group (P<0.05). Micro-CT showed that the BV/TV of the concave side was greater than that of the convex side. The length of the spring did not show obvious changes during the experiment (P>0.05). CONCLUSIONS: Asymmetric lumbar loading is a convenient, time-saving, and highly reproducible approach for establishing rabbit models of scoliosis.

Risk factors of new symptomatic vertebral compression fractures in osteoporotic patients undergone percutaneous vertebroplasty.

PURPOSE: This study evaluated the risk factors of new vertebral compression fractures (VCFs) following percutaneous vertebroplasty (PVP). METHODS: From June 2005 to January 2011, patients with osteoporotic VCFs (OVCFs) who were treated with PVP and met this study's inclusion criteria were retrospectively reviewed. Observed parameters were age, sex, bone mineral density, body mass index, amount of bone cement, cement leakage into the disk, preoperative kyphosis, preoperative degree of anterior vertebral compression, preoperative degree of middle vertebral compression, kyphosis correction, anterior vertebral height restoration, middle vertebral height restoration, and number of initial symptomatic fractures (levels treated). The data were analyzed by univariate and multivariate analysis for the emergence of new fractures after PVP to determine related risk factors. RESULTS: A total of 182 patients met the inclusion criteria. There were 155 female and 27 male patients with a mean age of 69.7 years (range 49-91 years). The follow-up period was 24-50 months (average 26.4 months). A total of 294 VCFs among 182 patients were observed, 28 new VCFs occurred in 21 patients (21/182, 11.5 %) during the follow-up period. Statistical analysis indicated that higher BMI (P = 0.004) and a greater number of initial symptomatic fractures (P = 0.017) were significantly associated with new VCFs after PVP. It is the most obvious that the risk of new fractures increased 2.518-fold (95 % CI 1.176-5.395), when the number of initial VCFs increased by one level. CONCLUSIONS: The incidence of new symptomatic VCFs after PVP was higher in osteoporotic patients with initial multiple-level fractures.

[Perioperative complications of single-stage surgical management for spinal tuberculosis].

OBJECTIVE: To analyze the causes of perioperative complications of single-stage surgical management for spinal tuberculosis. METHODS: One hundred and twenty patients with thoracic, lumbar and lumbosacral spinal tuberculosis were treated by single-stage surgical management from January 1997 to January 2006 in our unit, including seventy-five males and forty-five females. The mean age was 34.5 (range 17 to 68) years old. The lesion ranged from T(6) to S(1). The anterior procedures of anterior debridement, interbody fusion and anterior fixation were carried out in sixty-five cases, posterior procedures in twenty-six cases, and combined anterior and posterior procedures in twenty-nine cases, respectively. The complications that occurred during surgical procedure and 1 month after operation were recorded. Underlying causes were analysed. RESULTS: There were 10 cases (8.3%) were recorded of mild to severe complications during perioperative period in 120 patients. The complications and underlying causes were as follows: (1) A patient died from liver failure and blood coagulation dysfunction after operation due to inappropriate surgical timing (n = 1), in which case the patient with lumbosacral spinal tuberculosis also suffered from alcoholic liver sclerosis and dysfunction. (2) False diabetes insipidus (n = 1) and deep vein thrombosis of lower limbs (n = 1) occurred as result of surgical trauma. (3) Tear of iliac vein (n = 1) occurred with lumbosacral spinal tuberculosis because of unclear anatomical relationships when anterior debridement was performed. Injury of lumbar nerve roots (n = 3) and hemothorax (n = 1) also occurred due to mispractice of surgical procedures. (4) Paralysis intestinal obstruction and hypokalemia (n = 2) occurred after anterior procedures for lumbar spinal tuberculosis as a result of other reasons. CONCLUSIONS: Improper perioperative care will lead to complications of single-stage surgical procedures for spinal tuberculosis. Emphasis should be put on preoperative evaluation, surgical planning, and postoperative caring for prevention of complications.

[Analysis of the long-term outcome of anterior approach surgery on cervical spondylotic myelopathy].

OBJECTIVE: To investigate the long-term efficacy of anterior approach surgery on cervical spondylotic myelopathy and factors affecting prognosis. METHODS: The data in 116 patients suffered from cervical spondylosis from January 1992 to December 2000 were reviewed, including 80 male cases and 36 female cases, whose age ranged from 36 to 76 years (mean, 51 years). The preoperative course of disease was 2 months to 20 years (mean, 19 months). There were 65 cases (56.0%) with single segments involved, 44 cases (37.9%) with two segments, 7 cases (6.0%) with three segments. Ninety-eight cases were onset slowly, 18 cases with no remote cause and aggravating quickly. Three kinds of surgeries were performed: anterior cervical decompression and autoiliac bone interbody fusion, anterior cervical decompression and fusion with threaded fusion cage, anterior cervical decompression and autoiliac bone interbody fusion with anterior screw-plate system. Improvement in spinal cord function was assessed using the Japanese Orthopaedic Association (JOA) scoring system, the long-term efficacy and influential factors were also analyzed. RESULTS: The mean follow-up time was 7 years and three months (5 - 12 years). The mean preoperative JOA score was 9.34 +/- 1.81. The mean postoperative JOA score was 10.35 +/- 1.85. At the final follow-up, the JOA score was 14.09 +/- 1.90 and the recovery rate was 63.2%. Among the total patients, 27 cases were excellent, 47 cases were fine, 23 cases were good, 19 cases were poor, the fineness rate was 63.8%. The long-term efficacy of anterior approach surgery has close correlations with time of course, age of onset, preoperative spinal cord function and the number of affected segments, but has no correlations with modes of fusion and internal fixation. CONCLUSIONS: The patients will be attentively observed while having a definite diagnosis of cervical spondylotic myelopathy. The good long-term results will be obtained after early anterior cervical decompression and fusion.

[The selection of the surgical approach in the management of fracture and dislocation of lower cervical spine combined spinal cord injury].

OBJECTIVE: To investigate how to select an appropriate surgical approach in the management of fracture and dislocation of lower cervical spine combined spinal cord injury. METHODS: The clinical data of 54 patients of lower cervical spine fracture and dislocation were retrospectively analyzed. There were 29 cases with vertebral body compressive fracture and dislocation, 7 cases with vertebral body bursting fracture and dislocation, 3 cases with unilateral facet dislocation, 15 cases with bilateral facet dislocation. All cases were associated with spinal cord injury. According to American Spinal Injury Association (ASIA) grades, 21 cases were in A grade, 5 cases in B grade, 22 cases in C grade and 6 cases in D grade. All patients had surgical reduction, decompression, stabilization and fusion, 43 cases in anterior approach and 11 cases in posterior approach. RESULTS: All patients were followed up in 12 to 36 months, the mean follow-up time was 18 months. There were no great vessels, trachea, esophagus or spinal cord iatrogenic injury. There were no pull-out and breakage of screws or plates. Fusion was achieved in all patients at an average of 12 weeks postoperatively. There were no pseudarthrosis or bone nonunion. Of all the patients, 96.3% were acquired completely reduction and the normal intervertebral height and lordosis were maintained. Patients with complete spinal cord had no neurologic recovery, but they felt relief from upper limb pain or numb. Incomplete spinal cord lesions improved on average 1-2 Frankel grade after surgery. CONCLUSIONS: For lower cervical spine fracture and dislocation, an ideal anatomy reduction can be obtained with either anterior or posterior approach surgery. It is important to select a suitable surgical approach according to different types of cervical fracture and dislocation.

Effect of nitric oxide synthase inhibitor on proteoglycan metabolism in repaired articular cartilage in rabbits.

OBJECTIVE: To study the effect of nitric oxide synthase inhibitor, S-methyl thiocarbamate (SMT), on proteoglycan metabolism in repaired articular cartilage in rabbits. METHODS: Twenty-four male New Zealand white rabbits, aged 8 months and weighing 2.5 kg+/-0.2 kg, were used in this study. Cartilage defects in full thickness were created on the intercondylar articular surface of bilateral femurs of all the rabbits. Then the rabbits were randomly divided into 3 groups (n=8 in each group). The defects in one group were filled with fibrin glue impregnated with recombinant human bone morphogenetic protein-2 (rhBMP-2, BMP group), in one group with fibrin glue impregnated with rhBMP-2 and hypodermic injection with SMT (SMT group) and in the other group with nothing (control group). All the animals were killed at one year postoperatively. The tissue sections were stained with safranine O-fast green and analyzed by Quantiment 500 system to determine the content of glycosaminoglycan through measuring the percentage of safranine O-stained area, the thickness of cartilages and the mean gray scale (average stain intensity). Radiolabelled sodium sulphate (Na(2)(35)SO(4)) was used to assess the proteoglycan synthesis. RESULTS: At one year postoperatively, the percentage of safranine O-stained area, the mean gray scale and the cartilage thickness of the repaired tissues in SMT group were significantly higher than those of BMP group (P<0.01) and the control group (P<0.05). Result of incorporation of Na(2)(35)SO(4) showed that the proteoglycan synthesis in SMT group was higher than those of BMP group and the control group (P<0.01). CONCLUSIONS: SMT, a nitric oxide synthase inhibitor, can significantly increase the content of glycosaminoglycan and proteoglycan synthesis, and computer-based image analysis is a reliable method for evaluating proteoglycan metabolism.

[Observation of the biological behavior of in vitro cultured immortalized chondrocytes induced by SV40LTAg gene transfection].

OBJECTIVE: To investigate the biological characteristics of immortalized chondrocytes cultured in vitro. METHODS: Primary chondrocytes were immortalized with SV40LTAg gene transfection and grown in monolayer culture. The biological characteristics of the cells were defined in terms of cell morphology and proliferative capacity observed under inverted microscope. GAG synthesis was assessed with toluidine blue and safranine O staining and type-II collagen levels by immunohistochemistry. RESULTS: After 50 passages, the immortalized chondrocytes appeared polygonal or triangular with still vigorous proliferative capacity in monolayer culture and positivity for GAG and collagen type II as characteristic of chondrocytes. CONCLUSION: The immortalized chondrocytes cultured in vitro can maintain their phenotype in a long term.

[Treatment of spondylolysis and spondylolisthesis with posterior STB thoracolumbar transpedicular screw-plate spine fixation system].

OBJECTIVE: To observe the clinical effect of a self-designed posterior STB thoracolumbar transpedicular screw-plate system in the treatment of spondylolysis and spondylolisthesis. METHODS: This STB screw-plate system is developed with titanium alloy (TC4, Ti6Al4V). During December, 1999 and January, 2001, this system was applied in 51 cases, including lumbar spondylolysis and spondylolisthesis (36 cases), degenerative lumbar instability (15 cases). The patients were aged 22 - 78 years, mean age: 47.5 - years; among them there were 14 male cases, 37 female cases; There were 15 cases degenerative spondylolisthesis with grade I-II slip, 36 cases of spondylolysis and spondylolisthesis, including 34 cases with grade I-II slips and 2 cases with grade III slips; single level of 33 cases, two levels 3 cases. Decompression was performed for the 43 cases with interbody fusion using iliac crest or bilateral-lateral fusion using demineralized bone matrix and 8 cases were fixed with demineralized bone matrix fusion without decompression. RESULTS: All the operations heeded about 60 - 120 minutes, and during the operations bleeding amounts were 200 - 500 ml. The cases completely recovered to work or normal action after 3 months of surgeries. 46 of all cases were achieved to satisfactorily reduction and clinical effect, 5 cases of grade II-III remained incomplete reduction (grade I slip). CONCLUSION: This STB system has advantages of biomechanical stability and reduction capability and its effect in clinical application is undoubtedly positive.

[One-stage surgical management for spinal tuberculosis].

OBJECTIVE: To evaluate the clinical efficacy of one-stage surgical management for spinal tuberculosis. METHODS: Fifty-seven patients with thoracic, thoracolumbar and lumbar spinal tuberculosis were treated surgically by a single stage procedure from Jan 1996 to Jan 2001, including anterior resection, interbody outografting and anterior instrumentation in 35 cases, posterior debridement and posterior instrumentation in 16 cases, and posterior instrumentation and anterior resection plus interbody autografting in 6 cases. Titanium-alloy spinal implants were used in 38 cases and stainless steel implants in other 19 cases. Except for three patients, other 54 patients were followed up for one to five years (mean 2.2 years). RESULTS: All these patients had their incision healed by first intention without chronic infection or sinus formation, and no recurrence of spinal tuberculosis was noted in any patient during the follow-up period. Kyphosis correction were achieved by 21.6 degrees on the average postoperatively. There was a mild loss (2 degrees - 4 degrees) of kyphosis correction during follow-up period. Spinal solid fusion at the interface between the graft and adjacent vertebral bodies was shown radiologically in 3.8 months on the average. CONCLUSION: One-stage surgical management has more advantages in that it can completes all the aspects of surgical treatment for spinal tuberculosis. Anterior or posterior instrumentation with titanium-alloy or stainless steel spinal implants is safe, The selection of one-stage surgical procedure should be planed individually.

[Decompression and internal fixation in the treatment of thoracolumbar spine and spinal cord injury: report of 166 cases].

OBJECTIVE: To evaluate the therapeutic effect of several internal fixation methods in the surgical treatment of thoracolumbar spine and spinal cord injury (SSI-TL). METHODS: In the 166 SSI-TL cases included in this retrospective analysis, 37 had vertebral body burst fracture, 109 had vertebral body compression fracture (with compression to a degree over 50%),14 had vertebral body fracture and dislocation and 6 had multilevel vertebral fractures or jumping fracture. In view of the spinal cord injury 59 belonged to Frankel grade A, 46 grade B, 42 grade C and 19 grade D. Posterior decompression, reduction and internal fixation were performed in 122 patients and the other 44 underwent anterior decompression, reduction and ilium bone grafting. RESULTS: Follow-up study for 3 to 18 month was conducted in 123 cases, in which RF screws cracking occurred in 4 cases, Harrington upper hook dislocation in 5 cases and Harrington rod cracking in 6, while the rest cases were free of theses incidents. In terms of the function recovery of the spinal cord, 88 cases showed improvement of the spinal cord and cauda equina of 1 to 3 Frankel grades, leaving only 35 lingering in grade A. CONCLUSION: Decompression should be performed at early stages of SSI-TL, and employment of various internal fixation instrument helps maintain and enhance spinal stability, preventing secondary lesion of the spinal cord and promoting the function recovery of the injured spinal cord.