Emre Acaroglu

Short-segment pedicle instrumentation of thoracolumbar burst fractures: does transpedicular intracorporeal grafting prevent early failure?

Study Design. A prospective, randomized study comparing two treatment methods for thoracolumbar burst fractures: short-segment instrumentation with transpedicular grafting and the same procedure without transpedicular grafting. Objective. To evaluate the efficacy of transpedicular grafting in preventing failure of short-segment fixation for the treatment of thoracolumbar burst fractures. Summary of Background Data. Short-segment pedicle instrumentation for thoracolumbar burst fractures is known to fail early because of the absence of anterior support. Additional transpedicular grafting has been offered as an alternative to prevent this failure. However, there is controversy about the results of transpedicular grafting. Methods. Twenty patients with thoracolumbar burst fractures were included in the study. The inclusion criterion was the presence of fractures through the T11–L3 vertebrae without neurologic compromise. The patients were randomized by a simple method into two groups. Group 1 patients were treated using short-segment instrumentation with transpedicular grafting (TPG) (n = 10), and Group 2 patients were treated by short-segment fixation alone (NTPG) (n = 10). Clinical (Likert’s questionnaire) and radiologic (sagittal index, percentage of anterior body height compression, and local kyphosis) outcomes were analyzed. Results. The two groups were similar in age, follow-up period, and severity of the deformity and fracture. The postoperative and follow-up sagittal index, percentage of anterior body height compression, and average correction loss in local kyphosis in both groups were not significantly different. The failure rate, defined as an increase of 10° or more in local kyphosis and/or screw breakage, was also not significantly different (TPG = 50%, NTPG = 40%, P = 0.99). Conclusions. Short-segment transpedicular instrumentation of thoracolumbar burst fractures is associated with a high rate of failure that cannot be decreased by additional transpedicular intracorporeal grafting.

Constructs Incorporating Intralaminar C2 Screws Provide Rigid Stability for Atlantoaxial Fixation

Study Design. An in vitro biomechanical study of C1–C2 posterior fusion techniques using a cadaveric model. Objectives. To investigate the acute stability afforded across the atlantoaxial segment by a novel technique that uses intralaminar screws in C2, and to compare these results to the stability obtained using a C2 pedicle fixation technique. Summary of Background Data. There are numerous techniques available for rigidly coupling C1 and C2. It has been shown that screw techniques provide higher acute stability than wiring practices. However, many of these methods that use screw fixation in C2 can be technically difficult, especially in cases in which there is an aberrant vertebral artery course or if the C2 pedicle is not large enough to accommodate the instrumentation. A novel technique that uses intralaminar screws in C2 with C1 pedicle screws and bilateral longitudinal rods has been recently developed in an effort to overcome many of these issues. To date, there are no published reports as to whether this new technique provides equivalent (or better) fixation to the currently accepted methods. Methods. Six fresh-frozen human cadaveric cervical spines (C0–C4) were used in this study. Specimens were tested in their intact condition after destabilization via odontoidectomy, and after implantation of 3 different fixation constructs: (1) the Harms technique, 2 pedicle screws in C2, (2) a single C2 pedicle screw and a single C2 intralaminar screw, and (3) a construct having bilateral intralaminar C2 screws. Pure moment loading in flexion/extension, lateral bending, and axial rotation was applied to the occiput. Subsequent relative intervertebral rotations were determined using a 3 camera system. Range of motion for the intact, destabilized, and 3 fixation scenarios was determined, and statistical analysis was performed using one-way analysis of variance Fisher least-significant-difference post hoc test for multiple comparisons. Results. The data indicate that odontoidectomy significantly increased C1–C2 motion in flexion/extension and lateral bending. All 3 fixation techniques significantly reduced motion compared to the intact and destabilized cases. There were no statistically significant differences between the C2 intralaminar and pedicle screw techniques. Conclusions. The results clearly indicate the potential of the intralaminar screw technique to provide stability that is equivalent to methods currently used. Given the serious complications that can follow vertebral artery injury and the decreased likelihood of injury by avoiding placement of C2 pedicle screw(s) and C1–C2 transarticular screw(s), strong consideration should be given to using a construct that incorporates C2 intralaminar screw(s).

Measurement of vertebral rotation in standing versus supine position in adolescent idiopathic scoliosis

Thirty-three structural curves of 25 patients with adolescent idiopathic scoliosis were evaluated using computed tomography (CT) scans and plain radiography. The average Cobb angle on standing radiographs was 55.72° and was observed to be corrected spontaneously to 39.42° while the patients were in supine position (29.78% correction). Average apical rotation according to Perdriolle was 22.75° on standing radiographs and 16.78° on supine scanograms. The average rotation according to Aaro and Dahlborn on CT scans was 16.48°. Radiographic measurements were significantly different from axial CT slice or scanogram measurements (p = 0.000), but the two latter measurements, both obtained in the supine position, did not appear to be different (p = 0.495). Deformities on the transverse plane as well as on the coronal plane are influenced by patient positioning. If the patient lies supine, the scoliosis curve corrects spontaneously to some degree on both planes. Measurements obtained from the scanograms by the Perdriolle method in the supine position are very similar to those obtained by CT. Perdriolles is a simple, convenient, and reliable method to measure rotation on standing radiograms.

Biomechanical Comparison of Posterior Lumbar Interbody Fusion and Transforaminal Lumbar Interbody Fusion Performed at 1 and 2 Levels

Study Design. Biomechanical laboratory study of human cadaveric spines. Objective. To determine the difference in acute stability between posterior lumbar interbody fusion (PLIF) and transforaminal lumbar interbody fusion (TLIF) performed at 1 and 2 levels with and without posterior fixation. Summary of Background Data. Circumferential spinal fusion with both an interbody graft and posterior pedicle screw-rod construct has been advocated to decrease pseudarthrosis rates. Both PLIF and TLIF theoretically allow for 3-column fixation and fusion. Methods. Specimens underwent either PLIF or TLIF at L2–L3 (single-level) and L3–L4 (2-level), both with and without pedicle screw instrumentation. During TLIF, an interbody allograft was placed in the anterior or middle column. Nondestructive, nonconstraining pure moment loading was applied to each specimen. Results. There were no significant differences in the range of motion after either PLIF or TLIF at 1 level. The addition of pedicle screws tended more strongly to increase rigidity after 1-level PLIF compared to TLIF. Position of the TLIF graft did not affect stability. The addition of pedicle screws to a 2-level construct significantly reduced all motions tested. Conclusions. Based on our findings, posterior fixation with a pedicle screw-rod construct is suggested for 1-level PLIF and TLIF, and is necessary to achieve stability after interbody fusion across 2 levels using either technique.

Anterior radical debridement and anterior instrumentation in tuberculosis spondylitis.

Abstract. The conventional procedure in the treatment of vertebral tuberculosis is drainage of the abscess, curettage of the devitalized vertebra and application of an antituberculous chemotherapy regimen. Posterior instrumentation results are encouraging in the prevention or treatment of late kyphosis; however, a second-stage operation is needed. Recently, posterolateral or transpedicular drainage without anterior drainage or posterior instrumentation following anterior drainage in the same session has become the preferred treatment, in order that kyphotic deformity can be avoided. Information on the use of anterior instrumentation along with radical debridement and fusion is scarce. This study reports on the surgical results of 63 patients with Potts disease who underwent anterior radical debridement with anterior fusion and anterior instrumentation (23 patients with Z-plate and 40 patients with CDH system). Average age at the time of operation was 46.8±13.4 years. Average duration of follow-up was 50.9±12.9 months. Local kyphosis was measured preoperatively, postoperatively and at the last follow-up visit as the angle between the upper and lower end plates of the collapsed vertebrae. Vertebral collapse, destruction, cold abscess, and canal compromise were assessed on magnetic resonance (MR) images. It was observed that the addition of anterior instrumentation increased the rate of correction of the kyphotic deformity (79.7±20.1%), and was effective in maintaining it, with an average loss of 1.1°±1.7°. Of the 25 patients (39.7%) with neurological symptoms, 20 (80%) had full and 4 (16%) partial recoveries. There were very few intraoperative and postoperative complications (major vessel complication: 3.2%; secondary non-specific infection: 3.2%). Disease reactivation was not seen with the employment of an aggressive chemotherapy regimen. It was concluded that anterior instrumentation is a safe and effective method in the treatment of tuberculosis spondylitis.

The effect of transpedicular intracorporeal grafting in the treatment of thoracolumbar burst fractures on canal remodeling.

Abstract. Short-segment posterior instrumentation for the treatment of thoracolumbar burst fractures has been reported with a high rate of failure. Transpedicular intracorporeal grafting in combination with short-segment instrumentation has been offered as an alternative to prevent failure. However, concern still remains about the potential complication of further canal narrowing or failure of remodeling with this technique. The purpose of this prospective, randomized, controlled study is to evaluate the effect of transpedicular intracorporeal grafting on spinal canal restoration and remodeling in a group of patients treated with short-segment instrumentation for thoracolumbar burst fractures. Twenty-one patients with thoracolumbar burst fractures were randomised into transpedicular grafting (TPG) (n=11) and non- transpedicular grafting (NTPG) (n=10) groups, and were prospectively followed for an average of 50 months (range 25–85 months). Groups were similar in age, type of fracture, load sharing classification and kyphotic deformity. Preoperative, postoperative and follow-up computed tomographic (CT) images through the level of pedicles were obtained, corrected for differences in magnification, and digitized. Areas of the spinal canals were measured and normalized by the estimated area at that level (average of adjacent levels). Average kyphosis was 19.7°±6.2° at presentation, was corrected to 1.9°±4.9° by operation, but was found to have deteriorated to 9.1°±6.4° at final follow-up. There were no differences between groups regarding the evolution of sagittal deformity. Spinal canal narrowing was 38.5±18.2% at presentation, 22.1±19.8% postoperatively, and it further improved to –2.5±16.7% at follow-up, similar for both groups. Our results demonstrate that transpedicular intracorporeal grafting in the treatment of burst fractures does not have a detectable effect on the rate of reconstruction of the canal area or on remodeling. Spinal canal remodeling was observed to occur in all patients regardless of grafting.

Atlantoaxial rotatory fixation-subluxation revisited: a computed tomographic analysis of acute torticollis in pediatric patients.

Study Design. Cross-sectional clinical and radiologic study with a normal control group. Objectives. To compare the range of motion of the atlantoaxial joint in patients with acute torticollis with those of normals as measured from computed tomography scans, to look for the existence of atlantoaxial rotatory fixation in any position (subluxation or normal range of motion) in this group of patients, and to clarify the definition of atlantoaxial rotatory subluxation by measuring the atlantodental interval and analyzing the location of the center of rotation in patients as well as normal controls. Summary of Background Data. Although acute acquired torticollis is usually termed atlantoaxial rotatory subluxation or atlantoaxial rotatory fixation, the radiologic definition of these conditions is not clear. Patients and Methods. Thirty-three consecutive pediatric patients (average age 8.5 years, range 2–18 years) with acute acquired torticollis were analyzed. All were neurologically intact. Anteroposterior and lateral radiographs were obtained in all atlantoaxial computed tomography scans in 31 patients (dynamic in 23 and static in 8). Twelve age-matched patients with normal cervical spines were also analyzed with dynamic computed tomography as normal controls. Atlantoaxial rotatory subluxation, atlantoaxial angle, center of rotation, and presence of atlantoaxial rotatory fixation were analyzed in each computed tomography. All patients were treated conservatively. Eight had control dynamic computed tomography scans at the end of the treatment. Results. All patients had atlantoaxial rotatory subluxation ≤3 mm. On dynamic computed tomography, the range of atlantoaxial rotation was 30.4° (range 11–54°) toward deformity and 28.3° (range 18–54°) away from deformity (P = 0.333). Atlantoaxial rotatory fixation was not noted in any of the patients. The same measurement for the normal control group was 28° (range 5–41°) (P = 0.770). Of the eight patients with repeat control computed tomography, the atlantoaxial rotatory subluxation was 26° before and 29° after treatment (P = 0.691 to right and P = 0.199 to left). The center of rotation was within dens in 15 of 19 patients, outside dens in 2 of 19, and undetectable in 2 of 19. In the control group, it was within dens in 8 of 11, outside dens in 2 of 11, and undetectable in 1 of 11. All patients were symptom free at the end of the conservative treatment. Conclusion. We could not demonstrate the presence of atlantoaxial rotatory subluxation or atlantoaxial rotatory fixation in our series of 33 consecutive pediatric patients with acute torticollis. Our findings suggest that the existence of these phenomena are doubtful, although not associated with acute acquired torticollis. Acute acquired torticollis is not necessarily the sign of a pathologic condition of the atlantoaxial joint. Finally, it is probably not necessary to obtain computed tomography scans (static or dynamic) in this group of patients at the time of presentation.

Course of nonsurgical management of burst fractures with intact posterior ligamentous complex: an MRI study.

Study Design. Prospective study. Objectives. To evaluate the results of nonsurgical management of burst fractures with intact posterior ligamentous complex and to investigate the effect of trauma and/or residual kyphotic deformity on adjacent and next adjacent (neighboring) discs. Summary of Background Data. Conservative treatment based on integrity of posterior ligamentous complex is controversial, probably because of poor evaluation by clinical and indirect radiographic findings. Degenerative changes in the adjacent discs due to trauma and/or residual kyphotic deformity is a common expectation. Material and Methods. Fifteen consecutive patients who were intact neurologically with burst fractures (T11-L2) were treated nonsurgically with the indication based solely on the integrity of posterior ligamentous complex determined by MRI. Correction of deformity and stabilization with a total body cast under sedation were the mainstays of treatment. Patients were mobilized the next day, and casts were removed at the end of the third month follow-up period with no further external stabilization. Local kyphosis angle, sagittal index, and percent of compression of anterior body height were measured on pretreatment, post-treatment, third month, and latest follow-up radiographs. All of the preoperative and latest follow-up MRI studies of the patients were obtained to examine the discs adjacent and next adjacent to the fractured levels. The self-reported perceptions of the patients of function, pain and appearance were analyzed using the Likert Questionnaire. Results. There were eight female and seven male patients with an average age of 28 (range, 15–49) years. Average follow-up period was 31 (range, 24–51) months. Average local kyphosis angle was found to be 16.5° (0–34°) after trauma. It was corrected to 5° (range, 19–25°) and deteriorated to 14.6° (range, 2–25°) at the third month and to 17° (range, 2–29°) at the final follow-up review. There was a similar tendency for both sagittal index and percent anterior body height. The pretreatment MRI analysis revealed changes in the shape of the discs (narrowing or herniation into the body) with no change in the signal intensity of nucleus pulposus in eight of the cranial and four of the caudal adjacent discs. On follow-up MRI, there was only one intact disc with a normal shape cranially. All others had height loss, but only one had complete loss of signal intensity. Caudally, two additional discs had changes in shape without any gross changes in signal intensity of nucleus pulposus, whereas two had changes in signal intensity without change in shape. Only two of the next adjacent discs had changes in shape or signal intensity at the time of injury or at latest follow-up review. Average score of function, pain, and appearance were 3.9 (range, 3–5), 3.7 (range, 2–5), and 3.7 (range, 2–5), respectively, at the latest follow-up review. All patients were back at work in 3.6 (range, 1–9) months on average and all were satisfied with their treatment. Conclusions. The present study revealed that an intact posterior ligamentous complex might not prevent loss of correction gained by nonsurgical management of burst fractures. Significant loss occurs in the first 3 months despite external stabilization. However, the magnitude of residual deformity usually remains close to the initial deformity. Although changes in the shape of adjacent discs occur due to trauma and/or natural course, significant loss in signal intensity of nucleus pulposus is unlikely. Patient outcome seems to be highly satisfactory despite residual deformity.

Effects of deamino-8-d-arginin vasopressin on blood loss and coagulation factors in scoliosis surgery : a double-blind randomized clinical trial

STUDY DESIGN A double-blind, randomized, prospective clinical study was performed to evaluate the efficacy of deamino-8-D-arginin vasopressin in reducing blood loss in major scoliosis surgery. OBJECTIVES To evaluate whether desmopressin has any effect on reducing blood loss in spinal surgery, to identify the probable mechanisms of effectiveness via blood coagulation factors, and to outline any adverse effect associated with the use of deamino-8-D-arginin vasopressin. SUMMARY OF BACKGROUND DATA Scoliosis surgery is known to be associated with major blood loss. Because of major drawbacks of homologous blood transfusion, many alternative methods have been used to counter the blood loss. Only a few studies exist, with controversial results, on the use of deamino-8-D-arginin vasopressin. METHODS The study population included 40 operations on 35 consecutive patients undergoing reconstructive surgery for either idiopathic (n = 26) or congenital (n = 9) scoliosis. Operations were randomized into deamino-8-D-arginin vasopressin (0.3 microgram/kg body weight; maximum, 20 micrograms) (n = 18) or placebo (n = 22) groups and stratified according to the diagnosis and the type of surgery performed (i.e., anterior versus posterior versus anterior and posterior sequential). Parameters of blood loss, serum levels of blood coagulation factors at different time intervals, and urinary output were measured. RESULTS Findings indicated that blood loss per kilogram of body weight, blood loss per surgically treated spinal level, urinary output per kilogram of body weight and serum levels of fibrinogen, von Willebrand factor (vWF) activity, tissue type plasminogen activator activity, and plasminogen activator inhibitor activity were not sensitive to the administration of deamino-8-D-arginin vasopressin at any time interval during surgery or at 24 hours after surgery (P > 0.05). Only factor VIII:C levels exhibited significant elevations at 30 minutes and at 24 hours (P < 0.05). CONCLUSIONS This study could not demonstrate any significant effect of deamino-8-D-arginin vasopressin on the amount of blood loss in a group of patients with idiopathic or congenital scoliosis. Findings indicate that for most of the coagulation factors, any changes in serum levels induced by deamino-8-D-arginin vasopressin were much like those expected from surgery itself. This study also failed to demonstrate any significant effects altering the urinary output that may be attributed to the use of deamino-8-D-arginin vasopressin.

Safety and efficacy of posterior instrumentation for patients with congenital scoliosis and spinal dysraphism.

Objective: Instrumentation and correction of severe congenital scoliosis, particularly in patients with spinal dysraphism, has been reported to cause a high potential rate of neurological compromise after instrumentation. The aim of this study was to evaluate the safety and efficacy of posterior instrumentation and correction of congenital scoliosis with accompanying spinal dysraphism. Level of Evidence: Level IV therapeutic studies. Methods: Retrospective x-ray measurements to analyze the efficacy and the evaluation of hospital charts to document the intraoperative and postoperative complications were performed for a consecutive patient series. Scoliosis Research Society-22 questionnaire was used to analyze the health-related quality of life. Results: Twenty-two patients (18 girls and 4 boys) formed the basis of the study. The average age was 12 years (range, 7-18 years) and the average follow-up period was 3.2 years (range, 2-10 years). The types of spinal dysraphism were diastematomyelia in 20 patients and syringomyelia with tethered cord in 2 patients. Twelve patients had previous surgery and 3 patients had simultaneous surgeries for spinal dysraphism. Posterior instrumentation with/without anterior release and fusion was performed in all patients. Major curve was corrected from an average of 71 degrees to 40 degrees (correction rate, 43.6%). The compensatory curve was corrected from an average of 47 degrees to 25 degrees (correction rate, 46.8%). The average loss of correction at final follow-up was 2.2 degrees for major curve and 3.5 degrees for the compensatory curve. The average scores for the 5 domains of Scoliosis Research Society-22 questionnaire were 3.5 for function, 3.9 for pain, 3.5 for self-image, 3.6 for mental health, 3.9 for satisfaction, and 3.6 for total. Neurological monitoring was conducted by using the wake-up test in all patients. The overall complication rate was 31%, including neurological compromise in 2 patients (9%). Conclusions: Spinal instrumentation was effective for the control of deformity with a relatively higher rate of complications. However, with respect to high complication rate, the ideal solution for managing the congenital cases is still to prevent the progression of the curve with early intervention by using the optimal surgical approach for that particular patient.