Anterior Thoracolumbar Research Articles

Long-term outcomes and complications of isolated anterior thoracolumbar fusion for neuromuscular scoliosis associated with myelomeningocele.

Neuromuscular scoliosis associated with myelomeningocele is a difficult clinical dilemma for the treating surgeon. The traditional surgical treatment consists of a posterior spinal instrumented fusion with or without a combined anterior procedure, but this has been associated with high complication rates, mostly related to deep infection. An anterior thoracolumbar fusion is not able to address the entirety of the deformity in many cases but could potentially avoid the devastating infection risks from the posterior approach by avoiding compromised skin. This study aims to evaluate the long-term outcomes and complications associated with isolated anterior thoracolumbar fusion in this high-risk group. This study is a retrospective analysis of patients with myelomeningocele-associated scoliosis treated with an isolated anterior spinal fusion over a 20-year time period at a single center. Surgical details, demographics, curve characteristics and complications were recorded. Comparisons were made between patients who required revision surgery and those who did not. Sixteen patients were enrolled with an average age of 12.7years at the time of surgery and average follow-up of 5.5years. Patients had on average 7.4 levels fused anteriorly with the most common levels being T10-L4. There were no deep wound infections associated with the anterior surgery. Overall, nine patients (56%) had to be revised posteriorly due to adding-on or junctional deformity at an average of 3.7years after index procedure. Four patients were revised due to proximal adding-on, while 1 was extended distally. Four additional patients were extended both proximally and distally. Of the posterior revisions, 2 patients developed deep wound infections, and both of these were in patients extended distally. Preoperative lumbar lordosis was higher in patients who required distal extension (100 vs. 69 degrees; p = 0.035). Patients undergoing isolated anterior fusion for scoliosis associated with myelomeningocele have low infection rates but often require posterior revision. The majority of patients can avoid the deep infection risk associated with distal posterior surgery at long-term follow-up. IV.

Identifying risks factors in thoracolumbar anterior fusion surgery through predictive analytics in a nationally representative inpatient sample.

Anterior thoracolumbar (TL) surgical approaches provide more direct trajectories compared to posterior approaches. Proper patient selection is key in identifying populations that may benefit from anterior TL fusion. Here, we utilize predictive analytics to identify risk factors in anterior TL fusion in patients with trauma and deformity. In this retrospective cohort study of patients receiving anterior TL fusion (between and including T12/L1), population-based regression models were developed to identify risk factors using the National Readmission Database 2016-2017. Readmissions were analyzed at 30- and 90-day intervals. Risk factors included hypertension, obesity, malnutrition, smoking, alcohol use, long-term opioid use, and frailty. Multivariate regression models were developed to determine the influence of each risk factor on complication rates. A total of 265 and 375 patients were identified for the scoliosis and burst fracture cohorts, respectively. In patients with scoliosis, alcohol use was found to increase the length of stay (LOS) (p = 0.00061) and all-payer inpatient cost following surgery (p = 0.014), and frailty was found to increase the inpatient LOS (p = 0.0045). In patients with burst fractures, malnutrition was found to increase the LOS (p < 0.0001) and all-payer cost (p < 0.0001), obesity was found to increase the all-payer cost (p = 0.012), and frailty was found to increase the all-payer cost (p = 0.031) and LOS (p < 0.0001). Patient-specific risk factors in anterior TL fusion surgery significantly influence complication rates. An understanding of relevant risk factors before surgery may facilitate preoperative patient selection and postoperative patient triage and risk categorization.

Anterior Approach to the Thoracic and Thoracolumbar Spine: A Prospective Study in Our Hospital

Background Data: Anterior approaches to the thoracic and thoracolumbar spine have several advantages including direct access to the lesion, less surgical bleeding, low risk of infection, and shorter segment fixation devices. It provides excellent visualization and access to the anterior thoracic spine, vertebral bodies, intervertebral disks, spinal canal, and nerve roots and may improve neurological outcome. Purpose: To evaluate various outcome parameters of the anterior approach to the thoracolumbar spine of various pathologies. Study Design: Prospective clinical case study. Patients and Methods: Thirty patients were included in this study. Patients with infections, malignancy, and trauma were included, while patients with medical comorbidities, extensive several spinal levels disease, posterior tension band injury and translational or rotational injury, and severe osteopenia or osteoporosis were excluded. The evaluation included the demographic data, clinical features, level of injury, and neurological status of these patients. All patients underwent operation through the anterior thoracolumbar approach. Outcome parameters included preoperative and perioperative data and postoperative ASIA, VAS, SCIM, and ODI. Results: The age of patients was 46.06±12.2 (range, 20–70) years. Twenty patients were males and 10 were females. Most patients were 41–50 and >50 years. Thirteen patients (43%) suffered from traumatic fractures (M:F 3.3:1), 14 (47%) tuberculous spondylodiscitis (M:F 1.8:1), and 3 (10%) metastatic compression fracture. Surgical time was 213.12 and 201.43 minutes in Rt and Lt side approach, respectively, while blood loss was 609.4 and 650 ml in Rt and Lt side approach, respectively. In the whole group, pre- and postoperative sensory ASIA score was 91.53 and 105.8; motor ASIA score was 66.2 and 77.13; VAS was 5.13 and 0.63; SCIM was 30.93 and 76.13; ODI was 74 and 16.53, respectively. Complications included wound infection (N=3), kyphosis (N=3), intraoperative vascular injury (N=2), new neurological deficit (N=2), and myocardial infarction (N=1). Conclusion: Anterolateral approach in thoracic and thoracolumbar pathologies achieves adequate decompression, pathological evaluation for tissue, the possibility for instrumentation, and favorable neurological outcome. The familiarity and experience of the surgeon with the approach will always remain a cornerstone for the success of the procedure. (2020ESJ204)

Surgical Anatomy and Approaches to the Anterior Thoracolumbar Spine Region

We review the surgical anatomy of the thoraco-lumbar spine region located between the eleventh thoracic and the second lumbar vertebrae (T11-L2). Anatomical features of muscular, vascular and neural structures important to surgical approaches are described in details. We also discuss surgical nuances of the transthoracic retroperitoneal and the lateral retropleural approaches. We conclude that anatomical knowledge is important to improve the efficacy and safety of surgical procedures in the thoraco-lumbar spine region.

Selective Anterior Thoracolumbar Fusion in Adolescent Idiopathic Scoliosis: Long-Term Results After 17-Year Follow-Up.

Prospectively updated long-term data and retrospective case series analysis. To report the long-term results of selective anterior instrumented thoracolumbar (ThL) fusion in adolescent idiopathic scoliosis (AIS). The results of anterior selective fusion in AIS have been reported up to 2 and 5 years follow-up. However, there is a lack of evidence of long-term results of this surgical approach. Forty-two consecutive patients with main thoracolumbar/lumbar AIS who had undergone surgery for a selective anterior ThL instrumented fusion with more than 12 years of follow-up met inclusion criteria. Preoperative, postoperative (1-yr), and final updated radiographic parameters were recorded. Final ODI and SRS-22 questionnaires were evaluated. Thirty-five patients were finally recruited (5 were lost and 2 refused). The mean age at surgery was 16.6 years. The mean final follow-up was 17.3 years (12-24 yr).The ThL preoperative Cobb was 49.5° ± 9, obtaining a postoperative correction of 79%±13 and final correction of 72% ± 18. The preoperative thoracic curve (31.4° ± 14.2) obtained a spontaneous postoperative correction to 18.4° ± 11.9, maintained at final follow-up (17.8° ± 10.8). Apical vertebral rotation improved from 25.8° ± 7.8 to 9.2° ± 5.5 and finally to 8° ± 5.2 (P = 0.001). Sagittal parameters (T5-T12 = 27.2° and L1-S1=56.9°) did not change significantly postoperatively nor by final follow-up. Coronal balance improved from 2.4 cm to 1.6 cm postoperatively and 0.8 cm at final follow-up (P = 0.006). The disc angulation below the last instrumented vertebra improved with follow-up from 7.6° to 5.7° (P = 0.012).There were no revision surgeries or infections. One patient showed a symptomatic lower disc degeneration requiring lumbar pain surgery. Final SRS-22 global score was 4.3/5. The final ODI scored 6/100. In the long term, selective anterior thoracolumbar instrumentation with a single solid rod in AIS maintained good corrections on the three planes with no major complications or infections, no revision surgeries, and with satisfactory final functional and clinical outcomes. 4.

Kinematics and load-sharing of an anterior thoracolumbar spinal reconstruction construct with PEEK rods: An in vitro biomechanical study

BackgroundPolyetheretherketone rod constructs provide adequate spinal stability. Kinematics and load sharing of anterior thoracolumbar reconstruction with polyetheretherketone rods under preload remains unknown. MethodsEight human cadaveric specimens (T11-L3) were subjected to a pure moment of 5.0Nm in flexion-extension, lateral bending and axial rotation, and flexion-extension with a compressive preload of 300N. An anterior reconstruction of L1 corpectomy was conducted with a surrogate bone graft and anterior rod constructs (polyetheretherketone or titanium rods). An axial load-cell was built in the surrogate bone graft to measure the compressive force in the graft. Range of motion, neutral zone and compressive force in the graft were compared between constructs. FindingsThe polyetheretherketone rod construct resulted in more motion than the titanium rod construct, particularly in extension (P=0.011) and axial rotation (P=0.001), but less motion than the intact in all directions except in axial rotation. There was no difference in range of motion or neutral zone between constructs in flexion-extension under preload. The polyetheretherketone rod construct kept the graft compressed 52N which was similar to the titanium rod construct (63N), but allowed the graft compressed more under the preload (203N vs. 123N, P=0.003). The compressive forces fluctuated in flexion-extension without preload, but increased in flexion and decreased in extension under preload. InterpretationThe polyetheretherketone rod construct allowed more motion compared to the titanium rod construct, but provided stability in flexion and lateral bending without preload, and flexion and extension under preload. The anterior graft shared higher load under preload, particularly for the polyetheretherketone rod construct. The results of this study suggest that rigidity of rods in the anterior reconstruction affects kinematic behavior and load sharing.

Posterior Vertebral Column Resection: A Salvage for Thoracolumbar Kyphosis after Failed Anterior Instrumented Fusion

Introduction Anterior thoracolumbar spine surgery is typically indicated for restoration of structural stability and /or decompression of neural element secondary to trauma, tumor or infection. But postoperative complications especially kyphosis poses distinct challenges to the spinal surgeon. The aim of this study was to explore the effects of posterior vertebral column resection of thoracolumbar kyphosis after failed anterior instrumented fusion. Material and Methods A retrospective study was conducted of 10 patients of kyphotic deformity with previous failed anterior surgery in our department from October 2005 to December 2009. The indications for revision surgery included pain refractory to conservative treatment, progressive neurological deficit and kyphosis. Anterior removal of the implant and posterior vertebral column resection (PVCR) was performed. Mean operating time, average intraoperative blood loss, kyphosis angle, the visual analog scale (VAS), Oswestry disability index (ODI), bone fusion time and complications were used for clinical assessment in a minimum 18-month follow-up (18 – 60 months). Results The mean age was 38.7 years old (ranging from 24 to 56 years old) and the average kyphosis angle was 54.60 (ranging from 45 0 to 74 0). Mean operating time was 323.5 (range 245 minute to 420 minute) with average intraoperative blood loss of 1189 ml (range 850 ml to 1550 ml). After revision surgery, Kyphosis angle was 4.800 (range3- 70) immediately and 6.80 (range 5 to 90) at the 18 months follow-up and there was good bony fusion in every case. The average time of bony fusion was 6.8 months (range 5–9 months). All patients had satisfied spinal sagittal and coronal balance at the last follow-up. None of our patients experienced implant failure. The average preoperative VAS was 6.2, falling to 2.6 at the 18 months follow-up with significant improvement. None of the patients suffered any surgery-related neurological deterioration and one patient whose neurological status was Frankel Grade C improved to Grade D. The ODI changed form a mean value of 39.8 (rang 31–48) preoperatively to 24.5 (rang 15–29) at the final follow-up. The difference was statistically significant. Complications occurred in four patients (40%); these included three with tearing of the lung and one with a superficial wound infection. Conclusion Despite the technically demanding procedure, anterior removal of the implant and posterior vertebral column resection was a safe and effective revision surgery for patients with prior anterior fusion with rigid post-surgical deformities.

Range of motion after thoracolumbar corpectomy: evaluation of analogous constructs with a novel low-profile anterior dual-rod system and a traditional dual-rod system

An in vitro biomechanical study. To compare the biomechanical stability of traditional and low-profile thorocolumbar anterior instrumentation after a corpectomy with cross-connectors. Dual-rod anterior thoracolumbar lateral plates (ATLP) have been used clinically to stabilize the thorocolumbar spine. The stability of a low-profile dual-rod system (LP DRS) and a traditional dual-rod system (DRS) was compared using a calf spine model. Two groups of seven specimens were tested intact and then in the following order: (1) ATLP with two cross-connectors and spacer; (2) ATLP with one cross-connector and spacer; (3) ATLP with spacer. Data were normalized to intact (100%) and statistical analysis was used to determine between-group significances. Both constructs reduced motion compared to intact in flexion-extension and lateral bending. Axial rotation motion became unstable after the corpectomy and motion was greater than intact, even with two cross-connectors with both systems. Relative to their respective intact groups, LP DRS significantly reduced motion compared to analogous DRS in flexion-extension. The addition of cross-connectors reduced motion in all loading modes. The LP DRS provides 7.5mm of reduced height with similar biomechanical performance. The reduced height may be beneficiary by reduced irritation and impingement on adjacent structures.

Venous Thromboembolism After Spine Surgery

Retrospective cohort study. To measure the rate of postoperative venous thromboembolic events (VTE) after spine decompression and fusion procedures. VTE after spine surgery is a serious complication, but chemoprophylaxis is not without significant risk due to the concern of epidural hematoma. Current literature report widely variable rates of VTE, and have weaknesses in sample size, specificity of diagnosis, and methodological problems with adequate patient follow-up. State-level inpatient, ambulatory surgery, and emergency department administrative databases were used to track patients for clinically significant VTE within 90 days of discharge after a spine procedure. Of 357,926 patients enrolled, one-third underwent spine decompression alone, whereas two-thirds received a spine fusion. The overall rate of VTE was 1.37% (95% CI: 1.33-1.41), but varied widely depending on diagnosis, 1.03% for structural degenerative diagnoses to 10.7% for spine infection. Posterior cervical fusion had a higher rate of VTE than anterior cervical fusion, whereas anterior thoracolumbar and lumbosacral fusions had higher rates than the respective posterior approaches. Additional risk factors included patients receiving long spine fusions and having multiple procedures during the hospitalization. Forty percent of VTEs discovered after discharge were diagnosed at a different hospital. The rate of spine VTE varies widely depending on diagnosis and procedure. It is important to risk-stratify patients who present for spine surgery to identify patients at increased risk who should be monitored for the development of VTE. It is important to know that nearly half of VTEs that occur after discharge are diagnosed at different hospitals, and thus the primary surgeon may be initially unaware of the complication. These results from a large selection of historical patients may provide a tool for estimating patient risk depending on diagnosis and type of procedure. 2.

Comparison of Clinical and Radiologic Results between Expandable Cages and Titanium Mesh Cages for Thoracolumbar Burst Fracture

ObjectiveA thoracolumbar burst fracture is usually unstable and can cause neurological deficits and angular deformity. Patients with unstable thoracolumbar burst fracture usually need surgery for decompression of the spinal canal, correction of the angular deformity, and stabilization of the spinal column. We compared two struts, titanium mesh cages (TMCs) and expandable cages.Methods33 patients, who underwent anterior thoracolumbar reconstruction using either TMCs (n=16) or expandable cages (n=17) between June 2000 and September 2011 were included in this study. Clinical outcome was measured by visual analogue scale (VAS), American Spinal Injury Association (ASIA) scale and Low Back Outcome Score (LBOS) for functional neurological evaluation. The Cobb angle, body height of the fractured vertebra, the operation time and amount of intra-operative bleeding were measured in both groups.ResultsIn the expandable cage group, operation time and amount of intraoperative blood loss were lower than that in the TMC group. The mean VAS scores and LBOS in both groups were improved, but no significant difference. Cobb angle was corrected higher than that in expandable cage group from postoperative to the last follow-up. The change in Cobb angles between preoperative, postoperative, and the last follow-up did not show any significant difference. There was no difference in the subsidence of anterior body height between both groups.ConclusionThere was no significant difference in the change in Cobb angles with an inter-group comparison, the expandable cage group showed better results in loss of kyphosis correction, operation time, and amount of intraoperative blood loss.

Anterior approach for surgery of thoracolumbar spine: surgical outcomes of series of one self-trained neurosurgeon

Summary Purpose Most neurosurgeons in Taiwan are not trained formally to perform anterior approaches for thoracolumbar corpectomies in the treatment of thoracolumbar lesions during their residencies. Often, such procedures are conducted with the assistance of “access surgeons”. Materials and methods Prior to performing anterior thoracolumbar corpectomies in clinical cases, one senior neurosurgeon, who was not trained in the anterior approaches, acquired the relevant skills from cooperating access surgeons, by attending a workshop, and by practicing on cadavers. Between December 2006 and March 2011, 18 consecutive patients underwent surgeries involving the anterior approach to thoracolumbar lesions. Patients operated on by the self-trained neurosurgeon were included in Group 1, and those operated on by neurosurgeons assisted by access surgeons were included in Group 2. Operative time, blood loss, complications, and neurologic outcomes were compared between the two groups. Results Group 1 consisted of 10 patients (4 men), with a mean age of 62.5 years, and Group 2 of eight patients (5 men), with a mean age of 58.3 years. The median follow-up periods for both groups were 15.5 and 17 months, respectively. Operative time, blood loss, rate of complications, and neurologic outcomes were comparable between the two groups. Conclusion Through observation, by attending workshops, and by practicing the anterior approach on cadavers, the self-trained neurosurgeon became competent in the anterior thoracolumbar corpectomy and achieved comparable results to surgeons who were assisted by access surgeons in terms of operative time, blood loss, complications, and neurologic outcomes.

Predictability of spontaneous thoracic curve correction after anterior thoracolumbar correction and fusion in adolescent idiopathic scoliosis. A retrospective study on a consecutive series of 29 patients with a minimum follow-up of 2 years

Background contextAccording to the Lenke classification, a Type 5 adolescent idiopathic scoliosis can be surgically treated with selective anterior thoracolumbar or lumbar fusion. PurposeThis study aims to predict the spontaneous correction of the unfused thoracic curve after anterior thoracolumbar fusion and to study whether age is of influence on this predictability. Study designRetrospective study on a consecutive series of patients. Patient sampleOf a consecutive series of 38 patients with idiopathic thoracolumbar scoliosis, Lenke type 5, 29 patients were included in the study. All patients were treated with anterior spinal fusion and instrumentation. A minimum follow-up of 2 years was available for all patients (mean, 4 years; range, 2–17 years). To investigate the influence of age on the outcome, we divided the group into two subgroups: an adolescent (n=13) and an adult age group (n=16). The mean age in the adolescent group was 17 (range, 13–21 years) and 38 years (range, 22–54 years) in the adult group. Outcome measuresPhysiological measures include coronal Cobb angle, apical vertebral translation (AVT) and apical vertebral rotation (AVR), shoulder tilt, trunk shift, L4 tilt, and pelvic tilt. Relative corrections were computed for the thoracolumbar and thoracic curves in each patient using the following formula: (preoperative curve−postoperative curve)/preoperative curve×100 (%). The correlation coefficient between the relative (%) corrections of the thoracic and thoracolumbar curves was calculated for the whole group as for the two age subgroups. MethodsFor radiographic evaluation, we used standing anteroposterior and lateral projections of the thoracolumbar spine to determine Cobb angle, AVT and AVR, and coronal balance. ResultsBoth the thoracolumbar and thoracic curves in the whole group improved after surgery (45% and 19%, respectively, p<.01). In the adolescent age group, a significant correlation between the relative (%) correction of the thoracolumbar curve and the relative (%) correction of the thoracic curve was found (R=0.704; p=.01) and between age and relative (%) correction of the thoracic curve (R=−0.805; p<.01). ConclusionsThese results show that the spontaneous correction of the thoracic curve is a reflection of the thoracolumbar curve correction in adolescent thoracolumbar idiopathic scoliosis. Moreover, the predictability of the thoracic curve correction in the individual patient seems to decrease with increasing age of the patient.

Biomechanical Study Comparing a New Combined Rod-plate System With Conventional Dual-rod and Plate Systems

Most anterior spinal instrumentation systems are designed as either a plate or dual-rod system and have corresponding limitations. Dual-rod designs may offer greater adjustability; however, this system also maintains a high profile and lacks a locking design. Plate systems are designed to be stiffer, but the fixed configuration is not adaptable to the variety of vertebral body shapes. The authors designed a new combined rod-plate system (D-rod) to overcome these limitations and compared its biomechanical performance with the conventional dual-rod and plate system. Eighteen pig spinal specimens were divided into 3 groups (6 per group). An L1 corpectomy was performed and fixed with the D-rod (group A; n=6), Z-plate (Sofamor Danek, Memphis, Tennessee) (group B; n=6), or Ventrofix (Synthes, Paoli, Pennsylvania) (group C; n=6) system. T13-L2 range of motion was measured with a 6 degrees of freedom (ie, flexion-extension, lateral bending, and axial rotation) spine simulator under pure moments of 6.0 Nm. The D-rod and Ventrofix specimens were significantly stiffer than the Z-plate specimens (P<.05) based on results obtained from lateral bending and flexion-extension tests. The D-rod and Z-plate specimens were significantly stiffer than the Ventrofix specimens (P<.05) in axial rotation. The D-rod combines the advantages of the plate and dual-rod systems, where the anterior rod exhibits the design of a low-profile locking plate, enhanced stability, and decreased interference of the surrounding vasculature. The posterior rods function in compression and distraction, and the dual-rod system offers greater adjustability and control over screw placement. The results indicate that it may provide adequate stability for anterior thoracolumbar reconstruction.

Risk factors of thoracic curve decompensation after anterior selective fusion in adolescent idiopathic scoliosis with major thoracolumbar or lumbar curve

To investigate the incidence of thoracic curve decompensation or proximal adding-on phenomenon after anterior selective fusion of thoracolumbar or lumbar curve in Lenke type 5 adolescent idiopathic scoliosis (AIS), and to identify its risk factors. From June 2001 to December 2008, 130 Lenke type 5 AIS patients with a Cobb angle of 40° - 73° treated with anterior selective thoracolumbar or lumbar fusion, and with a minimum 2-year postoperative regular follow-up were recruited in this study. The average age, Cobb angle and Risser sign of all patients was 14.8 ± 1.6 years, 46° ± 6° of major thoracolumbar or lumbar curve (TL or L), 25° ± 7° of proximal thoracic curve and 0-5, respectively. The patients were grouped according to the relationship between the upper instrumented vertebrae (UIV) and the upper end vertebrae (UEV), the patients' Risser sign and the relationship between UIV and C(7) plumb line (C(7)PL). The radiographic data of the patients were compared between patients with and without proximal adding-on by using t test, and the incidence of proximal adding-on was analyzed in terms of determination of UIV and Risser sign to identify the risk factors of this phenomenon by using Fisher's exact test. Eleven patients were identified with proximal adding-on, thus the incidence of it was 8.5%. At last follow-up postoperatively, the average Cobb angle of TL or L and proximal thoracic curve was 9° ± 4° and 11° ± 5°, respectively. Moreover, the incidence of adding-on in Rissex sign grade 0 to 1 (3/8) was higher than that of grade 2 to 3 (12.1%) and grade 4 to 5 (4.5%). In addition, the incidence of adding-on in UIV lower than UEV group (20.6%) was obviously higher than that of UIV higher than or equal to UEV group (4.2%). The incidence of adding-on for patients with C(7)PL falls away from UIV (19.5%) were obviously higher than that of patients with C(7)PL falls between the pedicle and lateral margin of UIV (3.6%) and between bilateral pedicles of UIV (3.0%). Each group showed significant difference for the incidence of adding-on by Fisher's exact test (P < 0.05). There exists the risk of proximal thoracic curve decompensation, with a not low rate, after anterior selective fusion for major TL or L curve AIS. The determination of UIV relative to UEV and the skeletal maturity of the patient are the two factors closely associated with the presence of such a phenomenon.

Treatment of Thoracolumbar Burst Fractures by Means of Anterior Fusion and Cage

Retrospective case series. To evaluate the outcome of treating acute thoracolumbar burst fractures using anterior corpectomy and reconstruction with a mesh cage and instrumentation. There is increasing interest in using an anterior mesh cage with instrumentation after corpectomy for burst fractures. However, there is only limited information on this technique in the literature. Twenty-two patients (mean age 37.6 y old) that had sustained a thoracolumbar burst fracture were included in this study. On admission, 20 patients (90.9%) had an incomplete neurological deficit. An anterior thoracolumbar approach was used to perform anterior corpectomy and reconstruction with a mesh cage and lateral fixation with screws and dual rods. We studied the operation date and delayed the blood loss, and we used the American Spinal Injury Association grade to evaluate the neurological status before surgery and in the follow-up period. Local kyphosis measured by the Cobb method was compared before and after the surgery using Wilcoxon signed-rank test/2-tailed test for analysis. Ninety percent of patients were operated within 2 days after admission and all were followed for a minimum of 25 months. The mean follow-up period was 47.4 months (range, 25 to 71 mo). Blood loss averaged 1445 mL. Of the 20 patients with incomplete neurological lesions, there were 6 (30%) patients with an improvement of at least 1 American Spinal Injury Association grade. No neurological deterioration was observed in any case. The local kyphosis measured by the Cobb method was improved from a mean of 15 degrees preoperative to a mean of 9.6 degrees in early postoperative period (P=0.002). The mean after 2 years was 11.5 degrees (P=0.011). There was no instrumentation failure. Anterior thoracolumbar decompression and fusion secured with an anterior mesh cage and instrumentation in thoracolumbar burst fractures provided excellent immediate reduction of post-traumatic local kyphosis.

Anterior Thoracolumbar Corpectomies: Approach Morbidity With and Without an Access Surgeon

Anterior approaches for thoracolumbar corpectomies can have significant morbidity. Spine surgeons have historically performed their own anterior approaches, but recently access surgeons are being used more frequently. To evaluate the morbidity rates of approaches performed by an access surgeon and by an approach-trained spinal neurosurgeon. From 2004 to 2008, 46 patients undergoing anterior thoracolumbar corpectomies (levels T2-L5) by the senior author (D.C.) were identified and subdivided into 2 groups based on whether an access surgeon was involved. Nine patients were excluded, leaving 37 patients in the final analysis. Blood loss, operative times, length of hospital stay, complications, and neurological outcomes were evaluated. Eighteen patients had anterior spinal access by an approach-trained spinal neurosurgeon, and 19 patients underwent the approach by an access surgeon. Surgeries performed by the spinal neurosurgeon alone were comparable to those performed by an access surgeon with respect to operative time, days spent in the hospital, blood loss, complication rates, and improvement in neurological function. There appears to be no increased morbidity of anterior approaches performed by an approach-trained spinal neurosurgeon compared with approaches performed by an access surgeon in terms of operative time, complication rate, and improvement in neurological function.

Anterior thoracolumbar reconstruction surgery for late collapse following vertebroplasty: report of three cases

Although vertebroplasty (VP) using polymethylmethacrylate (PMMA) is thought to be an effective procedure for osteoporotic vertebral compression fractures, several complications have been reported. In this paper, we present three patients who developed local kyphotic deformity as a result of late collapse of the cemented vertebrae. In all patients we safely removed the PMMA block through an anterior approach and anterior reconstruction was performed successfully. In only one patient who had a three column unstable injury with fractured posterior elements was additional posterior spinal fixation needed. In conclusion, VP is thought to be an effective and minimal invasive technique to treat osteoporotic compression fractures in older patients. Once collapse or nonunion of the treated vertebral body occurs, however, removal of the cement and anterior reconstruction may be required to realign of the affected segments and reconstruct the spine.

Transverse plane pelvic rotation increase (TPPRI) following rotationally corrective instrumentation of adolescent idiopathic scoliosis double curves

BackgroundWe have occasionally observed clinically noticeable postoperative transverse plane pelvic rotation increase (TPPRI) in the direction of direct thoracolumbar/lumbar rotational corrective load applied during posterior instrumentation and arthrodesis for double (Lenke 3 and 6) adolescent idiopathic scoliosis (AIS) curves. Our purposes were to document this occurrence; identify its frequency, associated variables, and natural history; and determine its effect upon patient outcome.MethodsTransverse plane pelvic rotation (TPPR) can be quantified using the left/right hemipelvis width ratio as measured on standing posterior-anterior scoliosis radiographs. Descriptive statistics were done to determine means and standard deviations. Non-parametric statistical tests were used due to the small sample size and non-normally distributed data. Significance was set at P < 0.05.ResultsSeventeen of 21 (81%) consecutive patients with double curves (7 with Lenke 3 curves and 10 with Lenke 6) instrumented with lumbar pedicle screw anchors to achieve direct rotation had a complete sequence of measurable radiographs. While 10 of these 17 had no postoperative TPPRI, 7 did all in the direction of the rotationally corrective thoracolumbar instrumentation load. Two preoperative variables were associated with postoperative TPPRI: more tilt of the vertebra below the lower instrumented vertebra (-23° ± 3.1° vs. -29° ± 4.6°, P = 0.014) and concurrent anterior thoracolumbar discectomy and arthrodesis (5 of 10 vs. 7 of 7, P = 0.044). Patients with a larger thoracolumbar/lumbar angle of trunk inclination or larger lower instrumented vertebra plus one to sacrum fractional/hemicurve were more likely to have received additional anterior thoracolumbar discectomy and arthrodesis (c = 0.90 and c = 0.833, respectively).Postoperative TPPRI resolved in 5 of the 7 by intermediate follow-up at 12 months. Patient outcome was not adversely affected by postoperative TPPRI, whether or not it persisted.ConclusionsOur findings suggest that TPPRI is a decompensation caused by extension of the corrective thoracolumbar rotational load into the lumbosacral hemicurve below. As posterior instrumentation of adolescent idiopathic scoliosis becomes increasingly more effective in the transverse plane, postoperative TPPRI may become more widely noticed. This study provides some assurance that recompensation usually occurs, but that in either event TPPRI does not seem to affect clinical outcome.

The biomechanical contribution of varying posterior constructs following anterior thoracolumbar corpectomy and reconstruction

Thoracolumbar corpectomy is a procedure commonly required for the treatment of various pathologies involving the vertebral body. Although the biomechanical stability of anterior reconstruction with plating has been studied, the biomechanical contribution of posterior instrumentation to anterior constructs remains unknown. The purpose of this study was to evaluate biomechanical stability after anterior thoracolumbar corpectomy and reconstruction with varying posterior constructs by measuring bending stiffness for the axes of flexion/extension, lateral bending, and axial rotation. Seven fresh human cadaveric thoracolumbar spine specimens were tested intact and after L-1 corpectomy and strut grafting with 4 different fixation techniques: anterior plating with bilateral, ipsilateral, contralateral, or no posterior pedicle screw fixation. Bending stiffness was measured under pure moments of +/- 5 Nm in flexion/extension, lateral bending, and axial rotation, while maintaining an axial preload of 100 N with a follower load. Results for each configuration were normalized to the intact condition and were compared using ANOVA. Spinal constructs with anterior-posterior spinal reconstruction and bilateral posterior pedicle screws were significantly stiffer in flexion/extension than intact spines or spines with anterior plating alone. Anterior plating without pedicle screw fixation was no different from the intact spine in flexion/extension and lateral bending. All constructs had reduced stiffness in axial rotation compared with intact spines. The addition of bilateral posterior instrumentation provided significantly greater stability at the thoracolumbar junction after total corpectomy than anterior plating and should be considered in cases in which anterior column reconstruction alone may be insufficient. In cases precluding bilateral posterior fixation, unilateral posterior instrumentation may provide some additional stability.

The transpedicular approach compared with the anterior approach: an analysis of 80 thoracolumbar corpectomies

Whereas standard anterior approaches for thoracolumbar corpectomies have commonly been used, the transpedicular technique is increasingly used to perform corpectomies from a posterior approach. The authors conducted a study to analyze whether there was a difference in outcomes by comparing transpedicular corpectomies to standard anterior thoracolumbar corpectomies. The senior author performed thoracolumbar corpectomies in 80 patients between 2004 and 2008. The authors reviewed medical records and follow-up data, consisting of clinic visits, radiographs, or telephone interviews. Neurological outcome, complications, operative times, revision surgery rates, and estimated blood loss (EBL) were evaluated. Thirty-four patients underwent transpedicular corpectomies, and 46 patients underwent anterior thoracolumbar approaches. Single-level transpedicular corpectomies appear to be comparable to anterior-only corpectomies in terms of EBL, operative time, and complication rates. There was a higher complication rate, increased EBL, and longer operative time with anterior-posterior corpectomies compared with transpedicular corpectomies. Patients undergoing transpedicular corpectomies had a greater recovery of neurological function than those in whom anterior-approach corpectomies were performed. The transpedicular corpectomy appears to have a comparable morbidity rate to anterior-only corpectomies, but its morbidity rate is lower than that of anterior-posterior corpectomies.