Posterior Pedicle Screw Instrumentation Research Articles

Retrospective study on the CT evaluation of accuracy of pedicle screw placement in posterior lumbosacral instrumentation

Objectives To evaluate the accuracy of posterior pedicle screw placement in a multicentric retrospective clinical study and analyze the potential reasons of pedicle breaches. Methods From January 2014 to December 2014, 293 patients with conventional posterior pedicle screw instrumentation up to inclusion and exclusion criteria were recruited from 3 different hospitals. The operative levels included L4 in 219 cases, L5 in 270 cases and S1 in 95 cases. The screw positions in the pedicles were verified by 2 professional observers independently under computed tomography reconstruction within 24 hours to 48 hours postoperatively. The locations and grades of breached pedicles were recorded in each segment and related factors were analyzed. Pedicle breach rates in 3 hospitals were stratified and analyzed as well. All patients were followed up and neurological deficits as well as other postoperative complications were registered. Results There were 280 pedicle breaches in a total of 1166 instrumented pedicles of 293 patients. The breach rates in different levels were listed as 29.0% (126/436) in L4, 24.5% (132/539) in L5 and 11.5% (22/191) in S1. There were no significant differences in pedicle breach rates between L4 and L5, while the breach rates in L4 and L5 were both significantly higher than those in S1. For severe violation from L4 to S1, 6.3% (8/126), 14.4% (19/132) and 36.4% (8/22) were confirmed respectively. The incidences of high risk pedicle breach (grade III, grade IV) of L5 and S1 were significantly higher than those of L4. Furthermore, the inferomedial breach rates quantified from L4 to S1 were 58.7% (74/126), 75% (99/132), 86.4% (19/22) respectively. The breach rates in the inferomedial wall of the L5, S1 pedicles were statistically higher than those of L4. Pedicle breach rates among 3 hospitals varied while the characteristics of the locations, the grades and the segments of breached pedicles were similar to overall results in each hospital. There were 9 cases of cerebrospinal fluid leakage and 2 cases of transient nerve root injuries. Conclusion There are no significant differences in pedicle breach rates between L4 and L5. However, pedicle breach rates in L4 and L5 are statistically higher than those in S1. The incidence of high risk pedicle breach and inferomedial wall breach of L5 and S1 are significantly higher than that of L4. In addition, the incidences of pedicle breaches and related complications occurred more in lower-level hospitals. Key words: 【Key word】Lumbar vertebrae; Sacrum; Spinal fusion; Bone Screws

Preoperative LIV Tilt Affects Post Operative Coronal Imbalance in Patients with Lenke 5C Scoliosis

Introduction Lenke 5C curves are increasingly being treated through posterior pedicle screw based correction techniques. We evaluated different preoperative radiological parameters which could affect post operative coronal imbalance (POCI) in patients with Lenke 5C scoliosis treated with posterior instrumented correction. Methods We retrospectively evaluaed twenty-three cases with Lenke 5C scoliosis who underwent selective posterior pedicle screw based deformity correction. Fusion was performed from proximal neutral to distal stable vertebra. Preoperative, immediate post operative and final whole spine standing radiographs were analyzed. The pre-operavtive radiological parameters were assessed including lower instrumented vertebra(LIV) tilt and translation, Cobb angle,C7 offset from CSVL, lumbar lordosis and upper instrumented vertebra(UIV) tilt and translation. Post-operatively we assessed the correction in cobb angle and post-operative coronal imbalance. Results Twenty -three patients had a mean age: 11.8 ± 4.6 years, with 4 males and 19 females. There was a significant improvement in Cobb angle from mean of 55 ± 13.3° to mean of 14.7 ± 8.8°. Nineteen patients had lower instrumented vertebra at L4, 3 at L3 and one at L5. Correction was maintained with no significant loss in the late post op period (15.2 ±8.9 degrees). The mean pre op C7-CSVL distance was 24.7 mm While eight patients had immediate post operative coronal imbalance (POCI), six of them balanced at a mean 8.2 months. Four patients had POCI at the time of final follow-up including two, who developed late imbalance. POCI correlated with pre operative LIV tilt only > 25° ( p < 0.05) and not with LIV translation, UIV tilt or translation. Five of the eight patients with immediate POCI and all four patients with late POCI had preoperative LIV tilt > 25°. Conclusion In Lenke 5C scoliosis treated by posterior pedicle screw instrumentation, patients with a preoperative LIV tilt (>25°) have a risk of developing POCI.

Spinopelvic Alignment and Functional Outcome after Circumferential Fusion for Low-grade Isthmic Spondylolisthesis

Introduction Functional outcomes after surgery for low-grade isthmic spondylolisthesis(LGIS) is reported limitedly for combined posterior and anterior approach procedures. Imbalances in the sagittal alignment of spine and pelvis are increasingly seen as the reason for the development and progression of LGIS. Aims of this study: 1) functional outcome, 2) the effects on spinopelvic alignment, after circumferential fusion. Surgical treatment goals are restoration of stability, reduction of slippage, restoration of disc height and angulation, correction of spinopelvic parameters toward neutral values, and improve functional status. We hypothesized 1) a significant improvement on clinical outcome at 2-year follow-up and 2) a stable post-operative situation around the targeted vertebrae and restoration of the spinopelvic parameters to values seen in healthy subjects. Materials and Methods 43 subjects enrolled with LGIS at L5-S1. Each subject received a posterior decompression and pedicle screw instrumentation followed by an instrumented anterior lumbar interbody fusion in two separate procedures. (1) Outcome measures were registered pre-operative and after 12 and 24 months. Primary outcome was functional status (ODI). Secondary outcomes: Quality of Life (SF-36 subdomains, EQ-5D subscales), and pain intensity (VAS back and leg pain). (2) Full spine radiographs were taken pre-operative and after 3, 12, and 24 months postoperative. Obtained spinopelvic parameters are: sacral slope, pelvic tilt, pelvic incidence, thoracic kyphosis, L5-S1 lordosis, L1-S1 lordosis and sagittal vertical axis. The degree of slippage reduction and L5-S1 angular motion was measured. To evaluate both study aims a repeated measures ANOVA was used to indicate differences over time. Results 42 patients (25 female), average age 39,0 (25–51) with an average BMI 25,8 (21,5–30,4) participated in the study. Functional results are given as means with (standard deviation) pre-operative, at 12 months and 24 months postoperative for ODI: 35,0 (14,4); 10,0 (15,0); 9,5 (15,3); for SF-36 PCS: 42,0 (12,7); 70,5 (21,0); 71,5 (21,5); for SF-36 MCS: 64,0 (16,6); 81 (19,4); 81,5 (19,5); for EQ-5D: 0,56 (0,29); 0,84 (0,28); 0,83 (0,240); for VAS (back pain): 64,5 (26,2); 16,0 (32,2); 22,0 (23,9). Degree of slip decreased significantly from 27,0% (11,9%) to 7,4% (11,7%) postoperatively. Angular motion decreased statistically significant immediately postoperative and remained stable thereafter. L5-S1 and L1-S1 lordosis and sacral slope showed a significant increase postoperatively, whereas the pelvic tilt and sagittal vertical axis significantly decreased. Conclusion Circumferential instrumented fusion for LGIS via combined approach improves functional outcome at short term follow-up. After careful patient selection and unsuccessful conservative management surgical treatment is a suitable alternative with predictable short term outcome. Circumferential fusion corrects deformity and creates a stable situation in LGIS. We find that sagittal alignment is probably influenced positively, by bringing the SVA in a more neutral position.

Causes for failed posterior pedicle screw instrumentation for thoracolumbar fractures

Objective To analyze the causes for the failures after posterior pedicle screw instrumentation for thoracolumbar fractures. Methods From June 2003 to December 2014, 182 patients with thoracolumbar fracture were treated by fixation through the posterior approach using pedicle screws and fully followed up in our institute . We analyzed the cases of postoperative infection, recovery of neural symptoms, breakage and loosening of pedicle screws and connecting rod, non-union of the fractured vertebra, and correction loss of kyphosis in associations with the AO classification and Loading Sharing Classification of Spine Fracture (LSCSF) system, osteoporosis, intervertebral disc injury and methods of internal fixation. Results In this series, altogether 27 cases failed (14.8%) . The rate of postoperative infection was 1.1% (2/182) . The rate of breakage of pedicle screw or connecting rod was 7.7% (14/182) . The implant breakage rates for fractures of AO types A1, A2 and A3.1 were significantly lower than for other types (P<0.05) . The implant breakage rate for the patients with ≤6 LSCSF points was significantly lower than for those with ≥7 LSCSF points (P<0.05) . The implant breakage occurred in 3 cases of those who underwent fixation of one normal vertebra respectively below and above the two contiguous segments but not in those who underwent additional fixation of the injured vertebrae. The rate of screw loosening was 2.2% (4/182) . The non-union rate of the injured vertebra was 2.7% (5/182) . The rate of kyphosis recurrence was 1.1% (2/182). Conclusions To prevent the failure of posterior pedicle screw fixation, surgeons should pay more attention to the following key points before operation: the type and evaluation of spinal fractures, a proper approach and method of internal fixation, and the weight bearing capability of the anterior column. Key words: Spinal fractures; Bone nails; Treatment failure

Intraoperative computed tomography navigation for transpedicular screw placement in posterior instrumentation and correction of adolescent idiopathic scoliosis

Background: Intraoperative computed tomography (iCT) navigation produces high resolution real-time 3-dimensional images, which can be obtained after the well-prepared surgical field of posterior spinal elements is scanned by the iCT. There is a paucity of studies reporting the feasibility of the iCT navigation system integrated into posterior instrumentation and correction for adolescent idiopathic scoliosis (AIS). Purpose: This study is to evaluate the safety and accuracy of transpedicular screws (TPS) placement in AIS using the iCT navigation. Methods: We performed a retrospective review of records of the Spine Operation Registry at the authors’ institution to identify AIS patients who underwent correction with posterior pedicle screw instrumentation via the iCT navigation from year 2010 to 2014. Results: A total of 17 AIS patients underwent correction with posterior instrumentation via iCT navigation. A total of 245 screws including 175 thoracic screws and 70 lumbar screws were placed. The mean estimated blood loss was 718 ml (range, 350–1,500 ml) and the average operative time was 266 min (range, 150–420 min). The mean dose of patient radiation exposure was 20.1 mSv (range, 13.1–30 mSv) and the mean radiation dose per single level exposure was 1.9 mSv (range, 1.2–2.7 mSv). The average Cobb angles of major curve before surgery, in the immediate postoperative period, and at the most recent follow-up were 53.2 degrees, 16.5 degrees, and 17.7 degrees, respectively. The average correction rate was 67% (range, 50%–82%) with an average of 10.7 fused levels (range, 8–14 fused levels). A total of 236 screws (96%) were positioned in the pedicle without cortical breach, including 167 thoracic screws (95%) and 69 lumbar screws (99%). There were 90 wellpositioned screws (96%) on the concave side and 77 well-positioned screws (95%) on the convex side of the thoracic curves. There were 32 wellpositioned screws (100%) the concave side and 37 well-positioned screws (97%) on the convex side of the lumbar curves. Breach grade 1 occurred in one thoracic pedicle screw and one lumbar pedicle screw, and breach grade 2 occurred in seven thoracic pedicle screws. All screws with breach grade 2 were removed. The TPS removal rate was 3% (7/245) without any neurovascular sequela. Conclusion: TPS placement using the iCT navigation system resulted in 96% accuracy in posterior instrumentation and correction of AIS. A malpositioned pedicle screw could be immediately removed during real-time assessment of the TPS position, and no secondary operation was required.

"One-Shot" CT image navigated circumferential fusion in a single lateral decubitus position: surgical technique.

The purpose of this paper was to summarize the surgical peculiarities of a combined approach for minimally invasive lateral retroperitoneal interbody fusion and posterior percutaneous pedicle screw instrumentation in the same lateral decubitus position using intraoperative computed tomography-based navigation.

The impact of posterior temporary internal distraction on stepwise corrective surgery for extremely severe and rigid scoliosis greater than 130°.

To investigate the efficacy and safety of temporary internal distraction corrective surgery for extremely severe scoliosis. Eleven scoliosis patients (3 males and 8 females) with curves ≥130° (mean 148.8°; range 130°-157°) who underwent a two-stage surgery, including a posterior temporary internal distraction correction and definitive posterior spinal correction with posterior pedicle screw instrumentation from 2008 to 2011 were retrospectively reviewed. Minimum follow-up was 2-years (mean 41.8months; range 27.0-63.0months). The analysis focused on the impact of temporary internal distraction on curve correction, pulmonary function tests (PFTs), complications and surgical outcomes. Neurosurveillance of sensory (somatosensory-evoked potentials) and motor (motor-evoked potentials) potential was performed in all cases. Posterior instrumentation was used in all patients. After the use of internal distraction, the preoperative major curve (mean 148.8°; range 130°-157°) was corrected to a mean of 79° (range 63°-87°), the T5-T12 kyphosis Cobb angle (mean 79°; range 30°-97°) was corrected to a mean of 59° (range 20°-75°), the coronal imbalance (mean 0.8cm; range -3.6 to 2.8cm) was improved to a mean of 0.6cm (range -1.5 to 2.0cm), the forced vital capacity percentage (FVC%) was improved from 59.3±11.6 to 68.7±13.7, and the forced expiratory volume in 1s (FEV1%) was improved from 61.4±13.6 to 71.3±9.3. The average increase in body height was 6.7cm, and the dorsum razor was corrected to 3-5cm. During definitive surgery, the final major curves were corrected to a mean of 55° (range 32°-72°), the T5-T12 kyphosis Cobb was corrected to 35° (range 15°-68°), the coronal imbalance was improved to 0.5cm (range -1.2 to 1.8cm), the FVC% was improved to 71.2±8.3, the FEV1% was improved to 76.3±16.7, the increase in body height was 3.1cm, and the dorsum razor was corrected to 1-3cm. The mean interval time between the two surgeries was 3.5months. None of the patients exhibited postoperative neurologic deficits or infections. No instrument complications were found during the final follow-up. Temporary internal distraction in a two-stage corrective surgery provided patients who had extremely severe and rigid scoliosis, an effective and safe solution for scoliosis without significant complications.

5-year minimum follow-up study of Surgical &amp; Radiological outcomes of Thoracoscopic assisted Anterior Instrumented fusion compared to posterior hook and pedicle screw instrumentation in the treatment of Adolescent Idiopathic Scoliosis

Group 2 &3 Posterior Instrumentation (PI): 91 patients, average age 14.2 yrs. The posterior group was divided into all Hook/ hybrid (Group 2, n=45) and all Pedicle screw construct (Group 3, n=46), for evaluation of radiological outcomes. The groups were compared for various surgical and radiological outcomes at immediate post-op, 2 and 5 year intervals. Average follow-up 6.6 years (5-12 yrs). Results The groups were similar with regards to age, Risser grade, and Cobb angle of Main Thoracic curve.

Long-term results still favor nonoperative treatment of stable thoracolumbar burst fractures: commentary on an article by Kirkham B. Wood, MD, et al.: "Operative compared with nonoperative treatment of a thoracolumbar burst fracture without neurological deficit. A prospective randomized study with follow-up at sixteen to twenty-two years".

Burst fractures of the thoracolumbar spine are common, but no consensus has been reached as to the best treatment. Although all burst fractures are characterized by the common finding of retropulsion of the posterior vertebral body wall into the spinal canal, burst fractures vary in severity with respect to amount of comminution, canal narrowing, associated neurologic deficit, and involvement of posterior structures. The latter structures are of primary importance in defining stability. To determine the best treatment, the authors conducted a randomized clinical trial from 1992 to 1998 in which they compared the outcomes of forty-seven patients who received either surgical or nonoperative treatment of a stable thoracolumbar burst fracture. This type of fracture has an intact posterior osteoligamentous complex. Nonoperative care consisted of bracing or casting. The surgical group was treated by anterior corpectomy and fusion with a plate or short-segment (two to four-level) posterior pedicle-screw instrumentation and arthrodesis. The …

Single-stage anterior debridement and fibular allograft implantation followed by posterior instrumentation for complicated infectious spondylitis: report of 20 cases and review of the literature.

Complicated infectious spondylitis is an infrequent infection with severe spinal destruction, and is indicated for combined anterior and posterior surgeries. Staged debridement and subsequent reconstruction is advocated in the literature. The purpose of this study is to evaluate the feasibility and clinical outcome of patients who underwent single-stage combined anterior debridement and fibular allograft implantation followed by supplemental posterior fixation for complicated infectious spondylitis.We retrospectively reviewed the medical records of 20 patients who underwent single-stage combined anterior and posterior surgeries for complicated infectious spondylitis from January 2005 to December 2010. Complicated infectious spondylitis was defined as at least 1 vertebral osteomyelitis with pathological fracture or severe bony destruction and adjacent discitis, based on imaging studies. The severity of the neurological status was evaluated using the Frankel scale. The clinical outcomes were assessed by careful physical examination and regular serological tests to determine the visual analog scale (VAS) score and Macnab criteria. Correction of the sagittal Cobb angle on radiography was also compared before and after surgery. The Wilcoxon signed-rank test was used to analyze patient surgical prognosis and radiological findings.All patients with complicated infectious spondylitis were successfully treated by single-stage combined anterior and posterior surgeries. No patients experienced neurologic deterioration. The average VAS score was 7.8 before surgery and significantly decreased to 2.1 at discharge. Three patients had excellent outcomes and 17 had good outcomes, based on Macnab criteria. The average length of the allograft for reconstruction was 64.0 mm. Kyphotic deformity improved in all patients, with an average correction angle of 13.4°. There was no implant breakage or allograft dislodgement during at least 36 months of follow-up.Single-stage anterior debridement and fibular allograft implantation followed by posterior pedicle screw instrumentation provide immediate stability, satisfactory alignment, and successful infection control. Fibular allograft implantation seems to be a good alternative for anterior reconstruction; it can proceed to bony incorporation and avoids donor site morbidity.

Direct lateral retroperitoneal approach for the surgical treatment of lumbar discitis and osteomyelitis.

The medical management of discitis and osteomyelitis with long-term antibiotic therapy and bracing usually results in eradicated infection. Surgical management is appropriate when medical management fails and in some cases with pyogenic deformity or neurological deficit. The success of surgery depends on adequate debridement of the necrotic infected disc and vertebral body, along with anterior column reconstruction and vertebral stabilization. Debridement is typically performed via an anterior retroperitoneal approach, which can necessitate mobilization of the great vessels for proper exposure. Mobilization can be technically difficult and lead to vascular injury. The purpose of this study was to evaluate an alternative technique for the surgical treatment of lumbar discitis and osteomyelitis using a direct lateral retroperitoneal approach, which allows for thorough debridement and anterior column reconstruction while avoiding the need to mobilize the great vessels. A retrospective chart analysis was performed for all patients who had presented with lumbar discitis and osteomyelitis and had undergone surgical management via the direct lateral retroperitoneal approach in the period from 2006 to 2013. Collected data included surgical blood loss, perioperative complications (wound infection, vascular injury, approach-related complications, and neurological injury), need for secondary procedures, microbiological and laboratory results, and efficacy of infection eradication. Imaging studies were reviewed as well. Ten patients, 7 male and 3 female, underwent this procedure at the authors' institution in the defined period. Average blood loss was 272 ml (range 150-800 ml, with 800 ml in the only 2-level case). There were no vascular injuries. Average follow-up was 680 days, although 4 patients did not complete the follow-up beyond 6 months. Eight patients underwent immediate posterior pedicle screw instrumentation. Two patients did not undergo posterior instrumentation, and one of these developed a kyphotic deformity that required a secondary posterior procedure. Infection was eradicated in all patients according to a history, physical examination, imaging studies, and laboratory parameters (complete blood count, erythrocyte sedimentation rate, and C-reactive protein). One patient developed a painful neuroma at the iliac crest harvest site, and one patient had a retroperitoneal hematoma. Otherwise, there were no approach-related neurological injuries or complications. Neither was there any postoperative surgical site infection. The direct lateral approach for the surgical treatment of lumbar discitis and osteomyelitis allows for thorough debridement and spinal reconstruction without the need to mobilize the great vessels. This technique effectively eradicated infection in all cases, with reasonable blood loss and no vascular injuries. This approach should be considered as an alternative to the open anterior approach. The authors recommend posterior instrumentation to prevent the development of kyphosis.

An Innovative Fulcrum-Bending Radiographical Technique to Assess Curve Flexibility in Patients With Adolescent Idiopathic Scoliosis

A prospective clinical and radiographical study. To introduce a redesigned fulcrum-bending radiographical (FBR) method, and to validate the effectiveness of this method in assessing patients with (AIS). Several radiographical methods exist to evaluate curve flexibility in patients with AIS. The technique of FBR has been demonstrated to better predict coronal plane correction of main thoracic curves. However, the amount of weight applied may affect the results of flexibility evaluation and have not been well studied to date. Seventeen patients with AIS with 19 curves were involved in this study. The assessment of radiographs included preoperative standing posterior-anterior, supine side-bending, traditional FBR, new FBR (CH-FBR), and postoperative standing posterior-anterior radiographs. CH-FBR was performed at variable device heights while measuring the applied weight at the apex. Preoperatively, the mean Cobb angle was 47.5° ± 8.8° on the posterior-anterior radiographs, 14.3° ± 7.0° on supine side-bending radiographs, 13.3° ± 5.7° on traditional FBR, 11.3° ± 4.5° at the lowest height using CH-FBR (lowest weight), and 7.8° ± 4.1° at the optimized height using CH-FBR (maximal weight). Postoperatively, the mean Cobb angle was 9.1° ± 5.2°. There was a significant difference found between supine side-bending radiograph and postoperative Cobb angle (P = 0.001), traditional FBR, and postoperative Cobb angle (P = 0.002). There was no significant difference found between optimized height CH-FBR and postoperative Cobb angle (P = 0.16). Correlation analysis indicated that the maximum height of CH-FBR positively correlated with maximum weight applied (r = 0.68, r= 0.46, P = 0.001). CH-FBR is a more reliable and effective method than traditional FBR and supine side-bending radiographs to measure curve flexibility in patients with AIS. Moreover, the flexibility suggested by the CH-FBRs more closely approximated the postoperative results from posterior pedicle screw instrumentation. 3.

Traumatic retropulsion of T10 vertebra in a 5-year-old boy with involvement of neurocentral synchondrosis: a case report and review of the literature

This is a case report of a traumatic retropulsion of the T10 vertebral body in a 5-year-old boy. This paper aims to describe a rare pediatric fracture where there was involvement of the neurocentral synchondrosis (NCS) and to evaluate the characteristics of this type of fractures in children. The NCS is the junction between the vertebral body and the pedicle bilaterally where the vertebra grows horizontally. It closes between 11 and 16 years. It is a known location for spine fracture. However, it was mainly reported in children less than 2 years of age secondary to nontraumatic injury and at the junction levels of the spine. This is the first case of a fracture involving the NCS in a child older than 2 years, due to trauma, and in a non-junctional area of the spine. This 5-year-old boy was involved in a motor vehicle collision where he was ejected from the car. He had bilateral lower limb paresthesia and weakness. The fracture involved the neurocentral synchondrosis on the left side and impacted the vertebral body into the pedicle on the right side. Additionally, there was posterior vertebral element injury. He was treated with wide laminectomy and posterior pedicle screw instrumentation. At 18 months of follow-up, the patient showed a normal neurologic status and a normal alignment of the spine. Traumatic retropulsion of the thoracic spine with involvement of the NCS is possible in young age when exposed to a significant trauma. Restoration of spine alignment and normal neurological function could be achieved with a single posterior approach. - Pediatric fractures are uncommon and tend to affect junction areas. - A fracture through the neurocentral synchondrosis is possible before the age of closure (11-16 years) with forcible trauma. - Single posterior decompression and instrumented fusion is sufficient to restore alignment and neurological function.

Multilevel extreme lateral interbody fusion (XLIF) and osteotomies for 3-dimensional severe deformity: 25 consecutive cases

BackgroundThis is a retrospective review of 25 patients with severe lumbar nerve root compression undergoing multilevel anterior retroperitoneal lumbar interbody fusion and posterior instrumentation for deformity. The objective is to analyze the outcomes and clinical results from anterior interbody fusions performed through a lateral approach and compare these with traditional surgical procedures. MethodsA consecutive series of 25 patients (78 extreme lateral interbody fusion [XLIF] levels) was identified to illustrate the primary advantages of XLIF in correcting the most extreme of the 3-dimensional deformities that fulfilled the following criteria: (1) a minimum of 40° of scoliosis; (2) 2 or more levels of translation, anterior spondylolisthesis, and lateral subluxation (subluxation in 2 planes), causing symptomatic neurogenic claudication and severe spinal stenosis; and (3) lumbar hypokyphosis or flat-back syndrome. In addition, the majority had trunks that were out of balance (central sacral vertical line ≥2 cm from vertical plumb line) or had sagittal imbalance, defined by a distance between the sagittal vertical line and S1 of greater than 3 cm. There were 25 patients who had severe enough deformities fulfilling these criteria that required supplementation of the lateral XLIF with posterior osteotomies and pedicle screw instrumentation. ResultsIn our database, with a mean follow-up of 24 months, 85% of patients showed evidence of solid arthrodesis and no subsidence on computed tomography and flexion/extension radiographs. The complication rate remained low, with a perioperative rate of 2.4% and postoperative rate of 12.2%. The lateral listhesis and anterior spondylolisthetic subluxation were anatomically reduced with minimally invasive XLIF. The main finding in these 25 cases was our isolation of the major indication for supplemental posterior surgery: truncal decompensation in patients who are out of balance by 2 cm or more, in whom posterior spinal osteotomies and segmental pedicle screw instrumentation were required at follow up. No patients were out of sagittal balance (sagittal vertical line <3 cm from S1) postoperatively. Segmental instrumentation with osteotomies was also more effective for restoration of physiologic lumbar lordosis compared with anterior stand-alone procedures. ConclusionsThis retrospective study supports the finding that clinical outcomes (coronal/sagittal alignment) improve postoperatively after minimally invasive surgery with multilevel XLIF procedures and are improved compared with larger extensile thoracoabdominal anterior scoliosis procedures.

Transforaminal Lumbar Interbody Fusion With rhBMP-2 in Spinal Deformity, Spondylolisthesis, and Degenerative Disease–Part 1

Retrospective review of prospectively collected data. To evaluate long-term clinical outcomes and complications of the transforaminal lumbar interbody fusion (TLIF) procedure from a large consecutive series, without industry funding. Clinical outcomes and complications are analyzed by diagnosis and primary versus revision surgery to assess whether TLIF with bone morphogenic protein (BMP) is appropriate for common use in deformity, spondylolisthesis, and degenerative disease. A common method for achieving spinal arthrodesis includes TLIF with a cage and off-label interbody BMP-2, supported by posterior arthrodesis and a pedicle screw construct. There are no large studies analyzing outcomes and complications after TLIF in different diagnoses, for primary and revision surgery, leading some to question the widespread use of TLIF. A total of 509 consecutive adults underwent open posterior instrumented fusion, augmented with TLIF at 872 discs using a cage and rhBMP-2, with minimum 2-year follow-up. Cohort diagnoses included 179 degenerative, 207 spondylolisthesis, and 123 deformity patients. Patient age averaged 61 years, 207 had undergone prior decompression or fusion surgery. All patients underwent posterior instrumented fusion and pedicle screw instrumentation at average 3.6 levels (range, 1-16); all patients had TLIF 1.7 levels (range, 1-4 levels) with BMP and autograft, stabilized with an interbody cage. At average 59 months follow-up, 12 patients developed pseudoarthrosis, 8 at TLIF levels (8/872 discs, 0.92%) most commonly at L5-S1 (6/8). Significant clinical improvement was noted in patients with deformity, spondylolisthesis, and degenerative disease undergoing primary and revision surgery. Overall, visual analogue scale preoperative score was 6.6, at 1 year 3.8, at 2 years 3.5 (P < 0.001) and the preoperative ODI was 50.9, at 1 year 36.1, and at 2 years 35.0 (P < 0 0.001). Pain medication requirements also declined. The efficacy of TLIF with BMP is supported in this large series with long-term follow-up, independent of industry. Reliable fusion and improved outcomes can be expected in adults undergoing TLIF for deformity, spondylolisthesis, and degenerative disease. Most complications occurred in patients with deformity. 3.

Quantitative Assessment of Retrograde Ejaculation Using Semen Analysis, Comparison With a Standardized Qualitative Questionnaire, and Investigating the Impact of rhBMP-2

This was a prospective study evaluating the incidence of retrograde ejaculation (RE) after anterior lumbar interbody fusion (ALIF) based on laboratory analysis of semen and urine. The purpose of this study was to investigate the incidence of RE based on quantitative semen analysis and to compare the rate with that identified using a standardized qualitative questionnaire administered by telephone. RE is a specific sexual dysfunction in which semen passes into the bladder during ejaculation. It has long been a known possible complication of ALIF associated with injury to the superior hypogastric plexus occurring during access to the anterior lumbar spine. Although reported in multiple studies, there is no standardized assessment for RE and many studies do not describe the methods by which it was assessed. Recently, there has been increased interest in ALIF-related RE with respect to the use of recombinant human bone morphogenetic protein (rhBMP-2). However, how RE was diagnosed remains loosely defined. One possible assessment of RE is to analyze semen and urine after ejaculation. Forty-one male patients undergoing ALIF with posterior pedicle screw instrumentation and fusion at L4-L5 and/or L5-L1 consented to participate in the study. The subjects went to a cryobank for preoperative semen and postejaculatory urine analysis. They returned to the cryobank 3 to 6 months after surgery for repeat testing. The semen analysis consisted of ejaculate volume, total sperm count, concentration, and motility, whereas the urine test reported postejaculatory voided urine for spermatozoa. Postoperatively, patients were called by the principle investigator who conducted an interview based on a standardized questionnaire (completed for 36 patients). Patients were considered to have RE based on the questionnaire if they reported less or no ejaculate fluid. These results were compared with those from the laboratory testing to evaluate the value of the questionnaire in assessing RE. rhBMP-2 was used in 21 of the cases. The incidence of RE was compared in these patients versus those in whom rhBMP-2 was not used. Four patients (9.8%) were diagnosed with RE based on the laboratory analysis, 2 of which resolved spontaneously. Based on the questionnaire, 15 (41.7%) patients reported having RE, including the 4 that were confirmed by laboratory testing. Of the 21 patients treated with rhBMP-2, 2 (9.5%) were diagnosed with RE, 1 of which resolved. Of the 20 patients treated without rhBMP-2, 2 (10.0%) had RE, 1 of which resolved. This study suggests that use of a questionnaire tends to overestimate the incidence of RE as compared with the quantitative semen and urine analysis. Contrary to recent studies using retrospective qualitative review, in this small group with quantitative analysis, use of rhBMP-2 was not related to an increased incidence of RE, with a rate of approximately 10% in both patients receiving, and those not receiving, rhBMP-2. Further study of a larger group using preoperative semen and urine analysis, postoperative standard questionnaire and postoperative semen analysis should be pursued to further investigate the occurrence of RE and to possibly assist in developing and validating a questionnaire for RE assessment.

Anterior Dual Rod Versus Posterior Pedicle Fixation Surgery for the Surgical Treatment in Lenke 5C Adolescent Idiopathic Scoliosis: A Multicenter, Matched Case Analysis of 42 Patients

Study DesignMulticenter matched case analysis. ObjectiveCompare patients with Lenke 5C scoliosis surgically treated with anterior spinal fusion with dual rod instrumentation and anterior column support versus posterior release and pedicle screw instrumentation. Summary of Background DataTreatment of single, structural, lumbar and thoracolumbar curves in patients with adolescent idiopathic scoliosis (AIS) has been the subject of some debate. Previous papers directly comparing these approaches are problematic because of heterogeneity of the groups, nonrandomized protocols, and surgeon bias and variation of instrumentation (upper instrumented vertebrae and lower instrumented vertebrae) in relation to the defined Cobb angle (upper end vertebra and lower end vertebrae). This report sought to remedy these flaws by analyzing a database of Lenke 5C AIS and performing matched cases. MethodsWe analyzed 96 patients with Lenke 5C AIS curves based on radiographic and clinical data at 3 institutions, surgically treated between 2001 and 2005 with minimum 2-year follow-up. Case matched criteria (age within 1 year, sex, curve within 5°, lower end vertebrae, and lower instrumented vertebrae) yielded 21 matched patient pairs. We evaluated and compared multiple clinical and radiographic parameters. ResultsWe observed no significant statistical differences between groups in any preoperative clinical or radiographic parameters. At final follow-up, the major curve measured 8° (83%) in the posterior spinal fusion group, compared with 13° (72%) in the anterior spinal fusion group (p = .002). Estimated blood loss was similar in both groups. Hospital stay was significantly shorter in the posterior spinal fusion group. There were no differences in radiographic complications, such as proximal junctional kyphosis. ConclusionsAt a minimum of 2 years' follow-up in a multicenter, matched case analysis, adolescents with Lenke 5C curves demonstrated statistically significantly better curve correction and shorter hospital stays when treated with a posterior release with pedicle screw instrumented fusion compared with an anterior instrumented fusion with dual rods for similar patient populations.

Quality of life after surgery for neuromuscular scoliosis

Surgery in patients with neuromuscular scoliosis is associated with a higher rate of complications. It is still controversially discussed whether the patients truly benefit from deformity correction. The purpose of this study is to investigate if the quality of life has been improved and if the patients and their caregivers are satisfied with the results of surgery. This is a retrospective clinical outcome study of 46 patients with neuromuscular scoliosis which were treated with primary stable posterior pedicle screw instrumentation and correction. To achieve fusion only autologous bone was used. Follow up was minimum 2 years and maximum 5 years with an average of 36 months. The patients and/or their caregivers received a questionnaire based on the PEDI (pediatric disability inventory) and the GMFS (gross motor function score). The patients (and their caregivers) were also asked if the quality of life has improved after surgery. Only 32 of 46 patients answered the questionnaire. The answers showed a high approval-rate regarding the patients satisfaction with the surgery and the improvement of quality of life. The questionnaire could be answered from 1 (I do not agree) to 4 (I completely agree). The average agreement to the following statements was: i) the quality of life has improved: 3.35; ii) I am satisfied with surgery: 3.95; iii) the operation has fulfilled my expectations: 3.76. The average age at surgery was 12.7 years. The mean pre-operative cobb-angle of the main curve was 83.1° with a correction post-operatively to a mean of 36.9° and 42.6° at final follow-up. That is an average correction of 56.9%. Although spinal fusion in neuromuscular scoliosis is associated with a higher rate of complications our results show that the patients and their caregivers are satisfied with the operation and the quality of life has improved after surgery.

Morbidity and mortality in adult spinal deformity surgery: Norwich Spinal Unit experience

This study analyses the complications of spinal deformity surgery in adults to highlight pre-disposing factors. The clinical records and imaging were reviewed for 48 consecutive patients, 12 males and 36 females, with a mean age of 64 (31-86), who had surgery for spinal deformity. Mean follow-up time was 36 months (24-60). Patient data recorded were age, diagnosis and co-morbidities; deformity assessment: curve type, sagittal and coronal balance, Cobb angle. Operation details: number of instrumented levels, duration and intra-operative complications. complications, re-operations, balance and Cobb angle. 28 patients (58 %) had at least 1, 15 patients (27 %) had 2 and 5 patients (9.5 %) had more than 2 co-morbidities. Average time between 1st presentation and operation was 13 months (1-41). The mean number of levels fused was 10.8 (4-23). In addition to posterior pedicle screw instrumentation, 40 patients had chevron osteotomies and 8 had pedicle substraction osteotomies. Posterior interbody fusions were performed at one level in 17 of which 7 had 2 level fusion. Two patients had combined anterior and posterior approaches. Fusion to the pelvis was performed in 19 patients. There were a total of 27 major and minor complications in 19/48 (39.5 %) patients. Late complications included 5 patients who had revisions for proximal junctional kyphosis, 1 patient had revision for pseudoarthrosis and 4 patients had removal of mal-positioned screws. Factors associated with high complication rate in adult spinal deformity surgery are age, co-morbidities and severe sagittal imbalance at the time of presentation.

Posterior all-pedicle screw instrumentation combined with multiple chevron and concave rib osteotomies in the treatment of adolescent congenital kyphoscoliosis

Background contextCongenital kyphoscoliosis is a disorder that often requires surgical treatment. Although many methods of surgical treatment exist, posterior-only vertebral column resection with instrumentation and fusion seem to have become the gold standard for very severe and very rigid curves. Multiple chevron and concave rib osteotomies have been previously reported to be effective in the treatment of neglected severe idiopathic curves. We hypothesized that this method may also be used successfully in the treatment of congenital kyphoscoliosis. PurposeTo evaluate the effectiveness and safety of multiple chevron osteotomies combined with concave rib osteotomy and posterior pedicle screw instrumentation. Study designRetrospective chart review in the spine service of a large university hospital. Patient sampleAdolescent patients undergoing a specific surgical treatment for the indication of rigid congenital kyphoscoliotic deformity. Outcome measuresRadiographic images were used for the measurement of deformity correction. The Turkish version of the Scoliosis Research Society 22 (SRS-22) Patient Questionnaire has been used as a clinical outcome measure in the patient population. MethodsA retrospective chart review was performed. Patients admitted to Hacettepe Hospital Spine Center during the period of 2005 to 2009 were included. Criteria for inclusion were as follows: adolescent age group (10–16 years); congenital kyphoscoliosis; formation and/or segmentation defect of at least two vertebral motion segments; surgical treatment of deformity by posterior all-pedicle screw instrumentation, multiple chevron osteotomies, and multiple concave rib osteotomies; follow-up of at least 24 months; and a complete set of preoperative, postoperative, and follow-up standing posteroanterior and lateral full spinal radiographs. The patients' hospital records and X-rays were reviewed. Duration of surgery, intraoperative blood loss, postoperative transfusion requirements, postoperative stay in postanesthesia care unit (PACU), time of hospitalization, and complications were recorded. Deformity in both coronal and sagittal planes was analyzed for correction and maintenance of the correction in preoperative, postoperative, and follow-up radiographs. Patients' health-related quality of life was assessed using the SRS-22 questionnaire at the final follow-up. ResultsEighteen patients met the inclusion criteria. Their average age was 13.6 years (range, 11–16 years). Chevron osteotomies were performed at apical segments (three to seven levels) and concave rib osteotomies at Cobb-to-Cobb (five to eight levels). No patient had preoperative cord compression because of the sharply angulated deformity or neurologic deficit. The average preoperative scoliosis was 66.0° (range, 31°–116°), 52.4° (range, 22°–85°) on flexibility X-rays, and became 24.9° (range, 12°–52°) postoperatively. The average preoperative global kyphosis (T2–T12) of 75.9° (range, 50°–106°) became 49.5° (range, 18°–66°). The average preoperative local kyphosis of 71.9° (range, 35°–114°) became 31.4° (range, −44° to 64°). The average intraoperative bleeding was 989 cc, surgical time was 292 minutes, and intraoperative transfusion was 2.3 units. The maximum PACU stay was overnight. There were no neurologic complications except one pneumothorax and one pneumonia. The average follow-up was 34.3 months. At follow-up, average scoliosis was 27.5° (range, 10°–50°), global kyphosis was 50.3° (range, 28°–73°), and local kyphosis was 36.9°(range, −36° to 58°). Performed on the last follow-up, the average scores for the five domains of SRS-22 were 4.3, 4.4, 4.2, 4.1, and 4.8 for function, pain, self-image, mental health, satisfaction, and total, respectively. ConclusionsMultiple chevron and concave rib osteotomies with posterior instrumentation provide an acceptable rate of deformity correction and maintenance of correction at 2 years with acceptable intraoperative bleeding, surgical time, postoperative morbidity, and rate of complications. It can be considered as an alternative in the treatment of rigid congenital curves involving more than three levels or multiple curves separated by at least two segments that would otherwise require multiple vertebral resections.