Additional Posterior Fixation Research Articles

Outcomes of Treatment of Spinal Fractures with the SpineJack System

Background. The use of SpineJack implants in patients with stable spinal fractures and without neurological deficits enables restoration of the shape of the fractured vertebra and significantly accelerates restoration of normal function. In unstable spinal fractures, additional posterior fixation is recommended. This is not recommended in patients with traumatic spinal stenosis. The aim of the study was to evaluate the surgical and functional outcomes of treatment of patients with the SpineJack implant.Material and methods. The objectives of this paper were accomplished on the basis of an evaluation of the outcomes of treatment of 39 patients operated on at the Orthopaedic Oncology Department in Brzozw and the Department of Orthopaedics and Traumatology in the District Hospital in Stalowa Wola in the years 2020-2021. 71% of patients were men; the mean age of women was 54 years and the mean age of men was 41 years. A total of 30 patients suffered traumatic fractures, while 9 patients suffered non-traumatic (pathological) fractures. Fractures were most often located in the lower parts of the thoracic and upper lumbar spine. Patient radiographs taken on the day before, the first day after and 3 months following the surgery were evaluated to assess the correction of vertebral wedging and cement leakage. Functional status was assessed using ODI, the quality of life was assessed with the EQ-VAS and the severity of pain was measured with a VAS.Results. Pain intensity, measured with a VAS scale after the surgery, significantly decreased from the mean preoperative 6.9 to 2.4 three months post-op. The mean functional status of patients (ODI) before surgery was 74.4, compared to 14.8 at 3 months post-op. Mean Quality of life (EQ-VAS) was 56.4 before the surgery and 72.4 at 3 months post-op. The vertebral wedge angle decreased after surgical treatment, from a mean value of 15.8 degrees before surgery to 8.8 degrees after surgical treatment. At three months following the surgery, the mean loss of correction was 2.2 degrees and occurred in 4 patients. The most frequent complication was cement leakage into the disc and into the spinal canal, occurring in 4 and 2 patients, respectively. Conclusions. 1. The use of SpineJack implants in the treatment of stable vertebral fractures enables the restoration of the shape and reduction of the vertebral wedge angle. 2. The quality of life of patients after vertebral fracture treatment with SpineJack implants assessed using the EQ-VAS improved significantly. The severity of pain assessed on a VAS scale decreased significantly and the patients functional status improved according to the ODI. 3.Complications observed during treatment with SpineJack implants include fractures of the vertebral endplate and cement leakage, mostly asymptomatic.

Oblique lateral interbody fusion stand-alone vs. combined with percutaneous pedicle screw fixation in the treatment of discogenic low back pain.

ObjectiveOblique lateral interbody fusion (OLIF) has unique advantages in the treatment of discogenic low back pain (DBP). However, there are few studies in this area, and no established standard for additional posterior internal fixation. The purpose of this study was to investigate the efficacy of OLIF stand-alone vs. combined with percutaneous pedicle screw fixation (PPSF) in the treatment of DBP.MethodsThis retrospective case-control study included forty patients. All patients were diagnosed with DBP by discography and discoblock. Perioperative parameters (surgery duration, blood loss, and muscle damage), complications, Visual analog scale (VAS), and Oswestry Disability Index (ODI) were assessed. Imaging data including cage subsidence, cage retropulsion, fusion rate, and adjacent spondylosis degeneration (ASD) were analyzed.ResultsThere were 23 patients in the OLIF stand-alone group and 17 patients in the OLIF + PPSF group. The mean surgery duration, blood loss, and muscle damage in the OLIF stand-alone group were significantly better than those in the OLIF + PPSF group (P < 0.05). However, there was no significant difference in the average hospitalization time between the two groups (P > 0.05). There was no significant difference in the VAS and ODI scores between the two groups before surgery (P > 0.05), and VAS and ODI scores significantly improved after surgery (P < 0.05). The VAS and ODI scores in the OLIF stand-alone group were significantly better than those in the OLIF + PPSF group at 1 month (P < 0.05), While there was no significant difference between the two groups at 12 months and last follow up (P > 0.05). At the last follow-up, there was no significant difference in cage subsidence, fusion rate, ASD and complication rate between the two groups (P > 0.05).ConclusionOLIF stand-alone and OLIF + PPSF are both safe and effective in the treatment of DBP, and there is no significant difference in the long-term clinical and radiological outcomes. OLIF stand-alone has the advantages of surgery duration, blood loss, muscle damage, and early clinical effect. More clinical data are needed to confirm the effect of OLIF stand-alone on cage subsidence and ASD. This study provides a basis for the clinical application of standard DBP treatment with OLIF.

Analysis of rotational deformity correction by lateral lumbar interbody fusion with two-staged anterior-posterior combined corrective fusion surgery for adult degenerative kyphoscoliosis.

The present study is retrospective analysis of consecutively collected data. Lateral lumber interbody fusion (LLIF) is widely used in cases of adult spinal deformities. However, the corrective effects of LLIF cage insertion on the vertebral rotation deformity in the axial plane and the individual effects of LLIF and direct vertebral rotation (DVR) on rotational correction are unclear. To individually examine the corrective effects of LLIF and posterior corrective fusion surgery with direct DVR on vertebral rotation deformities in adult degenerative kyphoscoliosis. We analyzed 21 patients (5 males and 16 females) who underwent two-staged anterior-posterior combined corrective fusion surgery for adult degenerative kyphoscoliosis. Surgical time, blood loss, facet joint osteoarthritis (OA) grade, disc degeneration, cage height, vertebral rotational angle, and various X-ray parameters were investigated as evaluation items. The X-ray parameters showed significant postoperative improvements. The mean vertebral rotation angle was 6.4° ± 5.2° preoperatively, 3.5° ± 3.3° after LLIF (P = .014, vs preoperative), and 1.6° ± 1.7° after posterior corrective fusion surgery with DVR (P = .011, vs preoperative). Correlation analysis between the vertebral rotation angle and various measured values revealed that the vertebral rotation angle after LLIF was correlated with the cage height (r = −0.46, P = .032). The vertebral rotation angle after DVR was correlated with the facet joint OA grade (r = −0.49, P = .018) and the wedge angle after posterior corrective fusion surgery with DVR (R = 0.57, P = .006). We conclude that the effects of rotational deformity correction with LLIF cage insertion and additional posterior corrective fixation with DVR can be useful for correcting vertebral rotation deformities.

A Mechanistic Based Analysis of Clinicoradiological and Functional Outcome in C7-T1 Translational Injury

C7-T1 translational injuries are relatively rare, unstable, and usually associated with neurological impairment. We aim to analyze the C7-T1 translational injury based on Allen and Ferguson's classification and to highlight the clinicoradiologic and neurologic outcomes in these patients. Patients with C7-T1 translational injury were retrospectively analyzed and demographic data, mechanism, mode of injury, surgery details, and associated injuries were obtained. The initial neurologic status was recorded as American Spinal Injury Association (ASIA) grade. All the injuries were classified as per Allen and Ferguson classification and stage 4 compressive extension (CE) injury was further classified into stage 4a and stage 4b according to Rebich etal. Among 44 patients, the most common mechanism of injury was CE injury seen in 27 patients (61.4%) followed by distractive flexion (DF) in 16 patients (36.4%) and compressive flexion in 1 patient (2.2%). Neurologic deficit was noted in 14 of 27 patients (51.85%) with CE injury, which was less compared to 12 of 16 patients (75%) with DF injury. However, there was no significant difference in terms of neurologic recovery. One patient with standalone anterior fixation had implant loosening and underwent additional posterior fixation. We present the largest series of C7-T1 translational injuries in the literature to our best knowledge. CE injury is nearly 2 times more common than DF injury and is associated with a lower incidence of neurologic deficit and easier fracture reduction techniques. Staging the injury severity aids in better planning in terms of surgical approach and levels of fixation.

Anterior cervical corpectomy and fusion with stand-alone cages in patients with multilevel degenerative cervical spine disease is safe

BackgroundIn case of spinal cord compression behind the vertebral body, anterior cervical corpectomy and fusion (ACCF) proves to be a more feasible approach than cervical discectomy. The next step was the placement of an expandable titanium interbody in order to restore the vertebral height. The need for additional anterior plating with ACCF has been debatable and such technique has been evaluated by very few studies. The objective of the study is to evaluate radiographic and clinical outcomes in patients with multilevel degenerative cervical spine disease treated by stand-alone cages for anterior cervical corpectomy and fusion (ACCF).MethodsThirty-one patients (66.5 ± 9.75 years, range 53–85 years) were analyzed. Visual Analog Scale (VAS) and the 10-item Neck Disability Index (NDI) were assessed preoperatively and during follow-up on a regular basis after surgery and after one year at least. Assessment of radiographic fusion, subsidence, and lordosis measurement of Global cervical lordosis (GCL); fusion site lordosis (FSL); the anterior interbody space height (ant. DSH); the posterior interbody space height (post. DSH); the distance of the cage to the posterior wall of the vertebral body (CD) were done retrospectively. Mean clinical and radiographic follow-up was 20.0 ± 4.39 months.ResultsVAS-neck (p = 0.001) and VAS-arm (p < 0.001) improved from preoperatively to postoperatively. The NDI improved at the final follow-up (p < 0.001). Neither significant subsidence of the cages nor significant loss of lordotic correction were seen. All patients showed a radiographic union of the surgically addressed segments at the last follow up.ConclusionsApplication of a stand-alone expandable cage in the cervical spine after one or two-level ACCF without additional posterior fixation or anterior plating is a safe procedure that results in fusion. Neither significant subsidence of the cages nor significant loss of lordotic correction were seen.Trial registrationRetrospectively registered. According to the Decision of the ethics committee, Jena on 25th of July 2018, that this study doesn’t need any registration. https://www.laek-thueringen.de/aerzte/ethikkommission/registrierung/.

Comparative Finite Element Analysis of Fixation Techniques for APC II Open-Book Injuries of the Pelvis

Open-book fractures are defined as the separation of the pubic symphysis or fractures of the rami and disruption of the anterior sacroiliac, sacrotuberous, and sacrospinal ligaments. They can be stabilized by fixation of the anterior arch. However, indications and advantages of additional placement of iliosacral screws remain unknown. A CT-based model of the healthy pelvis was created and ligaments were modeled as tension springs. Range of motion of the sacroiliac joint and the pubic symphysis, and bone and implant stresses were compared for the physiological model, anterior symphyseal plating alone, and additional posterior fixation using two iliosacral screws. The range of motion of the sacroiliac joint was reduced for anterior symphyseal plating alone and further decrease was noted with additional posterior fixation. Von Mises stresses acting on the symphyseal plate were 819.7 MPa for anterior fixation only and 711.56 MPa for additional posterior fixation equivalent with a safety factor of 1.1 and 1.26, respectively. Implant stresses were highest parasymphyseal. While bone stresses exhibited a more homogeneous distribution in the model of the healthy pelvis and the model with anterior and posterior fixation, pure symphyseal plating resulted in bending at the pelvic rami. The analysis does not indicate the superiority of either anterior plating alone or additional posterior fixation. In both cases, the physiological range of motion of the sacroiliac joint is permanently limited, which should be taken into account with regard to implant removal or more flexible techniques for stabilization of the sacroiliac joint.

Characterization and rate of symptomatic adjacent-segment disease after index lateral lumbar interbody fusion: a single-institution, multisurgeon case series with long-term follow-up.

The rate of symptomatic adjacent-segment disease (ASD) after newer minimally invasive techniques, such as lateral lumbar interbody fusion (LLIF), is not known. This study aimed to assess the incidence of surgically significant ASD in adult patients who have undergone index LLIF and to identify any predictive factors. Patients who underwent index LLIF with or without additional posterior pedicle screw fixation between 2010 and 2012 and received a minimum of 2 years of postoperative follow-up were retrospectively included. Demographic and perioperative data were recorded, as well as radiographic data and immediate perioperative complications. The primary endpoint was revision surgery at the level above or below the previous construct, from which a survivorship model of patients with surgically significant symptomatic ASD was created. Sixty-seven patients with a total of 163 interbody levels were included in this analysis. In total, 17 (25.4%) patients developed surgically significant ASD and required additional surgery, with a mean ± SD time to revision of 3.59 ± 2.55 years. The mean annual rate of surgically significant ASD was 3.49% over 7.27 years, which was the average follow-up. One-third of patients developed significant disease within 2 years of index surgery, and 1 patient required surgery at the adjacent level within 1 year. Constructs spanning 3 or fewer interbody levels were significantly associated with increased risk of surgically significant ASD; however, instrument termination at the thoracolumbar junction did not increase this risk. Surgically significant ASD was not impacted by preoperative disc height, foraminal area at the adjacent levels, or changes in global or segmental lumbar lordosis. The risk of surgically significant ASD after LLIF was similar to the previously reported rates of other minimally invasive spine procedures. Patients with shorter constructs had higher rates of subsequent ASD.

Posterior fixation can further improve the segmental alignment of lumbar degenerative spondylolisthesis with oblique lumbar interbody fusion

BackgroundFor patients with degenerative spondylolisthesis, whether additional posterior fixation can further improve segmental alignment is unknown, compared with stand-alone cage insertion in oblique lumbar interbody fusion (OLIF) procedure. The aim of this study was to compare changes of the radiographical segmental alignment following stand-alone cage insertion and additional posterior fixation in the same procedure setting of OLIF for patients with degenerative spondylolisthesis.MethodsA retrospective observational study. Selected consecutive patients with degenerative spondylolisthesis underwent OLIF procedure from July 2017 to August 2019. Five radiographic parameters of disc height (DH), DH-Anterior, DH-Posterior, slip ratio and segmental lordosis (SL) were measured on preoperative CT scans and intraoperative fluoroscopic images. Comparisons of those radiographic parameters prior to cage insertion, following cage insertion and following posterior fixation were performed.ResultsA total of thirty-three patients including six males and twenty-seven females, with an average age of 66.9 ± 8.7 years, were reviewed. Totally thirty-six slipped levels were assessed with thirty levels at L4/5, four at L3/4 and two at L2/3. Intraoperatively, with only anterior cage support, DH was increased from 8.2 ± 1.6 mm to 11.8 ± 1.7 mm (p < 0.001), DH-Anterior was increased from 9.6 ± 2.3 mm to 13.4 ± 2.1 mm (p < 0.001), DH-Posterior was increased from 6.1 ± 1.9 mm to 9.1 ± 2.1 mm (p < 0.001), the slip ratio was reduced from 11.1 ± 4.6% to 8.3 ± 4.4% (p = 0.020) with the slip reduction ratio 25.6 ± 32.3%, and SL was slightly changed from 8.7 ± 3.7° to 8.3 ± 3.0°(p = 1.000). Following posterior fixation, the DH was unchanged (from 11.8 ± 1.7 mm to 11.8 ± 2.3 mm, p = 1.000), DH-Anterior and DH-Posterior were slightly changed from 13.4 ± 2.1 mm and 9.1 ± 2.1 mm to 13.7 ± 2.3 mm and 8.4 ± 1.8 mm respectively (P = 0.861, P = 0.254), the slip ratio was reduced from 8.3 ± 4.4% to 2.1 ± 3.6% (p < 0.001) with the slip reduction ratio 57.9 ± 43.9%, and the SL was increased from 8.3 ± 3.0° to 10.7 ± 3.6° (p = 0.008).ConclusionsCompared with stand-alone cage insertion, additional posterior fixation provides better segmental alignment improvement in terms of slip reduction and segmental lordosis in OLIF procedures in the treatment of lumbar degenerative spondylolisthesis.

Anterior Cervical Corpectomy and Fusion for Degenerative and Traumatic Spine Disorders, Single-Center Experience of a Case Series of 119 Patients.

BACKGROUNDAnterior cervical corpectomy and fusion (ACCF) is a treatment option for several cervical pathologies. Various graft materials such as autografts, titanium mesh cages (TMC), or poly-ether-ether-ketone (PEEK) cages are used. Additional posterior fixation (PF) to provide extra support and improve stability is sometimes performed initially, or later as supplementary treatment.OBJECTIVETo describe our retrospective study of 119 consecutive cases of ACCF with synthetic grafts, in 3 cohorts of cervical spondylotic myelopathy (CSM), infectious and neoplastic processes, and trauma, with special focus on need for supplementary PF.METHODSA total of 135 adult patients treated with ACCF between January 2005 and January 2018 were identified. Patients lost to follow-up were excluded, and 119 remaining patients were included for retrospective clinical and radiological assessment.RESULTSSynthetic grafts were used in 116 (97%) cases. Only 9 (8%) ACCF cases required later supplementary PF, where 7 (78%) cases were multilevel. There was a statistically significant difference in revision rate with PF for single-level compared to multilevel ACCFs (P = .001). Revision rates with PF were 2%, 29%, and 7% in CSM, infectious and neoplastic processes, and trauma cohorts, respectively.CONCLUSIONThe results indicate that ACCF is a safe and effective treatment for degenerative and traumatic cervical spine disorders, with low complication and revision rates. Single-level ACCF can be performed without additional PF. Multilevel ACCF (n > 2) and pathologies affecting bone quality seem to be risk factors for material subsidence and instability. In these cases, additional PF should be considered.

When is the circumferential stabilization necessary for subaxial cervical fracture dislocations? The posterior ligament-bone injury classification and severity score: a novel treatment algorithm.

To propose a novel classification and scoring system called the posterior ligament-bone injury classification and severity score (PLICS) that offers a quantitative score to guide the need for posterior stabilization in addition to anterior reconstruction for subaxial cervical fracture dislocations (SCFDs). A total of 456 patients with SCFDs were prospectively included. Patients with PLICS ≥ 7 together with extremely unstable lateral mass fracture (EULMF) were classified as high-risk group, and the other patients were classified as low-risk group. For patients in the low-risk group, anterior-only reconstruction was performed; for patients in the high-risk group, additional posterior lateral mass fixation and fusion was performed after anterior reconstruction. Clinical outcome evaluation included using the visual analogue score (VAS), the Neck Disability Index (NDI), and the American Spinal Injury Association (ASIA) impairment scale. The change in the local sagittal alignment kyphosis Cobb angle was also recorded. A total of 370 patients (81.1%) completed the minimal 12-month follow-ups, including 321 patients of low-risk group and 49 patients of high-risk group. Compared with the average VAS score preoperatively, the score at 12-month follow-up was significantly improved (from 6.1 + 0.3 to 1.1 + 0.2 in the low-risk group, P < 0.001; from 6.4 + 0.2 to 1.4 + 0.2 in the high-risk group, P < 0.001). The average NDI score at the 12-month follow-up was statistically low in the low-risk group (8.8 + 2.5 vs 13.8 + 3.4, P = 0.034). At least more than one grade improvement in the ASIA scale was observed in 80.5% of all patients. The local kyphosis Cobb angle at the injured segment averaged improved in both groups. A PLICS score ≥ 7 together with EULMF can be the threshold for posterior stabilization in addition to anterior reconstruction for the patients with SCFDs.

Treatment of Spontaneous Adult Thoracolumbar Spondylodiscitis With Interbody Fusion Using Autogenous Bone from Decorticated Spinous Process Supplanted with Posterolateral Transpedicular Rod-Screw Fixation

Abstract Background: Spontaneous spondylodiscitis, although rare, but carries the risk of developing neurological impairment. Aim of Study: We aim at introducing our experience with the treatment of spontaneous adult spondylodiscitis with interbody fusion using autogenous bone from decorticated spinous process supplanted with posterolateral transpedicular rod-screw fixation at the Neurosurgery Department of Benha University Hospital between January 2015 and November 2019. Patients and Methods: Between January 2015 and No-vember 2019, among 51 patients who were diagnosed with pyogenic thoracolumbar spondylodiscitis, 12 patients (8 males and 4 females) underwent curettage, drainage and interbody fusion using autogenous bone from the removed spinous process augmented with transpedicular rod-screw fixation. Results: All patients, but one, showed improvement of their preoperative pain and the level of inflammatory markers in the blood. This patient was diagnosed as having screw pull-out and needed surgical reinsertion with a larger screw. Conclusions: Lumbar interbody fusion using autogenous bone from decorticated spinous process supplanted with posterolateral transpedicular rod-screw fixation represents a reasonable substitute to the traditional anterior curettage, stabilization with additional posterior rod-screw fixation for the treatment of spontaneous lumbar spondylodiscitis.

The Anterior Transarticular Fixation of C1/C2 in the Elderly With Dens Fractures.

Anterior transarticular screw fixation (ATSF) of C1/C2 can be used for the treatment of unstable dens fractures. Here, we evaluated the feasibility of an anterior C1/C2 fixation in elderly patients with unstable dens fractures. Furthermore, we tried to analyze safe entry zones for ATSF surgery. A consecutive cohort of 13 patients with unstable dens fractures were treated with ATSF of C1/C2 between January 2015 and October 2016. If necessary, an additional screw was placed into the odontoid process. The placement was radiographically analyzed using the 3D Arcadis Orbic (Siemens, Erlangen, Germany). Additionally, computed tomography scans of the cervical spine from 50 trauma patients were analyzed to evaluate safe entry zones for anterior odontoid screw fixation and for ATSF. ATSF was performed in 13 cases (7 female, 6 male; mean age 81.80 years). One screw had to be corrected intraoperatively due to initial malplacement. Neurological deficits or an injury of the vertebral artery were not observed. All patients suffered from swallowing difficulties during the postoperative course, without lesions of the esophagus or the trachea. In 4 patients (30.8%), an additional posterior fixation was offered to the patients due to progressive loosening of the screws.The anatomical-radiographic analyzes revealed a significantly shallower angle of trajectory for anterior odontoid screw fixation (24.9° ± 5.85°) than for ATSF (39.1° ± 6.44° (left); 40.5° ± 6.79° (right) P = 0.02). The ATSF of C1/C2 might be a valuable option in the treatment of instable C1/C2 fractures, especially in the elderly or in patients with short necks and/or high body mass index due to the steeper trajectory compared with odontoid screw placement. Yet available screws seem to be of inferior resistance compared with the biomechanical properties of a dorsal fixation. Further studies should focus on screws with better mechanical properties and probably additional cement augmentation. 4.

6. Biomechanical investigation of the potential development and prevention of scoliosis following various sizes of chest wall resection

BACKGROUND CONTEXT Chest wall resection is used to treat several thoracic disorders including tumor removals. A well-known problematic sequela of chest wall resections is development of scoliosis. Literature shows that the degree of the induced curvature correlates to the number of resected ribs. Despite the seriousness and frequency of scoliosis following chest well resection, the etiology and biomechanical information needed to understand this deformity development are not well-known. PURPOSE The objective of the present study was to investigate the effect of chest wall resections, ranging in size from 1 to 6 ribs, on the biomechanical stability of the spine. Further, the study compared anterior-only fixation with a combined anterior-posterior approach in reducing range of motion (ROM) following chest wall resection. STUDY DESIGN/SETTING Biomechanics/laboratory. METHODS The range of motion (ROM) of six specimens (C7–L2) was captured using a custom-built six degrees-of-freedom machine in each of three physiological rotation axes: flexion extension (FE), lateral bending (LB), and axial rotation (AR). Left posterior ribs were sequentially resected 7 cm from the rib head, starting at the 5th rib and continuing until the 10th rib. Injured specimens were instrumented first with unilateral anterior rod fixation (UA) and then with additional unilateral posterior fixation (UA+UP), each starting at T4 and then extended distally as ribs were resected. Relative motion between the proximal and distal ends of the construct was measured in all three axes for the intact, injured, UA, and UA+UP constructs. RESULTS Raw ROM of the injured specimen increased in a stepwise manner as additional ribs were resected, with an average increase of 0.90°±0.52° in FE, 0.98°±0.40° in LB, and 2.75°±1.50° in AR. No statistically significant differences in ROM normalized to the intact specimen were found between operative constructs for any injury size (p>.05). Across all injury sizes, the UA construct reduced motion, and the UA+UP construct further reduced motion in all FE (22.0±12.3% vs 58.4±13.2%), LB (51.0±9.8% vs 74.4±9.0%), and AR (25.4±9.0% vs 58.7±11.2%). The impact of fixation was slightly greater as more ribs were resected. CONCLUSIONS The stepwise ROM increase for the injured model as more ribs were resected can likely be attributed to the additional motion segment, suggesting that the etiology of scoliosis following chest wall resection may not be purely biomechanical in nature. Overall, the UA+UP construct may be a more optimal construct than UA in reducing motion and potentially assisting in limiting the risk of scoliosis development. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Clinical and radiological outcomes in thoracolumbar fractures using the SpineJack device. A prospective study of seventy-four patients with a two point three year mean of follow-up.

The aim of this study was to assess clinical and radiological results of SpineJack on the treatment of vertebral body fractures in a continuous prospective series of patients. Between May 2012 and April 2015, all patients operated using the SpineJack device were prospectively included in this monocentric study. Demographic data, clinical, and radiological results were recorded. Complications and surgical managements were recorded. At a mean follow-up of 2.3years, 74 patients with 77 fractured vertebrae were included. The stand-alone SpineJack group comprised 60 patients with 63 fractured vertebrae (group 1) and the group with additional posterior fixation 14 patients with 14 fractured vertebrae (group 2). The average initial vertebral wedge angle was 13.3 ± 6.1 degrees for group 1 and 15.3 ± 5.7 degrees for group 2 (p = 0.25). Post-operative values were 6.5 ± 4.6 degrees for group 1 and 5.1 ± 3.9 degrees for group 2 (p = 0.31). The differences within the same group were highly significant (p < 0.0005). The loss of reduction at last follow-up was 0.8 ± 1.6 degrees in group 1 and 0.6 ± 2.0 degrees in group 2 (p = 0.77). Subjective results were considered as very good or good for 57 patients (95%) in group 1 and for 11 patients (79%) in group 2, p = 0.07. The SpineJack seems to be a promising tool in the treatment of traumatic vertebral fractures with a correction in the sagittal plane comparable with what can be found in the literature.

Stent Screw−Assisted Internal Fixation (SAIF) of Severe Lytic Spinal Metastases: A Comparative Finite Element Analysis of the SAIF Technique

A new stent-screw-assisted internal fixation (SAIF) minimally invasive cement-augmentation technique has been introduced to treat patients with extreme osteolytic lesions of the vertebral body. The aim of the current finite element study, employing a spine model with an extreme osteolytic defect, was to assess the effect of the SAIF technique in reducing strains in the vertebral body in comparison with a standard surgical short posterior fixation. Different finite element models of a L1-S1 spine were developed, representing an intact condition (reference configuration), an extreme osteolysis condition, and its treatment, respectively with stand-alone SAIF, SAIF and posterior fixation, and with stand-alone posterior fixation. Each model was loaded to reproduce standing and upper body bending. Principal strains were calculated on the superior endplate, anterior and posterior cortical walls. A paired Wilcoxon test with a 0.05 significance level was performed to statistically analyze the results. Median strains on the bony structures increased in the osteolysis model compared with the intact model, and the SAIF technique was effective in reducing such strains under both standing and flexion conditions. Additional posterior fixation, combined with the SAIF technique, produced minimal further reduction of the median strains on the bony structures. Stand-alone posterior fixation only shielded the osteolytic vertebra avoiding excessive displacements but failed in restoring the axial stiffness to values typical of the intact vertebra. The new SAIF technique resulted effective in restoring the load-bearing capacity of the extensively osteolytic vertebra; additional posterior fixation provided only further minor advantages.

Anterior cervical spine surgery for the treatment of subaxial cervical spondylodiscitis: a report of 30 consecutive patients.

OBJECTIVEInfection of the cervical spine is a rare disease but is associated with significant risk of neurological deterioration, morbidity, and a poor response to nonsurgical management. The ideal treatment for cervical spondylodiscitis (CSD) remains unclear.METHODSHospital records of patients who underwent acute surgical management for CSD were reviewed. Information about preoperative neurological status, surgical treatment, peri- and postoperative processes, antibiotic treatment, repeated procedure, and neurological status at follow-up examination were analyzed.RESULTSA total of 30 consecutive patients (17 male and 13 female) were included in this retrospective study. The mean age at procedures was 68.1 years (range 50-82 years), with mean of 6 coexisting comorbidities. Preoperatively neck pain was noted in 21 patients (70.0%), arm pain in 12 (40.0%), a paresis in 12 (40.0%), sensory deficit in 8 (26.7%), tetraparesis in 6 (20%), a septicemia in 4 (13.3%). Preoperative MRI scan revealed a CSD in one-level fusion in 21 patients (70.0%), in two-level fusions in 7 patients (23.3%), and in three-level fusions in 2 patients (6.7%). In 16 patients an antibiotic treatment was initiated prior to surgical treatment. Anterior cervical discectomy and fusion with cervical plating (ACDF+CP) was performed in 17 patients and anterior cervical corpectomy and fusion (ACCF) in 12 patients. Additional posterior decompression was performed in one case of ACDF+CP and additional posterior fixation in ten cases of ACCF procedures. Three patients died due to multiple organ failure (10%). Revision surgery was performed in 6 patients (20.7%) within the first 2 weeks postoperatively. All patients received antibiotic treatment for 6 weeks. At the first follow-up (mean 3 month) no recurrent infection was detected on blood workup and MRI scans. At final follow-up (mean 18 month), all patients reported improvement of neck pain, all but one patients were free of radicular pain and had no sensory deficits, and all patients showed improvement of motor strength. One patient with preoperative tetraparesis was able to ambulate.CONCLUSIONSCSD is a disease that is associated with severe neurological deterioration. Anterior cervical surgery with radical debridement and appropriate antibiotic treatment achieves complete healing. Anterior cervical plating with the use of polyetheretherketone cages has no negative effect of the healing process. Posterior fixation is recommended following ACCF procedures.

Hollow modular anchorage (HMA) screws for anterior transvertebral fixation in high-grade spondylolisthesis cases requiring 360 degrees in-situ fusion

Objective: 360 degrees in-situ fusion for high-grade spondylolisthesis showed satisfying clinical long-term results. Combining anterior with posterior surgery increases fusion rates. Anteriorly inserted transvertebral HMA screws could be an alternative to strut graft constructs or cages, avoiding donor site complications. In addition, complete posterior muscle detachment is avoided and the injury risk of neural structures is minimized. This study investigates the use of HMA screws in this context.Material and methods: Five consecutive patients requiring L4-S1 in-situ fusion for isthmic spondylolisthesis (four Grade 3 and one Grade 4) were included. The L5/S1 level was fused with an HMA screw filled with local bone and bone morphogenic protein (BMP2), inserted via the L4/5 disc space level. An L4/5 stand-alone interbody fusion with additional minimal invasive posterior screw fixation was added.Results: Transvertebral insertion of the HMA device was accomplished via a retroperitoneal approach to L4/L5 in all cases without exposure of L5/S1. Blood loss ranged from 150 ml–350 ml. No intraoperative complication occurred. One patient developed posterior wound infection requiring debridement. Solid fusion was confirmed with a CT scan after 6 months in all patients. All patients improved to unrestricted activities of daily living with two being limited by occasional back pain.Conclusions: HMA screws allow for effective lumbosacral fusion via a limited anterior exposure. This is technically easier than posterior exposure of the lumbosacral junction in high-grade spondylolisthesis requiring 360 degrees fusion.

Effect of three-dimensional rotational deformity correction in surgery for adult degenerative scoliosis using lumbar lateral interbody fusion and posterior pedicle screw fixation.

Introduction Corrective surgery for adult degenerative scoliosis using lateral interbody fusion (LIF) and additional posterior fixation is an efficient procedure. However, it is unclear how this procedure affects rotational deformity correction. Therefore, the goal of the present study was to use three-dimensional (3D) images, taken during surgery, to investigate rotational deformity correction in the treatment of adult degenerative scoliosis using LIF and posterior fixation using a pedicle screw system. Methods The subjects were 12 females who were treated using LIF and posterior fixation for adult degenerative scoliosis. The patients had a mean age of 72 (65-76) years. 3D images were acquired before surgery, after LIF, and after additional posterior fixation. Rotational angles of the upper vertebra with respect to the lower vertebra of each fixed segment were measured in 3 planes. Correction factors for rotational deformity were investigated after LIF and additional posterior fixation. Results There were significant improvements in radiographical parameters for global spinal balance. The correction angles per segment were 4.7° for lateral bending, 6.9° for lordosis, and 4.5° for axial rotation. LIF was responsible for correction of four-fifths of lateral bending and axial rotation, and two-thirds of lordotic changes. Conclusions Lateral bending, axial rotational deformities, and lordosis were primarily corrected by LIF. Further lordosis correction was achieved using additional posterior fixation. These results indicate that corrective surgery for adult degenerative scoliosis using these procedures is effective for rotational deformity correction and leads to an ideal global spinal alignment.

Biomechanical evaluation of a novel integrated artificial axis: A finite element study.

Various modified instruments are used for the anterior reconstruction of the tumor lesion affecting the second cervical vertebra, but there have been no reports regarding individual integrated artificial axis (IAA) prosthesis fabricated by selective laser melting. In the present work, a new type of IAA prosthesis has been designed with a 3-dimensional (3D) finite element model of normal occiput-the fourth cervical vertebra being established to assess its biomechanics. For easy comparison, another 3D finite element model is also established for the T-shaped Harms cage and an additional posterior fixation was performed on each model. The models are tested under a preliminary loading of 40 N to simulate cervical physical action including flexion, extension, lateral bending, and rotation. Under various loads from 4 different directions, the maximum stress and displacement of the IAA are less than those of the modified T-shaped Harms cage. Except for flexion, the maximum stress of the third cervical vertebra endplate of the IAA is smaller than that of the modified T-shaped Harms cage. The new prosthesis with axis is a good choice for upper cervical operation, which not only can greatly increase the operation stability of the upper cervical segment but also could significantly reduce the risk of fixation failure due to Harms cage subsidence.

Rationale and complications of the anterior-lateral extrapleural retroperitoneal approach for unstable thoracolumbar fractures: Experience in 86 consecutive patients

ObjectivesTo describe the rationale, pros and cons, and complications of the anterior-lateral extrapleural retroperitoneal approach for unstable (TLICS>4) thoracolumbar fractures. Patients and methodsClinical and radiological data and outcomes from a cohort treated surgically via said approach were retrospectively reviewed. All patients were operated on exclusively by 5 neurosurgeons trained in spine surgery. ResultsBetween June 1999 and December 2015, 86 patients underwent surgery (median age 42 years, most common level: L1). Approximately 32.5% presented with a preoperative neurological defect. After surgery (mean duration: 275min), 75.6% presented with no neurological sequelae and only one-third required blood transfusion. Median postoperative stay was 7 days. Correction of kyphosis was considered adequate and suboptimal but acceptable in 91% and 9% of the patients, respectively. Complications occurred in 36 patients, the majority being transient. We observed failure of the construct in 2 cases (collapse of an expandable cage and extrusion of a locking screw). No infections, vascular or visceral lesions, permanent neurological worsening or mortality occurred during hospitalisation. One patient ultimately needed additional posterior fixation due to persistence of pain. Median follow-up was 252days (27.9% was lost to follow-up). ConclusionsThe extrapleural extraperitoneal approach provides solid anterior reconstruction, allows wide decompression of the spinal canal, and permits adequate and long-lasting correction of kyphosis. The rates of infection, construct failure, need for reoperation and vascular or visceral lesions are minimal.