Examination of the Pediatric Cervical Spine Under Anesthesia.

Cervical spine injuries in pediatric patients can have devastating consequences if not properly diagnosed. The standard workup for suspected cervical spine injuries includes cervical X-rays and a high-resolution CT. If suspicion still exists then a cervical MRI is obtained. When the cervical MRI shows ligamentous edema but is unable to determine the integrity of the ligaments then additional workup is needed. Often a flexion and extension lateral cervical X-ray can help determine ligament integrity in the non-sedated cooperative age-appropriate patient. For pediatric patients who are unable to perform the flexion and extension X-ray, we perform a dynamic fluoroscopic examination of the cervical spine under anesthesia. The patient is positioned in the supine position. The C-arm is positioned in the lateral position. The surgeon manually performs distraction, flexion, extension, and translation maneuvers while obtaining live fluoroscopy and assessing for signs of cervical instability. If cervical instability exists then the appropriate definitive treatment can be performed. If the cervical spine is stable then cervical immobilization can be discontinued.

Adolescent idiopathic scoliosis with concomitant spondylolysis: choice of fusion levels and evaluation of the outcomes obtained leaving the lytic level not instrumented.

PURPOSE: 7% of adolescent idiopathic scoliosis (AIS) patients also present with a pars defect. To date, there are no available data on the results of fusion ending proximal to a spondylolysis in the setting of AIS. The aim of this study was to analyze the outcomes of posterior spinal fusion (PSF) in this patient cohort, to investigate if maintaining the lytic segment unfused represents a safe option. METHODS: Retrospective review of all patients who received PSF for AIS, presented with a spondylolysis or spondylolisthesis and had a min. 2-year follow-up. Demographic data, instrumented levels, and preoperative radiographic data were collected. Mechanical complications, coronal or sagittal parameters, amount of slippage, and pain levels were evaluated. RESULTS: Data from 22 patients were available (age 14.4 ± 2.5 years), 18 Lenke 1-2 and 4 Lenke 3-6. 5 patients (24%) had an isthmic spondylolisthesis, all Meyerding I. The mean preoperative Cobb angle of the instrumented curves was 58 ± 13°. For 18 patients, the lowest instrumented vertebra (LIV) was the last touched vertebra (LTV); for 2, LIV was distal to the LTV; for 2, LIV was one level proximal to the LTV. The number of segments between the LIV and the lytic vertebra ranged from 1 to 6. At the last follow-up, no complications were observed. The residual curve below the instrumentation measured 8.5 ± 6.4°, the lordosis below the instrumented levels was 51.4 ± 13°. The magnitude of the isthmic spondylolisthesis remained constant for all included patients. Three patients reported minimal occasional low back pain. CONCLUSION: The LTV can be safely used as LIV when performing PSF for the management of AIS in patients with L5 spondylolysis.

Risk factors for distal construct failure in posterior spinal instrumented fusion for adolescent idiopathic scoliosis: a retrospective cohort study.

PURPOSE: To evaluate risk factors for distal construct failure (DCF) in posterior spinal instrumented fusion (PSIF) in adolescent idiopathic scoliosis (AIS). We hypothesise increased inferior angulation of the pedicle screw in the lowest instrumented vertebra (LIV) predisposes to failure and aim to find the critical angle that predisposes to failure. METHODS: A retrospective cohort study was performed on all patients who underwent PSIF for AIS at our institution from 2010 to 2020. On lateral radiographs, the angle between the superior endplate of the LIV was measured against its pedicle screw trajectory. Data on demographics, Cobb angle, Lenke classification, instrumentation density, rod protrusion from the most inferior screw, implants and reasons for revision were collected. RESULTS: Of 256 patients, 9 patients had DCF with 3 further failures post-revision, giving 12 cases to analyse. The DCF rate was 4.6%. The mean trajectory angle of DCF patients compared to non-DCF was 13.3° (95% CI 9.2° to 17.4°) vs. 7.6° (7.0° to 8.2°), p = 0.0002. The critical angle is less than 11° (p = 0.0076), OR 5.15. Lenke 5 and C curves, lower preoperative Cobb angle, titanium only rod constructs and one surgeon had higher failure rates. 9.6% of rods protruding less than 3 mm from its distal screw disengaged. CONCLUSION: Increased inferior trajectory of the LIV screw increases the rate of DCF; inferior trajectory greater than 11° predisposes to failure. Rod protrusion less than 3 mm from the distal screw increases rate of disengagement. LEVEL OF EVIDENCE: III.

A microbiology study on the wounds of pediatric patients undergoing spinal fusion for scoliosis.

PURPOSE: Surgical site infection is a significant complication in posterior spinal fusion for scoliosis in pediatric and adolescent patients. Current literature demonstrates a lack of consensus regarding best prophylactic systemic and topical antibiotic regimens for reducing infection rates. This study aims to identify which common microbes are present at particular locations in the spine, and whether these are covered by our current systemic and topical antibiotic prophylaxis regimens. METHODS: A prospective observational study at a National Children's Hospital was conducted on 21 consecutive patients who underwent elective surgery for spinal deformity. Swabs were taken from four layers of the spine, including the superficial skin surface at the start of the case (after surgical site preparation with povidone-iodine), the deep dermis, and the deep surgical bed at the end of exposure and again after the corrective maneuver prior to closure. At each layer, swabs were taken from the proximal, middle, and distal portion of the wound. Swabs were sent to the laboratory for culture and susceptibility testing. RESULTS: Thirteen (62%) of patients had positive microbial growth. Two microbes were identified, Staphylococcus epidermidis (9.5% of patients) and Cutibacterium acnes (Propionibacterium acnes) (52% of patients). 100% of these microbes were sensitive to cefazolin and vancomycin. 3% of patients had positive growth at the skin layer, 32% positive at the dermal layer, 17% positive after exposure, and 40% positive at the conclusion of the case (p = 0.006). No difference was observed in microbial presence in the upper thoracic, lower thoracic and lumbar spine. CONCLUSION: Despite adequate surgical site preparation and sterile procedure, microbial contamination remains abundant in the dermal layer and deeper in the spinal wound throughout the case.

Lordosis loss in degenerative spinal conditions.

PURPOSE: To establish whether common degenerative lumbar spine conditions have a predictable sagittal profile and associated range of lordosis. The spinopelvic balance of a normal population and normal ranges are well described in the literature. There is also evidence that certain degenerative conditions can lead to a preponderance of loss of lordosis at specific spinal levels. There is limited literature on the range and magnitude of loss of lordosis for known degenerative lumbar spine pathologies. METHODS: A retrospective analysis of prospectively obtained radiographs from a dual surgeon database was performed and imaging analysed for spinopelvic parameters. Degenerative conditions studied were; Lumbar degenerative spondylolisthesis (L3/4 and L4/5 analysed separately), L5/S1 degenerative disc disease, L5/S1 isthmic spondylolisthesis. Pelvic incidence, sacral slope, pelvic tilt, segmental and global lumbar lordosis, vertebral lordosis and lumbar vertical axis were measured. RESULTS: The range of change in segmental lordosis was normally distributed for all studied degenerative spinal conditions except L5/S1 isthmic spondylolisthesis. L5/S1 degenerative disc disease affected younger adults (mean age 37), whilst degenerative spondylolisthesis at L3/4 and L4/5 affected older adults (mean ages 69.5 and 68.9 respectively). Removing an outlying high-grade L5/S1 isthmic spondylolisthesis made the data distribution approach a normal distribution. CONCLUSION: Most degenerative spinal pathologies cause a normally distributed spectrum of deformity which should be addressed and corrected with a tailored, individualised surgical plan for each patient. Universal treatment recommendations should be interpreted with caution.

Range of motion, sacral screw and rod strain in long posterior spinal constructs: a biomechanical comparison between S2 alar iliac screws with traditional fixation strategies.

BACKGROUND: S1 screw failure and L5/S1 non-union are issues with long fusions to S1. Improved construct stiffness and S1 screw offloading can help avoid this. S2AI screws have shown to provide similar stiffness to iliac screws when added to L3-S1 constructs. We sought to examine and compare the biomechanical effects on an L2-S1 pedicle screw construct of adding S2AI screws, AxiaLIF, L5-S1 interbody support via transforaminal lumbar interbody fusion (TLIF), and to examine the effect of the addition of cross connectors to each of these constructs. METHODS: Two S1 screws and one rod with strain gauges (at L5/S1) were used in L2-S1 screw-rod constructs in 7 L1-pelvis specimens (two with low BMD). ROM, S1 screw and rod strain were assessed using a pure-moment flexibility testing protocol. Specimens were tested intact, and then in five instrumentation states consisting of: (I) Pedicle screws (PS) L2-S1; (II) PS + S2AI screws; (III) PS + TLIF L5/S1; (IV) PS + AxiaLIF L5/S1; (V) PS + S2AI + AxiaLIF L5/S1. The five instrumentation conditions were also tested with crosslinks at L2/3 and S1/2. Tests were conducted in flexion-extension, lateral bending and axial torsion with no compressive preload. RESULTS: S2A1 produces reduced S1 screw strain for flexion-extension, lateral bending and axial torsion, as well as reduced rod strain in lateral bending and axial torsion in comparison to AxiaLIF and interbody instrumentation, at the expense of increased rod flexion-extension strain. Cross-connectors may have a role in further reduction of S1 screw and rod strain. CONCLUSIONS: From a biomechanical standpoint, the use of the S2AI technique is at least equivalent to traditional iliac screws, but offers lower prominence and ease of assembly compared to conventional sacroiliac stabilization.

Recurrent aneurysmal bone cyst of the cervical spine in childhood treated with doxycycline injection.

A 12-year-old female was treated surgically for an aneurysmal bone cyst of the cervical spine involving the C2 and C3 vertebrae. The patient underwent surgery twice and further surgery was assessed as unfeasible. Treatment by intraosseous injection of doxycycline was uncomplicated and has resulted in resolution of the multifocal recurrent disease.