Correction of Thoracic Hypokyphosis in Adolescent Scoliosis Using Patient-Specific Rod Templating.

The emphasis of surgical correction in adolescent idiopathic scoliosis (AIS) has been given to coronal plane correction of deformity without addressing the sagittal plane thoracic hypokyphosis. Thoracic hypokyphosis has been implicated in cervical malalignment, increased incidence of proximal and distal junctional kyphosis, spinopelvic incongruence, and increased incidence of low back pain. The surgeon, variability in surgical technique, and difference in rod contouring have been implicated as factors resulting in less-than-adequate restoration of thoracic kyphosis. We hypothesised that predictable correction of hypokyphosis could be achieved by using a reproducible surgical technique with patient-specific rod templating. We describe a technique of correction of AIS with dual differential rod contouring (DDC) using patient-specific rod templating to guide intraoperative rod contouring. The pre- and post-operative radiographs of 61 patients treated using this technique were reviewed to compare correction of hypokyphosis achieved with that predicted. Analysis revealed that we achieved a kyphosis within +/- 5.5 of the predicted value. The majority of patients had a post-operative kyphosis within the optimal range of 20-40 degrees. We concluded that patient-specific rod templating in DDC helps surgeons to consistently achieve sagittal correction in AIS close to a predicted value while achieving a very good coronal plane correction.

Does Instrumentation of the Fractured Level in Thoracolumbar Fixation Affect the Functional and Radiological Outcome?

STUDY DESIGN: Retrospective comparative study. OBJECTIVES: To compare radiological and functional outcomes of patients with fixation constructs utilizing pedicle screw stabilization at the fracture level (FL group) versus patients with non-fracture level (NFL group) fixation in single level fractures of the thoracolumbar junction (T11-L1). METHODS: 53 patients of whom fracture level screw was used in 34 (FL group) were compared to 19 patients in NFL group. Radiological parameters analyzed were sagittal index, bi-segmental kyphosis (Cobb) angle and degree of vertebral height restoration. Prospectively collected patient reported functional outcomes and post-operative complications were also studied. Stepwise regression analysis adjusted by age, gender and functional scores was performed to account for the small numbers and unequal sizes of the groups. RESULTS: Back pain score was significantly lower in the FL group (P < 0.025). Core Outcome Measures Index scores and leg pain scores, though low in the FL group, were not statistically significant. The regression analysis showed that the inclusion of the fracture-level screw was independently associated with a greater change in sagittal index and vertebral height restoration post-operatively. Sagittal index was maintained through to final follow up as well. The bi-segmental Cobb's angle correction was not associated with fracture-level screw construct. There was no significant difference between the groups for revision surgery, deep infection, implant failure or length of hospital stay. CONCLUSION: The inclusion of the fracture-level pedicle screws in the fixation construct significantly improves the immediate and final measured radiological parameters, with improved functional scores in single level unstable vertebral fractures of the thoracolumbar junction.

Revision pedicle screws with impaction bone grafting: a case series.

BACKGROUND: Pedicle screw fixation in spinal constructs can be subject to failure requiring revision surgery. In cases of aseptic loosening various salvage techniques have been described. Revision screws augmented with cement have become popular but are not without risks. Larger diameter screws are often used but result in reducing bone stock or expanding the pedicles. We present a novel technique of pedicle screw revision by impaction bone allografting and a case series. METHODS: The failed screws are removed. The screw track is probed to check its integrity. Milled bone allograft is funneled into the screw hole and sequentially impacted, before insertion of a replacement screw. We report a case series and describe a single case where this method has been used. Information was gathered from the electronic patient record in our hospital. RESULTS: Ten screws were revised in 7 patients. Mean age at first surgery was 60.86 (48-76) years. Average time between first surgery and revision was 12.6 (4.7-49.9) months. Average follow-up was 26.2 (5.7-62.2) months and no screws showed any signs of loosening. CONCLUSIONS: Impaction grafting with bone allograft is a technique for pedicle screw salvage that can be used safely and effectively as an alternative to cemented screws, when pedicle screws have failed by aseptic loosening. It avoids the risks associated with cemented screws and in our series was successful.

Drug Reaction, Eosinophilia, and Systemic Symptoms (DRESS) Syndrome As a Mimicker of Spinal Infection: Awareness for Spinal Surgeons.

Drug reaction, eosinophilia, and systemic symptoms (DRESS) syndrome is a delayed severe drug hypersensitivity (type IVb) syndrome with cutaneous eruption, hematological abnormalities, and multi-organ involvement. The wide spectrum of the disease manifestations, long-term sequelae, and high mortality rates are a clinical concern. Though not commonly reported in spinal surgery patients, the use of long-term antibiotics is a potential causative agent in spinal infections. DRESS syndrome can mimic systemic spinal infections, and clinical diagnosis requires high awareness and extreme vigilance. Prompt recognition and appropriate action can mitigate the potential poor outcomes and improve patient prognosis.

Concomitant back and leg pain as predictors for trajectories of poor outcome after single level lumbar micro-decompression alone and with micro-discectomy: a study of 3,308 patients.

BACKGROUND: Lumbar decompression is the commonest spinal intervention. One in four patients have suboptimal outcome postoperatively, however no large studies identified clear poor outcome predictors. The aim of this study was to study low back pain (LBP) as a predictor of poor outcome following lumbar micro-decompression. METHODS: Prospectively collected spinal registry data was analysed for patients who underwent primary, single-level, decompression with or without discectomy at single spinal centre (2011-2017). Based on the response to the Likert global outcome question, we had two outcome groups (good & poor). Percentage of achievement of minimum clinically relevant change (MCRC) for Core Outcome Measures Index (COMI) score, LBP and leg pain (LP) was examined. A two-step approach was adopted. First, COMI score, LBP and LP visual analogue scales (VAS) trajectories were modelled using a discrete mixture model. Second, multinomial logistic regression was used to determine the association between variables and trajectories. RESULTS: We included 3,308 patients with mean follow up (1.4 y). MCRC was achieved in COMI score in 63% of cases, 42% in LBP and 62% in LP. A three-group trajectory model was identified: large-improvement (LI) (n=980), moderate-improvement (MI) (n=1,364) and no-improvement (NI) (n=966) with 99.5%, 84.5% and 31.5% of patients presenting good outcome, respectively. Higher pre-operative LBP and COMI score and smoking were strongly associated with MI and NI. In addition, higher LP, post-operative surgical complications, previous surgery at same level, conservative treatment >6 months and anxiety/depression were associated with NI. CONCLUSIONS: This is the first large-scale study reporting preoperative LBP severity, spinal stenosis and smoking as predictors for poor functional outcomes post lumbar decompression with or without discectomy. This is very useful while counselling patients for surgery to meet realistic expectations.

The safety, efficacy, and cost-effectiveness of intraoperative cell salvage in metastatic spine tumor surgery.

BACKGROUND CONTEXT: Metastatic spine tumor surgery (MSTS) is associated with substantial blood loss, therefore leading to high morbidity and mortality. Although intraoperative cell salvage with leukocyte depletion filter (IOCS-LDF) has been studied as an effective means of reducing blood loss in other surgical settings, including the spine, no study has yet analyzed the efficacy of reinfusion of salvaged blood in reducing the need for allogenic blood transfusion in patients who have had surgery for MSTS. PURPOSE: This study aimed to analyze the efficacy, safety, and cost-effectiveness of using IOCS-LDF in MSTS. STUDY DESIGN: This is a retrospective controlled study. PATIENT SAMPLE: A total of 176 patients undergoing MSTS were included in the study. METHODS: All patients undergoing MSTS at a single center between February 2010 and December 2014 were included in the study. The primary outcome measure was the use of autologous blood transfusion. Secondary outcome measures included hospital stay, survival time, complications, and procedural costs. The key predictor variable was whether IOCS-LDF was used during surgery. Logistic and linear regression analyses were conducted by controlling variables such as tumor type, number of diseased vertebrae, approach, number and site of stabilized segments, operation time, preoperative anemia, American Society of Anesthesiologists (ASA) grade, age, gender, and body mass index (BMI). No funding was obtained and there are no conflicts of interest to be declared. RESULTS: Data included 63 cases (IOCS-LDF) and 113 controls (non-IOCS-LDF). Intraoperative cell salvage with LDF utilization was substantively and significantly associated with a lower likelihood of allogenic blood transfusion (OR=0.407, p=.03). Intraoperative cell salvage with LDF was cost neutral (p=.88). Average hospital stay was 3.76 days shorter among IOCS-LDF patients (p=.03). Patient survival and complication rates were comparable in both groups. CONCLUSIONS: We have demonstrated that the use of IOCS-LDF in MSTS reduces the need for postoperative allogenic blood transfusion while maintaining satisfactory postoperative hemoglobin. We recommend routine use of IOCS-LDF in MSTS for its safety, efficacy, and potential cost benefit.

The effect of metal density in thoracic adolescent idiopathic scoliosis.

PURPOSE: Determine impact of metal density on curve correction and costs in thoracic adolescent idiopathic scoliosis (AIS). Ascertain if increased metal density is required for larger or stiffer curves. METHODS: Multicentre retrospective case series of patients with Lenke 1-2 AIS treated with single-stage posterior only surgery using a standardized surgical technique; constructs using >80 % screws with variable metal density. All cases had >2-year follow up. Outcomes measures included coronal and sagittal radiographic outcomes, metal density (number of instrumented pedicles vs total available), fusion length and cost. RESULTS: 106 cases included 94 female. 78 Lenke 1. Mean age 14 years (9-26). Mean main thoracic (MT) Cobb angle 63° corrected to 22° (66 %). No significant correlations were present between metal density and: (a) coronal curve correction rates of the MT (r = 0.13, p = 0.19); (b) lumbar curve frontal correction (r = -0.15, p = 0.12); (c) correction index in MT curve (r = -0.10, p = 0.32); and (d) correction index in lumbar curve (r = 0.11, p = 0.28). Metal density was not correlated with change in thoracic kyphosis (r = 0.22, p = 0.04) or lumbosacral lordosis (r = 0.27, p = 0.01). Longer fusions were associated with greater loss of thoracic kyphosis (r = -0.31, p = 0.003). Groups differing by preoperative curve size and stiffness had comparable corrections with similar metal density. The pedicle screw cost represented 21-29 % of overall cost of inpatient treatment depending on metal density. CONCLUSIONS: Metal density affects cost but not the coronal and sagittal correction of thoracic AIS. Neither larger nor stiffer curves necessitate high metal density.

Congenital C1 arch deficiency: Grand Round presentation.

INTRODUCTION: We present an uncommon and yet interesting congenital anomaly and discuss the difficulties with diagnosis and controversies in management. C1 arch deficiency is an important consideration in the differential diagnosis of neck pain in children. MATERIAL AND METHODS: A 12-year-old girl presented initially with a loud clicking emanating from the cervical spine during nappy changes in early childhood. Subsequent investigation by way of CT and MRI revealed her to have a deficient posterior arch of the C1 vertebra, and due to persistent and painful clicking she was placed into a cervical brace, which was worn for approximately 1 year. At age 12, her clicking had all but completely resolved but she continued to complain of minor neck pain. She is advised to avoid contact sports and her parents are instructed to observe any new worrying symptoms. CONCLUSION: No definitive guidelines exist for the management of this congenital anomaly. Indications for surgical intervention prior to any neurological disturbance are unclear, and restricting a child from partaking in healthy activity may not be necessary. We discuss the anomaly and identified management strategies as reported in the literature so far.