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.

115 An Audit on Dexamethasone Prescribing Practice on Surgically Managed Metastatic Spinal Cord Compression Patients in the Manchester Centre for Clinical Neurosciences: Lessons Learned in Closing the Loop

Metastatic Spinal Cord Compression is a surgical emergency owing to its propensity to cause significant morbidity and mortality. Dexamethasone is prescribed to reduce oedema and promote vascular membrane stabilization. The is done so until a more definitive management has been performed.

This is a retrospective study evaluating the steroid-prescribing practice for MSCC patients in 2018 at a tertiary spinal unit in Greater Manchester. Thirty-three patients who underwent stabilisation were evaluated in terms of both steroid prescribing and weaning practices. Standards used against for both were the NICE guidelines and the Edinburgh/Christie’s guidelines.

Of the 33 patients evaluated, only 1 patient received the correct loading dose of 16mg, whilst 27 went straight to being given 8mg BD. 5 did not receive dexamethasone at all. In terms of discontinuation/weaning, 26 were weaned accordingly and 2 were not weaned to continue as adjuvant treatment.

Dexamethasone prescribing practises has since improved over the past two years. 93% of the patients have been correctly weaned as compared to 38% in the past. In terms of prescription, much needs to be done as almost all the patients evaluated did not get the correct loading dose despite receiving the appropriate maintenance.

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.

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.