Purpose ¹⁸F-Fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET/CT) is frequently used to diagnose fracture-related infections (FRIs), but its diagnostic performance in this field is still unknown. The aims of this study were: (1) to assess the diagnostic performance of qualitative assessment of ¹⁸F-FDG PET/CT scans in diagnosing FRI, (2) to establish the diagnostic performance of standardized uptake values (SUVs) extracted from ¹⁸F-FDG PET/CT scans and to determine their associated optimal cut-off values, and (3) to identify variables that predict a false-positive (FP) or false-negative (FN) ¹⁸F-FDG PET/CT result. Methods This retrospective cohort study included all patients with suspected FRI undergoing ¹⁸F-FDG PET/CT between 2011 and 2017 in two level-1 trauma centres. Two nuclear medicine physicians independently reassessed all ¹⁸F-FDG PET/CT scans. The reference standard consisted of the result of at least two deep, representative microbiological cultures or the presence/absence of clinical confirmatory signs of FRI (AO/EBJIS consensus definition) during a follow-up of at least 6 months. Diagnostic performance in terms of sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) was calculated. Additionally, SUVs were measured on ¹⁸F-FDG PET/CT scans. Volumes of interest were drawn around the suspected and corresponding contralateral areas to obtain absolute values and ratios between suspected and contralateral areas. A multivariable logistic regression analysis was also performed to identify the most important predictor(s) of FP or FN ¹⁸F-FDG PET/CT results. Results The study included 156 ¹⁸F-FDG PET/CT scans in 135 patients. Qualitative assessment of ¹⁸F-FDG PET/CT scans showed a sensitivity of 0.89, specificity of 0.80, PPV of 0.74, NPV of 0.91 and diagnostic accuracy of 0.83. SUVs on their own resulted in lower diagnostic performance, but combining them with qualitative assessments yielded an AUC of 0.89 compared to an AUC of 0.84 when considering only the qualitative assessment results (p = 0.007). ¹⁸F-FDG PET/CT performed <1 month after surgery was found to be the independent variable with the highest predictive value for a false test result, with an absolute risk of 46% (95% CI 27–66%), compared with 7% (95% CI 4–12%) in patients with ¹⁸F-FDG PET/CT performed 1–6 months after surgery. Conclusion Qualitative assessment of ¹⁸F-FDG PET/CT scans had a diagnostic accuracy of 0.83 and an excellent NPV of 0.91 in diagnosing FRI. Adding SUV measurements to qualitative assessment provided additional accuracy in comparison to qualitative assessment alone. An interval between surgery and ¹⁸F-FDG PET/CT of <1 month was associated with a sharp increase in false test results.

In the anatomy of a normal spine, due to the curvatures in various regions, the C7 plumb line (C7PL) passes through the sacrum so that the head is centered over the pelvic-ball and socket hip and ankle joints. A failure to recognize malalignment in the sagittal plane can affect the patient's activity as well as social interaction due to deficient forward gaze. The sagittal balance configuration leads to the body undertaking the least muscular activities as possible necessary to maintain spinal balance. Global sagittal imbalance is energy consuming and often results in painful compensatory mechanisms that in turn negatively influence the patient's quality of life, self-image, and social interaction due to inability to maintain a horizontal gaze. Deformity, scoliosis, kyphosis, trauma, and/or surgery are some ways that this optimal configuration can be disturbed, thus requiring higher muscular activity to maintain posture and balance. Several parameters such as the thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SS), and hip and leg positions influence the sagittal balance and thus the optimal configuration of spinal alignment. This review examines the clinical and biomechanical aspects of spinal imbalance, and the biomechanics of spinal balance as dictated by deformities—ankylosing spondylitis (AS), scoliosis and kyphosis; surgical corrections—pedicle subtraction osteotomies (PSO), long segment stabilizations, and consequent postural complications like proximal and distal junctional kyphosis. The study of the biomechanics involved in spinal imbalance is relatively new and thus the literature is rather sparse. This review suggests several potential research topics in the area of spinal biomechanics.

Systematic review and meta-analysis. To determine the efficacy of intrawound treatments in reducing deep surgical site infections (SSIs) in instrumented spinal surgery. The electronic databases MEDLINE, EMBASE, and Cochrane were systematically searched for intrawound treatments for the prevention of SSIs in clean instrumented spine surgery. Both randomized controlled trials and comparative cohort studies were included. The results of included studies were pooled for meta-analysis. After full text- and reference screening, 20 articles were included. There were 2 randomized controlled trials and 18 observational studies. Sixteen studies investigated the use of intrawound antibiotics, and 4 studies investigated the use of intrawound antiseptics. The relative risk of deep SSI for any treatment was 0.26 (95% confidence interval [CI] 0.16-0.44, P < .0001), a significant reduction compared with controls receiving no treatment. For patients treated with local antibiotics the relative risk was 0.29 (95% CI 0.17-0.51, P < .0001), and patients treated with local antiseptics had a relative risk of 0.14 (95% CI 0.05-0.44, P = .0006). Both the use of antibiotic and antiseptic intrawound prophylactics was associated with a significant 3 to 7 times reduction of deep SSIs in instrumented spine surgery. No adverse events were reported in the included studies.

Current surgical treatment options for Early Onset Scoliosis (EOS), with distraction-based implants or growth-guidance systems, show limited growth and high complication rates during follow-up. We developed a novel implant concept, which uses compressed helical springs positioned around the rods of a growth-guidance construct. This Spring Distraction System (SDS) provides continuous corrective force to stimulate spinal growth, can be easily contoured, and can be used with all standard spinal instrumentation systems. To assess the curve correction and maintenance, spinal growth, complication rate, and Health-Related Quality of Life (HRQoL) following SDS treatment. Prospective cohort study. All skeletally immature EOS patients with an indication for growth-friendly surgery and without bone- or soft tissue weakness were eligible to receive SDS. For this study, all included patients with at least 2-year follow-up were analyzed. Coronal Cobb angle, sagittal parameters, T1-T12, T1-S1 and instrumented (i.e. bridged segment) spinal height and freehand length, complications and re-operations, and the 24-Item Early Onset Scoliosis Questionnaires (EOSQ-24) score. All primary- and revision patients (conversion from failed other systems) with SDS and ≥2 years follow-up were included. Radiographic parameters were compared pre-operatively, post-operatively and at latest follow-up. Spinal length increase was expressed as mm/year. Twenty-four skeletally immature EOS patients (18 primary and 6 revision cases) were included. There were 5 idiopathic, 7 congenital, 3 syndromic and 9 neuromuscular EOS patients. Mean age at implantation was 9.1 years (primary: 8.4; conversion: 11.2). Major curve improved from 60.3° to 35.3°, and was maintained at 40.6° at latest follow-up. Mean spring length increase during follow-up was 10.4mm/year. T1-S1 height increased 9.9mm/year and the instrumented segment height showed a mean increase of 0.7mm/segment/year. EOSQ-24 scores dropped after surgery from 75.6 to 67.4 but recovered to 75.0 at latest follow-up. In total, 17 re-operations were performed. Ten re-operations were performed to treat 9 implant-related complications. In addition, 7 patients showed spinal growth that exceeded expected growth velocity; their springs were re-tensioned during a small re-operation. The 2-year follow-up results from this prospective cohort study indicate that the concept of spring distraction may be feasible as an alternative to current growing spine solutions. Curve correction and growth could be maintained satisfactory without the need for repetitive lengthening procedures. However, as in all growth-friendly implants, complications and re-operations could not be prevented, which emphasizes the need for further improvement.

Purpose: Current treatment of progressive early onset scoliosis involves growth-friendly instrumentation if conservative treatment fails. These implants guide growth by passive sliding or repeated lengthenings. None of these techniques provide dynamic correction after implantation. We developed the spring distraction system (SDS), by using one or multiple compressed springs positioned around a standard sliding rod, to provide active continuous distraction of the spine to stimulate growth and further correction. The purpose of this study was to determine feasibility and proof of concept of the SDS. Methods: We developed a versatile, dynamic spring distraction system for patients who would benefit from active continuous distraction. This prospective case series evaluates four patients with exceptional and progressive congenital spine deformities. Results: Four patients had a mean age of 6.8 years at surgery with a mean follow-up of 36 months (range 25–45). The mean progressive thoracic lordosis, which was the reason for initiating surgical treatment in two patients, changed from 32° lordosis preoperatively to 1° kyphosis post-operatively. During follow-up, this further improved to 32° thoracic kyphosis. In the two other patients, with cervicothorcacic scoliosis, the main coronal curve improved from 79° pre-operatively to 56° post-operatively and further improved to 42°. The mean T1-S1 spine growth during follow-up for all patients was 1.3 cm/year. There was one reoperation because of skin problems and no device-failures. Conclusion: These early results show the feasibility and the proof of concept of spring-based distraction as a dynamic growth-enhancing system with the potential of further correction of the deformity after implantation.