Deep learning algorithm for fully automated measurement of sagittal balance in adult spinal deformity.

AIM: Deep learning (DL) algorithms can be used for automated analysis of medical imaging. The aim of this study was to assess the accuracy of an innovative, fully automated DL algorithm for analysis of sagittal balance in adult spinal deformity (ASD). MATERIAL AND METHODS: Sagittal balance (sacral slope, pelvic tilt, pelvic incidence, lumbar lordosis and sagittal vertical axis) was evaluated in 141 preoperative and postoperative radiographs of patients with ASD. The DL, landmark-based measurements, were compared with the ground truth values from validated manual measurements. RESULTS: The DL algorithm showed an excellent consistency with the ground truth measurements. The intra-class correlation coefficient between the DL and ground truth measurements was 0.71-0.99 for preoperative and 0.72-0.96 for postoperative measurements. The DL detection rate was 91.5% and 84% for preoperative and postoperative images, respectively. CONCLUSION: This is the first study evaluating a complete automated DL algorithm for analysis of sagittal balance with high accuracy for all evaluated parameters. The excellent accuracy in the challenging pathology of ASD with long construct instrumentation demonstrates the eligibility and possibility for implementation in clinical routine.

Validation of the Subjective Spine Value: A new single item score for the assessment of spine-specific function.

BACKGROUND: Spinal function can be assessed through different patient reported outcome measures (PROMs). PURPOSE: The aim of the present study was to evaluate a novel single-item score for the assessment of spinal function: The Subjective Spine Value (SSpV). It was hypothesized that the SSpV correlates with the established scores Oswestry disability index (ODI) and Core Outcome Measures Index (COMI). METHODS: Between 08/2020 and 11/2021 151 consecutive patients were prospectively enrolled and completed a questionnaire with the ODI, COMI as well as the SSpV. Patients were divided into 4 groups depending on their specific pathology (Group 1: Degenerative pathologies, Group 2: Tumor, Group 3: Inflammatory / Infection, Group 4: Trauma). Pearson correlation coefficient was used to evaluate correlation between the SSpV and the ODI and COMI separately. Floor and ceiling effects were evaluated. RESULTS: Overall, the SSpV correlated significantly with both ODI (p = < 0.001; r = - 0.640) and COMI (p = < 0.001; r = - 0.640). This was also observed across all investigated groups (range - 0.420-0.736). No relevant floor or ceiling effects were noticed. CONCLUSIONS: The SSpV is a valid single-item score for the assessment of spinal function. The SSpV offers a useful tool to efficiently assess spinal function in a variety of spinal pathologies. LEVEL OF EVIDENCE: I, prospective cohort study.

Impact of Individual Spinopelvic Anatomy on the Localization and Severity of Symptomatic Isthmic Spondylolisthesis.

STUDY DESIGN: Retrospective analysis of prospectively collected data. OBJECTIVES: Isthmic spondylolisthesis (iSPL) occurs most commonly in L5/S1 and L4/5. This study investigates the association between spinopelvic anatomy and the pathogenesis of iSPL. METHODS: Spinopelvic parameters as well as severity of slip grade were measured in sagittal spine radiographs of symptomatic patients with iSPL in segments L4/5 and L5/S1. Means were calculated and differences between both groups were analyzed. A correlation between the analyzed parameters and degree of slippage was performed. RESULTS: We included 73 subjects in this study; 11 in L4/5 group and 62 in L5/S1 group. Pelvic anatomy significantly differed between L4/5 and L5/S1 iSPL (Pelvic Incidence (PI) 54.8° vs 66.3°, P value = .006; Pelvic Radius (PR) 124.4 mm vs 137.4 mm; P value = .005 and Sacral Table Angle (STA) 101.0° vs 92.2°, P value < .001). The relative degree of slippage was significantly higher in the L5/S1 group (L4/5 29.1% vs L5/S1 40.1%, P value .022). We also observed a significant correlation between pelvic anatomy and the severity of the slip in iSPL at the L5/S1 level. CONCLUSIONS: Pelvic parameters PI and STA play an important role concerning the level of occurrence and severity of iSPL. Spinopelvic anatomy determines the pathogenesis of iSPL.

Antibiotic-induced fever in orthopaedic patients-a diagnostic challenge.

INTRODUCTION: Antibiotic-induced fever is a probably underestimated complication, which may be misdiagnosed as new infection. In this study, characteristics, diagnostic approach, and outcome of antibiotic-induced fever in patients treated for musculoskeletal infections are described. METHODS: We retrospectively reviewed all patients with antibiotic-induced fever after surgery treated at our institution from 2014 to 2017. Antibiotic-induced fever was diagnosed, if the following criteria were fulfilled: (i) central (ear) body temperature > 38.0 °C; (ii) intravenous antibiotics for > three days; (iii) exclusion of infectious or other non-infectious causes of fever; and (iv) defervescence after discontinuation of antibiotics. RESULTS: We included 11 patients (median age 51 years) treated for infection after fracture fixation (n = 5), periprosthetic joint infections (n = 3), infection after spinal instrumentation (n = 1), and soft tissue infection (n = 2). The suspected antibiotics inducing fever were beta-lactam antibiotics (n = 9), vancomycin (n = 3), daptomycin (n = 2), clindamycin, and meropenem (n = 1 each). Additional clinical findings were reduced general condition, generalized exanthema, and rigors, whereas five patients were asymptomatic apart from a fever. Leukopenia was observed in nine patients and increase of C-reactive protein value in ten patients. Fever occurred after a median of 20 days of antibiotic treatment and resolved after a median of one day after discontinuation of the suspected antibiotic. CONCLUSIONS: Antibiotics should be considered as the possible cause of fever in orthopaedic patients receiving antimicrobial treament whenever clinical signs of new or persisting infection are lacking. Important hints suggestive for antibiotic-induced fever are good general condition despite high temperature and progressive leukopenia. Discontinuation or change to another substance leads to prompt defervescence, preventing unnecessary diagnostic procedures and antibiotic treatment.

Proteomic profiling in Lipocalin 2 deficient mice under normal and inflammatory conditions.

Lipocalin 2 (LCN2) belongs to the superfamily of lipocalins which represent a group of small secreted proteins classified as extracellular transport proteins expressed in many tissues. LCN2 is strongly increased in experimental models of acute and chronic liver injuries. To investigate the function of LCN2 in normal liver homeostasis and under conditions of inflammatory liver injury, we comparatively analyzed hepatic extracts taken from Lcn2-deficient and wild type mice under basal conditions and after stimulation with lipopolysaccharides. Liver was chemically and mechanically lysed and extracts were subjected to 2-D-DIGE after minimal labeling (G200 and G300 dyes) using an appropriate internal standard (G100). Afterwards MALDI TOF MS and MS/MS were used to identify differentially expressed proteins. Proteins that were identified to be differentially expressed include for example the chloride intracellular channel protein 4 (CLIC4), aminoacylase 1 and transketolase. The altered expression of respective genes was confirmed by Western blot analysis and further validated by quantitative real time PCR. Altogether, the complex expression alterations in mice lacking LCN2 under normal conditions and after exposure to inflammatory stimuli reveal that LCN2 has essential function in liver homeostasis and in the onset of inflammatory responses in which LCN2 expression dramatically increases.