ABSTRACT
Supernumerary ribs are a well-documented congenital anomaly that can occur at any point of the vertebral column, most commonly in the cervical or lumbar region. However, accessory ribs found in the sacrococcygeal region are exceptionally rare and may be difficult to distinguish from other bony manifestations of the pelvic girdle. During cadaveric dissection, a pair of sacral "ribs" were found projecting from the left posterolateral sacral region. The bony projections shared a broad base from the posterior sacrum. The projections followed an anteroinferior trajectory, mimicking the thoracic rib structure. Computed tomography (CT) revealed further bony anomalies, including bilateral ossifications embedded in the sacrotuberous ligament, and a blunt bony protrusion extending toward the ischial spine. Most documented supernumerary ribs in the lumbar and sacrococcygeal regions are asymptomatic and are incidental findings in radiographic studies during the exploration of other medical complaints. Correlated symptoms mentioned in the literature include pelvic pain and decreased hip range of motion, with potential obstetric complications. Owing to their asymptomatic nature, sacral ribs may be underreported. The primary aim of this report is to provide a detailed description of these sacral "ribs" in the unique setting of a cadaveric dissection supplemented with medical imaging to enhance visualization.
ABSTRACT
OBJECTIVES: Prompt antibiotic treatment of early stage Lyme borreliosis (LB) prevents progression to severe multisystem disease. There is a clinical need to improve the diagnostic specificity of early stage Lyme assays in the period prior to the mounting of a robust serology response. Using a novel analyte harvesting nanotechnology, Nanotrap particles, we evaluated urinary Borrelia Outer surface protein A (OspA) C-terminus peptide in early stage LB before and after treatment, and in patients suspected of late stage disseminated LB. METHOD: We employed Nanotrap particles to concentrate urinary OspA and used a highly specific anti-OspA monoclonal antibody (mAb) as a detector of the C-terminus peptides. We mapped the mAb epitope to a narrow specific OspA C-terminal domain OspA236-239 conserved across infectious Borrelia species but with no homology to human proteins and no cross-reactivity with relevant viral and non-Borrelia bacterial proteins. 268 urine samples from patients being evaluated for all categories of LB were collected in a LB endemic area. The urinary OspA assay, blinded to outcome, utilized Nanotrap particle pre-processing, western blotting to evaluate the OspA molecular size, and OspA peptide competition for confirmation. RESULTS: OspA test characteristics: sensitivity 1.7 pg/mL (lowest limit of detection), % coefficient of variation (CV) = 8 %, dynamic range 1.7-30 pg/mL. Pre-treatment, 24/24 newly diagnosed patients with an erythema migrans (EM) rash were positive for urinary OspA while false positives for asymptomatic patients were 0/117 (Chi squared p < 10(-6)). For 10 patients who exhibited persistence of the EM rash during the course of antibiotic therapy, 10/10 were positive for urinary OspA. Urinary OspA of 8/8 patients switched from detectable to undetectable following symptom resolution post-treatment. Specificity of the urinary OspA test for the clinical symptoms was 40/40. Specificity of the urinary OspA antigen test for later serology outcome was 87.5 % (21 urinary OspA positive/24 serology positive, Chi squared p = 4.072e(-15)). 41 of 100 patients under surveillance for persistent LB in an endemic area were positive for urinary OspA protein. CONCLUSIONS: OspA urinary shedding was strongly linked to concurrent active symptoms (e.g. EM rash and arthritis), while resolution of these symptoms after therapy correlated with urinary conversion to OspA negative.
