Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral chest radiographs demonstrate a normal cardiomediastinal silhouette and well - aerated lungs without focal consolidation , pleural effusion , or pneumothorax . A left posterior ninth rib displaced fracture is noted . No other fracture is identified .
    OUTPUT:
    
Known displaced left posterior ninth rib fracture , without evidence of pneumothorax . No pleural effusion or focal consolidation .