Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There are numerous minimally displaced posterior left - sided rib fractures of at least the ___-___ robs . No significant pneumothorax is seen . Lungs are clear of focal consolidation or pleural effusions . The cardiac and mediastinal silhouette is normal .
    OUTPUT:
    
Numerous left posterior rib fractures . No pneumothorax , though assessment is limited by supine positioning .