Having only 11 pairs of ribs is more common than you might think. It's considered an anatomical variation, meaning it's a difference in structure that's present in a small percentage of otherwise healthy individuals.
The Prevalence of 11 Rib Pairs
Studies suggest that 5-8% of the population naturally have 11 pairs of ribs instead of the typical 12. Radiopaedia.org This is often an incidental finding, meaning it's discovered during imaging for other reasons and doesn't cause any symptoms. Radiopaedia.org The exact incidence isn't fully understood, and further research is needed to determine its prevalence completely. sciencedirect.com
Underlying Conditions
While having 11 ribs is frequently a normal variation, it can sometimes be associated with underlying genetic conditions. The most common association is with trisomy 21 (Down syndrome), where approximately one-third of individuals may have a missing twelfth rib. Radiopaedia.org Other less frequent associations include cleidocranial dysplasia and campomelic dysplasia. Radiopaedia.org
Clinical Significance
The presence of 11 ribs in itself may not cause any health problems. However, it's crucial to note that this finding can have implications for certain medical procedures, particularly those involving the spine. Accurate rib counts are essential for precise surgical planning and execution. pubmed.ncbi.nlm.nih.gov Misidentification of the rib count could lead to incorrect vertebral level identification during injections or other spinal procedures. anesth-pain-med.org
Important Note
If you've been diagnosed with having 11 pairs of ribs, it's vital to discuss this with your healthcare provider to assess the context of the finding and exclude any possible underlying conditions.
