68 - Anomalous Bifurcation and Coursing of the Sciatic Nerve Found During an Incidental Cadaveric Dissection of the Deep Gluteal Muscular Region

Poster Board Number: 68
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Co-authors:

Ferdinand Gomez, MS - Assistant Professor, Medical Education, Florida International University Herbert Wertheim College of Medicine

Abstract Body : Introduction:
Originating from the L4 to S3 ventral nerve roots of the lumbosacral trunk (eventually joining the sacral plexus), the expansive sciatic nerve derives from two main constituents: the tibial and common fibular/peroneal divisions. In most cases, this large nerve exits the pelvis through the greater sciatic foramen inferior to the piriformis muscle and descends between the greater trochanter of the femur and ischial tuberosity of the pelvis towards the popliteal fossa. At the level of the superolateral border of the popliteal fossa (in most cases), the sciatic nerve bifurcates into its terminal tibial and common fibular nerves.


Objective:
To describe the anomalous (bilateral) bifurcation of the sciatic nerve and its coursing found during an incidental cadaveric dissection of the deep gluteal muscular region.


Results:
In this case, the common fibular division emerged superior to the piriformis muscle (bilaterally), culminating in a proximal bifurcation (tibial and common fibular divisions) with a significant wide separation. The divisions reunited 5cm distally, subsequently branching normally at the popliteal fossa. In essence, there is the potential for symptoms matching piriformis syndrome or nerve lesions from intramuscular injections.



Conclusion:
Aberrant sciatic nerve anatomy could result in an increased risk of nerve compression/traction injuries. Cadaver dissection enables the discovery of clinically relevant variations as depicted in this rare case.



Significance and Implications:
Sciatic anomalies may potentially increase the risk of procedural injuries. Recognizing deviations such as bifid coursings or piriformis piercing, could guide gluteal/thigh surgical procedures and diagnosis of atypical neuropathy. Cadaveric findings reinforce the use of dissection as a vital tool in discovering anatomical variations.