IJCRR

IJCRR - 7(10), May, 2015

Pages: 20-24

CADAVERIC STUDY OF THE EXIT OF SCIATIC NERVE

Author: Shaheen Rizvi, Sharadkumar Pralhad Sawant

Category: General Sciences

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Abstract:

Aims: To study the exit of sciatic nerve in 100 cadavers.
Materials and Methods: In the department of Anatomy of K.J.Somaiya Medical College, Sion, Mumbai, India, the study on exit of sciatic nerve was performed on 100 (200 specimens of Inferior Extremities) embalmed donated cadavers (80 males and 20 females). The specimens were classified into six groups.
Observations: In Type I, 106 (103 males and 3 female) of the 200 (53%) specimens, the exit of the sciatic nerve below piriformis muscle. In Type II, 44 (all males) out of 200 (22%) specimens, the exit of common peroneal nerve through piriformis muscle and
the tibial nerve below piriformis muscle. In Type III, 24 (22 males and 2 female) out of 200 (12%) specimens, the exit of common peroneal nerve above piriformis muscle and the tibial nerve below piriformis muscle. In Type IV, 16 (all males) out of 200 (8%) specimens, the exit of sciatic nerve through piriformis muscle. In Type V, 6 (4 males and 2 females) out of 200 (3%) specimens, the exit of tibial nerve above piriformis muscle and common peroneal nerve through piriformis muscle. In Type VI, 4 (all males) out of 200 (2%) specimens, the exit of sciatic nerve above piriformis muscle.
Conclusion: Sciatic nerve division into the tibial and common peroneal components at a higher level can result in the involvement of only one out of the two divisions in sciatic neuropathy. It can also result in a failure of the sciatic nerve block while performing popliteal block anaesthesia. These anatomical variations may contribute to clinical conditions such as piriformis  syndrome, sciatica and coccygodynia.

Keywords: Sciatic nerve, Gluteal region, Piriformis, Sciatic nerve block, Piriformis syndrome, Sciatica

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