Proximity of the common peroneal nerve to the tibial nerve entering the gastrocnemius muscle: the implications for calf reduction.

This article describes the precise anatomic relation and close proximity of the common peroneal nerve (PN) to the tibial nerve branch entering the gastrocnemius muscle (NLG) in the popliteal region. For the study, 22 legs from 13 Korean fresh cadavers (5 men and 8 women ranging in age from 50 to 80 years) were dissected. An x-axis was set as a transverse line crossing the lateral and medial epicondyle of the femur. A longitudinal y-axis accorded with a perpendicular midline between the medial malleoulus of the tibia and the lateral malleolus of the fibula. The PN diverged from the sciatic nerve above the interepicondylar line (-0.4 cm, +10.3 cm) and ran inferolaterally at 20.2 degrees +/- 2.4 degrees . The PN crossed the midpoint of the x-axis (+3.4 cm, 0 cm). The NLG diverged from the tibial nerve above the interepicondylar (transverse) line (0 cm, 2.3 cm) and ran inferiorly and laterally at 17.7 degrees +/- 4.3 degrees . The distance from the diverging point of the NLG from the tibial nerve to the nearest point of the PN was 2.5 +/- 0.5 cm. The distance from the point at which the PN crossed the x-axis to the nearest point of the NLG was 2.7 +/- 0.3 cm. In procedures that involve handling of the lateral gastrocnemius muscle itself or the nerves to the lateral gastrocnemius, surgeons should be aware of the close proximity of the PN to the NLG in the popliteal region.