[PhD Win case record] lateral sural cutaneous nerve entrapment |sharp pain knee, severe leg pain

The patient is a 50-year-old male from South Africa.

He presents with sharp knee pain for one day. He twisted his knee after falling off the bed, and since then, he has been unable to walk normally or straighten his leg. He also reports poor sleep due to the sharp pain.

Why do I suspect a single lateral sural cutaneous nerve entrapment?

1, The sharp pain is located on the lateral side of the right knee and radiates to the lateral aspect of the right lower leg.

2, There is a sensitive area on the upper lateral side of the right lower leg.

3, Both dorsiflexion and plantarflexion are normal.

4 If the entrapment is at the point where the lateral sural cutaneous nerve branches off from the common peroneal nerve, there would be involvement of the common peroneal nerve, which could lead to foot weakness. However, if the entrapment occurs below this point, where the lateral sural cutaneous nerve has already split off, only the common peroneal nerve would be affected, without signs of lateral sural cutaneous nerve damage. In this case, there would be not sensitivity in the upper lateral part of the lower leg.

Thanks