Entrapment of crural branches of the common peroneal nerve.

Failed back surgery syndrome (FBSS) occurs in 30% of operated patients and represents a heavy problem both regarding disability and costs in first world countries. Among FBSS we found the possibility of a double crush syndrome: a disco-radicular conflict and a peripheral nerve entrapment. The latter, disguised by root compression symptoms, becomes evident only after spinal surgery. Clinical features are the same as for the restless leg syndrome. We found peroneal nerve crural branches entrapped where they crossed the fascia to reach the subcutaneous layer. Venous stasis during immobility caused presentation of symptoms. Neurolysis was performed, all cases were successful. Most of the patients were found to have myofascial pain syndrome (MPS). MPS patients "feel" entrapments more frequently than others not because of their specific pain tolerance but because they are more prone to develop them.