Earthquake generated proximal tibial nerve compression treated by surgery

Abstract

Purpose: This article reports on nine cases of proximal tibial nerve compression by the soleal tendinous arch caused by unsuitable treatment of acute compartment syndrome (ACS). Also, we report the clinical results of neurolysis and analyse the cause of this special type of neurological compression.

Methods: There were nine extremities in nine patients included in the study. All patients were among the victims of the Wenchuan earthquake in 2008. All patients had a previous lower extremity ACS. Pain level, numbness in the sole, muscle strength of the flexor hallucis longus and Tinel's sign were evaluated pre- and post-operatively. Each proximal tibial nerve compression was subjected to neurolysis with division of the soleal tendinous arch.

Results: At a mean follow-up of 22 months, eight patients (87 %) with weakness of the flexor hallucis longus showed improvement in flexor strength and seven patients (78 %) exhibited improved sensory function in the sole. All patients experienced pain relief. Subjective pain was reduced from an average score of 2.7 to 0.7 based on a visual analogue scale. Physical examination for Tinel's sign revealed all patients experienced relief of radiating pain, but two patients still retained a positive Tinel's sign (mild) over the soleal tendinous arch. In summary, four patients were highly satisfied, four were satisfied and one was neither satisfied nor dissatisfied with functional recovery after neurolysis.

Conclusions: Unsuitable treatment of lower extremity ACS can lead to tibial nerve compression beneath the soleal tendinous arch. Neurolysis may improve pain and sensory and motor function.

Fig. 1

The tibial nerve travels from the popliteal fossa to the deep posterior compartment by passing over the popliteus and beneath the tendinous arch of the soleus muscle

Fig. 2

Four patients’ ultrasound results showed mild tibial nerve thickening and the other five had negative results. MRI of all patients showed no specific compression on the very site of the soleal tendinous arch to the proximal tibial nerves

Fig. 3

The tibial nerve was compressed beneath the soleal tendinous arch (arrows)

Fig. 4

An image from a different patient shows visual narrowing (arrows) in the tibial nerve itself as it travelled beneath the soleal tendinous arch