Contralateral femoral nerve compression: An unrecognized complication after extreme lateral interbody fusion (XLIF).

Extreme lateral interbody fusion (XLIF) is a relatively new procedure for the treatment of degenerative disc disease avoiding the morbidity of anterior approaches. Ipsilateral L2-5 nerve root irritation and injury are well-described complications. We describe two patients with contralateral extremity symptoms, not reported so far. In the first patient the injury was caused by a displaced endplate fragment compressing the contralateral nerve root; in the second patient, the injury resulted from a far-lateral herniation after the XLIF procedure. Both patients experienced resolution of their symptoms after being reoperated. Overall, this complication was encountered in 2/32 levels treated during the study period. Overzealous endplate removal and breaking of the osteophytes in the opposite corner of the intervertebral disc, although desirable for maximal coronal deformity correction, may lead to irritation of the contralateral nerve roots. Attention is needed especially where the interbody cage is placed posteriorly or diagonally towards the neuralforamen.