[Submuscular approach to the lumbar spine and extraforaminal cage implantation]

The posterior median approach to the lumbar spine may cause significant injury to the erector spinae muscles (ESM) which is minimized using the paralateral approach suggested by Ray. We have adopted this approach and have extended it into the disc space to allow cage implantation from outside the foramen (EPLIF - extraforaminal posterior lumbar interbody fusion). The initial exposure of the posterior vertebral elements between the ESM and the deep lumbar fascia is sufficient to attain the entry points of pedicle screws. The intervertebral foramen and posterior annulus fibrosus are then exposed after which distant lateral disc herniations may be removed, the foramen/lateral recess may be decompressed or an EPLIF performed following clearing and vertical distraction of the disc space. This is followed by ipsilateral transpedicular fixation (TpF), contralateral fixation (second approach) by TpF or translaminar screws. Indications are given for foraminal and extraforaminal disc herniation, stenosis of the foramen and/or of the lateral recess, posterolateral fusion, TpF and EPLIF. The submuscular approach and EPLIF have proven to be valuable alternatives to standard techniques.