Abstract
Background Extraforaminal lumbar interbody fusion (ELIF) surgery is a muscle-sparing approach
that allows the treatment of various degenerative spinal diseases. It is technical
challenging to perform the ELIF approach at the L5–S1 level because the sacral ala
obstructs the view of the intervertebral disk space.
Methods We reported earlier on the ELIF technique in which the intervertebral disk is targeted
at an angle of 45 degrees relative to the midline. In this article we describe the
technical process we developed to overcome the anatomic relation between the sacral
ala and the intervertebral disk space L5–S1 that hinders the ELIF approach at this
level. We then report in a retrospective analysis on the short-term clinical and radiologic
outcome of 100 consecutive patients with degenerative L5–S1 pathologies who underwent
ELIF surgery.
Results The L5–S1 ELIF approach could be realized in all patients. The short-term clinical
outcome was evaluated 5 months after surgery: 92% of the patients were satisfied with
their postoperative result; 8% had a poor result. Overall, 17% of the patients presented
light radicular or low back pain not influencing their daily activity, and 82% of
the patients working before surgery returned to work 3 to 7 months after surgery.
The radiologic outcome was documented by computed tomography at 5 months after surgery
and showed fusion in 99% of the patients. Lumbar magnetic resonance imaging performed
in 5 patients at 6 months after surgery revealed the integrity of the paraspinal muscles.
Conclusions ELIF surgery at the L5–S1 level is technically feasible for various degenerative
spinal diseases. Analysis of the clinical and radiologic data in a consecutive retrospective
cohort of patients who underwent this surgical procedure showed a good short-term
clinical outcome and fusion rate.
Keywords
lumbar interbody fusion - extraforaminal approach - ELIF - L5–S1 level - paraspinal
muscles
