[Minimally invasive stand-alone fusion of the lumbosacral junction].

OBJECTIVE

Stable interbody fusion of the lumbosacral segment via an anterior retroperitoneal approach using an interbody spacer as an anterior stand-alone device which is fixed with four locking screws.

INDICATIONS: Degenerative disc disease without instability or deformity; adjacent segment degeneration; pseudarthrosis.

CONTRAINDICATIONS: Translational instabilities as in spondylolisthesis at the index segment; deformities; steep sacral slope. Challenging vascular situation with aortic bifurcation and/or venous confluence in front of L5/S1; osteoporosis. Relative: previous abdominal/gynecological surgery; infection/tumor/trauma.

SURGICAL TECHNIQUE: Access to the lumbosacral junction via a mini-open laparotomy using a retroperitoneal approach, insertion of a retractor system, preparation of the lumbosacral segment and complete discectomy and endplate preparation, distraction of the disc space, assessment of the adequate implant size, packing of the device and the disc space with bone graft substitute, insertion of the device in the intervertebral space, fixation of the implant by inserting two screws each into the cranial and caudal vertebral body, X‑ray control, withdrawal from the surgical site under constant assessment for possible lesions, wound closure.

POSTOPERATIVE MANAGEMENT: Immediate full load-bearing mobilization within 4-6 h postoperatively, external brace optional, resumption of sporting activities 3-6 months postoperatively.

RESULTS

From 2005-2012, of the original 77 patients who underwent surgery, 71 patients (26 men, 45 women; 92.2%) were followed up for an average of 35.1 months (range 12-85 months). The overall complication rate was 12.7%; the reoperation rate was 2.8%. At final follow-up, 77.5% of the patients were satisfied and 22.5% were not satisfied. The ODI and the VAS scores revealed significant improvements over the entire follow-up period. X‑ray analysis demonstrated a significant improvement of segmental lordosis. Solid bony fusion (determined by CT) was observed in 97.3%.