gms | German Medical Science

Objective: Pathologies such as tumor disease, spondylodiscitis or burst fractures of the fifth lumbar vertebra require anterior column reconstruction as a single- or two- stage procedure. Apart from three case series, only a few case reports dealing with this topic have been published.

Method: All patients, who underwent a L5 corpectomy at our department between January 1^st 2010 and April 30^th 2015 were included. All patients underwent a baseline physical and neurological examination on admission. The diagnostic routine included MRI and CT scans prior to and after surgery. The local lordosis angle (L4(L3)-S1) was measured.

Results: 14 consecutive patients, who underwent an L5 corpectomy were included. 12 were treated with a L5 corpectomy, in 2 cases a L4 and L5 corpectomy was performed. The mean age was 66 years (range 24-84 years). The most common pathology was infection (N=7), 3 patients had neoplastic disease, 2 a pseudoarthrosis and 2 patients presented with fractures of the fifth lumbar vertebra. All patients underwent a posterior pedicle instrumentation and fusion. The L5 corpectomy was conducted through a left sided retroperitoneal approach, a distractable titanium cage was inserted. Two intraoperative complications (14%) were observed, one being a minor iliac vein injury that had to be repaired with fibrin glue. The other was severe arterial hypotension due to septic multi organ failure and the surgery had to be stopped. The median local lordotic angle (L4(L3) to S1) after posterior fixation prior to L5 corpectomy was 32.8° (range 17.5-48.9°), post corpectomy 35.7° (range 21.1-55.4°). We observed 3 cage dislocations (21%) postoperatively. One was after initial mobilization due to fracture of the L4 endplate in an osteoporotic patient. The 2 other implant failures occurred in spondylodiscitis patients with a L4(L3)-S1 lordosis of over 50°, whereas the median value was only 30.95° (range 21.1-46.2°) in the non-failed group. Other complications included one intestinal injury treated with side-to-side anastomosis, 1 postoperative pulmonary artery embolism and 2 wound infections in total, making three anterior revisions of the dislodged cages necessary. Additional anterior plating was used in 2 of the revision surgeries to secure the cage.

Conclusions: The radiological and clinical outcome seems to be better in patients with a small lordotic angle between L4(L3) and S1, since a high angle of >50° seems to facilitate cage dislocation. Anterior plating can be used to prevent such implant failure.