Abstract
Introduction
Lateral lumbar interbody fusion (LLIF) by a transpsoas approach can avoid complications seen in other techniques. Lateral cages offer a larger cage and may increase stability by spanning the ring apophysis. Patients with multiple comorbidities, including smoking, diabetes, and obesity, have been shown to have decreased fusion rates. This study used computerized tomography (CT) scans to assess interbody fusion utilizing the LLIF technique in patients at high risk for nonunion and pseudoarthrosis.
Methods
We performed a retrospective review of patients who underwent LLIF between January 2008 and December 2013. A total of 64 patients with 151 levels underwent nonstaged or staged LLIF with posterior correction and augmentation. Per protocol, patients received CT scans at their 1-year follow-up. Of the 64 patients, 32 patients with 86 levels met inclusion criteria. Two board-certified musculoskeletal radiologists and the senior surgeon (J. Z.) assessed fusion.
Results
We performed six revision surgeries (18.75%). Other comorbidities included osteopenia/osteoporosis (46.8%), diabetes (25%), obesity (25%), and active smoking (25%), among others. Postoperative complications occurred in 15 patients (46.8%). Anterior thigh pain and weakness occurred in five patients (15.6%), all of which resolved by 6 months. There were five cases of delirium/postoperative confusion (15.6%). There were three cases of proximal junctional kyphosis, each requiring revision and cranial extension. Two cases of abdominal atonia occurred, one of which resolved at 1 year and the other still symptomatic at 1 year and 1 month. There were no cases of infection, ileus, UTI, catastrophic subsidence, DVT or PE. By CT scan assessment, each radiologist found solid fusion, as demonstrated by strong bridging trabeculae, was achieved in 84 out of 86 levels (97.6%). This was in agreement with the senior surgeon (J. Z.).
Conclusion
Several studies have evaluated LLIF fusion and reported fusion rates between 88 and 96%. Our results demonstrate high fusion rates (97.6%) using this technique, despite multiple comorbidities. Since stability plays a vital role in successful fusion, spanning the ring apophysis with a larger cage, along with pedicle screw supplementation, appear to be key factors.