When Indirect Decompression Fails

A Review of 220 Consecutive Direct Lateral Interbody Fusions and Unplanned Secondary Decompression

Clinton D. Morgan, MD; Corey T. Walker, MD; Jakub Godzik, MD; Ifije E. Ohiorhenuan, MD, PhD; Joshua S. Catapano, MD; Courtney Hemphill, MS; Juan S. Uribe, MD


Spine. 2021;46(16):1081-1086. 

In This Article

Abstract and Introduction


Study Design: A consecutive series of patients who underwent minimally invasive spinal surgery by a single surgeon at a high-volume academic medical center were studied.

Objective: The objective of this study was to identify the prevalence, radiographic features, and clinical characteristics of patients who require unplanned secondary decompressive laminectomy or foraminotomy after lateral lumbar interbody fusion (LLIF).

Summary of Background Data: LLIF indirectly decompresses the spinal canal, lateral recess, and neural foramen when properly performed. However, indirect decompression relies on endplate integrity, reasonable bone quality, and sufficient contralateral release so that ligament distraction can occur. Some patients have insufficient decompression, resulting in persistent axial low back pain or radiculopathy.

Methods: Patients undergoing LLIF for radiculopathy or refractory low back pain were enrolled in a prospective registry. Preoperative and postoperative imaging, clinical presentation, and operative reports were reviewed from this registry.

Results: During registry collection, 122 patients were enrolled (220 lumbar levels treated), with nearly even representation between men (64/122, 52.5%) and women (58/122, 47.5%). Overall, right-sided lumbar spinal approaches (74/122, 60.7%) were more common. Ultimately, 4.1% (five of 122) of patients required unplanned direct decompressive laminectomy or foraminotomy because of refractory radiculopathy and persistent radiographic evidence of compression at the index LLIF level. All patients for whom indirect decompression failed were men who underwent stand-alone LLIF and had radiculopathy contralateral to the side of the LLIF approach. Most patients (59.8%, 73/122) had evidence of graft subsidence (grade 0 or 1) or osteoporosis.

Conclusion: We report a 4.1% rate of return to the operating room for failed indirect decompression after LLIF for refractory radiculopathy. Graft subsidence and osteoporosis were common in these patients. All five patients who required secondary decompressive laminectomy or foraminotomy underwent stand-alone primary LLIF, and the persistent radiculopathy was consistently contralateral to the initial side of the LLIF approach.

Level of Evidence: 4


Transpsoas lateral lumbar interbody fusion (LLIF), when performed on properly selected patients, offers a minimally invasive approach for clinically significant indirect decompression of the central canal, lateral recess, and neural foramen. Large-footprint interbody cages placed from an anterolateral trajectory can restore disk height, distract the posterior longitudinal ligament, unbuckle the ligamentum flavum, and enlarge the epidural space.[1]

For surgeons to achieve clinically meaningful indirect decompression, a careful preoperative examination includes an assessment of disk height, vacuum disk phenomenon, and degenerative autofusion in the facet joint. Meticulous intraoperative attention is given to disk space preparation to promote arthrodesis, protection of the cartilaginous endplate to prevent postoperative subsidence, and coronal concavity and osteophyte distribution because these factors can markedly affect disk space access and distraction. Even in ideally selected surgical candidates for LLIF, if the surgeon fails to consider these factors, the likelihood of successful indirect decompression plummets. Failed indirect decompression causes the patient to experience persistent postoperative low back pain from ongoing canal stenosis or radiculopathy because of inadequate lateral recess or neural foramina decompression. It remains unclear which patients experience clinically significant failed indirect decompression. It is essential to identify those patients with postoperative, referable symptoms sufficient to require unplanned direct decompression at the index LLIF level via laminectomy or foraminotomy.[2–6]