Successful Criteria for Indirect Decompression With Lateral Lumbar Interbody Fusion.

Purpose: No consensus criteria have been established regarding ideal candidates for indirect decompression with lateral lumbar interbody fusion (LLIF), and contributing factors of indirect decompression failure were rarely reported. We aim to investigate the success rate of indirect decompression by LLIF with proposed selection criteria and identify risk factors associated with indirect decompression failure, defined as persistent pain requiring revision with direct decompression.

Methods: Data from 191 patients undergoing LLIF were retrospectively reviewed. All the following criteria must be fulfilled: 1) dynamic clinical symptoms (pain relief in supine position), 2) presence of reducible disc height (recovered disc height in supine position), 3) no profound weakness and 4) no static stenosis. The success rate of indirect decompression with LLIF and results after at least 1-year of follow-up were collected. Preoperative, procedure-related, and postoperative factors were assessed for their relationship with failure.

Results: Of 191 patients,13 patients (6.8%) required additional direct decompression due to persistent pain, giving a criteria success rate of 93.2%. Factors associated with indirect decompression failure included low bone mineral density (BMD) (T-score < 2.1), low reducible disc height (<13%), low postoperative disc height (<10 mm), high-grade cage subsidence, and use of plate fixation.

Conclusion: We proposed patient selection criteria for indirect decompression with LLIF which had a satisfactory success rate and identified factors associated with the need for additional direct decompression. Our proposed criteria may assist selection of patients likely to achieve good results following indirect decompression with LLIF, and optimize selection based on risk factors of failure.