Indirect decompression (ID) for the treatment of lumbar spondylolisthesis does not provide superior long-term clinical outcomes compared to direct decompression (DD), new research has suggested. The study—the results of which were presented by Lydia Joy McKeithan (UC Davis Department of Orthopaedic Surgery, Sacramento, USA) at the 2022 International Meeting on Advanced Spine Techniques (IMAST; 6–9 April; Miami, USA)—found that DD and ID strategies to treat lumbar spondylolisthesis were similar in regards to disability, quality of life, and patient satisfaction outcomes.
However, the study’s ID cohort demonstrated a statistically significant lower level of improvement in back and leg pain and a higher reoperation rate at three months. Despite this, these findings were not maintained out to 12 months.
The study compared three- and 12-month outcomes for patients with lumbar spondylolisthesis treated with DD versus ID and interbody fusion. Patient-reported outcomes were retrospectively obtained from the US Quality Outcomes Database (QOD), a longitudinal, multicentre, prospective spine outcomes registry.
Patients were separated into two treatment groups—DD (posterior lumbar laminectomy with transforaminal lumbar interbody fusion [TLIF]) or ID (anterior lumbar interbody fusion [ALIF], lateral lumbar interbody fusion [LLIF], oblique lumbar interbody fusion [OLIF] and posterior instrumentation/fusion without laminectomy).
Propensity scores for each treatment were estimated using logistic regression dependent on baseline covariates potentially associated with outcomes. The propensity scores were used to exclude non-similar patients. Multivariable regression analysis was performed with the treatment and covariate as independent variables and outcomes as dependent variables.
A total of 4,163 patients were included in the DD group and 86 in the ID group. The study found, when compared to the DD group at three months, the ID group had significantly lower odds of having a longer hospital stay, as well as lower odds of achieving 30% improvement in back pain (odds ratio [OR] 0.47; 95% confidence interval [CI], 0.287–0.769; p=0.003) and leg pain (OR 0.572; 95% CI, 0.334–0.982; p=0.043).
However, these trends were not statistically significant at 12 months for both back pain (p=0.346) and leg pain (p=0.166). The DD and ID cohorts did not significantly differ with respect to three- or 12-month postoperative improvement in Oswestry Disability Index (ODI), EQ-5D quality of life score, or satisfaction. ID patients had a significantly higher rate of undergoing a repeat operation at three months (4.9% vs. 1.5%, p=0.015).
The researchers believe that this data “can provide surgeons with additional information when counselling patients on the pros and cons of ID versus DD surgery”.