What Are the Odds of Pseudarthrosis in Smokers?

Odds of a pseudoarthrosis or nonunion are high and are most likely to occur at the L5-S1 level and in smokers, according to a new study.

The study, “Pseudarthrosis Following Lumbar and Lumbosacral Fusion Using the Antepsoas Technique,” was published in the February 2022 issue of the journal Spine.

The researchers evaluated the prevalence of pseudarthrosis after antepsoas lumbar and lumbosacral fusions.

“Pseudarthrosis is a feared complication following spinal fusions and may affect their clinical outcomes. To date there are no sufficient data on the fusion rate following antepsoas lumbar and lumbosacral arthrodesis,” the researchers wrote.

The retrospective review collected data for 220 patients who had been surgically treated between January 2008 and February 2019. The researchers graded fusion using CT scans imaging and adopting a 1-4 grading scale where 1 meant definitely fused and a grade 3 or 4 indicated pseudarthrosis.

Of the 220 patients, 8 developed pseudarthrosis. Of the 693 discs that were treated with the antepsoas technique, 681 or 98.3% were considered fused.

The researchers noted the highest rate of pseudarthrosis was found at L5-S1 compared with L1-L5 discs. Six out of the 127 smokers (5%) included in the study developed pseudoarthrosis. Only four were symptomatic, however. And two needed revision surgery. The overall revision rate related to pseudarthrosis was 0.9%.

“The minimally-invasive surgery-antepsoas technique results in a high fusion rate (96.4% of patients, 98.3% levels). Pseudarthrosis was noted mostly at the L5-S1 discs and in smokers,” the researchers reported.

Study authors included Chadi Tannoury, M.D., Rahul Bhale, Molly Vora, Aziz Saade, M.D., Rabih Korthawi, M.D., Giuseppe Orlando, M.D., Avilash Das and Tony Tannoury, M.D., all of the Boston Medical Center in Boston, Massachusetts.