Smokers at Increased Risk of Reoperation for Infection after TJA
For patients undergoing total hip arthroplasty (THA) or total knee arthroplasty (TKA), smoking is associated with an increased risk of infectious complications requiring repeat surgery, according to a study in the February 15 issue of The Journal of Bone & Joint Surgery.
“Our results found that current smokers had a significantly higher rate of septic reoperation compared with non-smokers,” said senior author Matthew S. Austin, MD, of The Rothman Institute at Thomas Jefferson University, Philadelphia, Pennsylvania.
“Furthermore, each additional pack-year significantly contributed to total reoperations.”
The researchers looked at how smoking history affected the risk of hospital readmissions among patients undergoing either THA or TKA. The study included data on a total of 17,394 procedures (15,264 patients) performed between 2000 and 2014 — 8,917 hip and 8,477 knee replacements.
At the time of surgery, 9% of patients were current smokers, 34% were former smokers, and 57% were non-smokers. Current smokers were younger than non-smokers, with an average age of 58 versus 63 years, respectively. Smokers also had higher rates of certain major respiratory and cardiovascular diseases.
The absolute risk of reoperation for infectious complications within 90 days was low at 0.71%. However, this risk was substantially higher for current smokers: 1.2%, compared with 0.56% for non-smokers.
After adjustment for other characteristics, current smokers remained at significantly increased risk of reoperation for infectious complications: The relative risk was 80% higher for current smokers than for non-smokers. As a group, former smokers were not at increased risk.
However, for current and former smokers alike, the risk of 90-day non-operative readmission increased with the number of “pack-years” smoked. Smoking an extra pack per day for a decade was associated with a 12% increase in that relative risk.
Smoking overall, however, was unrelated to the risk of readmission without surgery or for reoperation for reasons other than infections.
Although there was no difference in the total readmission rate, the study findings suggest that current smokers are at substantially higher risk of reoperation for septic complications. Patients with a history of heavier smoking are also at increased risk, even if they have since quit smoking.
“If smoking is associated with elevated perioperative risk of readmission and/or reoperation, then it may be reasonable to engage the patient in a smoking cessation program prior to total joint arthroplasty,” Dr. Austin and coauthors write.
However, further studies would be needed to determine whether quitting smoking before total joint arthroplasty can reduce the risk of complications.
Tischler EH, Ko LM, Chen AF, Maltenfort MG Schroeder J, Austin MS. Smoking increases the rate of reoperation for infection within 90 days after primary total joint arthroplasty. J Bone Joint Surg Am, 2017 Feb 15; 99 (4): 295 -304. doi: https://doi.org/10.2106/JBJS.16.00311