NEW YORK (Reuters Health) – Smoking, COPD and peptic ulcer disease are important risk factors for complications in patients undergoing elective primary total hip replacement (THR) or primary total knee replacement (TKR), researchers report in 2 on-line papers published July 11th and 18th in Arthritis Care & Research.

“Current smoking at the time of elective total hip or knee joint replacement surgery,” Dr. Jasvinder A. Singh told Reuters Health by email, “is associated with a higher risk of pneumonia and surgical site infection after joint replacement, suggesting that quitting should be strongly considered before joint replacement surgery to decrease these complications.”

Dr. Singh of the University of Alabama at Birmingham and colleagues came to this conclusion after examining data on more than 33,000 veterans who underwent THR/TKR. In all, 57% never smoked, 19% were prior smokers and 24% current smokers.

By 30 days, current smokers were significantly more likely than never smokers to have surgical site infections (odds ratio, 1.41). This was also true of pneumonia (odds ratio, 1.53) and stroke (odds ratio, 2.61). One year mortality was also higher (odds ratio, 1.63).

Prior smokers were also significantly more likely than non-smokers to have pneumonia and stroke as well as urinary tract infection. However, their 1-year mortality was not significantly higher.

In the second study, the team sought to assess the association of specific comorbidities with periprosthetic fractures after TKA. They examined data on more than 17,000 such procedures with a mean follow-up of 6.3 years.

There were 188 periprosthetic fractures of which 162 (86%) occurred on postoperative day 90 day or later. In multivariable analyses that simultaneously adjusted for all comorbidities and other variables, both peptic ulcer disease (hazard ratio, 1.87) and COPD (hazard ratio, 1.62) were significantly associated with fractures.

The investigators observe that further study is required to determine whether peptic ulcer disease leads to fractures or whether treatment such as with proton pump inhibitors underlies the relationship.

Smoking is a risk factor for COPD and the researchers note that corticosteroids are commonly used in treatment and have been linked to fracture risk. Studies of this association are underway.

What is known, Dr. Singh concluded, is that “The presence of peptic ulcer disease and chronic obstructive lung disease is associated with higher risk of fractures around the artificial joint prosthesis in patients who have undergone total knee joint replacement. A better management of these comorbidities and their treatments may reduce this risk of fractures.”

Arthritis Care Res 2011.