Tuesday, February 21, 2017

Total joint replacement and smoking don't mix.

Smoking Increases the Rate of Reoperation for Infection within 90 Days After Primary Total Joint Arthroplasty

These authors sought to investigate the association between smoking and readmission and/or reoperation within 90 days of total joint arthroplasty among 15,264 patients (6,749 male and 8,515 female)  who underwent 17,394 primary total joint arthroplasties between 2000 and 2014. Of these patients, 1,371 (9.0%) were current smokers, 5,195 (34.0%) were former smokers, and 8,698 (57.0%) were nonsmokers. Former smokers reported a median of 22.2 years (range, 0.2 to 60 years) of abstinence prior to the surgical procedure.

Current smokers were significantly younger (57.7± 10.3 years) than nonsmokers (63.2± 11.8 years). 

Current smokers were significantly more likely than nonsmokers to undergo reoperation for infection (odds ratio [OR], 1.82 [95% confidence interval (CI), 1.03 to 3.23]; p = 0.04). 
Former smokers were not at significantly increased risk (OR, 1.11 [95% CI, 0.73 to 1.69]; p = 0.61). 

Packs per decade were independently associated with an increased risk of 90-day nonoperative readmission regardless of smoking status (OR, 1.12 [95% CI, 1.03 to 1.20]). 

Comment: This well controlled study indicates that in this cohort, active smoking almost doubled the risk of reoperation for infection. In that total joint arthroplasty is an elective procedure and in that smoking is a voluntary activity, surgeons need to consider whether it is reasonable to perform joint replacement on active smokers. We suggest that smoking is not only directly harmful to the patient's health, but it is also an indication of a patient's voluntary disregard for their own well-being.

We've discussed this phenomenon in prior posts:

These authors reviewed 1834 shoulders in 1614 patients (814 smokers and 1020 nonsmokers) having primary TSA or RSA at the Mayo Clinic between 2002 and 2011 and had a minimum 2-year follow-up. Smoking status was assessed at the time of surgery: non-smokers, former smokers (no smoking in the month before surgery), and current smokers (smoking within a month before surgery).

Complications occurred 4% of the cases, 5.4 % in smokers and 3.0 % in non smokers.

Multivariable analyses showed that
-in comparison to non-smokers, the risk of periprosthetic infection was 7.3 times higher in current smokers and 4.6 times higher in former smokers.
-in comparison to non-smokers, the risk of postoperative fracture was 7 times higher in current smokers.

The overall complication-free survival rate for the three groups is shown below.

Comment: It is of interest that 44% percent of the patients in this series were classified as smokers. It is also of interest that the risk of postoperative fracture was dramatically less in those that had stopped smoking a month or more prior to surgery, whereas the effect of smoking cession was less pronounced for the risk of infection.

Smoking has often been made to seem glamorous
but it not only compromises health, but also is a marker for individuals that tend to put themselves at increased risk. 

The interested reader will also want to check out these two related posts:
Cigarette smoking affects bone, cuff repair, surgical risk and more
Pain and smoking

as well as this article:

Tobacco use is associated with increased rates of infection and revision surgery after primary superior labrum anterior and posterior repair.

These authors used the PearlDiver Patient Records Database, a for-fee insurance-based database of patient records, to explore the relationship between tobacco use and the adverse outcomes of arthroscopic superior labrum anterior and posterior (SLAP) repairs. The cohort of primary SLAP repairs was then divided into tobacco use and non–tobacco use cohorts using ICD-9 code 305.1 (tobacco use disorder). It is not known how accurate this coding is and how it reflects the different uses of tobacco (inhaled, chewed, etc).

They found that the incidences of revision SLAP repair or revision to a biceps tenodesis (P = .023) and postoperative infection (P = .034) were significantly higher in patients who used tobacco versus matched controls.

They suggest that tobacco’s negative effects on poor wound healing and the development of postoperative infection may results from a combination of factors. "On a cellular level, tobacco use reduces cutaneous blood flow, impairing soft tissue oxygenation, resulting in increased anaerobic metabolism in healing tissues. Simultaneously, thrombi are generated as a result of increased platelet aggregation, which compounds an already hypoxic environment, leading to decreased healing potential. This reduced perfusion impairs the delivery of critical lymphocytes to areas undergoing healing or prone to infection. Furthermore, systemic nicotine has been shown to have a negative immunomodulatory effect on T-cell function, resulting in cells that are more susceptible to infectious pathogens. Finally, and perhaps most specific to tendon healing required for a successful SLAP repair, the synthesis of collagen has been shown to be greatly impeded in smokers, leading to impaired wound and soft-tissue healing."

Comment: The same factors that impair success in SLAP repairs must apply to the healing of rotator cuff repairs, Bankart repairs and subscapularis healing in In addition to its effect on healing (see this link), tobacco use is also associated with increased pain (another cause of 'surgical failure')  as shown here and here .

The prior post also emphasizes the risk.

There is another association of importance than may account for some of the surgical failures in smokers, and that is the observation that smokers tend to take more risks than non-smokers (see this post). Here is a compelling quote from that article.

"The fact that smoking is bad for people’s health has become common knowledge, yet a substantial amount of people still smoke. Previous studies that sought to better understand this phenomenon have found that smoking is associated with the tendency to take risk in other areas of life as well. The current paper explores factors that may underlie this tendency. An experimental analysis shows that smokers are more easily tempted by immediate high rewards compared to nonsmokers. Thus the salience of risky alternatives that produce large rewards most of the time can direct smokers to make bad choices even in an abstract situation such as the Iowa Gambling Task. These findings suggest that the risk taking behavior associated with smoking is not related to the mere pursuit of rewards but rather reflects a tendency to yield to immediate temptation."

Now here's a quiz. This paper comes from Virginia. Can you name the top five tobacco producing states in order? The answer can be found here.