A number of studies have demonstrated poor outcomes after total joint arthroplasty (TJA) for patients who smoke, have high hemoglobin A1c (HbA1c), and have high BMI. Therefore, clinical guidelines now suggest optimizing patients for these factors before undergoing total knee or hip arthroplasty to reduce complications.
However, some research shows that when these guidelines are applied inflexibly, patients who have lower socioeconomic status, are racial/ethnic minorities in the U.S., or are female are disproportionately excluded from surgery. Therefore, some centers don’t strictly enforce the guidelines when selecting candidates for TJA.
Researchers at Brigham and Women’s Hospital have become the first to examine the sociodemographic characteristics of patients who don’t meet the guidelines and their rates of postoperative complications. They found that those who don’t meet guidelines have twice the risk of experiencing complications compared with patients who are nonsmokers and meet suggested thresholds for HbA1c and BMI.
Adriana P. Liimakka, MBI, a student at Harvard Medical School and a research assistant in the Department of Orthopaedic Surgery at the Brigham, Antonia F. Chen, MD, MBA, chief of Arthroplasty and Joint Reconstruction in the Department, and colleagues report in The Journal of Bone & Joint Surgery.
Methods
The team analyzed data on 11,611 adults who underwent primary total knee (59%) or hip (41%) arthroplasty across a network of tertiary hospitals in Massachusetts between January 1, 2010, and December 31, 2020.
89% of patients were considered to meet clinical guidelines for TJA because they had HbA1c <8.0%, BMI <40 kg/m2, and were not currently smoking.
A complication was defined as a surgical intervention after primary TJA that involved the same joint and concerned the internal prosthesis. Complications were categorized as either infectious or noninfectious (the latter included periprosthetic fracture, fibrosis, a broken prosthesis, instability, and prosthetic loosening).
Characteristics of the Group That Did Not Meet Guidelines
Factors associated with a higher risk of not meeting guidelines at the time of TJA were:
- Black race—OR, 1.60 (P=0.001)
- Medicaid coverage—OR, 1.75 (P=0.001)
- Medicare coverage—OR, 1.22 (P=0.007)
Older age was associated with less risk of not meeting guidelines (OR, 0.94; P<0.001). There was no association between osteoarthritis severity and not meeting guidelines.
All analyses were controlled for surgeon bias, the statistical tendency of surgeons to be more or less likely to perform surgery regardless of guideline adherence.
Postoperative Outcomes
Patients who did not meet guidelines had a higher overall risk of complications than those who did meet guidelines (7.7% vs. 5.9%; P=0.017). They were also at higher risk of the subgroup of infectious complications (3.1% vs. 1.4%; P<0.001).
On adjusted analyses, an increased rate of complications was associated with:
- Not meeting guidelines—OR, 2.08 (P=0.001)
- Black race—OR, 1.94 (P<0.001)
- Medicare coverage—OR, 1.35 (P=0.001)
Not meeting clinical guidelines explained 13% of the difference between Black and white patients in overall complications (P=0.040), 12% of the difference between Hispanic and white patients in overall complications (P< 0.001), 23% of the difference between Black and white patients in infectious complications (P=0.02), and 8% of the difference between Hispanic and white patients in infectious complications (P=0.04).
Patient Counseling
This evidence suggests patients who do not meet clinical guidelines for TJA eligibility should be fully informed about their increased risk of complications. The shared decision-making process between patients and surgeons should determine whether surgery is the best choice for their goals.
Where indicated, patients could be referred to optimization interventions that encourage weight loss, smoking cessation, and blood glucose control. These have been shown to be cost-effective in managing relevant comorbidities and mitigating their effects on postoperative outcomes.