Patients with osteoarthritis (OA) of the hip with a Kellgren-Lawrence radiological grade of III or IV, a high mean global assessment during the first 6 months, and previous treatment with nonsteroidal anti-inflammatory drugs (NSAIDs) were among the most likely to undergo total hip replacement (THR) surgery, according to a prospective 2-year study published in the Annals of Rheumatic Diseases.1
"It is not only structural severity, but also prolonged symptoms and, in particular, pain and intake of NSAIDs (a surrogate marker of symptomatic severity), [which] are good predictors of THR," lead researcher Laure Gossec, MD, rheumatologist with the Service de Rhumatologie B at the Hôpital Cochin in Paris, France, tells CIAOMed. "These patients should be carefully monitored and optimally treated."
Of 505 patients available for follow-up at 2 years, 37.4% underwent their first hip replacement. According to multivariate analysis, the main predictors were Kellgren-Lawrence radiographic grade III or IV, a high mean patient global assessment during the first 6 months (as assessed by visual analog scale [VAS] and physical function subscale of the Western Ontario and McMaster Universities Osteoarthritis [WOMAC] Index), and previous NSAID use.
Specifically, patients with two of these factors had an odds ratio of 3.0 for undergoing hip replacement and, if all three of these predictors were present, a patient had a 63% probability of hip replacement, Dr. Gossec and colleagues report.
The new study did have a high rate of loss to follow-up, the researchers point out. In fact, 15.5% of the original 741 enrollees were lost to follow-up. Still, baseline characteristics of patients lost to follow-up did not differ from those patients who completed the study, which reduces the risk of bias, they note.
While other studies have shown that weight loss can decrease the likelihood of joint replacement and/or help patients delay considering the procedure, Dr. Gossec says that this study "does not allow me to specifically answer questions concerning weight loss, but these patients should benefit from the largest treatment measures including, of course, nonpharmacological measures."
Obese surgical candidates fair worse
In a related study, published in the journal Clinical Orthopaedics and Related Research,2 researchers from Brigham and Women's Hospital in Boston found that those patients with diabetes, hypertension, or obesity were significantly more likely to suffer postoperative complications when undergoing joint replacement surgery, compared with their counterparts without such risk factors. Specifically, obesity conferred the highest risk of postoperative complications and the need for additional postdischarge care, the study showed.
"Hypertension, diabetes, and obesity are important independent predictors of increased complications for patients undergoing major joint replacement surgery," Nitin Jain, MD, postdoctoral fellow at Brigham and Women's Hospital, Harvard Medical School in Boston, offered in a written statement. Dr. Jain conducted the study as a research associate in the laboratory of Laurence Higgins, MD, orthopaedic surgeon at Duke University Medical Center in Durham, North Carolina.
"The results of our study should [help] surgeons to more accurately predict which of their patients are most likely to have adverse outcomes after their surgery," Dr. Jain says. "With this knowledge, surgeons should not only be able to better counsel their patients before surgery, but also consider strategies during and after surgery to ensure better outcomes. However, the risks and benefits of a joint-replacement procedure should be weighed by surgeons on an individual patient basis."
Strategies may include better control of glucose and blood pressure during surgery for patients with diabetes and hypertension and/or the use of postoperative anticoagulant therapy to prevent deep vein thrombosis, Dr. Jain and colleagues observe.
Specifically, 3.7% of obese patients experience in-hospital complications, compared with 2.6% for nonobese patients, and 2.8% of hypertensive patients suffered in-hospital complications, compared with 2.6% for nonhypertensive patients. For patients with and without diabetes, the in-hospital complication rates were 2.9% and 2.6%, respectively.
The likelihood of a "nonroutine" discharge from the hospital was 30% higher for diabetics and 45% higher in obese patients-for patients with diabetes who were also obese, the likelihood rose to 75%. Nonroutine discharges are those in which a patient is referred to another facility where further care is necessary. The analysis included 959,839 patients who received knee, hip, or shoulder replacements between 1988 and 2000.
References:
- Gossec L, Tubach F, Baron G, et al. Predictive factors of total hip replacement due to primary osteoarthritis: a prospective 2 year study of 505 patients. Ann Rheum Dis. 2005;64:1028-1032.
- 2. Jain N, Guller U, Pietroban R, et al. Comorbidities increase complication rates in patients having arthroplasty. Clin Orthop Relat Res. 2005;435:232-238.