Total knee arthroplasty patients are trending younger and heavier, while Medicare and Medicaid recipients who undergo total hip arthroplasties run a higher risk of needing revision surgeries, according to a pair of recent studies.
For the knee arthroplasty study, researchers culled the Mayo Clinic’s Total Joint Registry for data from 1993 to 2005 on patient demographics, underlying diagnosis, medical and psychological comorbidities and exam findings.
The results, published online May 27 in the journal Arthritis Care & Research, showed that 55% of the 7,229 TKA patients reviewed were women. The mean age decreased -1.9%, from 69.3 to 68.0 years, even as mean body-mass index scores rose 5.6%, to 31.8 kg/m2.
The mean score on the Charlson-Deyo Index, which predicts 10-year mortality for patients with comorbid conditions, increased by 36% (1.1 to 1.5) over the 13-year study period, according to the study.
"Compared with 1993–1995, significantly more patients (by 2–3 times) in 2002–2005 had a BMI ≥40 kg/m2 (4.8% versus 10.6%), age <50 years (2.9% versus 5.2%), Charlson-Deyo Index of ≥3 (12% versus 22.3%), depression (4.1% versus 14.8%), and anxiety (4.1% versus 8.9%), and significantly fewer patients had an underlying diagnosis of rheumatoid/inflammatory arthritis (6.4% versus 1.5%; P < 0.001 for all)," the researchers wrote. "Compared with 1993–1995, significant reductions were noted in 2002–2005 for the physical examination findings of anteroposterior knee instability, mediolateral knee instability, moderate to severe knee synovitis, severe limp, fair or poor muscle strength, and absent peripheral pulses (P ≤ 0.001 for all)."
For the hip arthroplasty study, another set of researchers looked at data from 207,256 patients who underwent primary THA between 1997–2005 in California and New York. Their study found that patients covered by Medicare and Medicaid were 24% and 91%, respectively, more likely to need early septic revision than privately insured patients. Women were 29% less likely than men to undergo early septic revision, according to the study, also published online May 27 in Arthritis Care & Research.
"The probabilities of undergoing early aseptic revision and early septic revision were 4% and <1% at 5 years, respectively," the researchers wrote. "A number of identifiable factors, including younger age, Medicaid, and low hospital volume, increase the risk of undergoing early revision THA. Patient-level characteristics distinctly affect the risk of revision within 10 years, particularly if due to infection. Our findings reinforce the need for continued investigation of the predictors of early failure following THA."