Abstract
An increasing number of total knee arthroplasties (TKAs) are performed on obese patients.
It is imperative to remain up to date on the effect of obesity on surgical outcomes
and reimbursement trends. The purpose of this study was to evaluate the impact different
severities of obesity have on primary and revision TKA, specifically: (1) incidence
and trends over time; (2) annual growth rate; and (3) admission costs from 2010 to
2014. A retrospective review of a large commercial private payer database within the
PearlDiver Supercomputer application (Warsaw, IN) of TKA procedures was conducted.
Patients who underwent TKA and subsequent revision were identified by Current Procedural
Terminology (CPT) and ninth revision International Classification of Disease (ICD-9)
codes. The index procedure was linked with ICD-9 codes for body mass indexes (BMIs)
from <19 to >70. Statistical analysis was primarily descriptive to demonstrate the
revision incidence and reimbursement deviations due to BMI. Compound annual growth
rate (CAGR) was also calculated. Our query returned a total of 87,607 TKA patients
within the study BMI ranges. The majority of patients had a BMI of 40 to 44.9 (12.2%)
and least in the BMI >70 (0.2%) range. BMI of 40 to 44.9 had the highest overall 5-year
mean reimbursement of $11,521 and the highest overall mean 5-year deviation from normal
BMI (19–24) patients of $3,300. The incidence and burden of TKA revision was highest
in patients with a BMI of 60 to 69.9 (21 and 17.3%, respectively). Average 5-year
revision reimbursement and deviation from normal BMI (19–24) was highest in patients
with a BMI of 40 to 44.9 ($13,883 and $4,030, respectively). The number of obese patients
receiving TKA is steadily rising. The cost of treating obese patients rises as BMI
deviates from normal, as does the incidence of revision surgery. Therefore, surgeons
must be active in counseling patients on weight optimization as part of preoperative
standard of care.
Keywords
total knee arthroplasty - revision - obesity - economics