The AAHKS Clinical Research Award: What Are the Costs of Knee Osteoarthritis in the Year Prior to Total Knee Arthroplasty?

BACKGROUND: Despite American Academy of Orthopaedic Surgeons Clinical Practice Guidelines (CPGs) related to the non-arthroplasty management of osteoarthritis (OA) of the knee, non-recommended treatments remain in common use. We sought to determine the costs associated with non-arthroplasty management of knee OA in the year prior to total knee arthroplasty (TKA) and stratify them by CPG recommendation status. METHODS: The Humana database was reviewed from 2007 to 2015 for primary TKA patients. Costs for hyaluronic acid (HA) and corticosteroid injections, physical therapy, braces, wedge insoles, opioids, non-steroidal anti-inflammatories, and tramadol in the year prior to TKA were calculated. Cost was defined as reimbursement paid by the insurance provider. Costs were analyzed relative to the overall non-inpatient costs for knee OA and categorized based on CPG recommendations. RESULTS: In total 86,081 primary TKA patients were analyzed and 65.8% had at least one treatment in the year prior to TKA. Treatments analyzed made up 57.6% of the total non-inpatient cost of knee OA in the year prior to TKA. Only 3 of the 8 treatments studied have a strong recommendation for their use (physical therapy, non-steroidal anti-inflammatories, tramadol) and costs for these interventions represented 12.2% of non-inpatient knee OA cost. In contrast, 29.3% of the costs are due to HA injections alone, which are not supported by CPGs. CONCLUSION: In the year prior to TKA, over half of the non-inpatient costs associated with knee OA are from injections, therapy, prosthetics, and prescriptions. Approximately 30% of this is due to HA injections alone. If only interventions recommend by the CPG are utilized then costs associated with knee OA could be decreased by 45%.

Magnetic resonance imaging (MRI) assessment of ventricular remodeling after myocardial infarction in rabbits.

To understand the structure-function relationship in the postinfarcted myocardium in rabbits, we induced cardiac ischemia by ligating the left circumflex coronary artery. Sham controls underwent thoracotomy only. At 7 and 30 d after ligation, cardiac MRI was conducted by using pulse-oxymetry-gated cine acquisition to provide complete phases of the heartbeat. The rabbits were anesthetized under 1.5% isoflurane ventilation, and ultrafast techniques made breath-hold 3D coverage in different cardiac axes feasible. Viability imaging was performed after intravenous injection of 0.15 mmol/kg gadolinium to assess the extent of infarction. Data (n ≥ 6) are presented as mean ± SEM and analyzed by ANOVA and ANCOVA. In postligation rabbits, end-systolic (mean ± SEM, 2.3 ± 0.3 mL) and end-diastolic (4.2 ± 0.4 mL) volumes were increased compared with preligation values (end-systolic, 1.1 ± 0.1 mL; end-diastolic, 2.98 ± 0.2 mL). Ejection fraction was influenced adversely by the presence of scar tissue at both 7 and 30 d after ligation and apparently nonlinear with the heart rate. Cardiac force was increased in the basal region in both end-systole and end-diastole in postligation hearts but progressively decreased toward the apex. Late gadolinium enhancement delineated 15.2 ± 5.8% myocardial infarction at 7 d after ligation and 14.5 ± 5.8% at 30 d, with limited wall motion and wall thinness. Compensatory wall thickening was present in the basal region when compared with that in preligation hearts. MRI offers detailed spatial resolution and tissue characterization after myocardial infarction.