Evaluation of the American Academy of Orthopaedic Surgeons Appropriate Use Criteria for the Nonarthroplasty Treatment of Knee Osteoarthritis in Veterans

Data collected included race, gender, duration of nonarthroplasty treatment, BMI, and Kellgren-Lawrence classification of knee OA at time of presentation for symptomatic knee OA.¹¹ All AAOS AUC-evaluated nonarthroplasty treatments utilized prior to arthroplasty intervention also were recorded (Table 1). 

Indications and classifications for each subject were entered into the AAOS AUC online algorithm, and every AAOS AUC evaluated treatment utilized was assigned a rating of appropriate, may be appropriate, or rarely appropriate, based on the algorithm results for that clinical scenario (Table 2). 

Information regarding anti-inflammatory, analgesic, and prescribed oral or transcutaneous opioid use for chronic knee pain during the period of nonoperative management of knee OA prior to TKA was obtained by review of medication lists and reconciliation with orthopaedic consultation notes in the electronic health record. Peri-operative anti-inflammatory, analgesic, and prescribed oral or transcutaneous opioid use did not constitute an AUC intervention.

Statistical Analysis

Statistical analysis was completed with GraphPad Software Prism 7.0a (La Jolla, CA) and Mathworks MatLab R2016b software (Natick, MA). Univariate analysis with Student t tests with Welch corrections in the setting of unequal variance, Mann-Whitney nonparametric tests, and Fisher exact test were generated in the appropriate setting. Multivariable analyses also were conducted. For continuous outcomes, stepwise multiple linear regression was used to generate predictive models; for binary outcomes, binomial logistic regression was used.

Factors analyzed in regression modeling for the total number of AAOS AUC evaluated nonarthroplasty treatments utilized and the likelihood of receiving a rarely appropriate treatment included gender, race, function-limiting pain, range of motion (ROM), ligamentous instability, arthritis pattern, limb alignment, mechanical symptoms, BMI, age, and Kellgren-Lawrence grade. Factors analyzed in timing of TKA included the above variables plus the total number of AUC interventions, whether the patient received an inappropriate intervention, and average appropriateness of the interventions received. Residual analysis with Cook’s distance was used to identify outliers in regression. Observations with Cook’s distance > 3 times the mean Cook’s distance were identified as potential outliers, and models were adjusted accordingly. All statistical analyses were 2-tailed. Statistical significance was set to P ≤ .05 for all outputs.

Results

In the study, 97.8% of participants identified as male, and the mean age was 62.8 years (Table 3). 

The study group was predominantly white (70.3%). All participants had a diagnosis of primary OA. The majority of patients were aged 51 to 70 years (68.1%) and presented with pain occurring following short-distance ambulation (79.1%) but without mechanical symptoms (80.2%). On examination, the majority of patients were found to have full knee ROM (53.8%), no ligamentous instability (97.8%), and normal limb alignment (60.4%). Radiographically, patients most often had multicompartmental disease (69.2%) with evidence of severe joint-space narrowing (63.7%), resulting in a plurality of patients having a Kellgren-Lawrence arthritis grade of 3 (46.2%) (Table 4).

Appropriate Use Criteria Interventions

Patients received a mean of 5.2 AAOS AUC evaluated interventions before undergoing arthroplasty management at a mean of 32.3 months (range 2-181 months) from initial presentation. The majority of these interventions were classified as either appropriate or may be appropriate, according to the AUC definitions (95.1%). Self-management and physical therapy programs were widely utilized (100% and 90.1%, respectively), with all use of these interventions classified as appropriate.