Validation of a second-generation appropriateness classification system for total knee arthroplasty: a prospective cohort study

Abstract

Background To test the validity of a second-generation appropriateness system in a cohort of patients undergoing total knee arthroplasty (TKA). Methods We applied the RAND/UCLA Appropriateness Method to derive our second-generation system and conducted a prospective study of patients diagnosed with knee osteoarthritis in eight public hospitals in Spain. Main outcome questionnaires were the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Short-Form-12 (SF-12), and the Knee Society Score satisfaction scale (KSS), completed before and 6 months after TKA. Baseline, changes from baseline to 6 months (journey outcome), and 6-month scores (destination outcome) were compared according to appropriateness category. Percentage of patients attaining the minimal clinically important difference (MCID) and responders according to Outcome Measures in Rheumatology-Osteoarthritis Research Society (OMERACT-OARSI) criteria were also reported. Results A total of 282 patients completed baseline and 6-month questionnaires. Of these, 142 (50.4%) were classified as Appropriate, 90 (31.9%) as Uncertain, and 50 (17.7%) as Inappropriate. Patients classified as Appropriate had worse preoperative pain, function, and satisfaction (p < 0.001) and had greater improvements (i.e., journey scores) than those classified as Inappropriate (p < 0.001). At 6 months, destination scores for pain, function, or satisfaction were not significantly different across appropriateness categories. The percentage of patients meeting responder criteria (p < 0.001) and attaining MCID was statistically higher in Appropriate versus Inappropriate groups in pain (p = 0.04) and function (p = 0.004). Conclusions The validity of our second-generation appropriateness system was generally supported. The findings highlight a critical issue in TKA healthcare: whether TKA appropriateness should be driven by the extent of improvement, by patient final state, or by both.

Patient appropriateness for total knee arthroplasty and predicted probability of a good outcome

“…There is strong consensus that TKA should be offered to individuals with knee symptoms that are negatively affecting quality of life despite a trial of non-surgical therapies. 15 16 25–27 However, only 71% of our TKA recipients had received recommended OA therapies. Although we did not find that receipt of prior recommended OA therapies was associated with TKA outcome, it is reasonable to expect that non-surgical therapies have been exhausted before a costly and potentially risky procedure is performed.…”

“… 15 16 18 Using the Spanish criteria, Escobar et al found that appropriate candidates were more likely than those deemed inappropriate to experience minimally important improvements in pain and function at follow-up, but outcomes were similar for those deemed appropriate versus uncertain and level of satisfaction was similar across groups. 15 Furthermore, both the Spanish and AAOS criteria ask surgeons to make assumptions regarding the patients whose TKA appropriateness they are assessing. In development of the Spanish criteria, experts were instructed to assume that the patient had unilateral knee symptoms, a BMI<40 kg/m 2 , adequate social support and received appropriate knee OA management and their expectations had been addressed appropriately.…”

“…Thus, TKA appropriateness criteria should be used to determine if it is reasonable to consider operating given a patient’s particular circumstances 12 13. Yet, to date, there has been little or no involvement of patients with knee OA in the development or validation of TKA appropriateness criteria or decision-support tools 14–18. Most have been developed based on expert clinician consensus informed by the best available scientific evidence 9 15 16 18–20.…”

“…Yet, to date, there has been little or no involvement of patients with knee OA in the development or validation of TKA appropriateness criteria or decision-support tools 14–18. Most have been developed based on expert clinician consensus informed by the best available scientific evidence 9 15 16 18–20. Existing tools generally consider patients’ symptoms, comorbidity, radiographic severity and clinical examination (knee mobility and stability) 17 21.…”

Patellar retraction versus eversion on functional outcomes in total knee replacement: a randomized controlled study protocol

“…Short-term outcomes were as follows: operation time, length of hospital stay, and straight leg raising time. Long-term clinical effect mainly including Insall-Salvati ratio; range of motion at 1 month, 3 months, and 1 year following TKR; and visual analog scale (VAS) at 1 month, 3 months, and Knee Society Score (KSS) score [ 12 , 13 ] at 1 year following TKR. The ISR Insall-Salvati ratio is the ratio between the length of the patellar tendon and length of the patella.…”