Knee instruments and rating scales designed to measure outcomes

In this article, the knee instruments and rating scales that are designed to measure outcomes are revised. Although the International Knee Documentation Committee Subjective Knee Form can be used as a general knee measure, no instrument is currently universally applicable across the spectrum of knee disorders and patient groups. Clinicians and researchers looking to use a patient-based score for measurement of outcomes must consider the specific patient population in which it has been evaluated. The Western Ontario and McMaster Universities Osteoarthritis Index is recommended for the evaluation of treatment effect in persons with osteoarthritis (OA). This is a generic health status questionnaire that contains 36 items, is widely used, and easy to complete. The Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire evaluates the functional status and quality of life (QoL) of patients with any type of knee injury who are at increased risk of developing OA; i.e., patients with anterior cruciate ligament (ACL) injury, meniscus injury, or chondral injury. So far, the KOOS questionnaire has been validated for several orthopedic procedures such as total knee arthroplasty, ACL reconstruction, and meniscectomy. The utilization of QoL questionnaires is crucial to the adequate assessment of a number of orthopedic procedures of the knee. The questionnaires are generally well accepted by the patients and open up new perspectives in the analysis of prognostic factors for optimal QoL of patients undergoing knee surgery

Total knee replacement; minimal clinically important differences and responders

SummaryObjectiveTo provide new data on minimally clinical important difference (MCID) and percentages of responders on pain and functional dimensions of Western Ontario and McMaster Osteoarthritis Index (WOMAC) in patients who have undergone total knee replacement (TKR).Methods1-year prospective multicentre study with two different cohorts. Consecutive patients on the waiting list were recruited. There were 415 and 497 patients included. Pain and function were collected by the reverse scoring option of the WOMAC (0–100, worst to best). Transition items (five point scale) were collected at 1-year and MCID was calculated through mean change in patients somewhat better, Receiver Operating Characteristic (ROC) and two other questions about satisfaction. Analysis was performed in the whole sample and by tertiles of baseline severity. Likewise were calculated the percentages of patients who attained cut-off values.ResultsGlobal MCID for pain were about 30 in both cohorts and 32 for. By ROC these values were about 20 and 24 respectively. According to the other two transitional questions these values were for pain 27 and 20 for function. By tertiles the worst the baseline score the higher the cut-off values. Percentage of responders does not change when comparing responders to the global MCID with their own tertile MCID and were about 61% for pain and 50% for function.ConclusionDue to the wide variations, MCID estimates should be calculated and used according to the baseline severity score