Multi-variable Prediction Model of Total Knee Replacement Outcome

Study Overview
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Brief Summary
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Total knee arthroplasty (TKA) is a surgical procedure applied as a common solution to overcome limitations produced by advanced stages of severe gonarthrosis. The procedure has high prevalence, high associated costs, and is considered to be cost-effective. Rehabilitation is essential to optimize outcomes. However, in clinical practice, the length of rehabilitation for each patient may be highly variable, and the programmed times may lack the necessary objectivity. Current limitation of resources and increasing prevalence make essential to generate strategies to optimize surgical results, so that the use of resources of the health system is efficient without detriment to the patient's benefit. For this purpose, objective and pragmatic information must be available, and should be based on scientific evidence in order to assist in making clinical decisions. Indeed, a number of demographic, biomedical and psychosocial factors have been identified as predictors of TKA results (i.e weight, age, expectations...). Some of them have been associated with the need for hospital resources after surgery. However, most researches base their predictions in retrospective studies, which are limited in the type of variables that can be used (clinic history), quality of registries, and limitations of retrospective designs. On the other hand, most of prospective researches base their predictions in a limited number of outcomes. To overcome this limitations, this project has been designed as a prospective observational study with two observations of each patient. The primary goal is to implement a multi-variable prediction model of TKA outcome, so that the procedure become optimal in two aspects : patient recovery (social and economic benefit) and use of health system resources (economic benefit). The implementation requires a processing of the information sampled through various algorithms and innovative data processing in this field, based on data mining and machine learning techniques. This will be used in search of the model with the greatest predictive capacity. As a secondary objective, information extracted from patients both in the final stages of the condition, and in the medium term after the intervention will allow to study the functional and psychosocial reality of the subjects with knee osteoarthritis.

Official Title
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Modelo de predicción Multivariable de Resultados de Artroplastia Total de Rodilla

Conditions
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Knee Osteoarthritis, Joint Disease, Total Knee Replacement, Arthroplasty Complications

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Over 60 years old Severe knee osteoarthritis In the surgery waiting list for undergoing total knee replacement surgery Exclusion Criteria: Lobo Mini-mental State examination < 20 (not able to properly understand the tests and study) Vestibular affection that prevents to perform the tests

Ages Eligible for Study
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Minimum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Length of stay | Length of in-hospital rehabilitation | change from preoperative assessment to six months after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Oxford knee Score (OKS) | Patient Reported Outcome questionnaire to specifically assess the patient's perspective of outcome following Total Knee Arthroplasty. The OKS consists of twelve questions covering function and pain associated with the knee. Each question is scored from 0 to 4 (0 being the worst outcome and 4 being the best). The overall score is the sum of all items and can range from 0 to 48, with higher scores corresponding to better outcomes | change from preoperative assessment to six months after surgery | 
| International Physical Activity Questionnaires (IPAQ-short form) | This measure assesses the types of intensity of physical activity and sitting time that people do as part of their daily lives. It consists of open-ended questions surrounding individuals' last 7-day recall of physical activity. Total physical activity is estimated in metabolic (MET) MET-min/week and time spent sitting. Then three level or categories are proposed (1=low, 2=moderate and 3=high level of physical activity) | change from preoperative assessment to six months after surgery | 
| Euro Quality of Life 5D questionnaire (EQ-5D) | This is a measure of health-related quality of life. The EQ-5D consists of a descriptive system and the EQ VAS. The descriptive system comprises five dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/depression, with 3 possible answers; the score is obtained from the possible binary combination of answers, and interpreted using the visual analogue scale validation technique for the Spanish population. | change from preoperative assessment to six months after surgery | 
| Geriatric Depression Scale (GDS) short form | Yesavage Scale. The short form of this questionnaire consists of a 15-item self-report assessment used to identify depression in older adults. Questions are answered yes or no, and results consider and individual to be non depressed (normal<5), probably depressed (mild=5<10) and very likely to ve depressed (severe>10) | change from preoperative assessment to six months after surgery | 
| Visual Analogue Scale (VAS) of Pain | A visual analog scale is used to assess the perceived knee pain. The participant specifies their level of knee pain by indicating a position along a continuous line between 0, no pain, and 10, worse possible pain | change from preoperative assessment to six months after surgery | 
| Expectations (Pain and Function) | The individual is asked: How do you expect to feel after the operation?. The level of expectation is answered with a Likert scale ranging from much worse to much better. | change from preoperative assessment to six months after surgery | 
| Strength | Quadriceps isometric strength as measured with hand-held dynamometer | change from preoperative assessment to six months after surgery | 
| Range of Motion | Knee range of motion as measured in degrees with a telescopic goniometer | change from preoperative assessment to six months after surgery | 
| Timed Up & Go | A timed test used as a measure of mobility and dynamic balance in which the individual raises from an arm-chair, walks three meters, turn round a cone, and go back to sit again | change from preoperative assessment to six months after surgery | 
| Five times sit to stand test | A measure of physical performance. The functional strength of the lower extremities, the transition movements, the balance and the risk of falls are evaluated. The time spent in getting up from a chair for five times is recorded | change from preoperative assessment to six months after surgery | 
| One leg balance test | A measure of static balance. The time the patient is able to stand on one leg keeping balance is recorded | change from preoperative assessment to six months after surgery |