Muscle Strength and Total Knee Replacement

Study Overview
=================
Brief Summary
-----------------
Purposes: To compare knee extensor muscle strength, physical function and self-reported function before and after total knee replacement with healthy age-matched controls. To describe changes in knee extensor muscle strength up to one year after surgery. To study the relationship between changes in knee extensor muscle strength and changes in physical function, self-reported function and physical activity level and the relationship between changes in knee extensor muscle strength and satisfaction. Methods: A prospective observational study and comparison with controls. 50-55 individuals aged 65 or older, scheduled for total knee arthroplasty will be recruited to the study group. Measurement of study group 0-2 weeks before surgery and 3, 6 and 12 months following surgery. Comparison with 50-55 healthy age-matched controls.

Official Title
-----------------
Knee Extensor Muscle Strength and Physical Function Before and After Total Knee Replacement

Conditions
-----------------
Arthropathy of Knee, Osteo Arthritis Knee

Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Scheduled for total knee replacement on the basis of osteoarthritis of the knee Expected rehabilitation in a primary care setting Exclusion Criteria: Difficulties reading or speaking Swedish Revision surgery Rehabilitation in other settings than primary care

Ages Eligible for Study
-----------------
Minimum Age: 65 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Study group<br>Patients scheduled for total knee replacement. | |
| Control<br>Healthy age-matched controls. | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in knee extensor muscle strength of the affected side from before surgery to one year after surgery | Maximum voluntary isometric contraction measured using the make method with hand-held dynamometry fixated in a knee extension strength training apparatus. Force measurement in Newtons. | Comparison of data before surgery (0-2 weeks) with data 3, 6 and 12 months after surgery | 
| Comparison of knee extensor muscle strength of the affected side before surgery with controls | Maximum voluntary isometric contraction measured using the make method with hand-held dynamometry fixated in a knee extension strength training apparatus. Force measurement in Newtons. | Comparison of data before surgery (0-2 weeks) with data data from the control group | 
| Comparison of knee extensor muscle strength of the affected side one year after surgery with controls | Maximum voluntary isometric contraction measured using the make method with hand-held dynamometry fixated in a knee extension strength training apparatus. Force measurement in Newtons. | Comparison of data one year after surgery with data data from the control group | 
| Comparison of knee extensor muscle strength of the affected side with the unaffected side | Maximum voluntary isometric contraction measured using the make method with hand-held dynamometry fixated in a knee extension strength training apparatus. Force measurement in Newtons. | Before surgery (0-2 weeks). 3, 6 and 12 months after surgery. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Comparison of 30 s chair stand test between study group and control group | 30 s chair stand test measures the number of complete stands the test person is able to perform within 30 s. | Comparison of data for the study group from before surgery (0-2 weeks) and 12 months after surgery with data from the control group | 
| Comparison of Knee injury and Osteoarthritis Outcome Score between study group and control group | Knee Injury and Osteoarthritis Outcome Score is a self-reported outcome questionnaire that measures 5 sub-scales: pain, other symptoms, function in daily living, function in sport and recreation and knee-related quality of life. | Comparison of data for the study group from before surgery (0-2 weeks) and 12 months after surgery with data from the control group | 
| Comparison of 6-min walk test between study group and control group |  | Comparison of data for the study group from before surgery (0-2 weeks) and 12 months after surgery with data from the control group | 
| Correlation between changes in knee extensor muscle strength of the affected side before and after surgery with changes in 30 s chair stand test, Knee injury and Osteoarthritis Outcome Score, 6-min walk test and physical activity level | Physical activity level will be measured as activity minutes using a questionnaire. | Before surgery (0-2 weeks) and 12 months after surgery | 
| Correlation between changes in knee extensor muscle strength of the affected side before and after surgery with overall satisfaction one year after surgery | Satisfaction will be measured using a 4-point likert scale. | Changes in muscle strength from before surgery (0-2 weeks) and 12 months after surgery, satisfaction 12 months after surgery |