Weight Loss Intervention Before Total Knee Replacement

University of Aarhus

Status: Completed

Conditions: Obesity; Osteoarthritis, Knee

Treatments: Behavioral: 8 weeks weight loss program, Cambridge.

Study type: Interventional

Funder types: Other; Industry

Identifiers

NCT01469403

TKABMI

Details and patient eligibility

About

The purpose of this study is to compare the efficacy in a group of patients who must follow the current procedure for treatment of artificial knee, compared with a group of patients who must undergo an 8-week weight loss program before surgery. 1 year after surgery the investigators will examine whether there are differences between the two groups' quality of life and functional capacity.

Full description

Background In Denmark the numbers of primary total knee arthroplasty (TKA) operations annually increase. In the year 2000 was performed approximately 2,500 operations and in 2008 was performed more than 7,500 total knee arthroplasty operations, and there appears in all countries to be similar tendency. Meanwhile, the prevalence of overweight and obesity has increased markedly over the last 50 years. Approximately 13% of the Danish population is obese. For several years the association between obesity and knee osteoarthritis (OA) has been recognized, and osteoarthritis is the most frequent indication for total knee arthroplasty(80%).

The purpose of this study is to investigate whether weight loss interventions before primary total knee arthroplasty will improve quality of life and functional level, reduce pain and risk of early and late postoperative complications.

Sample size Significance level is set to 5% by using a 2-sided analysis and the power is set at 80%. Based on an expectation of a difference in patient-reported outcome scores in between the groups at 8%, as measured by SF-36 12 months postoperatively, standard deviation (SD) 13 must be include 41 participants in each group. To allow a drop-out rate of 20% the group size increases to 51 participants in each group. In total 102 participants.

Statistical analysis, The two groups scores at 12 months postoperatively, and the two groups' change in the primary outcome measurer, from 1 week before surgery to 12 months postoperatively, compared with t-test or Mann-Whitney test rang sum depending on data distribution.

Enrollment: 76 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• All patients recommended for primary total knee replacement.
• Body mass index > 30.
• Must be motivated for weight loss.
• Must be able to read and understand Danish.

Exclusion criteria

• Rheumatoid arthritis.
• Patients who are operated on both knees during the project period can only participate once.
• Planned obesity surgery.

Trial design

Primary purpose: Supportive Care

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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76 participants in 2 patient groups

control group

No Intervention group

Description:

Standard procedure for knee arthroplasty

Weight loss program

Active Comparator group

Description:

The intervention program consists of 8 weeks of low-diet, using formula foods, and dietary counseling before surgery. When using formula foods the patients can achieve a quicker weight reduction and a greater reduction in fat mass than using conventional dietetic hypo caloric diet.

Treatment:

Behavioral: 8 weeks weight loss program, Cambridge.