Weight Loss Intervention Before Total Knee Replacement

Weight Loss Intervention Before Total Knee Replacement, a Randomized Controlled Trial

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.

Study Overview

• Status: Completed
• Conditions: Obesity; Osteoarthritis, Knee
• Intervention / Treatment: Behavioral: 8 weeks weight loss program, Cambridge.

Detailed 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.

• Study Type: Interventional
• Enrollment (Actual): 76
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Denmark
  • Aarhus, Denmark, 8000
    • Department of Orthopedics Research Aarhus University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: control group; Standard procedure for knee arthroplasty
Active Comparator: Weight loss program; 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.	Behavioral: 8 weeks weight loss program, Cambridge.; Fast weight losses improve the prognosis for the sustained weight loss. During the first week a dietitian will tutor the participants in formula food diet (The Cambridge Health and Weight plan UK.), followed by seven weeks with control guidance and instruction in healthy eating habits once a week. The guidance by the dietitian will be carried out both on an individual basis and in groups. The goal of the intervention is to achieve a preoperative weight loss of at least 5 to 10% of the patient's body weight, thus improving patient's health before surgery.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
SF-36	A patient reported outcome (PRO). The questionnaire is a tool for measuring health status. The form is used to measure the patient's view of his own health by scoring standardized responses to standardized questions. The schedule consists of 36 questions representing eight health concepts.	Measured 12 months postoperatively.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
6 minutes walk test (6MW).	Used to target the operating level of the patient's daily activities.	Measured 1 week before surgery.
Body composition	Dual energy X-ray absorptiometry (DEXA) can measure total body bone mineral density and obtain accurate measurements of body tissue composition (muscle mass and fat mass). By measuring the body's muscle mass, fat mass and bone mineral density, one can estimate total body fat percentage.	Measured 1 week before surgery.
Bone mineral density (BMD).	Measured by DEXA scan.	Measured 12 months postoperatively.
KOOS	Knee - specific patient-reported outcome that measures the patient's own assessment of knee problems and related problems. The schedule consists of 42 questions representing 5 strands.	Measured 1 week before surgery.
Pain	Visual Analogue Scale (VAS pain score)	Measured 1 week before surgery.
Serum leptin.	Leptin is a hormone produced in fat tissue.	Measured 1 week before surgery.
Heart rate	Cardiovascular complications.	Measured 1 week before surgery.
Blood pressure	Cardiovascular complications.	Measured 1 week before surgery.
6 minutes walk test (6MW).	Used to target the operating level of the patient's daily activities.	Measured 8 week postoperatively.
6 minutes walk test (6MW).	Used to target the operating level of the patient's daily activities.	Measured 12 months postoperatively
Body composition	Dual energy X-ray absorptiometry (DEXA) can measure total body bone mineral density and obtain accurate measurements of body tissue composition (muscle mass and fat mass). By measuring the body's muscle mass, fat mass and bone mineral density, one can estimate total body fat percentage.	Measured 8 week postoperatively
Body composition	Dual energy X-ray absorptiometry (DEXA) can measure total body bone mineral density and obtain accurate measurements of body tissue composition (muscle mass and fat mass). By measuring the body's muscle mass, fat mass and bone mineral density, one can estimate total body fat percentage.	Measured 12 months postoperatively
KOOS	Knee - specific patient-reported outcome that measures the patient's own assessment of knee problems and related problems. The schedule consists of 42 questions representing 5 strands.	Measured 8 week postoperatively
KOOS	Knee - specific patient-reported outcome that measures the patient's own assessment of knee problems and related problems. The schedule consists of 42 questions representing 5 strands.	Measured 12 months postoperatively
Pain	Visual Analogue Scale (VAS pain score)	Measured 8 week postoperatively
Pain	Visual Analogue Scale (VAS pain score)	Measured 12 months postoperatively
Serum leptin.	Leptin is a hormone produced in fat tissue.	Measured 8 week postoperatively
Serum leptin.	Leptin is a hormone produced in fat tissue.	Measured 12 months postoperatively
Heart rate	Cardiovascular complications.	Measured 8 week postoperatively
Heart rate	Cardiovascular complications.	Measured 12 months postoperatively
Blood pressure	Cardiovascular complications.	Measured 8 week postoperatively
Blood pressure	Cardiovascular complications.	Measured 12 months postoperatively

Collaborators and Investigators

• Sponsor: University of Aarhus
• Collaborators: Cambridge Weight Plan Limited; The Danish Rheumatism Association
• Investigators: Principal Investigator: Kjeld Søballe, Prof. D.Msc, Department of Orthopedics Research Aarhus University Hospital

Study record dates

Study Major Dates

• Study Start: August 1, 2011
• Primary Completion (Actual): June 1, 2014
• Study Completion (Actual): June 1, 2014

Study Registration Dates

• First Submitted: September 7, 2011
• First Submitted That Met QC Criteria: November 7, 2011
• First Posted (Estimate): November 10, 2011

Study Record Updates

• Last Update Posted (Estimate): March 17, 2015
• Last Update Submitted That Met QC Criteria: March 16, 2015
• Last Verified: November 1, 2011

More Information

Terms related to this study

• Keywords: Obesity; Arthroplasty; Weight Loss; Osteoarthritis, knee
• Additional Relevant MeSH Terms: Body Weight; Joint Diseases; Musculoskeletal Diseases; Rheumatic Diseases; Arthritis; Body Weight Changes; Osteoarthritis; Osteoarthritis, Knee; Weight Loss
• Other Study ID Numbers: TKABMI