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Completed

NCT Number: NCT01469403

Weight Loss Intervention Before Total Knee Replacement

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.

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Key information

Conditions

Osteoarthritis, Knee Arthritis Body Weight Body Weight Changes Joint Diseases Musculoskeletal Diseases Nutrition Disorders Nutritional and Metabolic Diseases Obesity Osteoarthritis Overnutrition Overweight Pathological Conditions, Signs and Symptoms Rheumatic Diseases Signs and Symptoms Weight Loss

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Department of Orthopedics Research Aarhus University Hospital

Aarhus, 8000, Denmark

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

8 weeks weight loss program, Cambridge.

Behavioral

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.

Primary outcomes

  1. SF-36

    Time frame: Measured 12 months postoperatively.

    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.

Secondary outcomes

  1. 6 minutes walk test (6MW).

    Time frame: Measured 1 week before surgery.

    Used to target the operating level of the patient's daily activities.

  2. Body composition

    Time frame: Measured 1 week before surgery.

    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.

  3. Bone mineral density (BMD).

    Time frame: Measured 12 months postoperatively.

    Measured by DEXA scan.

  4. KOOS

    Time frame: Measured 1 week before surgery.

    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.

  5. Pain

    Time frame: Measured 1 week before surgery.

    Visual Analogue Scale (VAS pain score)

  6. Serum leptin.

    Time frame: Measured 1 week before surgery.

    Leptin is a hormone produced in fat tissue.

  7. Heart rate

    Time frame: Measured 1 week before surgery.

    Cardiovascular complications.

  8. Blood pressure

    Time frame: Measured 1 week before surgery.

    Cardiovascular complications.

  9. 6 minutes walk test (6MW).

    Time frame: Measured 8 week postoperatively.

    Used to target the operating level of the patient's daily activities.

  10. 6 minutes walk test (6MW).

    Time frame: Measured 12 months postoperatively

    Used to target the operating level of the patient's daily activities.

  11. Body composition

    Time frame: Measured 8 week postoperatively

    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.

  12. Body composition

    Time frame: Measured 12 months postoperatively

    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.

  13. KOOS

    Time frame: Measured 8 week postoperatively

    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.

  14. KOOS

    Time frame: Measured 12 months postoperatively

    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.

  15. Pain

    Time frame: Measured 8 week postoperatively

    Visual Analogue Scale (VAS pain score)

  16. Pain

    Time frame: Measured 12 months postoperatively

    Visual Analogue Scale (VAS pain score)

  17. Serum leptin.

    Time frame: Measured 8 week postoperatively

    Leptin is a hormone produced in fat tissue.

  18. Serum leptin.

    Time frame: Measured 12 months postoperatively

    Leptin is a hormone produced in fat tissue.

  19. Heart rate

    Time frame: Measured 8 week postoperatively

    Cardiovascular complications.

  20. Heart rate

    Time frame: Measured 12 months postoperatively

    Cardiovascular complications.

  21. Blood pressure

    Time frame: Measured 8 week postoperatively

    Cardiovascular complications.

  22. Blood pressure

    Time frame: Measured 12 months postoperatively

    Cardiovascular complications.

Sponsors and collaborators

Lead sponsor

University of Aarhus

Other

Collaborators

  • Cambridge Weight Plan Limited
  • The Danish Rheumatism Association

Registry information

Official study title

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

Important dates

Study start
2011
Primary completion
2014
Study completion
2014
First posted
Nov 10, 2011
Registry last updated
Mar 17, 2015

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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