CClinicalTrials.gg
CompletedNCT05137834Updated Jul 16, 2025

The Effect of Postoperative "Peanut Ball" Rehabilitation After Total Knee Replacement.

An interventional study of Exercise in Knee Osteoarthritis, sponsored by Region Skane. Completed at 1 site in Sweden. Open to participants aged 18 Years to 90 Years. Per ClinicalTrials.gov, last updated 2025-07-16.

Sponsored by Region Skane · Not applicable, Interventional, and Treatment

From the registry’s dates

  • Registered 10 months after the study started (first participant enrolled Jan 2021, registered Nov 2021).
Phase
Not applicable
Study type
Interventional
Enrollment
300
Allocation
Randomized
Ages
18 Years to 90 Years
Sex
All
01

Study summary

The purpose of this randomized controlled study is to evaluate the effect of postoperative exercise with a "peanut ball" after total knee replacement, on pain, intake of pain killers, knee function, and health-related quality of life.

Read the detailed description

After being informed about the study and potential risks, all patients giving written informed consent will be included in the study.

At baseline, before surgery, all patients will meet a nurse, a physical therapist, and an orthopedic doctor and answer questions about their health condition and do functional tests.

Each week is randomized to be either "peanut ball" or standard exercise week, with all patients during that week receiving the same treatment. Thus, depending on what week the patients are operated they will be mobilized with postoperative exercise with a "peanut ball" or to a standard exercise program (no peanut ball) 3-5 times/day for 6 weeks. All patients randomized to exercise with a "peanut ball" will receive a ball for free to bring home.

At the ward, the nurses will ask about the patient's pain level two times a day and register all medicines. The physical therapist will introduce the exercise and inform the patients to do the exercise 3-5 times/day a´ 15 minutes and fill in all exercises in an exercise diary.

2 weeks after surgery all patients have a standard visit to a nurse and a physical therapist at the orthopedic department. At this visit, the nurse will register the pain level and all intake of medicine and the physical therapist will measure the range of movement and the sit to stand test.

3 months after surgery all patients have a standard visit to a physical therapist at the orthopedic department. At this visit, all outcomes will be filled in or measured.

02

Conditions studied

  • Knee Osteoarthritis
03

In context

Osteoarthritis, Knee

3,302 studies on the registry are indexed under Osteoarthritis, Knee; 608 are open to participants now.

This study's enrollment of 300 is above the median of 70 across 2,731 interventional studies indexed under Osteoarthritis, Knee.

Browse Osteoarthritis, Knee studies →

Lead sponsor

Region Skane is the lead sponsor of 372 studies on the registry; 113 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 90 Years
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  • Patients with osteoarthritis planned for surgery with total knee replacement at Skåne University Hospital.

Exclusion criteria

Exclusion Criteria:

  • Patients who do not understand and talk the Swedish language
  • Patients with dementia
  • Revision surgery of the knee
  • Unicompartmentmental knee replacement
05

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
300 participants (actual)

Study arms

  • Experimental
    Exercise with a "peanut ball".

    The rehabilitation program consists of mobility- and functional training exercises with a "peanut ball".

    Other: Exercise

  • Active comparator
    Exercise without "peanut ball"

    The rehabilitation program consists of standard mobility- and functional training exercises without a "peanut ball".

    Other: Exercise

Interventions

  • OtherExercise

    Post-surgical exercise

06

What researchers measure

Primary outcomes

  1. Visual analogue scale (VAS) (0-100)

    The scale is from 0-100 and a higher value is associated with more pain. 0:no pain and 100: most possible pain.

    Time frame: Change from baseline (before surgery) to 3 months after surgery

Secondary outcomes

  1. Range of movement

    The range of movement in the knee is measured with a goniometer. The range of movement may be between 0 degree to 145 degree. A higher degree is better.

    Time frame: Change from baseline (before surgery) to 3 months after surgery

  2. Forgotten Joint Score (FJS)

    Is a questionnaire of the patients awareness of their knee. Minimum score:0 (worse outcome), maximum score 100 (best outcome)

    Time frame: Change from baseline (before surgery) to 3 months after surgery.

  3. Knee injury and Osteoarthritis Outcome Score (KOOS-12)

    Is a questionnaire of knee related function an quality of life. It consists of three parts: pain (4 items), function (4 items) and knee-specific quality of life (4 items). KOOS-12; in pain sub-item; In the sub-item of walking on a flat ground, going up and down stairs, sitting-reaching, function and daily life; There are patient-specific questions in the sub-item of quality of life, sitting up, standing, getting in and out of the car, turning the affected knee. The total scores obtained from the items in the KOOS-12 scale are calculated and the average of the total score is taken from the three sub-dimensions. If any of the three sub-item scores are missing, the average score cannot be calculated.

    Time frame: Change from baseline (before surgery) to 3 months after surgery.

  4. 30 second sit to stand test

    A test to evaluate leg strength and endurance. The 30 second stair stand asks participants to rise and sit back down in a chair as many times as they can during that time period, without using hands or arms for support. Higher scores mean better outcome (e.g. more stands in 30 seconds).

    Time frame: Change from baseline (before surgery) to 3 months after surgery.

  5. Euro Qol-five dimensions, Visual analogue scale (EQ-5D VAS)

    Is a generic questionnaire about health related quality of life, 0-100, 0: The worst health you can imagine", 100: "the best health you can imagine". Patients are asked to indicate how your health is today and to write the number in an adoining box.

    Time frame: Change from baseline (before surgery) to 3 months after surgery.

07

Study locations

1 site
  • Region Skane, VO ortopedi
    Lund, Sweden
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Jul 16, 2025, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT05137834
Lead sponsor
Region Skane
Responsible party
Sponsor
First posted
Nov 30, 2021
Start date
Jan 10, 2021
Primary completion
Dec 30, 2023
Completion
Dec 30, 2024
Last update
Jul 16, 2025

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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This study is completed, as verified in Jul 2025. You cannot join it, but the record below documents what was studied.

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