Working…
ClinicalTrials.gov
ClinicalTrials.gov Menu

Validation of a Stress Device for the Knee

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
 
ClinicalTrials.gov Identifier: NCT02444663
Recruitment Status : Unknown
Verified May 2015 by Oxford University Hospitals NHS Trust.
Recruitment status was:  Not yet recruiting
First Posted : May 14, 2015
Last Update Posted : May 14, 2015
Sponsor:
Collaborator:
University of Oxford
Information provided by (Responsible Party):
Oxford University Hospitals NHS Trust

Brief Summary:

X-rays are the most frequently used imaging test when evaluating the knee for joint replacement. They are non-invasive, safe and cost effective. They allow assessment of: progression of disease, appropriateness for joint replacement (in particular unicompartmental knee replacement (UKR)) as well as likely prognosis following replacement.

Currently standard assessment involves: standing anteroposterior, lateral and skyline X-ray views. In addition in patients being considered for joint replacement valgus/varus stress X-rays are used to evaluate the lateral compartment (as well as medial collateral ligament) and medial compartment respectively to assess the status of the cartilage. Stress X-rays require the clinician to attend X-ray, often during busy clinics, exposing them to additional radiation, and as such they are seldom performed.

A patient and user friendly device for performing valgus and varus stress X-rays of the knee for diagnostic and pre-operative planning purposes in the setting of knee replacement surgery has been developed. This device has the potential to benefit patients as it will allow an accurate assessment of the pattern and severity of arthritis affecting their knee without the need for additional diagnostics such as MRI or arthroscopy. Furthermore for healthcare practitioners and providers this device will facilitate the smooth running of clinics and reduce the additional clinic appointments required to review MRI results. Ultimately this device will allow an informed discussion about treatment options, reduce the pre-operative uncertainty about suitability for UKR in those undergoing surgery and ensure that those patients who are suitable for UKR benefit from this procedure. This device will help ensure that patients receive the optimum treatment in a clinically and cost efficient manner.

This study will validate valgus and varus stress X-rays performed using the investigators' device against the gold standard of clinician performed manual stress.


Condition or disease Intervention/treatment Phase
Osteoarthritis, Knee Radiation: Clinician Valgus Radiation: Clinician Varus Radiation: Device Valgus Radiation: Device Varus Phase 4

Detailed Description:

X-rays are the most frequently used imaging test when evaluating the knee for joint replacement. They are non-invasive, safe and cost effective. They allow assessment of: progression of disease, appropriateness for joint replacement (in particular unicompartmental knee replacement (UKR)) as well as likely prognosis following replacement.

Currently standard assessment involves: standing anteroposterior, lateral and skyline X-ray views. In addition in patients being considered for joint replacement valgus/varus stress X-rays are used to evaluate the lateral compartment (as well as medial collateral ligament) and medial compartment respectively to assess the status of the cartilage.

The assessment of pattern and severity of disease is critical when evaluating suitability for joint replacement and well as when deciding between total knee replacement (TKR), where all articulating surface are replaced, or UKR, where only the diseased portion of the joint is replaced. Understanding the pattern of disease is essential to ensure appropriate patient selection for UKR, which is appropriate in up to half of patients undergoing knee replacement, and has significant benefits over TKR including: half the risk of venous thromboembolism, myocardial infarction or deep infection, two thirds the risk of stroke, one quarter the risk of blood transfusion and significantly lower mortality up to eight years following their operation.

Stress X-rays are currently performed by the clinician, requiring them to attend radiology, often during clinic. To perform the stress views the clinician fixes the knee and moves the tibia away from the midline, valgus stress, where an X-ray is taken. The alignment of this view is confirmed before the tibia is moved towards the midline, varus stress, where another X-ray is taken. Stress X-rays are resource dependent and can be time consuming. In addition, the technique can be uncomfortable for patients as well as resulting in additional radiation exposure to the clinical practitioner. On an average, a knee surgeon may be exposing themselves to excess of 300 exposures every year with the cumulative effect of radiation exposure being significant. As such in many centers stress views are often not performed, and as standing antero-posterior X-ray views are inadequate to assess disease severity and pattern many clinicians have adopted additional imaging modalities such as MRI or direct observation via arthroscopy to evaluate the status of the cartilage in each compartment. The use of these additional imaging techniques introduces significant additional costs as well as delays to treatment. Furthermore the long term outcomes of UKR have been established using stress views, and as a consequence outcomes based on MRI or arthroscopic findings have not been fully established.

A patient and user friendly device for performing valgus and varus stress X-rays of the knee for diagnostic and pre-operative planning purposes in the setting of knee replacement surgery has been developed. This device has the potential to benefit patients as it will allow an accurate assessment of the pattern and severity of arthritis affecting their knee without the need for additional diagnostics such as MRI or arthroscopy. Furthermore for healthcare practitioners and providers this device will facilitate the smooth running of clinics and reduce the additional clinic appointments required to review MRI results. Ultimately this device will allow an informed discussion about treatment options, reduce the pre-operative uncertainty about suitability for UKR in those undergoing surgery and ensure that those patients who are suitable for UKR benefit from this procedure. This device will help ensure that patients receive the optimum treatment in a clinically and cost efficient manner.

This study will validate valgus and varus stress X-rays performed using the investigators' device against the gold standard of clinician performed manual stress.


Layout table for study information
Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 60 participants
Allocation: Non-Randomized
Intervention Model: Crossover Assignment
Masking: Single (Outcomes Assessor)
Primary Purpose: Diagnostic
Official Title: Validation of a Device for Performing Valgus and Varus Stress X-rays of the Knee
Study Start Date : July 2015
Estimated Primary Completion Date : December 2016
Estimated Study Completion Date : December 2016

Resource links provided by the National Library of Medicine

MedlinePlus related topics: X-Rays

Arm Intervention/treatment
Active Comparator: Clinician Valgus
Clinician performed fluoroscopic valgus and varus stress X-rays
Radiation: Clinician Valgus
Clinician performed valgus stress X-ray under fluoroscopy

Active Comparator: Clinician Varus
Clinician performed fluoroscopic varus stress X-rays
Radiation: Clinician Varus
Clinician performed varus stress X-ray under fluoroscopy

Experimental: Device Valgus
Device performed fluoroscopic valgus stress X-rays
Radiation: Device Valgus
Device (Oxford Stress System for Knee Arthroplasty Radiographs (OSSKAR)) performed valgus stress X-ray under fluoroscopy.

Experimental: Device Varus
Device performed fluoroscopic varus stress X-rays
Radiation: Device Varus
Device (Oxford Stress System for Knee Arthroplasty Radiographs (OSSKAR)) performed varus stress X-ray under fluoroscopy.




Primary Outcome Measures :
  1. Knee minimum joint space width (medial and lateral compartment) [ Time Frame: Day 0 ]
    Knee minimum joint space width (medial and lateral compartment) measured on anteroposterior fluoroscopic images using custom, validated, in house software (KneeMorph, MATLAB, MathWorks, Massachusetts).


Secondary Outcome Measures :
  1. Force (N) required [ Time Frame: At time of procedure ]
    Force (N) required to result in minimum joint space width measured on anteroposterior fluoroscopic images using custom, validated, in house software (KneeMorph, MATLAB, MathWorks, Massachusetts) in the lateral compartment (valgus stress) and medial compartment (varus stress).



Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.


Layout table for eligibility information
Ages Eligible for Study:   50 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Participant is willing and able to give informed consent for participation in the study.
  • Male or Female, aged 50 years or above.
  • Knee osteoarthritis any grade, affecting the tibio-femoral joint
  • In the Investigator's opinion, is able and willing to comply with all trial requirements.
  • Willing to allow his or her General Practitioner and consultant, if appropriate, to be notified of participation in the trial.

Exclusion Criteria:

  • Previous joint replacement on ipsilateral knee
  • Previous anterior cruciate ligament reconstruction or injury
  • Previous high tibial osteotomy
  • Previous intra-articular fracture
  • History of Inflammatory arthritis

Additional Information:
Layout table for additonal information
Responsible Party: Oxford University Hospitals NHS Trust
ClinicalTrials.gov Identifier: NCT02444663     History of Changes
Other Study ID Numbers: 109367
First Posted: May 14, 2015    Key Record Dates
Last Update Posted: May 14, 2015
Last Verified: May 2015
Additional relevant MeSH terms:
Layout table for MeSH terms
Osteoarthritis, Knee
Osteoarthritis
Arthritis
Joint Diseases
Musculoskeletal Diseases
Rheumatic Diseases