TT-TG distance in different positions of the leg
Research type
Research Study
Full title
Variation of the TT-TG distance in different positions of the leg as measured by MRI.
IRAS ID
180880
Contact name
Mary Jones
Contact email
Sponsor organisation
Fortius Clinic
Duration of Study in the UK
0 years, 4 months, 1 days
Research summary
Instability of the patella (kneecap) is a common painful and disabling condition which can be caused by an abnormality in the shape of the bones of the patellofemoral joint. The trochlear groove, which the patella sits in as the knee moves, can be measured on MRI scans. These measurements are known as the TT-TG distance
It is essential that these measurements are accurate and reliable as they are used to aid diagnosis and plan the surgical procedure required to stabilise the patella. The CI has noticed that the TT-TG distance can vary according to the position of the patient’s leg which could lead to inaccuracies in diagnosis and surgery. However there is no evidence available to show if this is really the case.
This research study proposes measuring the TT-TG distance on MRI and comparing the difference in these measurements when the scan is performed with the leg internally rotated (turned in) compared to the leg being externally rotated (turned out). We will also determine if different clinicians measure it in the same way.
The study will be carried out on both healthy volunteers to measure the TT-TG distance in normal knees and patients to measure the TT-TG distance in abnormal knees. Patients will only be asked to take part in the study if they would already be receiving an MRI as part of their routine care. Taking part in the study would mean that their scan would take longer than usual.
If the study shows that the leg position does alter the TT-TG distance the protocol for taking these MRI scans would be changed to ensure that the scan is always performed with the leg in the same position. This would make the measurements more accurate and could prevent inappropriate treatment.REC name
North East - York Research Ethics Committee
REC reference
15/NE/0289
Date of REC Opinion
14 Aug 2015
REC opinion
Favourable Opinion