Correction of Angular Deformities in Knee Arthrosis
Research type
Research Study
Full title
Patient Matched Osteotomy to Correct Angular Deformities in Knee Arthrosis
IRAS ID
123744
Contact name
Justin P Cobb
Contact email
Sponsor organisation
Imperial College London
Duration of Study in the UK
2 years, 0 months, 1 days
Research summary
Research Summary
For people whose leg bones don’t line up properly, extra stress is placed on either the inner or outer side of the knee joint due to uneven transfer of body-weight. Gradually, this extra pressure wears away the smooth cartilage, resulting in osteoarthritis on that side of the knee joint. This problem is particularly common in young athletes, and places them at risk of early osteoarthritis.
An operation exists whereby one of the bones either side of the knee is cut (an osteotomy) and hinged open to straighten the leg. This alteration redistributes body-weight more equally across the knee joint, and is known to be effective in delaying, and possibly preventing, the progression of knee osteoarthritis - especially in younger and physically more active patients in whom a knee replacement is undesirable.
Currently, it is possible to (accurately) calculate the precise position of the bone cut, and number of degrees correction required to straighten a leg, using digital X-rays and three- dimensional CT scans. However there is no method of implementing this pre-operative plan during surgery, so that the the majority of surgeons rely on relatively crude and ipso facto unreliable intra-operative measurements as a guide. It’s the equivalent of a builder trying to implement an architect’s detailed plan without a tape measure.
To improve the accuracy of this operation we propose the use of a custom-made ‘cutting block’, tailored for each individual patient. And it’s shape will match the contour of the patient’s bone to ensure it can only be placed in one position. Pre-cut slots and holes will then guide the saw cut and the number of degrees the bone is hinged open, as per the pre-operative plan; it functions as an intra-operative template for the surgeon.
This study will primarily examine whether there is a close match between the planned and actual correction of leg deformities when using a patient-matched cutting-block.
Summary of Results
This study demonstrates that a novel PSI for HTO can deliver a mean angular correction within 3 degree of the 3D preoperative plan. However, larger coronal plane corrections were associated with increasing under-correction, which needs to be addressed before widespread adoption of this technique can be recommended.
REC name
London - Stanmore Research Ethics Committee
REC reference
13/LO/1639
Date of REC Opinion
18 Nov 2013
REC opinion
Favourable Opinion