Hindfoot alignment in TKR
Research type
Research Study
Full title
Hindfoot alignment in TKR- validation of a novel radiographic study
IRAS ID
183285
Contact name
Catherine Sinclair
Contact email
Sponsor organisation
Research and Development Manager, Golden Jubilee National Hospital
Duration of Study in the UK
0 years, 4 months, 0 days
Research summary
When carrying out a knee replacement operation one of the goals is to correct any deformity of the leg (bow-legged or knock-kneed). The ideal alignment is the mechanical axis, which is a line from the centre of the hip joint to the centre of the ankle. This line indicates the how the weight of the body is transmitted to the ground via the leg. Often the planning for a knee replacement uses an X-ray which shows the hip, knee and ankle (HKA X-ray) so that the mechanical axis can be drawn on.
However, the weight of the body goes to the ground from the ankle through the heel. There have been some reports recently suggesting that deformities in the heel can influence the overall leg alignment after a knee replacement; this may affect how successful the surgery is, or how long the knee replacement will last. Therefore it may make sense to take the alignment of the leg including the heel in planning for a knee replacement.
The conventional practice to assess the alignment of the heel is a hindfoot alignment view (HAV) X-ray. This only shows the foot. Having two separate X-rays makes linking the two alignments very difficult and means more radiation exposure for the patient. We propose a single novel X-ray extending the HKA X-ray to shows hip, knee, ankle and hindfoot (HKAH X-ray) enabling measurement of both alignments.
This study is to validate the hindfoot alignment seen on the novel X-ray with the standard HAV. Patients undergoing a knee replacement will be enrolled. Patients will have both a HKAH and HAV X-ray before surgery instead of a HKA X-ray. The alignment of the heel measured on the HKAH X-ray will be compared with the standard HAV to see if it is accurate.REC name
West of Scotland REC 5
REC reference
15/WS/0267
Date of REC Opinion
24 Nov 2015
REC opinion
Favourable Opinion