There is increasing evidence that flexible flatfoot (FF) can
lead to symptoms and impairment in health-related quality of life.
As such we undertook an observational study investigating the aetiology
of this condition, to help inform management. The hypothesis was
that as well as increased body mass index (BMI) and increased flexibility of
the lower limb, an absent anterior subtalar articulation would be
associated with a flatter foot posture. A total of 84 children aged between eight and 15 years old were
prospectively recruited. The BMI for each child was calculated,
flexibility was assessed using the lower limb assessment scale (LLAS)
and foot posture was quantified using the arch height index (AHI).
Each child underwent a sagittal T1-weighted MRI scan of at least
one foot. Aims
Patients and Methods
The Oxford medial unicompartmental knee replacement was designed to reproduce normal mobility and forces in the knee, but its detailed effect on the patellofemoral joint has not been studied previously. We have examined the effect on patellofemoral mechanics of the knee by simultaneously measuring patellofemoral kinematics and forces in 11 cadaver knee specimens in a supine leg-extension rig. Comparison was made between the intact normal knee and sequential unicompartmental and total knee replacement. Following medial mobile-bearing unicompartmental replacement in 11 knees, patellofemoral kinematics and forces did not change significantly from those in the intact knee across any measured parameter. In contrast, following posterior cruciate ligament retaining total knee replacement in eight knees, there were significant changes in patellofemoral movement and forces. The Oxford device appears to produce near-normal patellofemoral mechanics, which may partly explain the low incidence of complications with the extensor mechanism associated with clinical use.
