Using in-shoe plantar pressure measurements to optimize inlays at patients with rheumatoid arthritis and footcomplaints: pilotstudy

Foot complaints are common in patients with arthritis. Approximately 90% of
patients with rheumatoid arthritis (RA) develop painfull feet or ankles during
the course of their disease. Data collected in a large RA cohort at Reade
showed that approximately 70% of adult patients had inflammation in one or more
joints of the forefoot at disease onset. After (drug) treatment this rate
dropped to 40%. The percentage of patients with joint damage on radiographs in
forefoot joints increased of approximately 20% at disease onset to 60% after 8
years of disease duration. Foot complaints lead to pain in activities, such as
standing, walking and climbing the stairs. Approximately 40% of the patients
experienced walking problems during the first 8 years of the disease.
Treatment of foot complaints consist of surgical intervention, treatment with
medication, and/or conservative treatment. Conservative treatment includes
inlays which are worn in the shoes. The inlays are made by a podiatrist, on
referral from a rehabilitation physician or rheumatologist. The purpose of
these inlays is reduction of the pressure under the feet, since high plantar
foot pressure is associated with joint damage and pain. Determining high
plantar foot pressure happens mostly through inspection and making a blueprint.
Research of Guldemond et al in patients with forefoot complaints shows that
this method leads to high variability in locating high plantar foot pressure
and is unreliable. The recommendation of this study is to perform plantar
pressure measurements in the shoe to locate high plantar pressure correctly.
Clinical practice also shows that the current approach is not optimal; patients
with RA often have to return several times to the podiatrist because the inlays
have not the desired effect on pain reduction.
For this study insole plantar pressure measurements will be used as a
diagnostic tool for optimizing inlays. If insole plantar pressure measurements
with inlays demonstrates that the plantar pressure has changed insufficiently,
the inlays will be adjusted. Multiple rounds of insole plantar pressure
measurements and inlay adjustments can take place to optimize the inlays. We
expect that this method of insole plantar pressure measurements and inlays
adjustments will lead to optimal inlays after one treatment session and
therefore to faster and more pain reduction than usual care. A similar method
of inlay adjustments based on insole plantar pressure measurements is already
applied in patients with diabetes mellitus (Bus et al). In patients with
diabetes mellitus insole plantar pressure measurements have been used to
optimize orthopedic shoes to prevent recurrent ulcerations.

Guldemond, N. A., Leffers, P., Nieman, F. H., Sanders, A. P., Schaper, N. C.,
and Walenkamp, G. H.Testing the proficiency to distinguish locations with
elevated plantar pressure within and between professional groups of foot
therapists.2006;7:93-

Bus, S. A., Haspels, R., and Busch-Westbroek, T. E.Evaluation and optimization
of therapeutic footwear for neuropathic diabetic foot patients using in-shoe
plantar pressure analysis.2011;34:1595-1600.

Goal of this project is to evaluate an innovative protocol for optimizing
inlays based on insole plantar pressure measurements in patients with RA. The
protocol will be evaluated on the following aspects: (i) the process of
optimizing inlays based on insole plantair pressure measurements (feasibility)
and (ii) the result of the inlays on plantar foot pressure, pain and physical
functioning.

This study will be performed as a pilot study. Forty RA patients will be
treated according to the innovative protocol. The treatment will be carried out
in a treatment session and a control session after 2 months. The treatment
session consists of a diagnostic phase and an intervention phase. During the
intervention phase inlays will be made and, if necessary, optimized through
multiple rounds of insole plantar pressure measurements and inlay-adjustments,
with a maximum of 3 rounds.
In the control session insole plantar pressure measurements will be repeated.
If necesarry, the insoles will be adjusted in the context of usual podiatry
care.

The podiatry treatment of this project is equal to usual podiatric care in
Reade. The burden for patients is minimized wherever possible and differs on
some points from usual podiatric care.

Additional burden for the patient:
-the intake will be up to 45 minutes longer because of extra insole plantar
pressure measurments and possible insole adjustments.
-At the end of the treatment an interview will take place with 10 of the 40
participating patients. This interview will take place adjacent to the
appoinment with the podiatrist and wil take a maximum of 45 minutes.
- At the end of the treatment a comprehensive satisfaction questionnaire will
be assessed in all patients.

Advantages for the patient:
-Treatment according to the innovative protocol is expected to be more time
efficient and more effective. We expect that the patient is provided with
optimal inlays after the first treatment session.

Risk
Since the podiatry treatment of this project is equal to usual podiatric care,
there are no additional risks related to this study.