Oral session 6: Biomechanics and offloading

Oral session 6: Biomechanics and offloading
O6.1
Do diabetic foot ulcers affect daily activity, energy expenditure and sleep?
Helen Sheahan, Queensland Health, Brisbane, Australia
Kimberley Canning, Queensland Health, Brisbane, Australia
Nishka Refausse, Queensland Health, Brisbane, Australia
Ewan Kinnear, Queensland Health, Brisbane, Australia
Betty Mulder, Queensland Health, Brisbane, Australia
Greg Jorgensen, Queensland Health, Brisbane, Australia
James Walsh, Queensland Health, Brisbane, Australia
Peter Lazzarini, Queensland University of Technology, Brisbane, Australia
Aim: Very few studies have investigated daily activity, energy expenditure and sleep in
people with active diabetic foot ulcers (DFU)., The aim of this case-control study was to
investigate daily activity, energy expenditure and sleep in people with DFU compared to
those with diabetes and no history of DFU.
Methods: Participants with type 2 diabetes were recruited into three groups: i) current
neuropathic foot ulcers (DFU), ii) peripheral neuropathy without DFU history (DPN), iii) nil
peripheral neuropathy or DFU history (DNIL)., Exclusion criteria included peripheral arterial
disease and mobility aid use., Participants wore a multi-sensor SenseWear Pro 3 Armband
device continuously for 7 days and completed an Epworth Sleepiness Scale., The Armband
is a validated automated measure of free-living daily activity (steps, Metabolic Equivalent
Tasks (MET), physical activity (>3 METs) duration), energy expenditure(kJ) (total and
physical activity (>3 METs)) and sleep (duration)., Data on age, sex, BMI, diabetes duration
and HbA1c were also collected.
Results: Sixty-six (30 DFU, 22 DPN and 14 DNIL) participants were recruited; mean±SD
age 61±12 years, 71% males, BMI 32.6±5.9, diabetes duration 13±9 years, HbA1c 8.4±4.2,
and average METs 1.2±0.2., No significant demographic differences were reported between
groups (p > 0.2); except for mean age (57±11 DFU, 68±9 DPN; 58±11 NIL; p = 0.001).,
Mean steps per day was different between groups: 3 271±2 417 DFU, 5 007±3 349 DPN and
5 859±2 381 DNIL (p = 0.01)., Mean daily energy expenditure (kJ) was also different
between groups: 13 006± 3 559 DFU, 11 060±1 916 DPN and 10 868±1 307 DNIL (p <
0.02)., No significant differences were reported between groups for average METs, physical
activity duration or energy expenditure, sleep time or Epworth score (p > 0.2).
Conclusions: Findings indicate people with diabetes and active foot ulcers walk much less,
but expend much more energy in doing so than those people with diabetes and no foot ulcer
history., Sleep and physical activity parameters showed no differences., Further research is
required to investigate safe “activity dosing” and balancing of daily energy demands to
optimise wound healing in people with DFU.
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O6.2
Gait and perceived comfort implications of offloading devices’: size and induced limb
length inequality
Ryan Crews, Rosalind Franklin University, North Chicago, IL, United States
Joseph Candela, Rosalind Franklin University, North Chicago, IL, United States
Ghazizadeh Ramin, Rosalind Franklin University, North Chicago, IL, United States
Aim: Removable cast walkers (RCW) help heal diabetic foot ulcers (DFU) by offloading the
injured foot during weight bearing activities. However, patients’ RCW compliance is often
poor. RCW designs give little consideration to the impeded gait or postural instability they
induce. This study evaluated how 1) using an elevating device (lift) on the contralateral foot
and 2) modifying RCW size, would impact detrimental changes in gait and comfort
associated with RCW.
Methods: Twenty-five adults at risk for DFU were recruited. Subjects walked a 20m walkway
in five different conditions: control (bilateral athletic shoes), short RCW with and without
contralateral lift, tall RCW with and without contralateral lift. A 7.3m GaitRite mat recorded
spatial and temporal parameters of steps and Pedar-X pressure insoles recorded bilateral
pressure data. Subjects rated the comfort of each footwear condition with a 12cm visual
analog scale.
Results: In comparison to the control condition, the short RCW had a significantly smaller
reduction in velocity than the tall RCW (9.5 ±2.8% vs. 15.1±3.0%). The lift did not
significantly alter gait velocity. Plantar pressure data indicated the offloaded foot was best
offloaded in the tall RCW and no-lift conditions. Conversely, the contralateral foot saw the
least pressure in the short RCW and lift conditions. The varied footwear conditions yielded
significantly (p<.05) different comfort ratings (Figure 1).
Conclusions: The most comfortable footwear condition was the short RCW plus
contralateral foot lift. It remains unknown whether the reduced loading of the contralateral
foot and improved patient comfort (which may lead to improved RCW compliance) observed
in that footwear condition, outweigh the drawback of reduced offloading of the RCW foot.
Mean comfort rating for each
condition is presented with error
bars representing standard
deviation values. Each star above
a footwear condition indicates a
successively lower mean value
compared to other conditions
(p<.05). sRCW= short RCW;
tRCW= tall RCW
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O6.3
Total contact cast treatment for the diabetic foot; with or without antithrombotic
prophylaxis?
I.M. Reeder, University Hospital Maastricht, Maastricht, Netherlands
R. Sleegers, University Hospital Maastricht, Maastricht, Netherlands
M.A. Witlox, University Hospital Maastricht, Maastricht, Netherlands
N.C. Schaper, University Hospital Maastricht, Maastricht, Netherlands
J.P.S. Hermus, Department of Orthopaedic surgery, Maastricht University Medical Centre,
Maastricht, Maastricht, Netherlands
Aim: Below knee immobilisation with a cast is according to several studies associated with
deep venous thrombosis (DVT), incidence rates up to 19% have been reported1.
International guidelines provide contradictory advice about the use of low molecular weight
heparin (LMWH) in patients treated with casts2. A total contact cast (TCC) is frequently used
in diabetic patients for non-traumatic complications and may result in an increased DVT risk.,
In our clinic LMWH is not prescribed. Therefore, the aim of this study was to determine the
incidence of DVT or other thromboembolic events in diabetic patients treated with a TCC
without any antithrombotic therapy.
Methods: All patients treated for at least 2 weeks at our outpatient clinic by our
multidisciplinary foot-team with a below knee TCC, for a diabetic foot ulcer and/or an acute
Charcot, between May 1997 and August 2014 were eligible for inclusion in this retrospective
study. Patients with antithrombotic therapy were excluded. The development of a DVT,
defined according to international criteria (including echo) or a thromboembolic event during
TCC treatment and during 2 months follow-up was objectified using the electronic patient file
of the hospital. In case of missing data the general practitioner and/or the patient was
contacted.
Results: A total of 101 patients (mean age 59 year, 64 male) were analysed. The majority,
73 patients, were treated for more than 6 weeks with a TCC. The total number of
persondays of TCC treatment was 10.984, with a median duration of 84 days (interquartile
ranges 42-161). Per patient 2.15 episodes of TCC treatment was given of which 0.39 for
Charcot, 1.08 for a foot ulcer and 0.68 for the combination of both. No patient experienced a
thromboembolic event during treatment or during follow-up.
Conclusion: During a total at risk exposure of more than 10.000 TCC days and during 2
months follow-up, no patient experienced a thromboembolic event. The absence of a DVT or
other thromboembolic event in diabetic patients treated with TCC suggests that nontraumatic lower limb immobilisation with a TCC is in these patients not an indication for
antithrombotic prophylaxis.
1.M.R. Lassen et al. N Engl J Med 2002 Sep 5;347(10):726-30.
2.M.C. Struijk-Mulder et al. J Thromb Haemost 2010;8:678–83.
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O6.4
Can’t Stand The Pressure: The association between unprotected standing, walking
and wound healing
Bijan Najafi, University of Arizona, College of Medicine, Tucson, AZ, United States
Gurtej Grewal, University of Arizona, College of Medicine, Tucson, AZ, United States
Manish Bharara, University of Arizona, College of Medicine, Tucson, AZ, United States
Robert Menzies, Hamad Medical Co, Doha, Qatar
K. Talal, Hamad Medical Co, Doha, Qatar
David Armstrong, University of Arizona, College of Medicine, Tucson, AZ, United States
Aims: To report patterns of physical activity and their relationship to wound healing success
in patients with diabetic foot ulcers protected with removable or irremovable offloading
devices.
Methods: Forty-nine patients with plantar neuropathic foot ulcers were randomized to wear
either a removable cast walker (RCW) or an irremovable instant total contact cast (iTCC).
Primary outcome measures included change in wound size, organization and magnitude of
daily activity including position (i.e. sitting, standing, lying) and locomotion (speed, steps,
etc.). Outcomes parameters were assessed on weekly basis until wound healing or till 12
weeks.
Results: Proportion of healing at 12 weeks was higher in the iTCC, group (p=0.04).
Significant differences in activity were observed between groups starting at week 4. RCW
patients became more active (75% higher duration of standing, 100% longer duration of
walking, and 126% longer continuous walking episode compared to iTCC group (p<0.05 for
all). Overall, there was an inverse association between rate of weekly wound healing and
number of steps taken per day (r<-0.33, p<0.05) for both groups. However, the RCW group
had an even more profound correlation between duration of daily standing and weekly rate
of healing (r=-0.67, p<0.05). The duration of standing was the only significant predictor for
the success of wound healing at 12 weeks.
Conclusion: The results from this study suggest significant and fascinating differences in
activity patterns between removable and irremovable offloading devices. These patterns
appear to start diverging at week 4, which may indicate decline in adherence to offloading.
Results suggest that while walking may delay wound healing, unprotected standing might be
an even more silent, sinister culprit.
Support: Qatar National Research Foundation, NPRP 4-1026-3-277
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O6.5
Development of foot ulcers and amputations in type 2 diabetes mellitus patients
without therapeutic footwear: a retrospective claims study
Michael Minshall, DJO Global, Vista, CA, United States
Emily Durden, Truven Health Analytics, Ann Arbor, MI, United States
Donna McMorrow, Truven Health Analytics, Ann Arbor, MI, United States
Roy Lidtke, Rush University Medical Center, Chicago, IL, United States
Aims: Study purpose was to describe the primary and secondary development of foot ulcers
and lower limb amputations in Type 2 Diabetes mellitus (T2DM) patients, without therapeutic
footwear, using claims data over a 2-year period.
Methods: Inclusion criterion were:1) ≥3 years (1 year before as pre-index, 2 years after a
randomly assigned index date) of continuous medical and pharmacy enrollment in a health
plan; 2) ≥1 inpatient and/or non-diagnostic outpatient medical claim with a T2DM diagnosis
(ICD-9-CM 250.x0 or 250.x2) in the pre-index period; 3) aged >18 years; 4) without or
evidence of foot ulcer for the primary (n=21 465) and secondary progression (n=4 792)
groups, respectively. Included patients were propensity-score matched to an equal number
of T2DM patients with therapeutic footwear claim(s) in order to assess untreated diabetic
foot disease. Patients were excluded if they had any claims for therapeutic footwear.
Comorbidity and T2DM complication characteristics at baseline and 2 years of follow up are
described in Table 1.
Results: The primary progression group demonstrated a 5.1% rate of foot ulcers at 2 years
while the secondary progression group showed a 42.3% rate of additional foot ulcers at 2
years. The primary progression group demonstrated a 0.4% rate of lower limb amputations
at 2 years while the secondary progression group showed a 6.3% rate of additional lower
limb amputations at 2 years. Each population demonstrated increases over the 2-year study
period in claims for both T2DM comorbidities and complications.
Conclusions: The rapid development of foot ulcers and amputations in the primary and
secondary progression groups highlight an important opportunity for public health
interventions targeted towards foot ulcer and amputation prevention.
Primary
Primary
Secondary Secondary
T2DM Comorbidities
Baseline
2-Years
Baseline
2-Years
Cardiovascular Conditions
52.2%
75.5%
67.4%
95.3%
Depression
7.1%
12.0%
8.7%
15.8%
Hypertension
63.7%
79.8%
71.0%
83.1%
Kidney Disease
11.5%
17.6%
19.7%
27.7%
Obesity
5.8%
10.5%
10.1%
16.3%
Selected T2DM Complications
Foot Ulceration
0%*
5.1%**
100%*
42.3%**
Polyneuropathy
3.0%
4.5%
9.7%
13.3%
Amputations of the lower limb
0.1%
0.4%
8.4%
6.3%*
Atherosclerosis
13.2%
15.8%
29.8%
32.4%
Diabetic retinopathy
10.5%
13.4%
19.5%
23.9%
Diabetic nephropathy
6.5%
9.9%
11.9%
17.8%
*Primary and secondary populations were selected for 0% and 100% foot ulcers at baseline,
respectively.
**Depicts additional foot ulcers and lower limb amputations after baseline.
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