Plantar Fat-Pad Displacement in Neuropathic Diabetic Patients With Toe Deformity
A magnetic resonance imaging study
- Sicco A. Bus, MSC1,
- Mario Maas, MD, PHD2,
- Peter R. Cavanagh, PHD, DSC3,
- Robert P. J. Michels, MD, PHD1 and
- Marcel Levi, MD, PHD1
- 1Department of Internal Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
- 2Department of Radiology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
- 3Department of Biomedical Engineering, Lerner Research Institute, The Cleveland Clinic Foundation, Cleveland, Ohio
- Address correspondence and reprint requests to Sicco A. Bus, MSc, Department of Internal Medicine, Room F4-252, Academic Medical Center, University of Amsterdam, P.O. Box 22700, 1100 DE Amsterdam, Netherlands. E-mail: s.a.bus{at}amc.uva.nl
Abstract
OBJECTIVE—The aim of this study was to quantify the association between claw/hammer toe deformity and changes in submetatarsal head (sub-MTH) fat-pad geometry in diabetic neuropathic feet.
RESEARCH DESIGN AND METHODS—Thirteen neuropathic diabetic subjects (mean age 56.2 years) with toe deformity, 13 age- and sex-matched neuropathic diabetic control subjects without deformity, and 13 age- and sex-matched healthy control subjects without deformity were examined. From high-resolution sagittal plane magnetic resonance images of the second and third ray of the foot, toe angle (a measure of deformity), sub-MTH fat-pad thickness, and subphalangeal fat-pad thickness were measured. The ratio of these thicknesses was used to indicate fat-pad displacement.
RESULTS—Sub-MTH fat pads were significantly thinner (2.5 ± 1.3 vs. 6.0 ± 1.4 mm, P < 0.001) and subphalangeal fat pads significantly thicker (9.1 ± 1.9 vs. 7.6 ± 1.2 mm, P < 0.005) in the neuropathic group with deformity compared with neuropathic control subjects. As a result, thickness ratio was substantially smaller in the deformity group: 0.28 ± 0.14 vs. 0.79 ± 0.14 in neuropathic control subjects (P < 0.001). A significant correlation of 0.85 was present between toe angle and thickness ratio (P < 0.001). No significant differences were found between neuropathic and healthy control subjects.
CONCLUSIONS—This study shows a distal displacement and subsequent thinning of the sub-MTH fat pads in neuropathic diabetic patients with toe deformity and suggests that, as a result, the capacity of the tissue in this region to reduce focal plantar pressure is severely compromised. This condition is likely to increase the risk of plantar ulceration in these patients.
- MRI, magnetic resonance imaging
- MTH, metatarsal head
- MTP, metatarsal-phalangeal
- VPT, vibration perception threshold
Footnotes
-
A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.
-
- Accepted June 25, 2004.
- Received March 23, 2004.
- DIABETES CARE
