Metatarsal Phalangeal Joint Deformity Progression - R01
Condition: Diabetes Mellitus
MeSH terms: Congenital Abnormalities
Study type: Interventional

Summary: 
      The purpose of this research study is to determine the relationships between foot muscle,
      foot motion, and toe deformity. Results from this investigation will help the investigators
      to understand what contributes to foot deformities and the role of the foot muscles in the
      development of foot deformities. This could potentially guide treatment options focusing on
      strengthening the foot muscles to prevent or reduce the risk of developing a foot deformity.
    

Detailed description: 
      The long term goal of this research is to reduce the incidence of lower extremity amputation
      in people with diabetes mellitus and peripheral neuropathy. It is hypothesized that muscle,
      joint, and movement deterioration associated with diabetes and peripheral neuropathy
      contribute to metatarsophalangeal joint (MTPJ) hyperextension deformity. MTPJ deformity
      results in excessive plantar stress on the insensitive forefoot, leading to ulceration and
      amputation. However, the specific cause of MTPJ deformity is not clear. The overall goal of
      this proposal is to identify the causes of MTPJ deformity and examine the ability of a
      targeted foot specific intervention to de-couple diabetes related mechanisms from MTPJ
      deformity and progression, following participants for 3 years. The investigators hypothesize
      that the cause of MTPJ deformity is an interaction of the accumulation of advanced glycation
      end products, muscle deterioration, limited joint mobility and compensatory movement
      strategies.

      The specific aims are to determine:

        1. relationships between advanced glycation end products, intrinsic foot muscle volume,
           limited ankle dorsiflexion joint mobility, MTPJ hyperextension movement pattern, and
           MTPJ alignment;

        2. estimate the effect of a foot specific intervention on the MTPJ extension alignment and

        3. determine progression of MTPJ deformity and the predictors of progression over three
           years.

      The following will be collected on participants with diabetes mellitus and peripheral
      neuropathy and monitored over three years to understand the causes and progression of MTPJ
      deformity:

        1. Skin intrinsic florescence to measure advanced glycation end product accumulation which
           increases collagen cross-linking and is associated with peripheral neuropathy, limited
           joint mobility, and muscle deterioration.

        2. Magnetic resonance images to measure intrinsic foot muscle deterioration that precedes
           extrinsic foot muscle deterioration as a result of distal to proximal peripheral
           neuropathy. The muscle imbalance of weak intrinsic foot muscles, the only muscles able
           to flex the MTPJ, in the presence of relatively stronger extrinsic toe extensors,
           results in a force couple that hyperextends the MTPJ.

        3. Kinematic and computed tomography measurement of foot and ankle joint positions to
           examine mobility and movement patterns that contribute to repeated and extreme MTPJ
           hyperextension during daily activities.

      The investigators believe advanced glycation end products lead to limited ankle joint
      dorsiflexion. As a result, there is increased reliance on the extensor digitorum longus to
      assist in dorsiflexing the stiff ankle joint during activities like sit to stand. This study
      will have profound implications for reducing risk for skin breakdown and amputation by
      helping to understand and treat the causes of acquired neuropathic foot deformities. A
      successful foot specific intervention that improves MTPJ alignment will provide a
      non-invasive option to halt or slow the cascade of events leading to major lower extremity
      amputation, while improving function and minimizing disability.
    

Intervention name(s): Foot exercise; Shoulder exercise
Intervention type(s): Other; Other
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Other