Botulinum Toxin Effects on Plantar Ulcer Recurrence

Study Overview
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Brief Summary
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The purpose of this grant is to collect pilot data to assess the amount of botulinum toxin that needs to be injected into the calf muscles of subjects with diabetes mellitus, peripheral neuropathy, and a plantar ulcer to decrease muscle strength. We hypothesize that a decrease in plantar flexor muscle strength will temporarily decrease plantar pressure. The decrease in plantar pressure will provide temporary protection to the new tissue as it gains tolerance to high stress with the long term potential outcome as a decrease in the ulcer recurrence rate.

Detailed Description
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Please read Brief Summary

Official Title
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Botulinum Toxin Effects on Plantar Ulcer Recurrence

Conditions
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Diabetes Mellitus, Peripheral Neuropathy, Plantar Ulcers

Intervention / Treatment
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* Drug: Botulinum Toxin
* Drug: Saline


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Diagnosis of diabetes mellitus and determination of diminished or absent plantar sensation A recurrent forefoot plantar ulcer; at least the second occurrence of a plantar ulcer or a previous failure to heal a plantar ulcer with reasonable treatment intervention (Total contact casting, off loading boot, molded ankle foot orthotic, Gillette, or therapeutic footwear modifications) Ambulatory Exclusion Criteria: Active infection in the involved foot Previous botulinum toxin injections Ulcers on the dorsal surface of the foot Ankle-brachial index <0.45 History of cerebral vascular accident or other neurological problems complicating their rehabilitation Women of childbearing years unless pregnancy test is agreed upon, completed, and negative and agree to use some form of contraception during the study. Current drug therapy that includes an anticoagulant History of a neuromuscular disease, except peripheral neuropathy as a result of diabetes mellitus
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: 1<br>Placebo (saline) injections into 6 sites in the calf muscle | Drug: Saline<br>* Placebo (saline) (3cc). Injection are given at one session. 2 injections into the medial gastrocnemius, 2 injections into the lateral gastrocnemius, and 2 injections into the soleus<br>|
| Active Comparator: 2<br>Total 200 units of Botulinum Toxin injected into 6 sites into the calf muscles. | Drug: Botulinum Toxin<br>* 200 units of botulinum toxin, and 300 units of botulinum toxin. Injection are given at one session. 2 injections into the medial gastrocnemius, 2 injections into the lateral gastrocnemius, and 2 injections into the soleus<br>* Other names: botox;|
| Active Comparator: 3<br>300 units of botulinum toxin injected into 6 sites in the calf muscle | Drug: Botulinum Toxin<br>* 200 units of botulinum toxin, and 300 units of botulinum toxin. Injection are given at one session. 2 injections into the medial gastrocnemius, 2 injections into the lateral gastrocnemius, and 2 injections into the soleus<br>* Other names: botox;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Plantar Flexor Muscle Strength | Concentric plantar flexor torque was assessed using the Biodex System 3 Pro Orthopedic Testing & Rehabilitation dynamometer. Plantar flexor peak torque was measured at 60 deg/sec, which is comparable to the angular velocity of the ankle joint during the stance phase of walking. Three trials of each foot were completed. Peak torque was calculated as the average of the two highest torque values across trials and results were expressed as Nm. A positive value represents an increase in torque while a negative value represents a decrease in torque. | Pre-treatment, 2 weeks after injection, upon ulcer healing, 3 months and 6 months after ulcer healing | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Barefoot Plantar Pressure | Novel emed pressure platform was used for data collection. A two-step method of data collection was used and a minimum of two trials of each foot were recorded. The plantar pressure map was divided into 3 horizontal masks using Percent Mask software and peak plantar pressure was determined for the forefoot region. Results are expressed in N/cm^2. | pre-injection, 2 weeks post injection, post healing, and 3 and 6 months post healing | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Diabetes mellitus, plantar ulcers, peripheral neuropathy