Treatment of Lower Leg Anterolateral Chronic Exertional Compartment Syndrome With Intra-muscular Botulinum Injections.

Chronic exertional compartment syndrome (CECS) of the lower leg muscle compartments is a common problem in the active population. The condition often significantly restricts patients from participating in their desired activity to the best of their ability. The pathology of CECS is related to increased intra-muscular pressure related to a restrictive fascia (envelope around the muscle or muscle group). The current standard of care for definitive treatment of CECS is a surgical fasciotomy. However, there have been a number of case reports reporting successful reduction of the symptoms of CECS with intra-muscular botulinum injections. Intra-muscular botulinum injections may reduce the symptoms of CECS by potentially decreasing muscle activation, therefore diminishing blood flow, which may reduce intra-compartmental muscle expansion and pressure of the compartment during exercise. Thus botulinum injections might provide a non-operative method of treating CECS.

This study will determine the effectiveness of intra-muscular botulinum injection, compared to a normal saline placebo, for treatment of lower leg anterolateral CECS, over a 24-week period. Participants will answer a web-based questionnaire before receiving the injection (Baseline) and at regular follow-up intervals at 2, 4, 6, 8, 12, 16, 24-weeks post-injection. The questionnaires will ask the participant to provide detailed information about their painful sport activity, and the maximum level of pain that they experience during that activity. They will also characterize the type of pain experienced, record the time to initial onset and duration of pain during the painful sport activity, and provide an overall measure of their leg function using a Single Assessment Numeric Evaluation (SANE) score. Participants will also attend an in-person appointment in clinic at Baseline, and at 6, 16 and 24-weeks post-injection for assessment of numbness and/or tingling in the foot, ankle instability, and manual ankle muscle power.

Inclusion criteria

• Confirmed diagnosis of lower leg anterolateral chronic exertional compartment syndrome (CECS), as measured post-exertional compartment pressure measurements of greater than 30 mmHg for immediate post-exertional compartment pressure, and greater than 12 mmHg at 5 minutes after stopping exercise.

Exclusion criteria

• Female patients who are pregnant, trying to get pregnant or lactating
• History of keloidal scarring
• History of any significant neurologic disease (ie: amyotrophic lateral sclerosis, motor neuropathy, myasthenia gravis, Lambert-Eaton syndrome)