Author(s): VAN HEESWIJK, K., SPEK, D., FEDERICO, M., HOOGEVEEN, A., JANSSEN, L., SCHELTINGA, M., Institution: MÁXIMA MEDICAL CENTRE, Country: NETHERLANDS, Abstract-ID: 926

INTRODUCTION:
Patients possibly having chronic exertional syndrome of the anterior leg compartment (ant-CECS) require a confirmatory intra compartment pressure (ICP) measurement, but this invasive test is patient unfriendly and imprecise. Earlier ultrasound (US) studies suggested that morphology of the leg crural fascia covering the muscle may be different in CECS. Aim of this observational study was to analyse the curvature of the crural fascia in ant-CECS and healthy controls at rest and following a standard treadmill exercise. An US device, equipped with a pressure monitor that automatically acquires time-synchronized images at standardized lower leg landmarks with 10mmHg and 80mmHg externally applied probe pressure, was used (CPMX1, Compremium AG, Switzerland).
METHODS:
Between February 2023 and February 2024, patients with a history, physical examination and ICP above the Pedowitz criteria (ICP ≥15mmHg at rest, or ≥30mmHg or ≥20mmHg 1 and 5 minutes post-exercise, respectively) and healthy controls matched for sex, age and BMI underwent leg imaging with 10mmHg and 80mmHg external US probe pressure. The curvature of the fascia was measured before and after a standard treadmill test using novel mathematical modelling (extreme convex to extreme concave, +40 to -40).
RESULTS:
A total of 209 US images in 21 ant-CECS patients (13 males; age 31 ± 11; BMI 26 ± 5) who were 1:1 matched with 21 healthy controls (13 males; age 36 ± 14; BMI 24 ± 3) were analysed. With 10mmHg external pressure, fascia curvature at rest in ant-CECS and controls was not different (ant-CECS 18.6 ± 4.4 vs controls 17.5 ± 6.3, p=0.53). Thirty seconds and five minutes after exercise, the fascia was more convex in ant-CECS compared to controls (thirty seconds: ant-CECS 26.4 ± 5.8 versus controls 22.8 ± 5.4, p=0.05; five minutes: ant-CECS 24.3 ± 4.9 versus controls 20.1 ± 5.9, p=0.02). Curvature changes at 80mmHg external pressure were not different between groups.
CONCLUSION:
Following exercise, the crural fascia in patients with ant-CECS is more convex compared to healthy controls.

References
Pedowitz RA, Hargens AR, Mubarak SJ, et al. Modified criteria for the objective diagnosis of chronic compartment syndrome of the leg. The American Journal of Sports Medicine 1990;18(1):35-40.
Sellei RM, Wollnitz J, Reinhardt N, et al. Non-invasive measurement of muscle compartment elasticity in lower limbs to determine acute compartment syndrome: Clinical results with pressure related ultrasound. Injury 2020;51(2):301-06.
van Heeswijk K, Spek D, Muijsenberg J, et al. Reliability of Ultrasound Based Compressibility of the Lower Leg Anterior Tibial Muscle Compartment in Healthy Volunteers. International Journal of Sports Physical Therapy 2025;20(2) doi: 10.26603/001c.128284