Changes to muscle and fascia tissue after eighteen days of ankle immobilization post-ankle sprain injury: an MRI case study.

Background: Ankle sprains often result in muscle atrophy and reduced range of motion, which can cause long-term ankle instabilities. Understanding the changes to muscle-such as atrophy-and concomitant changes to deep fascia-which may thicken alongside muscle loss-after ankle sprain injury is important to understanding structural changes about the joint and how they might contribute to longer-term impairments. Here, we employ advanced MRI to investigate skeletal muscle and fascial structural changes during the recovery period of one patient undergoing immobilization after ankle sprains.

Material And Methods: In this case study, a participant who suffered an ankle sprain underwent initial MRI scans and, after 21 days (18 of which included immobilization), a follow-up MRI. Techniques used included proton density, 3D stack of spirals, and diffusion tensor imaging to analyse muscle and fascia changes pre- and post-injury.

Results: Results showed muscle atrophy in most shank muscles, with volume loss ranging from no change in the lateral gastrocnemius to 12.11% in the popliteus. Thigh muscles displayed hypertrophy of 6% in the hamstrings, while the quadriceps atrophied by 2.5%. Additionally, fascia thickness increased from 0.94 mm to 1.03 mm. Diffusion tensor imaging indicated that the biceps femoris experienced the most significant changes in physiological cross-sectional area, while the rectus femoris showed minimal change.

Conclusion: The findings highlight the variable responses of muscles and a notable thickening of deep fascia post-injury, underscoring its role in recovery from ankle sprains.