Overview
This randomized controlled trial investigates the effectiveness of Functional Magnetic Stimulation (FMS) as an adjunct to physiotherapy in athletes with MRI-confirmed bone marrow edema of the lower limb. Forty athletes with Fredericson grade 2-3 edema will be randomly assigned to receive either physiotherapy plus FMS or physiotherapy alone for four weeks. Clinical, functional, and imaging assessments will be conducted up to 16 weeks. Primary outcomes include pain intensity, lower-limb function, return-to-sport readiness, and MRI indicators of bone marrow edema. The study aims to determine whether adjunctive FMS enhances recovery and accelerates the resolution of bone marrow edema compared with standard physiotherapy.
Description
Background: Bone marrow edema is a reversible stress-related bone injury in athletes, causing localized pain during loading and confirmed by MRI, the gold standard for diagnosis and monitoring. Grades 2 and 3 of the Fredericson classification represent clinically significant edema without a fracture line and are managed conservatively through physiotherapy including exercise, manual techniques, and gradual reloading. Functional Magnetic Stimulation (FMS) is a non-invasive method that induces deep neuromuscular activation and improves circulation. Although increasingly used in musculoskeletal rehabilitation, its effect on recovery from bone marrow edema has not yet been tested in a controlled clinical setting.
Aim: The aim of the present randomized controlled clinical trial is to evaluate the effectiveness of adding Functional Magnetic Stimulation to a structured physiotherapy rehabilitation program in athletes with MRI-confirmed bone marrow edema of the lower limb. The primary objective is to determine whether the combined approach results in greater clinical improvement, superior functional recovery, and faster radiological resolution of edema compared with physiotherapy alone.
Method: Forty athletes with lower-limb bone marrow edema graded as Fredericson 2 or 3 on MRI will be randomly assigned to two groups. The intervention group will follow a four-week physiotherapy program combining therapeutic exercise, manual therapy, and unloading techniques with Functional Magnetic Stimulation applied twice weekly. The control group will receive the same physiotherapy without FMS. Assessments will occur at baseline, two, four, and sixteen weeks, including pain (NRS 0-10), functional ability (LEFS-GR), and readiness for return to sport (Tegner scale). MRI at baseline, week 4, and week 16 will evaluate Fredericson grade, edema intensity, and edema extent. All parameters are predefined as primary outcomes. Data will be analyzed with mixed-model ANOVA for repeated measures with the significance level set at p \< .05.
Expected Results: It is anticipated that athletes receiving Functional Magnetic Stimulation in addition to physiotherapy will show greater pain reduction, improved lower-limb function, faster MRI-documented resolution of bone marrow edema, and earlier readiness to return to sport compared with physiotherapy alone.
Eligibility
Inclusion Criteria:
- Athletes aged 18-45 years participating in regular sports training ≥3 sessions per week for the past 6 months.
- MRI-confirmed bone marrow edema (BME) of the lower limb graded as Fredericson 2 or 3.
- Onset of pain or symptoms within the previous 6 weeks.
- Pain intensity ≥4/10 on the Numeric Rating Scale during loading activity.
- Ability to comply with the 4-week intervention and 16-week follow-up assessments.
- Written informed consent provided prior to participation.
Exclusion Criteria:
- Fredericson grade 4 or evidence of a fracture line on MRI. Bone marrow edema secondary to infection, tumor, or systemic inflammatory disease.
- History of recent fracture, surgery, or intra-articular injection in the affected limb within 12 weeks.
- Prior exposure to Functional Magnetic Stimulation or Extracorporeal Shockwave Therapy within 8 weeks before enrollment.
- Presence of metallic implants, pacemaker, or other contraindications to magnetic stimulation.
Pregnancy or breastfeeding. Use of systemic corticosteroids or medications affecting bone metabolism. Any neurological, metabolic, or cardiovascular condition interfering with safe participation.