A 15-year-old male presented with a painful soft-tissue swelling of the bilateral bimalleolar region.
A 15-year-old male figure skater presented with a painful soft-tissue swelling of the bilateral bimalleolar region. The pain had been present for two months and there was no history of trauma. MR imaging was performed and showed the presence of subcutaneous, focal soft-tissue masses of the bimalleolar region; the findings correlated to the level of the shoe rim, confirming the suspected MR imaging diagnosis of an impingement syndrome. The MR imaging study was performed using an RM scanner (0.2) with a dedicated coil. The examination consisted of T1- weighted spin-echo (SE), PD-weighted turbo-spin-echo (TSE), T2*-weighted gradient-echo (GE) and GE-STIR sequences, performed in the axial, sagittal and coronal planes.
Foot bursae are divided into anatomical bursae and acquired adventitial bursae, which commonly develop over the areas of bunion. There are many anatomical bursae in the foot that can occasionally be identified in patients on MR imaging, such as the bursae located on the medial and lateral plantar surfaces of the first and fifth metatarsals or the retrocalcaneal bursa, which is located between the calcaneus and the Achilles tendon. Anatomical bursae are closed sacs lined by a synovial-like membrane that contain synovial fluid and are subject to friction. Their purpose is to lessen normal friction and thus ease the motion that occurs between tendons, between the bones and skin, or between the tendons and ligaments. Bursae are found in numerous locations throughout the body and are classified according to their location, into deep bursae and subcutaneous bursae. The malleoli normally do not have anatomical bursae; malleolar adventitious bursae often result from abnormal contact pressure and shear forces that arise between the bony malleoli and the skater’s boot. The bony prominences of the malleoli have little inherent soft tissue to cushion them from this excessive pressure. The body responds to this abnormal stress by developing an adventitious bursa at this specific point and the newly developed adventitious bursae are suboptimal. These bursae develop by definition over time as a result of excessive pressure from ill-fitting skates. Adventitial bursae have a thinker fibrous wall than normal bursae and are more susceptible to inflammatory changes. Most bursitis cases can be categorized as aseptic bursitis, which can be labeled according to the cause as being traumatic, rheumatoid, metabolic, or neoplastic. The symptoms are related to the size and location of the bursitis, correlating to the focally painfull, clinically palpable soft-tissue mass. The bursae have a distinctive MR appearance, showing a homogeneous high signal intensity in relation to muscle on T2*-weighted GE and GE-STIR sequences, and appearing hypo-isointense on T1-weighted SE and PD-weighted TSE sequences. Bursitis must be differentiated from a soft-tissue tumor and a pseudotumor, for which the MR imaging technique plays a central role. Nonoperative measures usually provoke the best response in bursitis of the malleoli. The first-line treatment includes inspecting the skates for points that might be too tight around the malleoli. These areas can be stretched out using a ball-and-ring device that can be found at most shoe shops. The final nonoperative measure involves the cessation of skating. For patients who find no relief with the nonoperative measures mentioned, surgical excision is decisive.
Bimalleolar adventitial bursae.
Based on the provided MRI images of both ankles, a relatively well-defined fluid signal can be seen in the soft tissue areas of the medial and lateral malleoli. For instance, it appears as high signal intensity on T2* and STIR sequences, and as low to isointense signal on T1-weighted or PD sequences, indicating a cystic lesion suggestive of synovial or synovial-like fluid collection. The lesion is mostly located in the subcutaneous region near the bony prominence of the ankle joint, and there is no obvious large-scale bone erosion or destruction in the surrounding soft tissue. The local articular surfaces appear to remain generally intact.
Considering the patient’s age (15 years), clinical presentation (sports-related, noticeable ankle prominence, and soft tissue pain), and the cystic high-signal lesion seen on MRI, the most likely diagnosis is “ankle bursitis” caused by friction or pressure, more specifically referred to as “adventitial bursitis.” Other differential diagnoses can be ruled out with clinical signs and laboratory tests.
Combining the painful soft tissue swelling over the bony prominences on both ankles, the MR findings, and the common clinical etiology, the most probable diagnosis is traumatic (acquired) adventitial bursitis of the ankle. If there is still uncertainty, fluid aspiration from the bursa under ultrasound guidance (such as routine analysis, bacterial culture, etc.) can be performed to confirm and exclude any infectious causes.
1. Conservative Treatment
- Offloading and Rest: Avoid or reduce sports activities involving repeated friction or prolonged pressure. For ice skating or any activity that might cause high-pressure friction around the ankles, consider pausing or reducing intensity.
- Footwear Adjustment: If tight ice skates or daily shoes cause lateral compression of the ankle, use a professional shoe stretcher or custom orthotics to reduce friction and pressure in that area.
- Physical Therapy and Anti-inflammatory Measures: Local cold or warm compresses and physical therapy modalities (e.g., ultrasound, laser therapy) can help relieve mild inflammation and pain. If necessary, use short-term oral or topical nonsteroidal anti-inflammatory drugs (NSAIDs) under a doctor’s guidance.
2. Surgical Intervention
If conservative treatment fails or if the bursa becomes excessively large or recurrent, affecting normal activities, surgical removal of the affected bursa may be considered. Potential complications (such as infection or local scarring) should be assessed prior to surgery.
3. Rehabilitation and Exercise Prescription
- Early Stage (Acute Phase): Emphasize rest, immobilization, and anti-inflammatory strategies. Reduce weight-bearing and jumping activities as appropriate, while maintaining gentle joint mobility to prevent stiffness.
- Mid Stage (Recovery Phase): Once inflammatory symptoms have noticeably subsided, gradually increase lower limb strength training (e.g., light resistance exercises for the ankle), along with coordination and proprioception training (such as single-leg balance). Limit training to about 15-20 minutes each session, 2-3 times per week, with a gradual increase in intensity.
- Late Stage (Strengthening Phase): After symptoms have significantly improved, enhance joint stability training, such as ankle stabilization exercises with a small resistance band, alternating tiptoe and heel landings. Gradually return to sports-specific activities (e.g., ice skating), increasing intensity and duration step by step.
- FITT-VP Principle: Increase exercise frequency (Frequency) from 2-3 times per week to 3-4 times per week. Gradually raise exercise intensity (Intensity) from moderate (RPE 3-4) to a higher level. Extend the duration (Time) of each session from 15-20 minutes to about 30 minutes. Choose exercise modes (Type) that do not exacerbate ankle pressure (e.g., swimming or stationary cycling as cross-training). Progression (Progression) should be adjusted dynamically according to pain and joint response to ensure safety and effectiveness.
This report is a reference analysis based on the patient’s provided medical images and history. It is not a substitute for in-person consultation or professional medical advice. If you have any doubts or if symptoms worsen, please seek immediate medical attention and follow the guidance of a specialist.
Bimalleolar adventitial bursae.
