A 67-year-old male patient presented at the emergency service with a history of chronic right lower limb pain worsening after low energy trauma. There was a previous history of varices surgery in the right lower limb.
The emergency plain radiography (Fig. 1) showed lytic, poorly defined, non-sclerotic, cortical lesion at the medial aspect of the right tibia. For further evaluation, an MRI of the right leg (Figs. 2, 3) was performed and demonstrated a vessel, in communication with the pretibial varices, that perforated the anterior cortex of the tibia, with a path through the tibial diaphysis to the posterior cortex, where it emerges into the great saphenous vein. The complementary computed tomography (CT) (Fig. 4) indicated the same findings of cortical defect in the tibia. Finally, the colour Doppler ultrasound (Fig. 5) demonstrated flow through the varicose vein perforating the anterior cortex of the tibia with signs of reflux during the compression manoeuvres. Based on the imaging findings, the diagnosis of pretibial varices with intraosseous venous drainage was confirmed.
Background
Although varicose veins are present in 10%–40% of people aged 30–70 years, the pathogenesis of leg varices remains poorly understood [1, 2, 3]. Increased age, Caucasian race and multiple pregnancies are important risk factors for varix formation [2, 3, 4]. Regardless of these factors, the pathogenesis of varicose veins in the lower extremities is mainly venous valvular dysfunction [1]. Some authors hypothesise that intraosseous venous drainage anomaly may be the cause of varices or deep venous thrombosis and conversely the consequence of venous insufficiency [1,4]. In most cases reported, intraosseous perforating vein incompetence occurred at the draining vein into the tibia, particularly the anterior tibial cortex [1].
Clinical Perspective
Most patients are symptomatic [4, 5]. Clinical presentation depends on the length of evolution and the importance of the reflux. It varies from pretibial varicosities to skin changes, including lipodermatosclerosis and leg ulcers [5].
Imaging Perspective
Imaging can make the diagnosis alone [2, 6]. Plain radiography of the mid tibia demonstrates a round osteolytic defect (2-4.5 mm diameter), perforating the anterior cortex of the bone [5]. This foramen communicates with a proximal, longitudinal radiolucent groove (‘‘double railway track aspect’’) [5]. No worrisome radiographic features like “moth-eaten” or permeative bone destruction, expansion of the medullary canal or soft tissue masses other than varices are present [2, 4].
Colour Doppler ultrasound is usually the first imaging modality and can confirm the presence of dilated veins as well as one varix lying adjacent to a cortical impression defect [1, 2, 3, 4]. However, the dilated intraosseous vein itself cannot be demonstrated because of the inability of the ultrasound waves to penetrate the bony cortex [2]. Furthermore, colour Doppler ultrasound can demonstrate reflux in the varix, which is a sign of valvular incompetence of the intraosseous vein [2].
CT findings of intraosseous perforating vein incompetence consisted of varices in the pretibial soft tissues, a dilated intraosseous nutrient vein, and an enlarged nutrient canal in the affected tibial diaphysis [1, 4]. Multiplanar reconstruction of venous CT scan demonstrates the transtibial route of the venous reflux, originating from the tibial veins, extending through a bony channel to the bone perforator and the varicosities [5].
Magnetic Resonance Imaging (MRI) may be the preferred method to confirm this intraosseous venous drainage anomaly [2, 3]. In some cases, MRI can also depict abnormal signal in the muscles of the symptomatic calf [4]. Moreover, MRI can also be used to rule out other vascular anomalies. Following sclerotherapy, MRI also served as method of monitoring the treatment response [7]. Postcontrast images can be obtained to evaluate for the presence of thrombus [2].
Take-Home Message/Teaching Points
The intraosseous venous drainage anomaly is a rare condition in which the diagnosis can be made by imaging findings alone, avoiding the misdiagnosing and allowing the correct management and treatment.
Intraosseous venous drainage anomaly
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Based on the X-ray, CT, and MRI images provided, the following major features are observed:
Overall, the imaging findings are consistent with “intraosseous venous drainage abnormality,” or “incompetence of an intraosseous perforating vein,” leading to local varicose veins. Considering the patient’s history of surgery for right lower limb varicose veins and chronic pain, these findings suggest the possibility of an “abnormal intraosseous perforating vein.”
Based on the imaging findings and the patient’s condition, the following diagnoses or differential diagnoses should be considered:
Considering the patient’s age, chronic right lower limb pain, previous varicose vein surgery, and imaging findings (enlarged nutrient canal in the midshaft of the tibia, subcutaneous varicose veins with evident retrograde flow), the most likely diagnosis is: “Intraosseous Perforating Vein Incompetence.”
If there is any clinical doubt, further vascular ultrasound, lower extremity venography, or MR venography may be performed to clarify hemodynamics and rule out other vascular anomalies.
For varicose veins caused by an intraosseous perforating vein abnormality, treatment aims to relieve venous hypertension, reduce pain, and prevent further complications. Consider the following strategies:
Rehabilitation/Exercise Prescription (FITT-VP Principle):
During rehabilitation, monitor changes in limb swelling, skin color, and pain level. If severe symptoms or signs of phlebitis occur, timely reevaluation and treatment adjustments are indicated.
This report is based solely on current imaging and the provided medical history. It is for reference only and does not replace in-person consultation or professional medical advice. Patients should follow clinical assessments and medical instructions for further examinations and treatment.
Intraosseous venous drainage anomaly
