A 12-year-old girl, without significant medical history, was referred from her general practitioner for an MRI examination of the knee due to worsening knee pains, especially in the right knee. An MRI was performed to exclude a meniscal tear.
A focal spot of bone marrow edema was seen at the level of the physis in the lateral femoral condyle. There was no associated meniscal tear. Other findings were normal.
FOPE zones, or focal periphyseal oedema zones, are areas of bone marrow oedema that are primarily localized around the physes of the distal femur, proximal tibia of proximal fibula. They can extend into both the adjacent metaphysis and epiphysis. FOPE zones can be seen in both males and females. The presentation in males (typically around the ages of 13-14) is somewhat later than in females (around the ages of 11-12) due to later skeletal maturation.
The exact cause of FOPE is still unknown. They're regarded to be potentially painful manifestations of the physiologic physeal fusion. It is suggested that as the physis of the long bones begins to close, endochondral ossification occurs with small bony bars before complete fusion. These bars may act as anchors to the surrounding bone, which thereby alters the local mechanics resulting in small amounts of vascular damage and bleeding in young, active adolescents. [1]
Conventional X-rays of the knee will appear normal, since bone marrow oedema cannot be seen on a plain radiograph. The imaging modality of choice consist of an MRI of the knee, which can demonstrate the focal zones of increased periphyseal T2 signal, consistent with focal bone marrow oedema.
Although FOPE zones may be symptomatic and may be a cause of pain, they do not require treatment. FOPE is a self-limiting condition with spontaneous resolution over time. [2]
No follow-up imaging is needed.
Teaching points: FOPE zones may be a symptomatic manifestation of early physiologic physeal closure.
Focal periphyseal edema zone (FOPE)
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The MRI scan shows focal areas of high T2 signal near the distal femoral and proximal tibial metaphysis of the right knee. These signals are primarily around the physis (growth plate), partially extending toward the metaphysis and epiphysis, demonstrating varying degrees of bone marrow edema. There is no obvious soft tissue swelling or effusion. The articular cartilage surface of the knee joint is smooth. The meniscus shape and signal appear generally normal without clear signs of tearing. The cruciate and collateral ligaments appear morphologically and signal-wise normal.
Given the patient’s age (12 years old, during a rapid adolescent growth phase), symptoms (knee pain), and imaging findings (focal bone marrow edema signals near the growth plate), the most likely diagnosis is FOPE (Focal Periphyseal Edema) zone. This condition is typically related to gradual fusion of the physis during growth and may cause pain but usually does not require special intervention.
Since no significant structural damage is evident on imaging, the rehabilitation and exercise prescription focus on alleviating symptoms, maintaining joint range of motion, and safely transitioning back to normal exercise levels. The FITT-VP principle is recommended (Frequency, Intensity, Type, Time, Volume/Progression).
This report is merely a reference analysis based on current clinical and imaging data, and it cannot replace an in-person evaluation or professional medical advice. If the patient experiences persistent or worsening symptoms, it is advised to visit a qualified hospital for further examination and treatment.
Focal periphyseal edema zone (FOPE)
