Clinical History
57-year-old male patient with one-year history of bilateral groin pain and leg discomfort (right more than the left), but initially involving the left.
Imaging Findings
Axial and coronal MR images show organizing intramuscular haematomas in both iliacus muscles, more extensive and with evidence of methaemoglobin in the right. Muscle oedema and varying degrees of atrophy are also noted involving the left sartorius, pectineus and rectus femoris muscles, left vastus lateralis and vastus intermedius muscles reflecting denervation changes.
Discussion
The femoral nerve arises from the posterior branch of the ventral rami of the L2-L4 roots, descends through the psoas muscle and courses between the psoas and iliacus groove before exiting the pelvis below the inguinal ligament in close proximity to the femoral artery and vein [1].
As described by Goodfellow et. al., spontaneous iliacus haematomas may be common in patients with haemophilia, other blood coagulation disorders or individuals currently on anticoagulants. Based on their anatomic observations, it is the strong iliacus fascia enclosing the compartment containing both the femoral nerve and the iliacus muscle that contributes to the femoral compression. The haematoma that is responsible for femoral nerve palsy is necessarily situated in the iliacus muscle and not in the psoas muscle. The resulting mass effect from the haematoma compresses the femoral nerve against the psoas muscle tendon and induces an ischaemic femoral neuropathy. An iliacus muscle haematoma never drains spontaneously and persists for a long period of time, eventually resulting in chronic compression of the femoral nerve [2].
In a patient with blood coagulation disorder or one who is currently on anticoagulation therapy and who suddenly experiences groin or leg pain, the clinician should have a strong suspicion of femoral palsy due to spontaneous haematoma formation. MR imaging is the modality of choice as it demonstrates both the presence of haemorrhage and evidence of nerve compression [3].
Initial management involves stopping the bleeding, symptom relief and prevention of further nerve damage. The patient with haemophilia is given fresh frozen plasma or a more potent concentrate of human antihaemophilic globulin if plasma proves ineffective. If the hematoma is small or if the patient presents with evidence of clinical improvement, conservative treatment including bed rest and the correction of blood coagulation disorder are preferred. Once neurologic compromise is suspected or if MRI shows evidence of denervation changes such as muscle oedema or atrophy, surgical options such as haematoma evacuation and percutaneous drainage need to be considered [2, 4-5].
Differential Diagnosis List
Femoral nerve palsy resulting from bilateral iliacus heamatomas in a haemophiliac patient
Iliopsoas abscesses
Iliac fractures
Final Diagnosis
Femoral nerve palsy resulting from bilateral iliacus heamatomas in a haemophiliac patient
