A 65-year-old man comes to the office due to right lower abdominal pain that radiates to his groin and difficulty walking for the past week. Climbing stairs has been particularly hard for him, and he has fallen several times due to knee buckling. Medical history is significant for diabetes mellitus, hypertension, and atrial fibrillation. The patient takes warfarin for chronic anticoagulation. On physical examination, the right patellar reflex is decreased compared to the left. Abdominal CT scan is shown below: Which of the following additional findings is most likely to be seen in this patient?

Question

A 65-year-old man comes to the office due to right lower abdominal pain that radiates to his groin and difficulty walking for the past week.  Climbing stairs has been particularly hard for him, and he has fallen several times due to knee buckling.  Medical history is significant for diabetes mellitus, hypertension, and atrial fibrillation.  The patient takes warfarin for chronic anticoagulation.  On physical examination, the right patellar reflex is decreased compared to the left.  Abdominal CT scan is shown below:  Which of the following additional findings is most likely to be seen in this patient?

Quizplus · Accepted Answer

11ec160b_35e4_7aea_9249_1de3cdfd03db_MD0001_00 This patient's CT scan reveals a large fluid collection in the right retroperitoneum anterior to the psoas muscle. The fluid is isodense compared with muscle and displaces the right kidney. These findings are consistent with a spontaneous retroperitoneal hematoma, which occurs most often in patients receiving anticoagulation therapy (eg, warfarin). Affected patients often present with acute, severe pain in the groin, lower abdomen, or back; injury to the femoral nerve can also occur due to its proximity. The femoral nerve descends through the psoas major muscle, emerges laterally between the psoas and iliacus muscle, and then runs beneath the inguinal ligament into the thigh. Femoral nerve mononeuropathy can occur due to trauma (eg, pelvic fracture), compression from a hematoma or abscess, or injury during surgery/childbirth. Findings of femoral neuropathy include quadriceps weakness (eg, difficulty with stairs, falling due to knee buckling), decreased patellar reflex, and sensory loss over the anterior and medial thigh and medial leg. (Choice A) Obturator nerve injury presents with weakness of thigh adduction and medial thigh sensory loss. It is most commonly seen as an iatrogenic complication of pelvic surgery. (Choice C) Peroneal nerve injury often presents with loss of dorsal foot sensation and foot drop due to weakness of foot eversion, dorsiflexion, and toe extension. It is typically caused by compression of the nerve at the proximal fibula (eg, from leg casting). (Choice D) Tibial nerve injury causes numbness at the sole and is typically associated with decreased inversion and plantarflexion of the foot and flexion of the toes. Common causes include knee trauma and tarsal tunnel syndrome. (Choice E) Weakened abduction of the thigh occurs with superior gluteal nerve injury and results in a Trendelenburg gait. There are no associated sensory deficits. Educational objective: Femoral nerve mononeuropathy can occur due to trauma; compression from a retroperitoneal hematoma or abscess, or injury during surgery or childbirth. Findings include quadriceps weakness, decreased patellar reflex, and sensory loss over the anterior and medial thigh and medial leg.

A 65-Year-Old Man Comes to the Office Due to Right