A 13-year-old boy is seen in the office for persistent right knee pain. He first noticed a dull pain along the anterior knee 2 months ago. Initially, the pain was noticeable only after basketball practice. Two days ago, the pain worsened after the patient landed during a rebound attempt at a basketball game. The knee pain is now constant and not relieved with ibuprofen or ice. The patient has no chronic medical conditions. Temperature is 37.4 C (99.3 F). Height is at the 75th percentile, and weight is at the 95th percentile. The patient walks with a limp with the right foot pointed laterally. There is no tenderness, erythema, or swelling around the right knee. The anterior and posterior drawer tests are normal. No abnormal findings during knee flexion and extension are present with either internal or external rotation of the tibia. Range of motion of the right hip is limited, and the knee points laterally upon passive hip flexion. Which of the following is the most likely diagnosis in this patient?

Question

A 13-year-old boy is seen in the office for persistent right knee pain.  He first noticed a dull pain along the anterior knee 2 months ago.  Initially, the pain was noticeable only after basketball practice.  Two days ago, the pain worsened after the patient landed during a rebound attempt at a basketball game.  The knee pain is now constant and not relieved with ibuprofen or ice.  The patient has no chronic medical conditions.  Temperature is 37.4 C (99.3 F).  Height is at the 75th percentile, and weight is at the 95th percentile.  The patient walks with a limp with the right foot pointed laterally.  There is no tenderness, erythema, or swelling around the right knee.  The anterior and posterior drawer tests are normal.  No abnormal findings during knee flexion and extension are present with either internal or external rotation of the tibia.  Range of motion of the right hip is limited, and the knee points laterally upon passive hip flexion.  Which of the following is the most likely diagnosis in this patient?

Quizplus · Accepted Answer

11ec25c8_d979_d60a_bc81_177fa638ca1f_MD0003_00 Slipped capital femoral epiphysis (SCFE) is characterized by anterolateral and superior displacement of the proximal femur along the physis (growth plate). It most commonly presents in obese adolescents with chronic hip pain. However, 15% of patients with SCFE have only referred thigh or knee pain, as seen here. Due to the referred nature of the pain, knee examination is normal. Characteristic findings on hip examination, however, include limited internal rotation, which causes the foot to point laterally, and thigh abduction and external rotation with passive hip flexion. displacement of the proximal femur Bilateral hip x-rays are diagnostic for SCFE and show a posteriorly displaced femoral head. The patient should be non-weight bearing to avoid further slip and referred for immediate surgical screw fixation of the physis. posteriorly displaced femoral head (Choice A) Following a knee injury, anterior cruciate ligament tear presents with pain, swelling, and a popping sensation in the knee. Anterior translation of the proximal tibia upon pulling the tibia forward (or a positive anterior drawer test) is typical (not seen in this case). anterior drawer test (Choice B) Medial meniscus tear usually occurs after a twisting injury and presents with knee pain and swelling. Findings typically include a palpable click during knee extension with internal or external tibial rotation (positive McMurray test), not seen in this patient. McMurray test (Choice C) Osgood-Schlatter disease, or osteochondritis of the tibial tubercle, is a common cause of chronic knee pain that is worse with running and jumping in active adolescents. However, tenderness over the tibial tubercle would be present on examination (not seen in this case). (Choice D) Osteoarthritis of the hip presents with chronic hip pain and stiffness. It is more common in obese patients but typically does not occur until age >50. (Choice E) Osteoid osteoma is a benign bone tumor that typically occurs at the proximal femur and causes nighttime leg pain in adolescents. In contrast to this patient's presentation, pain associated with osteoid osteoma is unrelated to activity and relieved with ibuprofen. (Choice G) Transient synovitis of the hip typically presents in children age 3-8 with acute hip pain, often after a viral illness. This patient's age and chronic symptoms make SCFE more likely. Educational objective: Slipped capital femoral epiphysis is most common in obese adolescents and occurs when the proximal femur is displaced relative to the epiphysis along the growth plate. Knee pain may be the only presenting symptom. Supportive examination findings include limited hip flexion and internal rotation. References: Patterns of pain in adolescents with slipped capital femoral epiphysis. (http://www.ncbi.nlm.nih.gov/pubmed/30454962) Slipped capital femoral epiphysis in atypical patients. (http://www.ncbi.nlm.nih.gov/pubmed/27064469)

A 13-Year-Old Boy Is Seen in the Office for Persistent