A 15-month-old boy is brought to the office for evaluation of bowed legs. The boy's mother says that his legs have always been slightly bowed, but the bowing appears to have worsened since he started walking a month ago. The patient does not appear to be in pain and is still able to play outside. He eats a varied diet and drinks 16 ounces of whole milk a day. He is an only child and was born at full term via vaginal delivery with no complications. The patient is at the 40th percentile for height and the 25th percentile for weight. On examination, he has full range of motion of bilateral hips and knee and ankle joints. The legs are of equal length and have no joint effusions. When the boy stands with his feet together, there is a tibiofemoral outward bend that results in a gap between the knees. The remainder of the examination is unremarkable. Which of the following is the best next step in management of this patient?

Question

A 15-month-old boy is brought to the office for evaluation of bowed legs.  The boy's mother says that his legs have always been slightly bowed, but the bowing appears to have worsened since he started walking a month ago.  The patient does not appear to be in pain and is still able to play outside.  He eats a varied diet and drinks 16 ounces of whole milk a day.  He is an only child and was born at full term via vaginal delivery with no complications.  The patient is at the 40th percentile for height and the 25th percentile for weight.  On examination, he has full range of motion of bilateral hips and knee and ankle joints.  The legs are of equal length and have no joint effusions.  When the boy stands with his feet together, there is a tibiofemoral outward bend that results in a gap between the knees.  The remainder of the examination is unremarkable.  Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

Explanation: 11ec25c8_d739_f828_bc81_cff0cc586127_MD0003_00 Genu varum (bowlegs) is a condition in which the legs angulate away from midline, causing a gap between the knees. This child likely has physiologic genu varum, a normal bowing that appears from birth to age 2 due to expected lower extremity alignment changes. This angulation is often noticeable as the child begins to walk around age 12-15 months. Characteristics of physiologic genu varum include: Symmetric bowing Normal stature No leg length discrepancy No lateral thrust when walking Diagnosis is clinical. Management is reassurance and observation as physiologic genu varum resolves by age 2. (Choice A) Leg x-rays are indicated for suspected skeletal dysplasia (eg, achondroplasia). Although skeletal dysplasia can present with symmetric bowing, short stature and dysmorphic features are expected. (Choice B) Leg orthotics and physical therapy are indicated in patients with leg deformity (eg, hip subluxation), contractures (eg, cerebral palsy), or weakness (eg, foot drop), none of which are seen in this patient. Orthotics were previously used for physiologic genu varum but are no longer recommended as the angulation corrects itself. (Choice D) Surgical correction is appropriate for Blount disease, a pathologic cause of bowlegs due to abnormal cartilage growth. These patients often have leg length discrepancy, asymmetrical bowing, and lateral thrust with ambulation. (Choice E) Vitamin D and calcium supplementation treats rickets, which can present with lower extremity bowing and short stature. Additional findings include frontal bossing and bowing of the upper extremities as well. This patient has a well varied diet, normal height, and no other abnormal examination findings, making rickets unlikely. Educational objective: Symmetric genu varum, or bowed legs, is typically physiologic from birth and resolves by age 2. Management is reassurance and observation. References: Management of bow legs in children: a primary care protocol. (http://www.ncbi.nlm.nih.gov/pubmed/28459895)

A 15-Month-Old Boy Is Brought to the Office for Evaluation