A 4 Year Old Boy Presented With Trouble Walking

A 4 year old boy is brought to a pediatrician because his mother has noticed that he has been limping for several days. She says she cannot recall any trauma or fall sustained by the child in the past week. During this time the child has been hesitant to walk much and has asked to be carried by his parents. He has started to complain that his left hip hurts. There is no history of fever or any sick contacts. The child has not complained of pain in any other joint. There is no significant past history or any history of inflammatory arthropathies in the family.

Physical Examination:

• The child appears to be a healthy boy in no acute distress. 
• He is mildly uncomfortable with range of motion of his left hip 
• No abnormal sounds are elicited with motion of the left hip
• Range of motion is normal and painless in all other joints.
• When asked to walk , the child is notable for a Trendelenburg limp on left side. 
• All the other organ systems are normal on examination.

His Vitals Are:

Temp : 98.7 F

HR: 90 b/min

RR: 18 b/min

BP: 110/70 mmHg

What is The Differential Diagnosis:

• Septic Arthritis
• Developmental dysplasia of hip joint
• Juvenile rheumatoid arthritis
• Legg-Calve Perthes disease
• Slipped capital femoral epiphysis
• fracture

X Ray of the Pelvis and the Hip Joints is shown below:

The x ray above shows asymmetry of the hips with the right hip appearing normal, while the left hip is notable for a small and incomplete femoral head and a widened joint space. There are no fractures or dislocation seen.

Final Diagnosis: Legg- Calve Perthes disease. 

Case Discussion:

• Avascular necrosis of the epiphysis of the femoral head related to its fragile blood supply.
• Most commonly seen in children age 3 to 8 years
• Insidious onset of hip pain or presents with painful/ painless limp.
• There is decreased range of motion of the affected joint.
• X-ray of the hip will demonstrate hip asymmetry and the affected hip will have some degree of femoral head collapse followed by gradual regrowth. 
• Treatment aims in the fact that femoral head must be contained within the acetabulum by bracing or surgical reconstruction.
• Acetabular osteotomies may be needed in cases where permanent hip dysplasia develops.
• The prognosis is dependent on the ability to keep the femoral head contained within the acetabulum and the age of the patient. 
• Patients over 6 years of age tend to have worse outcomes on average compared to younger patients. 

Clues To Diagnosis Is The Case Mentioned Above:

1. History of painful limp and insidious onset

2. Decreased range of motion in the affected hip on physical examination

3. Appearance on the pelvic x ray.