Review Question - QID 5548

The patient has acute hematogenous osteomyelitis (AHO) of the distal femur with associated subperiosteal abscess. If growth arrest occurs at an early age, limb length inequality and angular deformity may result.

The most serious complications of AHO and its treatment include chronic infection, multi-system infection, growth disturbance, venous thromboembolic disease, avascular necrosis, fracture and adverse drug events from antibiotic treatment. Limb length inequality becomes most apparent at 9 years of age, on average. Follow up until skeletal maturity is recommended. The amount of growth disturbance will be directly proportional to the amount of destruction sustained by the physis during the acute infection, as well as the portions of the physis involved.

Langenskiöld noted growth disturbance after osteomyelitis in seven children, affecting either the medial or lateral distal femur. Onset of infection in his review was in the first four weeks of life. Angular deformities of 20 to 50 degrees were found in late follow up and were treated with supracondylar osteotomy.

Figures A through C show abnormal signal intensity in the distal lateral femur consistent with osteomyelitis and a low signal fluid collection posterior to the distal femur consistent with subperiosteal abscess.

Incorrect answers:
Answer 2: Osteonecrosis of the femoral head is more commonly associated with septic arthritis of the hip.
Answer 3 and 4: This presentation is more consistent with an infectious than oncologic diagnosis.
Answer 5: Hyperparathyroidism is not a late complication of AHO.