|
Year |
2001 |
|---|---|
|
Question Number |
49. |
|
Category |
Select |
Question
The parents of a 3 year old girl report that she had a transient episode of diffuse left knee pain and a limp 1 week ago that lasted about 24 hours. History reveals no antecedent trauma, although the parents describe the child as being very active. She is afebrile and there is no obvious systemic illness. Examination does not elicit any clear locking or effusion. Radiographs of the hips are unremarkable; radiographs of the knee are shown in Figures 9a and 9b. Management should consist of
1- immobilization with the knee flexed to 45 degrees
2- immobilization with the knee in full extension
3- arthroscopic microfracture technique
4- fixation with absorbable pins
5- observation
Figures
Answer (click for answer)
Preferred Response : 5
The x-rays (9a, 9b) shown in the picture supplement to the OITE shows AP and lateral views of a pediatric knee with an apparent osteochondral defect on the medial femoral condyle. The history describes a transient episode of effusion and limping a week prior to the office visit. The child has an unremarkable physical exam and no current illness. What to do? The authors of the first paper listed below had the same question because they saw irregular distal femoral epiphyses so commonly in the asymptomatic children the saw in clinic. After review of the x-rays of 147 children (294 knees) without any musculoskeletal symptoms the authors’ concluded (and I quote):
1) Irregularities of the margin of the ossification center in the distal femoral epiphyses are extremely common in normal children.
2) Often the irregularities take a form radiographically indistinguishable from osteochondritis dissecans. Our data do not deny the existence of osteochondritis dissecans in the femora of children, but they do indicate that it is much less frequent than the marginal irregularities described.
3) The patients in this series were asymptomatic and, even in several omitted from the study because of mild symptoms, the changes disappeared without treatment.
4) The evidence strongly suggest that the x-ray appearance of osteochondritis dissecans can be simulated by a normal variant of ossification in children.
5) Since many of the irregularities are located on the posterior aspect of the femoral condyles, the irregularity will often be seen in the tunnel view, while the AP xray does not show it as clearly.
Reference: Caffey J, Madell SH, Royer C, Morales P: Ossification of the distal femoral epiphysis. J bone Joint Surg Am 1958; 40: 647-654.
Tolo VT: The lower extremity, in Morrissy RT, Weinstein SL (eds): Lovell and Winter’s Pediatric Orthopaedics, ed 4. Philadelphia, PA, Lippincott-Raven, 1996, pp 1047-1075.
Sales de Gauzy j, Mansat C, Darodes PH, Cahuzac JP: Natural course of osteochondritis dissecans in children. J pediatr Orthop B 1999;8:26-8.
Nawata K, Teshima R, Morio Y, Hagino H: Anomalies of ossification in the posterolateral femoral condyle: Assessment by MRI. Pediatr Radiol 1999;29:781-784.
Hefti F, Beguiristain J, Moller- Madsen B, et al: Osteochondritis dissecans: A multicenter study of the European Pediatric Orthopedic Society, J Pediatr Orthop B 1999;8:231-245.