Module 57, General Orthopaedist Level

This is a 12 year old girl who presented with a chief complaint of left knee pain on the medial aspect of the proximal tibia. The pain was described as a dull, aching pain present for one year's time, occasionally awakening her from sleep and occasionally worsening with sports activities. Her past medical history was essentially unremarkable. There was a questionable family history for "bony tumors". Physical examination revealed full range of motion of all her extremities. She was neurovascularly intact. DTR's were normal and symmetric. Palpation at the left knee revealed an asymptomatic mass at the distal femur medially and a painful protrusion at the medial proximal tibia. X-rays of her left knee in the AP/lat/oblique views revealed multiple exostoses of the distal femur and proximal tibia. These were also noted in bilateral forearm films at the proximal and distal poles.

Question 57A

This history and these x-rays together are not consistent with multiple exostosis.

Question 57B

Both the tibial and femoral exostosis should be excised.

Question 57C

Exostosis are the most common bone tumors.

Question 57D

The etiology of these exostoses are developmental physeal growth defects.

Question 57E

Growth of the exostosis occurs by enchondral ossification of the cartilage cap mimicking physeal growth.