Osteochondromas are benign bone tumors that form on the external surface of bones. They originate from within the periosteum as small cartilage-capped bony projections that grow in proportion with the patient during development. Most commonly found in the metaphysis of long bones, osteochondromas can cause pressure symptoms but usually cause no issues. Multiple hereditary exostoses is a genetic condition where multiple osteochondromas form due to mutations in EXT1/EXT2 genes. While generally benign, osteochondromas rarely develop into cartilage sarcoma with advanced age or large size. Surgical removal is indicated when they become symptomatic or suspicious for malignancy.

1. Dr MADAN MOHAN, Consultant ,
Orthopaedics, KIMS TRIVANDRUM
Osteochondroma
Dr Madan's Slide

2. • Developmental malformations rather
than true neoplasms and are thought
to originate within the periosteum as
small cartilaginous nodules.
• Lesions consist of a bony mass, often
in the form of a stalk, produced by
progressive endochondral ossification
of a growing cartilaginous cap.
Dr Madan's Slide

3. • Their growth usually parallels that of
the patient and usually ceases when
skeletal maturity is reached
• Usually are found on the metaphysis
of a long bone near the physis
• They are seen most often on the distal
femur, the proximal tibia, and the
proximal humerus. They rarely
develop in a joint
Dr Madan's Slide

4. Trevor disease (dysplasia
epiphysealis hemimelica)
refers to an intraarticular
epiphyseal
osteochondroma.
Dr Madan's Slide

5. • Many of these lesions cause no symptoms and
are discovered incidentally.
• Some cause mechanical symptoms by irritating
the surrounding structures, and rarely one
becomes painful due to a fracture.
• False aneurysms of major lower extremity
vessels as the result of pressure from
osteochondromas have been reported.
• Also, neuropathies caused by pressure from a
contiguous osteochondroma have occurred; the
physical finding usually is a palpable mass.
Dr Madan's Slide

6. • Multiple hereditary exostoses is an
autosomal dominant condition
with variable penetrance.
• Most patients with this disorder
have a mutation in one of two
genes: EXT1, which is located on
chromosome 8q24.11-q24.13, or
EXT2, which is located on
chromosome 11p11-12.
Dr Madan's Slide

7. • The most striking feature is the presenceof
many exostoses, but disturbances in
growth also occur, such as abnormal
tubulation of bones, producing broad and
blunt metaphyses, and sometimes bowing
of the radius and shortening of the ulna,
producing ulnar deviation of the hand.
• The disease occurs only 5% to 10% as
often as solitary osteochondroma and is
more common in males.
Dr Madan's Slide

8. • Osteochondromas are of two types:
pedunculated and broad based or sessile
• Pedunculated tumors are more common,
and any definite stalk is directed away
from the physis adjacent to which it takes
its origin.
• The projecting part of the lesion has
cortical and cancellous components, both
of which are continuous with
corresponding components of the parent
bone.
Dr Madan's Slide

9. SOLITARY OSTEOCHONDROMA, LUSCHKA’S
TUBERCLE. Scapula
Dr Madan's Slide

10. OSTEOCHONDROM
A AND
NON-OSSIFYING
FIBROMA.
Distal Femur
Dr Madan's Slide

11. Sessile Osteochondromas
Dr Madan's Slide

12. Cauliflower Osteochondroma
Dr Madan's Slide

13. Coat-hanger
exostosis
Dr Madan's Slide

14. OSTEOCHONDROMA WITH A LARGE
OSTEOCARTILAGINOUS CAP
Dr Madan's Slide

15. • The lesion is covered by a cartilaginous
cap that often is irregular and usually
cannot be seen on radiographs;
occasionally, calcification within the cap
may be seen.
• Typically, the cap is only a few millimeters
thick in adults, although it may be 2 cm
thick in a child.
• A bursa frequently overlies the tumor and
may contain osteocartilaginous loose
bodies. Dr Madan's Slide

16. • Malignant degeneration is extremely
rare.
• Large series have estimated the
incidence of malignant degeneration
to be approximately 1% for patients
with a solitary osteochondroma and
5% for patients with multiple
hereditary exostoses
Dr Madan's Slide

17. • Malignant transformation should be
suspected when a previously
quiescent lesion in an adult grows
rapidly; it usually takes the form of a
low-grade chondrosarcoma.
• In these cases, the cartilage cap
usually is more than 2 cm thick.
• Malignant transformation is best
evaluated by CT or MRI.
Dr Madan's Slide

18. • Surgery (en bloc resection) is indicated
when the lesion is large enough to be
unsightly or produce symptoms from
pressure on surrounding structures or
when imaging features suggest
malignancy.
• Recurrence is rare and probably is caused
by failure to remove the entire
cartilaginous cap.
• Patients with multiple hereditary
exostoses may require osteotomies to
correct deformity.Dr Madan's Slide

19. Dr MADAN MOHAN, Consultant ,
Orthopaedics, KIMS TRIVANDRUM
Hereditary Multiple Exostosis
Dr Madan's Slide

20. • An inherited autosomal dominant
metaphyseal overgrowth that is
characterized by multiple
osteochondromas
• Originally described by Boyer in
1814
Dr Madan's Slide

21. Common sites of HME
Dr Madan's Slide

22. • A characteristic bayonet hand deformity occurs
about the wrist as a result of retardation of
bone growth; the deformity is characterized by
shortening of the ulna, outward bowing of the
radius, and a subluxation of the radioulnar
joint
Dr Madan's Slide

23. Bayonet
Hand
Deformity
Dr Madan's Slide

24. Malignant
Degeneration
Dr Madan's Slide

25. Dr MADAN MOHAN, Consultant ,
Orthopaedics, KIMS TRIVANDRUM
14 yr old boy
March 2012
Dr Madan's Slide

26. Dr Madan's Slide

27. Dr Madan's Slide

28. Dr Madan's Slide

29. Dr Madan's Slide

30. Dr Madan's Slide

31. Dr Madan's Slide

32. Dr MADAN MOHAN, Consultant ,
Orthopaedics, KIMS TRIVANDRUM
March 2013
Dr Madan's Slide

33. Dr Madan's Slide

34. Dr Madan's Slide

35. Dr Madan's Slide

36. Dr Madan's Slide

37. Dr Madan's Slide

38. Dr MADAN MOHAN, Consultant ,
Orthopaedics, KIMS TRIVANDRUM
Multiple
Hereditary
Exostosis
Dr Madan's Slide

39. • Characterised abnormal
proliferation of epiphyseal
chondroblasts that cause a
subsequent defect in metaphyseal
remodelling
• AD with 96% penetrance
• Ch no 8,11 and 19
• Malignant transformation?
Dr Madan's Slide

40. Metaphyseal bony prominences
capped with cartilage and
retardation of longitudinal bone
growth
Dr Madan's Slide

41. • 30-60% patients with MHE present with
forearm lesions
• Most of the longitudinal growth of the ulna
occurs in the distal physis
• Ulnar tether
Dr Madan's Slide

42. Dr Madan's Slide

43. Dr Madan's Slide