1.Stress fracture 2.spondylolisthesis 3.Avulsion fracture 4.Pathological fracture 5.Myositis ossificans 6.Compartment syndrome

1. SPECIAL TYPES OF
TRAUMA

2.  A stress fracture refers to a fracture occurring
in bone due to a mismatch of bone strength and
chronic mechanical stress placed upon the bone.
1.STRESS FRACTURE

3. It can either be:
 fatigue fracture - abnormal stresses on normal
bone
 insufficiency fracture - normal stresses on
abnormal bone

4. LOCATION
 March fracture
 Mid and distal tibia
 Proximal fibula

5. RADIOLOGICAL FEATURES
Plain film
Osteal bone
 endosteal or periosteal callus formation without
fracture line
 circumferential periosteal reaction with fracture line
through one cortex
 frank fracture

6. Cancellous bone
 flake-like patches of new bone formation (2-3 weeks)
 cloudlike area of mineralized bone
 focal linear area of sclerosis, perpendicular to the
trabeculae

7.  A 42-year old female who
walks long distances and
has been experiencing
forefoot pain for a month.
On the initial radiograph
no fracture is seen.
After 4 weeks, a follow up
radiograph clearly marks
callus formation at the
site of the stress fracture.

8. MRI
has surpassed bone scintigraphy as the imaging
tool for stress fractures
 sensitivity (100%)
 specificity (85%)

9. Grading is based on signs seen at MRI:
1. mild - moderate periosteal edema on STIR, no
marrow changes
2. moderate - severe periosteal edema on STIR +
marrow changes on T2WI
3. + marrow changes on T1WI
4. fracture line visible

10.  A 22-year old female, a
professional athlete with a
recent onset of forefoot pain,
persisting after training.
At presentation MRI showed
a high signal on the STIR-
and a low signal on T1WI
(i.e. grade 3 stress
fracture).

11.  A 27-year old soccer player
in the highest league of
amateur football.
He suffered from midfoot
pain with a recent increase
in complaints.
T1WI shows a definite
fracture line in the
navicular bone, indicating
a grade 4 stress fracture.
Corresponding CT shows a
fracture line and sclerosis
on the axial images and
coronal reconstructions.

13. 2.SPONDYLOLISTHESIS
 forward displacement of a vertebra
anterolisthesis relative to the segment below,
typically due to spondylolysis (pars interarticularis
defects).
 Most frequent at L5/S1 and to a lesser degree L4/5
articularis defects).

14.  grade I: 0-25%
 grade II: 25-50%
 grade III: 50-75%
 grade IV: 75-100%
 spondyloptosis: >100%

16. 3.AVULSION FRACTURE
 result when the fracture fragment is pulled from
its parent bone by forceful contraction of a
tendon or ligament
 Young adults(M:F= 2:1)
 In the pelvis, the newly formed secondary centers
of ossification, the apophysis, are the most likely
portions of the bone to avulse

17. ??

18. IMAGING FINDINGS
 Conventional
radiography is the
study of first choice
 avulsed bony
fragment usually
immediately adjacent
to the parent bone

20. SITES OF AVULSION FX WITH
MUSCLE ORIGIN
Site of avulsion fracture Muscle origin
Anterior superior iliac spine Sartorius
Anterior inferior iliac spine Rectus femoris
Ischial tuberosity Hamstrings
Greater trochanter Gluteals
Posterior calcaneus Achelles tendon
Olecranon process Triceps
Superior patella Quadriceps
Inferior patella Patella ligament
Tibial tuberosity Patella ligament

21. OSGOOD-SCHLATTER DISEASE
 Lateral view x-ray of the knee
demonstrating
fragmentation of the tibial
tubercle with overlying soft
tissue swelling.

22. SINDIG-LARSEN DISEASE

23. 4.PATHOLOGICAL FRACTURE
A fracture that occurs through bone which was
previously abnormal
• metastatic lesion
• multiple myeloma
• enchondroma
• unicameral bone cysts

24. IMAGING FINDINGS
 Fracture line extending through a destructive
lesion in the bone
Usually transverse in direction
 Surrounding bone may demonstrate
Endosteal scalloping
Cortical destruction
 Frequently associated with a soft tissue mass

27. DRILLER’S DISEASE(VIBRATION
SYNDROME)
 Workers using vibration machinery
 >5 years of use
 Degenerative cysts found in the bones of wrist

29.  Avascular Necrosis of the
Scaphoid. Frontal view of the
wrist shows increased density
and partial collapse of the
proximal pole of the scaphoid
(blue arrow) secondary to a
fracture of the waist of the
scaphoid (red arrow).
The smooth and sclerotic
margins of the fracture line
suggest non-union of the
fracture and there is increased
distance between the scaphoid
and the lunate suggesting
disruption of the scapholunate
ligaments. .

30.  Frontal view of the hand and
wrist demonstrates sclerosis,
irregularity
and collapse of the lunate
(blue arrows) in Kienbock's
Disease

31.  Frieberg’s disease

32. 5.MYOSITIS OSSIFICANS
a benign process characterized by heterotopic
ossification usually within large muscles.
 Trauma
 Paraplegia(hip and knee joint )
 Ligamentous avulsion or chronic ligamentous
trauma

33. Plain film
 Calcification (2-6 weeks)
 well circumscribed peripherally calcified
appearance(2 months).
 Cleft between it an the subjacent bone may be
difficult to see on plain films(string sign)

36. CT
Mineralization proceeding from the outer margins
towards the centre.
String sign
The peripheral rim of mineralization (4-6week)

38. MRI
Early changes:.
T1
 ill-defined isointense to muscle mass
T2
 periphery: high signal (oedema) seen up to 8 weeks
 central: heterogeneous
T1 C+ (Gd): enhancement is often present

39. Late appearances mimic bone
T1
 periphery: low signal (mature lamellar bone)
 central: intermediate to high signal (bone marrow)
T2
 periphery: low signal (mature lamellar bone)
 central: intermediate to high signal (bone marrow)
T1 C+ (Gd): usually none in mature lesions.

42.  Pellegrini-Stieda lesions
are ossified post-
traumatic lesions at (or
near) the medial
femoral collateral
ligament adjacent to the
margin of the medial
femoral condyle. One
presumed mechanism of
injury is a Stieda fracture
(avulsion injury of the
medial collateral ligament
at the medial femoral
condyle).

43. DD’S
Parosteal osteosarcoma: calcifies in centre and
continues towards the periphery
Malignant fibrous histiocytoma
Synovial sarcoma

45. 6.COMPARTMENT SYNDROME
 Limb-threatening and life-threatening condition
observed when perfusion pressure falls below tissue
pressure in a closed anatomic space.
 Compartment syndrome progresses to
rhabdomyolysis if untreated
 Fasciotomy

46.  T1W-images of a patient
one month post trauma.
On the post-Gadolinium
image the necrosis in
the anterior and
lateral compartment
is seen.
The posterior
compartment is normal.

47.  T2W-image of a
patient with a chronic
lateral compartment
syndrome.

48. THANK YOU