There are numerous categories of pathology in the evaluation of skeletal disease. Developmental and congenital disordersInflammatorySkeletal dysplasiasTraumatic Neoplastic Metabolic disordersVascular disordersMiscellaneous. Pathological Classification. Developmental
1. Image Evaluation Upper Limb
3. Pathological Classification Developmental – Significant deviation from the norm resulting from a congenital or hereditary defect. E.g. Achondroplasia
Inflammatory – Disorders resulting from a inflammatory origin. E.g. Rheumatoid
Skeletal dysplasias – Dysplasia (Latin for “Bad Form”), abnormalities of skeletal growth and strength, e.g Osteopetrosis
Traumatic – Physical Injury
Neoplastic – Tumours benign and Malignant.
Metabolic – Resulting from biochemical processes e.g Rickets, Fluorosis
Vascular – Originating from a blood disorder and causing bony changes, e.g Thalassemia
Miscellaneous – Others which don’t easily fit any other category, e.g joint infections and arthritis
4. Today Osteoarthritis
Fractures of the wrist
Elbow – Fat pad sign or ‘sail sign’
Skeletal Dysplasia - Osteopetrosis
5. Degenerative Joint Disease – Many varieties and causes Osteoarthritis
Diffuse idiopathic skeletal hyperostosis
Juvenile chronic arthritis
7. Markers of Osteoarthritis Non-uniform joint space narrowing.
Subchondral sclerosis (sclerosis – dense white appearance radiographically, corresponding with overgrowth of bone).
Subchondral cyst formation
Subluxation (partial dislocation), deformity, malalignment.
10. Osteoarthritis – degenerative disease
13. Frequently encountered fracture types
14. Torus or buckle fracture
15. Colles’ fracture Mechanism – dorsiflexion.
Fracture of the distal portion of the radius with dorsal displacement.
Appearance referred to as the “dinner fork deformity”.
16. Smith’s fracture Reverse colles’ fracture.
Mechanism – variable.
Fracture of distal portion of radius with palmer displacement.
Less common than Colles’ fracture.
17. Fat pad sign – intracapsular fat pad displacement
18. Fat pad sign – intracapsular fat pad displacement Fat pads are anterior and posterior.
Fat pad performs a triangular lucency anterior to the distal humerus.
Intracapsular fat pad displacement indicates a joint effusion.
This sign usually indicates the existence of intracapsular fluid or blood and is often indicative of a fracture – not always well seen!
20. In the absence of and obvious fracture, this sign very often will indicate the presence of a fracture of the Radial head that is not easily seen with standard projections, and additional objections should be performed in this case in an attempt to exclude fracture.
Need a true lateral projection in order to visualise the fat pad. Obliquity of the humerus will hid the fat pad!
21. Chisel Fracture
22. Skeletal Dysplasias
23. Skeletal Dysplasias - Osteopetrosis Is a rare hereditary bone disorder – may also be called marble bone disease.
May be benign or malignant!
Patterns off diffuse osteosclerosis.
This bone, while dense, is very brittle, fragile and fractures easily.
24. Osteopetrosis Normal
25. Tumour – Radiographic appearances Osteolytic lesion in the metaphyseal portion or the distal radius.
Extension into the subchondral region.
Tumour extension to the cortical rim.
“eggshell” cortical rim still intact.
Mild bony expansion
No obvious extension into the soft tissues
26. Giant Cell Tumour Usually affect the metaphyseal portion of long bones.
10% are malignant.
Most occur in the distal radius, distal femur and proximal tibia and humerus.
Typical age at onset – 30-50yrs.
Giant cell tumours of the distal radius are more likely malignant than at any other site.
28. Ouch! Amputation at the wrist in an industrial accident
29. Terminology Sclerosis – extra bony growth
Subchondral – area of bone under the articular cartilage
Cyst – fluid filled
Osteophyte – extra bone growth to strengthen area of weakness
Osteopetrosis – sclerosing skeletal dysplasia
Chisel fracture – a form of radial head fracture
Torus or buckle fracture
Fat pad sign
Colles fracture – angulation of fracture fragment posteriorly (dinner fork deformity)
Smiths fracture – angulation of fracture fragment anteriorly
Radiolucent – radiographically lacking density
Osteosclerotic – Bone forming
Osteolytic – Bone destroying
Dysplasia – bad growth
30. Homework Monteggia’s Fracture – dislocation (Forearm)
Galeazzi’s Fracture – dislocation (Forearm)
Bennett’s Fracture – (Thumb)
Eisenberg, R.L. & Johnson, N.M. Comprehensive Radiographic Pathology. Mosby. 2003.
Taylor, J. & Resnick, D. Skeletal Imaging of the spine and extremities, Saunders.
McKinnis, L.N. 1997, Radiographic evaluation of normal versus pathologic bone. In Fundamentals of orthopaedic radiology, F.A. Davis Company, Philadelphia, pp 30-70