Objectives

Bone and Joints  

• Fracture

  • Describe the clinical setting and mode of presentation of  fractures

  • What are the radiological findings of fractures

  • What are the common fractures

  • What are the common reasons for fractures?

  • What are the useful imaging modalities in evaluating fractures?

•   Osteomyelitis

  • Describe the clinical setting and mode of presentation of  osteomyelitis

  • What are the radiological findings of osteomyelitis in plain films

  • What are the useful imaging modalities to investigate osteomyelitis? Indicate when you would select each procedure.

  • What are the common etiolgies for osteomyelitris?

• Osteoarthritis

  • Describe the clinical setting and mode of presentation of  osteoarthriis

  • What are the radiological findings of osteoarthritis in plain films

  • What are the useful imaging modalities to investigate osteoarthritis? Indicate when you would select each procedure.

• Rheumatoid arthritis

  • Describe the clinical setting and mode of presentation of  rheumatoid arthritis

  • What are the radiological findings of rheumatoid arthritis in plain films

• Primary bone tumor

  • Describe the clinical setting and mode of presentation of  primary bone tumors

  • What are the radiological findings of primary bone tumor in plain films?

  • What are the useful imaging modalities to investigate primary bone tumors? Indicate when you would select each procedure.

  • What are the common primary bone tumors?

• Secondary bone tumor

  • Describe the clinical setting and mode of presentation of  secondary bone tumors.

  • What are the radiological findings of secondary bone tumors in plain films?

  • What are the useful imaging modalities to investigate secondary bone tumors? Indicate when you would select each procedure.

• Low back pain

  • Describe the clinical setting and mode of presentation of  low back pain

  • What are the common causes for low back pain?

  • What are the useful imaging modalities to investigate low back pain? Indicate when you would select each procedure.

• Bone pain

  •   What are the useful imaging modalities to investigate bone pain? Indicate when you would select each procedure.

  •  What are the common clinical problems presenting as bone pain

• Joint pain

  •   What are the useful imaging modalities to investigate joint pain? Indicate when you would select each procedure.

  •  What are the common causes for joint pain

What are the common clinical conditions requiring imaging procedures in bone and joint diseases?

• Trauma
• Arthritis
• Metastasis
• Primary bone tumors

What are the Imaging procedures useful in evaluation of Joint and bone disorders

• Plain x-ray
• CT
• MRI
• Bone scan
• Arthrogram

What is the utility of  plain x-rays in bone and joint disease?

• Plain x-ray
  • Provides anatomical information
    • fractures 
    • dislocation
    • expanding lesions
  • Alterations of radio density

What is the utility of CT in bone and joint disease?

• CT
  • Precise anatomical information
  • Sensitive than plain x-ray for radio density assessment

What is the utility of MRI in bone and joint disease?

• MRI
  • Precise information about soft tissues
    • ligaments
    • joint capsule
    • cartilages
    • synovial membrane

What is the utility of bone scan in bone and joint disease?

• Nuclear medicine (bone scan): 
  • In a bone scan, radio-labeled isotopes bind preferentially to areas of bone with high turnover rates or increased blood flow.  
  • This makes bone scans useful to detect fracture, infection, tumor, and metabolic bone disease.  
  • However the uptake is non specific
  • One of the most common clinical uses of bone scans is in the case of a patient with a history of cancer with a new complaint of bone or joint pain.  
  • Bone scan is a quick way to evaluate the skeleton for the presence of metastatic disease. 
  • Characteristic patterns of uptake helpful in diagnosis
  • In most cases, though, bone scan is chosen as an imaging modality after other imaging has been negative, but there remains a high clinical suspicion of disease (ie. bone scans have a high sensitivity).

What is the utility of arthrogram in bone and joint disease? When would you consider arthrogram for knee?

• Arthrogarm
  • For precise information about the joint
  • MRI probably will replace the need for arthrogram

What is the recommended sequence of imaging procedures for Bone cases?

• Plain x-ray to start with

Joint Pain   

What are the common causes for monoarticular joint pain? 

• Trauma
• Infection
  • Gonococcal infection is the most common cause of acute joint pain (mono- or oligoarticular), besides trauma, in young adults. 
  • Nongonococcal bacterial infections can be very disabling and destructive. 
    • The most common organisms are S. aureus and S. pneumoniae. 
• Gout
  • 80% of initial gout attacks are monoarticular, and most involve the first metatarsophalangeal joint (great toe; this is called podagra) or the knee. 
• Psedogout
  • Pseudogout is most common in the knee. 
• Also consider Lyme Disease, Reiter’s Syndrome, psoriatic arthritis, early RA, monoarticular OA.
  • The last ones are all less common and should be much lower on the differential. 

What are the common causes for polyarticula joint pain? 

• SLE
• RA
• OA

What are the imaging modalities to investigate joint pain?  Indicate when you would select each procedure. 

• Plain films:  
  • This is usually the first imaging modality to choose in the work-up of joint pain. 
  •   It is important to get two views to thoroughly evaluate the entire joint.  
  • These are especially helpful to evaluate periosteal disease, failure of orthopedic hardware, skeletal deformities, fractures, and degenerative arthritis. 
• Fluoroscopy:  
  • This is helpful to observe joint motion.  
  • It also allows greater visualization of the joint that may help guide needle insertion. 
• CT: 
  • CT is superior to plain films for evaluation of the soft tissues of the joint (see the following explanation). 
  • It is useful to view air-filled spaces, fatty tissue, muscle, and complex bone pathology (especially cortical bone lesions).  
  • CT is superior to MRI for evaluation of soft tissue calcifications and bony abnormalities.  
  • Most importantly, CT is a quicker, cheaper, and easier means to evaluate the joint than MRI, and patients with hardware may not be candidates for MRI.
• MRI:  
  • MRI is useful for visualization of soft tissues, especially to evaluate for changes associated with inflammation, neoplasm, trauma, or ischemia. 
  • MRI is the best means by which to evaluate ligaments and tendons.  
  • It is also superior to plain films to quantify synovial hypertrophy, erosions, and joint edema seen in RA. 

What is the recommended sequence of imaging procedures for arthritis cases?

• Plain x-ray will suffice

Rheumatoid Arthritis 

Describe the clinical setting and mode of presentation of rheumatoid arthritis. 

• Rheumatoid arthritis most commonly presents in women between the ages of 30 and 55, and the onset of disease is usually insidious.  

• Patients are most likely to present with symptoms of pain, stiffness, and swelling of the joints that have persisted for awhile.  

• The arthritis is usually symmetrical, and symptoms may remit occasionally, but typically there is progressive worsening of symptoms over time if left uncontrolled. 

•  Symptoms usually begin in peripheral joints, and spread proximally.  

• The MCP (metacarpophalangeal) and PIP (proximal interphalangeal) joints of the fingers, IP joints of the thumbs and wrists, and MCP joints of the toes are commonly involved early in the disease.  

• Elbows, shoulders, ankles, and knees often become affected in time. 

• Morning stiffness is a common complaint in RA, and it is relatively specific for RA if it lasts for more than one hour.  

• Stiffness typically improves with activity.  

• Concurrent symptoms may include fatigue, myalgia, low-grade fever, weight loss, and depression.  

• Rheumatoid (subcutaneous) nodules may or may not be present.    

Which imaging procedure will you consider for rheumatoid arthritis? 

• Plain films

  • Plain films are especially helpful in rheumatoid arthritis for assessing the patient's response to treatment and to follow the patient's progression over the course of the disease. 

  • It is important to evaluate the patient’s hands (with wrists) and feet radiographically because disease may be limited to the wrists or metatarsophalangeal joints in some patients.      

What are the radiological findings of rheumatoid arthritis in plain films?  Describe the anticipated radiological findings of rheumatoid arthritis of wrist joint

• Synovial changes

  • Disease is most commonly found in the synovial joints.  

  • Soft-tissue swelling may initially cause widening of the joint space due to effusion and periarticular soft-tissue edema. 

• Bone erotions

  • The most common radiographic findings are erosions of cartilage and bone, due to synovial inflammation. 

  • Patients may initially present with erosions in the MCP and PIP joints, and the number of involved joints will increase with time and disease progression. 

• Joint space

  • The inflammatory pannus extends across the articular surface, separating the cartilage from synovial fluid, and leading to cartilage degeneration. 

  • With an increase in size of the synovium and pannus, the subchondral bone may eventually erode. 

  • This ultimately leads to narrowing of the joint space and joint destruction.  

  • Joint destruction occurs rapidly and may appear early in the disease. 

• Ligament changes

  • As ligamentous and tendinous laxity increases, joint alignment may deteriorate, causing deviation, subluxation, and dislocation.

Osteoarthritis: 

When would you consider osteo arthritis as the etiology for joint pain? 

• Patients commonly present with joint pain, which is exacerbated by activity and relieved by rest.   

• Other symptoms that patients present with are morning stiffness resolving <30-60min after wakening (different from Rheumatoid Arthritis which lasts longer)

•  “Gelling” - recurrence of stiffness following period of inactivity

What are the most common mode of clinical presentations of Osteo arthritis?

• Polyarticular OA in middle age/elderly women (most common presentation) involving the DIP and PIP hand joints, the first carpometacarpal joint, the knees, hips and spine.

• Monoarticular OA in young adults (due to congenital abnormality or prior trauma)

• Pauciarticular OA in middle age adults in large weight bearing joints (i.e. spine, hip)

What are the physical exam findings of Osteoarthritis?

On physical exam several signs are notable.

• Tenderness to palpation of involved joints

• Crepitus

• Bony Enlargement:  

  • Heberden Node (bony enlargement of DIPs)

  • Bouchard Nodes (bony enlargement of PIP)

• Decreased ROM 

What are the radiologic findings of osteoarthritis in plain films? 

• Joint space narrowing (from loss of cartilage)– asymmetrical, may be only finding in early disease

• Subchondral bone sclerosis – increased bone density

• Subcondral cysts

• Osteophytes (bone spurs)

• Central bone erosions – occur in small interphalangeal joints of fingers (unlike rheumatoid arthritis)

What are the other useful imaging modalities to investigate osteoarthritis? 

• Plain films 

  • Plain radiographs are the most useful form of imaging, although not necessarily the most sensitive.

  • The radiographic appearances are diagnostic of OA, therefore, other forms of imaging are seldom necessary. 

• Radionuclide Scanning 

  • Radionuclide scanning shows increased activity during the bone phase in the subarticular region of any affected joint.  

  • These changes are apparent years before the typical radiographic changes appear and reflect the vascular reaction and osteoblastic activity that are present even in the early stages of cartilage loss. 

• Computed Tomography and Magnetic Resonance Imaging 

  • CT and MRI although capable of detecting early osteoarthritic changes in the joint, are seldom used in the routine assessment. 

  • Their practical value lies in showing other abnormalities associated with osteoarthritis, in imaging sites that are inaccessible to plain radiography, and in excluding disorders such as osteonecrosis, pigmented villonodular synovitis, or synovial chondromatosis in the differential diagnosis. 

Describe the radiological findings of osteo-arthritis knee

Bone pain

What are the common clinical problems presenting as focal bone pain?   

• Stress Fracture or Trauma

• Infection

• Malignancy

• Paget’s Disease

• Osteoid osteoma  

What are the common clinical problems presenting as diffuse bone pain?   

• Malignancy
• Paget’s Disease
• Osteomalacia
• Osteoporosis
• Metabolic Bone Disease

Secondary Bone Tumors

Describe the clinical setting and mode of presentation of secondary bone tumors?

• There are several clinical settings in which metastatic tumors of the bone arise. 

  • A lesion may be found in asymptomatic patient (commonly with a history of primary tumors). 

  • A patient with a known primary tumor may also be seen with a painful lesion (i.e. in the spine or extremities). 

    • The pain often occurs gradually over weeks, is localized, and worse at night. 

    • A patient may present with a pathologic fracture – a fracture occurring in an area of bone weakened by cancer.  

    • Also, patients may present with nerve root or spinal cord compression syndromes.   

  • Occasionally, patients may present with similar complaints of pain without known primary cancer and be found to have metastatic bone cancer. 

What are the common primaries metastasising to bones?

These forms of cancer usually affect older people.   

• Prostate (most common site from men)

• Breast (most common site from women)

• Lung

• Kidney

• Bladder

• Thyroid

• Lymphomas

Which are the common metastatic sites of bone lesions?

• Vetebrae

• Proximal femur

• Pelvis

• Ribs

• Sternum

• Proximal humerus

• Skull

What are the useful imaging modalities to investigate secondary bone tumor?           

• Plain Films: 

  • Indicates the net result of bone resorption and repair showing osteoblastic, osteolytic and mixed lesions, as well as defining the bone anatomy. 

  • Remember that lytic lesions must be greater than 1cm in diameter in order to be detected. 

  • A skeletal survey (includes lateral skull, cervical spine, anteroposterior (AP) and lateral thoracic and lumbar spine, an AP pelvis and chest radiograph) is used as the primary investigation for bone metastases in multiple myeloma. 

• Radioisotope Bone Scan:  reflects the metabolic reaction of bone to the disease process, with preferential uptake of the tracer at sites of active bone formation.

  • More sensitive than plain films for detecting metastasis.  

  • Excellent screening modality.

  • No bone anatomy detected except in areas of increase uptake.   

  • Metastases are usually multiple, irregularly distributed foci of tracer that do not correspond to any single anatomic structure. 

•  CT:  excellent soft tissue image, soft tissue and bony metastases are clearly demonstrated.

  •  CT most appropriate for diagnosing spinal metastases in locations difficult to assess with bone scan or radiographs (i.e. pelvis/sacrum).

  • Also, it is reserved for patients with positive bone scans and negative radiographs in order to clarify pathology. 

• MRI:  even more sensitive, especially for lesions involving the spine, because it can provide mutiplanar images and identify the nerve and spinal roots.

  •  Also used with positive bone scan and normal radiographs, as well as, vertebral compression fractures, and bone marrow infiltration of metastases.      

Which imaging procedure will you consider for suspected bone metastasis? What is the recommended sequence of imaging procedures for suspected metastases?

Depends on the mode of clinical presentation of metastatic bone tumor

• A lesion may be found in asymptomatic patient (commonly with a history of primary tumors). 

  • Bone scan

  • Plain x-ray or CT

• A patient with a known primary tumor may also be seen with a painful lesion (i.e. in the spine or extremities). 

  • A patient may present with a pathologic fracture – a fracture occurring in an area of bone weakened by cancer.  

    • Plain x-ray

  • Also, patients may present with nerve root or spinal cord compression syndromes.   

    • MRI 

• Occasionally, patients may present with similar complaints of pain without known primary cancer and be found to have metastatic bone cancer. 

  • Plain x-ray

  • Bone scan

What are the radiological findings of secondary bone tumors in plain films? 

• Osteoblastic 

  • lesions: result from tumor producing cytokines that activate osteoblasts.

  • best detected on Bone Scan

  • most commonly arises from prostate cancer, but also arise from breast, lung and carcinoid

• Osteolytic 

  • lesions:  result from the tumor production of substances (i.e.PTHrP, Vit D-like steroids) that elicit bone resorption

  • best detected by plain radiology (may not be apparent until ³ 1cm)

  • most commonly arises from breast, lung, thyroid, renal, melanoma, and gastrointestinal malignancies

• Mixed lesions –mixture of osteoblastic and osteolytic lesions – seen in breast cancer.   

Primary Bone Tumor

What are the common primary bone tumors?

• Primary bone tumors are rare, accounting for less than 1% of all malignant tumors.  

• The most common benign bone tumor is osteochondroma and occur most often in people between the ages of 10 and 20.  

• Malignant primary bone tumors include 

  • Osteosarcomas

  • Ewing’s sarcoma

  • Fibrosarcoma

  • Chondrosarcoma

Describe the clinical setting and mode of presentation of primary bone tumors.

• Primary bone tumors are uncommon malignancies, but they are an important cause of cancer morbidity and mortality, especially among young people. 
• Although relatively rare in childhood (metastatic tumors involving the skeleton are more common), primary bone tumors represent the sixth most common neoplasm in children, while in adolescents and young adults, they are the third most frequent, exceeded only by leukemias and lymphomas.  
• The majority of patients with a primary bone tumor present with localized pain and/or swelling. 
• The first diagnostic test to arouse suspicion for a primary bone tumor is generally a plain radiograph  of the affected area. 
• Depending upon the clinical history and the degree  of suspicion, a staging workup may then be instituted, or a diagnostic biopsy considered. 

• Plain radiographs

  • Chondrosarcoma is a fusiform, lucent defect with scalloping of the inner cortex and periosteal reaction. 

  • Extension into the soft tissue may be present as well as punctate or stippled calcification of the cartilage matrix. 

• CT

  • is helpful in defining the integrity of the cortex and distribution of calcification.

• MRI 

  • is invaluable in surgical planning as it demonstrates the intraosseus and soft tissue involvement of the tumor. 

  • MRI is also helpful in evaluating possible malignant degeneration of osteochondromas by allowing accurate measurements of the cartilage cap.

What are the useful imaging modalities to investigate primary bone tumors?  Indicate when you would select each procedure.

• Although plain radiographs can often predict the probable histology of a potentially malignant bone lesion, the definition of tumor size and local intraosseous and extraosseous extent is most accurately achieved by magnetic resonance imaging (MRI).
• The entire involved bone should be imaged to avoid missing skip metastases.
• CT scans are generally less useful than MRI for assessing primary bone tumors; however, they may be preferred over MRI for recognizing destruction of flat bones, such as the scapula, pelvis, or the posterior vertebral elements. 
• CT is also the best method to evaluate the thorax for metastatic disease.
• Radionuclide bone scanning is the preferred method for evaluating the entire skeleton for the presence of multiple lesions.
• Although the isotope scan is more sensitive than plain radiography, some metastases may be missed.
• The addition of single photon tomography (SPECT) may improve sensitivity.
• Bone scans are also limited by a lack of specificity, with most false-positive results due to trauma, whether recalled by the patient or not.
• As a result, the diagnosis of metastatic bone disease usually requires radiographic confirmation, especially if the number of lesions is small (fewer than four) and/or limited to the ribs.
• The probability that an abnormal scan represents metastatic tumor is directly related to the number of abnormal foci.
• Although whole body MRI has the potential to detect more lesions in the axial skeleton (particularly the spine) than bone scan, it is generally not feasible in most centers due to time constraints. 
• Whole body MRI techniques are rapidly advancing, and may replace technetium bone scanning in the future.  
• There is no consensus as to the utility of PET scans in the clinical evaluation of bone metastases. 
• For some malignancies (ie, lung and breast cancer), PET scans appear to be more specific than bone scans, although they are possibly less sensitive (especially for osteoblastic foci), and clearly more expensive. In patients with primary bone tumors, at least one study suggests that PET scans are inferior to bone scans for detecting osseous metastases from osteosarcoma.

• A diagnostic bone biopsy is indicated in the following circumstances:
• Whenever there is significant doubt as to thediagnosis of a benign or malignant lesion 
• When the histologic distinction among possible diagnoses could alter the planned course of treatment 
• When definitive confirmation of the diagnosis is  required before undertaking a hazardous, costly, or potentially disfiguring treatment

Trauma

What are the common clinical problems of Bones and joints following trauma?

• Fractures

• Soft tissue injuries

  • Capsular tear

  • Tear of cartilage

  • Tear of ligaments

• Dislocation

What are the common fractures following trauma?

What are the common soft tissue injuries following trauma?

What are the common dislocations following trauma?

When would you suspect fracture following trauma?

When would you suspect soft tissue injuries of joints following trauma?

When would you suspect dislocation following trauma?

What are the imaging procedure of choice to evaluate bone and joint injuries due to trauma?

• Plain films

• CT

• MRI

What is the recommended sequence of imaging procedures for trauma cases?

• Trauma (based on need and the problem)
  • Expected bone changes
    • Plain x-ray
    • CT 
  • Expected soft tissue injuries
    • MRI 

What is the recommended sequence of imaging procedures for fracture cases?

• For cases with suspected  bone changes
  • Plain x-ray first
  • CT 

What is the recommended sequence of imaging procedures for soft tissue injury cases?

• For cases with suspected soft tissue injuries
  • MRI 

When will you suspect stress fracture?

What are the useful imaging modalities to investigate stress fracture pain?

• Plain Films 

  • primary method to evaluate 

  • usually not positive until 2 wks after onset of pain with periosteal proliferation. 

• Bone Scintigraphy 

  • may be useful in patients with negative radiographic stress related injuries.

• MRI 

  • multiplanar capability and superb soft tissue contrast.  

  • becoming method of choice in foot and ankle pain evaluation, especially relating to tendon and ligament injuries.  

Which imaging procedure will you consider for suspected ACL tear?

Describe the radiological findings of ACL tear.

Describe the radiological findings of medial semilunar cartilage tear on MRI.