Fixation evaluation, fracture disease, and fracture healing Flashcards

1
Q

What are the 4 “A’s” of radiographic evaluation when reviewing post-op or recheck radiographs of a fracture repair?

A

Apposition

Alignment

Apparatus

Activity

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2
Q

What are you looking for when assessing apposition on post-op or re-check radiographs?

A
  • Are the fracture edges touching?
  • Only very important in articular fractures
    • Not important in biological osteosynthesis
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3
Q

What are you looking for when assessing the activity level in post-op or re-check rads?

A
  • Is there evidence of:
    • Bone healing–callus spanning across fracture
    • Infection–more lucency, too much periosteal activity
    • Osteopenia
    • Malunion
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4
Q

Other than obvious implant migration, what is a radiographic change that would be indicative of implant loosening?

A

Radiolucency around screw heads

ALWAYS compare to original radiographs!

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5
Q

What radiographic changes are consistent with osteomyelitis?

A

Proliferative/lytic appearance

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6
Q

What are the 2 types of non-union?

A
  • Viable = biologically active fracture with cartilage and fibrous tissue between fracture ends
  • Non-viable = fracture ends are sclerotic with rounded bone edges and visible fracture gap
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7
Q

What is the recommended treatment for non-union fractures?

A

Appropriate stabilization and cancellous bone autographs

Partial mandibulectomy is an option for treatment of chronic non-union of the mandible

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8
Q

What is the pathogenesis of quadriceps contracture?

A
  • Muscle fibers are replaced by fibrous tissue
  • Adhesions form between muscle and bone
  • Changes result in severe decrease in limb motility
  • Periarticular fibrosis/joint ankylosis/DJD further inhibits limb function
  • Often irreversible
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9
Q

What are the risk factors associated with quadriceps contracture?

A
  • Distal femoral fractures
  • Young patients (< 6mo)
  • Prolonged immobilization
  • Extensive muscle/ST trauma
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10
Q

What treatment options are available for quadriceps contracture?

A

Rehabilitation (ROM exercises + NSAIDs) to prevent muscle atrophy and scar tissue

Treatment is rarely successful

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11
Q

T/F: The prognosis for quadriceps contracture (with treatment) is poor for full function and guarded for partial function

A

TRUE

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12
Q

What other morbidity is associated with overly rigid fixation and limb immobilization for treatment of a fracture?

A

Disuse osteoporosis

Muscle atrophy

Ligamentous laxity

Also: cartilage atrophy, digital flexor contracture, and fracture-associated sarcoma

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13
Q

What is the difference between disuse osteoporosis and muscle atrophy?

A
  • Disuse osteoporosis
    • Decrease in stress application to the bone –> increased osteoclast activity
    • Can occur with casts and excessively strong implants/fixators
  • Muscle atrophy
    • Secondary to disuse or immobilization
    • Reversible
      • Can take significant time to return to normal
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14
Q

What is ligamentous laxity?

A
  • Associated with muscle atrophy from disuse or immobilization
  • Loose ligaments result in joint instability
  • Should resolve with improved muscle tone
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15
Q

What radiographic changes are expected for an aggressive, neoplastic bone lesion?

A
  • Cortical lysis
  • Periosteal reaction
  • +/- mineralization of surrounding soft tissues
  • Loss of trabecular pattern
  • Lack of distinct border between normal and abnormal bone
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16
Q

What are some differential diagnoses to keep in mind when observing radiographic changes due to an aggressive, neoplastic bone lesion?

A
  • Osteomyelitis
  • Osteosarcoma
  • Bacterial, fungal infections
  • CSA, FSA, HSA
  • Lymphoma
  • Bone cyst
17
Q

Which osteosarcoma treatment option is associated with the longest MST?

A

Limb-sparing surgery–local removal of tumor with wide margins and the bone is replaced with graft, prosthesis or regenerated via bone transport osteogensis

18
Q

What is the purpose of amputation of a limb affected with osteosarcoma if there is no change in MST?

A

Removes the source of pain, especially in cases of pathological fracture

19
Q

What are the most common sites for metastasis of osteosarcomas?

A

Lungs, local LN, other bones

(Usually located towards the elbow and away from the knee)

20
Q

What staging is recommended with osteosarcomas?

A
  • 3 view thoracic rads or thoracic CT
    • CT >>> rads when diagnosing pulmonary metastasis
  • Aspiration of any enlarged LN
  • CBC/chemistry/UA
    • Increased ALKP is assoc. w/ poorer prognosis
21
Q

T/F: Micrometastases are present in most patients at time of initial diagnosis

A

TRUE

22
Q

What is the gold standard for obtaining a diagnosis of a bone lesion?

A

Biopsy

23
Q

What bone tumor locations are amenable to treatment by limb-sparing?

A

Distal radial lesions have the best outcome

24
Q

Other than osteosarcomas, what primary bone tumors are diagnosed in small animal patients?

A

Chondrosarcoma, fibrosarcoma, hemangiosarcoma

25
Q

What tumor types are specific to the digits?

A
  • Dogs
    • Squamous cell carcinoma and melanoma
  • Cats
    • Squamous cell carcinoma, fibrosarcoma, adenocarcinoma, osteosarcoma, hemangiosarcoma