What is involved in a proper complete diagnosis of a fracture?

Proper Complete Diagnosis of Fracture

Begin with standard radiography (X-ray) of the affected area in two orthogonal views as the mandatory first-line imaging study for any suspected fracture, followed by MRI without IV contrast if radiographs are negative but clinical suspicion remains high. 1

Initial Imaging Approach

Standard Radiography (X-rays)

• Obtain at minimum two views (anteroposterior and lateral) of the area of interest as the initial diagnostic test for all suspected fractures. 1, 2
• For rib fractures specifically, a standard posteroanterior chest radiograph should be performed first, though it may miss up to 50% of rib fractures. 2
• For hip fractures, obtain AP pelvis and cross-table lateral hip views as the initial imaging of choice. 3
• Repeat radiographs in 10-14 days can increase sensitivity if initial films are negative but clinical suspicion persists, though this delays diagnosis. 1

Critical Limitation to Recognize

• Approximately 10% of proximal femoral fractures and up to 50% of rib fractures are not identified on initial radiographs, making advanced imaging essential when clinical suspicion remains high despite negative X-rays. 2, 3

Advanced Imaging When Radiographs Are Negative

MRI Without IV Contrast (Preferred Next Step)

• MRI without IV contrast is the gold standard for definitive diagnosis when radiographs are negative but clinical suspicion remains high, with excellent sensitivity for detecting radiographically occult fractures. 1, 4
• MRI should be performed urgently for suspected hip/femoral neck fractures due to high risk of complications including osteonecrosis and progression to complete fracture. 1
• MRI demonstrates linear T1 and T2 hypointense signal representing fracture lines, and T1 hypointense with T2 hyperintense signal in surrounding bone marrow edema. 1

CT Without IV Contrast (Alternative or Complementary)

• CT is less sensitive than MRI but remains a reasonable alternative when MRI is contraindicated or unavailable. 1
• CT is particularly useful for detecting articular surface collapse, sclerosis indicating secondary necrosis, and visualizing fracture patterns difficult to see on plain radiographs. 1, 4
• Consider CT when pathologic fracture is suspected (may indicate underlying malignancy) or when multiple fractures are suspected in high-risk patients (elderly, long-term steroid therapy). 2

Tc-99m Bone Scan with SPECT

• Bone scintigraphy is complementary or adjunctive, not an alternative to skeletal survey. 1
• Use when radiographic skeletal survey is negative but clinical suspicion remains high and further evidence of skeletal trauma is warranted. 1
• Particularly good for detecting periosteal reaction and rib, spine, pelvic, and acromion fractures. 1
• Major limitation: Cannot accurately date fractures and may remain positive for up to 1-3 years after injury. 1, 2

Essential Clinical Assessment Components

History and Physical Examination Details

• Document mechanism of injury to differentiate traumatic from pathologic fractures (pathologic fractures occur without adequate trauma). 5, 6
• Assess for inability to ambulate, limb deformity (shortened and externally rotated in hip fractures), and severe pain on movement. 3
• Perform thorough neurovascular examination searching for peripheral nerve injury and vascular injury before any immobilization. 7
• Identify risk factors: osteoporosis, bisphosphonate therapy, malignancy, long-term steroid use, pregnancy. 1, 4

Laboratory Evaluation

• Obtain full blood count, clotting studies, renal function to rule out secondary contributors to osteoporosis and guide treatment planning. 3, 8
• Consider biochemical markers for fracture healing assessment in complex cases. 9

Radiological Assessment for Vertebral Fractures

• Perform dedicated vertebral imaging when osteoporosis or pathologic fracture is suspected. 8

Special Clinical Scenarios

Stress Fractures (Fatigue/Insufficiency)

• Initial radiographs are mandatory but have low sensitivity early in the disease process. 1
• If radiographs are negative and clinical suspicion is high, proceed directly to MRI without IV contrast rather than waiting 10-14 days for repeat radiographs. 1
• For high-risk locations (femoral neck, sacrum), MRI should be used preferentially even as first-line imaging after initial radiographs. 1

Pregnant Patients

• Radiographs remain the initial imaging evaluation because findings may be conclusive and fetal absorbed dose is minimal (<1 mGy for extremity imaging). 1
• MRI without IV contrast should be performed as necessary to make the diagnosis, as it does not use ionizing radiation. 1
• For pelvis/hip concerns, the approximate mean fetal absorbed dose from pelvis radiograph is 1.1 mGy, from pelvis CT is 25 mGy, and from bone scintigraphy is 4.6 mGy (early pregnancy). 1

Suspected Pathologic Fractures

• Pathologic fractures require histological diagnosis to ensure adequate therapy, as they result from preexistent pathological bone lesions (tumors, metastases, cysts, osteoporosis). 5, 6
• Consider chest CT without IV contrast when pathologic fracture is suspected to evaluate for underlying malignancy. 2
• Tc-99m bone scan may be appropriate as complementary study when pathologic fracture is suspected. 2

Pediatric Physical Abuse Evaluation

• Skeletal survey should include frontal and lateral skull views, lateral cervical and thoracolumbosacral spine, single frontal views of long bones, hands, feet, chest, and abdomen, plus oblique rib views. 1
• Images must be obtained using high-detail systems and coned to specific areas of interest. 1
• Repeat skeletal survey approximately 2 weeks after initial examination can provide additional information in up to 12% of children. 1

Common Pitfalls to Avoid

• Never rely on physical examination alone to diagnose or exclude fractures—imaging is essential. 3
• Avoid inadequate radiography with only single views; two orthogonal views are almost always needed. 7
• Do not delay MRI when clinical suspicion is high for hip/femoral neck fractures, as delays increase mortality, complications, and length of stay. 3
• Avoid overutilization of CT for uncomplicated isolated fractures, as increased detection rarely changes management. 2
• Do not neglect evaluation for complications (pneumothorax, hemothorax, pulmonary contusion, vascular injury) that may have greater clinical significance than the fractures themselves. 2, 7
• Never apply immobilization before thorough neurovascular examination. 7
• Avoid prolonged immobilization which can result in joint stiffness or disability. 7

Determining Fracture Healing and Complications

Follow-up Imaging

• Most fractures are followed clinically until pain-free, then activity is increased in controlled manner. 1
• For persistent pain after adequate conservative management, perform MRI to evaluate for complications including osteonecrosis, delayed healing, or misdiagnosis. 1, 4
• CT is useful for identifying possible etiologies in delayed healing such as osteoid osteoma or suspected completion of fracture. 1
• Clinical examination combined with available imaging modalities helps judge progression of healing with confidence. 9