From the Guidelines
A bone scanogram is not typically used to evaluate leg length discrepancy.
Role of Bone Scanogram
- Bone scanograms are more commonly used to assess bone metabolism, detect fractures, or evaluate bone infections, rather than measuring leg length discrepancy 1.
- In the context of total knee arthroplasty, bone scans may be used to assess periprosthetic activity, but they are not typically used to evaluate leg length discrepancy 1.
Alternative Imaging Modalities
- Radiographs, including standing anteroposterior (AP) and lateral views, are often used to evaluate leg length discrepancy and assess alignment of the lower extremity 1.
- Full-length standing radiographs, also known as scanograms, can be used to measure leg length discrepancy, but this is typically done using radiographs, not bone scans 1.
Clinical Considerations
- The use of bone scans to evaluate leg length discrepancy is not supported by the evidence, and alternative imaging modalities, such as radiographs, are preferred 1.
- Clinicians should exercise caution when interpreting bone scan results, as they may not provide accurate information on leg length discrepancy 1.
From the Research
Role of Bone Scanogram in Evaluating Leg Length Discrepancy
- A bone scanogram, particularly a CT scanogram, is a valuable tool in evaluating leg length discrepancy, as it provides accurate measurements of limb length [ 2, 3,4,5 ].
- The use of CT scanograms allows for the assessment of limb flexion, which may be missed on a single frontal projection, and provides lateral views of the limbs without requiring a change in patient position [ 2 ].
- CT scanograms have been found to be more accurate than conventional orthoroentgenograms in determining bone length discrepancies 3.
- The efficacy of routine postoperative CT scanograms in evaluating limb length discrepancy has been demonstrated in patients with comminuted femoral shaft fractures treated with intramedullary nailing 4.
- While CT scanograms are reliable and accurate, other modalities such as EOS low-dose radiography may offer advantages in terms of radiation exposure and accuracy 6.
Advantages and Limitations of Bone Scanograms
- Advantages of bone scanograms include:
- Accurate measurements of limb length
- Ability to assess limb flexion
- Lateral views of the limbs can be obtained without changing patient position
- Limitations of bone scanograms include:
- Radiation exposure
- May not be as comprehensive as other assessment techniques, such as full-length standing AP computed radiographs (teleoroentgenograms) 5.