Methods for assessing leg length discrepancy
- Sabharwal, S. and Kumar, A.
- UNLABELLED: The use of accurate and reliable clinical and imaging modalities for quantifying leg-length discrepancy (LLD) is vital for planning appropriate treatment. While there are several methods for assessing LLD, we questioned how these compared. We therefore evaluated the reliability and accuracy of the different methods and explored the advantages and limitations of each method. Based on a systematic literature search, we identified 42 articles dealing with various assessment tools for measuring LLD. Clinical methods such as use of a tape measure and standing blocks were noted as useful screening tools, but not as accurate as imaging modalities. While several studies noted that the scanogram provided reliable measurements with minimal magnification, a full-length standing AP computed radiograph (teleoroentgenogram) is a more comprehensive assessment technique, with similar costs at less radiation exposure. We recommend use of a CT scanogram, especially the lateral scout view in patients with flexion deformities at the knee. Newer modalities such as MRI are promising but need further investigation before being routinely employed for assessment of LLD.
LEVEL OF EVIDENCE: Level IV, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.
- Clin Orthop Relat Res
- 1528-1132 (Electronic)
- Publication year:
- Biological and physiological variables:
- Biological and physiological variables
- Adults (18-65)
- Congenital malformations, deformations and chromosomal abnormalities and related symptoms
- PRO / non-PRO:
- Non-patient Reported Outcome
- Type of measurement instrument:
- 7 - Observations
8 - Imaging tests
9 - Laboratory tests
- CR - Computed Radiography
CT - Computed Tomography
MDR - Microdose Digital Radiography
MRI - Magnetic Resonance Imaging (versions: 2D MRI; 3D MRI; pMRI; sMRI; vMRI; rsMRI)
Tape measure (versions: scapula to spine distance)
US - Ultrasound