Clinical Orthopaedics and Related Research

, Volume 466, Issue 12, pp 2910–2922

Methods for Assessing Leg Length Discrepancy

Symposium: Advances in Limb Lengthening and Reconstruction

Abstract

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.

References

  1. 1.
    Aaron A, Weinstein D, Thickman D, Eilert R. Comparison of orthoroentgenography and computed tomography in the measurement of limb-length discrepancy. J Bone Joint Surg Am. 1992;74:897–902.PubMedGoogle Scholar
  2. 2.
    Aitken GF, Flodmark O, Newman DE, Kilcoyne RF, Shuman WP. Mack LA. Leg length determination by CT digital radiography. AJR Am J Roentgenol. 1985;144:613–615.PubMedGoogle Scholar
  3. 3.
    Altongy JF, Harcke HT, Bowen JR. Measurement of leg length inequalities by Micro-Dose digital radiographs. J Pediatr Orthop. 1987;7:311–316.PubMedGoogle Scholar
  4. 4.
    Aspegren DD, Cox JM, Trier KK. Short leg correction: a clinical trial of radiographic vs. non-radiographic procedures. J Manipulative Physiol Ther. 1987;10:232–238.PubMedGoogle Scholar
  5. 5.
    Badii M, Shin S, Torreggiani WC, Jankovic B, Gustafson P, Munk PL, Esdaile JM. Pelvic bone asymmetry in 323 study participants receiving abdominal CT scans. Spine. 2003;28:1335–1339.PubMedCrossRefGoogle Scholar
  6. 6.
    Baylis WJ, Rzonca EC. Functional and structural limb length discrepancies: evaluation and treatment. Clin Podiatr Med Surg. 1988;5:509–520.PubMedGoogle Scholar
  7. 7.
    Beattie P, Isaacson K, Riddle DL, Rothstein JM. Validity of derived measurements of leg-length differences obtained by use of a tape measure. Phys Ther. 1990;70:150–157.PubMedGoogle Scholar
  8. 8.
    Cleveland RH, Kushner DC, Ogden MC, Herman TE, Kermond W, Correia JA. Determination of leg length discrepancy. A comparison of weight-bearing and supine imaging. Invest Radiol. 1988;23:301–304.PubMedCrossRefGoogle Scholar
  9. 9.
    Defrin R, Ben Benyamin S, Aldubi RD, Pick CG. Conservative correction of leg-length discrepancies of 10 mm or less for the relief of chronic low back pain. Arch Phys Med Rehabil. 2005;86:2075–2080.PubMedCrossRefGoogle Scholar
  10. 10.
    Fisk JW, Baigent ML. Clinical and radiological assessment of leg length. N Z Med J. 1975;81:477–480.PubMedGoogle Scholar
  11. 11.
    French SD, Green S, Forbes A. Reliability of chiropractic methods commonly used to detect manipulable lesions in patients with chronic low-back pain. J Manipulative Physiol Ther. 2000;23:231–238.PubMedCrossRefGoogle Scholar
  12. 12.
    Glass RB, Poznanski AK. Leg-length determination with biplanar CT scanograms. Radiology. 1985;156:833–834.PubMedGoogle Scholar
  13. 13.
    Green WT, Wyatt GM, Anderson M. Orthoroentgenography as a method of measuring the bones of the lower extremities. J Bone Joint Surg Am. 1946;28:60–65.Google Scholar
  14. 14.
    Gurney B. Leg length discrepancy. Gait Posture. 2002;15:195–206.PubMedCrossRefGoogle Scholar
  15. 15.
    Hanada E, Kirby RL, Mitchell M, Swuste JM. Measuring leg-length discrepancy by the “iliac crest palpation and book correction” method: reliability and validity. Arch Phys Med Rehabil. 2001;82:938–942.PubMedCrossRefGoogle Scholar
  16. 16.
    Harris I, Hatfield A, Walton J. Assessing leg length discrepancy after femoral fracture: clinical examination or computed tomography? ANZ J Surg. 2005;75:319–321.PubMedCrossRefGoogle Scholar
  17. 17.
    Helms CA, McCarthy S. CT scanograms for measuring leg length discrepancy. Radiology. 1984;151:802.PubMedGoogle Scholar
  18. 18.
    Horsfield D, Jones SN. Assessment of inequality in length of the lower limb. Radiography. 1986;52:223–227.PubMedGoogle Scholar
  19. 19.
    Huurman WW, Jacobsen FS, Anderson JC, Chu WK. Limb-length discrepancy measured with computerized axial tomographic equipment. J Bone Joint Surg Am. 1987;69:699–705.PubMedGoogle Scholar
  20. 20.
    Jonson SR, Gross MT. Intraexaminer reliability, interexaminer reliability, and mean values for nine lower extremity skeletal measures in healthy naval midshipmen. J Orthop Sports Phys Ther. 1997;25:253–263.PubMedGoogle Scholar
  21. 21.
    Kogutt MS. Computed radiographic imaging: use in low-dose leg length radiography. AJR Am J Roentgenol. 1987;148:1205–1206.PubMedGoogle Scholar
  22. 22.
    Konermann W, Gruber G. Ultrasound determination of leg length [in German]. Orthopade. 2002;31:300–305.PubMedCrossRefGoogle Scholar
  23. 23.
    Krettek C, Koch T, Henzler D, Blauth M, Hoffmann R. A new procedure for determining leg length and leg length inequality using ultrasound. II: Comparison of ultrasound, teleradiography and 2 clinical procedures in 50 patients [in German]. Unfallchirurg. 1996;99:43–51.PubMedGoogle Scholar
  24. 24.
    Lampe HI, Swierstra BA, Diepstraten AF. Measurement of limb length inequality. Comparison of clinical methods with orthoradiography in 190 children. Acta Orthop Scand. 1996;67:242–244.PubMedGoogle Scholar
  25. 25.
    Leitzes AH, Potter HG, Amaral T, Marx RG, Lyman S, Widman RF. Reliability and accuracy of MRI scanogram in the evaluation of limb length discrepancy. J Pediatr Orthop. 2005;25:747–749.PubMedCrossRefGoogle Scholar
  26. 26.
    Machen MS, Stevens PM. Should full-length standing anteroposterior radiographs replace the scanogram for measurement of limb length discrepancy? J Pediatr Orthop B. 2005;14:30–37.PubMedGoogle Scholar
  27. 27.
    Merrill OE. A method for the roentgen measurement of the long bones. Am J Roentgenol Radium Ther Nucl Med. 1942;48:405–406.Google Scholar
  28. 28.
    Millwee RH. Slit scanography. Radiology. 1937;28:483–486.Google Scholar
  29. 29.
    Moseley CF. Leg length discrepancy. In: Morrissy RT, Weinstein SL, eds. Lovell and Winter’s Pediatric Orthopedics. Philadelphia, PA: Lippincott Williams & Wilkins; 2006;1213–1256.Google Scholar
  30. 30.
    Okun SJ, Morgan JW Jr, Burns MJ. Limb length discrepancy: a new method of measurement and its clinical significance. J Am Podiatry Assoc. 1982;72:595–599.PubMedGoogle Scholar
  31. 31.
    Petrone MR, Guinn J, Reddin A, Sutlive TG, Flynn TW, Garber MP. The accuracy of the Palpation Meter (PALM) for measuring pelvic crest height difference and leg length discrepancy. J Orthop Sports Phys Ther. 2003;33:319–325.PubMedGoogle Scholar
  32. 32.
    Porat S, Fields S. Limb length discrepancy determined by computerized tomography and radiography [in Hebrew]. Harefuah. 1989;116:515–516.PubMedGoogle Scholar
  33. 33.
    Rhodes DW, Mansfield ER, Bishop PA, Smith JF. Comparison of leg length inequality measurement methods as estimators of the femur head height difference on standing Xray. J Manipulative Physiol Ther. 1995;18:448–452.PubMedGoogle Scholar
  34. 34.
    Rhodes DW, Mansfield ER, Bishop PA, Smith JF. The validity of the prone leg check as an estimate of standing leg length inequality measured by Xray. J Manipulative Physiol Ther. 1995;18:343–346.PubMedGoogle Scholar
  35. 35.
    Rondon CA, Gonzalez N, Agreda L, Millan A. Observer agreement in the measurement of leg length. Rev Invest Clin. 1992;44:85–89.PubMedGoogle Scholar
  36. 36.
    Sabharwal S, Badarudeen S, McClemens E, Choung E. The effect of circular external fixation on limb alignment. J Pediatr Orthop. 2008;28:314–319.PubMedGoogle Scholar
  37. 37.
    Sabharwal S, Zhao C, McKeon J, Melaghari T, Blacksin M, Wenekor C. Reliability analysis for radiographic measurement of limb length discrepancy: Full-length standing anteroposterior radiograph versus Scanogram. J Pediatr Orthop. 2007;27:46–50.PubMedGoogle Scholar
  38. 38.
    Sabharwal S, Zhao C, McKeon JJ, McClemens E, Edgar M, Behrens F. Computed radiographic measurement of limb-length discrepancy. Full-length standing anteroposterior radiograph comared with scanogram. J Bone Joint Surg Am. 2006;88:2243–2251.PubMedCrossRefGoogle Scholar
  39. 39.
    Saleh M, Milne A. Weight-bearing parallel-beam scanography for the measurement of leg length and joint alignment. J Bone Joint Surg Br. 1994;76:156–157.PubMedGoogle Scholar
  40. 40.
    Shapiro F. Pediatric Orthopedic Deformities. Basic Science, Diagnosis, and Treatment. San Diego, CA: Academic Press; 2001;606–732.Google Scholar
  41. 41.
    Temme JB, Chu WK, Anderson JC. CT scanograms compared with conventional orthoroentgenograms in long bone measurement. Radiol Technol. 1987;59:65–68.PubMedGoogle Scholar
  42. 42.
    Terjesen T, Benum P, Rossvoll I, Svenningsen S, Floystad Isern AE, Nordbo T. Leg-length discrepancy measured by ultrasonography. Acta Orthop Scand. 1991;62:121–124.PubMedCrossRefGoogle Scholar
  43. 43.
    Terry MA, Winell JJ, Green DW, Schneider R, Peterson M, Marx RG, Widmann RF. Measurement variance in limb length discrepancy: Clinical and radiographic assessment of interobserver and intraobserver variability. J Pediatr Orthop. 2005;25:197–201.PubMedCrossRefGoogle Scholar
  44. 44.
    Tokarowski A, Piechota L, Wojciechowski P, Gajos L, Kusz D. Measurement of lower extremity length using computed tomography [in Polish]. Chir Narzadow Ruchu Ortop Pol. 1995;60:123–127.PubMedGoogle Scholar

Copyright information

© The Association of Bone and Joint Surgeons 2008

Authors and Affiliations

  1. 1.Division of Pediatric Orthopaedics, Department of OrthopaedicsUMDNJ—New Jersey Medical SchoolNewarkUSA

Personalised recommendations