• 1.

    Piermattei DL, Flo GF, Decamp CE. The stifle joint. In: Handbook of small animal orthopedics and fracture repair. 4th ed. St Louis: Saunders Elsevier, 2006;562632.

    • Search Google Scholar
    • Export Citation
  • 2.

    Priester WA. Sex, size, and breed as risk factors in canine patellar dislocation. J Am Vet Med Assoc 1972; 160:740742.

  • 3.

    Insall J, Salvati E, Goldberg V. Recurrent dislocation and high-riding patella. Clin Orthop 1972; 88:6769.

  • 4.

    Simmons E, Cameron JC. Patella alta and recurrent dislocation of the patella. Clin Orthop 1992; 274:265269.

  • 5.

    Aglietti P, Insall JN, Cerulli G. Patellar pain and incongruence. 1: measurements of incongruence. Clin Orthop 1983; 176:217224.

  • 6.

    Johnson AL, Broaddus KD, Hauptman JG, et al. Vertical patellar position in large-breed dogs with clinically normal stifles and large-breed dogs with medial patellar luxation. Vet Surg 2006; 35:7881.

    • Search Google Scholar
    • Export Citation
  • 7.

    Mostafa AA, Griffon DJ, Thomas MW, et al. Proximodistal alignment of the canine patella: radiographic evaluation and association with medial and lateral patellar luxation. Vet Surg 2008; 37:201211.

    • Search Google Scholar
    • Export Citation
  • 8.

    Grelsamer RP. Patellar nomenclature: the tower of babel revisited. Clin Orthop 2005; 436:6065.

  • 9.

    Johnson AL, Probst CW, Decamp CE, et al. Vertical position of the patella in the stifle joint of clinically normal large-breed dogs. Am J Vet Res 2002; 63:4246.

    • Search Google Scholar
    • Export Citation
  • 10.

    Teitge RA. Plain patellofemoral radiographs. Oper Tech Sport Med 2001; 9:134151.

  • 11.

    Insall J, Salvati E. Patella position in the normal knee joint. Radiology 1971; 101:101104.

  • 12.

    Grelsamer RP, Meadows S. The modified Insall-Salvati ratio for assessment of patellar height. Clin Orthop 1992; 282:170176.

  • 13.

    de Carvalho A, Andersen AH, Topp S, et al. A method for assessing the height of the patella. Int Orthop 1985; 9:195197.

  • 14.

    Seil R, Muller B, Georg T, et al. Reliability and interobserver variability in radiological patellar height ratios. Knee Surg Sports Traumatol Arthrosc 2000; 8:231236.

    • Search Google Scholar
    • Export Citation
  • 15.

    Berg EE, Mason SL, Lucas MJ. Patellar height ratios—comparison of four measurement methods. Am J Sports Med 1996; 24:218221.

  • 16.

    Blackburne JS, Peel TE. New method of measuring patellar height. J Bone Joint Surg Br 1977; 59:241242.

  • 17.

    Caton J, Deschamps G, Chambat P, et al. Patella infera. Apropos of 128 cases [in French]. Rev Chir Orthop Reparatrice Appar Mot 1982; 68:317325.

    • Search Google Scholar
    • Export Citation
  • 18.

    Biedert RM, Albrecht S. The patellotrochlear index: a new index for assessing patellar height. Knee Surg Sports Traumatol Arthrosc 2006; 14:707712.

    • Search Google Scholar
    • Export Citation
  • 19.

    Wayne RK. Limb morphology of domestic and wild canids—the influence of development on morphological change. J Morphol 1986; 187:301319.

    • Search Google Scholar
    • Export Citation
  • 20.

    Danish Law. nr 583 Order on the slaughter and euthanasia of animals, chapter 11, §56 and §59. Available at: www.retsinformation.dk/Forms/R0710.aspx?id=2649#K11. Accessed Oct 13, 2011.

    • Search Google Scholar
    • Export Citation
  • 21.

    Shrout PE, Fleiss JL. Intraclass correlations—uses in assessing rater reliability. Psychol Bull 1979; 86:420428.

  • 22.

    Shrout PE. Measurement reliability and agreement in psychiatry. Stat Methods Med Res 1998; 7:301317.

  • 23.

    Bland JM, Altman DG. Statistics notes: measurement error proportional to the mean. BMJ 1996; 313:106.

  • 24.

    Bland JM, Altman DG. Measuring agreement in method comparison studies. Stat Methods Med Res 1999; 8:135160.

  • 25.

    Colborne GR. Are sound dogs mechanically symmetric at trot? No, actually. Vet Comp Orthop Traumatol 2008; 21:294301.

  • 26.

    Streiner DL, Norman GR. “Precision” and “accuracy”: two terms that are neither. J Clin Epidemiol 2006; 59:327330.

  • 27.

    Caylor KB, Zumpano CA, Evans LM, et al. Intra- and interobserver measurement variability of tibial plateau slope from lateral radiographs in dogs. J Am Anim Hosp Assoc 2001; 37:263268.

    • Search Google Scholar
    • Export Citation
  • 28.

    Fettig AA, Rand WM, Sato AF, et al. Observer variability of tibial plateau slope measurement in 40 dogs with cranial cruciate ligament-deficient stifle joints. Vet Surg 2003; 32:471478.

    • Search Google Scholar
    • Export Citation
  • 29.

    Morris E, Lipowitz AJ. Comparison of tibial plateau angles in dogs with and without cranial cruciate ligament injuries. J Am Vet Med Assoc 2001; 218:363366.

    • Search Google Scholar
    • Export Citation
  • 30.

    Wilke VL, Conzemius MG, Besancon ME, et al. Comparison of tibial plateau angle between clinically normal Greyhounds and Labrador Retrievers with and without rupture of the cranial cruciate ligament. J Am Vet Med Assoc 2002; 221:14261429.

    • Search Google Scholar
    • Export Citation

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Comparison of reliability of five patellar position indices at various stifle joint angles in pelvic limbs obtained from cadavers of red foxes (Vulpes vulpes)

James E. Miles BVetMed1, Dorte H. Nielsen DVM, PhD2, Bente R. Jensen PhD3, Jolle Kirpensteijn DVM, PhD4, Eiliv L. Svalastoga DVM, Dr Med Vet5, and Thomas Eriksen DVM, PhD6
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  • 1 Department of Small Animal Clinical Sciences, Faculty of Life Sciences, Copenhagen University, 1870 Frederiksberg C, Denmark.
  • | 2 Department of Small Animal Clinical Sciences, Faculty of Life Sciences, Copenhagen University, 1870 Frederiksberg C, Denmark.
  • | 3 Department of Exercise and Sport Sciences, Faculty of Science, Copenhagen University, 2200 København N, Denmark.
  • | 4 Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, 3584 CS Utrecht, The Netherlands.
  • | 5 Department of Small Animal Clinical Sciences, Faculty of Life Sciences, Copenhagen University, 1870 Frederiksberg C, Denmark.
  • | 6 Department of Small Animal Clinical Sciences, Faculty of Life Sciences, Copenhagen University, 1870 Frederiksberg C, Denmark.

Abstract

Objective—To compare 5 patellar position indices at various stifle joint angles in cadavers of red foxes, determine measurement reliability, and assess the suitability of these indices for clinical use.

Sample—Pelvic limbs from cadavers of 12 red foxes (Vulpes vulpes).

Procedures—Patellar position in each limb at 7 stifle joint angles (30° to 148°) was assessed by use of the Insall-Salvati (IS), modified Insall-Salvati (mIS), de Carvalho (dC), patellotrochlear (PT), and Blackburne-Peel (BP) indices.

Results—Values for all indices varied significantly on the basis of joint angle, but for IS and mIS indices, this was minor and nonsignificant between 52° and 130° and between 52° and 148°, respectively. The dC index increased linearly, and PT and BP indices varied polynomially with increases in stifle joint angle. Stifle joint angles measured from radiographs agreed well with the goniometrically set stifle joint angles up to approximately 100° and diverged thereafter. Intraobserver and interobserver agreement was substantial for all indices, and IS index was the most precise.

Conclusions and Clinical Relevance—IS and mIS index values were effectively independent of stifle joint angle, in contrast to dC, PT, and BP indices. The BP index varied nonsignificantly across a range of joint angles. To maximize angular accuracy, radiographs should not be obtained at joint angles > 100°. Although dC, PT, and BP indices appeared to be suitable for preoperative and postoperative evaluation of patellar position, BP index appeared to have the most promise for determination of patellar position in clinical applications.

Abstract

Objective—To compare 5 patellar position indices at various stifle joint angles in cadavers of red foxes, determine measurement reliability, and assess the suitability of these indices for clinical use.

Sample—Pelvic limbs from cadavers of 12 red foxes (Vulpes vulpes).

Procedures—Patellar position in each limb at 7 stifle joint angles (30° to 148°) was assessed by use of the Insall-Salvati (IS), modified Insall-Salvati (mIS), de Carvalho (dC), patellotrochlear (PT), and Blackburne-Peel (BP) indices.

Results—Values for all indices varied significantly on the basis of joint angle, but for IS and mIS indices, this was minor and nonsignificant between 52° and 130° and between 52° and 148°, respectively. The dC index increased linearly, and PT and BP indices varied polynomially with increases in stifle joint angle. Stifle joint angles measured from radiographs agreed well with the goniometrically set stifle joint angles up to approximately 100° and diverged thereafter. Intraobserver and interobserver agreement was substantial for all indices, and IS index was the most precise.

Conclusions and Clinical Relevance—IS and mIS index values were effectively independent of stifle joint angle, in contrast to dC, PT, and BP indices. The BP index varied nonsignificantly across a range of joint angles. To maximize angular accuracy, radiographs should not be obtained at joint angles > 100°. Although dC, PT, and BP indices appeared to be suitable for preoperative and postoperative evaluation of patellar position, BP index appeared to have the most promise for determination of patellar position in clinical applications.

Contributor Notes

The authors thank Malin Jacobsson for technical assistance with preparation of the cadavers and Nils Toft for assistance with the statistical analysis.

Address correspondence to Dr. Miles (jami@life.ku.dk).