Femoral inclination angle - Dog - axes and angles - Thigh bone [Femur] - vet-Anatomy
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Femoral inclination angle

Femoral inclination angle

  • Synonym: Femoral neck inclination angle; Femoral neck angle; Femoral head inclination angle; cervicodiaphyseal angle of the femur
  • Acronym: FIA

Definition

Stephan Mahler

The femoral inclination angle is a measurement used to assess angular deformations of the femur and guide corrections. It is determined from radiographs and multiplanar reconstructions of the femur.

The femoral inclination angle is determined in the frontal plane from a ventrodorsal radiograph of the hips. The dog is positioned in dorsal recumbency, pelvic limbs extended caudally, femurs parallel to each other. Positioning is considered satisfactory if :

Several methods have been described for determining the femoral inclination angle:

Montavon method and Hauptman A method

The femoral inclination angle is the angle between the femoral neck axis and the anatomic femoral axis.

Symax method

A circle delimiting the femoral head as closely as possible is drawn and the center of the femoral head is determined. A second circle is drawn at the proximal end of the femur, so as to touch the edges of the femur in three places (proximal, medial and lateral). The center of this second circle is determined. The femoral neck axis is the line joining the two previously determined centers.

Hauptman A method

Two circles are drawn at the proximal and distal ends of the femur, so as to touch the edges of the femur at three different points (medial, lateral and proximal or distal). The centers of these circles are determined and a straight line is drawn to connect them. The femoral inclination angle is the angle between this straight line and the femoral neck axis.

The following values have been published for the femoral inclination angle in different breeds.

  • Large breeds: 146.2 +/- 4.8° (Hauptman et al. 1979)

  • Small breeds: 130 +/- 6.5° (Olimpo et al. 2016)

  • Small breeds: 129° (117-146) (Garnoeva et al. 2018)

  • Combination of small and large breeds: 148.8 +/- 3.7° (Montavon et al. 1985)

  • Combination of small and large breeds: 146.24 +/- 5.49° (Kara et al. 2018)

  • German Shepherd: 129.90 +/- 0.46° (Sarierler 2004)

  • German shepherd: 132 +/- 5.9° (Tomlinson et al. 2007)

  • Labrador retriever: 131.61 +/- 0.76° (Sarierler 2004)

  • Labrador retriever: 134 +/- 5.3° (Tomlinson et al. 2007)

  • Pointer: 129.84 +/- 0.98° (Sarierler 2004)

  • Irish setter: 128.91 +/- 1.51° (Sarierler 2004)

  • Anatolian Karabach: 138.60 +/- 1.29° (Sarierler 2004)

  • Doberman pinscher: 127.04 +/- 1.07° (Sarierler 2004)

  • Golden retriever: 129.25 +/- 2.75° (Sarierler 2004) ;

  • Golden retriever: 134 +/- 5.2° (Tomlinson et al. 2007)

  • Rottweiler: 137 +/- 5.4° (Tomlinson et al. 2007)

  • Pomeranian: 136.46 +/- 7.12° (Soparat et al. 2012)

  • Yorkshire terrier: 125.39 +/- 4.13° (Žilinčík et al. 2018)

  • Toy poodle: 127.7 +/- 6.3° (116.8 +/- 6.1° CT) (Yasukawa et al. 2016)

  • English bulldog: 129.11 +/- 8.03° (Lusetti et al. 2017)

  • English Staffordshire bull terrier: 136.72 +/- 8.27° (Newman and Voss 2017)

  • Chihuahua: 133.2 +/- 7.9° (CrCd); 131.3 +/- 3.6°(CdCr); 130.9 +/- 4.4° (CT) ( Phetkaew et al. 2018)

References

  • Aghapour M, Bockstahler B, Vidoni B. Evaluation of the Femoral and Tibial Alignments in Dogs: A Systematic Review. Animals (Basel). 2021 Jun 17;11(6):1804. doi: 10.3390/ani11061804. PMID: 34204283; PMCID: PMC8234394.

  • Montavon PM, ; Hohn RB, Olmstead ML, Rudy RL. Inclination and Anteversion Angles of the Femoral Head and Neck in the Dog Evaluation of a Standard Method of Measurement. Vet Surg. 1985 14(4), 277–82. doi:10.1111/j.1532-950x.1985.tb00883.x

  • Rumph PF, Hathcock JT. A symmetric axis-based method for measuring the projected femoral angle of inclination in dogs. Vet Surg. 1990 Sep-Oct;19(5):328-33. doi: 10.1111/j.1532-950x.1990.tb01200.x.

  • Hauptman J, Prieur WD, Butler HC, Guffy MM. The angles of inclination of the canine femoral head and neck. Vet Surg. 1979;8(3):74-77. doi.org/10.1111/j.1532-950X.1979.tb00612.x

  • Olimpo M, Piras LA, Peirone B. Pelvic limb alignment in small breed dogs: a comparison between affected and free subjects from medial patellar luxation. Vet Ital. 2016 Jan-Mar;52(1):45-50. doi: 10.12834/VetIt.71.206.3.

  • Garnoeva, R, Roydev, R, Paskalev, M et al. Radiographic measures of pelvic limb malalignment in small breed dogs with various grades of medial patellar luxation. Comp Clin Pathol 2018;27, 1551–1555. doi.org/10.1007/s00580-018-2772-8.

  • Kara ME, Sevil-Kilimci F, Dilek ÖG, Onar V. Proximal and distal alignment of normal canine femurs: A morphometric analysis. Ann Anat. 2018 May;217:125-128. doi: 10.1016/j.aanat.2018.02.006. Epub 2018 Mar 19.

  • Sarierler, M. Comparison of femoral inclination angle measurements in dysplastic and nondysplastic dogs of different breeds. Acta Vet. 2004, 52, 245–252.doi: https://doi.org/10.1556/avet.52.2004.2.13

  • Tomlinson J, Fox D, Cook JL, Keller GG. Measurement of femoral angles in four dog breeds. Vet Surg. 2007 Aug;36(6):593-8. doi: 10.1111/j.1532-950X.2007.00309.x.

  • Soparat C, Wangdee C, Chuthatep S, Kalpravidh M. Radiographic measurement for femoral varus in Pomeranian dogs with and without medial patellar luxation. Vet Comp Orthop Traumatol. 2012;25(3):197-201. doi: 10.3415/VCOT-11-04-0057. Epub 2012 Jan 27.

  • Žilinčík M, Hluchý M, Takáč L, Ledecký V. Comparison of Radiographic Measurements of the Femur in Yorkshire Terriers with and without Medial Patellar Luxation. Vet Comp Orthop Traumatol. 2018 Jan;31(1):17-22. doi: 10.3415/VCOT-17-01-0018. Epub 2018 Jan 11.

  • Yasukawa S, Edamura K, Tanegashima K, Seki M, Teshima K, Asano K, Nakayama T, Hayashi K. Evaluation of bone deformities of the femur, tibia, and patella in Toy Poodles with medial patellar luxation using computed tomography. Vet Comp Orthop Traumatol. 2016;29(1):29-38. doi: 10.3415/VCOT-15-05-0089. Epub 2015 Dec 7.

  • Lusetti F, Bonardi A, Eid C, Brandstetter de Belesini A, Martini FM. Pelvic limb alignment measured by computed tomography in purebred English Bulldogs with medial patellar luxation. Vet Comp Orthop Traumatol. 2017 May 10;30(3):200-208. doi: 10.3415/VCOT-16-07-0116. Epub 2017 May 5.

  • Newman M, Voss K. Computed tomographic evaluation of femoral and tibial conformation in English Staffordshire Bull Terriers with and without congenital medial patellar luxation. Vet Comp Orthop Traumatol. 2017 May 22;30(3):191-199. doi: 10.3415/VCOT-16-12-0162. Epub 2017 Mar 23. Erratum in: Vet Comp Orthop Traumatol. 2017 Jul 10;30(4)

  • Phetkaew T, Kalpravidh M, Penchome R, Wangdee C. A Comparison of Angular Values of the Pelvic Limb with Normal and Medial Patellar Luxation Stifles in Chihuahua Dogs Using Radiography and Computed Tomography. Vet Comp Orthop Traumatol. 2018 Feb;31(2):114-123. doi: 10.3415/VCOT-17-05-0067. Epub 2018 Mar 13. Erratum in: Vet Comp Orthop Traumatol. 2018 Feb;31(2):a1.

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