Mechanical lateral proximal femoral angle
Mechanical lateral proximal femoral angle
- Acronym: mLPFA
Definition
The mechanical lateral proximal femoral angle (mLPFA) 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.
For radiographic acquisition, the dog is positioned in dorsal recumbency, pelvic limbs extended caudally, femurs parallel to each other. Positioning is considered satisfactory if :
the pelvis is symmetrical: the iliums and obturator foramina are symmetrical.
the femur cortex pass through the middle of the sesamoid bones of the gastrocnemius muscle
the patellas are centered on the trochlea of the femur.The proximal lateral mechanical angle of the femur is the angle at the intersection of the mechanical axis of the femur and the proximal joint orientation line of the femur.
The following values have been published for the proximal lateral mechanical angle of the femur:
Labrador retriever 100 +/- 6.0° (Radiograph) Tomlinson et al. 2007
Golden retriever 95 +/- 5.2° (Radiograph) Tomlinson et al. 2007
German shepherd 97 +/- 4.5° (Radiography) Tomlinson et al. 2007
Rottweiler 93 +/- 4.7° (Radiograph) Tomlinson et al. 2007
Small breeds 105.1 +/- 4.6° (Radiography) Olimpo et al. 2016
Small breeds 107° (90-127) (Radiography) Garnoeva et al. 2018
Poodle toy 102.1 +/- 8.8° (Radiograph) Yasukawa et al. 2016
Poodle toy 113.6 +/- 6.1° (CT) Yasukawa et al. 2016
English bulldog 111.02 +/- 6.90° (CT) Lusetti et al. 2017
Chihuahua 109.9 +/- 7.9° (X-ray CrCd) 108.5 +/- 8.2 (X-ray CdCr) Phetkaew et al. 2018
Chihuahua 120 +/- 7.1° (CT) Phetkaew et al. CT 2018
References
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.
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.
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.
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.
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.
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.