Comparison of Radiographic Measurements of the Femur in Yorkshire Terriers with and without Medial Patellar Luxation

Abstract

Objective This article aimed to compare measurements of anatomical angles of the femurs, based on radiography, in Yorkshire Terriers without or with various grades of medial patellar luxation (MPL) based on radiography.

Methods The skeletally mature Yorkshire Terrier dogs without MPL and with various grades of MPL were included in this prospective study. Cases with other orthopaedic disorders were excluded. For inclusion of the dog, it was required that standardized digital radiographs of both femurs in craniocaudal and axial directions were available. Measurements of the anatomical lateral proximal femoral angle, anatomical lateral distal femoral angle, femoral varus angle, anteversion angle and femoral inclination angle were performed.

Results Forty-two Yorkshire Terriers (84 hindlimbs) were included in the study. They were divided into five groups according to grade of MPL as healthy (n = 12), grade I (n = 9), grade II (n = 44), grade III (n = 10) and grade IV (n = 9) dogs. The anatomical lateral proximal femoral angle and anteversion angle were significantly lower in dogs with grade IV MPL, while anatomical lateral distal femoral angle and femoral varus angle were significantly higher. The femoral inclination angle values did not differ significantly.

Clinical Significance Yorkshire Terriers affected with grade IV MPL had severe femoral deformities or femoral varus and external rotation of the distal femur. Reference range can be used as an aid in diagnosis, determining indications and surgical planning for corrective osteotomy.

Keywords

patellar luxation - dogs - bone deformity - radiography

Author Contributions

All authors contributed to Conception of the study, study design, acquisition of data, data analysis and interpretation. All authors drafted and revised the manuscript and approved the submitted manuscript.

• References

• 1 LaFond E, Breur GJ, Austin CC. Breed susceptibility for developmental orthopedic diseases in dogs. J Am Anim Hosp Assoc 2002; 38 (05) 467-477
• 2 Piermattei DL, Flo GL, DeCamp CE. The stifle joint. In: Brinker WO, Piermattei DL, Flo GL, DeCamp CE. , eds. Handbook of Small Animal Orthopedics and Fracture Repair. 4th ed. St Louis, MO: Saunders Elsevier; 2006: 562-582
• 3 Johnson JA, Austin C, Breur GJ. Incidence of canine appendicular musculosceletar disorders in 16 veterinary teaching hospitals from 1980 through 1989. Vet Comp Orthop Traumatol 1994; 7: 56-69
• 4 Ness MG, Abercromby CM, Turner BM. , et al. A survey of orthopaedic conditions in small animal veterinary practice in Britain. Vet Comp Orthop Traumatol 1996; 9: 43-52
• 5 Alam MR, Lee JI, Kang HS. , et al. Frequency and distribution of patellar luxation in dogs. 134 cases (2000 to 2005). Vet Comp Orthop Traumatol 2007; 20 (01) 59-64
• 6 Soontornvipart K, Wangdee C, Kalpravidh M. , et al. Incidence and genetic aspects of patellar luxation in Pomeranian dogs in Thailand. Vet J 2013; 196 (01) 122-125
• 7 Hayes AG, Boudrieau RJ, Hungerford LL. Frequency and distribution of medial and lateral patellar luxation in dogs: 124 cases (1982-1992). J Am Vet Med Assoc 1994; 205 (05) 716-720
• 8 Bound N, Zakai D, Butterworth SJ, Pead M. The prevalence of canine patellar luxation in three centres. Clinical features and radiographic evidence of limb deviation. Vet Comp Orthop Traumatol 2009; 22 (01) 32-37
• 9 Hulse DA. Medial patellar luxation in the dog. In: Bojrab MJ. , ed. Disease Mechanisms in Small Animal Surgery. 2nd ed. Philadelphia, PA: Lea&Febiger; 1993: 808-817
• 10 Towle HA, Griffon DJ, Thomas MW, Siegel AM, Dunning D, Johnson A. Pre- and postoperative radiographic and computed tomographic evaluation of dogs with medial patellar luxation. Vet Surg 2005; 34 (03) 265-272
• 11 Alam MR, Lee HB, Kim MS, Kim NS. Surgical model of osteoarthritis secondary to medial patellar luxation in dogs. Vet Med 2011; 3: 123-130
• 12 Roy RG, Wallace LJ, Johnston GR, Wickstrom SL. A retrospective evaluation of stifle osteoarthritis in dogs with bilateral medial patellar luxation and unilateral surgical repair. Vet Surg 1992; 21 (06) 475-479
• 13 Tomlinson J, Fox D, Cook JL, Keller GG. Measurement of femoral angles in four dog breeds. Vet Surg 2007; 36 (06) 593-598
• 14 Dismukes DI, Tomlinson JL, Fox DB, Cook JL, Witsberger TH. Radiographic measurement of canine tibial angles in the sagittal plane. Vet Surg 2008; 37 (03) 300-305
• 15 Pettazoni M, Jaeger GH. Radiographic measurements of the femur. In: Pettazoni M, Jaeger GH. , eds. Atlas of Clinical Goniometry and Radiographic Measurements of the Canine Pelvic Limb. 2nd ed. Milano: Merial; 2008: 34-58
• 16 Swiderski JK, Radecki SV, Park RD, Palmer RH. Comparison of radiographic and anatomic femoral varus angle measurements in normal dogs. Vet Surg 2008; 37 (01) 43-48
• 17 Yasukawa S, Edamura K, Tanegashima K. , et al. 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 (01) 29-38
• 18 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; 52 (01) 45-50
• 19 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 (03) 197-201
• 20 Singleton WB. The surgical correction of stifle deformities in the dog. J Small Anim Pract 1969; 10 (02) 59-69
• 21 Dudley RM, Kowaleski MP, Drost WT, Dyce J. Radiographic and computed tomographic determination of femoral varus and torsion in the dog. Vet Radiol Ultrasound 2006; 47 (06) 546-552
• 22 Fitzpatrick CL, Krotscheck U, Thompson MS, Todhunter RJ, Zhang Z. Evaluation of tibial torsion in Yorkshire Terriers with and without medial patellar luxation. Vet Surg 2012; 41 (08) 966-972
• 23 Wangdee C, Theyse LF, Hazewinkel HA. Proximo-distal patellar position in three small dog breeds with medial patellar luxation. Vet Comp Orthop Traumatol 2015; 28 (04) 270-273
• 24 Mortari AC, Rahal SC, Vulcano LC, da Silva VC, Volpi RS. Use of radiographic measurements in the evaluation of dogs with medial patellar luxation. Can Vet J 2009; 50 (10) 1064-1068
• 25 Aiken M, Barnes D. Are the fabellae bisected by the femoral cortices in a true craniocaudal pelvic limb radiograph?. J Small Anim Pract 2014; 55 (09) 465-470
• 26 Bardet JF, Rudy RL, Hohn RB. Measurement of femoral torsion in dogs using a biplanar method. Vet Surg 1983; 12: 1-6
• 27 L'Eplattenier H, Montavon P. Patellar luxation in dogs and cats: pathogenesis and diagnosis. Compend Contin Educ Pract Vet 2002; 24: 234-239
• 28 Kaiser S, Cornely D, Golder W. , et al. The correlation of canine patellar luxation and the anteversion angle as measured using magnetic resonance images. Vet Radiol Ultrasound 2001; 42 (02) 113-118
• 29 Banfield CM, Bartels JE, Hudson JA, Wright JC, Hathcock JT, Montgomery RD. A retrospective study of canine hip dysplasia in 116 military working dogs. Part I: angle measurements and orthopedic foundation for animals (OFA) grading. J Am Anim Hosp Assoc 1996; 32 (05) 413-422
• 30 Brower BE, Kowaleski MP, Peruski AM. , et al. Distal femoral lateral closing wedge osteotomy as a component of comprehensive treatment of medial patellar luxation and distal femoral varus in dogs. Vet Comp Orthop Traumatol 2017; 30 (01) 20-27