A Comparison of Angular Values of the Pelvic Limb with Normal and Medial Patellar Luxation Stifles in Chihuahua Dogs Using Radiography and Computed Tomography

Abstract

Objective This article aimed to determine and compare the angular values of the pelvic limb in normal and medial patellar luxation (MPL) stifles in Chihuahuas using radiography and computed tomographic (CT) scan, to identify the relationship between pelvic limb angles and severity of MPL. In addition, radiographic and CT images were compared to determine the more suitable method of limb deformity assessment.

Methods Sixty hindlimbs of Chihuahuas were divided into normal and grade 1, 2, 3 and 4 MPL groups. The pelvic limb angles in frontal and sagittal planes were evaluated on radiography and CT scan. Femoral and tibial torsion angles (FTA and TTA) were evaluated only by CT scan. All angles were compared among normal and MPL stifles and between radiography and CT scan.

Results Based on the CT scan, the mechanical lateral distal femoral angle (mLDFA), anatomical caudal proximal femoral angle (aCdPFA), and TTA were related to the severity of MPL. The mLDFA and TTA were significantly increased (p < 0.05) in grade 4 MPL, while the aCdPFA was significantly decreased in grade 2, 3 and 4 MPL groups. There were significant differences of many angles between radiography and CT scan.

Clinical Significance The angles related to MPL in Chihuahuas are aLDFA, mLDFA, aCdPFA and TTA. Radiography had some limitations for evaluating pelvic limb angles. The caudocranial radiograph is recommended for the assessment of the distal femoral angles, while the craniocaudal radiograph is for the tibial angles.

Keywords

Chihuahua - medial patellar luxation - pelvic limb deformity - computed tomography - radiography

Author Contributions

All authors contributed to the study conception. T. Phetkaew and C. Wangdee contributed to the study design. T. Phetkaew, R. Penchome and C. Wangdee contributed to the acquisition of data. All authors contributed to data analysis and interpretation, drafting or revising of the manuscript, and approved the submitted manuscript.

• References

• 1 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
• 2 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
• 3 Trotter EJ. Medial patellar luxation in dog. Compend Contin Educ Pract Vet 1980; 2: 58-66
• 4 LaFond E, Breur GJ, Austin CC. Breed susceptibility for developmental orthopedic diseases in dogs. J Am Anim Hosp Assoc 2002; 38 (05) 467-477
• 5 DeAngelis M, Hohn RB. Evaluation of surgical correction of canine patellar luxation in 142 cases. J Am Vet Med Assoc 1970; 156 (05) 587-594
• 6 Gibbons SE, Macias C, Tonzing MA, Pinchbeck GL, McKee WM. Patellar luxation in 70 large breed dogs. J Small Anim Pract 2006; 47 (01) 3-9
• 7 Hulse DA. Pathophysiology and management of medial patellar luxation in the dog. Vet Med Small Anim Clin 1981; 76 (01) 43-51
• 8 Roush JK. Canine patellar luxation. Vet Clin North Am Small Anim Pract 1993; 23 (04) 855-868
• 9 Orthopedic Foundation for Animals: Patellar Luxation Statistics, 2016. Available at: http://www.ofa.org/stats_pl.html . Accessed December 5, 2017
• 10 Priester WA. Sex, size, and breed as risk factors in canine patellar dislocation. J Am Vet Med Assoc 1972; 160 (05) 740-742
• 11 Bosio F, Bufalari A, Peirone B, Petazzoni M, Vezzoni A. Prevalence, treatment and outcome of patellar luxation in dogs in Italy. A retrospective multicentric study (2009-2014). Vet Comp Orthop Traumatol 2017; 30 (05) 364-370
• 12 Hulse DA. Medial Patellar Luxation in the Dog. Borab MJ. , ed. Philadelphia, PA: Lea & Febiger; 1993
• 13 Piermattei DL, Flo GL, DeCamp CE. The Stifle Joint. Handbook of Small Animal Orthopedics and Fracture Repair, 4th ed. St. Louis, MO: Saunders; 2006: 562-582
• 14 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
• 15 Paley D. Normal lower limb alignment and joint orientation. Principle of Deformity Correction. Berlin, Germany: Springer-Verlag; 2003
• 16 Petazzoni M, Jaeger GH. Atlas of clinical goniometry and radiographic measurements of the canine pelvic limb. 2nd ed. Milan, Italy: Merial; 2008
• 17 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
• 18 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
• 19 Slocum B, Slocum TD. Alignment problems of the hindlimb. Proceedings of the 10th ESVOT Congress; Munich, Germany; 2000:60–62
• 20 Tomlinson J, Fox D, Cook JL, Keller GG. Measurement of femoral angles in four dog breeds. Vet Surg 2007; 36 (06) 593-598
• 21 Willauer CC, Vasseur PB. Clinical results of surgical correction of medial luxation of the patella in dogs. Vet Surg 1987; 16 (01) 31-36
• 22 Arthurs GI, Langley-Hobbs SJ. Complications associated with corrective surgery for patellar luxation in 109 dogs. Vet Surg 2006; 35 (06) 559-566
• 23 Fox DB, Tomlinson JL. Principles of angular limb deformity correction. In: Tobias KM, Johnston SA. , eds. Veterinary Surgery: Small Animal. Vol 1. St. Louis, MO: Elsevier Saunders; 2012: 657-668
• 24 Kowaleski MP. Femoral corrective osteotomy for medial patellar luxation. Proceedings of the ACVS Veterinary Symposium, Washington, DC; 2006
• 25 Bruecker K. Femoral corrective osteotomy for the treatment of medial patella luxation. 14th Annual ESVOT, Munich, Germany; 2006
• 26 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
• 27 Roch SP, Gemmill TJ. Treatment of medial patellar luxation by femoral closing wedge ostectomy using a distal femoral plate in four dogs. J Small Anim Pract 2008; 49 (03) 152-158
• 28 Petazzoni M. Hind limb alignment in the dog to treat patellar luxation: a retrospective study of 39 cases (2001–2005). 13th Conference of the European Society of Veterinary Orthopaedics and Traumatology, Munich, Germany; 2006
• 29 Perry KL, Adams RJ, Andrews SJ, Tewson C, Bruce M. Impact of femoral varus on complications and outcome associated with corrective surgery for medial patellar luxation. Vet Comp Orthop Traumatol 2017; 30 (04) 288-298
• 30 Hazewinkel HAW, Tellhelm B, Leegwater PA. Screening for orthopaedic genetic defects: Part 1. Patella luxation in dogs. Eur J Companion Anim Pract 2013; 23: 90-98
• 31 Singleton WB. The surgical correction of stifle deformities in the dog. J Small Anim Pract 1969; 10 (02) 59-69
• 32 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
• 33 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
• 34 Dismukes DI, Tomlinson JL, Fox DB, Cook JL, Song KJE. Radiographic measurement of the proximal and distal mechanical joint angles in the canine tibia. Vet Surg 2007; 36 (07) 699-704
• 35 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
• 36 Apelt D, Kowaleski MP, Dyce J. Comparison of computed tomographic and standard radiographic determination of tibial torsion in the dog. Vet Surg 2005; 34 (05) 457-462
• 37 Aper R, Kowaleski MP, Apelt D, Drost WT, Dyce J. Computed tomographic determination of tibial torsion in the dog. Vet Radiol Ultrasound 2005; 46 (03) 187-191
• 38 Palmer R. Controversial in the management of patellar luxation. Proceedings of the BVOA Spring Scientific Meeting, Birmingham, England; 2008
• 39 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; 30 (03) 200-208
• 40 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; 30 (03) 191-199
• 41 Jackson GM, Wendelburg KL. Evaluation of the effect of distal femoral elevation on radiographic measurement of the anatomic lateral distal femoral angle. Vet Surg 2012; 41 (08) 994-1001