History
A 1.5-year-old spayed female Airedale Terrier was evaluated for non–weight-bearing lameness after being hit by an automobile that same day. Physical examination revealed that the dog was alert, had tachycardia, and was holding its right hind limb in an adducted and externally rotated position. Craniodorsal displacement of the right greater trochanter was detected, but no other pelvic instability or crepitus was identified. The dog was treated with 0.5 mg of morphine/kg (0.23 mg/lb), IM, and 500 mL of an isotonic electrolyte solution, IV. Values for blood pressure readings, PCV, total protein, and electrolytes as well as orthogonal radiographic views of the dog's thorax were all determined to be within expected limits. Treatment was continued with IV administration of fluids and fentanyl (3 μg/kg/h [1.35 μg/lb/h]). A lateral radiographic view of the pelvis was obtained and confirmed right craniodorsal hip joint luxation. A ventrodorsal (VD) radiographic view was not obtained. The dog was anesthetized, and closed reduction of the right hip joint was achieved. Lateral and VD radiographic views of the pelvis were obtained after reduction (Figure 1).
Lateral (A) and ventrodorsal (VD) (B) radiographic views of the pelvis and hip joints of a 1.5-year-old dog after the right hip joint was reduced.
Citation: Journal of the American Veterinary Medical Association 232, 1; 10.2460/javma.232.1.35
Lateral (A) and ventrodorsal (VD) (B) radiographic views of the pelvis and hip joints of a 1.5-year-old dog after the right hip joint was reduced.
Citation: Journal of the American Veterinary Medical Association 232, 1; 10.2460/javma.232.1.35
Lateral (A) and ventrodorsal (VD) (B) radiographic views of the pelvis and hip joints of a 1.5-year-old dog after the right hip joint was reduced.
Citation: Journal of the American Veterinary Medical Association 232, 1; 10.2460/javma.232.1.35
Determine whether additional imaging studies are required, or make your diagnosis from Figure 1—then turn the page →
Same VD view (detail) as in Figure 1. Notice the radiolucent fracture line in the epiphysis of the right femoral head (black arrows). No fragment displacement was noticed.
Citation: Journal of the American Veterinary Medical Association 232, 1; 10.2460/javma.232.1.35
Same VD view (detail) as in Figure 1. Notice the radiolucent fracture line in the epiphysis of the right femoral head (black arrows). No fragment displacement was noticed.
Citation: Journal of the American Veterinary Medical Association 232, 1; 10.2460/javma.232.1.35
Same VD view (detail) as in Figure 1. Notice the radiolucent fracture line in the epiphysis of the right femoral head (black arrows). No fragment displacement was noticed.
Citation: Journal of the American Veterinary Medical Association 232, 1; 10.2460/javma.232.1.35
Radiographic Findings and Interpretation
A proximal epiphyseal fracture of the right femur is evident (Figure 2). There is minimal displacement of the fracture fragment, and the right femoral head is adequately reduced within the acetabulum.
Comments
The owner declined surgical intervention and chose conservative management, including maintaining an Ehmer sling for 2 weeks, oral administration of anti-in-flammatory and pain medications, and gradual return to function over another 6 to 8 weeks.
Fractures of the femoral capital epiphysis are uncommon in cats and dogs and are most often found after hip joint luxation.1 The fracture fragments are often retained within the acetabulum and can be small or make up a large portion of the articular surface of the femoral epiphysis.1 The size of the epiphyseal fragment dictates the method of surgical repair. Small fragments may be excised, but larger fragments are amenable to reduction and fixation by use of interfragmentary lag screws and Kirschner wires.1 Fractures that cannot be reduced may be treated with femoral head and neck ostectomy or total hip replacement.1 Conservative management of femoral capital epiphyseal fractures may lead to incomplete hipjoint reduction, pain, reluxation, and secondary osteoarthritis.1
Accurate radiographic assessment of intra-articular hip joint fractures is essential to determine the proper treatment modality. Identification of proximal femoral fractures can be difficult, and small epiphyseal fragments may not be detected with plain film radiography. Computed axial tomography (CT) was found to have increased sensitivity in identifying loose bone fragments in the human hip joint, compared with plain radiography.2 In humans, CT is recommended for routine evaluation of femoral head and acetabular fractures because of its ability to define fracture size, location, and comminution as well as identify any intra-articular loose fragments.3 A small cohort of dogs with pelvic trauma was recently examined with multiple-angle plain radiography and CT. The investigators concluded that CT was superior to plain radiography for identification of skeletal pelvic trauma, but no femoral head fractures were found during the study. Magnetic resonance imaging may also be used to detect occult hip joint fractures, but 1 human study5 found magnetic resonance imaging of the femoral head inferior to CT because 36% of intra-articular fracture fragments were not detected. Advanced cross-section-al imaging is not readily available to all veterinary practices. If the clinician is suspicious of an occult in-tra-articular hip joint fracture, then CT imaging or multiple, tangential radiographic views of the affected hip joint must be obtained. It should be kept in mind that the plane of the fracture must approximate or be parallel to the incident radiographic beam to be discovered.
Ventrodorsal radiographic view of the pelvis 8 months after reduction of the right hip joint. Moderate displacement of the fracture fragment (black arrow) is visible, and some osteophytes (white arrows) are evident on the cranial acetabular margin and just proximal to the lesser trochanter.
Citation: Journal of the American Veterinary Medical Association 232, 1; 10.2460/javma.232.1.35
Ventrodorsal radiographic view of the pelvis 8 months after reduction of the right hip joint. Moderate displacement of the fracture fragment (black arrow) is visible, and some osteophytes (white arrows) are evident on the cranial acetabular margin and just proximal to the lesser trochanter.
Citation: Journal of the American Veterinary Medical Association 232, 1; 10.2460/javma.232.1.35
Ventrodorsal radiographic view of the pelvis 8 months after reduction of the right hip joint. Moderate displacement of the fracture fragment (black arrow) is visible, and some osteophytes (white arrows) are evident on the cranial acetabular margin and just proximal to the lesser trochanter.
Citation: Journal of the American Veterinary Medical Association 232, 1; 10.2460/javma.232.1.35
The dog of this report was reevaluated by the referring veterinarian 10 days after initial examination. Increased radiolucency in the previously identified femoral head fracture but no fragment displacement was detected in a VD radiographic view. The owner elected to continue conservative management, and 8 months after the accident, we reevaluated the dog. The owner reported that the dog ran 20 to 25 miles a week with only occasional stiffness noticed and received a glucosamine supplement daily. No lameness was noticed on examination, and only mild discomfort was detected on hip joint abduction and extension. At that time, mild degenerative changes and migration of the aforementioned fracture fragment were visible in a VD radiographic view of the affected hip joint (Figure 3). The fragment was displaced caudoventrally, and lack of lameness was attributed to the location of the fragment, which was caudal to the weight-bearing surface of the hip joint. The owner was counseled about degenerative arthritis and the possible need for total hip replacement or femoral head and neck ostectomy in the future.
References
- 1.↑
Simpson DJ, Lewis DD. Capital epiphyseal fractures. In: Slatter DH, ed. Textbook of small animal surgery. 3rd ed. Philadelphia: Saunders, 2003;2062–2063.
- 2.↑
Harley JD, Mack LA, Winquist RA. CT of acetabular fractures: comparison with conventional radiography. AJR Am J Roentgenol 1982;138:413–417.
- 3.↑
Moed BR, Maxey JW. Evaluation of fractures of the femoral head using the CT-directed pelvic oblique radiograph. Clin Orthop Relat Res 1993;296:161–167.
- 4.
Crawford JT, Manley PA, Adams WM. Comparison of computed tomography, tangential view radiography and conventional radiography in evaluation of canine pelvic trauma. Vet Radiol Ultrasound 2003;44:619–628.
- 5.↑
Potter HG, Montgomery KD, Heise CW, et al. MR imaging of acetabular fractures: value in detecting femoral head injury, intraarticular fragments, and sciatic nerve injury. AJR Am J Roentgenol 1994;163:881–886.
