Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2016 Mar;18(3):203-18.
doi: 10.1177/1098612X16631227.

Feline hip dysplasia: A challenge to recognise and treat

Karen Perry  1
Affiliations
Review

Feline hip dysplasia: A challenge to recognise and treat

Karen Perry. J Feline Med Surg. 2016 Mar.

Abstract

Practical relevance: The reported incidence of hip dysplasia (HD) in cats varies dramatically between studies, but the condition is likely more common than we realise. There is little doubt that cats with HD and associated osteoarthritis (OA) suffer pain, and this warrants appropriate therapy.

Diagnostic challenges: Clinical signs of HD in cats are often gradual in onset, making them difficult to appreciate, but may include inactivity, pelvic limb lameness, difficulty jumping and climbing stairs, and reluctance to squat to defecate. Often lameness is bilateral, and can be particularly difficult to recognise. The most common radiographic finding is an abnormally shallow acetabulum. Subluxation, however, is not consistently associated with OA in cats and therefore the role that joint laxity plays in disease progression remains uncertain. Degenerative changes of the femoral head and neck seem to develop later than in the dog, and are less marked.

Therapeutic challenges: The majority of cats respond to non-surgical management with environmental modulation, physical therapy, dietary modulation, weight loss, nutraceuticals and drug therapy. Should non-surgical management not provide sufficient relief, two salvage surgical options are available: femoral head and neck excision (FHNE) and total hip replacement (THR). While there is a risk of complications with micro-THR, the positive outcomes that have been reported indicate that it should be considered in the treatment of coxofemoral pathology in cats in the same way that THR is considered for larger dogs, especially given the inconsistent results associated with FHNE. Monitoring the effect of treatment is challenging as the assessment of pain in cats is complex and there is no validated scoring system or owner-completed questionnaire yet available for cats.

Evidence base: There is a paucity of clinical reports focusing solely on HD in cats. The author draws on a combination of published studies, in cats, dogs and humans, as well as personal clinical experience.

PubMed Disclaimer

Conflict of interest statement

The author declared no potential conflicts of interest with respect to the research, authorship and/or publication of this article.

Figures

Figure 1
Figure 1
Ventrodorsal (a) and lateral (b) radiographs of a 7-year-old female domestic shorthair cat that presented for investigation of bilateral pelvic limb lameness. Bilateral medial patellar luxation had been surgically addressed 6 years earlier. A bilateral stiff and stilted gait was noted, with pain on manipulation and reduced range of motion affecting both hips. Both patellae were stable and there was no pain upon stifle manipulation. The radiographs reveal moderate bilateral coxofemoral osteoarthritis (OA) with decreased acetabular coverage of both femoral heads and irregularly marginated shallow acetabulae with osteophytes present along the cranial and caudal margins. A large osteophyte is also present along the caudal margin of the left acetabulum
Figure 2
Figure 2
Limits of abduction (a) and extension (b) in a domestic shorthair cat
Figure 3
Figure 3
Ventrodorsal radiograph of the pelvis of a cat demonstrating the technique required to measure the Norberg angle. The circles that best fit the outlines of the femoral heads have been drawn in magenta and a line connecting the centers of these two circles has been drawn in yellow. A line has been drawn between the cranial acetabular edge and the center of the respective femoral head in blue. The angle between the blue and yellow lines is the Norberg angle (99° in this case)
Figure 4
Figure 4
Ventrodorsal radiograph of the pelvis of a cat demonstrating the technique required to measure the distraction index. The circle that best fits the outline of the acetabulum has been drawn in blue and the circle that best fits the outline of the femoral head has been drawn in magenta. The distraction index is calculated by dividing the distance between the center of the femoral head and the geometric center of the acetabulum (1.2 mm as indicated by the yellow line in this figure) by the radius of the femoral head (4.5 mm as indicated by the green line in this figure). So, this cat has a distraction index of 0.27. (Note, however, that this is not a compression or distraction view and thus may not be representative of the true value)
Figure 5
Figure 5
Ventrodorsal radiograph of a 13-year-old domestic shorthair cat that presented for assessment of left pelvic limb lameness. Gait assessment revealed a left hip hike. On orthopedic examination a mild pain response and crepitus were evident upon extension of the coxofemoral joints. The radiograph reveals mild bilateral coxofemoral OA (worse on the left than on the right), with small osteophytes and moderate sclerosis on the left and right acetabular margins
Figure 6
Figure 6
Ventrodorsal (a) and lateral (b) radiographs of a 13-year-old male domestic shorthair cat that presented with an unsteady pelvic limb gait and right pelvic limb lameness. The radiographs demonstrate marked right coxofemoral OA and subluxation. There is moderate rotation on the ventrodorsal view, as evidenced by the asymmetric obturator foramina, and this may affect interpretation. The femoral head is mushroom-shaped with an irregular margin and the femoral neck is shortened as well as markedly thickened. The acetabulum is shallow, irregularly shaped and has marked periarticular new bone formation on the cranial and caudal aspects of the rim. Thickening and subchondral sclerosis are evident on the medial aspect of the right acetabulum. There is an irregularly shaped, smooth margined, crescent-shaped, possibly separate mineral opacity cranial to the greater trochanter on the ventrodorsal view, and multiple rounded, separate mineral opacities caudal to the femur
Figure 7
Figure 7
Ventrodorsal (a) and lateral (b) radiographs of a 14-year-old male domestic shorthair cat that presented with difficulty ambulating on the left pelvic limb. Gait assessment demonstrated a very stiff and stilted gait bilaterally, and there was mild discomfort upon full hip extension and palpation over the caudal lumbar spine. There were no neurologic deficits. The radiographs demonstrate evidence of L7–S1 chronic intervertebral disc disease with spondylosis deformans at the lumbosacral junction; a significant lateralized component to the left is seen on the ventrodorsal view. The L7–S1 disc space is narrow and the adjacent vertebral end plates are moderately sclerotic. The increased lucency of the left ilial wing relative to the right is likely due to superimposition of gas in the descending colon
Figure 8
Figure 8
Ventrodorsal (a) and lateral (b) views of a 4-year-old male domestic shorthair cat that had bilateral FHNE performed 2 years earlier for treatment of HD and associated OA. Pelvic limb lameness and demeanor had improved following this but the cat remained unable to jump, muscle atrophy was evident and a moderate pain response persisted upon full extension or abduction of the hips. The radiographs reveal mild bilateral acetabular and proximal femoral degenerative change. An irregular bony protuberance is evident at the ostectomy edge on the right, but whether this was due to inappropriate ostectomy initially or subsequent remodeling is unknown. Otherwise the ostectomies have been performed appropriately, with the absence of femoral heads and necks and the presence of greater and lesser trochanters bilaterally. The proximal femora are sclerotic and the acetabulae are shallow bilaterally
Figure 9
Figure 9
Ventrodorsal (a) and lateral (b) radiographs of a 2-year-old British Shorthair cat 6 weeks following THR on the right for treatment of hip dysplasia and associated discomfort. Surgery was performed using a 12 mm acetabular prosthesis and a size 3 femoral stem
None
None
None
None
None
None
None
None
None
None
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Clarke SP, Mellor D, Clements DN, et al.. Prevalence of radiographic signs of degenerative joint disease in a hospital population of cats. Vet Rec 2005; 157: 793–799. - PubMed
    1. Witte PG, Scott HW, Tonzing MA. Preliminary results of five feline total hip replacements. J Small Anim Pract 2010; 51: 397–402. - PubMed
    1. Keller GG, Reed AL, Lattimer JC, et al.. Hip dysplasia: a feline population study. Vet Radiol Ultrasound 1999; 40: 460–464. - PubMed
    1. Langenbach A, Green P, Giger U, et al.. Relationship between degenerative joint disease and hip joint laxity by use of distraction index and Norberg angle measurements in a group of cats. J Am Vet Med Assoc 1998; 213: 1439–1443. - PubMed
    1. Peiffer RL, Jr, Young WO, Jr, Blevins WE. Hip dysplasia and pectineus resection in the cat. Feline Pract 1974; 4: 40–43.

LinkOut - more resources