P. 585

N. Fitzpatrick1
1Fitzpatrick Referrals, Eashing, Surrey, UK
Many dogs and cats will sustain good quality of life with appropriate and judicious plan for exercise, bodyweight management, supplementation, oral medication and rehabilitation modalities. However, there are instances where partial or complete joint replacement can be a good option for individual patients. Total hip replacement is now commonplace and commonly sought by families of both large and small dogs of all ages and also cats. Total knee replacement and total or partial elbow replacement are more recently commercially available. Implants are now emerging for partial or complete replacement of many joints. The emergence of new technologies in 3D printing and bone, tendon or skin on-growth metals has ushered a new era of personalised implants for joint replacement. Attitudes are changing within the veterinary profession regarding offering
these options to clients for canine and feline patients and clients are very much aware of these options from digital and other visual media. Increasingly clients ask for options when faced with conditions for their dogs and cats that may have traditionally been treated by excision arthroplasty, arthrodesis or full limb amputation. Most dogs and cats can have an excellent quality of life on three legs or with selected arthrodeses, but there
are circumstances where joint preservation may yield superior quality of life.
We must place special emphasis on the moral and ethical implications of the application of new technologies in clinical patients and explain all other options as well. The procedure must be in the welfare interests of the patient if other options are suboptimal but conversely,
we have an increasing responsibility as a profession to offer clients all of the options to enable fully informed consent. Evidence of ef cacy for personalised implants
is emerging for veterinary and human patients, and when conventional options are limited, increasingly clients seek alternatives. Outcomes of surgical intervention using new implants of any kind, for routine or advanced procedures, should be subject to consistent vigilant scrutiny. It should also be noted that the development and implementation of many of the implants discussed in this lecture require signi cant resource in terms of engineers and machinists and this may limit availability.
Focal resurfacing:
When focal bone and cartilage loss is a cause of lameness, pain and debilitation, focal resurfacing implants can be employed. These can include commercially available biphasic polyurethane  llers on a trabecular metal base (SynACARTTM), custom devices made of poly ether ether ketone (PEEK), and custom devices made of titanium and cobalt chrome. These devices can be employed for treatment of focal joint lesions of developmental (osteochondritis dissecans)
or traumatic origin in multiple joints. More recently personalised biphasic implants of trabecular metal and polylactide seeded with stem cells aim to recapitulate endogenous joint surfaces.
Coxofemoral Joint:
Total hip replacement (THR) is now a routine option for the treatment of end stage arthrosis of the coxofemoral joint in dogs and cats. Potential patients historically precluded by virtue of age or size are no longer excluded from this intervention if deemed clinically appropriate. Juvenile dogs under a year of age and small dogs
under 5kg are now routinely operated, as are cats. Both cemented and biologic ingrowth implants are available, the procedure is standardised and reproducible and with a low complication rate.
Reported complications after femoral head and neck excision (FHNE) include ongoing lameness associated with limb shortening, patellar luxation, sciatic neuropraxia and  brous adhesions, and limitation in range of hip motion accompanied by severe muscle atrophy and
pain associated with  brous adhesions. It has been shown that dogs never achieve full peek vertical impulse following FHNE by comparison with THR. Revision of FHNE to THR has been reported in dogs and cats with positive outcomes but should not be a  rst choice. In such cases and also in cases of revision of previously failed THR, there can be notable de cits of the proximo- medial aspect of the femur. This can be compensated using a reinforcing stem collar foundation linked to the greater trochanter for added resistance to fracture.
Bone de cits of the acetabulum or femur can present signi cant surgical challenges. The simplest options
for managing dorsal acetabular rim (DAR) insuf ciency during total hip replacement include implantation of a relatively small diameter cup, recessing a non-cemented cup into the medial acetabulum, leaving a portion of
the cup exposed laterally, and moving the acetabular component further cranially into the caudal ilium and applying a longer neck length. Plates and cement in conjunction with a cemented cup may also be used to augment a paucity of dorsal acetabular rim. However, these methods may be susceptible to complications
An Urban Experience

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