Introduction
Amputation has been used and described as a treatment for small animals facing several limb abnormalities, including developmental deformities, traumatic injury, and neoplasia.1–5 Most patients have good to excellent functional outcomes as they adapt to their tripedalism despite concern from their owners.3 Low complication rates are reported for limb amputations, and a large majority of dogs adapt to ambulation at faster rates than owners expect.3 There are subsets of patients with orthopedic or neurologic comorbidities that are commonly excluded as candidates for amputation. The altered biomechanics involved in ambulation, including changes to ground reaction force and contact times of the remaining limbs, may predispose the remaining joints to accelerated degeneration.6 Because of this, various limb-sparing procedures have been described and boast the potential of improved mobility and quality of life.7
All limb-sparing procedures come with a substantial cost and are not without a moderate chance of complications.8–11 Such complications can include implant failure, fracture, infection, and the need for revision surgery. Unfortunately, these complications may require multiple hospitalizations, revision surgeries, and sometimes eventual amputation of the affected limb.12
Multiple limb amputations are seldom considered a viable treatment option due to concerns of quality of life for the patient, given an implied inability to ambulate. However, multiple limb amputations are performed regularly in human patients for indications such as trauma, vascular disease, and congenital abnormalities.13 While human double amputee patients have the benefits of wheelchairs and a variety of prostheses, they still need to undergo months to years of intensive physical and occupational therapy after these procedures. Prosthetic devices are frequently the central element to achieving ambulation for both unilateral and bilateral amputees.13,14 Veterinary patients have been shown to adapt to amazing physical challenges, but no published information exists discussing the outcome of double amputations in our patient population.
Given the paucity of studies analyzing outcomes of veterinary patients treated with multiple limb amputations, comparisons to other treatment approaches are difficult. The purpose of this study was to evaluate the indications for and surgical outcomes of dogs and cats that were treated with double limb amputations. The authors hypothesized that good to excellent short- and long-term outcomes can be achieved in canine and feline patients treated with double limb amputations.
Materials and Methods
Case selection criteria
The email lists of the Veterinary Society for Surgical Oncology and the Society of Veterinary Soft Tissue Surgery were queried, soliciting participation from members who performed double limb amputations on dogs and cats. Those who responded were sent a data sheet for medical record review. Institutions with which these surgeons were affiliated included teaching hospitals and private specialty and referral centers. Contribution was encouraged regardless of patient outcome. Inclusion criteria included any canine and feline patients that underwent double limb amputations with short-term follow-up available.
Medical records review
Variables extracted from patient records included species, date of birth, age at date of first and second amputation, breed, sex, weight at date of first and second amputation, and whether the 2 amputations were performed as staged procedures or during the course of the same anesthetic event. Patient comorbidities present at the time of amputations were also recorded. Information was further requested regarding each amputation procedure, including the indication for the amputation, whether each procedure was a full limb amputation (transection between the scapula and thoracic wall, or coxofemoral disarticulation of the hind limb) or partial limb amputation (location of the amputation collected), and hospitalization time (in days) from admission to discharge for each anesthetic event.
Data pertaining to outcomes of the procedure were obtained. Contributors were asked to describe function of the patient and the use of any exoprosthesis, cart, or wheelchair. This included any immediate postoperative (defined as from the conclusion of surgery to the day of discharge), short-term (defined as the period from discharge to 14 days after discharge), or long-term (defined as any complication that presented later than 14 days from discharge) complications related to all surgical procedures. Contributors were asked to report any complications, including surgical site infection, dehiscence of the surgical incision, difficulty ambulating after amputation, pain associated with the amputation site, or any other complications encountered during the follow-up period. The need for surgical revisions was also documented, as well as the reason for revision surgery, the number of revisions performed, the time from amputation surgery to the first revision surgery, and the time from the amputation surgery to the last revision surgery (if multiple revisions were reported). For patients with staged amputations, each amputation surgery was considered separately regarding complications.
Complications were categorized as major or minor. Major complications were defined as those that required revision surgery or those that led to euthanasia of the patient. Minor complications were defined as those that resolved through conservative management. Information regarding patient survival was also collected. If a patient died or was euthanized from the time of surgery to the beginning of data collection, the cause was recorded. The degree of owner satisfaction was categorized by a Likert scale as strongly dissatisfied, mildly dissatisfied, neither satisfied nor unsatisfied, mildly satisfied, or very satisfied/excellent. Owner satisfaction was noted by direct discussion with owners via phone or email communications. If owners could not be contacted, records from the last visit were reviewed for satisfaction data.
Results
Signalment
Of the 18 animals included in this study, 14 were dogs and 4 were cats. Of the 14 dogs, 4 were spayed females, 4 were neutered males, 3 were sexually intact females, and 3 were sexually intact males. These dogs included 7 mixed-breed dogs and 1 each of Bull Terrier, Pug, Miniature Poodle, Belgian Sheepdog, Doberman Pinscher, Tree Walker Coonhound, and pit bull–type dog.
Median age for all participants at first or only amputation procedure was 1.4 years (range, 0.18 to 7.2 years). For dogs with staged amputations, median age at first amputation was 1 year (range, 0.18 to 7.2 years). Median time to second amputation was 50 days (range, 3 to 832 days). Mean weight of dogs was 14.6 kg (median, 11.6 kg; range, 1.9 to 30 kg), and there was no difference in recorded weights between first and second amputations in staged patients. Mean age of dogs was 3.7 years (median, 3.4; range, 0.18 to 8.25 years).
Of the 4 cats, 2 were spayed females, 1 was a neutered male, and 1 was a sexually intact female. Three of the cats were domestic shorthairs, and 1 was a Ragdoll. Mean weight of cats was 3.8 kg (median, 4 kg; range, 3.1 to 4.14 kg), and there was no difference in recorded weights between first and second amputations in staged patients. Mean age of cats was 1.38 years (median, 1 year; range, 1 to 2.5 years).
Surgical data
Of the 18 patients, 11 had both amputations performed during the same surgical event (unstaged). The remaining 7 patients were characterized as having undergone staged procedures. Of these 7 patients, 6 had 1 limb removed at each surgical event; the other had bilateral partial limb amputations at the first surgical event and full amputation of the remaining portions of those limbs at a second event. Twelve of 18 patients underwent bilateral pelvic limb amputations (10 dogs and 2 cats), 4 underwent bilateral thoracic limb amputations (3 dogs and 1 cat), and 2 underwent 1 pelvic and 1 contralateral thoracic limb amputation (1 dog and 1 cat).
Nine of the 18 patients had bilateral partial limb amputations performed, and 9 underwent bilateral full limb amputations. Six of 14 dogs had bilateral partial limb amputations performed, and the other 8 had bilateral full limb amputations. Three of 4 cats had bilateral partial limb amputations performed, and the remaining 1 cat had bilateral full limb amputations. One of the 3 cats that was initially treated with partial limb amputations of the pelvic limbs later underwent revision surgery for full coxofemoral disarticulation as a result of short-term complications, leading to a final count of 2 cats in each group (partial vs full limb amputation). Indications for amputation were categorized as trauma (n = 12), neoplasia (1), congenital malformation (1), neurologic disease (1), chronic orthopedic complication (1), ischemic vascular disease of unidentified etiology (1; Figure 1), and chronic limb trauma due to paralysis induced by melarsomine (Immiticide) treatment for heartworm infestation (1).
Preoperative photograph of the right pelvic limb with clear demarcation of ischemia in a cat that underwent bilateral midfemoral amputations.
Citation: Journal of the American Veterinary Medical Association 260, 8; 10.2460/javma.21.04.0199
Preoperative photograph of the right pelvic limb with clear demarcation of ischemia in a cat that underwent bilateral midfemoral amputations.
Citation: Journal of the American Veterinary Medical Association 260, 8; 10.2460/javma.21.04.0199
Preoperative photograph of the right pelvic limb with clear demarcation of ischemia in a cat that underwent bilateral midfemoral amputations.
Citation: Journal of the American Veterinary Medical Association 260, 8; 10.2460/javma.21.04.0199
Median duration of hospitalization was 2 days (mean, 2.5 days; range, 1 to 10 days). The date of last known follow-up was reported for all patients. The owners of 2 of 18 patients could not be reached for current updates on patient outcome. Median time from last amputation procedure to last known follow-up was 596 days (range, 85 to 4,380 days). Five patients reportedly died during the follow-up period. Median time from bilateral or second amputation to death was 987.5 days (range, 139 to 3,905 days). Of the 5 incidents of death during the follow-up period, only 1 patient was euthanized due to complications related to the amputations. One patient, which received full limb amputations of the right thoracic and left pelvic limbs due to neoplasia, was euthanized for progressive metastatic disease. The other 3 patients were euthanized for reasons unrelated to the amputation surgery or cause.
Bilateral thoracic limb amputations
Two of the 4 patients with bilateral thoracic limb amputations underwent staged procedures in which the 2 thoracic limbs were amputated during separate surgical events. For the purpose of this study, a full limb thoracic amputation included those animals that had their scapula removed with the limb or amputations done at the level of the glenohumeral joint. This definition was chosen because a prosthetic could not be attached, and no stump remained. One animal underwent partial limb amputations, and 3 were full limb. The 1 patient with partial limb amputation had both limbs removed at the level of the midradius and ulna. This patient was not fitted for prosthetics, nor was any other type of assistance device used, but it was noted to use the thoracic stumps to rise, adjust position, and balance. Comorbidities were reported in 2 dogs that underwent bilateral thoracic limb amputations (Supplementary Table S1).
The overall complication rate for this group of patients was 50% (2/4), both of which were major complications. Revision surgery was reported for a cat that underwent surgery for skin grafting to facilitate surgical site healing at both stumps after partial limb amputation. The other patient with a major complication in this group was a full-limb-amputation patient that never adapted to use of a wheelchair or ambulation after staged full limb amputation.
Bilateral pelvic limb amputations
The 12 cases of bilateral pelvic limb amputations included 2 cats (Figure 2) and 10 dogs. Four of these patients (2 cats and 2 dogs) underwent staged procedures, and 8 (8 dogs) underwent unstaged bilateral amputations. Seven animals (5 dogs and 2 cats) had bilateral partial limb amputations, and 5 (5 dogs) had coxofemoral disarticulations. Of the 7 patients undergoing partial limb amputations, the locations of the amputations were as follows: proximal femur (1 limb), distal metatarsal (1 limb), complete metatarsophalangeal (1 limb), tarsometatarsal (1 limbs), stifle joint (2 limbs), midtibia (2 limbs), and midfemur (6 limbs). None of these patients were fitted for prosthetics, but 1 patient did use a wheelchair device. Three of the 7 patients undergoing partial limb amputation were reported to be using at least one of their pelvic stumps to rise, adjust position, and balance. Comorbidities in the bilateral pelvic-limb-amputation group were reported in 6 animals (Supplementary Table S1).
Postoperative photograph of the cat in Figure 1 after bilateral midfemoral amputations.
Citation: Journal of the American Veterinary Medical Association 260, 8; 10.2460/javma.21.04.0199
Postoperative photograph of the cat in Figure 1 after bilateral midfemoral amputations.
Citation: Journal of the American Veterinary Medical Association 260, 8; 10.2460/javma.21.04.0199
Postoperative photograph of the cat in Figure 1 after bilateral midfemoral amputations.
Citation: Journal of the American Veterinary Medical Association 260, 8; 10.2460/javma.21.04.0199
The overall complication rate for patients in this group was 25% (3/12). Minor complications were reported for 2 animals, and major complications were reported for 1 animal. Revision surgery was reported for 1 cat, which had ongoing necrosis of the stump tissue and surgical dehiscence during the short-term period. This cat underwent full coxofemoral disarticulation after conservative wound management failed. This patient used a wheelchair occasionally after the full limb amputation but preferred to ambulate without it.
Mixed forelimb and hind limb amputations
Of the 2 animals that underwent contralateral mixed-limb amputations, one underwent staged amputations, and the other underwent simultaneous amputations. Both amputations for both animals were full-limb amputations, and both animals had the right forelimb and the left hind limb removed. The 1 feline patient had a reported comorbidity of chronic anemia (Supplementary Table 1). No complications or revision surgeries were reported in this group.
Complications
Five of 18 animals had 1 or more complications reported over the course of the follow-up period (including short term and long term). Of these, 2 were cats and 3 were dogs. Of these 5 animals, 2 had minor complications (2 dogs) and 3 had major complication (1 dog and 2 cats). Of the 5 animals with 1 or more complications during the follow-up period, 4 (3 dogs and 1 cat) had reported comorbidities. Four of the 5 animals (3 dogs and 1 cat) with complications had staged amputations performed.
Immediate postoperative complications—No immediate postoperative complications were reported in any of the patients in this study.
Short-term complications—Minor complications in the short-term follow-up period were reported for 2 dogs. The first dog had staged full pelvic limb amputations as a result of self-trauma after a T12 vertebral body fracture and bilateral hip luxation led to paraparesis. Dehiscence and surgical site infection were reported in the first amputation site, which resolved through conservative management. The second dog had staged full pelvic limb amputations due to trauma. Incomplete healing of the surgical incision after the second limb amputation was reported at the first recheck at 14 days and resolved without any intervention.
Major complications in this period were reported for 2 animals (1 dog and 1 cat). The dog had staged full limb amputations of the thoracic limbs for treatment of surgical nonunion and osteomyelitis of fractures. There were no obvious surgical complications (incisions healed, no concerns with implants), but the animal suffered from an inability to ambulate and refusal to use its forelimb wheelchair. The cat had bilateral partial hind limb amputations performed because of uncharacterized vascular disease leading to ischemic injury to the pelvic limbs. Infection and surgical dehiscence at the midfemoral stumps were noted during this period (Figures 3 and 4). The cat underwent revision surgery and full coxofemoral disarticulation after conservative management failed.
Photograph of the cat in Figure 1 at 12 days after limb amputations. Necrosis of the skin and dehiscence are evident at both surgical sites.
Citation: Journal of the American Veterinary Medical Association 260, 8; 10.2460/javma.21.04.0199
Photograph of the cat in Figure 1 at 12 days after limb amputations. Necrosis of the skin and dehiscence are evident at both surgical sites.
Citation: Journal of the American Veterinary Medical Association 260, 8; 10.2460/javma.21.04.0199
Photograph of the cat in Figure 1 at 12 days after limb amputations. Necrosis of the skin and dehiscence are evident at both surgical sites.
Citation: Journal of the American Veterinary Medical Association 260, 8; 10.2460/javma.21.04.0199
Photograph of the cat in Figure 1 at 24 days after limb amputation, following wound management of necrosis and dehiscence. The left femoral stump is visible through the open incision.
Citation: Journal of the American Veterinary Medical Association 260, 8; 10.2460/javma.21.04.0199
Photograph of the cat in Figure 1 at 24 days after limb amputation, following wound management of necrosis and dehiscence. The left femoral stump is visible through the open incision.
Citation: Journal of the American Veterinary Medical Association 260, 8; 10.2460/javma.21.04.0199
Photograph of the cat in Figure 1 at 24 days after limb amputation, following wound management of necrosis and dehiscence. The left femoral stump is visible through the open incision.
Citation: Journal of the American Veterinary Medical Association 260, 8; 10.2460/javma.21.04.0199
Long-term complications—No minor complications were reported in the long-term follow-up period. Major complications were reported in 2 animals (1 dog and 1 cat). The canine patient for which long-term complications were reported was the dog reporting difficulty ambulating in the short-term follow-up period. This dog was an 8-year-old 8.5-kg Pug that underwent staged bilateral full thoracic limb amputations. The indication for the procedures had been bilateral humeral fracture nonunion and osteomyelitis, presumed to be caused by surgical site infection. The dog’s refusal to use its forelimb wheelchair continued from the short-term into the long-term follow-up period and was the eventual cause of euthanasia, as the owner felt the patient’s quality of life was poor. The cat underwent unstaged partial thoracic limb amputations after suffering electrocution injury to both thoracic limbs. Due to incomplete healing at the amputation stumps, skin grafting was performed at 39 days in one limb and at 61 days in the other. These procedures resolved the complication.
Owner satisfaction
Of the 18 patients in this study, 14 owners reported a score of very satisfied/excellent, 3 reported a score of mildly satisfied, and 1 reported a score of strongly dissatisfied. Of the 8 cases of bilateral partial limb amputations, 1 owner was mildly satisfied and the other 7 were very satisfied. Of the 10 cases of bilateral full limb amputations, 1 owner was strongly dissatisfied, 2 were mildly satisfied, and 7 were very satisfied.
Owners of 10 of the 14 dogs included in the study reported a satisfaction score of very satisfied/excellent, 3 reported a satisfaction score of mildly satisfied, and 1 reported a satisfaction score of strongly dissatisfied. Owners of all 4 cats in this study reported a satisfaction score of very satisfied/excellent.
Of the 5 cases with reported complications, 4 owners reported excellent satisfaction scores (2 cats and 2 dogs). One dog had a score of strongly dissatisfied. The patient was never able to ambulate after bilateral thoracic limb amputations.
Discussion
This study evaluated the patient outcome and owner satisfaction of double limb amputations in dogs and cats. All patients had 2 limbs amputated either partially or fully and either simultaneously or through staged procedures. Of the 14 dogs and 4 cats in this study, 1 dog and 2 cats had major complications reported, and the 2 cats required revision surgery. Seventeen of 18 owners reported being either mildly satisfied or very satisfied with the patient’s outcome, and 1 owner reported being strongly dissatisfied. While it was not a specific focus of this study, a clinical difference in outcomes between partial limb amputations and full limb amputations was not seen, as both groups had high satisfaction scores. None of the patients in this study were fitted for prosthetics, although 3 patients (2 dogs and 1 cat) were noted to have a wheelchair available to them. Even though none of the partial amputation patients used external prosthetics, 4 of these 9 patients did use their stumps for some measure of ambulation or balance. Future studies could look at long-term data on benefits and complications associated with partial limb amputations. The presented data provide evidence supporting the feasibility of double limb amputations in cats and dogs. Of the 8 cases of bilateral partial limb amputations, 1 owner was mildly satisfied and 7 owners were strongly satisfied. Of the 10 cases of bilateral full limb amputations, 1 owner was strongly dissatisfied, 2 were mildly satisfied, and 7 owners were strongly satisfied.
Trauma was the predominant indication for double limb amputation in this case series (two-thirds of cases), but various additional indications (neoplasia, congenital deformity, neurologic disease, chronic orthopedic complication, vascular disease) were represented. The vast majority achieved an excellent outcome according to owner-reported quality of life regardless of indication. Both canine and feline patients were assigned predominantly excellent satisfaction scores by their owners. The authors hypothesize that this high rate of high owner satisfaction was due to a combination of several factors. The nonambulatory state of the patients prior to amputation allowed them to adapt quickly postoperatively. The fact that all the patients were suffering from painful processes before surgery that were relieved by surgery may have also contributed to an improved patient quality of life and positive owner satisfaction. Although owner reports of satisfaction are a subjective outcome measure, owner surveys have been used to evaluate owner satisfaction with limb amputation surgery and orthopedic surgery in veterinary patients previously, and more recent work has shown the importance of these types of outcomes.15,16
When comparing cases of staged and simultaneous bilateral amputations and their associated complications, 4 of the 5 animals with reported complications underwent staged procedures. Thus, 4 of 7 patients undergoing staged amputations had complications, while 1 of 11 patients undergoing simultaneous amputations had complications. One of the patients with complications had originally undergone simultaneous partial limb amputations of both pelvic limbs as a result of uncharacterized vascular disease leading to loss of function and necrosis of the distal limbs. Infection, dehiscence, and continued necrosis of muscle in the remaining stumps led to a second surgical event in which the pelvic limb stumps were removed via coxofemoral disarticulation, yielding a cat that had underdone staged full limb pelvic limb amputation. This cat eventually had an excellent outcome according to the owner-reported quality-of-life survey and clinician follow-up exams despite these complications. Our results suggested that patients have fewer complications when undergoing simultaneous double amputations; this may have been due to a shortened recovery period and a more acute adaptation phase.
Major complications were reported for 3 of 18 animals at some point during the follow-up period. Of those 3 animals, 2 achieved excellent owner satisfaction scores after their complications were surgically addressed. As previously discussed, one of these, a cat for which partial bilateral femoral limb amputations were revised surgically to coxofemoral disarticulations due to infection and surgical dehiscence, achieved excellent owner satisfaction after revision surgery. The second feline patient underwent unstaged partial thoracic limb amputations after suffering electrocution injury to both thoracic limbs and required skin grafting to both stumps for complete healing. The third animal, an 8-year-old Pug that had undergone staged full limb bilateral thoracic limb amputations, was assigned a poor satisfaction score due to an inability to ambulate. This patient had several reported comorbidities, including hyperadrenocorticism and hip dysplasia, which may have contributed to its poor mobility and decreased quality of life after amputation. Further investigation is warranted to determine whether existing comorbidities such as orthopedic disease or endocrine disease affect a patient’s ability to reestablish successful ambulation after double limb amputation and whether such conditions predispose double limb amputees to complications such as delayed incisional healing and dehiscence/infection of the surgical site. It is also important to note that 2 of the patients in this group had partial limb amputations and 2 of the 3 had thoracic limb amputations.
In the present study, 2 of the 4 animals that underwent bilateral thoracic limb amputations reported major complications, and 1 of those required revision surgery. In a case series on thoracic and pelvic limb stump and socket prostheses, Phillips et al1 reported a similar rate of complications in 7 of 12 dogs, most of which were thoracic limb patients (6/9 complications). The authors of that study did not recommend bilateral thoracic limb stump socket prostheses because all dogs in the study with a poor outcome had a thoracic stump socket prosthesis. The reason for this high rate of complication in thoracic limb amputations could be the natural tendency to bear more weight on forelimbs, making adaptation more difficult. Animals without forelimbs either need to shift caudally to ambulate upright (Figure 5) or need to push themselves forward on the ground with their hind limbs. The 2 animals that had major complications after undergoing bilateral thoracic limb amputations were 1 and 8 years old, and the 2 that had no reported complications were 0.18 and 1 year old. All but the 8-year-old dog achieved mildly satisfied or excellent owner satisfaction scores. The 8-year-old dog, however, had poor owner satisfaction and was eventually euthanized due to a lack of mobility. It is possible that the young age of the other 3 patients allowed for a quicker adaptation to their lack of thoracic limbs and achieving satisfactory mobility. These rates of complications and need for revision were higher than for those animals that had bilateral pelvic limb amputations, but the small sample size of this thoracic limb group precludes conclusions on this procedure’s suitability as a viable treatment choice.
Photograph of a dog after bilateral thoracic limb amputations. This dog adapted to weight bearing and ambulation solely using its pelvic limbs.
Citation: Journal of the American Veterinary Medical Association 260, 8; 10.2460/javma.21.04.0199
Photograph of a dog after bilateral thoracic limb amputations. This dog adapted to weight bearing and ambulation solely using its pelvic limbs.
Citation: Journal of the American Veterinary Medical Association 260, 8; 10.2460/javma.21.04.0199
Photograph of a dog after bilateral thoracic limb amputations. This dog adapted to weight bearing and ambulation solely using its pelvic limbs.
Citation: Journal of the American Veterinary Medical Association 260, 8; 10.2460/javma.21.04.0199
While complications did occur in the present case series, the rate was consistent or lower than in other studies presenting surgical options for patients with severe orthopedic disease. In a review of limb salvage surgery for osteosarcoma of the proximal humerus in 19 dogs, Kuntz et al8 reported that 41% eventually required amputations for their postoperative complications. Of the 10 dogs that did not require amputations for postoperative complications, 9 had poor or fair ultimate function in their limbs. Wustefeld-Janssens et al12 analyzed the outcome of dogs requiring limb amputation as an end point for managing complications related to limb salvage surgery for appendicular osteosarcoma. The authors reported a 16% absolute risk of requiring amputation after limb salvage surgery; the complications from the limb salvage procedure that led to amputation included surgical site infection, ischemic injury, mechanical failure, and local recurrence of osteosarcoma.12
Complications that could be especially difficult to manage in the present case series would include incisional complications because of an inability to protect the incisions from weight bearing or friction. These complications were anticipated and observed and should be discussed with owners before undertaking these procedures. Delayed healing was seen in 2 of 18 patients but did not affect owner-perceived outcome. Surgical site infection was also reported in 2 of 18 patients, which is a rate similar to that reported in a review of wound complications after limb amputations in cats and dogs.17 In that review, the authors reported inflammation complications in 20.9% and infection complications in 9% of animals and found no significant difference in rates of infection between canine and feline amputees. The authors attributed the infection rate to several factors, including prolonged anesthesia time, extensive surgical trauma, manipulation of soft tissue at the amputation site, and the typically recumbent position of the animal in the postoperative period. In cases of double limb amputations, these same contributing factors may also be contributing factors to infection rates. Another possible complication with these patients could be phantom-limb pain. While this has been anecdotally reported,2 none of the owners or veterinarians contacted reported any clinical signs consistent with this type of complication.
Careful case selection requiring a review of existing comorbidities and discussion with owners about potential complications will allow for both canine and feline patients to be successfully treated with amputation of multiple limbs with an excellent quality of life. Subjectively, patients with evidence of certain comorbidities, including concurrent orthopedic disease in their remaining limbs, may be poor candidates for multiple limb amputations. The severity of the orthopedic disease should be considered, not just its presence. Eight of the 9 patients with reported comorbidities in the present study reported good to excellent owner satisfaction, and the comorbidities varied, including endocrinopathies, orthopedic disease, and others. The 1 patient with a poor owner satisfaction score had preexisting orthopedic disease in both pelvic limbs prior to the amputation of both thoracic limbs. The second case with reported orthopedic disease in the pelvic limbs as a comorbidity still achieved a good owner satisfaction after bilateral thoracic limb amputations. We surmise that the differences between these 2 cases, namely the older age and further progression of the orthopedic disease in the former patient, were contributing factors to the stark difference in patient outcome.
Another important point regarding case selection includes location of amputations, with pelvic limb amputees reporting fewer complications (50% vs 25%) than thoracic limb amputees. This could be explained by the disparity in case numbers or the known differences between weight bearing in animals. Other considerations include the age of the patient, size of the patient, and length of time patients have been experiencing symptoms from their primary disease process. The majority of our patients were younger with a mean age < 4 years for dogs and < 2 years for cats. This could absolutely be an advantage with regards to adaptation. Our patients were also generally small, with a median weight for dogs of 11.6 kg and no dogs heavier than 30 kg. It would be completely reasonable to assume that large- and giant-breed dogs would have a more difficult time adapting to amputation, compared with a small-breed dog. We were unable to determine the length of time that patients were affected before amputation, but this would be interesting data in a prospective study.
Limitations to the present study included the retrospective nature of the study and an overall small sample size, in particular small sample sizes of feline patients and bilateral thoracic limb amputees, and variations in surgical technique. Surgical techniques for multiple limb amputation in this study ranged from full limb disarticulation to partial limb amputation, and even within those descriptions a variety of osteotomies (transverse/obliques), deep tissue closures (muscle coverage patterns), and skin closures (primary suturing vs digital pad grafting) could have been performed. One of the authors pays close attention to the direction of the limb and typical weight bearing in planning the direction of osteotomy when performing a mid to distal limb amputation, while the other authors tend to routinely recommend full limb amputations. These surgical technique variations can affect outcome, and prospective studies should evaluate these differences. Response bias may have affected reported owner satisfaction scores, as our experience suggests that clients generally want to feel good about proceeding with procedures, and this procedure in particular could seem socially unacceptable to the community at large. Selection bias may have also played a role if only surgeons with positive outcomes responded to our survey. The data were retrieved by survey of 2 large societies, but increasing the survey respondents to nonspecialists or orthopedic groups could have led to higher numbers and possibly changed the results. Further research is required to determine whether variables such as species, age, weight, indication for amputation, and limb location are statistically predictive of need for revision surgery, patient outcome, and owner satisfaction.
In conclusion, the authors believe that patients suffering multiple limb injuries, especially pelvic limbs, that can undergo simultaneous amputations can have an excellent outcome. In cases of financial constraint or severe limb disfigurement, double limb amputations may be a viable alternative to endo- and exoprostheses in achieving ambulation and restoring quality of life without increased complication risk.
Supplementary Materials
Supplementary materials are posted online at the journal website: avmajournals.avma.org
Acknowledgments
No third-party funding or support was received in connection with this study or the writing or publication of the manuscript. The authors declare that there were no conflicts of interest.
References
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