Abstract
Treatment and outcome of camelids with long-bone fractures are described. Medical records (1998–2008) of camelids (n = 28) with long-bone fractures were reviewed for signalment, time to presentation, fracture type, method of repair, duration of hospitalization, and post-operative complications. Follow-up information was obtained via telephone interviews with owners. Mean age and weight at presentation were 3.4 years and 56.3 kg, respectively. Twenty-six fractures were treated with internal fixation (n = 11), external fixation (n = 10), combination of internal and external fixation (n = 3), amputation (n = 1), and external fixation followed by amputation (n = 1). Long-term follow-up information was obtained for 19 of the 26 animals. The post-operative complication rate was 23% and owner satisfaction was high. Animals with open fractures were more likely to experience complications. Internal fixation was associated with superior alignment and outcome. Internal fixation techniques should be recommended for camelids.
Résumé
Fractures des os longs chez les lamas et les alpagas : 28 cas (1998–2008). Le traitement et les résultats obtenus chez les camélidés avec des fractures des os longs sont décrits. Les dossiers médicaux (1998–2008) de camélidés (n = 28) avec des fractures des os longs ont été examinés pour le signalement, le moment de la présentation, le type de fracture, la méthode de réparation, la durée de l’hospitalisation et les complications postopératoires. Des renseignements de suivi ont été obtenus lors d’entrevues téléphoniques avec les propriétaires. L’âge et le poids moyens à la présentation étaient de 3,4 ans et de 56,3 kg, respectivement. Vingt-six fractures ont été traitées à l’aide d’une fixation interne (n = 11), d’une fixation externe (n = 10), d’une combinaison d’une fixation interne et externe (n = 3), d’une amputation (n = 1) et d’une fixation externe suivie d’une amputation (n = 1). Des renseignements de suivi à long terme ont été obtenus pour 19 des 26 animaux. Le taux de complication postopératoire était de 23 % et la satisfaction des propriétaires était élevée. Il était plus probable que les animaux avec une fracture ouverte éprouvent des complications. La fixation interne était associée à un alignement et à des résultats supérieurs. Les techniques de fixation interne devraient être recommandées pour les camélidés.
(Traduit par Isabelle Vallières)
Introduction
Unlike horses and large ruminants, llamas and alpacas are excellent candidates for repair of long-bone fractures. A quiet temperament, relatively small body size, ability to bear weight on 3 limbs during convalescence, and stoic nature allow these animals to respond well to surgical repair of long-bone fractures (1). The economic importance of these species in general and the specific financial value of individual animals often motivate owners to pursue recommended treatment for their animals (2). Llamas and alpacas are typically used for fiber, breeding, kept as pets, show animals, guard animals, or pack animals. The individual’s conformation, fiber quality, and temperament will dictate the intended use. Chronic pain, lameness, or altered conformation may affect the animal’s ability to return to its intended use after a long-bone fracture. Understanding the optimal treatment and likely long-term outcome of a given orthopedic injury will help owners and veterinarians make informed decisions regarding the care of these animals.
Relatively few studies have reviewed a large number of cases in order to evaluate current treatment and outcome of long-bone fractures in llamas and alpacas. Reported treatment options include internal fixation using a combination of lag screw and plating techniques, transfixation pin casts, casting alone, heavy bandaging with or without splinting, external skeletal fixation (ESF) devices, amputation, and stall rest (3–6). Several case reports have focused on either treatment of specific bones or specific fracture repair techniques (3–5,7–9). These reports suggest that llamas and alpacas do well with internal fixation of long-bone fractures, and that owner satisfaction with outcome and return to performance is high (9,10). However, in 2008, Semovolos et al (11) reported complication rates as high as 87% following orthopedic surgery in 24 camelids. Complications included chronic lameness, joint hyperextension, osteoarthritis, delayed fracture healing, decreased range of motion, peripheral nerve injury, and implant failure (11). In a more recent study reporting on the outcome of 28 camelids treated for long-bone fractures, major complications were encountered in 8 (29%) animals (12). In light of the conflicting results of these recent reports, additional studies evaluating a number of different fracture types and treatment options would help provide additional information on prognosis for these cases.
The objective of this study, therefore, is to report the treatment, management, and short- and long-term outcomes of long-bone fractures in llamas and alpacas presented to our hospital. We hypothesized that animals with closed fractures and fractures repaired using internal fixation techniques would have a more favorable prognosis for return to function than animals with open fractures and those treated with external coaptation.
Materials and methods
Medical records of all llamas and alpacas admitted between January 1998 and December 2008 were reviewed. Llamas and alpacas with a radiographic diagnosis of long-bone fracture were included. Data retrieved included signalment (age, weight, gender, species); duration of time from onset of clinical signs to presentation; bone fractured; fracture configuration (simple, comminuted); whether the fracture was open or closed; treatment type [open reduction and internal fixation (ORIF), transfixation pin cast, cast, splint, bandage, or amputation]; duration of hospital stay; number of follow-up visits; postoperative complications; and short-term outcome. Post-operative complication was defined as a major post-operative event that required surgical revision or alteration of the treatment plan.
Long-term outcome (return to function) and overall owner’s satisfaction were determined by telephone interviews with the owner between 1 and 11 y following discharge. Owners of animals discharged from the hospital were contacted by telephone and asked a standardized set of questions to assess perceived post-operative progress, presence or resolution of post-operative complications, return to expected function, and overall owner satisfaction. Based on information regarding outcome measures of reduced function obtained from owners, animals were given an outcome score and placed into 1 of 4 groups (Group 1 — return to intended use, no post-operative complications or long-term reduced function; Group 2 — return to intended use, minor post-operative complications or long-term reduced function; Group 3 — functionally recovered, but did not return to intended use due to post-operative complications or long-term reduced function; Group 4 — euthanized or died due to post-operative complications or long-term reduced function related to fracture).
Descriptive statistics presented as range (mean ± standard deviation and median) were used to summarize the results. Fisher’s exact test was used to evaluate return to function (Group 1 and Group 2) or failure to return to function (Group 3 and Group 4) in fractures repaired using internal and external fixation techniques, as well as open and closed fractures. A t-test for means was used to compare outcome scores (Group 1–4) for the 6 different bones represented in this study. Values of P ≤ 0.05 were considered statistically significant.
Results
Animals
Twenty-eight camelids were included in the study: 8 llamas and 20 alpacas. The 8 llamas consisted of 4 females, 1 castrated male, and 3 intact males. The 20 alpacas included 11 females and 9 intact males. Age ranged from 1 mo to 18 y [mean ± standard deviation (SD): 3.4 ± 4.7 y; median: 1.5 y] and weight ranged from 14 to 159 kg (56.3 ± 41.4 kg; 44.85 kg).
History and clinical evaluation
The duration of time from onset of clinical signs and presentation to the hospital ranged from a 3.5 h to 56 d (4.1 ± 11.3 d; 3 d). Diagnosis of fracture was made by clinical evaluation as well as radiographic findings and included fractures of the radius/ulna, 9 (32%); metacarpus, 5 (18%); tibia, 5 (18%); femur, 4 (14%); metatarsus, 4 (14%); and humerus, 1 (4%). Of the 28 fractures, 18 (64%) were closed and 10 (36%) were open, of which 2 radial, 1 metatarsal, 1 femur, and 3 metacarpal fractures were open.
Treatment
Twenty-six fractures were treated with a variety of techniques including internal fixation (n = 11), external fixation (n = 5), external coaptation (n = 5), a combination of internal fixation and external coaptation (n = 3), amputation (n = 1), and external fixation followed by amputation due to infection and non-union (n = 1). One animal was discharged without treatment and subsequently euthanized at a follow-up visit due to osteomyelitis, while another animal was euthanized without treatment during the initial visit due to the severity of the fracture and financial constraints. Overall, internal fixation techniques used included intramedullary (IM) pin with cerclage wires (n = 3), locking compression plate (LCP) (n = 2), narrow dynamic compression plate (nDCP) alone (n = 1), nDCP with lag screws (n = 2), Steinman pin with cerclage wires (n = 2), and transphyseal Kirschner wire pinning with figure of 8 wires (n = 1). External coaptation techniques included transfixation pin cast (weight-bearing casts with pins proximal to the fracture or type II transfixation with pins proximal and distal to the fracture) (n = 5), bandage alone (n = 3), cast alone (n = 1), and cast bandage (n = 1). Techniques combining internal fixation and external coaptation included a dynamic compression plate, lag screws, and cast (n = 2). The third animal that received a combination of internal and external fixation techniques had 3 surgical procedures. The first repair used a narrow locking compression plate and autogenous bone graft followed by plate removal and application of a cast 14 mo later due to sequestrum formation and a draining tract. Three months after cast application (17 mo after initial repair), a second bone graft and transfixation pin cast were used to successfully treat an established non-union.
Eight of the 9 animals with radial fractures were treated. Repair included nDCP with lag screws (n = 2), nDCP alone (n = 1), DCP with lag screws and a cast (n = 1), Steinman pin and cerclage wires (n = 1), bandage (n = 2), and cast (n = 1). All 5 animals with metacarpal fractures were treated. Fixation techniques included transfixation pin cast (n = 3), amputation (n = 1), and a series of repairs involving nLCP, bone grafts, a tube cast, and a transfixation pin cast (n = 1). The last of these was a young male with an open, comminuted, highly contaminated, articular, displaced, proximal metacarpal fracture. Follow-up radiographs documented sequestrum formation, osteopenia, and non-union. Chronic swelling and drainage from the site necessitated plate removal and subsequent fixation with a tube cast followed by transfixation pin cast including bone grafts and pinning from the distal radius to mid metacarpal. Concurrent prolonged treatment with appropriate antibiotics was initiated. The only long-term complication noted was limb length disparity 18 mo after the initial repair.
The 5 tibial fractures were repaired with transfixation pin cast (n = 2) (Figure 1G–J), IM pin (n = 1), LCP (n = 1), and DCP with lag screws (n = 1). Repair techniques used for the 4 metatarsal fractures included cast bandage (n = 1), bandage (n = 1), cast followed by amputation due to infection and non-union (n = 1), and LCP (n = 1) (Figure 1C–F). Three of the 4 animals with femoral fractures were treated. Repair included IM pins and cerclage wires (n = 2), and transphyseal pins and figure of eight wires (n = 1). The animal with the humeral fracture was treated by use of Steinman pins and cerclage wire (Figure 1A–B).
Figure 1.
Examples of surgical repair techniques
A — Comminuted diaphyseal fracture of the humerus
B — 8 week postoperative radiographs following repair with two intramedullary pins and multiple cerclage wires.
C,D — Dorso-plantar and lateral-medial views of a comminuted mid-diaphyseal metatarsal fracture
E — Postoperative radiograph following repair with a single locking compression plate (LCP)
F — 1 month follow-up radiographs showing excellent progressive healing
G,H — Medial-lateral and cranial-caudal views of a comminuted diaphyseal and distal metaphyseal tibial fracture.
I,J — 2 month follow-up radiographs following treatment in a transfixation cast. Although this case might ideally have been treated with ORIF, it was successfully managed with different diameter positive profile threaded transfixation pins.
I,J — 2 month follow-up radiographs following treatment in a transfixation cast. Although this case might ideally have been treated with ORIF, it was successfully managed with different diameter positive profile threaded transfixation pins.
Animals with fractures treated with amputation included alpacas with a metacarpal and a metatarsal fracture, respectively. The metacarpal fracture was observed in a 12-year-old female with an open, comminuted, articular fracture with vascular compromise. Her previous history of infertility made her a less valuable animal, and amputation was elected by the owner. The animal treated for a metatarsal fracture was a 1-month-old male with an open, comminuted, displaced fracture initially treated with a cast after angiography confirmed a viable blood supply. Four weeks after cast application, the fracture was noted to be unstable with purulent discharge and amputation was elected.
Complications
Of the 26 animals treated, 6 experienced post-operative complications, giving an overall complication rate of 23% for this population (Table 1). Three of those 6 animals had 2 complications each. The complications included implant failure or pin loosening that led to surgical revision, delayed union, malunion or non-union, infection or osteomyelitis, and sequestrum formation. Table 1 summarizes the frequency and distribution of postoperative complications for each affected bone and repair type.
Table 1.
Frequency and distribution of post-operative complications observed in 6 of 26 treated animals
| Complication | Number affected | Bone | Repair | Outcome score |
|---|---|---|---|---|
| Implant failure, pin loosening | 2 | Tibia | ORIFa, cast | 3 |
| Tibia | TPCb | 3 | ||
| Delayed union, malunion, non-union | 3 | MTc | Cast | 2 |
| MT | Cast, followed by amputation | 3 | ||
| MCd | ORIF, tube cast, TPC | 2 | ||
| Infection, osteomyelitis | 3 | Femur | ORIF | 4 |
| MT | Cast, followed by amputation | 3 | ||
| MC | ORIF, tube cast, TPC | 2 | ||
| Sequestrum formation | 1 | MC | ORIF, tube cast, TPC | 2 |
ORIF — open reduction internal fixation.
TPC — transfixation pin cast.
MT — metatarsus.
MC — metacarpus.
Short-term outcome
Hospitalization ranged from 1 to 60 d (11.7 ± 13 d; 7 d). Twenty-seven of 28 animals were discharged following their first admission, including 1 animal discharged without treatment. One animal was euthanized in the hospital on the day of presentation. Of the 26 animals treated and discharged, 2 were subsequently euthanized. One animal was euthanized 2 mo following discharge due to an unrelated illness while the other was euthanized due to development of osteomyelitis following repair of a complete, comminuted, displaced, mid-diaphyseal femoral fracture. The patient underwent internal fixation using an intramedullary pin and cerclage wires. After 6 wk, there was purulent discharge from the surgical site and increased lameness. Radiographs confirmed lytic and proliferative lesions consistent with the clinical diagnosis of osteomyelitis.
Long-term outcome and comparisons
Follow-up information was obtained for 19 of the 26 (73%) treated animals via telephone conversation with the owners between 1 and 11 y after discharge from the hospital. Seven animals were lost to follow-up. Of the 19 animals available to long-term follow-up, 8 were classified in Group 1 (42%), 3 in Group 2 (16%), 6 in Group 3 (32%), and 2 in Group 4 (11%). Overall, 11 animals (58%) returned to function (Groups 1 and 2), while 8 animals (42%) did not (Groups 3 and 4).
Outcome measures of reduced function were evaluated for animals with fractures repaired using internal and external fixation techniques. Group 1 contained 8 individuals, 6 (75%) of which were treated with internal fixation techniques. Groups 2, 3, and 4 each had 33% (1/3, 2/6, 1/3, respectively) of fractures repaired using internal fixation techniques. A significantly greater number of animals treated by ORIF were found to return to function compared with those treated with external coaptation (P < 0.0001).
Outcome measures of reduced function were compared between animals with open and closed fractures. Group 1 had 2/8 (25%) open fractures, followed by 1/3 (33%) in Group 2, 3/6 (50%) in Group 3, and 3/5 (60%) in Group 4. A significantly greater number of animals with closed fractures returned to function compared to those with open fractures (P < 0.0001).
Eight of the 9 animals presenting with radius/ulna fractures were treated and subsequently discharged. One animal was euthanized without treatment. Follow-up information was obtained for 6 (75%) of the 8, giving a mean outcome score of 1 for this group. Fractures of the radius/ulna had significantly lower outcome scores when compared to fractures of the tibia (P = 0.04), metacarpus (P = 0.008), and femur (P = 0.03). Of the 5 animals treated for fractures of the metacarpus, all were discharged and follow-up information was obtained for 4 of these animals. The mean outcome score was 3 for this group. All 5 animals treated for tibial fractures were discharged from the hospital and long-term follow-up information was obtained on 4 of the 5. The mean outcome score for animals with tibial fractures was 2.25. Metatarsal fractures occurred in 4 (14%) of the animals in this population. All 4 were discharged and follow-up information was available for 2 of these patients. The mean outcome score was 2.5. Of the 3 animals treated for femoral fractures, all were discharged and follow-up information was available for all animals giving a mean outcome score of 3. One of the animals treated (IM pin and cerclage wires) was euthanized at follow-up visit due to osteomyelitis. The animal treated for a humeral fracture was discharged and was given an outcome score of 1 at long-term follow-up.
Discussion
Camelids in this study population showed a slightly different distribution of types of fractures than those described in other reports (2,10). A previous review of 38 fractures in llamas and alpacas noted the humerus to be the bone most commonly diagnosed with fracture (15.8%), with radius/ulna being the least common of the long-bones (10.5%) (2). This same review describes the recent literature as showing that fractures of the metacarpus/metatarsal were the most common (28.7%) followed by fractures of the humerus (21.4%), radius/ulna (21.4%), femur (21.4%), and tibia (7%) (2). The low representation of humeral fractures in our study population may be the result of chance or case selection bias if there are fewer breeding males in the surrounding area. Inter-male aggression can be ferocious and includes biting, charging, rearing, striking, and chest butting (13). This head-on fighting often results in significant injuries including fractures of the humerus (13).
The 28 animals in this population had a mean age of 3.4 y; however, 19 of the 28 animals (68%) were younger than 2 y at the time of presentation. This is consistent with previous reports in the literature which demonstrate a predisposition for young animals to present with traumatic fractures of long bones (2,10).
Statistical analysis of the data demonstrated that fractures repaired using internal fixation had a better chance of return to function. The data also indicated that open fractures had a poorer prognosis for return to function than did closed fractures. Fractures of the radius/ulna had the lowest outcome score of 1, which was statistically significant, compared to the outcome scores of tibial, metacarpal, and femoral fractures. This may be explained, at least in part, by the fact that all radial fractures in this report were closed. It is suspected that greater soft tissue protection and thus better blood supply around the radius compared with the metacarpus may help contribute to the more favorable outcomes observed. Also, there was a selection bias in our hospital with simple metacarpal and metatarsal fractures being less likely to be referred.
The complication rate for animals treated with long-bone fractures, and for which follow-up information was available in this population was 23%, which is comparable to complication rates reported in some of the previous retrospective studies on long-bone fractures in camelids (6,10). However, a review of complications after fracture repair in 24 camelids showed a complication rate of 87% (11) and a recent retrospective study reported a complication rate of 42% (12). This discrepancy in reported complication rates is likely a result of different numbers of reviewed cases and variation in the inclusion criteria for defined complications. The current study includes only serious complications that required further surgical revision or alteration of the treatment plan. The study by Semevolos et al (11) included all minor and major complications that occurred following surgery. Additionally, available long-term follow-up information may differ greatly between reviewed cases. Complications observed in the treated animals in this study included osteomyelitis and infection necessitating implant removal; additional fixation; amputation; euthanasia; and nerve, joint, and soft tissue damage often leading to reduced function, most commonly chronic lameness or abnormal gait. However, most complications noted in these cases were manageable and owner satisfaction with outcomes was generally high.
The alpacas treated with amputation were intended for breeding and showing, which they were unable to perform post-operatively. However, owners reported that subjectively, the animals’ quality of life was good and amputation provided a satisfactory outcome. Llamas and alpacas tend to do well with amputation because of their light body weight and generally calm disposition, which helps primarily in the immediate post-operative period. Amputation therefore may be a reasonable treatment option for companion camelids where financial constraints prohibit fracture repair.
Given that good clinical healing may still preclude return to function, owner satisfaction often does not match the clinical outcome. Results of this study support the hypothesis that internal fixation provides superior fracture alignment, stabilization, and long-term outcome in camelids with long-bone fractures. Internal fixation techniques should be recommended for animals if financial constraints are not an issue. Additionally, animals with open fractures were more likely to suffer from long-term complications as demonstrated by the significant over- representation of open fractures in the outcome score Group 4, and the over-representation of closed fractures in Group 1. Animals with closed fractures generally had more favorable outcomes and suffered fewer long-term complications. CVJ
Footnotes
Use of this article is limited to a single copy for personal study. Anyone interested in obtaining reprints should contact the CVMA office (hbroughton@cvma-acmv.org) for additional copies or permission to use this material elsewhere.
References
- 1.Kaneps AJ. Orthopedic conditions of small ruminants. Llama, sheep, goat, and deer. Vet Clin North Am Food Anim Pract. 1996;12:211–231. doi: 10.1016/s0749-0720(15)30444-8. [DOI] [PubMed] [Google Scholar]
- 2.Newman KD, Anderson DE. Fracture management in llamas and alpacas. Small Ruminant Research. 2006;61:241–258. doi: 10.1016/j.smallrumres.2005.07.012. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Rubio-Martinez LM, Koenig JB, Halling KB, Wilkins K, Schulz K. Use of a circular external fixator for stabilization of a comminuted diaphyseal metatarsal fracture in an alpaca. J Am Vet Med Assoc. 2007;230:1044–1048. doi: 10.2460/javma.230.7.1044. [DOI] [PubMed] [Google Scholar]
- 4.Staudte KL, Gibson NR. Type 1B external fixation of a metacarpal fracture in an alpaca. Aust Vet J. 2003;81:265–267. doi: 10.1111/j.1751-0813.2003.tb12567.x. [DOI] [PubMed] [Google Scholar]
- 5.Anderson DE, St-Jean G. External skeletal fixation in ruminants. Vet Clin North Am Food Anim Pract. 1996;12:117–152. doi: 10.1016/s0749-0720(15)30439-4. [DOI] [PubMed] [Google Scholar]
- 6.Tee SY, Dowling BA, Dart AJ. Treatment of long bone fractures in South American camelids: 5 cases. Aust Vet J. 2005;83:418–420. doi: 10.1111/j.1751-0813.2005.tb13080.x. [DOI] [PubMed] [Google Scholar]
- 7.Shoemaker RW, Wilson DG. Surgical repair of femoral fractures in new world camelids: Five cases (1996–2003) Aust Vet J. 2007;85:148–152. doi: 10.1111/j.1751-0813.2006.00099.x. [DOI] [PubMed] [Google Scholar]
- 8.Kaneps AJ, Schmotzer WB, Huber MJ, Riebold TW, Watrous BJ, Arnold JS. Fracture repair with transfixation pins and fiberglass cast in llamas and small ruminants. J Am Vet Med Assoc. 1989;195:1257–1261. [PubMed] [Google Scholar]
- 9.Newman KD, Anderson DE. Humerus fractures in llamas and alpacas: Seven cases (1998–2004) Vet Surg. 2007;36:68–73. doi: 10.1111/j.1532-950X.2007.00237.x. [DOI] [PubMed] [Google Scholar]
- 10.Johnson CR, Baird AN, Baird DK, Wenzel JG. Long-bone fractures in llamas: Six cases (1993–1998) J Am Vet Med Assoc. 2000;216:1291–1293. doi: 10.2460/javma.2000.216.1291. [DOI] [PubMed] [Google Scholar]
- 11.Semevolos SA, Huber MJ, Parker JE, Reed SK. Complications after orthopedic surgery in alpacas and llamas: 24 cases (200–2006) Vet Surg. 2008;37:22–26. doi: 10.1111/j.1532-950X.2007.00342.x. [DOI] [PubMed] [Google Scholar]
- 12.Brounts SH, Racette M, Muir P. Comparison of fixation methods for treatment of long bone fractures in llamas and alpacas. Vet Surg. 2010;40:115–119. doi: 10.1111/j.1532-950X.2010.00760.x. [DOI] [PubMed] [Google Scholar]
- 13.Fowler ME. Medicine and Surgery of South American Camelids: Llama, Alpaca, Vicuna, Guanaco. 2nd ed. Vol. 136 Ames, Iowa: Blackwell Publishing; 1998. pp. 50–55. [Google Scholar]