pISSN 1598-298X / eISSN 2384-0749 J Vet Clin 36(4) : 196-199 (2019)
http://dx.doi.org/10.17555/jvc.2019.08.36.4.196
196
Fracture Analysis of Wild Birds in South Korea
Hyun-Kyu Jang, Jong-Moon Park, Sohail Ahmed, Seong-Hoon Seok*, Ho-Su Kim** and Seong-Chan Yeon1 Department of Veterinary Clinical Sciences and Research Institute for Veterinary Science, Seoul Wildlife Center,
College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Korea
*Daegu Animal Medical Center, 36, Dongdaegu-ro, Suseong-gu, Daegu 42185, Korea
**Busan Wildlife Treatment Center, 1240-2, Nakdongnam-ro, Saha-gu, Busan 49435, Korea (Received: April 05, 2019 / Accepted: August 10, 2019)
Abstract : This study was conducted to evaluate and analyze fractures types, sites and surgical approach of wild birds in Korea. The study was conducted on data collected for fracture lesion sites, species, outcomes, surgical methods, treatments and medical records from wildlife centers in South Korea. All birds were subjected to clinical examination, followed by surgical invasion and post-operative care. Fractures were more common in adult non-raptor species (51.57%) as compared to raptors (48.43%). Of the 254 cases evaluated, maximum cases comprised ulnar fractures (29.70%), followed by radial (21.76%) and humeral fractures (17.35%). Treatment procedures at 340 fracture sites were maximally treated with figure-8 bandage (33.07%), external skeletal fixator-intramedullary pin (ESF+IM tie-in fixation) (20.86%), and other varied procedures. All birds were kept indoors till recovery. Treatment outcomes were dependent on the type of bone fractured and surgical method applied. Based on the surgical treatments and outcomes, birds were kept hospitalized, and released or euthanized. The findings of this study provide information for veterinarians regarding the fractures sites, basic database for the species and outcomes of fracture repair in wild birds.
Key words : birds, raptors, fracture repair, figure-8 bandage, wildlife.
Introduction
A number of practical considerations need to be accounted for with wildlife than with domestic animals. Since wildlife have no owner to provide financial support for their needs, veterinarians who provide surgical care for wildlife have to also consider the post-operative care (9). Avian orthopedic techniques vary from mammalian procedures in several ways. Avian bones are thinner, more brittle, and pneuma- tized which are connected to air sacs (4). Because of these reasons, many fractured avian bones tend to be comminuted and open fractures (11). These fractures are found in multi- ple bones such as the humerus, femur, radius, and ulna;
often, these are complex fractures consisting of multiple bones of the joint (2).
Numerous wild migratory birds exist in South Korea. Every year, a dozen to hundreds of birds are accepted in wildlife centers presenting with bone fractures (6). Cage rest, cast and stent are frequently used for light injuries. In case of severe injuries, internal and external fixation are recommended (1,3).
As a wild bird has weaker bone strength compared to mam- mals, and numerous vessels exist in the bone lacuna, frac- tures may prove to be much more critical and mortal for birds (13). Since wild avians are more vulnerable to injury and an insanitary environment, even simple wounds can prove be life threatening. Fortunately, clinicians are trying to develop
and incorporate non-invasive surgical techniques for wild birds (5). To select an appropriate and adaptable technique, data was collected from 3 wildlife centers. We evaluated site and type of fractures, distribution of fracture sites according to the species, and outcomes of fracture managements.
Few studies have described and reported types of fractures in wildlife (14,15). The current study aimed to evaluate the types of fractures in raptors and non-raptors, to assess the prevalence of fracture by considering the bone involved, and to help veterinarians in identifying treatment methods avail- able with their outcomes.
Materials and Methods
We collected bird fracture data from Seoul, Gyeongnam, and Busan wildlife centers, for the period February 2016 to November 2018. Totally, 254 birds with 340 fracture sites that received surgical correction were evaluated in this study.
The collected data include species, number of cases, fracture lesion, treatment, and outcome of surgical invasion.
The investigation was based on patient records maintained at the wildlife centers. Data was categorized according to the bones involved, i.e., skull, hind limbs, forelimbs, fused verte- brae, and joints of birds. Details of data retrieved were arranged in order of skull, coracoid, scapula, clavicle, humerus, radius, ulna, femur, carpometacarpus, tarsometatarsus, tibiotarsus, digit, notarium and synsacrum. Considering the age, all frac- tures were categorized into 2 groups: juvenile and adults.
Surgical techniques or methods used to repair fracture and the prognosis of surgeries were evaluated considering their
1Corresponding author.
E-mail : [email protected]
Fracture Analysis of Wild Birds in South Korea 197
relevant outcomes, i.e., union, non-union, malunion, osteo- myelitis, appliance failure, and amputation of affected body part of the bird.
Different surgical treatments were implemented; these include figure-8 bandage, IM pinning, ESF + IM pin (tie-in fixation), splint, interdigital bandage, and ball bandage.
Depending on the type of surgical invasion, site of fracture, and outcome of treatments, the birds were categorized as hospitalized, euthanized, death during hospitalization and surgery, or reintroduced into wild habitat. All records were maintained according to the aim of the study.
Results
Species distribution
From data collected at the wildlife centers, 254 cases com- prising 60 different species underwent surgical repair of bone fractures. Considering the species, Common kestrel (Falco tinnunculus) were the maximum (Fig 1A), followed by Northern boobook (Ninox scutulata); distribution of the most abundant species is given in Table 1.
Location of fracture
According to the data, most fractures sites were related to the forelimbs (ulna 29.70%, radius 21.76%, humerus 17.35%;
Fig 1B), followed by tibiotarsus (8.82%), coracoid (7.05%), carpometacarpus (5%; Fig 3A, 3B), femur (3.52%), and other rare cases of fractures in digits, coracoid, scapula and tar- sometatarsus. Pictorial representation of a humeral fracture prior to surgery is shown in Fig 1B. A few cases having mul-
Fig 1. Common Kestrel (Falco tinnunculus). (A) Picture of wild Common Kestrel (Falco tinnunculus). (B) Common Kestrel (Falco tinnunculus) with fractured left humerus prior to surgical invasion at the wildlife center.
Table 1. Most abundant species with different bone fractures treated at wildlife centers
Common name Scientific name Number
of cases
Common kestrel Falco tinnunculus 40
Northern boobook Ninox japonica 22
Eurasian sparrow hawk Accipiter nisus 17 Brown-eared bulbul Hypsipetes amaurotis 14
Rock dove Columba livia 13
Cinereous vulture Aegypius monachus 10
Common buzzard Buteo buteo 09
Large-billed crow Corvus macrorhynchos 08
Eurasian eagle owl Bubo bubo 08
Grey heron Ardea cinerea 06
Great egret Ardea alba 06
Eurasian hobby Falco subbuteo 05
Table 2. Location of fracture
Location of fracture No. of patient affected Percentage
Skull 001 000.29%
Coracoid 024 007.05%
Scapula 005 001.47%
Clavicle 004 001.17%
Humerus 059 017.35%
Radius 074 021.76%
Ulna 101 029.70%
Carpometacarpus 017 005%
Femur 012 003.52%
Tibiotarsus 030 008.82%
Tarsometatarsus 005 001.47%
Digit 006 001.76%
Notarium 001 000.29%
Synsacrum 001 000.29%
Total 340 100%
tiple fractures were also investigated; these include the notar- ium, synsacrum and skull (0.29% each), as presented in Table 2. Ventrodorsal radiograph of comminuted left radial and ulnar fractures are shown in Fig 4A and 4B.
Age and taxonomy
Broadly, there are two categories with respect to age: juve- nile and adult birds. Fracture percentage was greater in adults (88.18%) as compared to juvenile birds (8.82%).
Taxonomy of birds is widely differentiated in 2 categories:
raptors and non-raptor species. The percentage of fracture in non-raptor species (51.57%) was higher than raptors (48.43%).
Surgical methods for treatment
Different surgical methods are employed to treat fractures in birds. These include ball bandage, cage rest, digit ban- dage, figure-8 bandage, IM pin, ESF + IM pin (Fig 2A, 2B), splint, and tape splint. Treatments for the 254 birds evalu- ated include cage rest, figure-8 bandage, IM pinning, ESF + IM pinning, splint, tape splint, interdigital bandage, and ball bandage. Of these, the figure-8 bandage was mostly fre-
198 Hyun-Kyu Jang, Jong-Moon Park, Sohail Ahmed, Seong-Hoon Seok, Ho-Su Kim and Seong-Chan Yeon
quently applied in 84 cases (33.07%). IM pinning and ESF + IM pin followed with 53 cases (20.86% each). Other treat- ment protocols were cage rest 46 (18.11%), tape splint 11 (4.33%), splint and interdigital bandage 3 cases (1.18% each), and 1 case of ball bandage (0.39%) (Table 3).
Fig 2. Humeral fracture in Common Kestrel (Falco tinnuncu- lus). (A) Post-operative picture of bird showing surgical repair of left humeral fracture with tie-in fixation using ESF + IM pin.
(B) Ventrodorsal radiograph showing surgical repair of the left humeral fracture with tie-in fixation using ESF + IM pin.
Fig 3. Carpometacarpal fracture in Common Kestrel (Falco tin- nunculus). (A) Ventrodorsal radiograph revealing comminuted left carpometacarpal fracture. (B) Ventrodorsal radiograph show- ing healed left carpometacarpus after coaptation (Splint and fig- ure-8 bandage). This bird achieved full flight and was released.
Fig 4. Radial and ulnar fractures. (A) Ventrodorsal radiograph of Northern Boobook (Ninox japonica), revealing comminuted left radial and ulnar fractures. (B) Ventrodorsal radiograph of Little Egret (Egretta garzetta), revealing comminuted left radial and ulnar fractures.
Table 3. Treatment of fracture
Treatment No. of cases Percentage
Cage rest 046 018.11%
Figure-8 bandage 084 033.07%
IM pinning 053 020.86%
IM pin + ESF (tie in) 053 020.86%
Splint 003 001.18%
Tape splint 011 004.33%
Interdigital bandage 003 001.18%
Ball bandage 001 000.39%
Total 254 100%
Table 4. Outcome during and after treatment
Outcome No. of cases Percentage
DOA 003 001.81%
Hospitalized 013 005.12%
Released 081 031.89%
Euthanized 029 011.41%
Dead 123 048.42%
Pending 005 001.96%
Total 254 100%
Fracture Analysis of Wild Birds in South Korea 199
Surgical outcomes
Of the 254 cases, there were 123 (48.42%) mortalities, 81 (31.89%) were released, 29 (11.41%) euthanized, 13 (5.12%) hospitalized, and 3 (1.81%) found dead on arrival (DOA).
The outcome of the 254 birds is presented in Table 4.
Discussion
According to a previous study, the most common species of raptors with fractures was the Common kestrel (Falco tin- nunculus), followed by the Northern boobook (Ninox scutu- lata) (9). However, rescued species in countries such as the USA, Greece, and Spain were mostly species other than the Common kestrel (Falco tinnunculus) and Northern boobook (Ninox scutulata) (10-12,15). The present study also revealed the unique pattern reported previously for fracture percent- age in Common kestrel (Falco tinnunculus) followed by Northern boobook (Ninox scutulata).
The humerus, radius, and ulna were the most frequent sites of fracture in the present study, which is similar to a previ- ous report (9). Furthermore, the percentage of fractures in the ulna (29.70%) was slightly lower than the previous report (approximately 50%) (9).
In the present study, we found 2 cases of fractures in the notarium and synsacrum region. The avian vertebral column exhibits fused, rigid vertebrae such as the notarium, synsa- crum, and pygostyle (2). This rigidity could be the cause of free thoracic vertebrae being vulnerable to fracture.
Moreover, in a previous study, patient reintroduction was reported to be the most frequent outcome of fracture manage- ment, followed by captivity; additionally, this study reported a very low death rate (10). Contrarily, the present study reveals a different percentage of outcome, with a higher death rate as compared to reintroduction of the wild birds into their habi- tat. In another study, the number of birds not released was higher than the released birds (7), which corresponds to the results of the current study.
Activity was minimized by separating the birds and pro- viding them cage rest. Birds were kept in cage rest for 14 to 21 days after surgery. In the present study, 18.11% birds were kept for cage rest, which correlates to a previous study report (3). Another study reported application of IM pins in 10 of the 13 surgically treated cases, excluding the 3 cases of ampu- tation. Of the 10 cases, ESF was performed in 2 cases and wire fixation in 1 case (9). In the present study, ESF + IM pinning was applied to 53 cases (20.86%), and there were 5 cases of amputation.
The percentage of treatment with ESF + IM pin was higher in a previous study (9) where ESF + IM pin were used in 54% cases, as compared to the present study, wherein ESF + IM pin and IM pin alone had equal proportions (20.86%).
Conclusion
The current study evaluated fractures in wild birds. The most common species with fractures was the Common kes- trel (Falco tinnunculus). Ulna was the most frequent site of fracture. The findings of this study will provide wildlife vet- erinarians information regarding the frequency and character-
istics of fractures in birds, and could also serve as a basic database for the treatment of fracture in wild birds. This study shows a similar pattern of fracture lesions and treat- ments as has been reported in earlier researches. However, there are differences in the survival rate and the prognosis.
Acknowledgement
This work was supported by the Research Resettlement Fund for the new faculty of Seoul National University.
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