Table Of ContentReference: Biol. Bull. 197: I 1-13. (August 1999)
Regeneration of Amputated Avian Bone by a Coral
Skeletal Implant
B. RINKEVICH1 S. BEN-YAKIR2 AND R. BEN-YAKIR2
, ,
' National Institute ofOceanography, Tel Shikmona, P.O.B. 8030, Haifa 31080, Israel: and
2 Hod-Hasharon Veterinan< Clinic, 17 Gordon Street, Hod Hasttaron, Israel
Bone fractures are common in both wild and captive avian bones (3-5) results in problems that are not encoun-
birds (I, 2). Avian bones are thin and brittle and tend to tered in mammals.
break intofragments or shatter upon a variety ofnatural We recently investigated the use of coral skeleton as a
events (midair collisions, fights with other animals; ref. 2) natural intramedullary fixation device for fractures of bird
or anthropogenic experiences (wounding by gunfire, colli- bone and found that fractured avian bones can be rehabili-
sions with cars orfences, encounters with traps, attacks by tated following the internal implantation of coral skeletal
dogs or cats, etc.; ref. 1). The prospect offull recovery pins (unpubl. data). This investigation was based on studies
following repair ofavion bonefracture is often poor, and with mammals (including humans) documenting that coral
the complication rate is high (3). For wild birds, anything skeletons may be employed as osseous substitutes, as scaf-
less than complete normal function cannot be regarded as folds for direct osteoblastic application, or as an artificial
successful, and slight malunion or a change in a few de- bone filler forrepairing bone defects (6, 7). The coral tested
greesofrotation canproducea severe lossofflightfunction here was ofthe branching species Stylophorapistillata, one
(4). Furthermore, in nomadic species, time is critical be- of the most abundant coral species in the Gulf of Eilat (8).
cause long periods ofrehabilitation may prevent the birds Mature domestic pigeons (Colmnba Hvia domestica)
from reunitingwith theirflocks. In experiments with implan- were randomly assigned to a variety oftreatment groups (in
tation offragments ofskeleton from the coral Stylophora preparation). For all radiographic and surgical procedures,
pistillata, wefound the implants to be avion osteo-conduc- the birds were given Halothane as a general anesthetic. The
tive biomaterial, acting as a scaffoldfora directosteoblas- skin was prepared for aseptic surgery using a septal scrub
tic deposition. In the case study presented here, the bird followed by a povidone-iodine wash. Whenever possible,
regained completeflight activity within 2 weeks after sur- flight feathers were not removed or clipped; others were
gery, withfull regeneration ofthe amputated ulna. pluckedoverthe intended incision. Reflexesandcardiac and
The general principles for treating fractures in birds are respiratory activities were monitored. Birds were placed on
similar to those established for mammals and include rigid their backs and a limited ventral approach to the ulna was
stabilization (primary bone healingdoes notoccurifthere is performed. Two of the same bones from the wings of two
a gap or motion at the fracture site; ref. 4). However, birds were used as experimental and control bones (ban-
treatment such as external coaptation (slings, bandages, daged in the traditional manner; ref. 5). Small processed
casts, splints, etc.), intramedullary pins or rods, bone plate coral pins were obtained from SagivCoral, P.O. Box 3337,
fixation, or modifications ofany ofthe traditional means of Ramot Hashavim 45930, Israel. Postoperative radiographs
external skeleton fixation (3-5) not only fails for rehabili- were taken to evaluate fracture repair and to document the
tating wild birds, but also involves prolonged hospitaliza- status of the coral implant. Pigeons were housed in the
tion of avian patients. Internal fixation is one of the best flypen system and fed with a commercial pigeon food
procedures forfracture management,butthebrittle natureof supplemented with vitamin D and oyster shell as a calcium
source.
Received 26 January 1999; accepted 23 April 1999. In one of the experiments, which is detailed in this
E-mail: [email protected] communication, the proximal half of the ulna (which pro-
11
B. RINKEVICH ET AL
Figure 1. Progressive repairofulna fracture treated hy implantation ofan intramedullary coral pin (a-e),
comparedtocontrol,anuntreatedamputatedulna(fl.Weeksafteroperation: a = 2. h = 4,c = 6,d = 8,e,f=
12.
vides primary support for the wing) was accidentally com- in layers and the first sign of coral resorption was evident.
minuted during surgery. Full rehabilitation of this amputa- During resorption. which was significantly advanced at 8
tion hone by the use of coral skeleton implant is described and 12 weeks (Fig. Id, e), radiography showed that the area
here. between the two ends of the broken ulna was being filled
In thecaseofthe accidentallycomminuted ulna, all brittle with accumulated new bone, replacing the degradable pin.
fragments were immediately removed and a small coral pin Sft'liiplwni pistillntti skeleton (although its mechanical and
mm mm
(24 length.4 diameter) was first passeddistally and biological properties were notyetevaluated) was thus found
then retrogradely until resistance was met at the proximal to be avian osteo-conductive biomaterial, acting as a scaf-
side of the ulna. The coral pin was then firmly wedged in fold fordirect osteoblastic deposition. The birdregained full
place, forming an inert calcium carbonate milieu between flight activities 2 weeks after surgery, and the coral pin
the two separated parts, replacing the amputated portion of activated skeletal regeneration (compare with the control;
the ulna. This pigeon used the treated wing freely 14 days Fig. If). This process ended in complete regeneration ofthe
after the operation, alleviating ankylosis resulting fromjoint amputated area.
immobilization. In the control bird, the entire segment of This case of regeneration of an amputated bone and our
proximal ulnar bone (cortex and medulla) was removed study (in prep.) demonstrate the value of coral skeletal
using Gilgi wire. implants for avian bone repair. Coral material (calcium
Two weeks after the operation, the coral pin was encap- carbonate) is well tolerated by bird tissue. The pin matrix is
sulated firmly at both ends by overgrown calcium deposits porous enough to be colonized by the birds' bony cells, is
and callus formation along the pin shall, providing rota- biodegradable, and is easily adjustable in size and shape to
tional stability (Fig. la). After 4 weeks (Fig. Ib). the coral the osseous site of grafting. Previous studies employing
implant was already overgrown by deposited material. By 6 coral implants for bone repair in mammals have shown that
weeks (Fig. Ic), deposited material surrounded the implant coral resorption rates varied with porosity of the coral
CORAL IMPLANTS IN AVIAN FRACTURES 13
species used and with host reaction (9). We used natural 2. Houston,D.C. 1993. Theincidenceofhealedfracturestowingbones
fragments of 5. pistillata skeletons, the first pocilloporid ofWhite-backedand Ruppell'sGriffonVulturesGypsafricaiiusandG.
coral used in vertebrate skeleton rehabilitation. Each year, 3. Mntatt'phpet'wtsln,aKn.dGo.t,heLr.biJr.dsW.alIlbiasce1,35P:.4T6.8-R4e7d5ig., J. E. Bechtold, R. R.
around the globe, veterinarians tend an ever-increasing Pool, and V. L. King. 1994. Avian fracture healing following stabi-
number of wild and domestic birds with broken bones; lization with mtramedullary polyglycolic acid rods and cyanoacrylate
unfortunately, at present the prognosis for many of these adhesive vs. polypropylene rods and polymethylmethacrylate. Vel.
birds is poor. The approach described here may provide a Comp. Orthop. Trauma 7: 15X-169.
fast and dependable method for rehabilitation ofavian frac- 4 Bennett, R. A., and A. B. Kuzma. 1992. Fracture management in
tures, increasing the survival rate of birds treated for bone 5. bMiardcsC.oJy.,ZoDo..MW.ild1l99M2e.il.T2r3e:at5m-e3n8t.of fractures in avian species. Vet.
injuries. dm. North Am. Small Aiiini. Pract. 22: 225-238.
6. Kehr, P. H., A. G. Graftiaux, F. Gosset, I. Bogorin, and K. Ben-
Acknowledgments cheikh. 1993. Coral as a graft in cervical spine surgery. Ortlmp.
Traumarol. 3: 287-293.
This study was supported by the Minerva Center for 7 Guillemin, G., J-L. Patat, and A. Meunier. 1995. Natural corals
Marine Invertebrate Immunology and Developmental Biol- used as bone graft substitutes. Bull. lust. Oceanogr. (Monaco) 14:
ogy. Animal surgeries and treatments were conducted in 67-77.
conformance with the guidelines of the Canadian Council 8. Loya, V. 1976. The Red Sea coral Stylophora pistillata is an r
on Animal Care. strategist. Nature (Land.) 259: 478-480.
9. Roudier, M., C. Bouchon.J. I.. Rouvillain,J. Amedee, R. Bareille,
F. Rouais, J. Ch. Fricain, B. Dupay, P. Kien, R. Jeandot, and B.
Literature Cited
Basse-Cathalinat. 1995. The resorption of bone-implanted corals
1. Fix, A. S., and S. Z. Barrows. 1990. Raptors rehabilitated in Iowa varies with porosity but also with the host reaction. J. Biomed. Mater.
during 1986 and 1987: aretrospective study.J. Wildl. Dis. 26: 18-21. Res. 29: 909-915.
