This study was

Animal Care and

University of Pe

One of the auth

was prepared as

article are those

policy or positio

J Shoulder Elbow Surg (2015) 24, 779-786

1058-2746/$ - s

http://dx.doi.org

www.elsevier.com/locate/ymse

A vascularized elbow allotransplantation modelin the rat

Juyu Tang, MDa, Hainan Zhu, MDb, Xusong Luo, MDb, Qinfeng Li, MDb,L. Scott Levin, MDc, LCDR Scott M. Tintle, MDd,*

aDepartment of Hand and Microsurgery, Xiangya Hospital of Central South University, Changsha, ChinabDepartment of Plastic and Reconstructive Surgery, Shanghai Ninth People’s Hospital, Shanghai JiaotongUniversity Medical College, Shanghai, ChinacDepartment of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA, USAdDepartment of Orthopaedic Surgery, Walter Reed National Military Medical Center, Bethesda, MD, USA

Background: The aim of this research was to develop a rat model for vascularized composite allotrans-plantation (VCA) of the elbow.Methods: We developed an animal model for VCA of the elbow in rats. Microvascular VCA was per-formed in 9 rats across a major histocompatibility barrier. Three different immunosuppressive regimenswere provided. Joint mobility and weight-bearing capability were assessed throughout 90 days of life.Pedicle patency, bone blood flow, and histologic analyses were performed.Results: In the cyclosporine group, forelimb activity was recovered during the postoperative 90 days. Theextremity that was operated on was used in daily activities. There was minimal motion or use of the limb inthe cyclosporine taper and control groups. The vascular pedicles were patent at the time of death in thecyclosporine-treated group but not in the remaining groups. Micro-computed tomography scan performed3 months after transplantation revealed union at the bone junctions, and the elbow joint appeared grosslynormal on death in the cyclosporine treatment group only. Incomplete healing was observed in the other 2groups, and the elbow joints were grossly destroyed. Histologic examination revealed normal cartilage andbone cells in the cyclosporine-treated group, whereas the nontreated groups demonstrated lymphocyticinfiltration and loss of normal histologic features. Flow cytometry of blood samples obtained on days14, 30, 60, and 90 showed no recipient cell chimerism in any of the groups.Conclusions: We developed an animal model for elbow VCA. Immunosuppressed animals regained nearlynormal function of forelimbs and maintained grossly normal elbow cartilage. Without cyclosporine treat-ment, the elbow transplants were rejected.Level of evidence: Basic Science, In Vivo Animal Study.Published by Elsevier Inc. on behalf of Journal of Shoulder and Elbow Surgery Board of Trustees.

Keywords: Vascularized; elbow; allotransplant; transplant; arthritis; rat

approved by the University of Pennsylvania Institutional

Use Committee: No. 804260. This study took place at the

nnsylvania, Philadelphia, PA, USA.

ors is an employee of the US Government and this work

part of his official duties. The views expressed in this

of the authors and do not necessarily reflect the official

n of the Department of the Navy, Department of the Army,

Department of Defense, nor the U.S. Government. Nothing in the pre-

sentation implies any Federal/DOD/DON endorsement. None of the au-

thors received financial support for this study.

*Reprint requests: LCDR Scott M. Tintle, MD, Walter Reed National

Military Medical Center, 8901 Wisconsin Avenue, Bethesda, MD 20889,

USA.

E-mail address: scott.tintle@gmail.com (LCDR S.M. Tintle).

ee front matter Published by Elsevier Inc. on behalf of Journal of Shoulder and Elbow Surgery Board of Trustees.

/10.1016/j.jse.2015.01.006

780 J. Tang et al.

End-stage elbow arthritis in the young patient is a vexing The following day, the skin of the rat was removed. The whole

problem. Potential surgical solutions include elbow jointd�ebridement, resurfacing arthroplasty, nonvascularizedelbow allografts, and total elbow replacement. None ofthese options, however, currently offers a realistic andlong-term solution to alleviate pain and to maintainmotion.1,3,6,7,9,10,15 Tissue-engineered joint replacementscurrently remain only a theoretical possibility.11 Whereasvascularized bone and joint autografts have proved suc-cessful for small joint reconstruction, expendable autograftsources are limited and do not provide viable donors forelbow reconstruction.2,8,22,24

The only viable solution is often surgical arthrodesis orresection arthroplasty, leaving a patient with a minimallyuseful extremity with minimal or no motion.10,16 The idealreplacement for a destroyed elbow joint would be a livingjoint allogeneic transplant that precisely matches the di-mensions and structural properties of the impaired joint.Despite the potential for this technology, few living vas-cularized transplantations of any large joint have beenperformed. There have been a few studies evaluating kneejoint allotransplantation in rats, and there have even beenvascularized allotransplantations in human knees, with onlyshort-term success and then failure.4,5,14 Given the currentimmunosuppressive regimens, elective joint allo-transplantation and the inherent side effects may not bewidely accepted. The scale, however, could realistically betipped in favor of performing elbow allotransplantation ifthe regimens could be improved by decreasing side effectsof the medications.12,14

An animal model is important to study this possibilityfurther. The rat has been frequently used in vascularizedcomposite allotransplantation (VCA) experimentationbecause of its easy handling, adequate size for microsurgery,and affordability. Multiple VCA models have previouslybeen established in the rat.13,14,21,25,26 We are, however,unaware of a rat elbow joint allotransplantation model.

Materials and methods

All animal care complied with the guidelines of the InstitutionalAnimal Care and Use Committee, the National Institutes ofHealth, and all national laws on the use of laboratory animals.

Experimental design, part I

In the first part of the experiment, inbred male brown Norway rats(genetic expression, RT1n) weighing 250 to 275 g were anes-thetized and eventually euthanized with carbon dioxide; they wereused to study the rat elbow and its vascular anatomy. Once it wasadequately anesthetized, the rat was perfused with heparinizedsaline, followed by 30 mL of red latex or Microfil (17.1 mLcontrast agent, 0.9 mL catalyst; Flow Tech, Inc., Carver, MA,USA). When the rat expired (termination of heartbeat and lungmovement), it was placed in 4�C overnight to allow the latex topolymerize.

arm was exposed, and the neurovascular structures were closelydissected and studied.

Experimental design, part II

In the second part of the experiment, 9 vascularized elbow jointsfrom brown Norway rats with residual biceps and triceps tendonsand the median nerve were transplanted across a strong majorhistocompatibility complex barrier to Lewis rats. The animalswere then randomly divided into 3 groups with different immu-nosuppressive regimens.

Animals and anesthesia

Brown Norway rats were also used as the donors in the secondpart of the experiment, and male Lewis rats (genetic expression,RT1l) weighing 250 to 275 g were used as the recipient animals.Both elbow joints of 1 donor rat were used for 2 transplantationprocedures (N ¼ 5). Donor rats were anesthetized with isofluraneinhalation at a dose of 3% for induction and 2% for maintenanceby inhalation. After graft harvest, they were euthanized with anoverdose of isoflurane (5%). Recipient rats were anesthetized withisoflurane as described for the donors. The rats were divided into 3different immunosuppressive regimens.

Group 1: cyclosporine treatment groupThree of the 9 recipients were given cyclosporine immunosup-pression at a dose of 16 mg/kg/day subcutaneously for the firstweek. The dose was then tapered down to a maintenance dose of2 mg/kg/day thereafter.

Group 2: temporary cyclosporine treatment groupThree recipients were given cyclosporine at the dose of 16 mg/kgfor 10 days, and then the immunosuppression was stopped.

Group 3: control groupThree recipients received no immunosuppression.

Harvest of vascularized elbow joint allotransplant(donor)

An anterior longitudinal incision was made over the entire armextending to the chest wall. The axillary vessels were dissected allthe way to the entrance of the thorax by elevating the pectoralismajor. After ligation, all major branches from the pedicle to theaxillary and brachial arteries were isolated and preserved. Themedian nerve was identified near the brachial artery. The ulnarnerve was identified at the midbrachial level and protected topreserve the ulnar collateral artery. The ulnar collateral arterytraversing with the ulnar nerve was identified, and a muscle cuffwas preserved to protect this vessel as it provides arterial supply tothe joint. The major anterior muscle groups of the arm wereidentified. The biceps was transected at a distal level, leaving onlya small tendinous portion. The flexors were identified and trans-ected at the midforearm level. At this time, the median, radial, andulnar arteries along with muscle perforators were identified,ligated, and cut. The ulnar recurrent vessel was identified, and amuscle cuff was saved to protect this vessel to the joint.

Figure 1 (A) Elbow allograft after brachial artery and median nerve anastomoses. (B) Elbow allograft after internal fixation of elbow andcoverage with recipient musculature.

Figure 2 Radiograph of rat after transplantation and fixationwith intramedullary needles.

Vascularized elbow allotransplantation model in the rat 781

The elbow joint of the rat was flexed, and another 2.5-cmincision posteriorly over the brachium extending distally over thesubcutaneous border of the ulna was made. The triceps wastransected, leaving a small tendinous portion inserting into theulna. The extensors were transected, and the posterior interosseousartery was identified between the ulna and the radius. The recur-rent interosseous artery, a branch from the posterior interosseousartery, was identified and preserved as it went into the joint. Thehumerus, radius, and ulna were then further exposed in a sub-periosteal fashion. The bones were then cut with a small powersaw. The elbow allograft was taken just proximal to the deltoidtuberosity and 2 mm distal to the origin of the recurrent inter-osseous artery. The pedicle of the graft was then transected asproximal as possible at the level of the axilla.

Preparation of recipient bed and transfer ofvascularized elbow joint

In the recipient Lewis rat, an anterior incision, from the distal thirdof the forelimb to the proximal third of the brachium, was madeover the elbow joint. The brachial artery and the median and ulnarnerves were identified. The ulnar nerve was isolated from thecubital tunnel and was transposed anteriorly. The radial nerve wasidentified, and special care was paid to isolate the radial nerve atthe radiocapitellar joint where the nerve lies close and is easilydamaged during the removal of the recipient elbow. Four musclegroups, biceps, triceps, flexors, and extensors, were identified andcut off at their insertions. Then, the humerus, radius, and ulnawere exposed and isolated from the soft tissue subperiosteally

from the middle arm to the middle forearm. The recipient elbowjoint was removed by cutting the brachial bone at the deltoid tu-berosity level and the radius and ulna 2 mm distal to the insertionof the biceps. The donor and recipient elbow joints were then heldside by side, and any adjustments to the length of the bones wasperformed to create a proper fit of the allograft (Fig. 1).

Intramedullary fixation and 90/90 wiring were used. Early in ourpreliminary study design, 90/90 wiring failed to produce reliableunion, and intramedullary fixation was selected for stabilization withimproved results (Fig. 2). A 20-gauge needle and two 27-gauge nee-dleswere used as intramedullary rods for the humerus and theulna andradius, respectively, after reaming with a slightly smaller needle. Allrecipient muscle groups (intact) were then attached to their corre-sponding donor parts with nonabsorbable 7-0 monofilament suture.Themediannervewascoapted to the recipientmediannerve in anend-to-side pattern to improve proprioception to the joint. A 2-cm incisionwas then made at the cervical region of the recipient rat. The externaljugular vein was exposed and prepared as the recipient vein. The in-ternal carotid artery was found just medial to the sternocleidomastoidmuscle and prepared as the recipient artery. The recipient artery (in-ternal carotid) and the recipient vein (external jugular) were ligatedand transected as distal as possible to leave long recipient vessels foranastomosis to the donor vessels. The donor pediclewas then tunneledto the neck region, and the end-to-end anastomosis was performedwith 11-0 nylon sutures under a surgical microscope. Finally, thewounds were closed with absorbable sutures.

In vivo assessment

The arms that were operated on were assessed daily for signs ofrejection, such as color changes, edema, and decreased motion.Other complications, such as bleeding, wound healing, and signsof infection, were also assessed daily for the first 10 days, thenevery other day.

Assessment of pedicle patency, graft blood flow,and joint architecture

After 90 days of survival, patency of the pedicle was evaluatedin a second nonsurvival anesthetic procedure. The transplant wasexposed under the operating microscope, and the pedicles werecarefully tested for patency by downstream occlusion andrelease. Blood flow was then measured by performing the pre-viously discussed contraction agent perfusion (Microfil),

Figure 3 Anatomic basis of vascularized elbow joint harvesting. The 4 arterial branches constitute the periarticular network(after latex perfusion). Also noted is the large nerve branch from the median nerve to the elbow joint.

782 J. Tang et al.

followed by gross inspection and micro-computed tomography(micro-CT) scanning. Micro-CT scanning was performed bothbefore and after the blood supply Microfil test using the in vivomicro-CT 40 (Scanco Medical AG, Br€uttisellen, Switzerland) at10-mm resolution. Three-dimensional angiograms were thenreconstructed. The bone morphologic changes were thencompared with a normal rat elbow joint.

Histologic assessment of viability andinflammation

The transplanted elbows were then sectioned for histologicassessment of the elbow joint and the cortical bone. Assessmentsof cartilage structure were made by looking for any signs ofchondrocyte and matrix degeneration.

Recipient chimerism evaluation

A chimerism analysis was performed on 1 � 104 cells usingFACScan (BD Biosciences, San Diego, CA, USA).

Results

Part I: vascular anatomy of the rat elbow

In the anatomic study, we found that 4 arterial branchesconstitute the periarticular network. These branches wereconsistently identified in the 3 rats studied. We identified(1) the recurrent interosseous artery, (2) the recurrent ulnarartery, (3) the ulnar collateral artery, and (4) the collateralradial artery (Fig. 3).

Part II: rat elbow allotransplantation

The mean surgical duration for the donor elbow harvest was2 hours, and the mean time for the recipient transplantationwas 4.5 hours. Warm ischemia time was 30 minutes. Threerats failed to recover from anesthesia and subsequentlydied. The remaining animals returned to their normal ac-tivities the second day after transplantation.

In vivo assessment

Group 1: cyclosporine treatment groupIn the cyclosporine-treated group, postoperative edema wasobserved in the first 5 days after the operation. No elbowjoint rigidity was noted throughout the experiment, and theshoulder joint regained normal activity and range of motionwithin 10 days after operation. The elbow joint motion aswell as the motion of the wrist and fingers continuouslyimproved in the 3 months after the operation. The rats usedthe forelimb that was operated on in daily life for holdingfood and scratching their faces. These animals also ambu-lated with normal quadrupedal ambulation. No signs ofrejection were observed (Fig. 4).

Group 2: short-term cyclosporine treatment group; andgroup 3: control group, no immunosuppressionIn the short-term cyclosporine-treated group and in thecontrol group receiving no immunosuppression, similarpostoperative edema was noted for about 5 days. Noobvious signs of rejection were demonstrated after theoperation; however, the grafted side showed less shoulderand elbow range of motion compared with the contralateralside and compared with the cyclosporine treatment group.Throughout the 3-month survival, these elbows becameprogressively stiffer until they were rigid by the time ofsacrifice.

Assessment of pedicle patency, graft blood flow,bone union, and joint architecture

The transplant was exposed under the operating micro-scope, and the pedicles were carefully tested for patency bydownstream occlusion and release. Blood flow was thenmeasured by performing the previously discussed contrac-tion agent perfusion (Microfil), followed by gross inspec-tion and micro-CT scanning.

Group 1: cyclosporine treatment groupThe pedicles remained grossly open on visual inspection aswell as with the patency test. Radiologic evaluations after

Figure 4 Note the active use of the transplanted left forelimb inthe cyclosporine (CsA) group (top), whereas the control rat is notweight bearing and holding the elbow flexed (bottom).

Figure 5 Note the preserved main pedicle (brachial artery).

Figure 6 Healed osteotomies with preserved joint structure.Note that the elbow is relatively extended.

Vascularized elbow allotransplantation model in the rat 783

Microfil perfusion demonstrated the patency of the pedicleand the circulation of the graft (Fig. 5). In the cyclosporine-treated group, plain radiographs and CT scans of the graftshowed good position and good fixation of the transplantedelbow 1 week after the operation (Fig. 6). Bone union wasdemonstrated at 90 days postoperatively. Histologicsamples revealed viable bone without signs of ischemicnecrosis or rejection in the cyclosporine-treated group atpost-transplantation day 90. Viable bone marrow was alsoobserved in the bone samples.

Groups 2 and 3: short-term cyclosporine group andcontrol groupThe pedicles were grossly constricted and did not have flowwith the patency test. Microfil perfusion showed vascularsprouting around the graft in a highly abnormal pattern withno evidence of the main pedicle (Fig. 7). No bone healingwas seen 3 months after the operation, and micro-CTshowed obvious degeneration, absorption, and fractures ofthe joint (Fig. 8). Histologic sections revealed little or noviable bone marrow and minimal viable cartilage at theelbow joint. There was a large amount of lymphocyteinfiltration visible in both of these groups (Fig. 9).

Recipient-donor chimerism evaluation

No obvious chimerism was evidenced on day 10, day 30,and day 60 after transplantation.

Discussion

Previous studies in a rat population have shown thatsurgical neoangiogenesis has allowed short-term boneallotransplants to survive without immunosuppression.14

Whereas a great deal of research is currently underway in promoting tolerance of VCA, the allotransplant ofan elbow joint may differ significantly. As in our model,the skin is not necessary to transplant the joint, andthus the antigenicity of the transplant may differ signif-icantly from a transplant that contains highly antigenicskin.

During the past decades, osteoarticular elbow allograftreplacement has become a potential option for elbow recon-struction in the severely damaged elbow.2,3,6-11,14-16,22,24

The initial postsurgical results were often satisfactory, yetmost cases inevitably resulted in severe and obvious degen-erative joint changes in the midterm follow-up.10 With therapid advances of VCA, vascularized joint allograft

Figure 8 Note the dislocated, severely destroyed elbow joint inthis elbow without immunosuppression.

Figure 7 The main pedicle (brachial artery) is difficult to see,and note the abundant neovasculature present.

784 J. Tang et al.

transplantation might become the solution for end-stageelbow arthritis if immunosuppression can be minimized.14

Diefenbeck et al4 have published their results of knee allo-transplantation, which have unfortunately all been lostbecause of graft vasculopathy.

In a beautifully performed study, Wavreille et al23

published their anatomic research for a potential vascu-larized elbow joint transplant in humans in 2006.Although this would be the ultimate goal (vascularizedelbow allotransplantation), more basic science research isclearly needed before this endeavor. An animal model isneeded to further progress this potential surgical treat-ment. Our research aimed to develop a vascularized elbowallograft model in the rat across a major histocompati-bility barrier.

Part I: vascularity of the rat elbow

We determined, as previously noted, that 4 main branchesvascularize the elbow joint. In addition, we noted that therewas a large branch from the median nerve to the elbowjoint. We thought that this was likely a major propriocep-tive component to the elbow joint and thus performed anend-to-side coaptation to the recipient’s median nerve. Itwas our intent that this coaptation will help the proprio-ceptive function of the joint and prevent neuropathicdegeneration.

Part II: rat elbow allotransplantation

This study demonstrates that a vascularized elbow allografttransplantation can be performed in the rat across a majorhistocompatibility complex barrier. We have additionallyconfirmed that short-term immunosuppression and noimmunosuppression lead to rejection of the allograft

transplant. The in vivo assessments demonstrated a largedifference between group 1 and groups 2 and 3. We werenot able to distinguish groups 2 and 3 either clinically or inthe laboratory, and therefore the results of both have beenpresented together. The clinical differences between thecyclosporine group 1 and the other 2 groups were obvious.The immunosuppressed rats’ forelimb use increased overtime, whereas the other 2 groups’ limbs became stiff andwere used minimally.

The patency of the pedicle was verified surgically aswell as with angiography using Microfil and then by micro-CT scanning of the elbow joints. The main pedicle of thebrachial artery was seen in group 1, whereas in the othergroups, the main pedicle was no longer visualized patentcrossing the joint. In the other groups, we found an abun-dance of neovascular tissue surrounding the joint, whichappeared to be an attempt to revascularize the elbow jointunsuccessfully. The use of the micro-CT scanner allowedus to verify that there was indeed union at our osseousjunctions in the group 1 rats treated with cyclosporine,whereas nonunions were obvious in the other 2 groups. Inaddition, the joint destruction was seen when micro-CTimages of the nonimmunosuppressed elbows were per-formed. The histologic slides of the joint graphicallydemonstrate the preservation of the joint structure in theimmunosuppressed group and progressive destruction inthe other 2 groups.

Chimerism has been demonstrated after bone marrowtransplantation in rat models17,19,20; however, no chimerismhas been reported in humans to date.14,18 We did not detectany donor-specific chimerism in our animal model, and thisresult was not unexpected.

We did note some problems in our experimentationworthy of note. Early on, we used 90/90 wiring and notedthat the rats had a difficult time healing the transplant bonejunctions, so we switched to intramedullary fixation with

Figure 9 The upper left image is a control elbow that did not have surgery. The upper right is a transplanted elbow that receivedcyclosporine; note the relatively preserved joint architecture. The lower left is a destroyed elbow joint in the short-term cyclosporine group.The lower right is the control group that was transplanted without immunosuppression.

Vascularized elbow allotransplantation model in the rat 785

needles. During the postoperative 90 days, there were nosevere complications necessitating graft removal. Therewere superficial wound infections in 2 animals that healedafter d�ebridement.

Conclusion

Despite the low number of transplants performed, thisstudy confirms the surgical feasibility and survival ofa vascularized elbow allograft transplant in a ratmodel when it is properly immunosuppressed. Short-term follow-up demonstrated no obvious degenerativejoint changes, and the animals appeared to be usingtheir limbs normally. Despite the feasibility of thisprocedure, more transplants need to be performed,and a more quantitative approach to results mea-surements would improve the validity of this study inthe future.

Disclaimer

The authors, their immediate families, and any researchfoundation with which they are affiliated have notreceived any financial payments or other benefits fromany commercial entity related to the subject of thisarticle.

References

1. Athwal GS. Revision total elbow arthroplasty for prosthetic fractures.

J Bone Joint Surg Am 2006;88:2017. http://dx.doi.org/10.2106/JBJS.

E.00878

2. Chen SH, Wei FC, Chen HC, Hentz VR, Chuang DC, Yeh MC.

Vascularized toe joint transfer to the hand. Plast Reconstr Surg 1996;

98:1275-84.

3. Delloye C, Cornu O, Dubuc JE, Vincent A, Barbier O. Recon-

struction du coude par allogreffe massive ost�eo-articulaire totale:�echec pr�ecoce par instabilit�e. Rev Chir Orthop Reparatrice Appar

Mot 2004;90:360-4.

4. Diefenbeck M, Nerlich A, Schneeberger S, Wagner F, Hofmann GO.

Allograft vasculopathy after allogeneic vascularized knee trans-

plantation. Transpl Int 2010;24:e1-5. http://dx.doi.org/10.1111/j.1432-

2277.2010.01178.x

5. Diefenbeck M, Wagner F, Kirschner MH, Nerlich A, M€uckley T,

Hofmann GO. Outcome of allogeneic vascularized knee transplants.

Transpl Int 2007;20:410-8. http://dx.doi.org/10.1111/j.1432-2277.

2007.00453.x

6. Ehsan A, Lee B, Itamura JM. Total elbow allografts with collateral

ligament reconstruction for posttraumatic elbow injuries. J Orthop Sci

2010;15:795-803. http://dx.doi.org/10.1007/s00776-010-1540-7

7. Funovics PT, Schuh R, Adams SB, Sabeti-Aschraf M, Dominkus M,

Kotz RI. Modular prosthetic reconstruction of major bone defects of

the distal end of the humerus. J Bone Joint Surg Am 2011;93:1064-74.

http://dx.doi.org/10.2106/JBJS.J.00239

8. Hierner R, Berger AK. Long-term results after vascularised joint

transfer for finger joint reconstruction. J Plast Reconstr Aesthet Surg

2008;61:1338-46. http://dx.doi.org/10.1016/j.bjps.2007.09.035

9. JaffeKA,Morris SG, Sorrell RG,GebhardtMC,MankinHJ.Massive bone

allografts for traumatic skeletal defects. Southampt Med J 1991;84:975.

10. Kharrazi FD, Busfield BT, Khorshad DS, Hornicek FJ, Mankin HJ.

Osteoarticular and total elbow allograft reconstruction with severe

786 J. Tang et al.

bone loss. Clin Orthop Relat Res 2008;466:205-9. http://dx.doi.org/10.

1007/s11999-007-0011-8

11. Kosuge D, Khan WS, Haddad B, Marsh D. Biomaterials and scaffolds

in bone and musculoskeletal engineering. Curr Stem Cell Res Ther

2013;8:185-91. http://dx.doi.org/10.2174/1574888X11308030002

12. Kremer T, Giusti G, Friedrich PF, Willems W, Bishop AT,

Giessler GA. Knee joint transplantation combined with surgical

angiogenesis in rabbitsda new experimental model. Microsurgery

2012;32:118-27. http://dx.doi.org/10.1002/micr.20946

13. Kulahci Y, Siemionow M. A new composite hemiface/mandible/

tongue transplantation model in rats. Ann Plast Surg 2010;64:114-21.

http://dx.doi.org/10.1097/SAP.0b013e3181a20cca

14. Larsen M, Friedrich PF, Bishop AT. A modified vascularized whole

knee joint allotransplantation model in the rat. Microsurgery 2010;30:

557-64. http://dx.doi.org/10.1002/micr.20800

15. Larson AN, Adams RA, Morrey BF. Revision interposition arthro-

plasty of the elbow. J Bone Joint Surg Br 2010;92:1273-7. http://dx.

doi.org/10.1302/0301-620X.92B9.24039

16. Moghaddam-Alvandi A, Dremel E, G€uven F, Heppert V, Wagner C,

Studier-Fischer S, et al. Arthrodesis of the elbow joint. Unfallchirurgie

2010;113:300-7. http://dx.doi.org/10.1007/s00113-009-1722-y

17. Muramatsu K, Doi K, Kawai S. Limb allotransplantation in rats:

combined immunosuppression by FK-506 and 15-deoxyspergualin. J

Hand Surg Am 1999;24:586-93. http://dx.doi.org/10.1053/jhsu.1999.

0586

18. Petruzzo P, Dubernard JM. The International Registry on Hand and

Composite Tissue allotransplantation. Clin Transplant 2011:247-53.

19. Plissonnier D, Nochy D, Poncet P, Mandet C, Hinglais N, Bariety J,

et al. Sequential immunological targeting of chronic experimental

arterial allograft. Transplantation 1995;60:414.

20. Siemionow M, Klimczak A, Unal S, Agaoglu G, Carnevale K. He-

matopoietic stem cell engraftment and seeding permits multi-

lymphoid chimerism in vascularized bone marrow transplants. Am J

Transplant 2008;8:1163-76. http://dx.doi.org/10.1111/j.1600-6143.

2008.02241.x

21. Siemionow M, Klimczak A. Advances in the development of experi-

mental composite tissue transplantation models. Transpl Int 2010;23:

2-13. http://dx.doi.org/10.1111/j.1432-2277.2009.00948.x

22. Silberman J, Kanat IO. Total joint replacement in digits of the foot. J

Foot Surg 1984;23:207-12.

23. Wavreille G, Remedios Dos C, Chantelot C, Limousin M, Fontaine C.

Anatomic bases of vascularized elbow joint harvesting to achieve

vascularized allograft. Surg Radiol Anat 2006;28:498-510. http://dx.

doi.org/10.1007/s00276-006-0130-z

24. Wetke E, Zerahn B, Kofoed H. Prospective analysis of a first MTP

total joint replacement. Evaluation by bone mineral densitometry,

pedobarography, and visual analogue score for pain. Foot Ankle Surg

2012;18:136-40. http://dx.doi.org/10.1016/j.fas.2011.07.002

25. Yazici I, Carnevale K, Klimczak A, Siemionow M. A new rat model of

maxilla allotransplantation. Ann Plast Surg 2007;58:338-44. http://dx.

doi.org/10.1097/01.sap.0000237683.72676.12

26. Yazici I, Unal S, Siemionow M. Composite hemiface/calvaria trans-

plantation model in rats. Plast Reconstr Surg 2006;118:1321-7. http://

dx.doi.org/10.1097/01.prs.0000239452.31605.b3