Treatment of Bilateral MeFissures in a Horse UsingMesenchymal Stromal Ce
Leah F. Raheja BS a, Larry D. GaluJoseph P. Dowd DVMd, Fern TabaDepartment of Anatomy, Physiology and Cell Biology, SbDepartment of Surgical and Radiological Sciences, SchcHarris Farms Horse Division, Coalinga, CAd Equine Medical and Surgical Group, Arcadia, CA
Joint pathology has been reported to be a major cause oflameness in horses and is estimated to account for 42%-60%[1,2] of lameness cases. The relatively avascular and hypoxic
nature of cartilage as a tissue, in addition to the non-proliferative characteristics of mature chondrocytes, oftenresults in a poor prognosis for complete recovery. In addi-tion, these cartilage injuries present with highly variableclinical signs and recovery outcomes. Factors that determinethe extent of healing include the depth, location, size, andweight-bearing environment of the lesion(s), in addition to
Journal of Equine Veterinary ScCorresponding author at: Larry D. Galuppo, DVM, Department ofcartilage defects 90 days after the initial arthroscopic examination. Follow-up treatmentsincluded two additional injections of MSCs suspended in lactated Ringers solution, 5 and13 months after the initial examination, directly into the joint. Post-treatment outcomewas assessed by arthroscopic examination and by comparison of preinjury and post-treatment performance records. Arthroscopic evaluation 4 months after the initialMSC treatment revealed marked smoothing, reduction in the depth of cartilage defectsand observation of moderate improvement in the cranial cruciate ligament. Approxi-mately 15 months after the initial MSC treatment the horse returned to racing. Analysisof race records demonstrated that the post-treatment (including all three MSC treat-ments) average race earnings (earnings per start) were comparable with those predatingthe initial injury. The favorable clinical response in the face of an unknown, but likely,guarded prognosis suggest that MSC therapy is not deleterious and may augment healingof articular cartilage ssures of the medial femoral condyle. MSCs represent a viable andpromising alternative therapy in the treatment of articular cartilage injuries in perfor-mance horses.
2011 Elsevier Inc. All rights reserved.Keywords:StieCartilageStem cellOCDRepairSurgical and Radiological Sciences, School of Veterinaryof California, Davis, 2112 Tupper Hall One Shields Ave, D
E-mail address: email@example.com (L.D. Galu
0737-0806/$ - see front matter 2011 Elsevier Inc. Adoi:10.1016/j.jevs.2010.12.009dial Femoral Condyle Articular CartilageBone Marrow-Derived Multipotentlls
ppo DVMb, Jeanne Bowers-Lepore DVMc,lin DVM, PhD a, Clare E. Yellowley PhD a
chool of Veterinary Medicine, University of California, Davis, CAool of Veterinary Medicine, University of California, Davis, CA
a b s t r a c t
The objective of this study was to describe the use, and outcome, of multipotentmesenchymal stromal cells (MSCs) in the treatment of equine articular cartilage defectsof the medial femoral condyle. A 4-year-old Thoroughbred gelding (n = 1) with bilateralstie athroscopy was found to have bilateral articular cartilage ssure defects of themedial femoral condyles with concurrent cranial cruciate ligament injury. Bone marrowderived MSCs were isolated, expanded, and suspended in a partially autologous bringlue. The initial cell/brin glue mixture was delivered arthroscopically into the articularCase StudyJournal of Equine
journal homepMedicine, Universityavis, CA 95616.ppo).
ll rights reserved.eterinary Science
ience 31 (2011) 147-154patient age and conformation [3,4]. Current treatments forinjuries related to articular cartilage in horses are ever
different between individuals receiving MSC-laden brin
2.1. Clinical Findings
A 4-year-old Thoroughbred gelding was presented forbilateral stie arthroscopy. The horse began racing inNovember 2004 as a 2-year-old and raced successfullythrough September 2006 with 11 starts (Table 1). Althoughthere was a clinical indication of subtle hindlimbperformance-limiting lameness in July 2006, physicalexamination, nuclear scintigraphy, and associated stieradiographic examination were inconclusive. However,there was slight attening noted on the medial femoralcondyles bilaterally (Fig. 1). In October 2006, the horse wasremoved from race training because of its inability toperform. There was no reported evidence of lameness at thetrot, however, the horse was unwilling to canter or gallop.On the basis of clinical assessment, a stie problem wassuspected. Screening for equine protozoal myeloencephalitis
e Veteevolving. A diagnosis is generally conrmed througharthroscopic examination and treatments include partialmeniscectomy, curettage or drilling into the subchondralbone, cartilage ap/fragment xation, and surgicaldebridement and microfracture [5-12]. In horses withlameness localized to the medial femorotibial joint havingsubtle radiographic changes of the medial femoral condyles,it was found that only two of six horses with generalizedcartilage lesions were reported as being sound and withoutany evidence of joint effusion after arthroscopic-guidedabrasion arthroplasty and microfracture . Prognosisdepends on the severity and location of the lesion(s),among other factors, and it is generally accepted thatthe percentage of patients making a complete recoverydecreases with increasing severity of injury . In anotherseries, 86% of horses with focal lesions of themedial femoralcondyle treated with arthroscopic curettage and debride-ment returned to normal function, whereas none of thehorses that presented with extensive and diffuse damage, inwhich arthroscopic treatmentwas not performed, recoveredcompletely . Both studies highlight a guarded prognosisfor horses with moderate to extensive damage to the carti-lage of the medial femoral condyle.
With limited options available for articular cartilagerepair and the efcacy of such options being variable,especially for extensive injuries, clinicians and researchersin both human and veterinary medicine have, over the pastdecade, looked into the potential of progenitor or stem cellsto aid in tissue regeneration and repair. Currently, only onecell-based therapy has been approved by the Food andDrug Administration for use in human beings (Carticel,Genzyme). This uses autologous chondrocytes harvestedfrom a non- or low load-bearing location that are thenexpanded in vitro, implanted into articular defects, andcovered by a periosteal ap. The efcacy of such therapy, asmeasured by a combination of function and pain , hasbeen reported to be >80% in human beings , withcomparable results in horses using a similar technique forthe repair of manufactured full-thickness defects in minorload-bearing areas of the tibiotarsal joint . However,induction of defects to harvest chondrocytes is a concernwith this type of cell therapy and comparable clinicalresults have been obtained with microfracture . Thus,other tissue sources for cellular therapy as well asimplantation methods are being considered.
Mesenchymal stromal cells (MSCs) are a multipotentadult stem cell population capable of differentiating intotissues of the mesenchymal lineages including bone,cartilage, and fat, and may also serve as trophic mediatorsaiding in attenuating the inammatory response [18-20].These cells have been referred to in the published data andby industry by a variety of names including mesenchymalstem cells and bone marrow stromal cells; we have chosento use the namemultipotentMSCs, as recommended by theInternational Society for Cellular Therapy . With therelative abundance and accessibility of MSCs for clinicalharvest, many clinicians and researchers have begun look-ing at the use of MSCs for cartilage , tendon [23,24],
L.F. Raheja et al. / Journal of Equin148ligament [23,24], and bone repair . Recently, there wasa report of the use of autologous MSCs in a brin glueenhancing the early repair of manufactured full-thicknessarticular cartilage/subchondral bone defect in the equineglue or control (MSC-free brin glue), the study did notcompare an untreated control, thus it is difcult to deter-mine whether the brin glue alone may have played a rolein healing. There is evidence in the published data thatbrin may serve as a scaffold for tissue repair, includingthat of cartilage, thereby contributing to the healingprocess [27,28]. The apparent benets of MSCs on earlyhealing should not be disregarded and may providea foundation for additional intra-articular cellular therapyto improve overall joint health. Although experimentalstudies are limited, there is less evidence for the efcacy ofsuch treatment in naturally occurring supercial lesions inwhich the subchondral bone is intact. In this case report,we describe the use of arthroscopically delivered autolo-gous MSCs in a partially autologous brin glue to treatbilateral diffuse ssure fractures of the medial femoralcondyles of a horse.
2. Materials and Methodsfemoropatellar joint . Although the report noted thatlong-term healing at 8 months was not signicantly
Table 1Preinjury performance records
Date of race Distance (furlongs) Placing Winnings ($)
November 25, 2004 6.5 1 13,200February 11, 2005 6 1 21,450March 5, 2005 6.5 1 66,270March 26, 2005 6.5 1 62,415April 22, 2005 5.5 5 2,002May 21, 2005 7 6 0February 19, 2006 6.5 0 0March 23, 2006 6 2 10,000May 20, 2006 7 3 8,580August 12, 2006 6.5 5 880September 16, 2006 6.5 7 400Average 6.41 3 16,836.09Total 70.50 32 185,197.00Starts 11.00
rinary Science 31 (2011) 147-154(indirect uorescent antibody test [IFA] for Sarcocystis neu-rona andNeospora hughesi) was negative. Bilateral diagnosticintra-articular anesthesia resulted in mark