LITHUANIAN UNIVERSITY OF HEALTH SCIENCES VETERINARY ACADEMY

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LITHUANIAN UNIVERSITY OF HEALTH SCIENCES

VETERINARY ACADEMY

Faculty of Veterinary Medicine

Anna Hofmann

The Development and Use of Canine Platelet Rich Plasma Therapy to

Treat Osteoarthritis

Trombocitais praturtintos plazmos (angl. PRP) panaudijimas šunų

osteoartritui gydyti

MASTER THESIS

of Integrated Studies of Veterinary Medicine

Supervisor: Veterinary doctor Martinas Jankauskas

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2 THE WORK WAS DONE IN THE DEPARTMENT OF Small animal clinic CONFIRMATION OF THE INDEPENDENCE OF DONE WORK

I confirm that the presented Master Thesis

„The Development and Use of Canine Platelet Rich Plasma Therapy to Treat Osteoarthritis” 1. has been done by me;

2. has not been used in any other Lithuanian or foreign university;

3. I have not used any other sources not indicated in the work and I present the complete list of the used literature.

2021-05-13 Anna Hofmann

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CONFIRMATION ABOUT RESPONSIBILITY FOR CORRECTNESS OF THE ENGLISH LANGUAGE IN THE DONE WORK

I confirm the correctness of the English language in the done work.

2021-05-13 Owen Michael Levins.

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CONCLUSION OF THE SUPERVISOR REGARDING DEFENCE OF THE MASTER THESIS

Veterinary doctor Martinas Jankausas

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THE MASTER THESIS HAVE BEEN APPROVED IN THE

DEPARTMENT/CLINIC/INSTITUTE

(date of approval) (name, surname of the head of department/clinic/institute)

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Reviewer of the Master Thesis

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Evaluation of defence commission of the Master Thesis: (date) (name, surname of the secretary of the

defencecommission)

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3

SUMMARY

The Development and Use of Canine Platelet Rich Plasma Therapy to Treat Osteoarthritis Anna Hofmann

This study was carried out with the objective of determining if Platelet Rich Plasma Therapy as a treatment for Osteoarthritis in dogs demonstrates a significant improvement.

The canine patients were examination thoroughly and the degree of Osteoarthritis with the OA staging tool was determined. With regards to the owners’ wishes, the study participants were divided into three different groups: Group one received the PRP therapy, group two received therapy with NSAIDs and group three did not receive any treatment. All three groups consisted of ten dogs of different breeds and weights. Using the Osteoarthritis staging tool, every dog of every group was evaluated and graded again before and after six month the treatments. The statistical analysis showed a significant (p= 0,002) improvement of clinical signs of Osteoarthritis in dogs in group one, which received platelet rich plasma therapy. The statistical analysis revealed that on average the subjects osteoarthritis stage reduced by 1,25 using the OA staging tool. Group two of patients, who received the standard therapy of NSAIDs, showed no statistically significant reduction (p=0,025). 70% of the patients remained at the same level on the OA staging scale. The remaining 30% showed possible signs of improvements.

The 3rd_{group, who did not receive any treatment, did not show a significant (p=0,025)}

improvement of the clinical signs of Osteoarthritis.

After determination if PRP therapy does have a positive effect in general, factors such as location of OA, weight and age were studied. This showed significant differences in the effect of PRP therapy. Patients with OA located in the Stifle joint had a significant improvement after treatment with a p-value of p=0,031, while patients with OA in the Elbow joint had no significant improvement with p=0,063.

The same was seen with age, geriatric patients had no improvement with p=0,25, while adult dogs did show significant improvement with p=0,008.

While studying the effect of weight with regards to the effectiveness of PRP therapy, it showed that obese dogs did not show an improvement with p=0,125 but normal weight dogs did show a significant improvement with p=0,031.

The factors of location of OA, weight and age did not show any significant influence on the patients, who received NSAID treatment nor on patients without any treatment.

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7

SANTRAUKA

Trombocitais praturtintos plazmos (angl. PRP) panaudijimas šunų osteoartritui gydyti. Anna Hofmann

Šis tyrimas buvo atliktas siekiant nustatyti ar trombocitais praturtintos plazmos (angl. PRP) gydymo metodas turi reikšmingos naudos gydant šunų osteoartritą.

Tyrimui buvo atrinkti šunys, sergantys osteoartritu. Ištyrus pacientus, jiems buvo nustatytas osteoartrito laipsnis, remiantis AO standartizuota osteoartrito laipsnių sistema. Šeimininkai rinkosi galimą gydymo būdą, kai kurie gydymo atsistakė, pagal tai buvo sudarytos trys tiriamųjų grupės: pirmoji grupė, kuriems buvo taikytas PRP gydymas, antroji grupė kuriems buvo skirti nesteroidiniai vaistai nuo uždegimo (NVNU), trečioji grupė - neskirtas joks gydymas.

Visas tris grupes sudarė dešimt skirtingų veislių ir svorio šunų. Naudojant AO standartizuota osteoartrito laipsnių sistemą, kiekvienos grupės šuo buvo įvertintas prieš ir po šešių mėnesių. Statistinė analizė parodė reikšmingą (p = 0,002) klinikinių osteoartrito požymių pagerėjimą pirmos grupės šunims, kuriems buvo taikytas gydymas trombocitais praturtinta plazma.

Statistinė analizė parodė, kad vidutiniškai tiriamųjų osteoartrito laipsnis sumažėjo 1,25, naudojant OA vertinimo įrankį. Antroje pacientų grupėje, kuriai buvo taikomas standartinis NVNU gydymas, statistiškai reikšmingo sumažėjimo nėra (p = 0,025). 70% pacientų OA vertinimo skalėje išliko tame pačiame lygyje. Likę 30% parodė galimų simptomų gerėjimo ženklų.

Trečioje grupėje, kur nebuvo taikytas joks gydymas, nebuvo ir gerėjimo vertinant osteoartrito laipsnį (p=0,025).

Nustačius, ar PRP terapija turi teigiamą poveikį, buvo tiriami tokie veiksniai kaip osteoartrito vieta, svoris ir amžius. Tai parodė reikšmingus PRP terapijos poveikio skirtumus. Pacientams, kurių osteoartritas yra kelio sąnaryje, po gydymo buvo stebimas reik6mingas pagerėjimas (p= 0,031), o pacientams, kurių osteoartritas buvo alkūnės sąnaryje - reikšmingo pagerėjimo nebuvo (p = 0,063). Taip pat stebimi skirtumai lyginant amžiaus grupes, vidutinio amžiaus gyvūnams buvo stebimas statistiškai reikšmingas rezultatas gydant osteoartritą (p=0,008), o geriatriniams pacientams rezultatas nėra statistiškai reikšmingas (p=0,25).

Tiriant svorio priklausomybę rezultatams, buvo stebima jog nutukusiems gyvūnams gydymo rezultatas nebuvo statistiškai patikimas (p=0,125), kur normalaus svorios šunims buvo stebimas statistiškai patikimas rezultatas (p=0,031)

Antros ir trečios grupės pacientams nebuvo stebima nei vietos, nei svorio ir amžiaus įtaka osteoartrito laipsnio pasireiškimui.

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ABBREVIATIONS

OA – Osteoarthritis e.g. – exempli gratia M. – Musculus V. – Vena

PRP – Platelet Rich Plasma

NSAID – Nonsteroidal anti-inflammatory drug CT – Computer tomography

MRI – Magnetic resonance imaging X-ray – X-radiation

COX – cyclo-oxygenase Ligg. - ligament

DMOAD- Disease modifying osteoarthritic drugs IL- Interleukin

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9

INTRODUCTION

Over the years, Osteoarthritis has become a more and more common problem for dogs. Due to various reasons, dogs can develop Osteoarthritis in different age stages and independent from genetic prepositions. (1)

This can happen due to injuries, local infection or age-related degeneration of the articular joint tissue.

The general wellbeing and behavior of the dog are compromised by the condition and it can be very painful for the animal as well as restrict their movements. The more time that passes without accurate treatment, the worse it gets for the dog. This is, unfortunately, not a disease that can heal over time without treatment. (1-3)

Due to this, dogs often do not want to get daily exercise and cannot meet their exercise goals to keep them physically and mentally healthy.

For dog owners, this can affect the daily life significantly and they want their dog to be happier and as healthy as possible again. (1)

Therefore, as a veterinarian, it is important to investigate different new approaches to osteoarthritis therapies and communicate the results seen and risks involved honestly with the patient owners.(1)

In human medicine, the treatment of osteoarthritis with platelet-rich plasma has shown great results for the patients. Due to the plasma’s analgesic, anti-inflammatory, anti-fungal, tissue nutritional and promotion of articular tissue healing properties, it holds great promise for the treatment of osteoarthritis. (1, 32)

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AIMS AND OBJECTIVES OF THE THESIS

This study was carried out with the objective to investigate and compare Platelet Rich Plasma therapy as a treatment option of Osteoarthritis in Canines.

The aim is to either prove or disprove the positive effects of PRP therapy for dogs suffering from Osteoarthritis and if factors of age, weight or location in the joint has an influence on the treatment.

To do so, the following tasks of the work were carried out:

1. To compare the three different treatment options using 30 canine patients

2. To study the correlation between treatment effectiveness and location in the joint of Osteoarthritis 3. To study the correlation between treatment effectiveness and weight

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1. LITERATURE REVIEW

1.1. Canine Osteoarthritis

1.1.1. Definition

To determine the definition of Osteoarthritis, it is necessary to understand what normal cartilage is made of.

When we speak of “normal cartilage” we mean a complex material which consists of a solid matrix, primarily of collagen and proteoglycan which is saturated in water.

This heterogenous material is managed by chondrocytes, which are responsible for maintaining and synthesizing this material.

Furthermore, the interaction of biochemical and physical structures is necessary to allow the normal function of motion, frictionless, wear resistant, joint congruence and transmission of load to subchondral bone. (1)

When the normal cartilage structure and homeostasis is disrupted, Osteoarthritis occurs. It is the result of complex interaction of biochemical and biomechanical factors that occur concurrently and serve to continue degradative change. (1, 2)

Therefore, it can be characterized by hyaline cartilage thinning, joint effusion, and osteophyte formation. This progressive degeneration of the joint can be caused by infection, trauma, development malformations or immune-mediated diseases. (3,4)

Whichever the cause for the joint degeneration, it results in chondrocyte necrosis, release of degradative enzymes, synovitis and continuing cartilage destruction and inflammation. (4)

These changes resulting from Osteoarthritis have ultimately an impact on the patient through decreased ability to use the joint or production of pain, or both. (1, 2)

It is important to know however, that pain and lameness develops secondary to joint dysfunction or muscle atrophy and to disuse of the limb. (3,4)

1.1.2. Pathogenesis of Osteoarthritis

Primary form of osteoarthritis is in general affecting more than one joint and is known as oligoarticular.

A secondary form of osteoarthritis is in case of an underlying systemic disease or local injury. This causes the cartilage to destruct and results in secondary osteoarthritis.

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12 either by changes of the subchondral bone suggesting a primary alteration of the subchondral region or a disruption in the metabolic activity of chondrocytes in healthy cartilage. (2)

1.1.3. Morphological changes of Osteoarthritis

When examining the morphological changes of Osteoarthritis, cartilage erosions as well as a variable degree of synovial inflammation is seen. These are likely due to a complex network of biochemical factors, including proteolytic enzymes which lead to a breakdown of the macromolecules of cartilage. (3)

IL-1 and TNF- alpha cytokines produced by activated synoviocytes, mononuclear cells or articular cartilage itself, up-regulates metalloproteinases gene expression. Those cytokines also blunt the chondrocyte compensatory synthesis pathways, which are required to restore the degraded extracellular matrix. When looking closer at the synovium of Osteoarthritis, a deficit in the production of IL-1 receptor antagonists was demonstrated and could be the reason for excess production of nitric oxide in Osteoarthritis tissue. Coupled with the upregulation in the receptor level, this has been shown to an enhancer of the catabolic effect of IL-1 in this disease. (3,4)

1.1.4. Differences in regions

Before looking closely at two of, for this study, most important regions of OA, it is important to know how a joint is composed in general.

1.1.4.1. Joint composition

An articulatio synovialis, or also called “real joint”, contrary to Articulatio cartilaginous, have joint spaces between two bones. A joint is composed of:(5,6,10)

joint ends, epiphysis; joint cartilage, cartilage articularis; joint capsules, capsula articulare; joint cavities, cavum articulare; joint fluids, synovia (6); joint ligaments, ligamenta (6, 10) and intraarticular structures such as menisucus articularis, discus articularis, labrum articularis and ligg. Intracapsularia.The cartilage, composed of hyaline cartilage, covers the fascies articulares of the skeletal components and differs in size due to the mechanical load that is on the joint. In comparison to other hyaline cartilage, the joint cartilage is missing the perichondrium which reduces its ability to regenerate.(6, 9). The joint capsule is made of two layers: stratum fibrosum and stratum synoviale.

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13 Joint components can also be divided into passive and active components. Passive components are static and unable to contract whereas active components are dynamic and can actively contract. (5,12)

1.1.4.2. Elbow region

The cubital joint is a hinge joint, which means the main motion is limited to the sagittal plane. This joint is formed by humerus, radius and ulna and is divided into three joints: (5)

Humeroradial joint: composed of humerus and radius, it is responsible of around 52% of weight-bearing forces.

Proximal radioulnar joint: radius and ulnar bone and bears around 48% of forces. It also allows supination and pronation.

Humeroulnar joint: Humerus and ulnar bone which is restricting the motion of the elbow to sagittal plane motion: flexion and extension. (5, 11)

1.1.4.3. Stifle region

The joint of the stifle region is a large complex condylar joint. Joints in this region are: Femorotibial joint – articulating between femoral and tibial condyles

Femoropatellar joint

Tibial and femoral condyles joint surfaces are convex and the plateau of the tibia is tilted, making the stifle an unstable joint without the soft tissue supporting structures.

This is one of the main reasons why injuries to this joint are very painful and often result in instability and dysfunction. (5, 12, 13)

1.2. Diagnostic procedures for Osteoarthritis

Before going into detail of the treatment of OA, it is important to look closer at how it can be diagnosed.

Often Osteoarthritis is undiagnosed, which causes dogs pain and worsening of the condition. (15) 1.2.1. Clinical examination

Clinical examination is the most important part of every disease diagnosis. During clinical examination of Osteoarthritis, the following signs can be seen in dogs:

• Pressure or manipulation of effected area results in a pain response • The joint capsule is thickened due to osteophyte production

• Range of movement is decreased

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14 1.2.2. Diagnostic Imaging

In most patients, the degenerative joint changes are secondary to another cause. Diagnostic imaging is used to define the nature and extent of the joint degeneration and to identify the underlying primary cause. (15-17)

Although most clinics use X-Ray as the primary diagnostic imaging tool, more and more

veterinarians are using CT scans or MRI scans to help get a better picture of the cause and extent of disease. (15, 16)

1.2.3. Osteoarthritis Staging tool

After the clinical examination, the patient was assessed and graded both by the owner and the veterinarian. The veterinarian also graded the joints and after careful examination staged the severity of the Osteoarthritis according to the OA staging tool.

During grading of the dog, discomfort in different positions was assessed, as well as posture and motion that was be observed. On the other side, the grading of the joints was assessed by pain response upon manipulation, a general physical examination of the joint and possibly radiographs.

After that, the staging of the patients was conducted. Stage 0 and 1 are preclinical, which means they are clinically normal. Stage 0 hast no OA risk factors, Stage 1 has OA risk factors.

Stage 2 is when the patient shows mild clinical signs, stage 3 moderate clinical signs and stage 4 are severe clinical signs. (26)

1.2.4. Problems in Diagnosis

During the diagnostic procedure of Osteoarthritis, various problems can lead to a wrong diagnosis.

One of the most common problems are variations in severity of physical and/or clinical signs. Many joints with severe arthritis show physical thickening of the joint and reduced range of motion but correlation with lameness is very poor. Differentiation between subclinical arthritic disease and significant arthritis must be done with thorough examination and analysis of gait and posture.

Another problem is that joints are not examined due to the dog having systemic signs of inflammation such as fever, weakness, lethargy. Often the systemic inflammation is treated but not the local inflammation in the joints.

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15 The last problem is pain - it is one of the most prominent clinical signs of Osteoarthritis. Cartilage lacks nerve endings so only cartilage erosions should not be painful. In the joint capsule, ligaments and bone however, have numerous nerve endings that can cause serious pain which can be stimulated by a number of types of mechanisms. (18)

1.3. Treatment of Osteoarthritis

There are different approaches to the treatment of Osteoarthritis. Understanding every option is important.

1.3.1. Medical Treatment of Osteoarthritis

For most veterinarians, Osteoarthritis is and will be a disease that can only be managed but not cured. Even controlling it can be very difficult and takes time and commitment from the owners. Articular cartilage has only a limited potential to replace damaged matrix with new matrix with a complete restoration of the structure and function. Therefore, it is more realistic to expect a limited repair of the matrix which is usually a fibrocartilage matrix. Unfortunately, fibrocartilage matrix is inferior to normal hyaline cartilage matrix – both in structure and its ability to withstand normal weight bearing loads.(17,18)

1.3.1.1. Non-steroidal anti-inflammatory drugs

NSAID’s act predominantly by blocking the inflammatory effects of prostaglandins by inhibiting the breakdown of arachidonic acid by cyclo-oxygenase and lipoxygenase. Two different kinds of cyclo-oxygenase forms exist. COX-1 is the endogenous form and COX-2, the inducible form. COX-1 is responsible for the production of protective prostaglandins. These prostaglandins help to maintain the integrity of the gastric mucosa and vascular endothelium. (17,18)

The COX-2 form of cyclo-oxygenase is part of the inflammatory response and is responsible for the production of inflammatory prostaglandins. Many common NSAIDs block COX-1, which then leads to side effects such as gastrointestinal bleeding and renal failure. When using NSAIDs as a treatment for Osteoarthritis, it is important to make sure that COX-1 is not blocked. (18-20)

Despite the known side effects, NSAIDs remain the first line of treatment for veterinarians when it comes to Osteoarthritis. The choice of drug is for many veterinarians, a personal preference. Usually NSAIDs such as phenylbutazone, carprofen, meloxicam, tepoxalin, firocoxib, deracoxib and etodolac are used. The side effects, such as gastrointestinal bleeding varies with choice of drugs, as discussed before, but also when the dosage is higher than normal dose rate. (18,19)

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16 relieving pain, they can permit a greater use of the joint motions and therefore increase wear and tear. This can lead to a worsening of the condition. (18, 21,22)

Another important factor when using NSAIDs as a treatment for Osteoarthritis is the prescribing practice. Some veterinarians recommend intermittent therapy to give medication as needed while others recommend a continuous therapy.(18, 19)

Benefits of a continuous therapy are a better management of the pain, greater improvements in motion mobility and a potential slowing of the disease process through improvement of joint usage. With an improvement of the joint motion, secondary problems such as muscle atrophy can be avoided. (19)

The side effects of continuous medication include tolerance to the drug over time, an increase in adverse events associated with the use of the drugs, as well as compliance issues. (18-21)

Research has shown that COX inhibitors can inhibit the central sensitization which facilitates nociceptive throughput and amplifies signals resulting in greater perceived pain. Therefore, if the use of NSAID over time lead to a reduction in central sensitization, there should also be a progressive reduction in pain perceived by the animal. (18-24)

There is accumulating evidence that central sensitization can drive the progression of the disease and that downward modulation of the central sensitization can result in decreased joint pathology. (19, 23) Furthermore, a direct effect of NSAIDs on the joint may result in the reduction of disease progression. One reason for this can be due to the prevention of nitric oxide-induced cell death. Studies have shown that the cartilage in osteoarthritis has a greater number of apoptotic chondrocytes than normal cartilage in healthy animals. COX-2 has been shown to significantly inhibit nitric oxide- induced cell death. As a result of this, nitric oxide may play an important component in the pathogenesis of Osteoarthritis. (19, 24). Although, in theory, a continuous use of NSAIDs has many benefits, no studies have evaluated the comparative efficacy of continuous versus intermittent NSAID therapy in canine osteoarthritis. (19, 20)

1.3.1.2. Disease modifying osteoarthritic drugs

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17 analgesic effects. In a recent study, a canine IL4-10 fusion protein was tested and evaluated in vivo.(10, 30-35) In this study, six weeks after Osteoarthritis induction, dogs were intra-articularly injected weekly for ten weeks, with either IL4-10 fusion protein or phosphate buffered saline. After ten weeks, cartilage and synovial tissue samples were analyzed by histochemistry and biochemistry. (30-35)

The results showed that intra-articular injections with human IL4-10 fusion protein led to a formation of antibodies which blocked its functional activity. As a result, a canine IL4-10 fusion protein was developed to overcome this problem and inhibited LPS-induced TNFα production and increased proteoglycan synthesis of cartilage. To sum up the study, human IL4-10 fusion protein is immunogenic in dogs. On the other hand, Canine IL4-10 fusion protein can produce and diminish canine blood cell inflammatory activity and increase the ability of chondrocytes to manufacture new matrix components. This results in canine IL4-10 fusion protein showing a promising DMOAD activity in vivo.(35-38)

1.3.2. Platelet-Rich Therapy as a Treatment of Osteoarthritis

As previously established, osteoarthritis is a chronic degenerative joint disease. The articular cartilage is subject to progressive destruction, thinning and eventual wearing, which therefore results in painful, limited joint movement. (32, 37-39)

This degeneration of the articular cartilage is mainly due to changes in the activity of chondrocytes in favor of catabolic activity. This also involves other joint tissues, sclerosis and edema in the subchondral bone and intermittent inflammation of the synovium. (32, 40-41)

1.3.2.1. Development of PRP

The first published description, when science focused on developing new biological glues, of the development and use of platelet-rich plasma were in the early 1990s. In the early descriptions, PRP was described as a volume of plasma that has a platelet count above baseline. This suggests a mixture of the acellular, liquid portion of blood which contains proteins for clotting and bioactive molecules for wound repair and platelets including cytokines and growth factors. In more recent research, when the term platelet-rich plasma was used more frequently, it included more final products. These products are based on their leukocyte and fibrin content. (32, 27)

1.3.2.2. How to create platelet-rich plasma

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18 cytokines, thrombin and other growth factors with inherent biological and adhesive properties. (31, 32)

Platelet-rich plasma can be prepared by either one-step or two-step-centrifugation. The effects of the two different methods are still considered controversial. (32, 36, 39-41)

1.3.2.3. Bioactivity of platelet-rich plasma

Platelets contain more than 800 proteins with many post-translational modifications for more than 1.500 protein-based bioactive factors. The effect of the proteins has been thoroughly studied. Fibrin acts as a biological glue, the proteins in platelets have antibacterial and fungicidal effects, coagulation factors and membrane glycoproteins. This increases the synthesis of interleukins and chemokines which influence inflammation.

By delivering a broad range of growth factors and active molecules such as chemokines, arachidonic acid metabolites, nucleotides, ascorbic acid and extracellular matrix proteins, to the injured site, platelets participate greatly in the healing process. (32, 38, 39)

1.3.2.4. The effect of platelet-rich plasma in osteoarthritic joint

The cartilage in joints has special nutritional requirements which makes it very difficult to repair spontaneously because of the lack of blood supply. Platelet-rich plasma provides those nutritional requirements, as well as providing an antibacterial, anti-inflammatory, analgesic, coagulating and hemostatic effect. It also increases glycosaminoglycan levels and chondrocyte synthesis of the cartilage matrix. This is especially important for stem or primary cell migration, differentiation, as well as wound healing.

The whole healing process of osteoarthritis can be divided into three phases. Phase one is inflammation, phase two is cell proliferation and phase three is remodeling. Platelet rich plasma was designed to be injected into multiple painful sites of ligaments, tendons and adjacent joint spaces. This then promotes tissue repair and growth through a natural healing cascade. The growth factors are released from platelets granulates and induce chemotaxis, angiogenesis, proliferation, cell migration, differentiation and matrix production. The hyaluronic acid secretion is increased, as well as the release of angiogenic growth factors.

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2. Material and Methods

2.1. Experimental animals

The study was conducted from 2019 to 2020 in cooperation with different small animal clinics in Vienna, Austria.

Most of the dogs were privately owned, however, some of them were living in the animal shelter at the time of testing. All animals had constant access to fresh water and were fed regularly by the owners.

For injection of the platelet rich plasma, some of the dogs had to get a light sedation with Acepromazine (0.02mg/kg) to make the procedure less stressful for them. For the groups with NSAIDs and the control group with no treatment, no sedation or additional anesthesia or medication was necessary. All testing was consistent with ethical guidelines and with the animals’ welfare as the highest priority.

Fig.1: Map of Austria with Vienna marked

2.2. Study design

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20 patient was suitable for the study. The criteria for this, was that the stage of Osteoarthritis be at least a Stage 2, which corresponds to mild osteoarthritis. If the patient did qualify for the study, the findings and evaluation, as well as possible treatment options were discussed with the owner. The owners of the patients did have a full understanding of the severity and best treatments for their pet and did decide if they want to participate in the study and if so, which treatment plan they want to follow.

Most owners decided between NSAIDs and PRP therapy. Following this examination and discussion, the relevant candidates were divided into 3 groups for the purpose of the research; group 1 received the PRP therapy as treatment, group 2 received the standard treatment with NSAID’s, and group 3 (control) received no treatment. The dogs in the control group with no treatment were mostly from the animal shelters in Vienna, who could not at the moment afford treatment for the dogs. Some of the owners, who decided to go for NSAIDs or no treatment, also considered the length of time involved in the treatment. Since patients participating in the PRP therapy had to come back after three months for a second round of treatment, the time consumption of this, as well as the financial factor, influenced the decision of the owners.

The PRP group received two treatments, one after the initial examination and after staging the Osteoarthritis with the OA staging tool, and one three months after the first treatment. After six months, the final results were evaluated.

The NSAIDs group received oral Carprofen at a rate of 4mg/kg SID as a medication and came back to the practice after two weeks of treatment to assess how the dogs’ system handles the medication. None of the patients had any problems with the medication and were able to continue treatment for the remainder of the study period. After a total of six month, the patients came back for a final checkup.

The group with no therapy also came back for final examination for results after six months. The owners were told to came in as soon as they notice any further symptoms of worsening of Osteoarthritis or the general wellbeing of the dog. In between the six months, none of the patients in group three came back for further examinations.

Stage 0 Clinically normal, no OA risk factors

Stage 1 Clinically normal, but OA risk factors present Stage 2 Mild OA

Stage 3 Moderate OA Stage 4 Severe OA

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21 2.3. Evaluation of patients and assessment of suitability for the study

Potential candidates for the study were examined using the system of the Osteoarthritis staging tool. Before any examination, the history of the dog is being taken, which already indicates potential risk factors for Osteoarthritis.

After that, a general examination of the dog was made to assess the animal’s general health and wellbeing. This included the gait and general movements, as well as avoidance of pressure on any body part. During this stage, the body weight score with a scale from 1-9, with 1-3 being underweight, 4-5 being ideal weight, 6-9 being overweight.

As a second step, the affected joint was thoroughly assessed. This includes an orthopedic examination with assessment of the movement range, pain responses and management of pressure on the joint.

After all examinations were completed, the Osteoarthritis was categorized into one of the 5 stages of the OA staging tool. In this study, only patients with Osteoarthritis in the Stifle joint or Elbow joint were accepted as patients for the study.

After examination of the patients, assessment of the grade of Osteoarthritis using the internationally recognized Osteoarthritis staging tool, the case was evaluated for suitability for the study. To be suitable, a minimum Stage of Stage 2 was required.

If the patient was suitable for the study, the study process and treatment options were discussed with the owner. The Owners were thoroughly informed about every treatment option and the literature study behind it. After that, the owner decided which treatment works best for them and from that the patients were divided into three groups. The groups were assessed individually, but over the same amount of time of six months.

None of the 30 canine patients had any history of other disease in the last 12 months. No other measures or instructions like movement restriction, physiotherapy or weight loss were given to the owners.

2.4. Patients of each group

2.4.1 Patients of group one

Group one of patients consists of ten dogs between the ages of 3 to 12 years. The breeds are different, including a mixed breed. As well as the weights of the patients which varied between the lightest of 4,1 kg and 38,5 kg of the heaviest.

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22 Half of the canine patients of this group presented with OA in the Stifle joint, which left the other 50% with presentation in the elbow joint.

The body score, with obesity starting at a score of 6, showed that four patients were overweight. The rest of six patients had normal weight, which leaves none of the patients to be underweight.

Table 1: Patients in Group PRP

2.4.2. Patients of group two

Group two of patients consists of dogs between the age of 3 years and 12 years. The breeds vary from mixed breeds to small breeds like Yorkshire terrier to large breeds such as Saint Bernhard. Therefore, the weights vary as well with the lightest dog with 3,1kg and the heaviest with 49,7kg.

Name Breed Weight Age

Stage before Stage after treatment Location Body weight score Daisy American

Staffordshire 31,9kg 8y 3 3 Stifle joint 6

Rocko Pug 12,5kg 10y 3 3 Stifle joint 6

Bernd Saint Bernhard 49,7kg 4y 3 3 Stifle joint 5

Maya Rottweiler 41,5kg 9y 2 1,5 Elbow joint 5

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23 Nova

Labrador

Retriever 24,9kg 3y 2 1,5 Elbow joint 5

Balou Mix 16,3kg 4y 2 2 Elbow joint 7

Sam

Labrador

Retriever 27,9kg 4y 2 2 Stifle joint 5

Max Maltese 4,8kg 12y 3,5 3 Stifle joint 6

Bella Yorkshire terrier 3,1kg 9y 3 3 Elbow 5

Table 2: Patients in Group NSAIDs

Before treatment, four patients had Stage 2 Osteoarthritis. After treatment, two of them decreased to a Stage 1-2 while two patients stayed at the same Stage with no improvement observed. The worst Stage was a Stage 3-4 in 12-year-old Maltese Max before treatment. After the last treatment, his Osteoarthritis improved to a Stage 3.

When looking at the location of the OA, 50% of patients presented with Osteoarthritis in the Stifle joint and the other 50% in the elbow joint.

The body score for six canine patients was normal, four of the patients in this group were overweight.

2.4.3. Patients in group three

In group three, the youngest patient was 4 years old and with 35,1kg also the heaviest. The oldest patient was 12years old and as well, with 4,3kg, the lightest of the subjects in this group.

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24

Table 3: Patients in group no treatment

The lowest stage in this group was a stage 2, which after six months, remained a stage 2. Six of the dogs scored a stage 3 on the OA staging scale, with three of them worsening to a stage 3-4 after no treatment. Stage 4 was in three of the patients, which stayed the same after no treatment was received.

In five of the patients, the location of OA was in the Elbow joint. For the other 50% of the group, it was located in the Stifle joint.

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25 2.5. Collection and Processing of Blood

Blood samples for taken from the PRP group for processing of the blood for further treatment. Location of blood sampling was Vena femoralis or Vena saphenous.

Fig. 3: Material for Blood collection

If sedation was necessary, blood was taken while venous catheter was placed at Vena cephalica. Sedation was required in two of the dogs in this group. For the sedation, Acepromazine (0.02mg/kg) was administered intramuscularly. After the sedation took effect, the venous catheter was placed and a minimal dosage (3mg/kg) of Propofol was administered to prolong the mild sedation of the animal throughout the treatment. After the treatment, the dogs were back to full consciousness within 10 minutes.

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26

Fig.4: Blood sample in Centrifuge

After separation, the PRP was drawn into the smaller syringe without aspirating the buffy coat or red blood cells. then the PRP was ready for injection into the affected joint. Mostly four to five different injections were made around and into the joint.

This PRP contains more than 800 proteins with many post-translational modifications for more than 1.500 protein-based bioactive factors. The effect of the proteins has been thoroughly studied. Fibrin acts as a biological glue, the proteins in platelets have antibacterial and fungicidal effects, coagulation factors and membrane glycoproteins. This increases the synthesis of interleukins and chemokines which influence inflammation. (32, 38)

Fig.5: Blood after centrifugation with PRP, buffy coat and red blood cells.

2.6. Statistical Analysis

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27

3. Results

3.2. Group one – Plasma Rich Platelet Group

3.4.2. Statistical analysis of group one

Fig.6: Statistical test results PRP group

The sign test revealed a significant change between first and last treatment session on the 0-4 arthritis scale, p = 0.002. The median on the Osteoarthritis scale of the first examination was higher (MD = 3,5) than the median of the last treatment (MD = 2,25).

90% of subjects in this group showed a clear reduction of clinical signs of osteoarthritis following the administration of PRP therapy. The statistical analysis revealed that on average the subjects grade using the OA staging tool reduced by 1.25.

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 1 2 3 4 5 6 7 8 9 10

Median

Stage before Stage after treatment

M

edi

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28

3.5. Group two – NSAIDs therapy patients

3.5.2. Statistical analysis of group two

Fig. 7: Statistical test results NSAID group

The sign test revealed no significant change between first examination and treatment and last treatment and examination session on the 0-4 Osteoarthritis staging tool scale, p = 0.250. The median on the scale of the first treatment was the same as the median of the last treatment (MD = 3)

70% of the subjects in the 2nd_{group showed no change in clinical signs of OA, remaining at the same}

level on the OA staging tool. The remaining 30% showed possible signs of improvement. The statistical analysis revealed that the average grade of subjects on the OA staging tool did not change following treatment using NSAID therapy.

0 0.5 1 1.5 2 2.5 3 3.5 4 1 2 3 4 5 6 7 8 9 10

Median

M

edi

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29

3.6. Group three – no treatment

3.6.2. Statistical analysis of group three

Fig.8: Statistical test results no treatment group

The sign test revealed no significant change between first and last treatment and examination session on the 0-4 Osteoarthritis staging tool scale, p = 0.250. The median on the scale of the first treatment (MD = 3) was similar to the median of the last treatment (MD = 3,5).

30% of the group three subjects worsened over the period of six month by half a stage. Statistically this cannot be stated with confidence, nevertheless, during examination, the overall wellbeing of the animal did show a decline.

3.7. Comparison of the three groups results

To illustrate the differences of the groups better, a comparison of the results is necessary. First, we will look at the differences of the median before treatment, second at the differences of the median after treatment and third at changes in median for each group.

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 1 2 3 4 5 6 7 8 9 10

Median

M

edi

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30

Fig. 9: Median of groups before treatment

The difference between the groups varies greatly. Before any treatment, the median of each group was between 3,5 for group one and 3 for group two and three.

Fig.10: Median of groups after treatment

After the treatment and final examination of the patients in each group, the median of group one decreased to 2,25, the median of group two stayed the same with 3 and the median of group three increased to a 3,5 which does mean a worsening of the condition in patients was seen.

2.7 2.8 2.9 3 3.1 3.2 3.3 3.4 3.5 3.6

Group 1 Group 2 Group 3

Median of groups before Treatment

M edi an 0 0.5 1 1.5 2 2.5 3 3.5 4

Group1 Group2 Group3

Median of groups after treatment

M

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31

Fig. 11: Differences in median before and after treatment of groups

To illustrate the differences of the median of each group better, the differences between first and last treatment median was calculated. For group one, we can see that -1,25 was achieved, which shows a significant improvement in the condition of patients. Group two did not have any changes; this means that the condition of the patients stayed the same. In group three, with +0,5, some worsening can be seen in patients.

This correlates with the findings of the study. Dogs, who were treated with NSAIDs, did not experience worsening of osteoarthritis.

3.8. Difference of treatment effectiveness compared to location of the

Osteoarthritis

For this part, patients of every group were further divided into two subgroups to evaluate a possible correlation between the treatment’s effectiveness compared to the location of the effected joint. Furthermore, the correlation was measured for each group with Correlation Test between bivariant variables using SPSS Statistics Program. Every result between -0,1 and +0,1 is a mild correlation, -0,3 and +0,3 a medium correlation and -0,5 and +0,5 a very significant correlation. 3.6.1. Patients of Group 1 with OA in Stifle Joint

In Group 1, who received PRP therapy, half of the patients Stifle Joint was affected by OA. -1.25 0 0.5 -1.5 -1 -0.5 0 0.5 1

Group 1 Group 2 Group 3

Differences in median before and after

treatment

M

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32

Fig. 12: Differences in Median Stifle Joint Patients Group 1

The sign test revealed significant differences between the stages before and after treatment in patients with an affected stifle joint with p= 0,031. The median before treatment was higher (MD=3,5) than the median after the last treatment (MD=2,25). This means, that the PRP therapy was effective for patients with an affected stifle joint and can be proven.

3.6.2 Patients of Group 1 with OA in Elbow Joint

The other half of Group 1 patients presented an affected elbow joint with OA.

Fig. 13: Differences in Median Elbow Joint Patients Group 1

With an p-value of p=0,063 there was no statistically significant change between before treatment and after treatment. Although the median before treatment (MD= 3,5) was higher than the

0 0.5 1 1.5 2 2.5 3 3.5 4

Median Stifle Joint Patients Group 1

Before treatment After treatment

M edi an 0 0.5 1 1.5 2 2.5 3 3.5 4

Median Elbow Joint Patients Group 1

M

edi

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33 median after treatment (MD= 2,3), the effectiveness of PRP therapy in patients with OA presented in the elbow joint cannot be proven.

3.6.3 Patients of Group 2 with OA in Stifle Joint

In Group 2, half of the patients presented with OA in the stifle joint. During statistical analysis, a p-value from p=1 was seen which does not show a significant bettering in patients of this group. The median of this patients only improved minimally with MD= 2,9 before treatment and MD=2,8 after treatment.

Therefore, no significant effect can be seen for patients with stifle joint OA receiving NSAID treatment.

The general Correlation for PRP therapy and Location was r=0,2. This shows a mild correlation between treatment and Location in the joint.

3.6.4 Patients of Group 2 with OA in Elbow joint

50% of Group 2 presented with OA in the elbow joint. The p-value with p=0,5 shows no significant change between the Osteoarthritis stages before and after treatment.

2 2.5 3 3.5 4

Median Stifle Joint Patients Group 2

M

edi

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34

The media for this subgroup also only improved minimally with MD=2,4 before treatment and a MD= 2,2 after the last treatment. The effectiveness of NSAID treatment for patients with OA in the elbow joint can therefore not be proven.

The correlation with r=0,21 does show a mild correlation between Joint Location and treatment effectiveness.

3.6.5 Patients of Group 3 with OA in Stifle joint

In the last group, which did not receive any treatment, 50% of patients presented with OA in the stifle joint. With a p-value of p=0,5 and with both median before and after treatment of MD= 3,6, no bettering nor worsening of the disease without treatment in the stifle joint can be seen.

0 1 2 3 4

Median Elbow Joint Patients Group 2

M edi an 0 0.5 1 1.5 2 2.5 3 3.5 4

Median Stifle Joint Patients Group 3

M

edi

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35 3.6.6 Patients of Group 3 with OA in Elbow joint

Half of the patients in group 3, presented with OA in the elbow joint. The p-value for this subgroup was p=0,5 and is therefore not significant. The median before treatment MD= 2,8 was a little bit lower than the median after treatment MD= 3,1. This shows a slight worsening of the OA stages in this subgroup. Therefore, the effectiveness of no treatment in OA in the elbow joint, cannot be statistically proven.

The correlation between joint location and treatment was at r=0,65 which shows a high correlation for this group.

3.9. Difference in treatment effectiveness compared to the age of the patients

For this analysis, patients of each group were divided into two subgroups. Patients over the age of 10 years old, or for larger breeds the age of 9 years old, were put into geriatric group. Patients under the age of 9 or 10 years old, were put into the group of middle-aged dogs. After dividing, the effectiveness of different treatments were assessed.

3.7.1. Difference in treatment effectiveness in geriatric patients Group 1

In this group, three patients were over the age of 10 years and therefore suitable for this subgroup. All patients still received the same treatment plan with PRP.

The p-value for this group was p= 0,25. Even though the median before treatment MD=3,3 is higher than the median after treatment MD=2,3, no statistically significant effectiveness of PRP therapy in geriatric patients can be proven.

0 0.5 1 1.5 2 2.5 3 3.5 4

Median Elbow Joint Group 3

M

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36

Fig. 18: Differences in Median Geriatric patients Group 1

3.7.2 Difference in treatment effectiveness in middle-aged patients Group 1

In this subgroup, seven patients from group 1 were assessed. All patients were under the age of 10 years old.

During statistical analysis, the p-value with p=0,008 was calculated. This shows a significant improvement in OA in middle-aged dogs.

Fig. 19: Differences in Median middle-aged patients Group 1

The median MD=3,6 before treatment and MD= 2,3 after treatment, also show an improvement in this subgroup receiving PRP therapy.

The correlation for this group is r=0,19, which only shows a mild correlation between age and treatment effectiveness. 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

Median Geriatric patients Group 1

M edi an 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5

4.0

Median Middle aged dogs Group 1

Before treatment After treament

M

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37 3.7.3 Difference in treatment effectiveness in geriatric patients Group 2

This subgroup contains of four dogs. One of the patients is 9 years old but due to being a Rottweiler with 41,5kg, it was decided that he is a better fit for the geriatric patients group. The other three patients ages very from 10 to 12 years of age.

The p-value for this group was p=0,5. Also the median before treatment MD= 2,9 and median after treatment MD= 2,6 did not show any significant change in the disease in geriatric patients receiving NSAID therapy.

Fig. 20: Differences in Median geriatric patients Group 2

3.7.4 Difference in treatment effectiveness in middle aged patients Group 2

Six patients of group 2, who received NSAID therapy, were selected to be in this subgroup. During statistical analysis, a p-value from p=1 was calculated. The Median before treatment MD= 2,5 and after treatment MD= 2,4 show no significant change. Therefore, NSAID treatment effectiveness in middle aged patients cannot be proven.

The correlation for this group is r= 0,79, which does show a high correlation between age and treatment effectiveness. 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

Median geriatric patients Group 2

Before treatment After treamtent

M

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38

3.7.5 Difference in treatment effectiveness in geriatric patients Group 3

From group three, which patients received no treatment, four dogs were chosen for this subgroup. The p-value for this subgroup was p=1 and median before and after treatment stayed the same with MD= 3,8. Therefore, no significant effect of no treatment in OA in geriatric patients can be seen.

Fig. 22: Differences in Median geriatric patients Group 3

3.7.6 Difference in treatment effectiveness in middle aged patients Group 3

The remaining six patients of group three were chosen for this subgroup of middle-aged dogs with ages varying from 4-8 years.

0 0.5 1 1.5 2 2.5 3 3.5 4

Median middle aged dogs Group 2

M edi an 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

Median Geriartric patients Group 3

M

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39 The p-value calculated for this subgroup was p=0,25 and median before treatment MD=2,8 and after treatment MD= 3,1 as well show no significant worsening in middle aged dogs with OA who received no treatment.

The correlation for this group is r=0,75 and it shows a high correlation between age and no treatment.

3.10. Difference in treatment effectiveness compared to the weight of the

patients

For this analysis, a body score index was used to determine the body status of the canine patients. The score reached from 1-9, with 1-3 being underweight, 4-5 having ideal weight and 6-9 being obese.

3.8.1 Difference in treatment effective in obese dogs of Group 1

In group 1 four patients presented with a body score over 5. Three of the patients had a score from 6 and one a score of 7.

The statistical analysis showed a p-value from p=0,125, which proves no significant bettering of OA in patients who are obese.

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

Median Middle aged dogs Group 3

M

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40

Fig. 23: Differences in Median obese patients Group 1

The difference in median, with MD=3,25 before treatment and MD=2,25 after treatment, show some bettering in OA. However, this cannot be statistically proven and therefore PRP therapy did not show a significant bettering in obese dogs.

3.8.2 Difference in treatment effective in normal weight dogs of Group 1

Six patients of Group 1 are in this subgroup. The p-value was evaluated for this group and with p=0,031 it shows a significant effect of the treatment with PRP in normal weight dogs.

Fig. 24: Differences in Median normal weight patients Group 1

Median before treatment with MD= 3,5 and after treatment with MD= 2,25 also illustrate the effectiveness of the treatment for normal weight dogs.

The correlation for this group in regards of weight is r=0,61 and this shows a high correlation.

0 0.5 1 1.5 2 2.5 3 3.5 4

Median Obese dogs Group 1

M edi an 0 0.5 1 1.5 2 2.5 3 3.5 4

Median normal weight dogs Group 1

M

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41 3.8.3 Difference in treatment effective in obese dogs of Group 2

Four of the ten patients in group 2 were obese and therefore qualified for this subgroup. Patients in group 2 all received treatment with NSAIDs. With a p-value of p=1, no significant bettering in OA can be seen in obese dogs of group 2.

The median difference of this group was also very low with MD= 2,9 before treatment and MD= 2,8 after treatment.

In this subgroup, six patients of group two, who received therapy with NSAIDs, were put. The p-value with p=0,5 showed no significant bettering of OA with NSAIDs in normal weight dogs. The median in this group stayed the same before and after treatment with MD=2,5.

The correlation for this group is r=0,073. This is a very mild correlation between the treatment effectiveness and weight.

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5

4.0

Median Obese dogs Group 2

M edi an 0 0.5 1 1.5 2 2.5 3 3.5

4

Median normal weight dogs Group 2

Before treatment After treatment.

M

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42 3.8.5 Difference in treatment effective in obese dogs of Group 3

In this subgroup, four patients of group 3, who received no treatment for OA, were put. The median before treatment of MD=3 and after treatment MD=3,3 showed a slight worsening in OA in obese patients. The p-value of p=1 showed no significant bettering between the six-month period without any treatment in obese patients.

The remaining 60% of group three were of a normal weight and therefore placed in this subgroup. The p-value of p=0,5 showed no significant change in OA over the period of six month with no treatment in normal weight dogs.

The median before treatment with MD= 3 and after treatment of MD= 3,5 showed a slight worsening of OA in the patients of this group.

The correlation for this group is r=0,64, which does show a high correlation between weight and treatment effectiveness.

0 0.5 1 1.5 2 2.5 3 3.5

4

Median obese dogs Group 3

M edi an 0 0.5 1 1.5 2 2.5 3 3.5 4

Median normal weight dogs Group 3

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43

4. Discussion of Results

When comparing the three groups of patients in general, the statistical analysis showed a significant improvement in the group of dogs which received Platelet Rich Plasma Therapy. During the six-month period, the Osteoarthritis in the patients got significantly better and their general condition showed real improvement. This is shown by the overall decrease in the stage assigned to the subjects using the OA staging tool. The median of patients in this group decreased from M=3,5 to M=2,25, which means a difference from 1,25 in the median can been seen in group one. This is also shown by the p-value of p=0,002.

Platelet-rich plasma is rich in growth factors and many different protein-based bioactive factors. As for example, Fibrin acts as a biological glue. On the other hand, the proteins in PRP have antibacterial and fungicidal effects, as well as coagulation factors and membrane glycoproteins.

By having this broad range of growth factors and other active molecules, chemokines, arachidonic acid metabolites, nucleotides, ascorbic acid, and extracellular proteins delivered to the injured site greatly aids in the healing process. (32, 38)

Therefore, platelet-rich plasma does not only provide anti-inflammatory properties and pain relief, it also promotes healing of the joint tissue and can improve the condition of osteoarthritis. This can be seen in the results of the study over a six-month period.

On the other hand, the patients receiving treatment with NSAIDs, which is a very common treatment for Osteoarthritis, did not show any improvement. It is also important to note, that, even though their condition did not improve, it also did not get worse. With a median at the beginning of M=3 and the same median after treatment, no differences were seen in this group. This would indicate that NSAID therapy halts the progression of the disease. Those finding correlate with studies that have shown that the cartilage in osteoarthritis has a greater number of apoptotic chondrocytes than normal cartilage in healthy animals. COX-2 has been shown to significantly inhibit nitric oxide- induced cell death. This direct effect on the joint may result in the reduction of disease progression as was seen during the study but does not have a healing effect. (19, 24)

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44 These results are in line with the theoretical findings. NSAIDs have been the first line treatment option for many veterinarians over the years. It provides pain relief, anti-inflammatory properties and might reduce the disease progression by preventing nitric oxide-induced cell death. (19) Thus, not having any treatment at all does progress the disease over time and does not provide any chance of improvement.

When comparing the different treatment options in regards of the location of OA in the joint, patients who had the disease in the stifle joint and received PRP did show a significant improvement with a p-value from p=0,031 and a median change from MD=3,5 before starting treatment to MD=2,25 after the treatment. On the other hand, patients who also received PRP therapy but had OA in the elbow joint, did not show a significant improvement with a p-value from p=0,063 and median from MD= 3,5 before and MD=2,3 after treatment. This shows, that PRP therapy did not work when the disease is located in the elbow joint but did have a positive effect when located in the stifle joint.

The correlation showed a mild correlation between treatment effectiveness with PRP and the location of the joint with r=0,2.

These results could be due to the mechanics of the joints. During movement, the canine has an easier time balancing a reduction on the tear of the joint when it comes to the hindlimbs. This may indicate that the therapy success is also correlated with reduction of mechanical weight and movement on the effected joint. (9, 10)

For patients, who received NSAID treatment or no treatment, the location of the OA did not make a difference in the outcome. Patients in group 2 with OA in the stifle joint had a p-value from p=1. Dogs with OA in the elbow joint and receiving NSAID treatment had a p-value from p=0,5. Both do not show a significant improvement to the disease. The correlation between this group was r=0,218, which shows a mild correlation.

For patients in group 3, who did not get any treatment, the p-value or OA in the stifle and elbow joint was at the same with p=0,5. This shows no difference in the progression of the disease in relation to the location of OA. Nevertheless, it did show a high correlation with r=0,655.

When comparing the effectiveness of PRP in geriatric patients to middle-aged dogs, it showed that in geriatric patients, with a p-value of p=0,25 and a median before treatment with MD=3,3 and after treatment with MD=2,3, there was no significant improvement.

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45 patients. The correlation value for this treatment in regards of the age was 0,19, which shows a mild correlation.

This correlates with theoretical studies, which show a direct correlation between age and osteoarthritis. This does not mean, that older dogs automatically get OA, but it does show that with a certain age, the risk of OA is greater. Therefore, also the treatment becomes less effective since age does change the musculoskeletal system and changes in the joint tissue due to formation of advanced glycation end-products. (44)

For patients with NSAID treatment, there was no significant improvement regardless of the age. Geriatric patients had p-value from p=0,5 and median before treatment with MD=2,9 and after treatment with MD=2,6. The subgroup with middle-aged dogs had a p-value from p=1 and median before treatment with MD=2,5 and after MD=2,4. This shows no significant improvement in both subgroups and it can therefore be said, that the age does not have an effect on the effectiveness of NSAID therapy in OA in dogs. When looking at the correlation, an r-value of r=0,79 shows a high correlation between age and this treatment option.

For patients who did not receive any treatment, the p-value in geriatric patients was p=1 and in middle aged dogs p=0,25. This also shows no improvement or worsening of the condition in regards of age. The correlation in this group between age and no treatment was r=0,75, which shows a significant correlation.

After theoretical research, it is no surprise that the treatments do not improve the condition since it was established before, that NSAIDs can only slow down the progression of the disease but not show any healing properties. (19)

To study the influence on the effectiveness of the treatment according to weight, patients were again put into two subgroups. For obese dogs who did receive PRP therapy, the p-value was at p=0,125 and MD=3,25 before treatment and MD=2,25 after treatment. This shows no statistically significant improvement of the condition when the patient is obese.

For normal weight dogs, the p-value was at p=0,031 and median before treatment MD=3,5 and after treatment at MD=2,25, which does show a significant improvement. As a conclusion, it can be said that weight does influence the effectiveness of PRP therapy. The correlation test showed a r-value of r=0,61, which means a high correlation between weight and the effectiveness of PRP therapy.

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46 after treatment. This groups r-value is at r=0,07, which does only show a very mild correlation between treatment effectiveness and weight.

For group 3, there were also no improvements or significant worsening of the disease seen in regards of weight. Obese patients had a p-value from p=1 and normal weight dogs p=0,5. When looking at the correlation, it does show a high correlation with r=0,647.

This would indicate that only in PRP therapy with normal weight patients an improvement can be seen. Therefore, weight does have an influence on the effectiveness of treatment when it comes to PRP therapy but not for other treatment options.

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47

Conclusion

1. Comparing the treatment option showed, that PRP therapy showed a significant improvement (p=0,002) in the affected joints. NSAIDs therapy (p=0,250) and the control group (p=0,250) with no therapy showed no improvement.

2. In PRP therapy, a mild correlation between treatment effectiveness and joint location was seen with r=0,2. The correlation between NSAID therapy and location of OA was r=0,218, which shows a mild correlation. The correlation for the control group was r=0,655. This shows a high correlation between location and no treatment.

3. The correlation between treatment effectiveness of PRP and weight was very high with r=0,61. The correlation for NSAID showed a mild correlation at r=0,07. For the control group the correlation was high at r=0,647,

LITHUANIAN UNIVERSITY OF HEALTH SCIENCES VETERINARY ACADEMY