The College of Animal Physiotherapy

Diploma in Animal Physiotherapy

Module 4

Orthopaedics

Copyright: The College of Animal Physiotherapy Ltd 2011

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AIMS

To provide an overview of common orthopaedic conditions and the correct

physiotherapy treatments.

To provide students with an understanding of the fundamentals of the bones

and joints and their relevance to physiotherapy.

To provide students with the information to make the correct decisions as to

the most beneficial application of physiotherapy.

OBJECTIVES

At the end of this module you should be able to;

Describe the make-up, functions and types of bones and label a diagram of a

long bone.

Describe how bones are built and maintained

Describe the sequence of bone development

Identify the different types of fractures and describe fracture repair

Describe the components of a joint

Describe the process of arthritis

Identify common orthopaedic conditions and advise on correct physiotherapy

treatment

INDEX

Introduction 3

Section 1 – Bones and Fractures 5-16

BONES 5 Functions and types of bones 5 Bone growth 7 How bones are built and maintained 8 Structure of long bones 10 Bone development 12

FRACTURES 14 Types of fractures 14 Basic fracture healing 15 Treating fractures 16

Section 2 – Joints 17-22

Connective tissue, fibres, tendons and ligaments 17

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Joint anatomy 19 How does exercise effect joints 20 Inflammation of a joint 21

Section 3 – Orthopaedic Conditions 23-38 DJD 23 DOD 25

Osteochondrosis 26

COMMON EQUINE ORTHOPAEDIC CONDITIONS 27

Splints 27

Navicular disease 28

Pedal osteitis 30

Ringbone 31

Sidebone 31

Bone spavin 32

COMMON CANINE ORTHOPAEDIC CONDITIONS 33

Cruciate ligament rupture 33

Canine hip dysplasia 35

Legg-Calve-Perthes-Disease 36

Patella luxation 36

Physiotherapy treatments 36

Section 4 – Additional information 39-41 Synovial enlargements 39 Orthotics 39 Surgical techniques 39 Slings and carts 39 Prevention 40 Evaluation 41

Appendix – Terminology 42

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INTRODUCTION

Orthopaedics - “Branch of medicine dealing with correction of diseased or

injured bones or muscles ”

The body’s framework or skeleton is built of a network of over 200 bones - a

structural feat any architect would admire. The skeleton provides support and

protection for an organism. The internal support network of all vertebrates is made

up of cartilage and/or bone. Their organs and tissues are held together within the

skeleton, supported by connective tissue. From the inside out, bones serve a

multitude of functions, creating and carrying vital nutrients, such as blood and

minerals. Bone is incredibly strong, yet also light and flexible. Its two main

ingredients, calcium phosphate and calcium carbonate, provide strength and rigidity,

but the arrangement of its fibres, and the fact that bones are connected by pliant

muscles and joints, enable movement and flexibility. Just as our muscles strengthen

or weaken according to how we use them, bones gain mass and change shape when

we are active. Bone is vibrant, living tissue that constantly regenerates.

A large part of an animal physiotherapists’ work is related to orthopaedic conditions.

Much of this work is to the associated soft tissue and in the post-operative care and

rehabilitation. However, the rate of fracture repair can also be optimised with

physiotherapy.

Prevention is the best policy. The best way to deal with an orthopaedic condition is

to recognise when an animal is predisposed, and take steps to avoid the

development of a problem. This is not always possible but many cases could

be avoided or at least postponed with good management. Poor conformation is a

major cause of joint strain, and resulting orthopaedic changes. The physiotherapist

must address the overall picture when treating an animal. It is essential that these

faults are recognised so that steps can be taken to delay the inevitable. The

strain of underlying conditions will often start to show in other parts of the animals’

anatomy and this can be identified by the physiotherapist during treatment. Referral

back to the vet for further examination can result in swift treatment of a condition

which would otherwise have been more advanced before being detected.

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Injury to an area, if left untreated, can result in further injuries, often more serious

than the original. Along with good veterinary care, the intervention of physiotherapy

can stop this domino effect and in some cases avoid further complications.

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SECTION 1

BONES AND FRACTURES

BONES

Functions of Bone

Bone must have the following capabilities:

1. Support body weight and protect vital organs by withstanding both bending and

compressive forces.

2. Articulate with one another and transmit muscular forces to produce movement.

3. Repair and remodeling of its structure to accommodate for injury or for changes in

stress.

4. To act as the bodies largest reservoir of calcium and phosphorus.

5. To make blood cells in the bone marrow

Types of Bones

1. Long Bones - These have a shaft (the diaphysis) and two ends (epiphsis).

Examples include our leg and arm bones. These form from a cartilage precursor or

model.

2. Flat Bones - These do not have a shaft. Examples include our scapula.

3. Membranous Bones - These are formed between membranes without a cartilage

precursor. Examples include our cranial bones.

A Factory for Our Blood

In addition to its status as a crucial building block, bone is a factory and storage

facility for blood, consisting of vital red blood cells which carry oxygen from the lungs

to the body's tissues; white blood cells, which help the body to fight off infection, and

platelets, which enable the blood to clot.

Deep within all bone, tissue becomes soft and spongy, containing red or yellow bone

marrow, where 95 percent of the body's blood cells are made, including red and

white blood cells and platelets. In the center of bones such as ribs, vertebrae, pelvis

and skull bones lies red marrow. Each minute, red marrow delivers millions of red

cells, white cells and platelets into the bloodstream. Red and white blood cells and

platelets all grow out of one type of cell called a stem cell -a universal cell that can be

turned into any number of specialised cells that serve organs throughout the body.

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Red blood cell production is regulated by a hormone called erythropoietin, which

is produced in the kidneys. Erythropoietin will stimulate stem cells in the bone

marrow to produce more red blood cells when necessary.

The principal role of white blood cells is to protect the body against infection and to

fight infection when it occurs. There are three main types of white blood cells:

granulocytes, monocytes and lymphocytes, each of which can be generated when

the body faces invaders such as bacteria or viruses.

Platelets are the smallest type of blood cell. Usually inactive, they are stimulated in

the event of bleeding. When called upon, platelets will stick to blood vessel walls and

to each other to form a blood clot.

The marrow center of long bones such as limb bones contain yellow marrow,

which consists mainly of fat cells. Yellow marrow is capable of transforming itself

into red marrow to create red blood cells when needed.

Bone serves as the reservoir for 99 percent of the body's total calcium, an essential

nutrient for bone health as well as for heart, muscle and nerve function and clot

formation. In the form of calcium phosphate, calcium makes up the hard material of

teeth and bones. Bones also contain other essential minerals such as phosphorus

and sodium.

Osteoblasts, Osteoclasts and Osteocytes

There are three types of cells in mature bone tissue: osteoblasts, osteocytes, and

osteoclasts. Osteoblasts and osteocytes (osteocytes are osteoblasts that have

become encased in the bone matrix during bone tissue production) are found in the

surface of the bone and are involved in bone deposition, the process in which bone

tissue regenerates itself. Osteoclasts, on the other hand, are embedded deep in the

bone and are involved in the resorption, or break down, of bone tissue. The delicate

balance between bone deposition and resorption is what maintains bone mass,

density, and structure. One of the most important factors in their continued function is

the presence of calcium.

1. Osteoblasts - these are bone forming cells. They form an epithelium on the

outside of the bone, on the inside of the marrow cavity and on the inner surface of

cavities that are being made into bone. These cells have two main functions: a) to

synthesize, secrete and lay down an organic bone matrix consisting of collagen I plus

a few other bone-specific proteins which is laid down in a set parallel pattern b) to

facilitate the deposition of mineral on the organic matrix to harden it. This

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facilitation is brought about by ion pumping across the osteoblast epithelium to

concentrate the ions that will form the mineral.

2. Osteocytes - these are bone maintaining cells. Osteoblasts turn into

osteocytes after they are trapped in the matrix they have secreted. Once trapped,

they live in little hollows called lacunae that are seen in concentric rings or layers

within the bone matrix.

Neighbouring osteocytes are connected by cell processes that run through tiny

tunnels called canaliculli. The canuliculli connect neighbouring lacunae and the cell

processes running through them move nutrients and waste that the osteocytes need

or produce.

Osteocytes are no longer making matrix so they are metabolically less active and

have less RER and Golgi than osteoblasts.

3. Osteoclasts - these are bone matrix dissolving cells. Bone is continually

undergoing remodeling and repair even in adults. To remove old bone matrix prior to

remodeling, osteoclasts must convert and secrete chemicals such as acid and

enzymes such as collagenase to dissolve the matrix. Similar cells that dissolve

cartilage matrix are referred to as chondroclasts. Both of these cell types are

specialized macrophages that can phagocytose pieces of bone matrix as well as

dissolve matrix.

Bone Growth

Bone is living tissue that houses rich blood and mineral supplies and serves a

number of vital functions, including the control of its own growth and regeneration.

Bone development begins during the fifth or sixth week of pregnancy, when bones

take the form of a rubbery tissue called cartilage. By the seventh or eighth week of

pregnancy, cartilage is replaced by hard bone, in a process called ossification. At

birth, many bones still consist mainly of cartilage, and will ossify later - the process is

not complete until early adult life.

Bone surface is covered with a thin membrane called periosteum, which contains a

network of blood vessels and nerves. When you hit your elbow against the wall, the

pain you feel comes from the nerves in the periosteum. Beneath the periosteum is a

hard, dense shell of compact bone (compact bone is found in the body's long bones,

including most of the limb bones, such as the femur bone). It is within this compact

bone that a number of crucial functions take place.

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Within compact bone are groups of concentric circles, closely clustered together.

Each group of circles is called a Haversian system that resembles a cross-section of

a tree trunk. At the center of the Haversian system lie Haversian canals, or pipelines

that contain blood vessels, lymph and nerves, and carry essential nutrients like the

protein collagen that help nourish, grow and repair bones.

How Bones Are Built and Maintained

In one of its most central roles, bone stores and regulates the body's supply of the

mineral calcium. The body's most abundant mineral, calcium is essential for cell

function, muscle contraction, transmission of nerve impulses and blood clotting. In

the form of calcium phosphate, calcium makes up the hard outer coating of bones

and teeth.

The inside of our bones are rich operation centers. Beneath a hard surface layer lies

a layer of compact bone containing groups of concentric circles, not unlike the rings

of a tree. Each group of circles is called a Haversian system. Within these

Haversian systems are cavities called lacunae that contain the osteoblasts and

osteoclasts. It is the interaction of these cells that controls the calcium delivery so

essential for bone formation, nourishment, growth, and regeneration.

Command Central - How Calcium is delivered to Bones and Bloodstream

Calcium is initially delivered into the bloodstream according to the instructions of

parathyroid hormone, produced by the parathyroid glands in the neck; and calcitonin,

produced by the pituitary gland at the base of the brain. Osteoblast and osteoclast

cells take it from there, using calcium to conduct a constant state of remodeling

wherein old bone is removed and new bone is laid down. When bone becomes worn

or fatigued, osteoclasts break down and reabsorb the old bone tissue. This process

paves the way for the deposit of fresh, new bone cells, and also causes calcium salts

to be released into the bloodstream, thus building up the blood's calcium supply.

When the blood's calcium supply is high, osteoblasts take calcium stores from the

blood and deposit them on the protein framework of the bone, creating strong bone

tissue (and at the same time reducing the blood's level of calcium). This process

explains why, when there is not enough calcium in the bloodstream, the body will

take what it needs from our bones.

The success of this remarkable feedback loop depends on a number of factors, most

significantly the amount of calcium readily available in our bodies. While bones may

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be cleverly engineered to regulate and use calcium, there is not an unlimited calcium

supply.

Regulation of Blood Calcium and Phosphate Levels

1. Levels of blood calcium and phosphate are important not only for bone formation

but are even more important for proper function of nerves and muscles. For example,

if blood calcium is too low, many parts of the nervous system will become

hyperexcitable, leading to twitches and muscle tetany and cardiac fibrulation. Since

bones contain 99% of the bodies calcium and phosphate control of blood calcium

should logically involve regulation of how these elements are partitioned between

bone and blood.

2. Blood levels of calcium are usually about 2-3mmol/L. There are important

negative feedback loops designed to maintain blood calcium levels constant. These

loops involve the hormones calcitonin and parathyroid hormone. If blood levels of

calcium are too low, parathyroid hormone is secreted by the parathyroid gland and

travels via the blood to bones. Increased parathyroid hormone in the bone stimulates

osteoclasts to digest bone matrix thereby releasing trapped calcium into the blood to

restore its level to normal.

3. If blood levels of calcium are too high, calcitonin is released from the thyroid gland.

This hormone travels via the blood stream to bone and stimulates osteoblasts to

increase mineralization of the bone matrix. In this way, levels of calcium in the

blood are lowered by calcium being trapped in the bone matrix.

The Importance of Calcium Balance

Inadequate calcium stores in our bloodstream can leave bones vulnerable to

softening, deformity, fractures, and osteoporosis. More rarely, too much calcium

in the blood (hypercalcaemia) can cause such symptoms as muscle weakness,

heart conditions, and calcium stones in the urinary tract (kidney stones) which can

in turn impair kidney function and interfere with iron absorption.

In the younger years, 75 percent of the calcium consumed is naturally absorbed into

the bones, where it is employed to build and maintain bone density. Adequate

calcium absorption at this stage will fortify young bones that are growing rapidly and

also will have lasting benefits much later in life; if enough calcium is absorbed early in

life, the body will reserve these stores for later, when bone loss occurs more rapidly.

Peak bone mass is reached, after which time, it begins to drop. From this point on,

calcium is used to maintain (but not build) bone strength. Bone density continues to

decline with age.

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Bone Matrix

1. Organic Matrix - about 50% of the bone matrix is protein, mainly collagen type I,

and is laid down by osteoblasts.

2. Mineral Matrix - the other 50% of the bone matrix consists of the mineral

Hydroxyapatite. This mineral is crystalline and contains calcium, phosphorus and

hydroxyl groups. Mineralization is promoted by:-

a) nucleation of crystals by the collagen matrix

b) the pumping of ions across the osteoblast epithelium.

Thus, the job of the osteoblast is to pump calcium and phosphate ions into the matrix

space and pump hydrogen ions out of the matrix space, thereby concentrating the

ions needed to make hydroxyapatite.

Structure of Long Bones.

Diaphysis – the shaft is made up of compact bone. This contains a

central (Haversian) canal along the length of the bone. Nerves, blood

vessels and lymph vessels run through the periosteum via perforating

canals to connect to this central canal.

Epiphysis – proximal and distal epiphyses are made up of spongy

bone and contain red marrow.

Metaphysis – region where diaphysis joins epiphysis. This area

contains the growth plate.

Articular cartilage – hyaline cartilage covering epiphysis.

Periosteum – Membrane covering the bone except in region of

articular cartilage.

Medullary – The marrow cavity in the Diaphysis containing yellow

marrow in the adult bone.

Endosteum – membrane bone containing osteoprogenitor cells, this

lines the medullary.

1. The shaft or diaphysis consists of layers of compact bone surrounding a central

cavity filled with bone marrow, a site of blood cell production.

2. The outer surface of the bone is lined with periosteum, a connective tissue layer

that is protective, and contains both a blood vessel and nerve supply.

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3. The interior of the compact bone in the shaft is organized into cylindrical units

called a Haversian system. Each Haversian system contains concentric layers of

bone matrix and a Haversian canal at the center of the cylinder. Haversian canals

serve as conduits for blood vessels and run along the axis of the bone shaft. The

Haversian canals are connected to Volksmans Canals which fan out radially and

serve to bring in blood vessels from the surface of the bone. Thus, bone, unlike

cartilage, maintains a blood supply.

4. Haversian systems are built from the outside inward. First a hollow cylinder is

formed by osteoclasts eating away at the old matrix. Second, a layer of osteoblasts

form an epithelium on the inner surface of the cylinder and lay down and mineralize a

layer of bone. As they do so they become entrapped in the matrix and become

osteocytes. Next, a second layer of osteoblasts lines the new inner surface of

the cylinder and lay down another concentric matrix layer inside the first. This

cycle is repeated until only a narrow canal is left at the center of the cylinder - a

Haversian canal through which blood vessels and nerves run. Each matrix layer

is laid in a spiral manner with neighbouring layers spiralling in opposite

directions. This produces an extremely strong structure that can bear a lot of weight.

5. Matrix layers are also deposited on the inner and outer surfaces of the bone shaft

and Haversian systems are not present in these regions.

6. The epiphyses (ends) of long bones are composed of spongy bone and do not

have Haversian systems. Spongy bone consists of a reticular network of bone

matrix that looks a lot like a sponge after the cells are removed. The surfaces of

these ends are covered with hyaline cartilage on the articulating surfaces, that is,

those surfaces that are in contact with other bones at a joint. The cartilage

helps reduce friction and tissue wear.

7. A bone producing region referred to as the growth plate is found between the

shaft and each epiphysis. These regions are assembly lines for new bone matrix

which serves to lengthen the bone.

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Bone Development

Overview. Long bones and some other bones originate before birth as cartilage

models. These models are then turned into bone by a sequence of steps. Not all

areas of the bone are made simultaneously. The bone in the shaft forms first, and the

bone at the epiphyses second. Bone production continues throughout adolescence at

the growth plates and on the bone surfaces.

Sequence of Steps in Bone Development

1. Formation of Cartilage Models in the Foetus. Cartilage forms by appositional

growth (growth from the outside). Chondroblasts secrete matrix containing collagen

type II and then become trapped in the matrix.

2. Several layers of compact bone matrix are laid down by osteoblasts on the surface

of the shaft. These layers reduce the diffusion of gasses and nutrients into the

cartilage model and as a result the cartilage cells (chondrocytes) in the shaft begin to

die.

3. Osteoclast and chondroclast drill tunnels into the shaft thereby allowing the entry

of blood vessel forming cells, nerve endings, and osteoclasts and osteoblasts which

will serve to remodel the deteriorating cartilage inside into new bone.

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4. Osteoclasts hollow out cylinders inside the shaft while osteoblasts form new

Haversian systems that run up and down the shaft. This site of bone-forming activity

is referred to as the primary ossification center.

5. Osteoclasts now drill tunnels into the epiphyses. Again blood-forming cells, nerve

cells and osteoblast enter and start forming new bone. This site is now referred to as

the secondary ossification center.

6. By the time the baby is born, all long bones have been formed and have

mineralized, except for the growth (epiphyseal) plates that lie between the shaft and

each epiphysis. This plate will remain unmineralised throughout childhood so as to

provide a site for bone lengthening.

The Epiphyseal Growth Plate

Overview. The epiphyseal growth plate is an assembly line for formation of new

bone in the shaft thereby making the shaft longer as the youngster grows. By looking

at an assembly line we can tell in what order the product is put together. In the case

of the growth plate, there are seven distinct assembly steps mediated by seven

distinct regions in the growth plate. As a result what is formed as cartilage on the

epiphyseal side of the plate will be turned into bone by the time it reaches the

diaphyseal (shaft) side of the plate. In reality the matrix does not move at it is worked

on but rather the regions of the plate move as the matrix matures.

The Regions and Assembly Steps in the Epiphyseal Growth Plate.

These steps/regions will be described from the epiphyseal side to the diaphyseal

(shaft) side.

1. Growth Zone. First hyaline cartilage is formed. Next, the cartilage is expanded by

the

chondrocytes dividing. Each chondrocytes divides several times to form a column of

cells. These cells enlarge and secrete more cartilage matrix.

2. Transformation Zone. The cartilage matrix becomes mineralised. Diffusion of

nutrients and gasses stops and the cartilage cells die. The old cartilage matrix is then

dissolved and phagocytosed by osteo/chondroclasts.

3. Osteogenic Zone. Osteoblasts lay down new bone largely in the form of

Haversian systems.

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FRACTURES

As living tissue, bones are constantly regenerating, forming new bone cells when old

cells die off, or when disease or injury strikes. The soft marrow inside bone produces

red and white blood cells and clot-forming platelets, as well as a host of minerals,

most notably, calcium, which is responsible for bone's hardness. On the outside,

bone is composed of an interwoven fabric of proteins, minerals including calcium and

phosphorus, and tough collagen fibers, rendering it one of the strongest materials in

nature, able to bear large amounts of weight.

As part of the skeleton's flexible framework, our bones help to maintain the body's

form, enable us to move, provide a base for attaching muscles, and assist in their

flexing and pulling. Bones also act as a protective arm or to shield the body's vital

organs. Because our bones play so many vital roles, a broken bone or fracture,

depending on its nature and severity, may impact more than just the bone itself.

Types of Fractures and How They Affect Surrounding Tissue

There are two main types of fractures: In a closed or simple fracture, the broken bone

remains beneath the skin and the surrounding tissue is not damaged. In an open or

compound fracture, one or both ends of the bone may protrude through the skin,

creating a risk of infection to both the skin and the bone itself. If the bone has moved

out of alignment, the fracture is displaced.

Bones are usually broken directly across their width, but can also break lengthwise,

obliquely, or spirally. If the bone's breaking point has been exceeded only slightly,

then the bone may crack rather than break all the way through. This is sometimes

called a greenstick fracture. A fracture that entirely severs a bone is called a

transverse fracture. In the case of extreme force bone may actually shatter, a

condition known as a comminuted fracture.

When bones are fractured, they may expose internal organs to injury as well;

injured vertebrae can harm the delicate spinal cord; a broken rib can damage chest

organs such as the heart or lungs. A bone fracture is a break in a bone. The

surrounding tissues are usually injured as well.

Bone fractures are also classified by the position of the bone fragments, as follows:

comminuted, in which the bone breaks into small pieces

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impacted in which one bone fragment is forced into another

angulated, in which fragments lie at an angle to each other

displaced, in which the fragments separate and are deformed

nondisplaced, in which the 2 sections of bone keep their normal

alignment

overriding, in which fragments overlap and the total length of the

bone is shortened

segmental, in which fractures occur in 2 nearby areas with an isolated

central segment

avulsed, in which fragments are pulled from their normal positions by

muscles or ligaments

What are the signs and symptoms of the injury?

Signs and symptoms of a bone fracture include:

Pain that is usually severe and gets worse with time and movement

Swelling

Bruising

A limb or joint that is visibly out of place

Limitation of movement or inability to bear weight

Numbness and tingling

What are the causes and risks of the injury?

A bone fracture occurs when the force against a bone is greater than the strength of

the bone. Most fractures result from an injury.

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Basic Fracture Healing

.

Repair and Remodeling of Bone

1. Compression and decompression of bone regulates formation of new bone matrix. As a result new

bone matrix is added where stresses are greatest, thereby attaining increased ability to withstand

stress and avoid breaks. New bone matrix can be added either by remodeling of Haversian systems or

by appositional growth.

2. Repair of bone fractures occurs in four steps:

a) Hematoma and swelling of surrounding connective tissues immobilises the bone. This immobilisation

is markedly improved by medical application of a cast.

b) mending of bone by formation of fibrocartilage.

c) fibrocartilage callus is remodelled into spongy bone, and

d) spongy bone is remodeled into Haversian systems and appositional bone growth.

Treating fractures

PEMF settings base 50Hz and C can start after the acute inflammation is settled. In a closed fracture

you generally do not want to stop the formation of the haematoma, as this is essential to repair. However

if it is your vets wish to control the inflammation, PEMF can be used in the inflammatory stage at settings

base 50Hz and pulse 5Hz. PEMF at settings base 50Hz and C should be applied in sessions of at least

10 minutes but longer if possible, every four hours or at least twice a day until mobilisation. After

mobilisation this can be reduced to once a day until the fracture is healed. For non-union fractures,

treatment should be applied as above until the fracture shows signs of uniting then once a day until

healed. Initially, when applied to a fracture the bone may ache. If the animal shows signs of discomfort,

reduce the pulse settings accordingly and gradually increase as the animal becomes more comfortable.

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Initially, when applied to a non-union fracture, the symptoms may worsen, as in order to kick-start the

healing process the fracture will need to return to acute.

Treatment of an open fracture is essentially the same as above, but will often require surgery first. The

wound may also need to be treated with phototherapy. Care must be taken, as if vasodilation is induced

to early it could cause the wound to bleed.

Treat soft tissue damage accordingly. An exercise plan for the rehabilitation of the animal should be

implemented.

PEMF will penetrate bandaging and casts. The exact application of bandages and casts is beyond the

scope of these notes; further reading is advised if you are interested in bandage techniques.

SECTION 2 JOINTS

Connective tissue – General structure

Connective tissue varies depending on its specific function. However the basic components of

connective tissue are standard for each connective tissue type and vary only in their number. Individual

cells are loosely scattered and are surrounded by a mixture of chemicals called ground substance, or

extracellular matrix. There are several different kinds of cells; the most numerous cells are fibroblasts,

which secrete a mixture of protein molecules and polysaccharides. The most abundant proteins are

collagens, while the polysaccharides belong to the glycosaminoglycan group. Together, the molecules of

these molecules form a linked network that gives the matrix a gel-like consistency; but allows the

diffusion of dissolved gases, nutrients, hormones, and other required soluble chemicals. Collagen

fibres, Reticular fibres and elastic fibres are embedded in the matrix and improve its physical properties

both in strength and support. The remaining cells include fixed or wandering phagocytic macrophages,

which attack invading micro-organisms; Mast cells, which release histamine during inflammation; White

Blood Cell; Plasma cells which are mature B-lymphocytes producing antibodies; a n d Adipocytes for

lipid storage. In addition there is Hyaluron a t e , a viscous substance that binds cells and lubricates

joints; and Chondroitin sulphate, a jelly-like substance that supports and adheres in cartilage, bone,

skin, and blood vessels;

Dermatan sulphate in skin, tendons, blood vessels, and heart valves; Keratin sulphate in bone, cartilage,

and cornea; and Adhesion proteins that stabilise cells.

Fibres

Elastic - thin branching network of elastin & fibrillin, stretches up to 150%, found in skin, blood vessels,

and lungs.

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J

Joint Anatomy

Reticular - thin, branched collagen coated with glycoprotein, support for blood vessels, fat deposits,

nerves, muscle fibers, basement membranes and organ structure – stroma.

Collagen - thick bundles of protein (25% of all protein), resistant to stretching yet flexible, found in

bone, cartilage, tendons, & ligaments.

Tendons

Skeletal muscle tendons are cords of dense regular collagenous fibres that attach muscle to bone.

Dense regular, arranged in order with collagen fibres tightly packed, orientated in the same direction and

extremely strong eg; Aponeuroses which are collagenous bands or ribbons that cover the surface of

muscle or assist in attaching the muscle to another structure. Skeletal muscle consists of very large

individual cells held together by loose connective tissue. These cells can be a foot long and each

cell contains many nuclei. Collagen fibres surround each cell and groups of cells eventually merge with

the tendon, which conducts t h e force of contraction. The Epimysium is a dense layer of collagen

fibres surrounding individual muscles. One end of the epimysium is interwoven with the tendon, which in

turn is interwoven with periosteal fibres attached to the bone. The Perimysium divides the interior of

the muscle into compartments; each compartment contains a bundle of individual muscle cells called

fasciculi. The Endomysium encircles individual muscle cells and ties adjacent cells together.

Because the perimysium and endomysium are interwoven, an individual cell contraction will exert a

force on the tendon.

Ligaments

A ligament is a tough band of white, fibrous, slightly elastic tissue. This is an essential part of the

skeletal joints; binding the bone ends together to prevent dislocation and excessive movement that

might cause breakage. Ligaments also support many internal organs; including the uterus, the

bladder, the liver, and the diaphragm. Ligaments are sometimes damaged by injury. A "torn" ligament

usually results from twisting stress. Minor sprains can be treated with physiotherapy, but if the ligament

is torn, the joint may need to be immobilised or require surgical repair. If a ligament is made up of

several thick bands of fibrous branches, it is called a "collateral ligament." The word "ligament" comes

from the Latin word, "ligamentum," meaning a band or tie.

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scaffolding for the body and joints allow articulation between these bones. Bones

cannot move by themselves so muscles are needed to pull bones towards each other

to provide movement. Muscles are attached to the bones of the body by tendon.

Ligaments connect bone to bone. Ligaments are tough straps of tissue, which keep

bones in place. Ligaments tendons and muscles along with the joint capsule provide

stability for the joints.

Muscle Physiology

Reproduced from Fundamentals of Anatomy and Physiology. Martini A

Firstly, let us go over how movement in the body occurs. Bones provide the

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Normal anatomy of a horses’ fetlock joint (a synovial joint)

Cartilage

The cartilage which covers the ends of the bones where they meet in a joint is

Hyaline cartilage, more commonly known as articular cartilage. Cartilage is 70%

water. Approximately 50% of the non-water part is made up of the protein collagen.

The remainder is made up of proteoglycans, the two most important of which are

hyaluronan (hyaluronic acid) and chondroitin sulphate.

The other type of cartilage is fibrocartilage. An example of this is the menisci in the

stifle joints. Articular cartilage has a limited ability to repair itself. When injured it

attempts to repair itself with fibrocartilage. Fibrocartilage is a poor replacement and

does not return the function of the joint to normal.

21

Joint capsule and synovial membrane

As its name suggests the joint capsule encapsulates the joint. It is made of a tough,

thick, fibrous tissue. The blood vessels, nerves and lymphatic vessels for the joint

are sited in the joint capsule. The joint capsule is lined with a synovial membrane.

The synovial membrane is perhaps the most important element of the joint but

unfortunately it is predisposed to damage due to its thin, delicate structure. The

synovial membrane produces the joint fluid and vital substances required for normal

joint function.

Joint fluid

Joint fluid is produced by the cells of the synovial membrane. It has three primary

functions;

Joint lubrication

Cartilage nutrition

Removal of waste products

Joint fluid in a healthy joint is a similar consistency to that of honey. The viscosity of

joint fluid, along with its other properties, is affected by inflammation. The

examination of joint fluid is a useful diagnostic tool when investigating joint

disease.

How does exercise affect joints?

Movement is essential for joint maintenance. However, too much hard exercise can

affect joints badly.

Great care must be taken in the rehabilitation of joints that have been immobilised for

a period of time. In this situation it is the physiotherapist’s job to ensure that the

weakened supporting tissues and bone are strengthened slowly and correctly, to

avoid further damage.

The effects of movement on a joint are:

To pump joint fluid in and out of cartilage delivering essential nutrients and

removing waste products.

To maintain strength in supporting tissues and bones.

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Too much high-intensity exercise can overstress a joint, increasing the risk of injury

to tissues. If too much stress is placed on a joint it appears that the ability for that

joint to repair itself is compromised. Through a series of changes the cartilage gets

thicker and stiffer and the cartilage surface breaks down. This is detrimental to the

joint.

Inflammation of a joint

The word ‘Arthritis’ means ‘inflammation of a joint’. Inflammation is the body’s initial

response to injury. The purpose of inflammation is to isolate and destroy damaged

tissue or a foreign body such as bacteria.

The basic stages of inflammation are:

Blood vessels dilate flooding the area with blood (in humans this is

characterised by red skin, this can not usually be seen in animals due to their

coat). This is why an injured area feels hot to the touch.

Local blood vessels become inflamed. This causes gaps in between the cells

in the vessel walls. Fluid and cells, mostly white blood cells, leak into the

inflamed area.

White blood cells release certain chemicals and enzymes to destroy the

inflamed joint tissue. Unfortunately these chemicals can also destroy normal

tissue.

This is the acute stage of inflammation. The aim is to control the inflammation so to

reduce further damage by these inflammatory chemicals and enzymes, to otherwise

healthy joint tissue. At this stage full repair is usually possible. Acute arthritis does

not always result in chronic arthritis. If the trauma was a direct result of a fall or a

bang and the joint has not been made unstable by serious damage to the supporting

tissues then, if treated correctly full repair can be achieved. Unfortunately acute

arthritis often goes undetected for too long and chronic arthritis is the result.

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The process of Arthritis

Initial Injury

Inflammation

(acute arthritis)

Un-noticed/untreated Successful treatment

DJD, osteoarthritis

(chronic arthritis)

Possible

repair

24

SECTION 3

ORTHOPAEDIC CONDITIONS

Conformation

Poor conformation is a major factor in the development of joint disease. Equine

and canine conformation are covered on practical days; further reading is advised to

familiarise yourself with conformational abnormalities and their significance.

Degenerative joint disease (osteoarthritis)

DJD or Osteoarthritis is a result of chronic uncontrolled inflammation. This is a

common cause of lameness and manifests itself as many conditions.

Many things can stress a joint, some of which are listed below:

Direct trauma ie; kick or bang.

Joint fracture or fracture of the surrounding bone.

Injury or fatigue to the supporting tissues resulting in luxation or subluxation.

Poor conformation (equine and canine)

Poor hoof balance (equine only)

Poor exercise regime

Poor nutrition

Repetitive hard use

Infection

Ultimately, long-term inflammation within a joint leads to progressive and

permanent loss of articular cartilage and changes in the bone, joint capsule and

synovial membrane.

All the components of a joint are interrelated. Once chronic arthritis is underway, it

will usually attack all components of the joint. Sadly, with the exception of bone,

none of these components will repair well enough to return to their normal function.

Hence the condition is degenerative. In the presence of chronic inflammation, the

following changes will usually occur:

The area of insertion onto bone of the joint capsule and supporting tendons,

ligaments will calcify.

The joint capsule will become thickened, swollen and very painful, this is

known as capsulitis.

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The synovial membrane will release inflammatory chemicals into the joint fluid

which attack the cartilage. Inflammation of the synovial membrane is

known as synovitis. The synovial membrane will try to heal itself but the

replacement tissue will not be as efficient and function will be impaired.

Excess joint fluid may be produced, increasing the pressure on the joint. This

causes pain. A decrease in joint fluid and therefore joint stiffness and pain

will usually follow.

Deterioration of the articular cartilage will occur exposing the subchondral

bone. Bone responds to inflammation by producing more bone. In a healthy

joint the smooth cartilage provides the bones with an almost frictionless

surface. In an osteoarthritic joint, the surfaces are hard and boney and do not

lend themselves to easy, pain free movement. When examining a joint with

DJD, new bone may be seen and felt as hard lumps around the joint.

The role of physiotherapy

It is important that you are familiar with the different stages of arthritis and the

changes that occur, so that you can give the appropriate treatment. The key with

arthritis is to catch it in the acute stage and resolve the underlying cause to prevent it

turning chronic. Unfortunately, it is not usually noticed until the animal is lame and

usually by this time chronic inflammation is underway and irreversible changes

have occurred. In the case of acute inflammation brought on by a direct injury rather

than a repetitive source such as bad conformation, you will usually be called out in

time to make a difference. The aims of treating acute arthritis are:

To reduce inflammation

To heal supporting tissues

To restore normal joint function and limit further damage.

PEMF at a base 50Hz and a pulse of 5Hz will cause vasoconstriction and reduce

inflammation. DO NOT use any modality that will cause vasodilation at the acute

stage as this will increase inflammation. Once the inflammation has subsided you

will need to work on the damaged supporting tissues. If these are left untreated, it is

likely that the joint will be unstable and further damage will occur. Treat muscles with

PEMF at base 50 Hz and pulse 17.5Hz, or with laser or ultrasound. To achieve

optimum results hire the owner a PEMF machine so that the animal can be treated

regularly. To treat damaged ligaments the optimum setting is base 50Hz pulse

25Hz or C (note: it is not advised to use this over chronic athritic joints, where bone

deposition would be

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a disadvantage). Any injury that may have occurred to the bone should also be

treated with PEMF at base 50Hz and pulse 25Hz or C. At this stage the cause of

injury should be addressed and steps should be taken to limit the chances of it

reoccurring.

Once DJD is established, nothing can be done to reverse the changes. The aim is to

improve quality of life and slow deterioration. Secondary problems can cause much

discomfort and if untreated can speed up the deterioration of the joint.

Surrounding muscles will have been compensating for the joint pain and adhesions

and spasm are likely to be present. This causes a further reduction of range of

movement (ROM) in the joint. A healthy level of exercise is essential to nourish the

joint and a joint that is not utilised to its capacity will deteriorate more quickly. PEMF

at base 50Hz and pulse 17.5, laser or ultrasound to increase vasodilation,

followed by massage and stretching will break down adhesions and restore some

joint function. Depending on the severity of the injury to the muscle and the level of

joint deterioration this may be a painful process. It may be necessary to apply

PEMF at base 200Hz and constant as this will limit the pain. Therapy should

continue on the muscle to help clear debris and swelling caused by the breaking

down of adhesions otherwise the muscles will be sore and the reduced ROM will

return. Gentle exercise should then be encouraged to help maintain ROM for longer.

Back and neck pain is common in animals with joint pain. Regular treatment of these

areas will increase comfort.

Hydrotherapy is useful to keep the animal fit and promotes a good range of

motion, but should not be the only form of exercise as weight bearing is essential

for joint function.

It should be noted that PEMF only works at an orthopaedic level at base 50Hz and

pulse 25 or constant. It will not affect bone at any other setting.

Developmental orthopaedic disease (DOD)

DOD is a group of juvenile developmental diseases of the locomotor system.

These conditions are limited to before the bones are fully grown. Certain DOD’s

can be hereditary, however poor nutrition and excessive exercise in the young

animal are considered to be contributing factors. Owners are often ignorant to the

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potential dangers of overfeeding a young animal which can result in DOD. There

are several sub-groups within DOD.

Osteochondrosis

Osteochondrosis (OCD) is one of the developmental problems grouped under the

general heading of Developmental Orthopaedic Disease (DOD) and is most

commonly first noticed in young horses and dogs from 6 months to 2 years old.

Osteochondrosis is recognised as the failure of cartilage to ossify to create bone.

The retained cartilage then starts to die off and, if stressed can break up. If the

disease progresses to this stage it is termed osteochondrosis dissecans. Fragments

of cartilage can remain loosely attached or break off completely when they are

then referred to as "joint mice". If the cartilage deteriorates and cracks in the

centre of the joint it can allow synovial fluid to enter, creating a bone cyst. These

problems can cause the animal considerable pain and often require surgical

treatment.

There are many reasons put forward as to why osteochondrosis occurs. Many

believe that a genetic predisposition exists. Various studies have identified individual

stallions that produce a significantly higher number of offspring with OCD although

they may show no signs of the disease themselves.

Nutrition is inextricably linked with growth and development so it is no surprise that

there are many ideas as to how the diet may induce developmental problems. High

protein diets have been attributed as the cause of many developmental problems but

this has not been proven in scientific studies. However, research has shown that

high-energy diets have resulted in an increased incidence of OCD, and it is known

that being overweight as a young animal also increases the risk.

The importance of a correct balance of minerals is increasingly being recognised as

necessary in trying to prevent developmental disorders. Too much or too little of a

particular mineral can be equally as catastrophic to bone and cartilage formation and

so it is important not to consider minerals in isolation as many can interact, affecting

their availability to the animal.

Canine DOD is covered in the canine specific module.

The role of physiotherapy

Treatment of these diseases is limited. Surgery has shown positive results. Great

28

care should be taken when treating animals before the growth plates have closed.

PEMF should not be used at an orthopaedic setting as this may disturb the natural

process. PEMF should not be used in DOD where ‘joint mice’ or bone deposition is a

problem. Physiotherapy can only really be applied to DOD to help aid the comfort of

the animal. Massage to help with compensatory pain will promote well being. As the

animal ages, physiotherapy can help to avoid or treat secondary problems

associated with DOD such as pressures on other joints, muscles, tendons and

ligaments due to resulting unusual conformation and gait. The physiotherapist can

assist in the rehabilitation of the animal after surgery.

Young horses may develop contracted tendons as they grow. These can be treated

with ultrasound. As always this should only be under the vets’ guidance.

COMMON EQUINE ORTHOPAEDIC CONDITIONS

Splints

The 2nd and 4th metacarpal and metatarsal bones are more commonly known as

splint bones. The 3rd or large metacarpal or metatarsal is more commonly known as

the cannon bone.

‘A splint’

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A splint i s a bony enlargement sited between a splint bone and the cannon bone.

This is usually found on the medial side of a forelimb but can be found at this point in

any limb. The splint bones are attached to the cannon bone by the interosseus

ligament. Disturbance to this ligament causes inflammation and therefore new bone.

Formation of a splint is painful and the horse will usually be lame, especially on a

hard surface. Once the splint has formed it causes no pain, providing there are no

complications. A splint will usually take 6 weeks to form.

Development of splints is often related to poor conformation or hoof balance. Horses

often develop splints during the process of being broken in (starting work). There

will usually be an underlying conformation fault and the added pressure of work

puts extra strain on the ligament. Splints are most common in horses from 3 to 6

years of age but can also be found in older animals. Splints can develop in young

horses where unnatural rapid growth has been induced by overfeeding. Direct

trauma such as a kick can cause the splint bone to fracture, the ligament to be

damaged and thus a splint will form.

Physiotherapy treatment

Once a splint is formed it is unlikely to cause any further problems. The main

concern for the owner is usually cosmetic, especially if the horse is a show animal. A

static magnetic pad applied to the splint with a little pressure has been shown to

elongate the splint and therefore reduce its apparent size. PEMF can be used to

reduce inflammation, however generally the splint will have initiated for a reason and

will ‘flare up’ again once the animal returns to work. Generally, the formation of a

splint will run its course and heal with no further problems. In some circumstances,

however the splint can keep re-inflaming and healing is prolonged. Occasionally

surgery is required, especially if the bony growth is interfering with surrounding

structures such as the suspensory ligament. Post-operative physiotherapy and

rehabilitation can be an advantage.

Navicular disease

The Navicular bone is the distal sesamoid bone in the horse’s foot. It l ies distally

from the middle phalanx, between the palmar/plantar aspect of the pedal bone and

the deep digital flexor tendon. The navicular bone acts as a fulcrum for the

DDFT, which passes over the navicular bone and attaches to the pedal bone.

Between the navicular bone and the DDFT is a bursa (a sac of synovial fluid

designed to reduce friction). During motion, the navicular bone serves to keep the

30

DDFT’s attachment to the pedal bone at the same angle, regardless of the relative

positioning of the middle phalanx. It is also an important part of the distal

suspensory apparatus, and supports the coffin joint against over-extension.

The hoof in its natural state and in the absence of conformation faults, works in a

balanced and effective manner. Once this is disturbed detrimental changes can

begin to take place. The navicular bone can become diseased. The DDFT and the

bursa can later be affected. The whole function of the hoof will be disturbed and the

bone will eventually become demineralised. Unfortunately the early changes that

occur can be hard to pick up with current diagnostic techniques (with the exception of

MRI) therefore it remains up to the eye of a good horseman to pick up tell-tale

signs. The initial signs of Navicular disease are:

A stilted, shuffling gate

Intermittent lameness, especially when turning

Changed performance, refusals, especially on hard ground.

Postural changes, toe pointing, sometimes leading to back problems.

It should be noted that these signs can also indicate other conditions, including

shoulder injuries. However, with the advent of MRI, it is now understood that many of

the conditions once considered to be ‘navicular disease’ have other causes, such as

problems with the DDFT within the hoof capsule, a torn manica flexoria, and

ligamentous injuries within the foot.

Treatment

In cases of Navicular or other foot related diseases, best results will be achieved

when the Vet, Physiotherapist and Farrier all work together. The aims are:

To support the heels and to relieve the pressure on the DDFT, bone and

bursa.

To increase blood flow to the hoof.

To restore normal hoof function as much as possible.

To return adapted gait to normal.

Physiotherapy treatment

PEMF on a setting of base 50Hz and pulse 17.5Hz, will increase vasodilation

and blood flow to the hoof, as will water wellies.

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Relieve associated muscle pain. Most muscle groups can be affected when a

horse is compensating for foot pain. Each animal is an individual and rely its

own area of strength to help the out. However there is usually, if not always,

shoulder stiffness. The gait will not return to normal if the horse has restricted

range of movement, even if the feet are more comfortable. Phototherapy,

massage and stretches will help free off the shoulder. In cases where the

pain and injury is more advanced, application of Ultrasound or PEMF at base

50Hz and pulse 17.5Hz may be required.

Static magnets in the form of overreach boots will help maintain the blood

flow to the hoof on a continual basis.

Pedal osteitis

‘Osteitis’ is inflammation of bone. Therefore the term ‘Pedal osteitis’ means

inflammation of the pedal bone (3rd phalanx). Debate about this condition is

ongoing. It seems the parameters of the condition remain undefined. Pain is

associated with pressure between the bone and the hoof capsule. Damage to the

pedal bone can occur due to;

concussion

compression

Stretch traumas from laminitis

Wounds to the sole

Fractures

Physiotherapy treatment

This condition should be treated much the same as Navicular disease, from a

physiotherapy aspect. Due to altered gait, blood supply and hoof function will have

been compromised. PEMF at a setting of Base 50Hz and a pulse of 17.5Hz can be

used to increase the blood supply to the hoof. Care must be taken not to use this

setting in the acute stages where there may be tearing of the corium and

inflammation. Water wellies can be used to increase blood flow to the hoof and static

magnets; in the form of overreach boots can be used on a continual basis. PEMF

can be used to help repair fractures on a setting of base 50Hz and pulse 25Hz or

32

constant. However great care must be taken not to use this setting where there is a

possibility of bone spur formation. Strictly follow the Vets’ guidance.

Ringbone

Ringbone is DJD of the pastern or coffin joint. Ringbone can be classified as high or

low:

High ringbone is when new bone growth is sited at the pastern joint.

Low ringbone is when the new bone growth is sited at the coffin joint.

Ringbone is sub-divided further into articular and non-articular;

Articular ringbone involves the joint and consequently is painful and interferes

with movement. The prognosis is poor.

Non-articular ringbone is the formation of bone in the supporting ligament,

which attaches outside of the joint capsule. Therefore the joint is not

involved. This is also known as non-arthritic ringbone. Once this has settled,

in the absence of further stress, the horse is likely to remain sound.

Physiotherapy Treatment

Treatment of compensatory muscle pain is the main role of physiotherapy with

ringbone. PEMF can help joint fusion and ossification if that is desired.

Sidebone

Sidebone is ossification of the collateral cartilages of the feet. This is thought to be

due to concussion or can be through direct trauma. Sidebone is less common that it

used to be. It was a common cause of lameness in Draught horses. It is more

commonly seen in horses with wide flat feet rather than in the thoroughbred. If

lameness is present it will usually be during the early stages. The horse will usually

be sound once the ossification is complete. When functioning normally these

cartilages are part of the shock absorbing mechanism of the distal limb. Once these

cartilages have ossified their shock absorbing quality is nullified. Massive formation

may cause ongoing lameness due to pressure on the internal structures of the hoof.

33

Physiotherapy treatment

PEMF at a setting base 50Hz and pulse 25Hz or constant may optimise the speed of

ossification thus enabling the horse to return to work sooner. It must be confirmed

that there are no unwanted boney changes happening within the hoof before this

treatment takes place. Treatment to compensatory muscle pain can be applied as

normal.

Bone spavins

Bone spavin is a common cause of lameness in the hock. It is thought that stresses

of poor conformation are the main factor in the development of bone spavin.

The hock is a complex structure. Refer to your anatomy texts and make sure you can identify the following;

The talus and trochlea

Individually the 6 tarsal bones

The tibiotarsal articulation

The tasometartarsal articulations

The intertarsal articulations A bone spavin is DJD of the hock. A bony enlargement forms on the inside of the

hock due to inflammation of the joints and ligaments in the area. The most

commonly affected joints are the distal intertarsal and the tarsometatarsal joints.

Ideally, the presence of a bone spavin will ultimately result fusion of the directly

related joints. As the joints involved provide very little movement this only has a

minor effect on movement and the horse will become sound.

Treatment

Joint fusion can be encouraged by continuing work on a pain killing drug (only under

veterinary instruction, you must never prescribe a drug) such as phenzylebutazone

(bute), or sometimes surgery is necessary. Many horses will have the affected joint or

joints medicated (for example with steroids to treat inflammation and hyaluronic acid

to promote normal lubrication) so they can continue to compete, which is not possible

when on bute treatment. In either case, fusion can be encouraged by PEMF at

settings of base 50Hz and pulse 25Hz or constant. It must be confirmed that there is

no further unwanted bone formation occurring within the joint before this treatment

can take place. Compensatory muscle pain can be treated as normal.

34

COMMON CANINE ORTHOPAEDIC CONDITIONS

Cruciate ligament rupture

There are two cruciate ligaments in the knee (stifle), which are cranial and caudal.

The cranial ligament as the name suggests is to the front of the knee and is the

most common ligament to suffer injury. Rupture of this ligament can lead to

instability of the joint and then further problems such as DJD. The caudal

ligament is rarely damaged.

Normal anatomy of a stifle (collateral ligament removed for illustration)

35

There are several types of cruciate ruptures.

A traumatic rupture – due to sudden injury such as catching a foot in a

rabbit hole.

A complete rupture – usually in middle aged dogs and can happen at any

time during normal exercise.

Partial ruptures – usually seen in young dogs

Arthritis associated rupture – in rare cases a cruciate rupture can be

secondary to inflammatory arthritis.

The cause of gradual degeneration of the cruiciate ligament, resulting in rupture, is

not yet known. Research in this area is ongoing. When ruptures occur, seemingly

for no reason, it is apparent that the ligament structure is altered such that it fails to

function as it should. Although this condition appears to be more common in large

breeds it is not known why this is. Cruciate rupture also appears to be more common

in overweight dogs. There are also investigations commencing on the genetic

relation to this disease.

Treatment

The primary treatment for this condition is surgery. There are several different

options available and individual Vets will favour a particular method. The general

name for the surgery is ‘cranial cruciate repair’. The surgical techniques can be

divided into intra-articular (inside the joint) where the ligament is replaced or extra-

articular where something is used outside the joint to replace the function of the

ligament. More information on surgical techniques and their specific issues is in your

canine module.

Unfortunately, because of the severe trauma to the joint, osteoarthritis will usually

occur. Often the ligament is deteriorating slowly, unnoticed, and by the time the

ligament ruptures, osteoarthritis is already present. Therefore physiotherapy

treatment should not stop once the dog has recovered from surgery, but continue at

regular intervals throughout his life to cope with the knock on effects of joint

deterioration.

36

Canine hip dysplasia (CHD)

Canine hip dysplasia is a disease of abnormal development of the hip joint. This

condition, although heritable, is undoubtedly affected by nutrition and weight

gain. CHD is defined by a laxity of the soft tissues supporting the joint, instability

of the joint and malformation of the femoral head and acetabulum and occurs

between birth and 6-9 months of age. Progressive osteoarthritis is often the long

term affect of CHD. Some dogs with hip dysplasia remain undiagnosed until

osteoarthritis develops in young adulthood, whereas other will be diagnosed as young

dogs due to abnormal movement patterns (typically a ‘bunny hopping’ gait) and/or

reluctance to exercise or tiring easily. Many breeds are predisposed to CHD, more

information is included in the canine module.

Treatment

Treatment may be surgical or medical, depending on the severity of the disease, the age of the dog, and their intended use. There are several procedures used, the most common of which are:

Triple pelvic osteotomy (TPO) – this procedure involves rotation of the

acetabulum to provide better coverage and stability of the femoral. This

procedure is only carried out in very immature dogs with no signs of

osteoarthritis.

Total Hip replacement (THR) – in severe cases of osteoarthritis the hip joint

can be totally replaced by an artificial device.

Femoral head and neck ostectomy (FHO) – this procedure involves the

complete removal of the femoral head and neck. The supporting tissues and

a pad of fibrous tissue are then required to support the joint. Although this

seems a drastic procedure, it is often very successful especially in smaller

37

dogs and dogs that are not overweight.

38

Legg-Calve- Perthes Disease

The cause of this disease is unknown. Legg-Calve-Perthes disease is avascular

necrosis and collapse of the femoral neck. Terrier breeds are predisposed to this

condition. Atrophy of the caudal thigh muscles is usual.

Treatment

Surgical treatment by FHO is most common. Rehabilitation is vital to prevent excess

fibrosis and restricted ROM.

Patella Luxation

Patella Luxation is a DOD. It is largely a disease of the small breeds particularly the

toy and minature breeds. This condition is congenital but in rare occasions can be

caused by trauma. Sudden onset of lameness can be caused by the patella ‘locking’

in a luxated position or by the exposure of sub-chondral bone as a result of

osteoarthritis. This disease causes the classic terrier gait of lifting the leg for several

steps while running. This is not a normal gait and does signify a disease process,

despite many owners ignoring the signs. Patella luxation is classified by its severity;

more severe cases may require surgical intervention to improve the clinical signs.

Treatment

The patella luxation can be surgically stabilised, and if this is done early enough (6 to

14 weeks of age) then osteoarthritis can be avoided. Sadly this condition is often left

until the dog is lame and by this time osteoarthritis has set in.

Elbow dysplasia

Elbow dysplasia is another DOD. It occurs most commonly in retriever breeds, although

can occur in any breed. There are many forms of elbow dysplasia affecting different

parts of the joint; more information on the different types is included in your canine

module. However, in most cases the animal has a history of intermittent forelimb

lameness as a young dog, and osteoarthritis is the inevitable result of untreated elbow

dysplasia. Various surgeries can be performed to correct the abnormalities and joint

mice associated with elbow dysplasia. Treatment of post-operative elbow joints is the

same as for other post-operative conditions, and treatment of the secondary arthritis

that may develop from elbow dysplasia is the same as for other arthritic conditions.

Physiotherapy Treatment

Example rehabilitation plans will be included in a later module.

39

Luxations

Luxations are also common in other areas such as the hip, elbow, carpus, tarsus,

and phalanges in dogs and often occur at the same time as a fracture. Subluxation

can also occur, in these cases some function may remain as the bones only partially

separate.

The aims for the treatment of the osteoarthritic joint are consistent. Maintenance of

limb ROM and strength in the supporting tissues is the long term aim.

Physiotherapy after surgery is vital. The short and long term aims are similar after all

types of surgery involving joints. The physiotherapist should always follow the vets’

guidance when formulating a rehabilitation plan.

Short-term aims:

Swelling and inflammation control – during acute inflammation

(approximately 72 hours after surgery) PEMF at settings base 50Hz and

pulse 5Hz or cryotherapy for vasoconstriction. After acute inflammation has

subsided PEMF at settings base 50Hz and pulse 17.5Hz or ultrasound to

increase vaso-dilation and toxin removal.

Reduce chance of infection and aid healing of incision – Prompt

application of blue light phototherapy to the incision, twice a day. After acute

inflammation has settled, visible red and infrared phototherapy to the incision

to aid healing. Blue light phototherapy can be continued if necessary.

Improving joint ROM – passive ROM exercises. These should start as soon

as possible after surgery, if possible when the animal is still anaesthetised,

and continue 2 to 3 times daily.

Limiting muscle atrophy – Muscle atrophy will occur very quickly in

surrounding tissues. Electrostimulation can be applied as early as the day

after surgery. However care must be taken not to make the muscles sore.

The animal will be on a pain controlling drug, therefore his reaction to the

discomfort felt with muscle fatigue will be absent or delayed. Therefore there

is a risk of over exercising the muscles. The effects of muscle fatigue will be

counterproductive in the rehabilitation of the animal. Use guidance from the

vet as to when to start electrostimulation. Further muscle atrophy can be

40

reduced by increasing blood flow to the muscle and with the use of ROM

exercises.

Pain control – The vet will have addressed pain control in the animals

medication. PEMF on settings base 200Hz and C will deliver maximum pain

relief. Apply before mobilisation, massage, ROM exercises and muscle

stimulation.

Limit formation of adhesions and scar tissue – mobilisation and massage

of surrounding soft tissues as soon as possible after surgery, up 2 to 3 times

a day.

Long-term aims:

Return ROM to normal – Rehabilitation plan, gradually increasing use of the

limb and continued ROM exercises.

Return weight bearing to normal – Same as above. Rehabilitation plan

must include exercises to promote weight bearing.

Maintain strength in supporting tissues – Continue electrostimulation for

as long as necessary. Rehabilitation plan must include exercises to maintain

muscle strength and tone.

Slow the deterioration of the joint – A gradual rehabilitation plan, followed

by advice on maintenance and regular visits. Regular visits should include,

treatment to supporting muscles and mobilisation to help to nourish the joint.

Pre-operative physiotherapy

The animal can also benefit from pre-operative physiotherapy. If the animal will be

required to swim after surgery and has not had experience of hydrotherapy pools it is

a good idea to introduce him to this before surgery. If he is accustomed to the pool

before surgery then postoperative swimming will be less stressful for him and

therefore reducing the chance of re-injury.

Treatment of muscle atrophy before surgery can be beneficial in the recovery of the

animal.

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SECTION 4

ADDITIONAL INFORMATION

SYNOVIAL ENLARGEMENTS

Synovial fluid is found in joint cavities, bursae and tendon sheaths. In times of stress

the synovial membrane can secrete excess fluid causing distention of the capsule or

sheath. Treatment of tendinous swellings and bursae will be covered in a later

module.

Trauma to a joint can affect the production of synovial fluid. With an increase of

synovial fluid the joint will become distended. This will often leave a permanent

enlargement, in the hock of a horse this is known as a bog spavin. This must not be

confused with a bone spavin. A bog spavin rarely makes a horse lame but can in

some cases be indicative of further changes.

Treatment

In the absence of lameness, treatment of synovial swellings is usually only necessary

in an attempt to reduce the unsightly blemish. Draining and anti-inflammatory

injections or drugs are a treatment which can reduce the swelling, although they are

seldom successful in the long term.

Physiotherapy treatment

If the Vet wants to reduce inflammation PEMF settings base 50Hz and pulse 5Hz

should be used. Pressure can be applied over cosmetic blemishes to reduce their

size (for a period of time).

ORTHOTICS

Orthotics is defined as the use of a device to improve or restore function. An

Orthosis is a device such as a splint or brace that supports weak or ineffective joints

or muscles. These can be used after surgery to immobilise the affect part of the

body. A splint or a brace can also be used to help support limbs weakened by

conditions such as neurological problems or muscle atrophy. With a little adaptation

these devices can also be used to increase proprioception and weight bearing.

SURGICAL TECHNIQUES

There are many options open to Orthopaedic surgeons with regard to the surgery

they choose. Individual surgeons will have their preferences. Surgery on horses is

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more limited than on small animals due to the nature of the beast. Serious fractures

in horses will often lead to euthanasia. Small animals make better patients, therefore

euthanasia can often be avoided.

Arthrodesis is a surgical fixation of the joint causing the joint surfaces to fuse. This

surgery is often the choice where DJD is present in the carpus and tarsus. Internal

fixators such as pins, screws and plates and external fixators are used to treat

fractures.

Arthroscopy involves the insertion of a fibreoptic rigid tube into the joint cavities.

This procedure is investigative but damaged tissue and debris can be removed and

samples can be taken. Arthroscopic surgery is less invasive than conventional

surgery, resulting in a more swift recovery. Scar tissue formation is kept to a

minimum.

SLINGS AND CARTS

Slings and carts can be used in the rehabilitation of small animals. These will be

covered in a later module.

PREVENTION

A vital part of physiotherapy is prevention. Although it is not the physiotherapists’ job

to diagnose a condition, recognising signs can be invaluable. You must be careful

not to overstep the mark but, suggesting to an owner to talk to their vet about their

dogs weight or to talk to their farrier about the possibility of different shoes, can be

done in a way not to offend anyone. It is important that all veterinary

paraprofessionals work together and not against each other! Equally if you notice a

horse has particularly upright shoulders or a little dog spends all his time looking up

at his owner, then to suggest extra treatment to those areas affected to prevent

problems in the future is very good practice.

There is a fine balance between keeping an eye out for potential problems and over

analysing. Care must be taken not to scare owners. Gently advise them if you think

it would be beneficial. Some people don’t take criticism of their animals very well;

care must be taken in pointing out conformation faults so as not to offend the owner.

In short, keep an eye out for potential problems, be diplomatic and don’t overanalyse!

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EVALUATION

The body is like a finely tuned machine. In health all the cogs of the machine work

together. If one of the cogs is broken and this is not identified the other cogs take on

the work of that cog so that outwardly no malfunction can be seen. The other cogs

gradually develop signs of wear and tear and fatigue until eventually the machine is

beyond repair. The role of Physiotherapy in the treatment of Orthopaedics is not only

to help repair bone and improve mobility of joints. Very often we are presented with

the secondary problems (the symptoms) and the initial problem (the cause) could

easily be progressing, undetected. A good physiotherapist will always address the

overall picture, so as to limit the effect of problems to one cog on another!

The range of orthopaedic conditions which can develop in animals is far too

extensive to be covered in this module. You are not expected to know all the

conditions thoroughly, you are not training to be a Vet! However an

understanding of the condition you are treating is essential so that you can provide

the correct treatment. When you receive a Vets’ referral, if you don’t understand

the diagnosis, look it up before you go to treat the animal. If you don’t fully

understand the diagnosis ask the vet ‘what effects do we want to achieve’. If he says

‘reduce inflammation’ or ‘fuse the joint’ you can apply the relevant treatment. Always

keep the Vet informed and most importantly, always, always follow the treating Vets’

advice.

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APPENDIX

TERMINOLOGY

Arthrocentesis – Incision into a joint

Ankylosis – Abnormal immobility and consolidation of a joint

Arthrodesis – The surgical fixation of a joint by fusion of the joint surfaces.

Arthrosis - Degenerative disease of a joint.

Articulation – a joint

Callus – The boney material that bridges fractured bone fragments

Crepitus – Boney crepitus, the crackling sound produced by the rubbing together of

fragments of fractured bone. Joint crepitus, the grating sensation caused by the

rubbing together of dry synovial surfaces of a joint.

Dysplasia – Abnormality of development

Fibrillation – A fibrillar, striated pattern seen on cartilage undergoing early

degenerative change

Flaccid – Weak, lax, soft

Hematoma – A soft tissue swelling filled with blood

Non-union – Failure of the ends of a fractured bone to unite

Osteoarthritis – Chronic inflammation of a joint

Osteoporosis – Atrophy of bone

Periosteum – The tough fibrous membrane surrounding bone

Synovial fluid – The fluid in joint cavities, bursae and tendon sheaths

Spondylitis – Inflammation of one or more vertebrae