Tendons, Ligaments, And Bones

Front 1

• How can you get tendonitis?

Back 1

o Overuse – repeated motion which can lead to ischemia

Front 2

• Overuse can lead to what?

Back 2

o Stimulates fibroblasts, then get thicker tissues, and the fibroblasts stimulate the fibroblast activated growth factors and myofibroblasts
o Can also lead to limited motion and pain

Front 3

• What do you want to do if you have overuse of tendons?

Back 3

o Rest for 2 days, ice, compression, stretching (low load) by PROM or AROM by isometrics to end of toe region

Front 4

• What is the function of tendons?

Back 4

o Connect skeletal muscles to bones

Front 5

• What are tendons composed of?

Back 5

o DCT
o Regularly arranged parallel bundles of collagen fibers
o Mainly Type I collagen with small amount of elastin and other types of collagen fibers

Front 6

• What is the site of tendon connection to muscles and bones?

Back 6

o Myotendinous and osseotendinous junction respectively

Front 7

• How are the collagen fibers in tendons arranged?

Back 7

o In a regular, but multidirectional fashion so they can withstand forces in all sorts of directions

Front 8

• What is the outer layer of the tendon covered by?

Back 8

o A layer of CT called paratenon

Front 9

• What are collagen bundles within a tendon bound together by?

Back 9

o Epitenon sheets

Front 10

• What are collagen fibers within the bundles bound together by?

Back 10

o Endotenon sheets

Front 11

• What is important about the endotenons?

Back 11

o Blood vessels and nerve fibers are distributed within the tendon here

Front 12

• What is a bursa?

Back 12

o Hard outer covering with jelly-like substance in it

Front 13

• What are long tendons usually covered by?

Back 13

o A fibrous sheet called retinacula

Front 14

• What facilitates tendon gliding over the nearby structures?

Back 14

o The synovial layer inside the retinacula

Front 15

• What protects the tendons when gliding over the bony pulleys?

Back 15

o Thickening of the retinacula

Front 16

• What protects tendon structure and facilitates the movement over the hard bony areas?

Back 16

o Bursa

Front 17

• What kinds are forces are tendons subject to?

Back 17

o Stretching force
o Compressive force

Front 18

• Tissue structure of tendons that are subject to stretching forces are different from what?

Back 18

o Structure of tendons that are subject to both stretching and compression

Front 19

• What does the arrangement of collagen fibers help with?

Back 19

o Dissipating compressive forces symmetrically to other areas

Front 20

• How much can tendons stretch without being denatured?

Back 20

o Up to 4% of original length

Front 21

• Stress levels up to what would rupture collagen fibers in the tendon?

Back 21

o 8-13%

Front 22

• Because tendons function to transmit forces, they resist what?

Back 22

o Lengthening under stress

Front 23

• Increased load on the tendons would do what?

Back 23

o Stimulate fibroblasts
o Initiate collagen production in the tendons

Front 24

• What would immobilization and decreased stretching cause in the tendon?

Back 24

o Rapid decrease in collagen production
o Decrease in tendon cross section
o Decrease in strength for resisting mechanical stresses

Front 25

• Considering tendon response to mechanical loading, how would casting and prolonged joint immobilization affect tendon strength and structural integrity?

Back 25

o If you have an immobilization, you have to activate CT by stretching it in the line of action
o If needed to compress CT, this is because you want it thinner; for example in a burn

Front 26

• Why would you need to have granulation?

Back 26

o To have capillary budding to provide nutrients

Front 27

• How could structural changes with immobility be reduced or prevented?

Back 27

o Mobilization

Front 28

• Are tendon structural changes irreversible?

Back 28

o No, they are reversible

Front 29

• Any loss of tendon cross section and consequently its strength can be improved how?

Back 29

o With proper loading during or after an immobilization period

Front 30

• Name the five stages in healing

Back 30

o Inflammatory (0-5 days)
o Proliferative (day 5-week 6)
o Early remodeling (week 6-8)
o Middle remodeling (weeks 8-12)
o Late remodeling (week 12-final healing)

Front 31

• How long does the inflammatory healing stage take?

Back 31

o 0-5 days

Front 32

• How long does the proliterative healing stage take?

Back 32

o Day 5-week 6

Front 33

• How long does the early remodeling stage take?

Back 33

o Week 6-8

Front 34

• How long does the middle remodeling stage take?

Back 34

o Weeks 8-12

Front 35

• How long does the late remodeling stage take?

Back 35

o Week 12-final healing

Front 36

• What is the intervention goal during the inflammatory healing stage?

Back 36

o Protect healing tissue from tensile stresses generated by either passive stretch or active muscle contraction

Front 37

• What are the intervention goals during the proliferative healing stage?

Back 37

o Prevent joint contractures
o Prevent adhesions to surrounding structures
o Restore lost cardiovascular fitness
o Avoid tensile stress to healing structures

Front 38

• What are the intervention goals during the early remodeling healing stage?

Back 38

o Facilitate scar remodeling at incision to allow normal ROM and of repair stie to increase resistance to tensile stress
o Avoid excessive tensile force to healing structures
o Restore strength in uninjured muscles

Front 39

• What are the intervention goals during the middle remodeling healing stage?

Back 39

o Facilitate scar remodeling at repair site to resist the force of muscle contraction against resistance
o Avoid excessive tensile force to healing structures
o Restore strength in injured, deconditioned muscles

Front 40

• What is the intervention goal during the late remodeling healing stage?

Back 40

o Restore strength in injured, deconditioned muscles

Front 41

• What is the intervation principle for the inflammatory healing stage?

Back 41

o Immobilization

Front 42

• What is the intervation principle for the proliferative healing stage?

Back 42

o Early protected passive motion
o Cardiovascular conditioning via uninjured structures

Front 43

• What is the intervation principle for the early remodeling healing stage?

Back 43

o Application of gentle stress to injured structures to promote healing via active motion, initially in gravity-eliminated positions
o Avoid painful resistance or ROM strengthening of deconditioned, but uninjured muscles
o Recovery of full joint ROM

Front 44

• What is the intervation principle for the middle remodeling healing stage?

Back 44

o Gradual increase of tensile forces to injured structures via positioning and resistance
o Avoid painful resistance or ROM

Front 45

• What is the intervation principle for the late remodeling healing stage?

Back 45

o Unrestricted use of injured structures

Front 46

• What are ligaments mainly composed of?

Back 46

o Type 1 collagen fibers
o Fibroblast cells
o Extracellular matrix
o Different amount of elastin fibers based on their functional properties

Front 47

• What is ligament consisted of?

Back 47

o 70% water (from GAGs because so hydrophilic)
o 25% collagen
o 4-5% other elements

Front 48

• What is dehydration usually from?

Back 48

o Loss of GAG

Front 49

• Can you stretch a tendon or ligament more?

Back 49

o Ligament because the fibers are a little more loose

Front 50

• Ligaments play a significant role in joint stability by:

Back 50

o Their structure and mechanical properties
 Attachments to bones provide stability and limit mobility of articular structures
o Through their proprioceptive properties
 Have a high density of mechanoreceptors and free nerve endings

Front 51

• What do mechanoreceptors in ligaments do?

Back 51

o They detect and report the amount of force or motion occurring at individual joints to the CNS for regulating muscle activity

Front 52

• What do pain receptors in ligaments do?

Back 52

o Alarm about excessive strain or compression forces applied to the ligaments and also the joint

Front 53

• Mechanical properties of ligaments vary based on?

Back 53

o Location in either intra-articular or extra-articular
o Fiber composition (amount of elastin fibers)

Front 54

• What is the most common ligament injury?

Back 54

o Sprain

Front 55

• What is grade 1 of sprains?

Back 55

o Microscopic ligament fiber tears without any joint laxity

Front 56

• What is grade 2 of sprains?

Back 56

o Partial tearing of ligament fibers with moderate joint laxity

Front 57

• What is grad 3 of sprains?

Back 57

o Complete ligament rupture with marked joint instability and laxity

Front 58

• Do all ligaments heal equally after injury?

Back 58

o No

Front 59

• What type of ligament heals faster?

Back 59

o Extraarticular ligaments (MCL) are faster than intraarticular ligaments (ACL)

Front 60

• What are the three phases of ligament repair?

Back 60

o Phase I: inflammatory reaction
o Phase II: collagen synthesis
o Phase III: remodeling and maturation

Front 61

• Describe the Phase I of the ligament repair

Back 61

o Inflammatory reaction
 Hematoma formation
 Cell migration – phagocytosis
 Release of inflammatory mediators – prostoglandins, histamine, etc.

Front 62

• Describe the Phase II of ligament repair

Back 62

o Collagen synthesis
 Fibroblastic activity
 Production of collage type III
 Conversion of collagen type III to type I

Front 63

• Describe the Phase III of ligament repair

Back 63

o Remodeling and maturation
 Marked increase in concentration of type I collagen
 Collagen reorganization and increase in ligament tensile properties

Front 64

• How long is the healing time for phase I of ligament repair?

Back 64

o Inflammatory reaction is up to 48 hours after injury

Front 65

• How long is the healing time for phase II of ligament repair?

Back 65

o Collagen synthesis is 3-5 weeks

Front 66

• How long is the healing time for phase III of ligament repair?

Back 66

o Remodeling and maturation continues up to 1 year or more

Front 67

• What’s another name for Phase II of ligament healing?

Back 67

o Collagen synthesis
o Proliferative/fibroplastic stage

Front 68

• Ligaments can gain back how much of their tensile strength following complete healing process?

Back 68

o 50-70%

Front 69

• What does ligament repair depend on?

Back 69

o Adequate contact between torn ends
o Adequate immobilization
o Progressive, controlled stress for organized fiber alignment
o Adequate blood supply

Front 70

• Name some effects of immobilization on ligament tissue and associate structures.

Back 70

o Reduced physiologic motin
o Decreased afferent neural input
o Muscular atrophy
o Ligament shortening
o Reduction of water content, proteoglycans and GAGs
o Bone loss, periosteal bone reabsorption
o Articular (hyaline cartilage) erosion
o Reduced ligament weight
o Reduced ligament size
o Reduced ligament strength
o Adhesion formation
o Increased ligament laxity
o Joint stiffness related to synovial membrane adherence

Front 71

• What are the effects of remobilization of ligaments?

Back 71

o After injury, appropriate controlled motion stimulates fiber production and fiber alignment which leads to a structured and organized healing process and promotes regaining of ultimate ligament length

Front 72

• What is the articular cartilage composition?

Back 72

o Cells 3-5%
o Multi-adhesive glycoproteins 5%
o Proteoglycans (aggrecans) 9%
o Collagens 15%
o Intercellular water 60-80%

Front 73

• What are the layers of articular cartilage?

Back 73

o Gliding zone (superficial)
o Transitional zone (middle)
o Radial zone (deep)
o Tidemark
o Calcified zone

Front 74

• Which layer in articular cartilage is the thickest layer and is all collagen and water?

Back 74

o Radial zone (deep)

Front 75

• Which layer is thin layer and glues cartilage to bone?

Back 75

o Tidemark

Front 76

• What kind of orientation of fibers does the gliding zone (superficial) layer have?

Back 76

o Tangential (parallel)

Front 77

• What kind of orientation of fibers does the transitional zone (middle) layer have?

Back 77

o Oblique

Front 78

• What kind of orientation of fibers does the radial zone (deep) layer have?

Back 78

o Vertical

Front 79

• What kind of orientation of fibers does the tidemark layer have?

Back 79

o Tangential

Front 80

• What is the superficial (gliding) zone layer made of?

Back 80

o Water
o Flattened chondrocytes
o Parallel organized CT fibers

Front 81

• What are the middle or transitional zone layer made of?

Back 81

o Chondrocytes
o Randomly arranged collagen fibers

Front 82

• What is the deep (radial) zone layer made of?

Back 82

o High concentration of PGs
o Low water content
o Vertically arranged chondrocytes

Front 83

• What is the calcified zone around?

Back 83

o Compact bone
o Cancellous bone

Front 84

• What gives the articular cartilage a durable and almost friction free surface that can dissipate tensile, compressive, and shear forces applied to the joint?

Back 84

o The parallel organized cartilage fibers in the superficial zone
o Plus a high concentration of GAG and water

Front 85

• What components are most suitable for each function of articular cartilage and why?

Back 85

o Tensile: gliding zone (superficial) b/c of direction of fibers
o Compression: radial zone (deep) b/c of collagen and water
o Shear: gliding zone (superficial)

Front 86

• How does articular cartilage get its nutition?

Back 86

o Because it does not have direct blood supply to it
o Imbibition
o Depends on the appropriate level of physiological stress
o Through compression and stretching, it can get its nutrients like a sponge

Front 87

• What happens if you have excessive loading without adequate unloading periods in articular cartilage?

Back 87

o Could cause cartilage atrophy and degeneration over the contact surfaces

Front 88

• What happens if you have prolonged immobilization (unloading) of articular cartilage?

Back 88

o Could cause chondrocyte necrosis
o Or surface fibrination

Front 89

• What are types of articular degeneration?

Back 89

o Flaky or fraying
o Blisters
o Splitting, clefting, or fissuring

Front 90

• If you have a lesion in cartilage down through the tidemark, then what happens?

Back 90

o Since you have reached a region of vascularity, then it gets into the bone and reaches the nerve endings as well and can start forming a type 1 collagen of fibrocartilage to plug it

Front 91

• If synovial fluid leaks into bone, then what can it cause?

Back 91

o A subchondral bone cyst

Front 92

• Why do superficial lesions of articular cartilage have a much slower repair rate than deeper or even full thickness injuries?

Back 92

o Because there is not enough vascularity
o Do not provoke inflammatory response
o Rely on slow process of chondrocyte proliferation

Front 93

• If you want the inflammatory response after a small injury to cartilage, what do you need to do?

Back 93

o Make a lesion down to the bone to reach blood vessels

Front 94

• After a fibrocartilage plug has formed what should you do with your patient?

Back 94

o After a few days, then put pt. on CPM machine and it will make it more organized

Front 95

• Can stimulate cartilage repair by?

Back 95

o Stimulate it by making holes in it or making a lesion which stimulates bleeding to create a healing bed for the graft
o Make a graft through osteochondreal transplantation
o Autograft chondrocyte implantation
 Get cells from a healthy area and grow in Petri dish then put in

Front 96

• How is healing of cartilage monitored?

Back 96

o MRI

Front 97

• Postoperatively, what happens to the knee?

Back 97

o 4 weeks of non-bearing
o Use CPM for 6 hours every day for 4 weeks
o Hinged neoprene brace is used for support and to guard the knee
o Deep water workouts and stationary bike for non-involved side and after two weeks both legs
o Strengthening exercises introduced
o Gradual return to sports after 3 months
o Impact exercises discouraged for 12 months though for pain relief and graft maturity

Front 98

• What are the objectives of bone fragment management?

Back 98

o Fragment reduction
o Maintenance of alignment
o Restoration of function

Front 99

• Three types of bone cells

Back 99

o Osteoblasts
o Osteocytes
o Osteoclasts

Front 100

• What are osteoblasts?

Back 100

o These cells produce type I collagen and form the bone matrix

Front 101

• What are osteocytes?

Back 101

o These cells represent about 90% of mature bone structure
o They control the level of extracellular concentration of calcium and phosphorus

Front 102

• What are osteoclasts?

Back 102

o These cells are responsible for bone resorption
o They produce specific acidic enzyme which reduces the bone pH level, increasing calcium and phosphate solubility and bone resorption

Front 103

• What kind of bone fixations can you have?

Back 103

o External fixation: casting
o Internal fixation: plates with screws

Front 104

• Types of bones

Back 104

o Cortical: tightly packed osteons; mainly in shaft of long bones
o Cancellous: msh work of trabecules; formed at metaphysic area of long bones, body of vertebrae, and cuboid bones

Front 105

• What are the stages of fracture healing in bone?

Back 105

o Interfragmentary stabilization
o Bone union
o Remodeling and functional adaptation

Front 106

• What happens during the interfragmentary stabilization stage?

Back 106

o In this stage, the fracture fragments are held together by periostial and fibrocartilage soft callus formation

Front 107

• What happens during the bone union stage?

Back 107

o This is the healing stage; new boney tissue is formed through intermembranous ossification

Front 108

• What happens during remodeling and functional adaptation stage?

Back 108

o Newly formed bony structure is modified and adapted to the required function (weight bearing, flexibility, etc.)

Front 109

• What are the six phases in fracture healing?

Back 109

o Inflammation and hematoma formation
 Fibrin clot formation and proliferation of fibroblasts and osteoblasts
o Chondrocyte formation and angiogenesis (new vascularization)
o Cartilage formation and calcification
 Callus formed and aligned; (Wolf’s law here)
o Cartilage removal
 Callus is reabsorbed and anatomical shape of bone is regained
o Bone formation
 Bone fragments connected together
o Bone remodeling
 Can take a few years, functional activity shapes and strengthens bone

Front 110

• What is Wolf’s law?

Back 110

o Indicates that changes in bone function and changes in the amount of stress applied to a bone could result in definite structural changes in bones

Front 111

• How long does it take for bone to heal?

Back 111

o 8-12 weeks

Front 112

• Does non weight bearing or weight bearing heal faster?

Back 112

o Non-weight bearing

Front 113

• List some factors that delay bone healing

Back 113

o Poor nutrition and smoking
o Inadequate bone reduction
o Inadequate immobilization
o Soft tissue entrapment between bone fragments
o Infection
o Inadequate blood and vascular supply

Front 114

• List some stimulations of bone healing process

Back 114

o Bone grafts
 Bone autograft
 Bone allograft
 Ceramic bone grafts
o Application of electromagnetic fields to the fracture site
 Negative charge will attract calcium
o Use of low intensity pulsed ultrasound
o Application of controlled stress to the fracture site

Front 115

• What is a bone autograft?

Back 115

o Bone tissue taken from other bones of the same person

Front 116

• What is a bone allograft?

Back 116

o Bone tissue taken from bone of external sources

Front 117

• What is ceramic bone grafts?

Back 117

o Graft substitutes made of calcium and phosphate composites

Front 118

• What are some complications of bone healing?

Back 118

o Delayed union (not healing in supposed time)
o Non-union
o Mal-union (bad union)