Anterior Cruciate Ligament (ACL)

Chapter 08

APR Enhanced Lecture Slides

See separate PowerPoint slides for all figures and tables pre-inserted into PowerPoint without notes and animations.

8-1

8-2 8.1 Classes of Joints

• Structural: based on major connective tissue type that binds bones – Fibrous – Cartilaginous – Synovial • Functional: based on degree of motion – Synarthrosis: non-movable – Amphiarthrosis: slightly movable – Diarthrosis: freely movable

8-3 Fibrous Joints

• Characteristics – United by fibrous connective tissue – Have no joint cavity – Move little or none • Types: Sutures, Syndesmoses, Gomphoses

8-4 Fibrous Joints

Class and Bones or Structures Example of Joint Joined Movement

Fibrous Joints Sutures Coronal Frontal and parietal None Lambdoid Occipital and parietal None Sagittal The two parietal bones None Squamous Parietal and temporal Slight Syndesmoses Radioulnar Ulna and radius Slight Stylohyoid Styloid process and Slight hyoid bone

Stylomandibular Styloid process and Slight mandible Tibiofibula Tibia and fibula Slight Gomphoses Dentoalveolar Tooth and alveolar process Slight

Cartilaginous Joints Synchondroses Epiphyseal plate Diaphysis and epiphysis None of a long bone Sternocostal Anterior cartilaginous part Slight of first rib; between rib and sternum

Sphenooccipital Sphenoid and occipital None Symphyses Intervertebral Bodies of adjacent Slight vertebrae

Manubriosternal Manubrium and body None of sternum

Symphysis pubis The two coxal bones None except during childbirth Xiphisternal Xiphoid process and None body of sternum 8-6 Fibrous Joints: Sutures

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Opposing bones interdigitate. • Periosteum of one bone is Frontal continuous with the periosteum bone of the other. • Sutural ligament: two Coronal suture periostea plus dense, fibrous, connective tissue between. Parietal • In adults may ossify Sagittal bone suture completely: synostosis. • Fontanels: membranous areas

Lambdoid in the suture between bones. suture Occipital Allow change in shape of head bone during birth and rapid growth of the brain after birth.

Parietal bone Frontal Squamous bone suture Coronal suture

Occipital bone Lambdoid suture Mastoid (posterolateral) fontanel Sphenoidal (anterolateral) fontanel (a) Lateral view Temporal bone

Frontal bones (not yet fused into a single bone)

Frontal (anterior) fontanel

Parietal Sagittal bone suture

Occipital (posterior) Occipital fontanel bone 8-8 (b) Superior view Fibrous Joints: Syndesmoses

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Bones farther apart than suture and joined Head of radius Annular ligament by ligaments Biceps brachii tendon Oblique cord • Some movement may occur Radioulnar syndesmosis Radius • Examples: radioulnar

Interosseous membrane (interosseus

Ulna membrane)

Anterior view

8-9 Fibrous Joints: Gomphoses

Gingiva (gum) • Periodontal ligaments: hold teeth in place

Root • Inflammations of tooth – Gingivitis leads to… Periodontal ligaments – Periodontal disease Gomphosis

Alveolar bone

8-10 Cartilaginous Joints

• Unite two bones by means of cartilage • Types – Synchondroses: hyaline cartilage – Symphyses: fibrocartilage

8-11 Cartilaginous Joints Synchondroses

12 Cartilaginous Joints: Synchondroses

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Joined by hyaline cartilage Epiphysis Synchondroses Ilium (epiphyseal plates) Secondary • Little or no movement epiphysis • Some are temporary and Diaphysis are replaced by synostoses

Ischium Pubis • Some are permanent Synchondroses (a) Lateral view (b) Frontal section • Some like costochondral First rib

Sternocostal synchondrosis joints develop into (costal cartilage Manubriosternal of first rib) symphysis synovial joints Manubrium

Sternal Body Sternum symphyses Xiphoid process • Examples: Epiphyseal Xiphisternal symphysis plates, sternocostal, Costochondral joint sphenooccipital

8-13 Cartilaginous Joints Symphyses

Pubic symphysis

Intervertebral discs14 Cartilaginous Joints: Symphyses • Fibrocartilage uniting two bones • Slightly movable • Examples: symphysis pubis, between the manubrium sternum and the body of the sternum, intervertebral disks.

Ilium Sacrum

Pubis Symphysis pubis Ischium

8-15 Anterior view Synovial Joints

• Contain synovial fluid • Allow considerable movement • Most joints that unite bones of appendicular skeleton reflecting greater mobility of appendicular skeleton compared to axial • Complex

8-16 Synovial Joints Synovial Joints • Articular cartilage: hyaline; provides smooth surface • Joint cavity: synovial; encloses articular surfaces • Capsule – Fibrous capsule: dense irregular connective tissue, continuous with fibrous layer of the periosteum. Portions may thicken to form ligaments. – Synovial membrane and fluid: membrane lines inside of joint capsule except at actual articulation of articular cartilages. Thin, delicate. Sometimes separated from fibrous capsule by areolar C.T. and fat, sometimes merged with fibrous. • Synovial fluid: complex mixture of polysaccharides, proteins, fat and cells. Hyaluronic acid- slippery. • No blood vessels or nerves in articular cartilages; nutrients from nearby blood vessels and synovial fluid • Nerves in capsule help brain know position of joints (proprioception) 8-18 Synovial Joints

Synovial Nerve membrane Joint Fibrous capsule capsule

Bone

Joint cavity (filled with synovial fluid)

Articular cartilage

Tendon sheath

Tendon Fibrous layer Bone Periosteum Cellular layer 8-19 Accessory Structures

• Bursae – Pockets of synovial membrane and fluid that extend from the joint. Found in areas of friction – Bursitis • Ligaments and tendons: stabilization • Articular discs: temperomandibular, sternoclavicular, acromioclavicular • Menisci: fibrocartilaginous pads in the knee. • Tendon sheaths: synovial sacs that surround tendons as they pass near or over bone

8-20 Ligaments

Articular Lateral disc meniscus

Lateral Anterior collateral cruciate ligament ligament

Tendon Tendons sheaths Bursae

8-21 Types of Synovial joints

• Uniaxial: occurring around one axis • Biaxial: occurring around two axes at right angles to each other • Multiaxial: occurring around several axes

Class and Example Structures Joined Movement of Joint Plane Acromioclavicular Acromion process of Slight scapula and clavicle Carpometacarpal C a r pa ls a nd me ta ca r pa ls 2 –5 Slight Costovertebral Ribs and vertebrae Slight Intercarpal Between carpal bones Slight Intermetatarsal Between metatarsal bones Slight Intertarsal Between tarsal bones Slight Intervertebral Between articular processes of Slight adjacent vertebrae Sacroiliac Between sacrum and coxal bone Slight Plane Intervertebral (complex joint with several planes and synchondroses) Tarsometatarsal Tarsal bones and metatarsal Slight bones

Saddle Carpometacarpal Carpal and metacarpal Two axes pollicis of thumb Intercarpal Between carpal bones Slight Sternoclavicular Manubrium of sternum Slight and clavicle

Saddle Carpometacarpal

Hinge Cubital (elbow) Humerus, ulna, and radius One axis Knee Femur and tibia One axis Interphalangeal Between phalanges One axis Talocrural (ankle) Talus, tibia, and fibula Multiple axes; one predominates

Hinge Cubital

Pivot Atlantoaxial Atlas and axis Rotation Proximal radioulnar Radius and ulna Rotation Distal radioulnar Radius and ulna Rotation

Pivot Proximal radioulnar

Ball-and-Socket Coxal (hip) Coxal bone and femur Multiple axes Glenohumeral Scapula and humerus Multiple axes (shoulder)

Ball-and-socket Glenohumeral

Ellipsoid Atlantooccipital Atlas and occipital bone Two axes Metacarpopha- Metacarpal bones and Two axes langeal (knuckles) phalanges Metatarsopha- Metatarsal bones and Two axes langeal (ball of foot) phalanges Radiocarpal (wrist) Radius and carpal bones Multiple axes Temporomandibular Mandible and temporal bone Multiple axes; one predominates

Ellipsoid Atlantooccipital 8-23 Plane and Saddle Joints

• Plane or gliding joints – Uniaxial. some rotation possible but limited by surrounding structures – Example: intervertebral, intercarpal, acromioclavicular, carpometacarpal, costovertebral, intertarsal, sacroiliac, tarsometatarsal • Saddle joints – Biaxial – Example: thumb (carpometacarpal pollicis), intercarpal, sternoclavicular

8-24 Gliding (Plane) Joints

Between articular processes of adjacent vertebrae Wrist Ankle

Sacroiliac joint Ribs 2-7 connecting to sternum Saddle Joint

Between trapezium and metacarpal of thumb Hinge and Pivot Joints

• Hinge joints – Uniaxial – Convex cylinder in one bone; corresponding concavity in the other – Example: elbow, ankle, interphalangeal • Pivot joints – Uniaxial. Rotation around a single axis. – Cylindrical bony process rotating within a circle of bone and ligament – Example: articulation between dens of axis and atlas (atlantoaxial), proximal radioulnar, distal radioulnar 8-27

Hinge Joint

Joints between Elbow joint phalanges (Humeroulnar joint) Pivot Joint

Elbow joint Between Atlas (C1) and Axis (C2) (Humeroradial joint) (Atlantoaxial joint) Ball-and-Socket and Ellipsoid Joints

• Ball-and-socket – Multiaxial – Examples: shoulder and hip joints

• Ellipsoid (Condyloid) – Modified ball-and-socket; articular surfaces are ellipsoid – Biaxial – Example: atlantooccipital,

8-30 Ball-and-Socket Joint

Shoulder joint Hip Joint

Ball-and-Socket Joint

Shoulder joint Hip Joint

Condyloid (Ellipsoidal) Joint

Metacarpophalangeal joints 8.2 Types of Movement

• Gliding: in plane joints; slight movement • Angular – Flexion and Extension • Hyperextension • Plantar and Dorsiflexion – Abduction and Adduction • Circular – Rotation – Pronation and Supination – Circumduction

8-34 Flexion and Extension Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Flexion

Extension

© The McGraw-Hill Companies, Inc./Eric Wise, photographer Extension © The McGraw-Hill Companies, Inc./Eric Wise, photographer • Flexion: movement of a body part anterior to the coronal plane • Extension: movement of a body part posterior to 8-35 the coronal plane Flexion and Extension

Anterior to Posterior to coronal plane coronal plane

Anterior to Posterior to coronal plane coronal plane Anterior to Posterior to frontal plane frontal plane

Flexion Extension

(a) Coronal plane (b) Coronal plane (c) Coronal plane

• Exceptions to definition – Plantar flexion: standing on the toes – Dorsiflexion: foot lifted toward the shin

Dorsiflexion

Plantar flexion 8-37 © The McGraw-Hill Companies, Inc./Eric Wise, photographer Abduction and Adduction Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Abduction

Abduction • Abduction: movement away from the median plane Abduction Adduction • Adduction: movement toward the median plane

Adduction

(a) (b) a: © The McGraw-Hill Companies, Inc./Jill Braaten, Photographer; b,: © The McGraw-Hill Companies, Inc./Eric Wise, photographer 8-38 Circular Movements

• Rotation: turning of a structure on its long axis – Examples: rotation of the head, humerus, entire body – Medial and lateral rotation; example, the rotation of the © The McGraw-Hill Companies, Inc./Eric Wise, photographer arm Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Pronation • Pronation/Supination: refer to unique rotation of the forearm – Pronation: palm faces posteriorly – Supination: palm faces anteriorly 8-39 Supination © The McGraw-Hill Companies, Inc./Eric Wise, photographer Circular Movement Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

• Circumduction – Combination of flexion, extension, abduction, adduction – Appendage describes a cone Circumduction

8-40 © The McGraw-Hill Companies, Inc./Eric Wise, photographer Special Movements

• Unique to only one or two joints • Types – Elevation and Depression – Protraction and Retraction – Excursion – Opposition and Reposition – Inversion and Eversion

8-41 Elevation and Depression • Elevation: moves a structure superior • Depression: moves a structure inferior • Examples: shrugging the shoulders, opening and closing the mouth Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Elevation Depression

• Protraction: gliding motion anteriorly • Retraction: moves structure back to Protraction anatomic position or even further posteriorly • Examples: scapulae and mandibles

Retraction

Lateral excursion Lateral excursion to the right to the left

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Opposition Reposition • Opposition: movement of thumb and little finger toward each other • Reposition: return to anatomical position

8-45 Inversion and Eversion

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Inversion: turning the ankle so the plantar surface of foot faces medially • Eversion: turning the ankle so the plantar surface of foot faces laterally

Eversion Inversion

8-46 8.3 Range of Motion

• Amount of mobility demonstrated at a given joint • Types – Active: amount of movement accomplished by muscle contraction – Passive: amount of movement accomplished by some outside force • Both active and passive can be influenced by 1. Shape of articular surfaces forming joint 2. Amount and shape of cartilage covering surfaces 3. Strength and location of ligaments and tendons 4. Location of muscles associated with joint 5. Amount of fluid in and around joint 6. Amount of pain in and around joint 7. Amount of use/disuse of joint

8-47 8.4 Temporomandibular Joint

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • TMJ Lateral view • Combination plane and Temporal bone Zygomatic arch ellipsoid joint External auditory canal Lateral ligament

Joint capsule Styloid process • Fibrocartilage disk divides

Stylomandibular ligament joint into superior and Mandible inferior cavities

Temporal bone Superior joint cavity Articular disk • Allows Inferior joint cavity depression/elevation, Lateral pterygoid muscle Mandibular condyle Mandible excursion,

Sagittal section of temporomandibular joint protraction/retraction • TMJ Disorders – Cause of most chronic orofacial pain

8-48 Temporomandibular Joint (TMJ) Temporomandibular Joint (TMJ) Temporomandibular Joint (TMJ) Temporomandibular Joint (TMJ) Temporomandibular Joint (TMJ)

Condylar Process of Mandible Temporomandibular Joint (TMJ)

Coronoid Process of Mandible Temporomandibular Joint (TMJ)

Zygomatic Arch of Temporal Bone Temporomandibular Joint (TMJ)

Mandibular Fossa of Temporal Bone Temporomandibular Joint (TMJ)

Articular Tubercle of Temporomandibular Joint Temporomandibular Joint (TMJ)

Articular Disc of Temporomandibular Joint Temporomandibular Joint

Mandibular Fossa of Temporal bone Mandibular condyle of Mandible Temporomandibular Joint (TMJ) Temporomandibular Joint (TMJ) Temporomandibular Joint (TMJ) Shoulder (Glenohumeral) Joint • Ball-and-socket: stability is reduced, mobility is increased compared to hip • Flexion/extension, abduction/adduction, rotation, circumduction • Glenoid labrum: rim of fibrocartilage built up around glenoid cavity; joint capsule attachment • Bursae: subacromial and subscapular • Rotator cuff: four muscles that along with ligaments give stability to the joint • Tendon of biceps brachii passes through the joint capsule 8-63 Glenohumeral Joint Shoulder Xray

Humerus Rib 1

Acromioclavicular Shaft of humerus joint

Surgical neck of humerus Clavicle

Head of humerus Intertubercular Greater tubercle sulcus Lesser tubercle Shoulder Xray

Scapula Glenoid cavity

Lateral border of Superior angle of scapula scapula

Medial border of scapula Coracoid process

Inferior angle of scapula Infraglenoid Spine of scapula Acromion tubercle Glenohumeral Joint

Virtual Dissection Glenohumeral Joint Glenohumeral Joint Glenohumeral Joint Glenohumeral Joint

Fibrous Capsule of Glenohumeral Joint Glenohumeral Joint Glenohumeral Joint

Tendon of Long Head of Biceps Brachii Glenohumeral Joint Glenohumeral Joint

Clavicle Glenohumeral Joint

Scapula Glenohumeral Joint

Acromion Process Glenohumeral Joint

Coracoid Process Glenohumeral Joint

Humerus Glenohumeral Joint

Head of Humerus Glenohumeral Joint

Glenoid Cavity Muscles Acting on Humerus – Rotator Cuff Supraspinatus origin insertion Muscles Acting on Humerus – Rotator Cuff - Infraspinatus

origin insertion Muscles Acting on Humerus – Rotator Cuff – Teres Minor

insertion origin Muscles Acting on Humerus – Rotator Cuff - Subscapularis insertion

Clavicle (cut and elevated) Acromioclavicular ligament Acromion process Trapezoid ligament Coracoclavicular Conoid ligament Coracoacromial ligament ligament Subacromial bursa Transverse scapular ligament Coracohumeral ligament Coracoid process Humerus Superior glenohumeral ligament Transverse Middle glenohumeral ligament humeral ligament Inferior glenohumeral ligament Tendon sheath on Joint capsule tendon of long head of biceps brachii Triceps brachii tendon (long head) Biceps brachii (long head) tendon Hook retracting subscapularis muscle Anterior view

Acromion process (articular surface)

Subacromial bursa Joint cavity Articular cartilage over head of humerus Articular cartilage Tendon sheath on over glenoid cavity tendon of long head Scapula (cut surface) of biceps brachii Glenoid labrum

Biceps brachii Joint capsule (long head) tendon

Humerus

Humerus Joint capsule • Compound hinge joint Synovial membrane Joint cavity Fat pad Articular cartilage – Humeroulnar joint

Coronoid Trochlea process – Humeroradial joint Ulna Articular cartilage of the trochlear notch

(a) Sagittal section – Proximal radioulnar joint

Humerus Radial annular Lateral ligament (cut) • Shape of trochlear notch and epicondyle Biceps Joint brachii capsule tendon (cut) trochlea limit movement to Radial collateral Radius ligament (cut) Interosseus Olecranon membrane extension and flexion process Ulna Olecranon bursa (b) Lateral view • Rounded head of radius allows pronation and supination Radial annular Humerus ligament Medial Biceps brachii epicondyle tendon • Ligaments Joint capsule Radius Ulnar collateral Interosseus ligament membrane – Ulnar collateral ligament Olecranon Ulna process Olecranon (c) Medial view bursa – Radial collateral ligament

Humerus Radial annular – Radial annular ligament ligament Biceps Lateral brachii epicondyle tendon (cut) Joint capsule Radius • Subacromial bursa Radial collateral Interosseus ligament membrane Olecranon Ulna process 8-92 Olecranon bursa (d) Lateral view Elbow Joints

Humeroradial Humeroulnar Joint Joint Elbow Elbow -2 joints in one Humeroulnar & Humeroradial Elbow Joints

Virtual Dissection Elbow Joints Elbow Joints Elbow Joints

Fibrous Capsule of Elbow Elbow Joints

Anular Ligament Elbow Joints

Radial Collateral Ligament Elbow Joints

Ulnar Collateral Ligament Elbow Joints Elbow Joints

Humerus Elbow Joints

Capitulum Trochlea Elbow Joints

Lateral Medial Epicondyle Epicondyle Elbow Joints

Head of Radius Radius Radial Tuberosity Elbow Joints

Ulna Elbow Xrays

Lateral View

A-P View Hip (Coxal) Joint • Ball-and-socket with acetabulum deepened by fibrocartilage acetabular labrum and transverse acetabular ligament • More stable but less mobile than shoulder joint • Flexion/extension, abduction/adduction, rotation, circumduction • Extremely strong joint capsule reinforced by ligaments including the iliofemoral ligament that bears much of the body weight while standing • Ligament of head of femur (round ligament of femur); often bears nutrient artery

8-110 Coxal (Hip) Joint

Anterior Posterior Coxal (Hip) Joint

Anterior Posterior

Ball and Socket Joint Coxal (Hip) Joint Head of femur Hip and Thigh Xray Obturator foramina

Iliac crest Pubic symphysis

Ischial tuberosity Sacroiliac joints

Greater trochanter Lesser trochanter Sacrum Coxal (Hip) Joint

Hip Fracture Coxal (Hip) Joint

Head of Femur Iliac Crest

Greater Ischial Trochanter Tuberosity Coxal (Hip) Joint

Virtual Dissection Coxal (Hip) Joint Coxal (Hip) Joint Coxal (Hip) Joint Coxal (Hip) Joint Coxal (Hip) Joint Coxal (Hip) Joint Coxal (Hip) Joint Coxal (Hip) Joint

Head of Femur Acetabulum Coxal (Hip) Joint

Coxal bone Tendon of rectus Articular cartilage femoris muscle (cut) Acetabular Acetabulum Iliofemoral labrum Joint cavity ligaments Pubofemoral Joint Ligament of head of femur Greater capsule ligament Head of femur trochanter Greater trochanter Transverse acetabular Lesser ligament Femur trochanter

Lesser trochanter Femur (a) Anterior view (b) Frontal section

Acetabular labrum Ligament of head of femur Head of femur

Articular capsule (cut)

• Condyloid: allowing flexion/extension, small amount of rotation • Menisci: fibrocartilage articular disks that build up the margins of the tibia and deepen articular surface • Cruciate ligaments: extend between intercondylar eminence of tibia and fossa of the femur – Anterior cruciate ligament (ACL). Prevents anterior displacement of tibia – Posterior cruciate ligament (PCL). Prevents posterior displacement of tibia • Collateral and popliteal ligaments: along with tendons of thigh muscles strengthen the joint • Bursae: may result in slow accumulation of fluid in the joint (water on the knee)

8-129 Knee – Most Complex Joint Knee Surface Projection of Patella Surface Projection of Patellar Ligament Surface Projection of Tibial Tuberosity Knee Xrays

A-P View P-A View Lateral View Knee Xray: A-P View Epiphyseal line

Femur Patella

Knee joint cavity Head of fibula

Tibia Fibula Neck of fibula Tibial tuberosity

Lateral condyle Intercondylar Median condyle of Lateral condyle of Medial condyle of tibia Shaft of fibula eminence femur femur of tibia Knee Xray: A-P View Quadriceps femoris m. Biceps femoris m.

Soleus m. Knee Xray:

Medial Lateral P-A View epicondyle epicondyle

Patella Femur

Articular surface of femur Adductor tubercle

Medial condyle Lateral of femur condyle of Tibia Fibula femur

Medial condyle Lateral of tibia condyle of Knee joint cavity tibia Knee Xray: P-A View

Epiphyseal line Head of fibula

Quadriceps femoris m.

Intercondylar Neck of fibula eminence

Popliteal surface

Intercondylar fossa Shaft of fibula Soleus m. Knee Xray: Lateral View

Adductor Intercondylar tubercle eminence Tibia

Articular surface Tendon of of lateral quadriceps condyle Fibula femoris m.

Articular surface of medial Tibial condyle Femur Patella tuberosity Knee Femur Patella Tibia Fibula Anterior Knee Posterior Knee Anterior Posterior Medial Meniscus Lateral Meniscus Tibial (Medial) Collateral Ligament Fibular (Lateral) Collateral Ligament Anterior Cruciate Ligament Transverse Ligament Posterior Meniscofemoral Ligament Posterior Cruciate Ligament Knee MRI Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Femur Knee

Suprapatellar Quadriceps bursa femoris muscle (cut)

Quadriceps femoris tendon Patellar surface of femur Posterior cruciate Lateral (fibular) Patellar ligament collateral ligament retinaculum Lateral condyle Patella in Medial condyle Lateral (fibular) quadriceps Medial (tibial) collateral ligament Anterior cruciate tendon collateral ligament Lateral ligament meniscus Medial meniscus Tendon of biceps femoris Tendon of T ransverse ligament muscle (cut) Patellar ligament Biceps femoris Medial (tibial) muscle (cut) collateral ligament

Fibula Tibia Fibula Tibia

(a) Anterior view (b) Anterior view

Tendon of adductor magnus muscle (cut) Femur Quadriceps femoris muscle (cut) Femur

Medial head of Anterior gastrocnemius Lateral head of cruciate Lateral condyle muscle (cut) gastrocnemius ligament Lateral (fibular) muscle (cut) collateral ligament Medial Medial (tibial) condyle Posterior collateral Arcuate popliteal meniscofemoral ligament ligament Medial ligament meniscus Oblique Tendon of biceps Lateral meniscus popliteal femoris muscle (cut) Medial ligament Lateral (fibular) (tibial) collateral Posterior cruciate Tendon of collateral ligament ligament ligament semimembranosus Popliteus muscle muscle (cut) Tibia Fibula Tibia Fibula 8-158

Quadriceps femoris tendon Posterior cruciate Suprapatellar Femur ligament bursa Medial Subcutaneous Lateral (tibial) prepatellar (fibular) collateral bursa collateral ligament ligament Patella Anterior Lateral cruciate Articular Fat pad meniscus ligament cartilage Patellar Medial Meniscus ligament meniscus Deep infrapatellar bursa

Tibia

8-159 8-160 Knee Injuries and Disorders • Football injuries: often Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. tear the tibial collateral ligament, the anterior cruciate ligament, and Lateral Medial damage the medial meniscus • Bursitis Direction of force Medial (tibial) • Chondromalacia: collateral ligament softening of cartilage due to abnormal movement of Anterior cruciate Medial ligament meniscus the patella or to accumulation of fluid in fat pad posterior to patella • Hemarthrosis: acute accumulation of blood in Anterior view joint 8-161 Ankle (Talocrural) Joint

Tibia (medial malleolus) Medial ligament • Highly modified hinge joint Plantar calcaneonavicular ligament Calcaneal • Lateral and medial tendon (cut) Plantar calcaneo- cuboid thickening of articular ligament Talus capsule to prevent side-to- Long plantar ligament Calcaneus side movement (a) Medial view • Dorsiflexion/plantar flexion, limited inversion and Tibia Posterior Fibula eversion tibiofibular (lateral malleolus) ligament Calcaneofibular Anterior tibiofibular ligament • Ligaments of arch ligament Anterior talofibular ligament

Calcaneal – Hold bones in proper Tendon of tendon (cut) fibularis Long longus relationship plantar muscle ligament Tendon of – Transfer weight Calcaneus fibularis brevis (b) Lateral view muscle 8-162 Foot Xrays Dorsal view

Lateral View 7 Tarsal Bones

Talus Calcaneus Cuboid

Cuneiforms Medial Intermediate Lateral Navicular Foot Xray: Lateral View

Fibula

Medial Navicular Tuberosity Tibia cuneiform of calcaneus

Direction of force Torn fibers of anterior talofibular ligament

Torn fibers of calcaneofibular ligament

Lateral view 8-169 8-170 8.5 Effects of Aging on Joints

• Tissue repair slows; rate of new blood vessel development decreases • Articular cartilages wear down and matrix becomes more rigid • Production of synovial fluid declines • Ligaments and tendons become shorter and less flexible: decrease in range of motion (ROM) • Muscles around joints weaken • A decrease in activity causes less flexibility and decreased ROM

8-171 Joint Disorders • Arthritis – Osteoarthritis: wear and tear – Rheumatoid: caused by transient infection or autoimmune disease • Joint infections. Lyme disease (with ticks as vector), suppurative arthritis, tuberculous arthritis • Gout. Metabolic disorders of unknown cause (idiopathic). Increase in uric acid in blood results in deposition of monosodium urate crystals in joints and kidneys • Hallux valgus and bunion. Caused by ill-fitting shoes • Joint replacement. Prosthetic joint used to

(a) (b)

a: © James Stevenson/Science Photo Library/ Photo Researchers, Inc.; b: © CNRI/Science Photo Library/Photo Researchers, Inc.

8-173