• Joints (general)• Joints of the upper limb• Joints of the lower limbChapter 9 of Tortora Human anatomy

Lecturer: Dr. M. SamsamUniversity of Central Florida, Orlando,

Pictures from Platzer atlas and textbook

of human anatomy and K. Moore anatomy

Types of Joints:1- Continuous (synarthroses)2- Discontinuous (diarthroses)

Continuous Joints:1- Fibrous (syndesmosis)2- Cartilaginous (synchondrosis)

1- Fibrous joints: examples: Interosseous memb. Ligamentum Flavum Sutures of the skull Gomphosis

2- Cartilaginous:Primary: Hyaline cartilage between the bones, e.g.: Epiphysial disk. eg: between the epiphysis and the diaphysis, orthe joints between the 3 parts of the hip bone.

Secondary: Symphysis

Discontinuous Joints: (Diarthroses or Synovial joints)

1- Articular surfaces: Hyaline or Fibrocartilage2- Articular capsule: composed of Synovial and Fibrous membranes3- Joint cavity: Synovial fluid

*Angle of excursion

Synovial joints:Additional features: (Possibly) Ligaments Intercalated disks-menisci Articular lip Bursa

Restricting features: Ligaments Bones Soft tissue

Factors keeping Contact between the articular surfaces:MusclesCapsular ligamentsSurface adhesionAtmospheric pressure

*Pathology: Degeneration of cartilage Ankylosis

*Classification of synovial joints:

1-Axes2-degree of freedom3-number of articular surfaces4-shape:

1- Plane joints2- Hinge (ginglymus) joints3- pivot (trochoid) joints4- Ellipsoidal joints:5- Saddle (Sellar) joints:6- Ball-and-Socket joints:

Fixed joints: (Amphiarthrosis)

Sternoclavicular joint: synovial*Saddle type but acts as Ball and socket jointArticular surfaces:Sternal end of clavicle and the manubrium.Articular disk (9).anterior (10) and posterior sternoclavicular and interclavicular ligaments (11).

Costoclavicular ligament (8) also supporting the joint.

*3 degrees of freedom.Clavicle moves at about 60o by arm elevation.*Movements: elevation and depression of shoulder protraction, retraction and circumduction.

Acromioclavicular joint: synovialPlane joint, Articular surfaces: Acromial surface of clavicle and Acromion process of scapulaacromioclavicular lig.(13)It moves in combination with sternoclavicular Joint.

*Shoulder joint:Ball and socketBetween head of the humerus (ball)and glenoid cavity (socket)Hyaline cartilage covering the surfacesThe cavity is enlarged by articular lip.No strong ligamentsMuscles strengthen the joint (rotator cuff muscles) Axillary recess (6)Long head of biceps brachii muscle passes throughbicipital groove and actually originates from supraglenoid tubercle.

The capsule is supported by:Coracohumaral Ligament superiorly (7) and 3 weak glenohumeral ligaments (sup, middle, inf).

A few bursae are associated with joint: subcoracoid.Coracoacromial ligament (10) restricts the movement

Movements:3 degrees, multi-axial , Abduction, adductionanteversion (flexion), retroversion (extension),lateral and medial rotation and circumduction

Dislocation is common: anterior dislocation:Injury to the axillary nerve.

*Elbow joint:Is a compound joint, composed of :Humeroradial, humeroulnar and proximal radioulnarJoints.1- joint capsule, is lax and strengthened by brachialis and triceps muscles.2- humeral epicondyles (outside the capsule) 3- Synovial membrane, 4- Fibrous membrane5- Fatty tissue, 8- Annular ligament of the radius9- Superior recessus sacciformis10- Ulnar collateral ligament11- anterior fibers, 12- posterior fibers, 13- oblique F.14- Radial collateral ligament

Quadrate ligament: connects the neck of radius toThe radial notch of ulna

Movements:Flexion, extension, supination and pronation

Ulnar (medial) collateral ligament injury sprain: Leads to abnormal abduction of the forearm.

Radial (lateral) collateral ligament injury sprain:Adduction of forearm is disturbed.

*Pulled elbow: subluxation of the head of the radiusReduction: pressing radial head posteriorly (elbow flexed), then extend and supinate the forearm

Elbow joint, continuedHumeroradial joint:Is a ball and socket like joint but doesn’t function so.Humeroulnar is a hinge joint

*Joints between radius and ulna:

A- Proximal radioulnar joint is a pivot joint

B- Inerosseous membrane between radius and ulna(continuous fibrous joint)

C- Distal Radioulnar joint: Pivot jointBetween head of Ulna and ulnar notch of Radius7- Inferior recessus sacciformisProximal and distal radioulnar joints are necessarilycombined joints to permit pronation and supination

Wrist (radiocarpal) joint: synovialEllipsoid type,Surfaces: Proximally by Radius and articular disk,and distally by proximal row of carpal bones.Movements: Abduction (radial deviation)Adduction (ulnar deviation), Flexion and Dorsiflexion (extension) and circumduction

Ligaments: ulnar collateral ligament (8)Radial collateral ligament (9)Palmar radiocarpal lig (10), dorsal radiocarpal lig (11)Palmar ulnocarpal lig (12)And many other ligaments

The joint between carpal bones (midcarpal) isS shape. There is a little movement between thebones of first row but almost no movement between the 2nd row and between these and the metacarpals.

Carpometacarpal joint of the thumb:Saddle joint (synovial)Movements: Abduction, adduction, opposition, reposition and circumduction

Carpometacarpal joints:Are Amphiarthroses (synovial joints)(almost no movement)

Metacarpophalangeal joints: synovialAre ball and socket in shape but restrictedmovements due to collateral ligaments.Passive rotation of 50o might be possible

Interphalangeal joints: synovialHinge joints: Collateral and palmar ligamentsMovements: flexion and extension

Hip joint:Ball and socket type*Articular surfaces*Joint movements:*Innervation: Sciatic N., Femoral N. and Obturator N.

* The joint has five ligaments: *Four of them are extracapsular:Ilio-femoral ligament (10):Lateral part: prevents lateral rotation and adduction of femurMedial part: prevents medial rotation of femur

Ischio-femoral ligament (12):prevents medial rotation of femur

Pubo-femoral lig (13):prevents femur abduction

Orbicular zone (11):Maintain contact between the headand the socket.

Ligament of the head of the femur (6):Intracapsular, contains the Acetabular artery coming from Obturator artery.

Weight bearing line

Knee joint: Largest jointSupporting body weight

*Side supporting ligaments:Collateral ligaments:The medial (tibial) collateral ligament (9) and The lateral collateral ligament (15) and the Iliotibial tract

External ligaments:Collateral ligaments (9 and 15)Lateral + medial pathelar retinaculum (5,6)Patellar ligament (2)Oblique popliteal ligament (18)Arcuate popliteal ligament (19)

14- tendon of semimembranous M.21- poplital M.24-25) med and lat heads of gastrocnemius

Knee joint:

Synovial membraneInnervation

Only look

1- synovial membrane2- fibrous membrane5- suprapateller bursa6- reflexion of the synovial membrane15- infrapatellar fat pad16- patella17- infrapatellar synovial fold18- alar folds19- infrapatellar bursa20- patellar ligament

Knee joint, intrinsic Ligaments, Menisci:

Ligaments:*Ant cruciate lig:Prevents backward sliding of femur, produces medial rotation,Locks the knee in extension

*Post cruciate lig: prevents femur from forward sliding.

*Popliteus M.: Flexes the knee, unlocks the knee, and laterally rotates the femur on tibia.Meniscofemoral ligaments (ant and post)

*Tears of the Menisci:Longitudinal and transverseDuring partial flexion and lateral Rotation (mostly).Medial meniscus 20 times morethan the lateral one.

*Pathology: Unhappy TriadDuring skiing (caught-edge fall) In football (clipping)

Knee joint:Movements:Flexion and extension: (140o)Femur rolls and glides on menisci

Rotation: Femur and menisci move over tibia

Phases of knee extension:1- Initial phase: Rotation in suprameniscal compartment

2- intermediate phase: Femur glides forward in inframeniscal compartment 3- Terminal phase: (screwed home) medial rotation, tight collateral ligaments Obligatory terminal rotation of about 5o.

Flexion: during flexion, fibular collateral ligamentis completely relaxed as well as medial collateralligament and both ACL and PCL are taut.

Pathology:*Drawer phenomenon*Wobbly joint

1-malleolar mortise2-joint capsule3-Deltoid lig:4-tibionavicular part5-tibiocalcaneal part6-tibiotalar part8-navicular bone9-sustentaculum tali10-ant. Talofibular lig11-calcaneofibular lig12-ant. Tibiofibular lig13- Talus14- Calcaneus15- Cuboid16- Biforcate lig17- 2nd matatarsalRed: Chopart’s joint line(transverse tarsal joint)Blue: Lisfranc’s joint line18-plantar calca-cuboid lig19-long plantar lig20-medial cuneiform21-intermediate cuneiform22-lateral cuneiform23-medial tubercle of post process of talus24-plantar calc-navicul lig

*Ankle (talocrural) Joint: Articular surfaces: Tibia, fibula, talus

Type: Hinge jointMonoaxial: transverse axisfrom medial malleolus to lateral malleolus.Movements:plantar flexion 25o and dorsiflexion 35o.

*Ligaments:Deltoid lig (3,4,5,6) (crossed by TP and FDL)posterior andanterior Talofibular (10) Calcaneofibular lig (11)

*Sprains: mostly Inversion sprains

*Tretment: RICE

11

16

1- subtalar joint2- talocalcaneonavicular J.3-Talus4-Calcaneus5-lat talocalcaneal lig6-Navicular 7-plantar calcaneonavicular lig (Spring ligament)8-tense biforcate lig9-Cuboid10-interosseuos talo-calc lig11-calcaneocuboid joint12-dorsal calc-cuboid lig13-dorsal cuboido-navicul lig14-talonavicular lig15-dorsal tarso-metatars lig16-dorsal metatarsal ligs17-long plantar lig18-plantar metatarsal ligs19-tendon Peroneus longus20-tendon tibialis ant21-tendon tibialis post22-tedon peroneus brevis23-plantar calc-cuboid lig24-plantar cuboideo-navic ligament.

Subtalar and Talocalcaneonavicular J.

*Subtalar Joint:(posterior)Articular surfaces:Talus (the post calcaneal)Calcaneus

Ligaments:Med and lat talocalcanealAnd interosseous T-C.

*TalocalcaneonavicularJoint (anterior):Articular surfacse:1-talus 2-calcaneus 3-navicular 4-plantar calcaneonavicular lig.

Type: Ball and SocketMovement: Rotation(inversion and eversion)

*Walking on slope mediatedby movements over Subtalar+Transverse tarsal joint:(talocalcaneonavicular and calcaneocuboid) joints

Movements of the foot,The axis of Henke(rotation occurs over this axis)Only look

Metatarsophalageal J.

Type:Ball and socket joints but,restricted mobility due to collateral ligaments.

Interphalangeal J.Type:Hinge joints

Ligaments of the foot:Not important

Longitudinal arches:

Plantar arches

Shapes of the foot:Arch pathology:

**Disorder of joints:Injuries:Sprains: when ligaments reinforcing a joint are stretched or torn, very painful. Complete rupture of the ligaments needs surgical repair or removal.Dislocation (luxation): when bones of the joint are forced out of alignmentSubluxation: partial or incomplete dislocation of the joint.Torn cartilage: mainly in the knee joint. Surgical repair and removal of the torn parts (loose body) through arthroscopic surgery. Autologous cartilage implantation: used to heal damaged joint cartilage.

Inflammatory and degenerative joint diseases:Bursitis and tendinitis: inflammation of the bursa or tendon.Housemaid’s knee: prepatellar bursitis Student’s elbow or Olecranon bursitis

Arthritis: inflammation or degeneration of the joints accompanied by pain, swelling and stiffness.

Rheumatoid arthritis: autoimmune disease, sever inflammation of the joints.Ankylosing spondylitis: kind of rheumatoid arthritis affecting sacroiliac joints and vertebrae (mainly in males).Osteoarthritis: degenerative condition involving articular cartilages mainly in weight-bearing joints.Gouty arthritis: Inflammation caused by high blood levels of uric acid and deposition of urate salts in the synovial membranes.Lyme disease: arthritis caused by bacteria transmitted by tick bites.