Upper Extremity Joints: Anatomy

Juncturae Membri Superioris (Upper Extremity Joints) Overview

• Joints of the upper extremity are divided into joints of the shoulder girdle and joints of the free upper extremity.
• The shoulder girdle joints include the sternoclavicular and acromioclavicular joints.
• The free upper extremity joints include the shoulder, elbow, joints between forearm bones, and hand joints.

Juncturae Cinguli Pectorales (Shoulder Girdle Joints)

• This category includes the sternoclavicular and acromioclavicular joints.

Art. Sternoclavicularis (Sternoclavicular Joint)

• This is a ball-and-socket joint (art. spheroidea).
• It articulates via the incisura clavicularis of the manubrium sterni and the facies articularis sternalis of the clavicle.
• It is surrounded by a capsula articularis.
• A discus intra-articularis is an accessory element.
• The edges of the disc are fused with the articulation capsule.
• The disc separates the cavity into two parts.

Accessory Ligaments of the Sternoclavicular Joint

• Lig. Sterno-claviculare anterius runs from the manubrium sterni to the clavicle.
• Lig. Sterno-claviculare posterius also runs from the manubrium sterni to the clavicle.
• Lig. Costo-claviculare goes from the 1st rib to the clavicle.
• Lig. Inter-claviculare is located between the clavicles, above the jugular notch.

Movements of the Sternoclavicular Joint

• Movements include elevation (elevatio), depression (depressio), and forward/backward movements (flexio, extensio).
• Rotation (rotatio) and circumduction (circumductio) are also possible.

Art. Acromioclavicularis (Acromioclavicular Joint)

• This is a gliding joint (art.plana).
• It articulates with the facies articularis clavicularis of the acromion and the facies articularis acromialis of the clavicle.
• It is surrounded by a capsula articularis.
• A discus articularis is an accessory element.

Ligaments of the Acromioclavicular Joint

• Lig. Acromio-claviculare runs from the acromion to the clavicle and strengthens the joint from above.
• Lig. Coraco-claviculare goes from the proc. coracoideus to the clavicle.
• It strengthens the joint from below.
• Movement is limited to little gliding actions.

Syndesmoses Cinguli Pectoralis (Scapular Ligaments)

• Lig. Coraco-acromiale runs between the processes.
• It is the most powerful ligament of the scapula.
• It forms a dome/vault over the shoulder joint (art. humeri).
• Lig. transversum scapulae superius runs above the suprascapular notch and forms an opening for the nerve.

Juncturae Membri Superioris Libteri (Joints of the free upper extremity)

• The joints of the free upper extremity include the shoulder joint, elbow joint, joints between forearm bones, and the hand joints.

Art. Humeri (Shoulder Joint)

• It is a ball-and-socket joint (art. spheroidea).
• It articulates with the caput humeri (head of the humerus) and the cavitas glenoidalis scapulae (glenoid cavity of the scapula).
• An accessory element is the labrum glenoidale.
• It is surrounded by the capsula articularis.

Labrum Glenoidale

• A cartilaginous glenoid lip, attached to the outer edge of the glenoid cavity, increasing the depth of the cavity.

Capsula Articularis

• A free, weakly connected capsule that attaches to the outer edge of the glenoid lip.
• The capsule embraces the humeral head and terminates on the collum anatomicum humeri.
• The Tendo m. biceps brachii runs in sulcus intertubercularis across the joint, and the capsule forms a synovial sheath (vagina synovialis) for it.

Ligaments of the Art. Humeri

• The ligaments include lig. coraco-humerale.
• S: proc. coracoideus scapulae, E: tuberculum majus humeri.
• Also included is Lig. coraco-acromiale

Movements of the Art. Humeri

• The movements possible here are flexio/extensio brachii on the frontal axis
• It can also perform abductio/adductio brachii on the sagittal plane
• Rotatio interna et externa brachii - vertical
• And circumductio brachii - all axes

Art. Cubiti (Elbow Joint)

• This is a composite joint (art. composita).
• It includes the art. humero-ulnaris (ginglymus), art. humero-radialis (art. spheroidea), and art. radio-ulnaris proximalis (art. trochoidea).
• The art. humero-ulnaris involves the trochlea humeri and incisura trochlearis ulnae.
• The art. humero-radialis involves the capitulum humeri and fovea capitis radii.
• The art. radio-ulnaris proximalis involves the circumferentia articularis radii and incisura radialis ulnae.
• The capusa articularis surrounds it.
• Anteriorly: Above fossa radialis and fossa coronoidea
• Laterally: under epicondyles
• Posteriorly: above fossa olecranii
• Ulna: along incisura trochlearis
• Radius: to the collum radii
• The movements are flexio, extensio antebrachii – frontal axis

Ligaments of Art. Cubiti

• E.L.H and E.M.H
• The ligaments are lig. collaterale ulnare, lig. collaterale radiale, and lig. anulare radii.
• The lig. collaterale ulnare is from E.M.H to incisurae trochlearis ulnae medial dide
• Lig. collaterale radiale is from E.L.H downward, separates into the 2 bands, embrace caput radii from anterior & posterior sides, fuses with lig.anulare and ends at incisurae radialis ulnae
• The lig. anulare radii embraces caput radii and ends on incisurae radialis ulnae ant&post sides

Joints Between Forearm Bones

• Includes a fibrous joint, the membrana interossea antebrachii, found between the margo interosseus radii and ulnae.
• Also includes the art. radioulnaris proximalis and art. radioulnaris distalis.

Art. Radioulnaris Proximalis

• Incisura radialis ulnae joins with the circumferentia articularis radii.
• It is surrounded by capsula articularis.

Art. Radioulnaris Distalis

• The incisura ulnaris radii connects with the circumferentia articularis ulnae.
• The ligaments are the capsula articularis and accessory a discus articularis

Movements at 3 Joints Simultaneously

• Pronatio (rotatio interna) - Rotating radius crosses ulna and hand turns with its dorsal surface upward.
• Supinatio (rotatio externa) antebrachii - The forearm bones are parallel and the hand turns with the palm facing upward.
• Pronatio and supinatio use art. radioulnaris proximalis, art. radioulnaris distalis, and art. humeroradialis.

Artt. Manus (Hand Joints)

• These joints are the radiocarpal, intercarpal, carpometacarpal, intermetacarpal, metacarpophalan- geal, and interphalangeal joints.

Art. Radiocarpalis (Wrist Joint)

• The facies articularis carpalis radii joins with a discus articularis
• Next there has to be another connection with these ossis scaphoidei, ossis lunati, ossis triquetri
• Capsula articularis surrounds it
• Discus articularis has a triangular shape, apex to the proc.styloideus ulnae, basis to the incisurae ulnaris radii
• Other ligamnets to describe include the liagaments relating to the ulna and also the Radius

Ligaments of the Carpus

• The ligaments are lig. collaterale carpi radiale, lig. collaterale carpi ulnare, as well as the following Radio-Carpal Ligaments Palmar L. Dorsal L.
• Movements possible here ae with a long list of terms and conditions

Os Scaphoideum

• Os scaphoideum and os trapezium forms an eminencia at the radial side of the hand, but os hamatum and os pisiforme – at the ulnar side of the hand
• All that then for the Canalis Carpi which we will have to look at another time

Artt. Carpi

• In general the Ficies for this section are with a long list of terms and conditions, so make sure to make extra notes for these

Art. Ossis Pisiformis

• FACIES ARTICULARIS ossis pisiformis FACIES ARTICULARIS ossis triquetri
• As well as the capsules

Art Mediocarpal

• FACIES ARTICULARIS ossis scaphoidei, ossis lunati, ossis triquetri and also the oiss list relating to capii and the
• Ligamnets for these are intercarpalia with the interoosseua and palmarua as well as dorsalia
• There is very little movemnet available

Art. Radiocarpalis continued..

• ligaments from that line etc

Art. Carpo-metacarpales

• FACIES ARTICULARIS ossiumcarpalium FACIES ARTICULARES basium ossium metacarpalium - that is where it makes the difference
• The surronding ligaments are the capsulae as well as dorsal ligaments

Art carpo-metacarpalis pollicis

• There is another Ficies situation happening here as well metacarpalis primi
• And there are list of movements possible for both abduction positions, the circumduction can be a killer

Art. Metacarpo-phalangera

• FACIES ARTICULARIS capitis ossis metacarpalis and the same in the basis position
• Surronding these is a capsula articularis that surrounds them

Movements of Metacarpo-phalangera

• Metacarpo-phalangera are the ones that you have heard most of- Flexor, Extension and then all the
• Surronding them are all there collaterals and Palmare, all that has to be kept in check

Art Interphalangera

• The Ficies come of what your expect there- same here like before, and the ligaments are similar as well.
• All are surroundy by Articularae , good look get these down.