Regional anatomy

Two regions:

1. Pre-axial region = Radial side of the limb (lateral)

2. Post-axial region = ulna side (medial)

3. Ventral axial line - separates tissues of arm and forarm into embryological regions of limb

Shoulder > arm > forarm > wrist > hand

Joints - Sternoclavicular joint (Girdle), Gleno-humeral Joint (Girdle), Elbow joint, Wrist Joints, Joints of the hand

Two musculo-fascial compartments

• each has its own muscles, blood supply, venous drain, nerve innervation and lymphatics

The groove is between anterior and middle scalene muscle

• the roots of brachial plexus lie in relation to the scalene muscles

• Nerve root value of brachial plexus are C5 to T1

• Clinical significance is to be able to temporarily block all sensation arising from the upper limb by anaesthetising roots of brachial plexus.

  • Needle inserted halfway between lateral border of sternocleidomastoid muscle and anterior border of trapezius muscle.

Sternoclavicular joint

• Formed by articulation of medial aspect of clavicle with manubrium of sternum

• Classified as plane style synovial joint and has fibrocartilage joint disc

• One of the 4 joints that compose the shoulder complex (pectoral girdle)

Clavicle extends from manubrium of the sternum to acromion

• Its sternal (or medial) end is triangular & articulates with the Sternum at the Sternoclavicular joint

• Its acromial (or lateral) end is flattened & articulates with the Acromion of the Scapula at the acromioclavicular joint

Sternocleidomastoid muscle pulls the medial 2/3 of the clavicle upwards (convex anteriorly) while the trapezius muslce pulls the lateral piece medially (concave anteriorly) .

Axilla is the anatomical space of the armpit (under where arm connects shoulder). It is a pyramid shape, has 4 sides, apex and base.

Axillary sheath - Brachial plexus, axillary artery, axillary vein

Axillary lymph nodes

• Part of axial skeleton

• Acts as a site of attachment of lower limbs > enables locomotion

• Supports vertebral column, spinal cord and attendant CSF

• Suppors upright posture when standing

• In upright position, supports carrying of weight of head, neck, thorax, upper limbs and trunk

• Site for pregnancy

• Houses important viscera - pelvic viscera proper, viscera of abdomen.

PID, UTI, pregnancy, urinary / faecal incontinence, childbirth

• shared - bones

• Female has wider (rounder) pelvic brim, male ha heart shaped.

• Male has acute (triangular) pubic arch, female is slightly rounded (pic)

Urinary system

Lower GI tract

Reproductive system

Parturition (female)

Pelvic floor (pelvic diaphragm)

Musculature of proximal lower limb

• Greater Pelvis (or False Pelvis)

• Pelvic Brim

  • Also known as the Pelvic Inlet

  • True Pelvis (vs Lesser Pelvis)

• Outlet

  • Pelvic Floor

  • Interaction between the Pelvic Floor & Viscera of

    the Urinary Tract & Reproductive Tract

Formed of 3 main bones;

• 2 pelvic bones - left and right, joined anteriorly by pubic symphysis

• 1 sacrum & coccyx - form middle of the posterior border

Direct landmarks

• Supracristal plan (top black line) - L4/L5, safe site for LP

• Anterior superior iliac spine - site for inguinal ligament attachment, used in measurement of limb length

• Anterior inferior iliac spine (top dot)

• posterior superior iliac spine (bottom dot)

• pubic crest (bottom line) - site for suprapubic puncture of urinary bladder

Indirect landmarks

• Greater trochanter - hip joint

Composed of union of 3 bones - the bones unite to form the acetabulum.

They unite by ossification of tri-radiate cartilage of acetabulum.

• Ilium (forms most of the superior part)

• Ischium (forms most of the Posterior portion)

• Pubis (forms most of the anterior portion)

• forms the lowermost aspect of vertebral column

• Fomed from fusion of 5 sacral bones (S1 to S5)

• Form the sacral curvatures of the vertebral column

• Articulates with hip bones via 2 articular surfaces

• The holes are sacral foramen where spinal nerves comes through

• Forms the final segment of the vertebral column

• Formed by process of secondary neurilation

• Composed from the union of 4 coccygeal bones

• Greater (false) pelvis

• Lesse (true) pelvis

• anterior wall

• posterior wall

• 2 lateral walls (L + R)

• Inferior wall (pelvic floor)

• its the continuation of the pelvic body wall

• Major site of attachments of pelvic organs - uterus

• Site of attachments of muscles that move the lower limb - esp thigh

• important anatomical features includes - pelvic bone, ligaments of pelvis, msucles, peritoneum, fascia, anatomical spaces

• Hip bone

• Ligaments - Sacrospinous and sacrotuberous

• Obturator membrane

• anatomical spaces - obtrurator foramen (anteriorly), greater sciatic foramen, lesser sciatic foraemen (posteriorly)

There are a number of palpable bony landmarks of significance

• Iliac crest

• Anterior superior iliac spine (ASIS)

• Pubic tubercle

• Greater Trochanter

• Medial / inferior edge of the patella

• Tibial tuberosity

• Medial malleolus (tibia)

• Lateral malleolus (fibula)

• Navicular

Iliac crest left and right

• they mark the highest anatomical points of LL

• Imaginary line between the two iliac crest > anatomical plan known as supracristal plane (Tuffier’s line)

• Horizonal plan between R and L iliac crest

• Occurs around level of L4 (L3/4 intervertebral disc)

• landmark for:

  • Bifurcation of descending aorta into left and right common iliac arteries

  • safe area for LP, epidural anaesthesia and determining site for aspiration of bone marrow.

Anterior superior iliac spine (ASIS)

• prominence of the ilium - located onthe superior, anterior margin of the pelvis.

McBurney’s point

• On the right side of the abdomen, 1/3 of the distance from ASIS to the umbilicus - corresponds to the location of appendix.

• Used to assess palpation in suspected appendicitis and used for surgery such as appendicetomy

Inguinal ligament is a fibrous inferior border of the anterior abdominal wall. It attach to ASIS (supero-laterally) and pubic tubercle (infero-medially).

• Defines the border between abdomen and lower limb

• anatomical structures that pass (deep):

  • Femoral canal

  • femoral sheath - fascia which encloses femoral artery and veins

  • femoral nerve/artery /vein (lateral to medial)

  • lateral cutaneous nerve of the thigh

  • psoas major/ iliacus / pectineus muscles (floor of the femoral triangle)

  • lymphatics.

Inguinal canal

• runs directly superior and parallel to the inguinal ligament = runs inferior and medial through inferior part of abdominal wall.

• Canal starts at the deep inguinal ring and ends at the superficial inguinal ring.

• Structures that pass through:

  • Male - spermatic cord and testicular artery

  • female - round ligament of the uterus

  • both - ilio-inguinal nerve and genital branch of genitofemoral nerve

Lateral cutaneous nerve of the thigh pass deep into the inguinal ligament. It can be compressed by inguinal ligament > painful numbness of the upper part of the thigh

Femoral hernia

• herinated peritonieal sac protrude through fermoral ring > femoral canal

• This is because th femoral sheath is only closed by extraperitoneal tissue > site of weakness

Inguinal hernia - can be direct or indirect

• Direct - protrude through posterior wall of the inguinal canal

• Indirect - protrude through deep inguinal ring

• It is a lateral bony prominence of LL

• Detects ant changes in direction of the neck of femur relative to the shaft

• indirect landmark for position of the hip joint, capsule and extracapsular ligaments of hip joint.

Most hip dislocations are posterior (90%). This is due to the posterior (ischiofemoral) ligament being the weakest of the 3 ligaments of the joint.

The clinical presentation of a posterior hip dislocation includes:

• Shortened appearance of the affected lower limb

• Flexed position and Internal rotation of limb

Can occur as a result of motor vehicle collision where the hip joint is flexed

Medial malleolus of tibia

lateral malleolus of fibula

• The greater saphenous vein ascends anterior to medial malleoulus

• posterior tibial pulse of posterior tibial artery palpable in tarsal tunnel. it runs posteriorly and inferiorly to medial malleolus.

Examination:

• Patient lie down supine on their back then elevate the leg straight individually.

• Aims to stretch the sciatic nerve directly

Indication:

• Sciatica (lumbar rediculopathy) - spinal roots of sciatic nerve are damaged or injured

• Lumbar slipped disc or herniation

• Inflammed meninges of the spinal cord (meningism)

Tibial tuberosity - inferior border of the patella

• between these bony landmark is where patella tendon is located.

• strike of the tendon > knee jerk reflex

‘Apparent’ = one limb appears shorter than other, not necessarily short

• Posterior dislocation of hip joint in ‘shorter’ limb.

• Congenital cause of hip dislocation in ‘shorter’ limb.

• Hip tilting, for example due to scoliosis.

‘True’ = The limb is actually shorter in distance between ASIS and medial malleolus

• Congenitally shorter lower limb compared to the other limb.

• Fracture of one or more of the long bones of the shorter limb, leading to overlap in the bone fragments.

• Skeletal growth disorders.

• Scoliosis.

True limb length

• Measure the distance of the right and left limbs between anterior superior iliac spine (proximally) and medial malleolus of tibia (distally)

• If the length between R + L not same = true limb length discrepancy

Apparent limb length

• Measures the distance of R and L between umbilicus (proximally) and medial malleolus (distally)

• If the length between R+L not same = aparent limb length discrepancy