knee and hip

Question 1

stability

Answer 1

Body ‘designed’ to be efficient
Centre of gravity and soft tissue anatomy “locks”Joints on standing
During walking, combined movements (particularlypelvis) Minimises changes in C.o.G to reduce energyrequired to move
Pathological/biomechanical changes lead toextra/abnormal stresses

Question 2

musculature/connective tissues

Answer 2

Strength, stability, and movement
Flexion/extension
Abduction/adduction
Rotation
Divided into compartments in leg(ANTERIOR/LATERAL/POSTERIOR) separated bybones and fibrous tissue (fascia)

Question 3

nervous supply

Answer 3

Motor and sensory nerves arise from thelumbar and sacral regions; L1-S3
Innervate the lower limbs in specific regions (dermatomes/myotomes)
Important in clinical assessment and forconsideration in trauma

Question 4

the knee description

Answer 4

Largest joint in the body
Bony anatomy relies a lot on soft tissues forstrength/stability
Prone to trauma due to extrinsic position
Injuries Common in teenage/adult life insports/RTC’s
Arthritis / degenerative conditions common

Question 5

knee joint

Answer 5

Synovial bicondylar joint
Wide range of flexion/extension
Weight-bearing joint
Most force through medial joint
Can be altered by altered gait/pathology:
Genu varus
Genu valgus

Question 6

the knee on standing

Answer 6

Designed to ‘lock’ on extension
Improves efficiency by reducing muscle fatigue
Enabled by:
Flattened articular surfaces of distal femur
C.o.g anterior to knee, pushes it back
Femur is rotated medially which tightens ligaments
Flexion is initiated by popliteus muscle whichlaterally rotates femur and releases locking

Question 7

the knee bones

Answer 7

4 bones:
Femur
Tibia
Fibula
Patella
Synovial joint, 2 articulations (3compartments):
Femoro-tibial (medial / lateral)
Patello-femoral
Proximal tibio-fibular join

Question 8

distal femur

Answer 8

Formed predominantly by two roundedcondyles
Two smaller epicondyles provide attachmentfor collateral ligaments
Condyles separated posteriorly byintercondylar fossa; attachment for cruciateligaments
Anteriorly they form a v-shape for articulationwith the patella

Question 9

distal femur description

Answer 9

covered by hyaline cartilage
Condyles flattened on distal end
More rounded posteriorly
More stable when extended

Question 10

patella description

Answer 10

Sesamoid bone in quadriceps femoris tendon
Improves mechanical efficiency by acting as a
Apex inferiorly, flatter superiorly Posterior facets
Prone to medial/lateral dislocation

Question 11

proximal tibia description

Answer 11

Flattened and enlarged medial and lateral condylesfor weight-bearing and distribution
Separated by raised pair of intercondylar/tibialspines running anterior/posterior
Attachment site for cruciate ligaments/meniscus
Combined to form tibial plateau

Question 12

proximal tibia

Answer 12

Medial tibial condyle larger and stronger
Slightly concave centrally to articulate with femoralcondyles
Flattened depression on postero-lateral condyle forfibula head
Tibial tuberosity; attachment for patellaligament/tendon

Question 13

proximal fibula

Answer 13

Not part of knee joint, not weightbearing
Roughly triangular in cross-section
Head enlarged; attachment site Tibio-fibular joint is synovial; minimal movement

Question 14

OC distal femur

Answer 14

PRIMARY: Diaphysis/shaft (7th week in uTERO)
SECONDARY: distal EPIPHYSIS/FEMORALCONDYLES (~40th week in utero)
Fusion ~16-18 years

Question 15

OC patella

Answer 15

Primary: (3-6 years)
 Secondary (normal variant) only in somecases (bi-partite patella)
 Fully ossified during puberty

Question 16

OC proximal tibia

Answer 16

Primary: diaphysis/shaft (7th week in utero)
 Secondary:
 proximal epiphysis/tibial plateau (1 year)
 Tibial tuberosity apophysis (10-12 years)
 Fusion ~16-18 years

Question 17

OC proximal fibula

Answer 17

Primary: diaphysis/shaft (8th week in utero)
 Secondary: proximal epiphysis/head (3-4years)
 Fusion ~16-18 years

Question 18

menisci description

Answer 18

 C-shaped fibrocartilage rings on tibial condyles
 Attached anteriorly/posteriorly on tibial spines
 Increase surface area of articular surface of tibia to improvecongruence with femur
 Commonly injured/torn

Question 19

synovial membrane/capsule description

Answer 19

Forms intra-articular region of knee
 Attaches to tibial/femoral articular surfacesand menisci
 Passes anterior to cruciate ligaments
 Filled with synovial fluid to act as lubricant tomovement
 Bone surfaces covered by hyaline cartilage

Question 20

synovial membrane/capsule

Answer 20

Friction further reduced by:
 several extensions/recesses of capsule
 Presence of synovial bursae
 Infra-patella (Hoffa’s) fat pad
 Supra-patella bursa most significant in knee effusions
 Bursitis a common clinical presentation

Question 21

knee effusions

Answer 21

Caused by increase in fluid within the joint capsule:
 Blood
 Pus
 Synovial fluid
 Presents as oval opacity in supra-patella bursa on lateral
 Non-specific but In trauma it’s presence is suspicious for‘injury’
 Presence of fat and blood level indicates definite intra-articular fracture: lipohaemarthrosis

Question 22

fibrous joint capsule

Answer 22

 Encloses, Supports, and strengthens the joint
 Blends with medial meniscus and collateralligament
 Lateral structures less fixed and more mobile
 Connects medial/lateral patella to provide

Question 23

ligaments

Answer 23

Number of major and less significant ligaments providemuch of the knee’s strength and stability:
 Patella ligament( ?tendon)
 Collateral (medial/lateral)
 Cruciate (anterior/posterior)
 more likely to rupture in adults than bony injury (opposite in paediatrics)

Question 24

patella ligament

Answer 24

Continuation of quadriceps femoris tendon
 Connects apex of patella and tibial tuberosity
 Covered anteriorly/posteriorly to reduce friction:
 Superficial/deep infrapatellar bursa
 Hoffa’s fat pad

Question 25

collateral ligaments

Answer 25

Medial (tibial) collateral (MCL)
 Flat and broad
 Connected to fibrous capsule/meniscus
 Lateral (fibular) collateral (LCL):
 More like a rope
 Separate from capsule by bursa
 Prevent medial/lateral movement at knee joint
 Consider injury in side impact forces on

Question 26

cruciate ligaments

Answer 26

Cross’ in the intercondylar region
 Provide anterior/posterior stability preventing tibiamoving
 Anterior (ACL):
 Prevents anterior movement of tibia
 Lateral femoral condyle to anterior tibial spine
 Posterior (PCL):
 Prevents posterior movement of tibia
 Medial femoral condyle to posterior tibial spine
 Injury commonly associated with other structures;clinical examination and MRI

Question 27

neurovascular

Answer 27

Popliteal fossa:
 transition between region of thigh and leg
 Formed by space between muscles in posterior knee
 Neurovascular structure pass through this
 Branches from femoral/popliteal artery whichdivides into anterior/posterior tibial (forms ananastomosis)
 Sciatic nerve divides into tibial and commonfibular
 Small saphenous and tibial veins combine toform femoral vein