Tibia, Fibula and Patella Flashcards
Tibia general
- Second longest, second strongest bone in the body
- Longer than the fibula
- Differences by sex: males are nearly vertical while females have the distal end located more medial (a little bow-legged)
- Inferior surface is called the tibial plafond
Proximal tibia
- Superior surface is called the tibial plateau
- Greatly enlarged
- Tibial plateau is oval shaped (wider side-to-side) and contains medial and lateral condyles (flattened)
- Central portion of condyles articulate with femoral condyles
- Medial and lateral menisci overly peripheral portions (outer portions) of the condyles
Medial condyle
- Larger, with larger articular surface
- Medial surface is roughened for attachment of the tibial (medial) collateral ligament
Non articular intercondylar ridge
- Located between condyles
- Not part of the articular surface of the knee joint
- Located between medial and lateral condyles
- Contains 3 structures
3 structures of the intercondylar ridge
- Anterior intercondylar fossa (contains 3 “anterior” structure attachments)
- Intercondylar eminence
- Posterior intercondylar fossa (contains 3 “posterior” structure attachments)
Hand trick to remember what is attached where
- Hold hands in two C’s
- The right hand is medial, left hand is lateral
- The fingers are posterior, thumbs are anterior
- The right hand (medial) is the “big C” and the left hand (lateral) is the “little C”
- Touch your fingers together (posterior)
- Hold your thumbs apart (anterior)
Order of attachments from posterior to anterior
- PCL
- Posterior horn of medial meniscus
- Posterior horn of lateral meniscus
- Anterior horn of lateral meniscus
- ACL
- Anterior horn of medial meniscus
Intercondylar eminence
- Located between the anterior and posterior fossas
- Consists of a bony ridge with 2 tubercles (medial and alteral intercondylar tubercles)
- Covered with articular cartilage that is continuous with the tibial condyles
Tibial tuberosity
- Triangular prominence of bone with the apex directed inferiorly
- Attachment site of the patellar ligament is a continuation of quadratus femoris tendon
- Palpable
Fibular facet
Facet closest to the face (the inferior articulation is considered fibular notch)
- Oval shaped
- Posterolateral depression on the lateral tibial condyle
- Proximal articulation to the tibia and fibula (tib-fib joint)
3 borders of the shaft of the tibial
- Anterior
- Medial
- Lateral
Anterior border of shaft of tibia
- “Shin” is subcutaneous and palpable
- Rotates medially to become the anterior border of medial malleolus (starts at tibial tuberosity)
- This is the attachment site for crural fascia (deep fascia of the leg)
Medial border of shaft of tibia
- Extends from below the medial condyle and rotates medially to become the posterior border of the medial malleolus
- This is the attachment site for 4 structures
4 structures that attach to medial border of tibia
- Medial collateral ligament
- Popliteus muscle
- Soleus muscle
- Flexor digitorum longus
Lateral border of shaft of tibia
- AKA “interosseous crest”
- Extends from articular fibular facet, divides into anterior and posterior borders of fibular notch inferiorly
- Attachment site for posterior (inferior) tibiofibular ligament
3 surfaces of shaft of tibia
- Medial
- Lateral
- Posterior
Medial surface of shaft of tibia
- Smooth, convex
- Located between anterior and medial borders
- 3 muscles attach superiorly and have a common aponeurosis (pes anserinus)
- Pes anserinus = SGT (say grace before tea)
- S = sartorius
- G = gracilis
- T = semitendinosus
- Also, there is a roughened area superiorly for attachment of the tibial collateral ligament
- Inferiorly, the medial surface is subcutaneous and the crural fascial attaches along the medial surface of teh tibial shaft
Lateral surface of shaft of tibia
- Narrow surface with just one muscle attachment - tibialis anterior
- Tibialis anterior attaches on the upper 1/2 to 2/3
- Lateral surface is grooved by this muscle origin
- There are 4 tendons which cover the distal portion (medial to lateral)
- These include tibialis anterior, extensor hallucis longus, extensor digitorum longus, peroneus tertius
Posterior surface of shaft of tibia
- The soleal line is an oblique ridge from superolateral to inferomedial and is a partial origin of the soleus muscle
- The vertical line extends inferior from the soleal line
Muscle attachments in relation to vertical line on posterior surface of shaft of tibia
Lateral to vertical line
- Tibialis posterior (partial origin)
- Nutrient foramen
Medial to vertical line
- Flexor digitorum longus
Distal portion of posterior surface of shaft of tibia
- Smooth
- Covered by tendons (flexor digitorum longus, tibialis posterior, flexor hallucis longus)
NOTE: FDL is medial, TP is deep, FHL is lateral
Position of tendons at distal portion of tibial
REMEMBER
- At the distal portion of the psoterior surface of the tibia, the FDL and FHL are in opposite positions of what you would think
- Hallucis is more lateral, digitorum is more medial
- They cross at the heel
(anterior) Tom, Dick, Very Nervous Harry (posterior)
Nutrient foramen of tibial
- Blood supply from a branch of the posterior tibial artery
- Located just distal to the soleal line and lateral to the vertical line
- Points directly away from the growing end of the tibia (which is the proximal end)
- LARGEST nutrient foramina
Distal tibia
- Larger than shaft, smaller than proximal part
- 5 surfaces: anterior, posterior, lateral, medial, inferior
Anterior distal tibia
- Continuous with the lateral surface of the shaft of the tibia
- Distal portion contains a transverse groove for attachment of the ankle joint capsule
- Smooth except for this attachment site
Posterior distal tibia
- Continuous with posterior surface of shaft
- Continuous with posterior aspect of medial malleolus
- Grooves for 2 tendons are present here: tibialis posterior (deep to FDL) and flexor hallucis longus
Lateral distal tibia
- Fibular NOTCH (not facet) for articulation with fibula
- Attachment of 2 ligaments along margins (anterior tibiofibular ligament and posterior tibiofibular ligament)
Medial surface of distal tibia
Continuous with medial malleolus
Inferior surface of tibia
- AKA tibial plafond
- Quadrilateral shaped
- Wider anteriorly
- Concave anteroposteriorly
- Convex side to side
Medial malleolus
- Pyramidal shaped
- Extends inferiorly beyond rest of tibia
- Lateral surface articulates with talus
- Comma shaped facet for talar articulation
- Lateral surface is continuous superiorly with the tibial plafond
- Medial surface is subcutaneously palpable
Inferior surface of medial malleolus
- Inferior surface has 2 slight elevations (“hills”)
- These are the anterior and posterior colliculi
- The deltoid ligament attaches to both of these colliculi as well as the intercollicular sulcus, anterior border of medial malleolus, posterior border of medial malleolus
Posterior border of medial malleolus
- More pronounced than the anterior border
- Contains a malleoluar sulcus, which is a groove along the posterior
- The malleolar sulcus is the location of 2 tendons - tibialis posterior and flexor digitorum longus
- Flexor retinaculum attaches near the malleolar sulcus
Tibial arterial supply
- Genicular anastomosis (proximal end)
- Malleolar anastomosis (distal end)
- Anterior tibial artery (periosteum shaft)
- Nutrient artery
Nutrient artery
- Branch of the posterior tibial artery
- Foramen of nutrient artery is the LARGEST of all long bones
Tibial ossification centers
- Primary ossification center (#1)
- 1st secondary ossification center (#2)
- 2nd secondary ossification center (#3)
Primary ossification center of tibia
- Located on the shaft
- Appears at the 7th week in utero
- Fuses at puberty
1st secondary ossification center of tibia
- Located at proximal end
- Appears at birth
- Fuses at 16 to 18 years
2nd secondary ossification center of tibia
- Located at distal end
- Appears at 1 year
- Fuses at 15 to 17 years
Accessory ossification center in tibia
- At times, an accessory ossification center is present and located at either the medial malleolus or the tibial tuberosity
General fibula
- Articulates with the tibia and talus (NOT femur)
- Non-weight bearing bone anatomically
- Functions as a site for muscle attachment
Head of fibula
- Irregular quadrate shape (somewhat)
- Apex or “styloid process” is the superior projection from posterolateral portion of the head
2 structures which attach to styloid process of fibula
- Biceps femoris tendon
- Lateral collateral ligament of the knee joint
3 structures which attach to anterior aspect of fibula
- Peroneus longus
- Extensor digitorum longus
- Anterior ligament of head of fibula
2 structures which attach to posterior aspect of fibula
- Soleus muscle
- Posterior ligament of head of fibula
Neck of fibula
- Constricted region, just distal to inferior fibular head
- Common peroneal nerve courses around neck of fibula
- This is often the site of peroneal nerve damage
Shaft of fibula has 4 surfaces
- Anterior
- Medial
- Lateral
- Posterior
Anterior surface of shaft of fibula
- Flat, narrow surface
- 3 muscles originate here: extensor hallucis longus, extensor digitorum longus, peroneus tertius
NOTE: this is all the anterior compartment muscles, except the tibialis anterior, which attaches superolaterally on the tibia and interosseous membrane
Medial surface of shaft of fibula
- Partial origin of tibialis posterior
NOTE: medial surface of fibula points POSTERIORLY and is located behind the interosseous membrane
Lateral surface of shaft of fibula
Origin of 2 muscles
- Peroneus brevis
- Peroneus longus
These are BOTH lateral compartment muscles
Posterior surface of shaft of fibula
- Superiorly the soleus takes partial origin
- Contains a nutreint foramen (branch of peroneal artery)
- Midway: origin of flexor hallucis longus
- Inferiorly: interosseous ligament attachment
Another name for the posteromedial border
The posteromedial border of the fibula is also known as the oblique border because it runs obliquely to join the anteromedial border (hence the psoterior surface attachment of interosseous ligament)
4 borders of fibular shaft
- Anterolateral
- Anteromedial
- Posterolateral
- Posteromedial (oblique)
Intermuscular septa
- Deep fascia of the leg (crural fascia) forms 2 intermuscular septa which attach to the fibular shaft
- Anterolateral border: separates extensor muscles from lateral muscles
- Posterolateral border: separates lateral muscles from flexors
- Tibia: separates flexors from extensors
Anteromedial border of the fibula
AKA “interosseous crest”
- Interosseous crest attaches here
Posteromedial border of the fibula
- AKA “oblique ridge”
- Courses obliquely and blends inferiorly with the interosseous crest
Lateral malleolus
- Major feature of distal fibual
- Base of malleolus is continuous with the shaft
- Apex of malleolus is pointed distally
Medial surface of lateral malleolus
- Triangular shaped facet articulates with talus
- Lateral malleolar fossa is located posterior to the facet
2 structures attach to lateral malleolar fossa
- Posterior tibiofibular ligament (superiorly)
- Posterior talofibular ligament (inferiorly)
Lateral surface of lateral malleolus
- Subcutaneous (easily palpable)
Anterior border of lateral malleolus
Attachment site for 3 ligaments
- Anterior tibiofibular ligament
- Anterior talofibular ligament
- Calcaneofibular ligament
NOTE: calcaneofibular ligament also attaches to the apex of the lateral malleolus
- There is a small inferior tubercle on the anterior border for this attachment
Posterior border of lateral malleolus
- Shallow sulcus (groove) where two tendons pass through
- Peroneus longus tendon
- Peroneus brevis tendon
Fibular ossification centers
- Primary ossification center (#1)
- 1st secondary ossification center (#2)
- 2nd secondary ossification center (#3)
Primary ossification center
- Located at the shaft
- Appears at week 8 in utero
- Fuses at puberty
1st secondary ossification center
- Located at distal end (opposite of tibia)
- Appears at 1 year
- Fuses at 15-17 years
2nd secondary ossification center
- Located at proximal end
- Appears at 3-4 years
- Fuses at 17-19 years
NOTE: the 2nd secondary ossification center is the last to form and also the last to close - this is ATYPICAL - usually the 1st secondary ossification center is the last to close (fuse)
Patella
- Sesamoid bone within the tendon of quadriceps femoris
- Largest sesamoid bone in the body
- Articulates with femur as part of the knee joint
- Triangular shaped with the apex directed inferiorly
Boarders of the patella
- Superior
- Medial
- Lateral
Superior border of the patella
- Base of triangular bone, thickest border
- 3 muscles attach here: rectus femoris, vastus intermedius, vastus lateralis (lateral superior portion)
Medial border of the patella
- Vastus medialis attaches here
lateral border of the patella
- Vastus lateralis attaches here (as well as the superior border)
Surfaces of the patella
- Anterior
- Posterior
Anterior surface of the patella
- Convex shape with small nutrient foramina
- Contains longitudinal stria for quadratus tendon attachment
Posterior surface of the patella
- Articulates with femur and is part of the knee joint
- 2 regions: upper 4/5 and lower 1/5
Upper 4/5 of posterior surface of patella
- Smooth, oval shaped surface
- Contains vertical ridge which separates the two patellar facets and articulates with the intercondylar groove of the femur
- 2 patellar facets are located here
Patellar facets of upper 4/5 of posterior surface of patella
- Covered by hyaline cartilage
- Articulate with femur as part of knee joint
- Lateral facet is LARGER and DEEPER
- Lateral facet is also more concave
Lower 1/5 of posterior surface of patella
- Roughened attachment site for patellar ligament
- Contains a nutrient foramen
Arterial supply to the patella
- Branches of the genicular arteries supplying the quadriceps tendon
Patellar ossification
- Variable number of centers
- Appears from 3-6 years with additional centers appearing later in childhood
- Patella is usually completely ossified around the time of puberty
