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The femur (thigh bone) is the longest and strongest bone in the human body.
It extends from the hip joint to the knee joint and transmits the weight of the body from the pelvis to the tibia.
Its length is about 1/4 of the body height.
It forms the upper segment of the lower limb skeleton and participates in:
Hip joint (proximally)
Knee joint (distally)
Upper End
Shaft
Lower End
Consists of:
Head –
Smooth, spherical structure forming 2/3 of a sphere.
Directed medially, upward, and slightly forward.
Covered with articular cartilage, except at the fovea capitis, where the ligament of head of femur attaches.
Neck –
Connects the head to the shaft.
Forms an angle of 125°–130° with the shaft (angle of inclination).
In newborns, this angle is about 150° and decreases with age.
Clinical correlation: Decrease in angle → coxa vara; Increase → coxa valga.
Greater Trochanter –
Large, quadrangular projection on the lateral side.
Gives attachment to:
Gluteus medius (lateral surface)
Gluteus minimus (anterior surface)
Piriformis (superior border)
Obturator internus and gemelli (medial surface)
Vastus lateralis (base)
Palpable on lateral aspect of thigh; used to locate hip joint level.
Lesser Trochanter –
Small, conical projection on the posteromedial surface.
Gives insertion to psoas major and iliacus muscles (as iliopsoas).
Intertrochanteric Line –
On anterior surface between the two trochanters.
Gives attachment to iliofemoral ligament (of hip joint capsule).
Intertrochanteric Crest –
On posterior surface between trochanters.
Has a rounded tubercle called quadrate tubercle for quadratus femoris muscle.
Long, cylindrical, and slightly bowed forward (anterior convexity).
Has three surfaces — anterior, medial, and lateral — separated by three borders — medial, lateral, and posterior.
Posterior border forms a prominent linea aspera, which divides above into:
Gluteal tuberosity (for gluteus maximus)
Pectineal line (for pectineus)
Spiral line (leading to lesser trochanter)
Linea aspera below divides into medial and lateral supracondylar lines.
Attachments along Linea Aspera
Lateral lip: Gluteus maximus, vastus lateralis, short head of biceps femoris.
Medial lip: Adductor longus, adductor magnus, vastus medialis.
Between lips: Adductor brevis and part of adductor magnus.
Expanded and articulates with the tibia and patella.
Has:
Two condyles (medial and lateral) – separated by intercondylar fossa (posteriorly) and patellar surface (anteriorly).
Patellar surface: Smooth anterior area for articulation with patella.
Medial condyle: Larger and projects lower; bears the adductor tubercle for insertion of adductor magnus.
Lateral condyle: Provides attachment to popliteus tendon.
Intercondylar fossa: Lodges cruciate ligaments of the knee.
Shaft – appears in the 7th week of intrauterine life (one of the earliest long bone centres).
| Part | Appearance | Fusion with Shaft |
|---|---|---|
| Lower end (distal epiphysis) | 9th month of intrauterine life | 18–20 years |
| Head | 1 year | 18 years |
| Greater trochanter | 4 years | 18 years |
| Lesser trochanter | 12–14 years | 18 years |
Note: The lower end ossification centre appears before birth and is used in determining fetal viability in forensic medicine.
Lesser trochanter → 18 years
Greater trochanter → 18 years
Head → 18 years
Lower end → 20 years
Complete fusion by about 20 years of age.
Neck of Femur
Common in elderly osteoporotic females.
Classified as intracapsular or extracapsular.
Intracapsular fracture → poor healing due to interruption of retinacular arteries (branches of medial circumflex femoral artery).
Leads to avascular necrosis of the femoral head.
Intertrochanteric Fracture
Between greater and lesser trochanters.
Extracapsular → heals well due to good blood supply.
Shaft Fracture
Common in young adults (motor accidents).
Causes shortening due to muscle pull:
Upper fragment → flexed, abducted, externally rotated (gluteus medius, iliopsoas).
Lower fragment → pulled upward by adductors.
Supracondylar Fracture
May injure popliteal artery, leading to ischemia and gangrene.
Coxa Vara – Decrease in neck-shaft angle (<120°).
Causes limp and limited abduction.
May be congenital or post-traumatic.
Coxa Valga – Increase in neck-shaft angle (>135°).
Causes unstable hip joint.
Slipped Capital Femoral Epiphysis – Displacement of femoral head epiphysis in adolescence.
Intramedullary nailing for shaft fractures – entry through greater trochanter.
Bone marrow biopsy rarely done in femur due to thick cortex.
Femoral head vascularity:
Mainly from medial circumflex femoral artery via retinacular vessels.
Damage leads to avascular necrosis.
Centre of ossification of lower end appears before birth — useful for determining fetal maturity.
Neck-shaft angle measurement helps in diagnosing deformities (coxa vara, valga).
Length of femur can be used to estimate body height using anthropometric formulas.
The patella is a large sesamoid bone developed within the tendon of quadriceps femoris.
It is the largest sesamoid bone in the body.
It is triangular, with:
Apex pointing downward.
Base directed upward.
Anterior surface convex and rough.
Posterior surface divided into articular and non-articular areas.
It articulates with the patellar surface of the femur to form the patellofemoral part of the knee joint.
To hold the bone in anatomical position:
The apex should point downward.
The base should be above.
The lateral articular surface is larger than the medial one — this helps in identifying the side.
Convex and rough for attachment of:
Fibres of quadriceps tendon (above).
Patellar retinacula (sides).
The lower part gives attachment to the ligamentum patellae, which connects the patella to the tibial tuberosity.
Upper three-fourths: Articular and smooth — covered with hyaline cartilage.
Divided into two facets by a vertical ridge:
Lateral facet: Larger and deeper; articulates with the lateral femoral condyle.
Medial facet: Smaller and shallower; articulates with the medial femoral condyle.
Lower one-fourth: Rough, non-articular area for attachment of ligamentum patellae.
Medial and lateral borders give attachment to medial and lateral patellar retinacula (expansions of vastus medialis and vastus lateralis).
The apex is the pointed inferior tip of the patella.
Gives attachment to ligamentum patellae.
Broad superior margin.
Gives attachment to the rectus femoris and vastus intermedius tendons.
Place the apex downwards and anterior surface facing forward.
The larger articular facet will be lateral → this determines the side.
Base: Tendon of quadriceps femoris.
Apex: Ligamentum patellae (to tibial tuberosity).
Medial border: Vastus medialis and medial patellar retinaculum.
Lateral border: Vastus lateralis and lateral patellar retinaculum.
Type: Sesamoid bone ossifying in tendon.
Centre of ossification:
Appears during the 3rd to 5th year of life.
Sometimes appears as two or more centres, which may not unite — forming a bipartite patella.
Fusion: Ossification is completed by puberty (around 14–16 years).
| Stage | Time of Appearance | Remarks |
|---|---|---|
| Primary centre | 3rd–5th year | Develops within quadriceps tendon |
| Accessory centres | May appear occasionally | Cause bipartite or tripartite patella |
| Complete ossification | By puberty | Around 14–16 years |
Transverse fractures are common due to direct blow or sudden quadriceps contraction.
The upper fragment is pulled upward by the quadriceps femoris; the lower fragment remains attached to ligamentum patellae.
Comminuted fractures (multiple fragments) occur from severe trauma.
Treatment: Tension-band wiring or open reduction fixation.
Occurs when ossification centres fail to unite.
Usually asymptomatic, discovered incidentally on X-ray.
Commonly located at the superolateral angle.
Must be differentiated from fracture (margins smooth, no pain).
Also called runner’s knee.
Softening and degeneration of articular cartilage on posterior surface of patella.
Causes anterior knee pain, especially while climbing stairs.
More common in adolescent females.
Usually lateral dislocation due to:
Shallow trochlear groove.
Lateral pull of vastus lateralis.
Weakness of vastus medialis oblique (VMO).
Predisposing factors: genu valgum, high patella (patella alta).
Tapping the ligamentum patellae causes extension of the leg via quadriceps contraction.
Tests the integrity of L2–L4 spinal segments and the femoral nerve.
Abnormal movement of patella during knee flexion/extension.
May cause crepitus or pain due to uneven cartilage wear.
Patellectomy: Surgical removal of patella, done rarely for comminuted fractures.
Results in loss of mechanical advantage of quadriceps → decreased extension strength.
The shape and height of patella used to assess patellar alta or baja (high-riding or low-riding patella).
Sunrise or skyline X-ray view shows alignment of patella in femoral trochlea.
The tibia (shin bone) is the medial and larger bone of the leg.
It is the second longest bone in the body, after the femur.
It bears the weight of the body from the femur and transmits it to the talus (ankle bone).
It articulates:
Above – with femur and fibula (at superior tibiofibular joint).
Below – with talus and fibula (at inferior tibiofibular joint).
The tibia has two ends and a shaft:
Upper end
Shaft
Lower end
Expanded for articulation with the femoral condyles and for the attachment of ligaments and muscles.
Medial and Lateral Condyles
Flattened articular surfaces separated by an intercondylar area.
Covered with hyaline cartilage for articulation with femoral condyles.
Medial condyle is larger and oval; lateral condyle is circular.
Intercondylar Area
Between condyles, divided into:
Anterior intercondylar area
Posterior intercondylar area
Gives attachment to anterior and posterior cruciate ligaments and menisci of the knee.
Intercondylar Eminence
A raised bony ridge between the articular surfaces.
Composed of:
Medial intercondylar tubercle
Lateral intercondylar tubercle
Prevents lateral displacement of femoral condyles.
Tibial Tuberosity
Prominent rough elevation below the condyles on anterior surface.
Upper smooth part – attachment of ligamentum patellae.
Lower rough part – for patellar retinacula.
Gerdy’s Tubercle
On lateral condyle, for insertion of iliotibial tract.
Articular Facet for Fibula
Located on posteroinferior aspect of lateral condyle, for head of fibula.
Triangular in cross-section, with three borders and three surfaces.
Anterior border (shin) – sharp and prominent; palpable under skin.
Medial border – smooth and rounded.
Interosseous border (lateral) – sharp ridge for attachment of interosseous membrane connecting tibia and fibula.
Medial surface – subcutaneous and easily palpable (skin over the shin).
Lateral surface – between anterior and interosseous borders; origin of tibialis anterior.
Posterior surface – marked by soleal line (oblique ridge) giving attachment to soleus; below it lies the nutrient foramen (directed downward).
Smaller and quadrangular; forms part of the ankle joint.
Medial Malleolus
Prominent downward projection on medial side; subcutaneous and palpable.
Lateral surface articulates with talus.
Medial surface gives attachment to deltoid ligament.
Fibular Notch
On lateral aspect for inferior tibiofibular articulation.
Inferior Articular Surface
Quadrilateral surface articulating with the superior surface of talus.
Groove for Tendons
Posterior aspect has grooves for tibialis posterior and flexor digitorum longus tendons.
Medial malleolus points downward and medially.
Tibial tuberosity is anterior.
Smooth articular surface for fibula lies laterally.
→ The bone belongs to the side of the medial malleolus.
| Structure | Muscles Attached |
|---|---|
| Upper anterior surface of tibia | Sartorius, gracilis, semitendinosus (Pes anserinus) |
| Upper lateral surface | Tibialis anterior |
| Soleal line (posterior surface) | Soleus |
| Below soleal line | Tibialis posterior, Flexor digitorum longus |
| Lateral surface (upper two-thirds) | Tibialis anterior |
| Lateral surface (lower third) | Extensor digitorum longus |
| Medial surface (subcutaneous) | No muscle attached |
| Centre | Time of Appearance | Fusion |
|---|---|---|
| Primary centre (shaft) | 7th week intrauterine life | — |
| Secondary centre for upper end | At birth | 20–22 years |
| Secondary centre for lower end | 1–2 years | 18–20 years |
| Secondary centre for tibial tuberosity | 12–14 years | 18 years (may fuse with upper epiphysis) |
Shaft – prenatal (7th week IU)
Upper end – at birth (contains an epiphysis with a large tibial tubercle)
Lower end – 1 to 2 years
Tibial tuberosity (accessory) – 12 to 14 years
→ All unite with shaft by 20–22 years.
Upper epiphyseal centre appears before birth → used in determining neonatal maturity.
The tibial tuberosity may ossify separately and later unite with the upper epiphysis.
Shaft fractures are common due to its subcutaneous position (especially lower third).
Usually open fractures because of poor soft-tissue cover.
Union is slow because of poor blood supply.
Upper end fractures may extend into knee joint (tibial plateau fractures), causing joint effusion and instability.
Lower end fractures (near medial malleolus) may involve the ankle joint, producing Pott’s fracture.
Occurs in adolescents due to avulsion or microfracture at the tibial tuberosity (site of patellar ligament attachment).
Caused by repetitive strain from quadriceps contraction.
Presents with localized pain and swelling over tibial tuberosity.
The subcutaneous anterior surface of tibia predisposes to compound fractures with risk of infection, delayed union, or osteomyelitis.
Seen in athletes and military recruits due to repeated microtrauma.
Typically in the lower third of shaft; visible on bone scan or MRI before X-ray.
The nutrient artery (from posterior tibial artery) enters the bone below the soleal line and runs downward — “to the elbow I go, from the knee I flee.”
Injury to this artery may delay healing.
Medial malleolus serves as attachment for the deltoid ligament, maintaining the medial arch of foot.
Malalignment (e.g., tibia vara or tibia valga) may alter gait and foot mechanics.
Tibial crest and medial surface used for bone graft harvesting.
Intraosseous infusion in emergencies (children) given in upper medial tibial surface below tibial tuberosity.
Length of tibia used for stature estimation in skeletal remains.
The fibula is the lateral and smaller bone of the leg.
It lies parallel to the tibia and is connected to it by an interosseous membrane.
It does not bear body weight; its main role is to provide muscle attachment and form the lateral wall of the leg.
The lower end forms the lateral malleolus, which takes part in forming the ankle joint.
Like other long bones, it has:
Upper end (Head)
Shaft
Lower end (Lateral malleolus)
Expanded into a head, with a rounded apex called the styloid process.
Articular facet on the upper surface of the head → articulates with the lateral condyle of tibia (superior tibiofibular joint).
Neck of fibula – constricted part below the head.
Common peroneal (fibular) nerve winds around it → vulnerable to injury.
Styloid process – projects upward from the head; gives attachment to:
Fibular collateral ligament (of knee joint).
Biceps femoris tendon.
Long, slender, and twisted.
Has three borders (anterior, posterior, interosseous) and three surfaces (medial, lateral, posterior).
Anterior border – begins below the anterior aspect of head and continues to anterior border of lateral malleolus.
Posterior border – extends from the back of head to the posterior border of lateral malleolus.
Interosseous border (medial) – for attachment of interosseous membrane.
Medial surface (anterior) – origin for extensor digitorum longus and extensor hallucis longus.
Lateral surface – origin for peroneus longus and peroneus brevis.
Posterior surface – has a vertical nutrient foramen directed upward;
Above: Soleus and Flexor hallucis longus.
Below: Peroneus longus.
Expanded to form the lateral malleolus, which extends lower and posterior to the medial malleolus of the tibia.
Medial surface – has a triangular articular facet for lateral surface of talus.
Anterior border – attachment to anterior talofibular ligament.
Posterior border – has a shallow groove for tendons of peroneus longus and peroneus brevis.
Lateral surface – subcutaneous, easily palpable.
Tip of lateral malleolus – attachment for calcaneofibular ligament.
Head upward, lateral malleolus downward.
Smooth articular facet faces medially.
The groove for peroneal tendons lies posteriorly.
→ The side corresponds to the position of the lateral malleolus.
| Region | Muscles Attached |
|---|---|
| Head | Biceps femoris, fibular collateral ligament |
| Upper two-thirds anterior surface | Extensor digitorum longus, Extensor hallucis longus |
| Lateral surface | Peroneus longus, Peroneus brevis |
| Posterior surface | Soleus, Flexor hallucis longus |
| Lower fourth medial surface | Peroneus tertius |
| Interosseous border | Interosseous membrane |
| Centre | Time of Appearance | Fusion with Shaft |
|---|---|---|
| Primary centre (shaft) | 8th week intrauterine life | — |
| Secondary centre (lower end) | 1st year | 18–20 years |
| Secondary centre (upper end) | 3–4 years | 20–25 years |
Lower end ossifies first but fuses later.
Upper end ossifies later but fuses first.
→ This is the reverse of the pattern seen in the tibia.
“Lower first, upper last — but upper joins first, lower joins last.”
Fibular neck fracture – may injure common peroneal nerve, leading to:
Foot drop (loss of dorsiflexion and eversion).
Sensory loss over dorsum of foot.
Fibular shaft fracture – usually accompanies tibial fracture; rarely isolated because it’s non-weight-bearing.
Avulsion fractures – at the lateral malleolus, due to pull of lateral ligaments of ankle.
A bimalleolar fracture involving lateral and medial malleoli.
Occurs due to forcible eversion of foot.
The lateral malleolus is fractured due to tension of the deltoid ligament pulling the medial malleolus and pushing the talus laterally.
Fibular grafts:
Commonly used for bone grafting, since fibula is expendable and non-weight-bearing.
Middle third is preferred for graft harvest.
Free vascularized fibular grafts are used in reconstructive surgery of long bones and mandible.
The common peroneal nerve winds around the neck of fibula, making it vulnerable in:
Fibular head fractures.
Plaster casts or tight bandages.
Injury causes foot drop and loss of eversion.
Lateral malleolus extends lower and posterior to medial malleolus → stabilizes ankle joint and prevents lateral displacement of talus.
Provides attachment for the lateral ligament complex:
Anterior talofibular ligament
Posterior talofibular ligament
Calcaneofibular ligament
Length of fibula is used for height estimation in anthropology.
Epiphyseal union timing helps in age estimation in forensic medicine.
Head of fibula – palpable below lateral side of knee joint; landmark for nerve block.
Lateral malleolus – forms the outer prominence of ankle; used in assessing malleolar fractures.
Fibular hemimelia – congenital absence or underdevelopment of fibula, leading to shortening of limb and foot deformities.
Fibular malunion – improper healing can cause rotational deformities affecting gait.
The skeleton of the foot is formed by 26 bones, arranged to provide support, balance, and locomotion.
These bones are grouped into three parts:
Tarsus (Tarsal bones) – 7 bones
Metatarsus (Metatarsal bones) – 5 bones
Phalanges (Toes) – 14 bones
The tarsal bones form the posterior half of the foot and are responsible for forming the arches and bearing body weight.
Talus
Calcaneus
Navicular
Cuboid
Medial cuneiform
Intermediate cuneiform
Lateral cuneiform
Proximal row → Talus and Calcaneus
Intermediate row → Navicular
Distal row → Three cuneiforms and Cuboid
Mnemonic: “Tiger Cubs Need MILC”
(Talus, Calcaneus, Navicular, Medial–Intermediate–Lateral cuneiforms, Cuboid)
The talus articulates with tibia and fibula to form the ankle joint.
The calcaneus forms the heel and articulates with talus and cuboid.
The navicular lies in front of talus, behind the cuneiforms.
The cuboid lies lateral, articulating with calcaneus and 4th–5th metatarsals.
The cuneiforms (medial, intermediate, lateral) articulate with navicular and first three metatarsals.
The talus is the second largest tarsal bone and the only bone connecting the foot to the leg.
It transmits body weight from the tibia to the calcaneus and forefoot.
Unique feature: no muscular attachments → entirely covered by articular cartilage and ligaments.
Head
Neck
Body
Rounded and directed forward and slightly downward and medial.
Articulates:
Anteriorly → with navicular bone (forming talonavicular joint).
Inferiorly → with calcaneus via anterior subtalar facet.
The head supports the spring ligament (plantar calcaneonavicular ligament).
Narrow constricted part between head and body.
Upper surface → groove for dorsalis pedis artery.
Inferior surface → sulcus tali, forming tarsal sinus with sulcus calcanei.
Ligament attachments:
Cervical ligament and interosseous talocalcaneal ligament in the sinus tarsi.
Largest part, cuboidal in shape, with five surfaces:
| Surface | Features / Articulations |
|---|---|
| Superior | Trochlear surface articulates with tibia → forms ankle joint |
| Inferior | Three facets for calcaneus (posterior, middle, anterior) |
| Medial | Comma-shaped facet for medial malleolus |
| Lateral | Triangular facet for lateral malleolus |
| Posterior | Groove for flexor hallucis longus tendon; lateral and medial tubercles on either side |
Posterior process:
Lateral tubercle – attachment for posterior talofibular ligament.
Medial tubercle – attachment for posterior talocalcaneal ligament.
Between them: groove for flexor hallucis longus.
Head faces forward, medially, and downward.
Larger facet on lateral side for fibula.
Groove on posterior surface runs obliquely downward and medially.
→ Bone belongs to that side.
Superiorly – with tibia (ankle joint)
Laterally – with fibula (ankle joint)
Inferiorly – with calcaneus (subtalar joint)
Anteriorly – with navicular (talonavicular joint)
| Centre | Time of Appearance | Fusion / Remarks |
|---|---|---|
| Primary centre | 7th month intrauterine life | — |
| Secondary centre (for lateral tubercle) | 8–10 years | May fail to fuse, forming os trigonum |
The talus ossifies from a single centre, but occasionally a separate secondary centre appears for the lateral tubercle of posterior process.
Ossification complete by 20 years.
Common sites: Neck and body.
Mechanism: Fall from height or forced dorsiflexion of foot.
Complication: High risk of avascular necrosis (AVN) of body due to disrupted blood supply (mostly from posterior tibial and dorsalis pedis arteries).
Hawkins classification used for neck fractures.
Occurs when the secondary ossification centre of lateral tubercle fails to fuse → accessory bone (os trigonum).
May cause posterior ankle pain, especially in ballet dancers and footballers due to repetitive plantar flexion.
Tarsal coalition: Fusion between talus and calcaneus or navicular → restricted inversion/eversion, flatfoot.
Talipes equinovarus (clubfoot): Medial rotation of talus leads to inward-turned foot.
Collapse of the medial longitudinal arch, commonly due to stretching of the spring ligament beneath the talar head.
The head of talus moves downward and medially → foot appears flat on the ground.
Subtalar dislocation: Talus remains in ankle mortise, but calcaneus and navicular are displaced medially or laterally.
Total dislocation of talus: Rare but serious; disrupts all articular connections, often causing necrosis.
Blood supply mainly from:
Posterior tibial artery → via tarsal canal branch.
Dorsalis pedis artery → via sinus tarsi branch.
Perforating peroneal artery.
Because of poor anastomosis, talar fractures are prone to avascular necrosis.
Lateral view (Harris-Beath view) helps assess tarsal coalition and talar fractures.
Ossification pattern aids in fetal maturity estimation.
Talectomy (excision of talus) may be performed in severe clubfoot unresponsive to correction.
Talar replacement prosthesis is rarely used due to complex blood supply.
The calcaneus (or heel bone) is the largest tarsal bone and forms the prominence of the heel.
It lies below the talus and behind the cuboid.
Functionally, it transmits the weight of the body from the talus to the ground.
It forms part of both:
Subtalar joint (with talus above)
Calcaneocuboid joint (with cuboid in front)
To hold the bone in anatomical position:
The posterior surface (for Achilles tendon) faces backward.
The anterior articular facet faces forward.
The sustentaculum tali projects medially.
→ The bone belongs to the side of the sustentaculum tali.
The calcaneus has six surfaces: superior, inferior, anterior, posterior, medial, and lateral.
Divided into three areas (from behind forward):
Posterior area: Rough, for attachment of calcaneal (Achilles) tendon and bursa.
Middle area: Bears the posterior articular facet for talus (forming part of subtalar joint).
Anterior area: Bears the middle and anterior articular facets for talus, separated by sulcus calcanei (forms tarsal sinus with sulcus tali of talus).
Rough, with three tubercles:
Medial process of tuberosity: Large, for origin of abductor hallucis and flexor digitorum brevis.
Lateral process: Smaller, for origin of abductor digiti minimi.
Anterior tubercle: For attachment of long plantar ligament.
Bears a saddle-shaped facet for articulation with the cuboid bone (calcaneocuboid joint).
Divided into three parts:
Upper smooth area: For retrocalcaneal bursa.
Middle rough area: For insertion of tendo calcaneus (Achilles tendon).
Lower rough area: For origin of plantar aponeurosis and abductor digiti minimi.
Shelf-like projection called sustentaculum tali, which:
Supports the head of talus.
Has a groove below it for flexor hallucis longus tendon.
Gives attachment to spring ligament (plantar calcaneonavicular ligament).
Provides surface for tibialis posterior tendon attachment.
Marked by:
Peroneal trochlea (fibular trochlea) between the tendons of peroneus longus (below) and peroneus brevis (above).
Peroneal tubercle acts as pulley for peroneal tendons.
Smooth area for retinaculum attachment.
Superiorly – with talus (subtalar joint).
Anteriorly – with cuboid (calcaneocuboid joint).
| Region | Structures Attached |
|---|---|
| Posterior surface | Tendo calcaneus, plantar aponeurosis |
| Inferior surface | Abductor hallucis, Flexor digitorum brevis, Abductor digiti minimi |
| Medial surface | Spring ligament, Flexor retinaculum |
| Lateral surface | Peroneal retinacula, Peroneal trochlea |
| Anterior surface | Long plantar ligament |
| Sustentaculum tali | Spring ligament, Tibialis posterior tendon |
| Centre | Time of Appearance | Fusion |
|---|---|---|
| Primary centre | 6th month intrauterine life | — |
| Secondary centre (for calcaneal tuberosity) | 6–8 years | 14–16 years |
The calcaneus ossifies from two centres:
Primary centre – forms most of the bone.
Secondary centre – appears for the posterior tuberosity (insertion of Achilles tendon).
Failure of fusion of the secondary centre may form an accessory bone called os calcaneus secundarius.
Commonest tarsal bone to fracture.
Mechanism: Fall from height landing on heel (axial compression).
Fracture types:
Comminuted fracture: Disruption of subtalar joint and calcaneal body.
Avulsion fracture: At the posterior tuberosity (due to violent pull of Achilles tendon).
Radiological feature: Decrease in Böhler’s angle (normally 20°–40°) indicates collapse of calcaneus.
Chronic traction on the medial process of calcaneal tuberosity → formation of bony outgrowth (spur) at plantar fascia attachment.
Causes heel pain (plantar fasciitis), especially during first steps in the morning.
Sudden, forceful dorsiflexion (in athletes) can rupture the tendon at its insertion on the posterior surface of calcaneus.
Causes inability to stand on toes.
Treated by surgical repair or immobilization.
Weakness or stretching of the spring ligament under the sustentaculum tali leads to descent of talar head, flattening the medial longitudinal arch.
Pain occurs along medial side of heel.
Deformity due to inversion and adduction of calcaneus with medial rotation of talus.
Leads to inward turning of sole and heel.
Seen in growing children (8–14 years).
Due to inflammation of secondary ossification centre of calcaneal tuberosity from overuse.
Presents with heel pain during activity.
Böhler’s angle and Gissane’s angle on X-ray help evaluate calcaneal fractures.
Calcaneal bone grafts are used in reconstructive foot surgery.
Peroneal tubercle serves as an important surgical landmark for lateral foot incisions.
The navicular bone is a boat-shaped tarsal bone located in the medial side of the foot, between the head of the talus (behind) and the three cuneiform bones (in front).
It forms part of the medial longitudinal arch and helps in weight transmission from the talus to the forefoot.
Posterior Surface
Concave and oval.
Articulates with the head of the talus (forming the talonavicular joint).
Anterior Surface
Convex, divided into three facets for articulation with the medial, intermediate, and lateral cuneiform bones.
Medial Surface
Prominent tuberosity projects downward and medially.
Gives insertion to the tibialis posterior tendon — key structure maintaining the medial arch of the foot.
Lateral Surface
Small facet for articulation with the cuboid bone (variable).
Superior Surface
Rough and narrow; for ligament attachment.
Inferior Surface
Rough for attachment of plantar calcaneonavicular (spring) ligament and part of tibialis posterior tendon.
Concave surface faces posteriorly, convex surface anteriorly.
Tuberosity projects medially.
→ The bone belongs to the side of the projecting tuberosity.
Posteriorly – Talus
Anteriorly – Three cuneiforms
Laterally – Cuboid (occasionally)
| Centre | Time of Appearance | Remarks |
|---|---|---|
| Primary centre | 3rd year (in girls), 4th year (in boys) | Single centre forms entire bone |
| Accessory centre (Navicular tuberosity) | Occasionally present | Failure to fuse → Accessory navicular bone |
The navicular is the last tarsal bone to ossify.
Ossification completes around 12–14 years.
Accessory Navicular Bone (Os Tibiale Externum)
Results from non-fusion of the accessory centre at the tuberosity.
Causes pain and tenderness on medial side of foot, may mimic fracture.
Navicular Fracture
Occurs due to indirect trauma or stress (e.g., in runners).
May cause collapse of medial arch.
Flatfoot (Pes Planus)
Displacement of talus head downward stretches the spring ligament, pressing against the navicular, producing flat appearance.
Tarsal Coalition
Fusion between navicular and calcaneus (calcaneonavicular coalition) → restricted inversion/eversion.
The three cuneiform bones are wedge-shaped tarsal bones lying in the distal row of tarsus, between the navicular bone (behind) and the first three metatarsals (in front).
They form part of the medial longitudinal and transverse arches of the foot.
| Bone | Position | Articulates Anteriorly With |
|---|---|---|
| Medial cuneiform | Largest, most medial | 1st metatarsal |
| Intermediate cuneiform | Smallest, between the other two | 2nd metatarsal |
| Lateral cuneiform | Between intermediate cuneiform and cuboid | 3rd metatarsal |
Largest of the three and wedge-shaped, base directed downward.
Medial surface is subcutaneous and easily palpable.
Anterior surface – articulates with base of 1st metatarsal.
Posterior surface – articulates with navicular bone.
Lateral surface – articulates with intermediate cuneiform and base of 2nd metatarsal.
Inferior surface – rough for tibialis posterior and peroneus longus attachments.
Medial surface: Tibialis anterior insertion.
Lateral surface: Peroneus longus tendon crosses inferiorly.
Inferior surface: Partly gives origin to flexor hallucis brevis.
Smallest of the three.
Wedge-shaped, with base directed upward.
Posterior surface: Articulates with navicular bone.
Anterior surface: Articulates with 2nd metatarsal base.
Medial surface: Articulates with medial cuneiform.
Lateral surface: Articulates with lateral cuneiform.
Superior and inferior surfaces: Rough for ligament attachment.
Lies between intermediate cuneiform (medial) and cuboid (lateral).
Posterior surface: Articulates with navicular.
Anterior surface: Articulates with 3rd metatarsal.
Medial surface: Articulates with intermediate cuneiform and 2nd metatarsal.
Lateral surface: Articulates with cuboid and 4th metatarsal.
Gives partial origin to flexor hallucis brevis.
| Bone | Centre Appearance | Fusion Completed |
|---|---|---|
| Lateral cuneiform | 1st year | 12 years |
| Medial cuneiform | 2nd year | 12 years |
| Intermediate cuneiform | 3rd year | 12 years |
Occasionally, the medial cuneiform may have two ossification centres that later fuse.
Ossification usually completes by 12 years of age.
Fractures
Rare, due to protection by surrounding bones and strong ligaments.
Usually part of complex Lisfranc fracture-dislocation (at tarsometatarsal joint).
Cuneiform Coalition
Fusion between cuneiforms may lead to restricted midfoot movement and foot stiffness.
Flatfoot (Pes Planus)
Collapse of medial arch involves downward displacement of medial cuneiform; weight-bearing line shifts medially.
Accessory Cuneiforms
Occasionally found as small separate ossicles near normal bones (harmless, but may mimic fracture on X-ray).
Palpation
The medial cuneiform is palpable just anterior to the navicular tuberosity — a surface landmark in medial foot.
The cuboid is the most lateral bone of the distal row of tarsus.
It is cube-shaped, forming the lateral part of the foot’s skeleton.
It lies in front of the calcaneus and behind the 4th and 5th metatarsal bones.
It participates in forming the lateral longitudinal arch of the foot.
Anterior Surface
Divided into two facets for articulation with the bases of the 4th and 5th metatarsals.
Posterior Surface
Saddle-shaped facet articulates with the calcaneus (calcaneocuboid joint).
Medial Surface
Articulates with the lateral cuneiform and navicular (occasionally).
Lateral Surface
Smooth and forms the outer border of the foot.
Inferior (Plantar) Surface
Prominent tuberosity near its posterior part for attachment of the long plantar ligament.
Has a groove for peroneus longus tendon, obliquely directed forward and medially.
Medial end of the groove shows a ridge (peroneal ridge) and a small sesamoid bone within the tendon.
Superior Surface
Rough, non-articular area for ligament attachment.
Posteriorly – Calcaneus
Medially – Lateral cuneiform and sometimes navicular
Anteriorly – 4th and 5th metatarsals
| Centre | Time of Appearance | Fusion Completed |
|---|---|---|
| Primary centre | 9th month intrauterine life (just before birth) | 12 years |
The cuboid is the first tarsal bone to ossify after birth and is used in determining full-term maturity of the newborn.
Cuboid Syndrome
Partial subluxation or malalignment of cuboid bone due to peroneus longus traction.
Causes lateral foot pain and difficulty in weight bearing.
Common in athletes and ballet dancers.
Fractures
Usually due to crush injuries or forced inversion of the foot.
May cause collapse of the lateral longitudinal arch.
Accessory Ossicles
Os peroneum – small sesamoid bone sometimes found within the peroneus longus tendon near the cuboid groove.
The metatarsus consists of five metatarsal bones, numbered I to V from medial to lateral side.
They form the skeleton of the forefoot and connect the tarsus with the phalanges.
Each metatarsal is a miniature long bone with:
Base – proximal, articulating with tarsal bones
Shaft – body
Head – distal, articulating with proximal phalanges
| Metatarsal | Special Characteristics |
|---|---|
| 1st | Shortest, thickest, bears body weight; base has facet for medial cuneiform and sesamoid bones under head. |
| 2nd | Longest; base wedged between medial and lateral cuneiforms (least mobile). |
| 3rd | Base articulates with lateral cuneiform. |
| 4th | Base articulates with cuboid and lateral cuneiform. |
| 5th | Has prominent tuberosity (styloid process) on base for peroneus brevis tendon insertion. |
| Bone | Posteriorly | Anteriorly | Laterally / Medially |
|---|---|---|---|
| 1st | Medial cuneiform | 1st proximal phalanx | — |
| 2nd | Medial, intermediate, lateral cuneiforms | 2nd proximal phalanx | 1st and 3rd metatarsals |
| 3rd | Lateral cuneiform | 3rd proximal phalanx | 2nd and 4th metatarsals |
| 4th | Cuboid and lateral cuneiform | 4th proximal phalanx | 3rd and 5th metatarsals |
| 5th | Cuboid | 5th proximal phalanx | 4th metatarsal |
| Centre | Time of Appearance | Fusion |
|---|---|---|
| Primary centre (shaft) | 9th week intrauterine life | — |
| Secondary centre (head) | 3rd year (1st – base) | 18 years |
1st metatarsal – secondary centre appears at the base.
2nd to 5th metatarsals – secondary centres appear at the heads.
All fuse with shaft by 18 years.
March Fracture
Stress fracture of 2nd or 3rd metatarsal from repetitive stress (common in soldiers, dancers).
Causes dorsal foot pain and swelling.
Jones Fracture
Transverse fracture at the base of 5th metatarsal, due to peroneus brevis pull during inversion injury.
Pain and tenderness at lateral midfoot.
Hallux Valgus (Bunion)
Lateral deviation of 1st metatarsophalangeal joint, often with medial bony prominence (bunion).
Metatarsalgia
Pain in forefoot due to collapsed transverse arch; involves heads of 2nd and 3rd metatarsals.
There are 14 phalanges in the foot:
2 in the great toe (hallux)
3 in each of the other four toes
Arranged as: proximal, middle, and distal phalanges (except great toe).
Each phalanx has:
Base – proximal, articulates with metatarsal or preceding phalanx
Shaft – middle part
Head – distal, small and rounded (or expanded distally in distal phalanges)
Proximal phalanges: Longest; articulate with metatarsal heads.
Middle phalanges: Absent in great toe.
Distal phalanges: Flattened distal ends supporting the nail bed.
The distal phalanx of the great toe is thick and strong, bearing much of the push-off weight in walking.
| Centre | Time of Appearance | Fusion |
|---|---|---|
| Primary centre (shaft) | 9th–10th week intrauterine life | — |
| Secondary centre (base) | 3rd year | 18 years |
Each phalanx ossifies from two centres — one for the shaft, and one for the base (which appears later).
Ossification completes by 18 years of age.
Collapse of medial longitudinal arch due to ligament or muscle weakness.
Navicular, talus, and cuneiform bones sink downward.
Exaggerated medial arch due to contracture of intrinsic foot muscles or neurological disorders.
Deformities of phalanges due to imbalance between long and short toe muscles.
Pain under metatarsal heads due to loss of transverse arch or fat pad atrophy.
Common small extra bones: os peroneum, os trigonum, accessory navicular — may mimic fractures radiologically.
Sesamoid bones are small nodules of bone embedded within tendons where they pass over joints or pressure points.
They reduce friction, protect tendons, and improve the mechanical efficiency of muscles.
Two constant sesamoid bones under the head of 1st metatarsal:
Medial (tibial) sesamoid → in tendon of flexor hallucis brevis (medial head)
Lateral (fibular) sesamoid → in tendon of flexor hallucis brevis (lateral head)
Occasional sesamoids may be present in tendons of:
Peroneus longus (near cuboid groove)
Tibialis anterior or posterior
Flexor digitorum longus in toes
Sesamoiditis
Inflammation due to repetitive pressure on 1st metatarsal sesamoids (common in runners and dancers).
Causes forefoot pain and tenderness beneath the great toe.
Fracture of Sesamoids
May mimic bipartite sesamoid (which has smooth margins).
Pain aggravated by toe dorsiflexion.
Bipartite Sesamoid
Congenital division into two parts; usually painless unless traumatized.
Functionally Important
Protect tendons from wear.
Increase leverage of flexor hallucis brevis during toe-off in walking.
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