2. Definition

Page 2 – Definition

Definition and Overview
• The femur is the longest and strongest bone in the human body.
• It forms the upper segment of the lower limb.
• It acts as a structural pillar and kinetic lever for movement.
• It supports body weight during standing, walking, and running.
• It articulates proximally with the pelvis (hip joint) and distally with the tibia (knee joint).

Core Elements	Details
Structure	Proximal head, neck, shaft, distal condyles; surrounded by dense cortical and spongy bone
Function	Weight-bearing, locomotion, hip and knee joint articulation
Common Diseases	Fractures (neck, shaft), osteosarcoma, avascular necrosis
Diagnosis	Physical exam, X-ray, CT, MRI, bone scan
Treatment	ORIF (open reduction internal fixation), hip/knee replacement, chemotherapy (osteosarcoma), physiotherapy

3. Anatomy

Page 3 – Applied Anatomy and Diagnostic Approach

Table 1 – U-SSPCT–C (Structure in Discrete Bullet-Point Units)

Category	Units	Details
U – Units	Bone	• Femur
	Muscles	• Quadriceps: rectus femoris, vastus medialis, vastus intermedius, vastus lateralis• Hamstrings: biceps femoris, semitendinosus, semimembranosus• Gluteus maximus, medius, minimus• Adductors: longus, brevis, magnus
	Fasciae	• Fascia lata• Iliotibial tract
S – Size		• Length: ~45 cm in adult male• Thickest cortical bone in body
S – Shape		• Proximal head and neck• Slightly bowed shaft• Distal medial and lateral condyles
P – Position		• Thigh region of lower limb• Between hip and knee joints
C – Character		• Strong, load-bearing• Slightly flexible to accommodate stress and movement
T – Time (Development & Aging)		• Ossification starts in utero• Epiphyseal fusion complete by age 20• Susceptible to osteoporotic fracture with aging
C – Connections	Arterial Supply	• Profunda femoris artery• Medial and lateral circumflex femoral arteries
	Venous Drainage	• Femoral vein• Great saphenous vein
	Lymphatic Drainage	• Superficial and deep inguinal nodes
	Nerve Supply	• Femoral nerve (anterior thigh)• Obturator nerve (medial thigh)• Sciatic nerve (posterior thigh)
	Joints	• Hip joint (proximal articulation with acetabulum)• Knee joint (distal articulation with tibia and patella)
	Ligaments & Tendons	• Iliofemoral, pubofemoral, and ischiofemoral ligaments• Tendons: quadriceps, hamstrings, adductors

Imaging Modalities

Modality	Primary Use	When/Why Used
X-ray	Evaluate fractures, alignment, joint degeneration	First-line in trauma or arthritis
CT	Complex fracture assessment, surgical planning	Useful for 3D visualization and acetabular involvement
MRI	Detect marrow edema, AVN, tumors	Most sensitive for early AVN and soft tissue pathology
Bone Scan	Screen for tumors, stress fractures, infection	Whole-body or focal uptake evaluation
Ultrasound	Assess soft tissue (e.g., hematoma)	Limited use; adjunct in trauma or vascular assessment

Laboratory Tests

Test	Purpose	When Used
CBC	Infection, anemia, blood loss	Trauma, neoplasm, systemic illness
ESR/CRP	Detect inflammation	Suspected AVN, infection, tumor
Alkaline Phosphatase	Bone activity indicator	Tumors, metabolic bone disease, Paget’s disease
Calcium/Vitamin D	Bone mineralization	Osteoporosis, metabolic bone disease

Other Diagnostic Tools

Tool	Use	Indication
Biopsy	Histological diagnosis	Tumors such as osteosarcoma or metastases
Angiography	Vascular mapping	AVN, trauma with vascular injury suspicion
EMG/NCS	Nerve integrity	Sciatic neuropathy, femoral nerve entrapment
Gait analysis	Functional evaluation	Post-fracture rehab and joint function review

 

4. Disease and Diagnosis

Page 4 – Clinical Diagnosis

1. Pathology

Category	Example Pathologies
Inflammatory/Immune	Rheumatoid arthritis involving the hip or knee
Infectious	Osteomyelitis of the femur
Neoplastic – Benign	Osteoid osteoma, enchondroma
Neoplastic – Malignant	Osteosarcoma, metastatic carcinoma
Mechanical	Femoroacetabular impingement, leg length discrepancy
Trauma	Femoral neck fracture, shaft fracture, intertrochanteric fracture
Metabolic	Osteoporosis with fragility fracture
Circulatory	Avascular necrosis of the femoral head
Inherited	Developmental dysplasia of the hip (DDH)
Infiltrative	Paget’s disease involving femur
Idiopathic	Slipped capital femoral epiphysis (in adolescents)
Iatrogenic	Prosthesis complications after hip replacement
Functional	Gait abnormalities post-fracture
Psychological	Conversion disorders presenting with limb weakness
Psychiatric	Non-use or neglect due to severe depression or catatonia

2. Clinical Signs and Symptoms

Symptom	Meaning or Implication
Hip/knee pain	Arthritis, trauma, AVN
Swelling or bruising	Fracture, trauma
Inability to bear weight	Fracture or severe joint disease
Limb shortening	Neck or shaft fracture
Deformity or angulation	Malunion or severe trauma

3. Imaging Modalities

Modality	Use	When/Why Used
X-ray	Fractures, arthritis, tumors	First-line tool
CT	Complex fractures, pre-op	3D reconstructions needed
MRI	AVN, marrow/tumor pathology	High tissue contrast
Bone scan	Tumor, infection, stress fracture	Whole-body overview

4. Laboratory Tests

Test	Purpose	When Used
CBC	Infection, anemia	In trauma, infection, malignancy
ESR/CRP	Inflammation	Suspected infection or tumor
Alkaline phosphatase	Bone turnover	Tumors, Paget’s disease

5. Other Diagnostic Tools

Tool	Use	Indication
Joint aspiration	Rule out septic arthritis	Hip effusion with fever
Biopsy	Tumor diagnosis	Suspected neoplasm
Gait analysis	Rehab planning	Functional recovery evaluation

5. History and Culture

Page 5 – History, Culture, and Art

1. History of Anatomy

Topic	Details
Classical Anatomy	Galen and Vesalius described the femur’s structure and function in early anatomical texts
Modern Understanding	Development of orthopedic surgery refined our understanding of femoral mechanics and vascular supply

2. History of Physiology

Topic	Details
Weight-bearing analysis	Enlightenment-era studies explored mechanical loading and leverage through the femur
Biomechanics	20th-century biomechanics quantified stress, force, and muscular interplay of the femur during gait

3. History of Diagnosis

Topic	Details
Clinical exam	Trendelenburg sign for hip abductor weakness
Imaging evolution	Radiography transformed detection of fractures, AVN, and tumors

4. History of Imaging

Topic	Details
X-ray	Introduced in 1895, revolutionized fracture care
MRI	Became standard in evaluating AVN and tumors of the femoral head
CT	Enabled surgical planning for complex femur fractures

5. History of Laboratory Testing

Topic	Details
Bone markers	Used in metabolic disease and cancer follow-up
Inflammatory markers	ESR/CRP became standard in orthopedic infection workup

6. History of Therapies

Topic	Details
Traction	Historic treatment for fractures pre-surgery
Internal fixation	ORIF revolutionized healing and mobility
Hip arthroplasty	Introduced in 1960s; now routine for elderly fracture

7. Cultural Meaning

Culture	Symbolism
Global	Femur symbolizes strength, mobility, and vitality
Ancient burial practices	Femur often preserved with skull as part of ritual

8. Artistic Representations

Artist/Context	Representation
Michelangelo	Accurately depicted hip and thigh musculature in sculpture
Modern art	X-ray overlays of fractured femurs symbolize aging and resilience

9. Notable Figures

Figure	Contribution
Sir John Charnley	Pioneer of total hip arthroplasty
Julius Wolff	Described Wolff’s law of bone adaptation to stress

10. Quotes

Quote	Attribution
“The femur bears not only the body but the burden of time.”	Anonymous orthopedic maxim
“Healing is a matter of time, but it is sometimes also a matter of opportunity.”	Hippocrates

7. MCQ's

Page 6 – MCQs

Basic Science MCQ 1

Which of the following arteries primarily supplies the head of the femur in adults?

A. Obturator artery
B. Medial circumflex femoral artery
C. Lateral circumflex femoral artery
D. Inferior gluteal artery

Correct Answer	Explanation
B. Medial circumflex femoral artery	In adults, this artery supplies the majority of blood to the femoral head via the retinacular vessels.

Incorrect Options	Why Incorrect
A. Obturator artery	Plays a minor role through ligamentum teres in children
C. Lateral circumflex femoral artery	Supplies anterior structures, not primarily the femoral head
D. Inferior gluteal artery	Not a primary contributor to femoral head perfusion

Basic Science MCQ 2

Which muscle inserts on the lesser trochanter of the femur?

A. Gluteus minimus
B. Iliopsoas
C. Rectus femoris
D. Sartorius

Correct Answer	Explanation
B. Iliopsoas	The psoas major and iliacus insert on the lesser trochanter, functioning as hip flexors.

Incorrect Options	Why Incorrect
A. Gluteus minimus	Inserts on greater trochanter
C. Rectus femoris	Inserts on tibial tuberosity via patellar tendon
D. Sartorius	Inserts medially on proximal tibia

Clinical MCQ 1

A 75-year-old female falls and cannot bear weight. X-ray shows a femoral neck fracture. What is the most common complication if left untreated?

A. Osteomyelitis
B. Avascular necrosis
C. Osteoarthritis
D. Muscle atrophy

Correct Answer	Explanation
B. Avascular necrosis	The femoral head’s blood supply can be disrupted, leading to ischemia and necrosis.

Incorrect Options	Why Incorrect
A. Osteomyelitis	Rare unless there is open wound or surgery
C. Osteoarthritis	Can occur but not the most immediate risk
D. Muscle atrophy	Occurs with immobilization but not the primary complication

Clinical MCQ 2

Which sign is most useful to detect gluteus medius weakness in femur-related pathology?

A. Thomas test
B. Trendelenburg sign
C. Ober’s test
D. Lachman test

Correct Answer	Explanation
B. Trendelenburg sign	Indicates abductor weakness, commonly due to femoral head/neck pathology or hip replacement.

Incorrect Options	Why Incorrect
A. Thomas test	Assesses hip flexor tightness
C. Ober’s test	Evaluates IT band tightness
D. Lachman test	Tests ACL stability, not femur function

Radiology MCQ 1

What is the most sensitive modality for early detection of avascular necrosis of the femoral head?

A. X-ray
B. CT
C. MRI
D. Bone scan

Correct Answer	Explanation
C. MRI	MRI detects early marrow changes before they appear on X-ray or CT.

Incorrect Options	Why Incorrect
A. X-ray	Normal in early AVN
B. CT	Detects structural damage but late changes
D. Bone scan	Sensitive but less specific than MRI

Radiology MCQ 2

Which view is best for visualizing a femoral neck fracture on X-ray?

A. Lateral knee
B. Oblique pelvis
C. Cross-table lateral hip
D. Sunrise patella

Correct Answer	Explanation
C. Cross-table lateral hip	Provides best view of femoral neck alignment in trauma patients.

Incorrect Options	Why Incorrect
A. Lateral knee	Focuses on distal femur, not neck
B. Oblique pelvis	May help but not specific
D. Sunrise patella	Evaluates patellofemoral joint

Radiology MCQ 3

Which X-ray finding is classic for osteosarcoma of the femur?

A. Joint space narrowing
B. Sunburst periosteal reaction
C. Ground-glass opacity
D. Onion-skin layering

Correct Answer	Explanation
B. Sunburst periosteal reaction	Classic appearance due to aggressive new bone formation radiating outward from tumor.

Incorrect Options	Why Incorrect
A. Joint space narrowing	Seen in arthritis, not cancer
C. Ground-glass opacity	Describes lung findings
D. Onion-skin layering	Typical of Ewing’s sarcoma

8. Memory Image

Page 7 – Memory Image

 

Symbolic Element	Meaning
Towering column	Structural strength and vertical load-bearing
Golden vascular vines	Lifeline of perfusion and healing
Fracture fissures	Susceptibility to trauma
Implants	Surgical repair and biomechanical restoration