2. Definition
Page 2 – Definition
| Definition |
|---|
|
| Category | Key Elements |
| Structure | • Bones: Tibia (medial), Fibula (lateral)• Compartments: Anterior, Lateral, Superficial Posterior, Deep Posterior• Vessels: Anterior tibial, Posterior tibial, Fibular arteries• Nerves: Tibial, Superficial & Deep Peroneal |
| Function | • Supports body weight• Transfers force to ankle and foot• Enables ambulation and posture |
| Common Diseases | • Tibial/fibular fractures• Compartment syndrome• Deep vein thrombosis (DVT) |
| Diagnosis | • Physical exam• Imaging: X-ray, CT, MRI, Ultrasound• Labs: D-dimer, CK, CBC |
| Treatment | • Immobilization (casting)• Surgery (ORIF, fasciotomy)• Anticoagulation for DVT |
3. Anatomy
Page 3 – Applied Anatomy and Diagnostic Approach
U-SSPCT–C Table: Lower Leg
| Category | Subcategory | Details |
| Units (U) | Bone – Tibia | Medial, weight-bearing bone of the lower leg |
| Bone – Fibula | Lateral, slender, non-weight-bearing bone | |
| Muscle – Tibialis anterior | Anterior compartment | |
| Muscle – Extensor digitorum longus (EDL) | Anterior compartment | |
| Muscle – Extensor hallucis longus (EHL) | Anterior compartment | |
| Muscle – Fibularis tertius | Anterior compartment | |
| Muscle – Fibularis longus | Lateral compartment | |
| Muscle – Fibularis brevis | Lateral compartment | |
| Muscle – Gastrocnemius | Superficial posterior compartment | |
| Muscle – Soleus | Superficial posterior compartment | |
| Muscle – Plantaris | Superficial posterior compartment | |
| Muscle – Tibialis posterior | Deep posterior compartment | |
| Muscle – Flexor digitorum longus (FDL) | Deep posterior compartment | |
| Muscle – Flexor hallucis longus (FHL) | Deep posterior compartment | |
| Size | Length | ~35–40 cm in adult |
| Diameter | Tibia: thick and denseFibula: slender | |
| Shape | Tibia | Triangular shaft with anterior ridge |
| Fibula | Cylindrical, narrow, lateral | |
| Position |
|
Between knee and ankle Tibia is medial Fibula is lateral |
| Compartments | Anterior Lateral Superficial Posterior Deep Posterior |
|
| Character | Bone | Dense cortical bone, supports weight |
| Muscle | Vascular, Ccontractile, with compartmental differentiation |
|
| Nerve | Mixed motor and sensory conduction | |
| Time | Embryology | Limb buds form ~4th weekOssification ~8th–10th week |
| Aging | Epiphyseal fusion ~18–20 years Degenerative changes over time |
|
| Connections | Arterial Supply | Anterior tibial arteryPosterior tibial arteryFibular artery |
| Venous Drainage | Deep: venae comitantesSuperficial: great and small saphenous veins | |
| Lymphatic Drainage | Popliteal nodes (deep) Inguinal nodes (superficial) |
|
| Nerve Supply | Tibial nerve Common peroneal nerve Deep peroneal nerve Superficial peroneal nerve |
|
| Joints
Ligaments/Tendons |
Knee Joint Proximal tibiofibular joint Distal tibiofibular joint Ankle Joint Interosseous membrane |
4. Disease and Diagnosis
Page 4 – Clinical Diagnosis
1. Pathology by TCV Logic (15 Categories)
| Category | Example Diseases |
| Inflammatory / Immune | Vasculitis (e.g., polyarteritis nodosa) |
| Infection | Cellulitis, osteomyelitis |
| Neoplasm – Benign | Osteoid osteoma |
| Neoplasm – Malignant (Primary) | Osteosarcoma of the tibia |
| Neoplasm – Malignant (Metastatic) | Bone metastases from lung, prostate |
| Mechanical | Tibial stress fracture, shin splints |
| Trauma | Tibia or fibula fracture, crush injury |
| Metabolic | Osteomalacia, rickets |
| Circulatory | Deep vein thrombosis (DVT), chronic venous insufficiency |
| Inherited | Osteogenesis imperfecta |
| Infiltrative | Gaucher’s disease (marrow involvement) |
| Idiopathic | Chronic exertional compartment syndrome |
| Iatrogenic | Post-surgical complications, fasciotomy sequelae |
| Functional | Overuse injury, repetitive strain |
| Psychiatric | Somatic symptom disorder (leg pain without organic basis) |
2. Clinical Signs and Symptoms
| Symptom | Meaning or Implication |
| Pain (localized or diffuse) | Fracture, muscle strain, ischemia |
| Swelling | Trauma, DVT, compartment syndrome |
| Redness and warmth | Infection, thrombophlebitis |
| Numbness or tingling | Nerve compression, compartment syndrome |
| Calf tightness or tenderness | DVT, muscle injury |
3. Imaging Modalities
| Modality | Primary Use | When/Why Used |
| X-ray | Bone fractures, alignment | First-line in trauma settings |
| CT | Complex or occult fractures | 3D evaluation, preoperative planning |
| MRI | Soft tissue injury, marrow pathology | Tumor, stress fracture, infection |
| Ultrasound | DVT evaluation | Bedside, vascular flow assessment |
4. Laboratory Tests
| Test | Purpose | When/Why Used |
| D-dimer | Rule out thromboembolism | Elevated in suspected DVT/PE |
| CBC | Detect infection, anemia | Suspected osteomyelitis or trauma |
| Creatine Kinase (CK) | Muscle breakdown marker | Rhabdomyolysis, compartment syndrome |
5. Other Diagnostic Tools
| Tool | Use | Indication |
| Compartment pressure monitor | Measures intracompartmental pressure | Suspected compartment syndrome |
| Clinical exam (palpation, ROM, neurovascular check) | Bedside assessment | Initial evaluation of all patients |
| Doppler ultrasound | Vascular flow study | Suspected DVT, arterial insufficiency |