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Student copy. Fascia and Compartments

Fascia and Compartments

Lower Leg Compartments

  • Superficial Posterior Compartment

  • Deep Posterior Compartment

  • Lateral Compartment

  • Anterior Compartment

Source

Dr. U Offor, Queen Mary University of London, Barts and the London

Learning Objectives

  • Describe the fascial compartments of the arm and forearm.

  • Describe the fascial compartments of the thigh and leg.

  • Learn the significance of compartments to neurovascular supply.

  • Describe the pathophysiology, diagnosis, and treatment of Acute Compartment Syndrome of the limb.

Compartment Overview

Definition: A compartment is a closed area containing muscle groups, nerves, and blood vessels, all surrounded by fascia. Muscles are organized into different compartments, separated by fascia.

Fascia

Definition: Fascial tissue is a connective tissue layer that envelopes and separates muscle groups and organs throughout the body.Function: Holds bodily structures in organized arrangements.

Types:

  • Superficial Fascia: Loose connective tissue located between the dermis and deep fascia.

  • Deep Fascia: Dense connective tissue that covers deeper body regions, creating intermuscular septa that divide muscles into compartments.

Superficial Fascia

  • Composition: Loose connective tissue containing adipose tissue and structures such as retinacula cutis.

Deep Fascia

  • Characteristics: Dense connective tissue.

    • Forms fibrous membranes enclosing muscle groups.

    • Provides a tough covering and separates muscles with similar functions within compartments.

Upper Limb Compartments

The Arm

  • Location: Extends from shoulder to elbow.

  • Divisions: Anterior and posterior compartments divided by medial and lateral intermuscular septa.

Anterior/Flexor Fascial Compartment of the Upper Arm

  • Muscles: Biceps brachii, coracobrachialis, brachialis.

  • Blood Supply: Brachial artery.

  • Nerve Supply: Musculocutaneous nerve (B B C acronym).

Posterior/Extensor Compartment of the Upper Arm

  • Muscles: Triceps brachii (long head, lateral head, medial head).

  • Nerve Supply: Radial nerve.

  • Blood Supply: Brachial artery (profunda brachii).

Forearm Compartments

Anterior/Flexor Compartment

  • Muscles: Pronator teres, palmaris longus, flexor carpi radialis, etc.

  • Nerve Supply: Median nerve mostly, and ulnar nerve (for flexor carpi ulnaris).

Posterior/Extensor Compartment

  • Components: Superficial (7 muscles) and deep (5 muscles) layers.

  • Nerve Supply: Radial nerve.

Detailed Anatomy of Compartments in the Forearm

  • Anterior Superficial Layer: 3 muscles; Median nerve.

  • Anterior Intermediate Layer: 1 muscle (flexor digitorum superficialis).

  • Anterior Deep Layer: 3 muscles; Median and ulnar nerves involved.

Thigh Compartments

Anterior Compartment

  • Muscles: Quadriceps (Rectus femoris, vastus medialis, vastus intermedius, vastus lateralis).

  • Nerve Supply: Femoral nerve.

  • Blood Supply: Femoral artery branches.

Medial Compartment

  • Muscles: Gracilis, obturator externus, adductor muscles.

  • Nerve Supply: Obturator nerve.

  • Blood Supply: Obturator artery.

Posterior Compartment

  • Muscles: Hamstrings (Semitendinosus, biceps femoris, semimembranosus).

  • Nerve Supply: Sciatic nerve.

  • Blood Supply: Profunda femoris.

Leg Compartments

Overview

  • Compartment Types:

    • Superficial posterior

    • Deep posterior

    • Anterior

    • Lateral/Fibular

Anterior Compartment

  • Nerve Supply: Deep peroneal (fibular) nerve.

  • Blood Supply: Anterior tibial artery.

Lateral/Fibular Compartment

  • Nerve Supply: Superficial peroneal (fibular) nerve.

  • Blood Supply: Fibular artery.

Posterior Compartment

  • Components: Superficial and deep (2 layers).

  • Nerve Supply: Tibial nerve.

  • Blood Supply: Posterior tibial artery.

Neurovascular Organization

Neurovascular structures (nerves, arteries, veins) run through specific compartments, ensuring targeted supply.Example: anterior compartment muscles supplied by deep peroneal nerve and anterior tibial artery.

Compartment Syndrome

  • Definition: Increased pressure within a compartment leading to compromised blood flow and nerve function.

  • Causes: Trauma, swelling, bleeding.

  • Consequences: Ischemia and nerve damage, requiring urgent fasciotomy.

Diagnosis

Key Signs (5 Ps)

  1. Pain: Severe, often out of proportion to injury.

  2. Paresthesia: Tingling or burning.

  3. Pallor: Pale skin due to reduced blood flow.

  4. Pulselessness: Rare, significant finding.

  5. Paralysis: Advanced ischemia indicator.

Pressure Monitoring

  • Measurement of intracompartmental pressure (diagnostic >30 mmHg of diastolic).

Treatment of Acute Compartment Syndrome

  • Immediate Actions: Fasciotomy to relieve pressure and restore blood flow.

  • Supportive Care: Fluid resuscitation and pain management.

  • Post-Treatment Monitoring: Assess for infection and functional recovery.