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.