Peripheral Nerve Injuries:Repair and Reconstruction

Dr hawre

• ANATOMY OF THE PERIPHERAEL NRVES• PHYSIOLOGY OF THE PERIPHERAL NERVE

ANATOMY OF THE PERIPHERAEL NRVES

Gross Anatomy Neuronal and Neural Anatomy

Gross Anatomy

Neuronal and Neural Anatomy

Neuronal and Neural Anatomy

Topography

IntraneuralTopography

PHYSIOLOGY O F THEPERIPHERAL NERVE

Blood Supply and theBlood-Nerve Barrier

Physiology of the peripheral nerve

• Excursion

Excursion

• Mesoneurium• Bands of fontana• Epineurium

The cellular response to nerve injury

• The injured nerve must survive• The distal end must create an inviting

environment• The target end organ must be able to receive

the regenerating axon

The Neuronal Responseto Axotomy

Cell support Apoptotic cell death

Macrophage

Glial cell

Target tissue

Neurotrophic factor

Apoptotic cell death

• Sensory neurons• Developing neurons• More proximal lesions

The Neuronal Responseto Axotomy

Formation and progression of the regenerating unit

Proximal unit

Distal environment

Mechanisms of neuronal regeneration

THE CLINICAL EVALUAETION OF NERVE INJURIES: SEDDON AND

SUNDERLAN CLASSIFICATION AND THE MACKINNON MODIFICATION

Six degree injury:neuroma-in-conontinuity

Clinical evaluation

History and examination Electrodiagnostic test

Electrodiagnostic test

Intraoperative NAP

Hour-glass appearance

cable nervegrafts.

rosebudt"e chniquein,

Epineural Versus Fascicular Repair

PRINCIPLES OF NERVE REPAIR

• l. Quantitative assessment• 2. Microsurgical technique• 3. Tension-free repair• 4. Primary repair is performed when feasible.• 5.nerve graft• 6. Postural maneuvers cannot substitute for a• tension-free repairwith grafting• 8. Repair is delayed for a minimum of 3 week• 9. Postoperative early movement• 10. Preoperativep hysicalt herapy

THE CLINICAL CLASSIFICATIONOF NERVE INJURIES: SEDDONAND SUNDERLANDCLASSIFICATIONS AND THEMACKINNON MODIFICATION