بســـم الله الرحمن الرحيم

1. بســـم الله الرحمن الرحيم

2. HazemHantira,FRCSEd.Consultant Orth.SurgeryAdan Hospitalhhantira@hotmail.com

3. PERIPHERAL NERVE INJURY

4. Objectives Anatomy of peripheral nerve Causes Types Pathological changes Clinical effect/ Diagnosis Principles of management The future???

5. ANATOMY • Peripheral nerves are bundles of axons conducting afferent & efferent impulses. • Each group (bundle) of axons is called fascicle. • Each axon is elongated process of a nerve cell (Neuron). • Cell bodies of • Motor neuron – Ant horn cell • Sensory neuron – dorsal root ganglia. • Single neuron may supply 10 – 1000 fibres.

6. ANATOMYNerve Cell (neuron)

7. ANATOMYNerve Fiber

8. Myelinated All motor axons Large sensory axons : (touch, pain, proprioception) Nodes of Ranvier Faster conduction Unmyelinated Small diameter (crude touch ) Efferent sympathetic No nodes Slower conduction ANATOMY (Types of Nerve Fibers)

9. ANATOMY (Nerve Sheath) • Endoneurium – covers axon. • Perineurium – covers fascicles • Epineurium – covers nerve trunk

10. MODE OF NERVE INJURY • Ischemia • Compression • Traction • Laceration • Burn.

11. Classification of Nerve IjuriesSEDDON CLASSIFICATION

12. Classification of Nerve Injuries SUNDERLAND CLASSIFICATION

13. Sunderland.s classification Although Sunderland.s classification provides a concise and anatomic description of nerve injury, the clinical utility of this system is debatable. Many injuries cannot be classified into a single grade. Mixed nerve injuries, in which all fibers are affected but to varying degrees, are common among peripheral nerve injuries.

14. Sunderland’s clssification Furthermore, although Sunderland.s classification accurately describes the pathoanatomy of nerve injury, it is seldom possible to accurately subclassify an axonotmetic nerve injury on the basis of preoperative clinical and electromyographic data. The subtype is usually discernible only by histologic examination of the injured nerve

15. Wallerian degeneration Wallerian degeneration (i.e., breakdown of the axon distal to the site of injury) is initiated 48 to 96 hours after transection. breakdown of myelin begins, and the axon becomes disorganized. Schwann cells proliferate and phagocytose myelin and axonal debris .

16. PathophysiologyNERVE INJURY HEALING

18. CLINICAL FEATURES • High index of suspicion.(neuro.exam.of every Fx.) • Symptoms • Numbness • Paraesthesia,? loss of sensation • Muscle weakness, ?paralysis • Signs • Abnormal posture .eg.:wrist drop • Weakness • Loss of sensation • Sudomotor changes

19. ASSESSMENT • Degree of injury • Tinel’s sign (advancing at rate of 1 mm\day) • EMG • Denervation potential at 3 weeks • Does not distinguish between axonotmesis and neurontemesis.

20. ASSESSMENT • Level of function • Sensory • Two point discrimination (innervation density) • Motor • Medical Research Council Scale (0-5 grades)

21. Clinical effects of nerve injury After injury (short of transection), function fails sequentially in the following order: motor, proprioception, touch, temperature, pain, and sympathetic. Recovery occurs sequentially in the reverse order

22. Clinical effects of denervation After denervation, distal structures undergo many changes. In major peripheral nerve injuries, such as brachial plexus palsy, bone develops disuse osteoporosis, and joints and soft tissues become fibrotic and stiff.

23. Clinical effects of denervation . Muscle: atrophies and undergoes interstitial fibrosis but remains viable for at least 2 years . Bones: disuse osteoporosis . Joints: fibrosis and stiffness

24. TREATMENT(preop.) • Expectant • Dynamic splints to avoid contracture • Passive manipulation to avoid stiffness • Direct galvanic stimulation(?) reduces muscle atrophy • Pool therapy can be helpful to improve joint contractures

25. TREATMENT (operation) Nerve Exploration • Indications • Type of injury suggest that nerve is divided. • If recovery is delayed • Vascular injury, unstable fracture, contaminated soft tissue, and tendon injury are treated before nerve injury.

26. TREATMENT Primary Repair • Sooner the better. • Ragged ends –pared. • Use microscope and 9\0 suture. Nylon, • Fibrin glue.?? • Suture epineurium. • Fascicular repair. ?? • Avoid tension on suture line. • Postop.Splinting.

27. TREATMENT Delayed Repair • Indications • Closed injury not improving at expected time • Late presentation and missed diagnosis • Failed primary repair • Nerve Explored – scarred segment resected -nerve mobilized –transposition (if req.) - graft (if req.).

28. TREATMENT Nerve Grafting • Used to bridge gaps. • Sural nerve most commonly used. (single\cable). • Other donors: lat.cut.n. of the thigh, superficial sensory br. of radial n. • Reverse direction? • Vascularised grafts also used.

29. TREATMENT Nerve Transfer • Indicated for root avulsions of brachial plexus. • Spinal accessory to suprascapular nerve. • Intercostal nerves to musculocutaneous nerve.

30. TREATMENT Tendon Transfer • Motor end plate must have degenerated (i.e. 18 – 24 months after injury) • Assess • Muscles – lost • Muscles – available • Donor Muscle • Expandable • Adequate power • Synergistic • Transferred tendon • Routed subcutaneously • Straight pull

31. PROGNOSIS DEPENDS ON • TYPE OF LESION • LEVEL OF LESION (proximal vs distal). • TYPE OF NERVE,( purely motor n.gives better result than mixed nerve.) • SIZE OF GAP • AGE (younger pts. give better results). • DELAY IN SUTURE • ASSOCIATED LESION • SURGICAL SKILL

32. The future? Use of neurotrphic and neuritogenic drugs to enhance survival and maintainance of n.fibres Use of immune system modulators to decrease fibrosis. Use of enhancing factors e.g. nerve growth factor . Entubulation chambers (silicon- Gore-tex.) to serve as conduit for loosely approximated nerve endings.

33. Clinical ExaminationSpecific Peripheral Nerves

34. Clinical ExaminationSpecific Nerve Roots

35. Peripheral Nerve Injuries Axillary nerve

36. Anatomy Median Nerve

37. Peripheral Nerve Injuries Median nervePointing Index

38. Anatomy Ulnar nerve

39. Peripheral Nerve Injuries Ulnar nerveClaw Hand

40. Anatomy Radial nerve

41. Anatomy Radial nerve

42. Peripheral Nerve Injuries Radial nerveWrist Drop

43. Femoral nerve

44. Obturatornerve

45. Anatomy Sciatic nerve

46. Anatomy Tibial nerve

47. Anatomy Common peroneal nerve

48. Peripheral Nerve Injuries Sciatic nerve Foot drop

49. THANK YOU!!!!