Peripheral Nerve Injury

1. Peripheral Nerve Injury 同济医院骨外科 黄仕龙

2. General topic introduce definition classification pathological change outcomes diagnosis treatments Specific injury radial nerve median nerve ulnar nerve femoral nerve tibial nerve peroneal nerve Contents

3. What is peripheral nerve? It is a structures which connects central nerve system and terminal orgnas, and transmits electronic potential. Moter nerve Sensory nerve Mixed nerve

6. Functions & Characteristics • Transmit electronic information • Features 1. conductivity 2. reproducibility 3. ....

7. How many? Who are they? 31 pairs • C1-4 cervical plexus • C4-Th1 brachial plexus • Th1-Th12 thoracic nerve • Th2-L4 lumbar plexus • L4-S5 sacral plexus：

8. Classification • Neuropraxia • Axonotmesis • neurotmesis

9. Histopathological change • Neuropraxia • Most minor damage, such as slight tension… • Appearance is intact, may have cell or molecular change; • Lose conductivity temporary; A movement disorder, but without atrophy; B sensory disorder, but still exist; C with biological potential

10. histopathological change • Axonotmesis medium damage, such as contusion.. • Appearence: looks good, bead-shape, or hollow feeling; • Histological: epineurium intact, but fiber rupture, or tract damage with inner haemorrhagia and scar; • Lose moter, sensory, and electronic reaction.

11. Histopathological change • Neurotmesis • Severe damage, such as shape damage, avulsion.. • Continuity was totally broken; • Without any moter, sensory, vegetative nervous reaction, muscle begin atrophy; • Without any potential.

12. Pathological outcome During w1-w4： • Wallerians’ Degeneration: axon & myelin sheath shrinking, smash, broken. Then Macrophage coming... • Schwann’s effect: rest Schwann’s cell proliferation, form hollow pipe, then new axons coming.

14. Results Repair timely and properly • 2-3w, axon regenerate • 4w, get through new Schwann’s membrane pipe • NGF, E. stimulation induce the axon heading to terminal organs • 1mm per day

15. Results • Repair too late or improperly • pressure, scar or poor blood supply • impede axon growth • >6w, Schwann’s membrane smash to pieces • Endplate degeneration and disappear, muscle atrophy; • nonreversible

16. Diagnosis • History: • Symptom： ①movement dysfunction; ②sensory disfuction ; ③vegetative nervous dysfuction; • Tinel sign • Electrophysiologic study (EPS)

17. Movement dysfunction • active movement • myodynamia

18. Sensory disfuction • Lose algesia, thermal sense, pselaphesia • How to test: use a pin: healthyside first, then the wounded side use some soft subjects, such as cotton swab; use cold water(5-10℃), or warm water(40-45 ℃); feel different shape when blindly;twopoint discrimination test; normally 2-4mm

20. Vegetative nervous dysfuction • Skin: smooth, adiapneustia; • Iodostarch reaction: • Nail: cracking

21. Tinel’s test • Use finger or small hammer • Over inductance means N. regeneration. • Positive site

22. Electrophysiologic study(EPS) • Normal action potential: 40～70m/sec • fibrillation potential(2～4w): om/sec

23. Treatments • strategies of treatment Diagnose properly Operate early

24. Treatments Neuropraxia or closed Axonotmesis • Conservative Treatment for 3m; • Physiotherapy; • acusector; • Nerve growth factor

25. Treatments Neuropraxia or closed Axonotmesis • >3m without recover or improve • Nerve relieve or neurolysis

27. Treatments Opening Neroirgure Gompletly • 1. primary repair: immediately; • 2.Extension repair: during w1-w3; • 3.Secondary repair: during m1-m2; • 4.Delayed repair: poor outcome

28. Treatments Operational construction • 1. neurorrhaphy • ①end-to-end anastomosis • ②end-to-side anastomosis • 2. Nerve Brisement • 3. nerve grafting • 4. nerve implantation

36. Treatments Deal with Neurolesion • 1. Dissociate proximal and distal(<5cm); • 2. Flax the joint; • 3. Neural inversion; • 4. Remove some bone; • 5. Transplantation; • 6. gap bridging; • 7. replacement.

41. Specific topic

42. Median nerve injury • Constitution: • Innervated: nearly all flexor of forearm; • Injure at wrist: Ape hand deformity,.. • At elbow: flexor of thumb, index, middle finger; • At upper arm:

44. Ulnar nerve injury Constitution: Innervated: flexor of ring finger and little finger Injure at wrist: clawhand deformity, intrinsic muscle atrophy.. At elbow: flexor of ring finger, little finger;

46. Radial nerve injury Constitution: superficial & deep branch Innervated: all extensor Injure at wrist: Tucks area, At elbow: extensor of finger At upper arm: extensor of wrist

49. Femoral nerve injury Constitution: L2，3，4 Innervated: quadriceps femoris, sartorius Injure: knee extension dysfunction

50. Tibial nerve injury Constitution: come from sciatic nerve; anterior & posterior branch Innervated: all flexor of ankle, sense of the sole Injure at thigh: most common caused by supracondylar fracture of femur;