Median median anatomy carpal tunnel syndrome.pptx

basic anatomy of the median nerve and its variants. pathology and different theories of the carpal tunnel syndrome plus the variations of the palmar cutanous branch of median nerve. types of skin incision for surgical intervention and difference between endoscopic and microscopic approaches.

1. The Median Nerve and CTS “Anatomy” Mohamed Elsayed Elsebaey , MD Neurosurgery Fellow Benha Teaching Hospital The General Organization for Teaching Hospitals and Institutes (GOTHI)

2. Abductor +add Flexor Opponens pollicis

3. Abductor Flexor Opponens digiti minimi

4. Crosses the brachial artery anteriorly Passes over it. Runs along the medial aspect between the brachialis muscle and the medial intermuscular septum.

5. Median nerve arises from contribution from the lateral and medial cords. M otor filaments come from m edial cord. (Except C7 filaments pronator and flexor carpi radialis come from lateral cord) Sensory filaments pass through the lateral cord.

6. At the Elbow, Median nerve passes under the bicipital aponeurosis ( lacertus fibrosus ) This aponeurosis is radiated ulnarly across the antibrachial fossa.

7. Then enters through pronator teres muscle Usually passes in-between the superficial and deep heads of it. But, May pass deep to the both heads or May also pass through the superficial head. 1

8. 3 – 6 cm above the medial epicondyle, there is bony process called “the supracondylar process” or “ alveolar spur” Fibrous bands called “ ligament of struthers ” are attached between it and the medial epicondyle and producing tunnel. At this point of the bony spur, the median nerve separated from the surrounding vessels and passes inside the tunnel beneath the bony spur. In clinical practice, requiring X ray over the elbow and humerus shows the spur and if related fractures and surgeon correlate those data with clinical examination of the motor power of the fingers, wrist, forearm.

9. X ray of left elbow showing the bony spur and relevant anatomy

10. Then passes between the FDS & FDP Then becoming more superficial in distal forearm.

11. At the level of elbow 4 groups of muscles receive branches from the median nerve. Pronator teres muscle Flexor carpi radialis muscle Palmaris longus muscle Flexor digitorum superficialis muscle

12. Surgical NB. The nerve branch to pronator muscle is: Most proximal. Arising from the anterior surface of Median N proper. Other branches : (FCR, PL, FDS) Deep. Arising from the ulnar side of median N proper AIN About 3 cm distal to the intercondylar line. Arising from the radial side from the median N proper

13. AIN Arises from the radial side from median nerve Innervates Flexor digitorum profundus (FDP) arises from ulnar side of AIN Flexor pollicis L ongus (FPL) arises from radia L side of AIN Pronator quadratus (PQ) From the topographic view, The group of fibres of the AIN is separated long distance before its emerge. It was in ulnar side in Arm, and turns to be radial at level of proximal forearm. Important in issues of nerve transfer

14. What is the clinical significance of identification of nerve topography?? How to use the sural nerve in grafting? How to repair the median nerve ?

15. Palmar cutaneous branch of median nerve

16. Carpal tunnel transverse section

17. Median nerve sensation

18. In 1977 , Lanz et al described 4 categories of median nerve variations Category 1 : variations of the recurrent median N. Category 2 :bifid or duplicated median nerve Category 3 :accessory median nerve passes proximal to the carpal tunnel. Category 4 : 3:accessory median nerve passes distal to the carpal tunnel.

19. In details, Category 1: Recurrent median nerve ( take off ) Extraligamentous Subligamentous Transligamentous Arise from the ulnar side of the median N

20. Extraligamentous distal take off ( radial side of median n)

21. Subligamentous take-off ( radial side of median N)

22. Transligamentous take-off ( radial side of median N)

23. Ulnar side take-off subligamentous

24. Subligamentous take-off Ulnar course Distal emergence Linear horizontal pathway to the thenar muscles The most reliable type for injury

25. Double thenar branches

26. Extra-ligamentous Sub-ligamentous Trans-ligamentous

27. Category 2: Bifid or duplicated median N (High division of median N) Separated by persistent median artery or muscle. When be found , the radial half of the median nerve mostly pass through separate compartment of the carpal tunnel

28. High division of the median nerve with median artery in-between

29. High division of median nerve

30. Category 3 : The accessory median nerve When takes off proximally, Can pass accompanying the median N within the same canal inside the carpal tunnel. Or May perforate the ligament and lie volar to the flexor retinaculum.

31. Anatomical variations of the median N within the carpal tunnel 1995

32. وصلة بين العصب الأوسط و العصب الزندى فى منطقة راحة اليد وصلة ريتش كانييو Riche- cannue motor anastomosis Ulnar to median motor anastomosis in the palm results in preservation of the thenar muscles bulk and contour even if there is severe median N compression or median N injury. And We can suspect it clinically.

33. Riche- Cannieu anastomosis A- between thenar br. Of median N and deep br. Of ulnar N. B- between thenar br. And deep br. Of ulnar N.

34. Carpal tunnel syndrome CTS

35. Facts In 1854 , Dr Paget, was first to describe manifestations of the CTS. In 1924 , Dr Gallowoy did the first release of the CT. Complicated by post Op. pain. Reoperated and was found nerve was adherent to the scar tissue at the incisional line. In 1966 , Dr Phalen publised the largest CTS series study, ( 654 hands) of 439 patients over 17 years.

36. Management Clinical examination Inspection of thenar bulk Motor Sensory Electrophysiology tests Motor latency > 4.5 ms Sensory latency > 3.5 ms Follow up Conservative ttt+ splinting Surgical release Clinical examination as fresh plus Distinguish it is Persistent Recurrent New insult Electrophysiology tests Medico-legal important only Follow up Generally (1,2) is conservative (3) Is surgical Fresh Attacked before

37. Etiology Compression. Impaired nerve blood circulation. ===================================== Sub-synovial connective tissue  fibrosis  compression  nerve ischemia Or Dynamic ischemia of median nerve  certain positions of hand  cause nocturnal paresthesia This group shows rapid recovery after carpal tunnel release.

38. In 2006 , amdio et al concluded that shaking the hands that result in marked relief of the hand symptoms is pathognomonic to CTS . In 2007 , McCabe, suggested that positioning the wrist in neutral position between flexion and extension, in lateral position, in night  relief CTS.

39. CTS is most presented in females and in increased BMI. CTS is strongly related to the repetition, force and vibration. Certain careers: Dental care providers Key boarding using the mouse > 20 h/week Heavy work workers ( claimed that hypertrophied lumbricals that originate from the side of the FDP tendons distal to the TL, causes median nerve compression )

40. In 1973 , Taleisnik described the standard carpal carpal tunnel release surgery. Long curvilinear incision in the palm that extended to the distal one third of forearm. Incision be about 5 mm ulnar to inter-thenar depression to avoid injury of the palmar cutanous branch of median nerve. Cutting the median nerve in the ulnar side preventing scar formation over the median nerve. So avoiding adherence and adhesion and compression over median nerve. Divide the palmar aponeurosis in longitudinal fashion. Distal extent is the (V) point between the thenar and hypo-thenar muscles. If the thenar mm are atrophied, open in meticulous way and search for the recurrent motor branch of median N. Visualization of the median nerve is the insurance of achieving full decompression. Hemostasis. Wound irrigation. Skin closed in simple interrupted way. Finger motion and light hand motion are encouraged. Wrist splint at night for 2-3 weeks to prevent bow shortening and stiffing of the tendons over the median nerve after TL release. Gradual return to the full activity is allowed after 6 weeks from surgery. Internal neurolysis is not recommended at all. In obese patients, use longer skin incisions with zigzag fashion extended proximal to the wrist flexion crease.

41. Prolonged compression  demyelination  axonal loss So, if patients come after 6 months of onset of symptoms, about 4 months are needed for resolving as time of re-myelination .

42. Complications Mild, moderate, severe. Pillar pain : post-op pain located to the thenar and hypothenar areas and is away from the incisional pain and Not well understood. MacKinnon claimed that ulnar based incisions near total free from the pillar pain. Suggested causes of pillar pain: Alteration if the TL Change in position & stability of thenar & htypothenar mm. Edematous origin. Micro-neuroma of the cutaneous branches.

43. If revision surgery needed Must distinguish between Persistent symptoms as pre previous surgery. Recurrence : same previous symptoms with interval of improvement. Added deficit : new symptoms different than pre previous surgery.

44. Causes of complain Incomplete cut of TL. Intraneural scarring Median N. adherent to TL. Median N adherent to incisional scar. PCM injury. Recurrent motor branch injury.

45. References

46. اللهم تقبل عملى كله و ادخلنى مدخل صدق و أخرجنى مخرج صدق اللهم اغفر لى و اعفو عنى و ارحمنى اللهم ارزقنى حسن الخاتمة اللهم ارحم اد/ نبيل حسن , و اغفر له و ارحمه و ارزقه جنه الفردوس و اجعلنى و كل زملائى فى ميزان حسناته