CARPAL TUNNEL SYNDROME

• MC entrapment neuropathy of U/L, compression of median N in carpal tunnel

Anatomy

• fibro osseous canal bound by carpal bones and roofed by transverse carpal ligament
• ligament attached to scaphoid and trapezium radially, hook of hamate on ulnar side
• middle of distal carpal row bones – 10mm – narrowest point
• extends from distal wrist crease to mid palm – 5cm
• contains median N, nine Flexor tendon (FDP, FDS, FPL)
• median N gives of palmar branch to skin of palm and thenar eminence before entering canal – 5cm proximal to wrist – radial side of median n
• in canal branch to radial and ulnar br – radial br gives sensory to palmar surface of thumb and index, motor to APB, FPB(sup.head), Opp pollicis – ulnar br sensory to palmar surface of II, III, radial side of IV fingers

Etiopathogenesis

• increase in carpal tunnel pressure >20-30mm Hg – impedes epineural blood flow – nerve function impaired
• Anatomical factors
  • decreased size of canal
    • bony abnormalities of canal
    • acromegaly
    • flexion/ extension of wrist
  • increased canal contents
    • wrist # (colles, scaphoid)
    • dislocations, subluxations
    • post traumatic arthritis (osteophytes)
    • aberrant muscles
    • local tumors (neuroma, lipoma, ganglion)
    • persistent medial artery
    • hypertrophic synovium
    • hematoma ( hemophilia, anticoagulation therapy)
• Physiological factors
  • neuropathic
    • DM – alcoholism
  • inflammatory
    • RA – gout – infection – nonspecific tenosynovitis
  • fluid balance alterations
    • pregnancy – menopause – ecclampsia – hypothyroidism – renal failure – obesity – long term hemodialysis – SLE – scleroderma – amyloidosis – Paget's disease
  • external factors
    • vibration – external pressure
• in children – macrodactyly, lysosomal storage disorders, family h/o

Clinical features

• numbness (MC) – paraesthesia – pain – burning sensation along median nerve
• increased at night , relieved by hanging down position
• atrophy of thenar muscles, weakness of hand muscles

Clinical tests

• Phalen's test
  • elbow on table – forearm vertical – wrist flexed – 60 sec – numbness and tingling on radial digits
  • sensitive > specific
• Percussion test (Tinel's sign)
  • light tap- proximal to distal – along median N – tingling response in fingers
  • probable CTS if + at wrist
• Durkan's compression test
  • direct compression of median nerve at carpal tunnel – 30sec- paraesthesia
  • most sensitive and specific
• Hand diagram
  • patient marks site of pain and altered sensation on a hand diagram – finds patients perception of symptom
  • markings on palmar side of radial digits
• Hand volume stress test
  • hand volume measured by displacement- repeated after 7 min stress test and 10min rest
  • increase of >/= 10ml
• direct carpal tunnel pressure measurement
  • wick or infusion catheter placed in carpal tunnel – hydrostatic pressure in resting and provocative positioning
  • >25 mm Hg resting pressure
• Reverse Phalen's test (Wormer test)
  • elbow on table – forearm vertical – wrist extension – 60 sec
• Static 2 point discrimination
  • failure to determined minimum 5mm separation – suggest advanced nerve dysfunction
• Moving 2 point discrimination
  • minimal separation of 2 moving points applied to palmar finger tip
  • normal = 4mm. <4mm – severe nerve dysfunction
• Vibrometry
  • vibrometer on palmar side of digit – amplitude at 120Hz – increased to threshold of perception – compare median to ulnar b/l – asymmetry with contralateral hand or median to ulnar asymmetry of same hand
• Semme Weinstein mono filament
  • monofilaments of increased diameter – touched to palmar side of digits – until patient determine which digit is touched
  • nl – 2.83 or less - >2.83 indicates impairment
• Digital sensory latency and conduction velocity
  • orthodromic stimulation and recording across wrist
  • latency >3.5ms or asymmetry of velocity >0.5 m/s to opposite side suggestive
• Motor latency and conduction velocity
  • latency >4.5ms or asymmetry of conduction velocity >1millisec
• EMG
  • fibrillation potential, sharp waves, increased exertional activity
• Imaging
  • X ray at 30⁰ to extended wrist – visualized carpal tunnel
  • CT – bony abnormalities
  • MRI – soft tissue abnormalities
  • USG

Differential diagnosis

• cervical disc herniation
• thoracic outlet syndrome
• pronator syndrome

Treatment

• Non surgical
  • change of work pattern
  • splint
  • cause treatment like RA, DM
  • NSAIDS, diuretics
  • local steroid injections
    • needle entry – slightly proximal to distal wrist crease – ulnar to PL to avoid median N – 1cm radial to FCU to avoid entering Guyon's canal
    • needle 45⁰ – beneath the proximal margin of TCL and directed in line with ring finger – flush of fluid into canal felt distally in mid palm
• Surgical treatment
  • classic approach
  • limited approaches
    • double incision of Wilson
    • minimal incision of Bromleg
  • carpal tunnel tone through small palmar incision – Strickland
  • endoscopic CTS release – single portal(Agee)– double portal (chow)

After treatment

• compression dressing and volar splint
• hand activity as soon as possible
• splint continued for comfort 2.3 wks

Unrelieved and recurrent CTS

• incomplete ligament release
• reformation of flexor retinaculum
  • both needs re exploration and re release of TCL
• fibrosis or painful scar
  • epineurolysis
  • local muscle flaps
  • local or remote free fat grafts
  • excision or Z plasty of scar
  • nerve wrapping or inter position materials (silicone sheet, vein wrap)
• recurrent tenosynovitis
  • tenosynovectomy
  • appropriate medical management ( antibiotics)
• medial or palmar cutaneous neuroma
• double crush syndrome

Order Books Videos Notes and study material shop.orthodnb.com

Orthopaedics made simple for DNB MS MRCS Support and Guidance for DNB Orthopaedics, MS Orthopaedics and Orthopaedic Surgeons. DNB Ortho MS Ortho MRCS Exam Guide Diplomate of National Board.Our site has been helping dnb ortho post graduates since a long time.It has been providing the dnb ortho theory question papers,dnb orthopedics solved question bank, davangere orthopaedic notes, sion orthopedic notes.We provide guidance to post graduates as to how to pass dnb and ms ortho exams, and aspiring orthopaedic surgeons surgical technique teaching videos and orthopaedic books and pdf.

Get updates email orthoguidance@gmail.com whatsapp 9087747888

Orthodnb.com

1. 1. Study Material to Pass Any Orthopaedics Exam
   2. 
      
   1. Davangere Orthopaedic notes pdf
   2. Dawangere Ortho Notes Hard copy all volumes 2017 edition
   3. DNB Solved Question Bank with Answers
   4. Ortho Theory Exam Package
   5. Ortho Practical exam package
   6. Ortho case presentation videos
   7. Orthopaedic Journals
   8. Orthopaedic Physical Examination video Atlas
   9. Sion Hospital Orthopaedic Notes
   10. Orthopaedics Proformas and scheme of practical examination
   11. Orthopaedic instruments videos and extras
   12. Video Atlas of Human Anatomy
   13. Ortho Practical Exam Guide
   14. MRCS Package
   15. Orthopaedic Surgery Technique teaching videos - Trauma
   16. Orthopaedic Surgery Technique teaching videos - Arthroplasty
   17. Orthopaedic Surgery Technique teaching videos - Spine
   18. Orthopaedic Surgery Technique teaching videos - Shoulder Arthroscopy
   19. Orthopaedic Surgery Technique teaching videos - Knee Arthroscopy
   20. Anatomical Approach technique and exposure teaching videos
   21. Orthopaedic PG Course Videos