Etiology, pathogenesis and management of this nerve compression syndrome described in this presentation.

1. CARPAL TUNNEL SYNDROME
DR G AVINASH RAO
FELLOW HAND AND MICROSURGERY
DEPARTMENT OF PLASTIC SURGERY, SKIMS ,
SRINAGAR

2. INTRODUCTION
 Carpal tunnel syndrome– most common
compressive neuropathy of upper extremity.
 Symptoms of median nerve compression–
were first described (distal radius fractures) by
Sir James Paget in 1854.
 The term carpal tunnel--- coined—Mersch
8 decades later.

3. Anatomy
 Carpal tunnel is bordered dorsally by concave
arch of carpus & volarly by transverse carpal
ligament (TCL).
 10 structures pass--- 9 flexor tendons &
median nerve.
 Median nerve is most superficial structure,
entering just radial to midline.

6. Recurrent motor branch.
 It usually originates in extraligamentous
position distal to TCL.
 Extraligamentous (46%)
 Subligamentous(31%)
 Transligamentous (23%)

7. The PALMAR CUTANEOUS BRANCH OF THE MEDIAN
NERVE lies between the FCR and PL tendons in the distal
forearm, but its branches may be found upto 6mm ulnar
to the thenar crease in the palm.

8. ETIOLOGY
Idiopathic
Women > men (2-3:1)
Age – 30-60 (MC)
Use of vibrating hand tools, smokers,
High body mass index (BMI) – obesity.
Wrist ratio – If the anterior to posterior distance is ≥70% of the
medial to lateral distance, there is a significant association with
idiopathic CTS.
Pregnant women – Symptoms relieve after Delivery,
Children – Rare (macrodactyly, lysosomal storage disorders, strong
family history – predisposes).

9.  Trauma caused by repetitive hand motions
especially in works requiring repeatetive
forceful finger and wrist flexion and extension.
 Habitual sleeping posture in which the wrist is
kept acutely flexed.

10. FACTORS INVOLVED IN PATHOGENESIS
OF CTS. Kerwin G, Williams CS, Seiler JG: The pathophysiology of
carpal tunnel syndrome, Hand Clin 12:243, 1996.

11. Pathogenesis
 Median nerve is susceptible to compression
within carpal canal because of unyielding fibro
osseous borders.
 Normal pressure--- 2.5mm Hg.
 Elevation of carpal tunnel pressures impedes
epineurial blood flow, and nerve function is
impaired
 A decrease in epineural blood flow &
edematous changes occur--- pressure reaches
20-30 mm Hg.
 At > 30 mm Hg, nerve conduction diminishes,

12. Diagnosis of CTS
 History & physical examination are the key.
 CTS is primarily a clinical Diagnosis.
 Pain (nocturnal > day) , deep aching/throbbing
 Numbness , tingling and Paresthesia in typical
median nerve distribution.
 Daytime paresthesias– elicited with activities
involving prolonged wrist flexion/ extension.
 Shaking & Exercises--- sometimes REDUCE
symptoms.
 B/L CTS - Check opposite hand for early
diagnosis
 Atypical presentation– paresthesias in radial digits

13. CHRONIC CTS
 Chronic median nerve compression--- gritty or
numb sensation in fingers.
 grip & pinch weakness, &
 diminished finger dexterity with H/o dropping
objects (Prominent Thenar wasting).
 RSD/ CRPS.

14. Clinical Evaluation
 Thorough physical examination--- including
cervical spine & entire upper extremities.
(Double crush phenomenon)
 Soft tissues are assessed for skin & muscle
atrophy.
 Cold intolerance, dryness & unusual textures
in radial digits signify disruption of sympathetic
fibres carried by median nerve.

15. TINEL’S SIGN (NERVE
PERCUSSION)

16. Tinel’s sign
The examiner taps directly over the carpal
tunnel with his or her long and index
fingers.
A positive test consists of paresthesia or pain
in a median nerve distribution.

17. Phalen’s test
The patient’s wrist is held in a flexed position
for upto a minute or until onset of symptoms.
A positive test consists of the onset of
numbness or paraesthesia in the median
nerve distribution.

19. Carpal tunnel compression test
/ Durcan’s Test
The examiner applies direct pressure to the carpal
tunnel with his or her thumb for upto 1minute or until
onset of symptoms. A positive test consists of the onset
of numbness or paresthesia in the median nerve
distribution.
More specific (90%) and more sensitive (87%) than either
the Tinel or Phalen test.

20. Semmes-Weinstein
monofilaments

21. Semmes-Weinstein
monofilaments
 Monofilament evaluator size was started from
2.83 to 6.65.
 2.83 – Green – Normal
 3.61 – Blue – Diminished light touch
 4.32 – Purple – Diminished protective
sensation
 4.56 – Red – Loss of protective
sensation

22. Two-point discrimination

23. Two-point discrimination
 STATIC
• Determine minimal separation of two distinct points
when applied to palmar fingertip
• Innervation density of slow-adapting fibers
• Failure to determine separation of at least 5 mm
 DYNAMIC
• As above, with movement of the points
• Innervation density of fast-adapting fibers
• Failure to determine separation at least 4 mm
BOTH INDICATE ADVANCED NERVE

24. Katz & Stirrat hand diagram
Ryan P. Calfee, MD, Ann Marie Dale, PhD, Daniel Ryan, MS, Alexis Descatha, MD,
Alfred Franzblau, MD, Bradley Evanoff, MD

26.  The MOST SENSITIVE TESTS - Durkan nerve
compression, the hand diagram score, night
pain, and Semmes-Weinstein testing after a
Phalen test.
 The MOST SPECIFIC TESTS were the hand
diagram and Tinel sign.

27. GRAHAM B’S CTS – 6
CRITERIA

30.  Szabo et al determined a probability of 0.86 in
correctly diagnosing CTS in presence of
positive median nerve compression test,
positive hand diagram, night pain, & abnormal
Semmes-Weinstein monofilament testing.

31. NCS & EMG
 It tells weather pt has the disease
 It is useful to judge severity of disease
 Prognostic value after treatment
 If NCS shows axonal loss then surgery has to be
advised.
 Diagnose incomplete release or Iatrogenic Nerve
injury
 Double crush syndrome (cervical myelopathy /
pronator syndrome)
 Medicolegal issues
 If pt has obvious thenar muscle wasting.

32. NCS &EMG
 According to the American Association of Electrodiagnostic
Medicine recommendations:
 Median nerve distal sensory latency, upper limit of
normal – 3.6 ms
 Difference between the median and ulnar nerve distal
sensory latencies, upper limit of normal – 0.4 ms
 Distal motor latency over the thenar, upper limit of
normal – 4.3 ms
 Median motor nerve conduction velocity – lower limit of
normal – 49 m/s
 Median sensory nerve conduction velocity – lower limit
– 49 m/s

33. SONOGRAPHY
 Non invasive
 Presence of median nerve edema
 Measurements of cross-sectional area of median nerve at carpal tunnel
inlet proximally and outlet distally were taken
 The shape, size, echogenecity and relationship of median nerve to
overlying retinaculum
 Amount of synovial fluid and any presence of masses (cysts /lumps)
 Anatomy of median nerve and continuity
 Considered in reccurent cases (not routinely done)

34. MEASUREMENT OF CSA OF THE MEDIAN NERVE

35.  The cut-off value for pathological cross-
sectional area of median nerve is 9.4 mm
square.
 Mild – 9.4 to 11.3
 Moderate –11.3 to 13.5
 Severe – 13.5 and above

36. OTHER INVETIGATIONS
 Imaging studies
Three-view radiographs of the wrist
(posteroanterior, lateral, oblique) plus carpal tunnel
view: obtained when there is antecedent wrist trauma.
MRI (diffusion tensor imaging) - not routinely used for
diagnosis. A major advantage of MRI is its high soft-
tissue contrast, which gives detailed images of bones
and soft tissues.
 Serologic studies
No blood tests specifically support diagnosis of CTS
Diabetes & Hypothyroidism are common diseases---
FBS & Thyroid function test.

37. AAOS GUIDELINES – for Non Sx
Rx
 Considered in early CTS.
 Trial of conservative Rx for 2-7weeks if it fails,
attempt one more time.
 Local Sterid and splint recommended prior to
surgery
 Neurotonics – Placebo affect
 Massage / acupunture /any other conservative
options not recommended

38. Kaplan, Glickel, and Eaton - five important factors
in determining the success of nonoperative
treatment:
(1) age older than 50 years,
(2) duration longer than 10 months,
(3) constant paresthesia,
(4) stenosing flexor tenosynovitis,
(5) a positive Phalen test result in less than 30
seconds.
0 - Two thirds of patients were cured by medical treatment
1 - 59.6% were cured.
2 - 83.3% when two factors were noted
3 - 93.2% did not experience any improvement
No patient with four or five factors was cured by medical
management.

39. Treatment – Conservative
options
 Nerve Gliding Exercises.
 Local Triamcinolone (steroid) Injection
 Night Splints.
 Strict control of medical illness
 Treatment of double crush syndrome
 contraversial
Oral medications
Diuretics, NSAIDs, oral corticosteroids & vitamin B6.--- thought to decrease
interstitial fluid pressure within carpal canal.

40.  Celiker et al compared the effectiveness of
NSAIDs & splinting with corticosteriods
injections in treating CTS.
 Found that both methods of treatment led to
statistically significant improvement in
symptoms at 2 months.

41.  Aufiero et al cited several studies supporting &
disproving the efficacy of vit B6.
 Only 2 studies were randomized & blinded in
design--- no improvement.

42. Corticosteroid injection
 Gelberman et al found single injection
improved CTS symptoms in 76% of pts after 6
weeks.
 However only 22 % remained symptom free at
1 year.
 Effective in mild CTS symptoms,< 1
year,normal sensibilty testing & only minor
electrodiagnostic study abnormalities.

43.  Transient elevation in blood glucose can be
anticipated--- thus a less soluble corticosteroid
preparation (triamcinolone).
 Diabetic pts should be instructed to monitor
their serum glucose.
 No absolute contradiction to injection during
third trimester of uncomplicated pregnancy or
healthy breast feeding woman.

44.  Immobilization of wrist at night & intermittently
during the day.
 Pressure in carpal tunnel is lowest with wrist in
2* -/+ 9* of extension & 2* +/- 6* of ulnar
deviation.
Splinting

45. Ultrasound Therapy
 In randomized study ultrasound improved
symptoms at 2 weeks, 7 weeks, 6 months.
 However another study demonstrated no
appreciable benefit at 2 weeks from this form
of treatment.

46. Ergonomics
 Ergonomic changes---specialized desk chairs
& computer keyboard proved to prevent CTS.

47. Exercises
 Nerve & tendon gliding exercises enhance
venous blood flow & decrease pressure within
carpal tunnel.
 Rozmaryn et al evaluated 240 pts with CTS,
half of whom were instructed to perform nerve
& tendon gliding exercises.
 Patients who did not do these exercises, 71
% eventually underwent carpal tunnel release
surgery, in other group 43% had surgery.

48. AAOS GUIDELINES- for Sx
Rx
 Regardless of technique used – complete
release of Flexor Retinaculum is
recommended
 Epineurotomy , Neurolysis, Tenosynovectomy
are not recommended in all cases
 Wrist immobilization is not required

49. Surgical treatment - Options
 OPEN CTS RELEASE
 MINI OPEN CTS RELEASE
 ENDOSCOPIC CTS RELEASE
- SINGLE PORTAL (AGEE)
- TWO PORTAL (CHOW)

50. OPEN CTS

51. OPEN CTS RELEASE
 The palmar incisions should be well ulnar.
 A curved incision ulnar and parallel to the thenar
crease but the palmar cutaneous branch of the
median nerve proximally may be more at risk of
injury.
 Maintain longitudinal orientation so that the incision is
generally to the radial border of the ring - fourth ray.
 Incise and reflect the skin and subcutaneous tissue.
 Identify the palmar fascia from the wrist flexion crease
distally.

52. And the distal forearm antebrachial fascia proximally by
subcutaneous blunt dissection.
Split the palmar fascia and expose the underlying transverse
carpal ligament and carefully divide it and avoid damage to the
median nerve and its recurrent branch
Fibers of the transverse carpal ligament can extend distally
farther than expected. The flexor retinaculum includes the distal
deep fascia of the forearm proximally, the transverse carpal
ligament, and the aponeurosis between the thenar and
hypothenar muscles.
A successful carpal tunnel release usually requires division of all

53. MINI OPEN CTS INCISION

54.  Mark surgical incision with a skin pen
 The longitudinal incision - just distal to the distal wrist
flexion crease and slightly ulnar to the midline of the
wrist.
 Extend Distally - 2.0 to 3.0 cm in line with the third
web space.
 Expose the transverse carpal ligament - by splitting
the parallel palmar fascia fibers and retract
hypothenar fat ulnarly.
 Intrinsic muscles obscure the midline of the TCL and
can be released from their origin and reflected away

55.  Carefully open the carpel tunnel by division of
the TCL with a no15 blade. Ensure complete
release.
 The TCL divided in such a way that 3 to 4 mm
of it is left attached to the hamate hook to
avoid flexor tendon ulnar subluxation.
 Make sure the contents of the carpal tunnel
are not adherent to the undersurface of the
TCL.
 Close the incision in routine fashion and apply
a compressive dressing.

56. Endoscopic carpal tunnel
release
Problems related to endoscopic carpal tunnel
release include
(1) a technically demanding procedure;
(2) a limited visual field that prevents inspection
of other structures;
(3) The vulnerability of the median nerve, flexor
tendons, and superficial palmar arterial arch;
(4) The inability to control bleeding easily;
(5) The limitations imposed by mechanical
failure.

57. Agee, McCarroll, and North - 10 guidelines for the
single-incision ECTR
1. Know the anatomy.
2. Never over commit to the procedure.
3. Ascertain that the equipment is working properly.
4. If scope insertion is obstructed, abort the procedure.
5. Ascertain that the blade assembly is in the carpal
tunnel and not in the Guyon canal.
6. If a clear view cannot be obtained, abort the
procedure.
7. Do not explore the carpal canal with the scope
8. If the view is not normal, abort the procedure.
9. Stay in line with the ring finger.
10. When in doubt, get out.

58. CONTRAINDICATIONS FOR ECTR (DESCRIBED
BY CHOW)
(1) The patient requires neurolysis,
tenosynovectomy, Z-plasty of the transverse
carpal ligament, or decompression of the
Guyon canal.
(2) The surgeon suspects a space-occupying
lesion or other severe abnormality of the
muscles, tendons, or vessels in the carpal
tunnel.
(3) The patient has localized infection or severe
hand edema, or the vascular status of the
upper extremities is tenuous.

59. Fischer and Hastings further added
(1) Revision surgery for unresolved or recurrent
carpal tunnel syndrome
(2) Anatomic variation in the median nerve.
(3) Previous tendon surgery or flexor injury that
would cause scarring in the carpal tunnel.
(4) Limitation of wrist extension is (endoscopic
instruments cannot be introduced into the
carpal tunnel).
AS CONTRAINDICATIONS FOR ECTR.

60. AZEE TECHNIQUE

61. AZEE

62. CHOW TECHNIQUE

64. Open vs endoscopic
 Open vs endoscopic
Endoscopic– shorten recovery time
 However no substantial differences in final
outcome.
 One study in 25 pts, one hand open & another
endoscopic was done 3 months later, no
significant differences
 With ECTR - Less palmar scarring and ulnar
“pillar” pain, rapid and complete return of
strength, and return to work and activities at
least 2 weeks earlier.

65. Post-OP Rehabilitation
 Wrist immobilisation after carpal tunnel
surgery--- no benefit in pain relief or surgical
outcome.
 Active motion exercises of wrist & fingers are
to be encouraged.

66. SURGICAL COMPLICATIONS
 Median nerve injury.
 Hypertrophic scar formation.
 Pillar pain.
 Injury to superficial arterial arch.
 Incomplete release of TCL.
 Tendon adhesions.
 Infections.
 Wound hematoma.
 Finger stiffness.
 Recurrence.

67. ECTR COMPLICATIONS
 Intraoperative injury to flexor tendons.
 Injury to median, ulnar, and digital nerves.
 Injury to superficial palmar arterial arch.
ECTR -Technically demanding procedure

68.  Young pt with symptoms of CTS and decreased
grip stength consider – CTS release + Flexor
Tenosynovectomy.
 If symptoms persists in previously operated case
(tingling and Paresthesia with Tinels positive) –
Consider sonography - incomplete release /
Neuroma in continuity formation 20 to iatrogenic
injury
 Elderly with chronic CTS and thenar wasting and
inability to do finer activities – consider CTS with
Tendon Transfer for thumb opposition
(opponensplasty)
Considerations before Sx

69. UNCOMMON – REQUIRE
ATTENTION
BE AWARE OF POTENTIAL ANOMALIES:
 connections between the FPL and the index
FDP tendon;
 Anomalous FDS;PL, hypothenar, lumbrical
muscle bellies;
 Median and Ulnar nerve branches and
interconnections.
 RARE – BIFID MEDIAN NERVE

70. Summary
 CTS– common problem.
 Several risk factor are associated.
 Thorough history & physical examination is the
key.
 Non-surgical & surgical techniques are
beneficial.
 Both open & endoscopic have same results.
 Look for S/O CRPS (RSD) in Chronic cases,
Before surgery.