A small presentation on the scenarios leading to acute CTS

1. Acute Carpal Tunnel
Syndrome
Prepared by Dr Madan Mohan ;
Based on Orthop Clin N Am 43 (2012) 459–465

2. Anatomy……..
• The carpal tunnel is an hourglass-shaped conduit through which nine
flexor tendons and the median nerve traverse to gain entry into the
hand.
• The inlet of the carpal tunnel can be approximated by the volar wrist
crease and the outlet is marked by Kaplan’s cardinal line.
• The width of the tunnel proximally and distally is roughly 25 mm, the
depth has been measured at 12 to 13 mm and the volume is 5 ml

3. • The TCL is suspended from the scaphoid and trapezium
radially and the hamate and pisiform ulnarly.
• Just deep to the TCL, the most superficial structure is the
median nerve, which usually courses just radial to the
midline.
• The remaining contents of the canal include the four
tendons of flexor digitorum superficialis and the four
tendons of the flexor digitorum profundus, which are
encapsulated by the ulnar bursa, and the flexor pollicis
longus, which is encapsulated in the radial bursa

4. • The carpal tunnel behaves like a closed compartment, because
the circumferential bony and ligamentous architecture are
unyielding and further bounded by occlusive synovial tissue at
the entry and exit.
• As the pressures increase to a threshold level, perfusion of the
epineurium decreases and this causes ischemia.
• Tissue ischemia leads to nerve conduction block, endoneurial
edema, and dysfunction of axonal transport, which manifest as
the classic symptoms along the median nerve territory

5. Etiologies of Acute CTS

6. Traumatic Causes
• Distal radius fracture
• Metacarpal fracture
• Carpal bone fracture
• Scaphoid dislocation
• Lunate dislocation
• Perilunate dislocation
• High-pressure injection
• Laceration
• Animal bite

7. Infective Causes
• Infectious tenosynovitis
• Septic arthritis
• Cellulitis
• Filarial infection
• Metacarpal osteomyelitis
• Parvovirus
• Toxic shock syndrome
• Intracarpal canal sepsis
• Leprosy

8. Inflammatory Causes
•Excessive overuse (flexor synovitis)
•Pseudogout
•Gout
•Calcifying tendinitis
•Hydroxyapatite deposition
•Alendronic acid deposition
•Rheumatoid arthritis

9. Tumours
•Giant cell tumor
•Hemangioma
•Myxofibrosarcoma

10. Coagulopathy
•Hemophilia
•von Willebrand disease
•Warfarin

11. Iatrogenic Causes
•Surgical hematoma
•Hyperflexion after external fixation
•Cotton-Loder position
•Tumescent fluid

12. Fluid Shift
•Burns
•Stonefish toxin
•Snake venom
•Pregnancy
•Pancreas transplant

13. Aberrant Anatomy
•Anomalous lumbricals
•Median artery thrombosis
•Median artery aneurysm
•Median artery rupture
•Venous malformation

14. Diagnosis
•In general, the diagnosis of ACTS is a clinical one
•The onset of symptoms is on the order of hours
to days following an initiating event.
•Patients will complain of pain and numbness
over the median nerve distribution, and
progressive stages may reveal weakness, which
can be tested by the strength of the abductor
pollicis brevis muscle

15. Diagnosis……
• Two-point discrimination is probably the most useful
physical examination maneuver.
• Mack and colleagues defined an abnormal distance as
greater than 15 mm.
• Bauman and colleagues noted that patients initially
were able to distinguish two points less than 6 mm
but, by 6 to 12 hours, those with ACTS could not
discriminate points greater than 20 mm.

16. Pressure Monitoring
• In patients with objective sensory deficits, a trial of conservative
management is reasonable.
• If relief is not provided after 2 hours following reduction, splinting, and
elevation, then intracarpal pressure monitoring can be considered.
• The technique involves introduction of a wick catheter into the carpal
tunnel via a starting point 1 cm proximal to the distal wrist crease.
• The needle is directed at a 45 degree angle heading distally, advanced until
the bony carpus is engaged, and then drawn back 0.5 cm.
• A normal individual measures approximately 1 to 4 mm Hg with the wrist in
neutral position; flexion or extension will elevate the measurement

17. Lundborg and colleagues40
described a critical threshold of 40
mm Hg—above which nerve ischemia
is imminent. In a subsequent study,
Szabo and colleagues also
suggested median nerve damage was
a function of ischemia, which
occurred when canal pressures
were within 30 mm Hg of the
diastolic blood pressure

18. Algorithm for management of acute median
neuropathy

19. Management…….
•Open decompression of the carpal tunnel is
the treatment of choice for ACTS
•Atraumatic cases should also be treated
with appropriate medical management

20. • Management of bleeding diatheses is controversial:
hemophiliacs are traditionally given a trial of
conservative management, including factor VIII
replacement, splinting, and elevation.
• The optimal observation time is unknown, and it
seems that surgery is generally required to resolve the
symptoms.
• Other bleeding conditions, such as warfarin therapy or
von Willebrand disease, have been successfully
managed surgically without the addition of clotting
factors, vitamin K, or fresh frozen plasma

21. •ACTS secondary to inflammatory disorders or
mineral deposits may benefit from a
tenosynovectomy, in addition to releasing the
TCL, and soft tissue masses should be sent for
open biopsy.
•Infectious causes may require multiple
irrigations and debridements, and the wound is
usually left partially open to drain