Perioperative management - Carpal Tunnel Syndrome – Open Carpal Tunnel Release

• persistent sensory and/or motor deficits (hypoesthesia, impairment of stereognosis/2-point discrimination) in D1-D4 with/without thenar atrophy
• relevant and impairing the patient (not improved by conservative measures) painful paresthesias in D1-D4
• in pregnant patients with existing deficits as well as in postpartum persistent CTS

• local or general conditions that surgically or anesthesiologically contraindicate an elective operation or can be improved preoperatively
• for open carpal tunnel release no specific contraindications

• History of typical clinical presentation:
  • Nocturnal burning/sensory disturbance/tingling paresthesias of fingers D1-4
  • Nocturnal/load-dependent numbness of fingers D1-4
  • Improvement by shaking/position change of the hand
• Clinical examination:
  • Inspection/Palpation of radial thenar (M. abd. poll. brevis, M. opponens pollicis, M. flexor poll. brevis Caput profundum) in side comparison, sweat production
  • Testing superficial sensibility by e.g. touching with cotton ball
  • Testing stereognosis by 2-point discrimination, recognition of coins or paper clips
  • Testing motor function with abduction (90° to the hand plane) and opposition, positive bottle sign
  • Provocation tests: Phalen test, Hoffmann-Tinel sign
• Electrophysiological diagnostics (always N. medianus and N. ulnaris bilaterally)
  • Key finding is the reduced nerve conduction velocity of the N. medianus in the carpal tunnel as a result of demyelination: pathological distal motor latency (DML) of the N. medianus > 4.2 ms (with DML of the N. ulnaris < 3.3 ms)
  • pathological sensory nerve conduction velocity (NCV) of the N. medianus < 46.9 m/s, and a difference in the NCV of > 8 m/s compared to the N. ulnaris (limit value 44.6 m/s)
    reduced amplitude of the stimulus response as a result of axonal damage
• Optional additional diagnostics:
  • Imaging diagnostics (X-ray, ultrasound, MRI) only if indication for concomitant diseases (e.g. carpal/tumor)

• no special preparation of the patient necessary
• generally outpatient procedure
• Evaluation of contraindications for bloodless field (e.g., existing shunt in dialysis)

Information about:

• Surgical methods open vs. endoscopic
  • Complication rate for open procedure 2.8 %, for endoscopic procedure 5.6 %
• Extension procedure such as e.g. accompanying tenosynovectomy
• General surgical risks (wound healing disorder)
• Specific surgical risks:
  • Injury to median nerve (risk of complete transection < 0.3 %) with neuropathic
  • pains protracted scar pains (usually subside after 6 months
  • persistent complaints, revision procedure
  • lack of regression of a sensomotor deficit
  • Recurrence risk (increased in patients with rheumatic synovitis and dialysis patients)
  • Wound infection (deep infections < 0.5 %)
  • Tendon/vessel injury (extremely rare < 0.1 %)
  • Functional deficit wrist/hand
  • CRPS (extremely rare)