Carpal Tunnel

• Treatment can be nonoperative or operative, and should be based on the following:
  • Nonoperative treatment
    • Night splints and injection of cortisone preparations
    • Five important factors in determining success:
      • Age over 50 years
      • Duration longer than 10 months
      • Constant paresthesia
      • Stenosing flexor tenosynovitis
      • Positive Phalen test result in less than 30 seconds.
    • Cure rate with medical therapy:
      • 0 factors: 66%
      • 1 factor: 60%
      • 2 factors: 20%
      • 3 factors: 10%
      • 4-5 factors: 0%
  • If symptoms are mild and there is no thenar muscle atrophy, medical therapy can be attempted
• Operative management
  • If signs and symptoms are persistent and progressive, especially if they include thenar atrophy, operative management is indicated.

• No specific contraindications to open release
• Contraindications for endoscopic surgery include:
  • Need for neurolysis, tenosynovectomy, Z-plasty of the transverse carpal ligament, or decompression of Guyon's canal
  • Space-occupying lesion or other severe abnormality of the muscles, tendons, or vessels in the carpal tunnel.
  • Infection or severe hand edema
  • Tenuous vascular status of the upper extremities
  • Revision surgery for unresolved or recurrent carpal tunnel syndrome
  • Significant anatomical variation in the median nerve
    • This is suggested by clinical findings of wasting in the abductor pollicis brevis muscle without significant median sensory changes.
  • Previous tendon surgery or flexor injury
    • This causes scarring in the carpal tunnel, preventing the safe placement of the instruments for endoscopic carpal tunnel release.

• Standard hand set
• Open procedure
  • Blunt dissector, such as a McDonald dissector
• Agee single-portal technique
  • MicroAire Carpal Tunnel Release System
    • Includes synovial elevator and several hamate finders
  • Ragnell right-angle retractors
  • Tenotomy scissors
• Chow two-portal technique
  • ECTRA System
    • 4.0 mm × 30± endoscope
    • Slotted cannula
    • Rigid obturator
    • Curved blunt dissector
    • Self-retaining retractor
    • Hand holder
    • Probe
    • Palmar arch suppressor ("Chow catcher")
  • ECTRA Disposable Kit
    • Probe knife
    • Retrograde knife
    • Triangle knife
    • Hand pad

• Boundaries of carpal tunnel:
  • Dorsal: transverse arch of the carpal bones
  • Ventral: flexor retinaculum, with three components: deep forearm fascia (most proximal), transverse carpal ligament (TCL) (over the wrist) and distal aponeurosis between thenar and hypothenar muscles (most distal)
    • Flexor retinaculum attachments:
      • Medial: pisiform and hook of hamate
      • Lateral: scaphoid tubercle and trapezium at the beak and body
  • Medial (ulnar): hook of hamate, triquetrum, pisiform
  • Lateral: scaphoid, trapezium, fibroosseous flexor carpi radialis (FCR) sheath
• Once through the carpal tunnel, the median nerve divides into:
  • Lateral digital branch
    • Enters the thenar eminence and supplies abductor pollicis brevis, flexor pollicis brevis, opponens pollicis, and first lumbrical muscles
  • Medial digital branch
    • Divides into variable number of digital nerves; supplies second lumbrical muscle
• Carpal tunnel pressures (mean):
  • Wrist in neutral position
    • 25 mm Hg, healthy
    • 32 mm Hg, CTS
  • 90 degrees of wrist flexion
    • 31 mm Hg, healthy
    • 99 mm Hg, CTS
  • 90 degrees of wrist extension
    • 30 mm Hg, healthy
    • 110 mm Hg, CTS

• Post-Procedure: Standard Open Approach
• Post-Procedure: Endoscopic Release Through Single Incision (Agee Single-Portal Technique)
• Post-Procedure: Endoscopic Release Through Two Incisions (Chow Two-Portal Extrabursal Technique)

Post-Procedure: Standard Open Approach

POST-PROCEDURE CARE

• Post-procedure care is largely similar whether an open, single-port arthroscopy or double-port arthroscopy technique is used.
• Postoperative splinting remains somewhat controversial.
  • A compression dressing and volar splint can be applied.
• Active use of hand should occur as soon as possible after surgery.
  • Progression of light activities of daily living is allowed at about 2 to 3 weeks.
  • More strenuous activities are added in the next 4 to 6 weeks.
• The sutures are removed after 10 to 14 days.
• The splint is continued for comfort as needed for 14 to 21 days.

COMPLICATIONS

• For open release, complications and failures are estimated to be between 3% and 19%:
  • Incomplete release of the transverse carpal ligament
  • Reformation of the flexor retinaculum
  • Scarring in the carpal tunnel
  • Median or palmar cutaneous neuroma
  • Palmar cutaneous nerve entrapment
  • Recurrent granulomatous or inflammatory tenosynovitis
  • Hypertrophic scar in the skin
• The open approach may cause prolonged scar tenderness and weakness of grip within the first 6 months postoperatively.
• The complications relating to endoscopic procedures are evolving as the procedures are modified from their original descriptions.
• Incomplete release is a common complication
  • Major injuries, such as complete or near-complete transection, have occurred endoscopically and include injury to the median and ulnar nerves, flexor tendons, and superficial palmar arch.

ANALYSIS OF RESULTS

• Nonoperative management including corticosteroid injections and splinting has long-term benefit in 10% of patients.
• Maximum benefit of operative management is at 6 months.
• There are no significant differences between endoscopic and open carpal tunnel release.

OUTCOMES AND EVIDENCE

• Nonoperative management
  • Graham et al: corticosteroid injection and splinting
    • Long-term benefit in 10% of patients
  • Weiss, Sachar, and Gendreau: compared the efficacy of steroid injection with splinting
    • Response to injection treatment was faster in men and in patients over 40 years of age.
  • Kaplan, Glickel, and Eaton: success of nonoperative treatment in a study of 331 patients with carpal tunnel syndrome
    • 5 important factors in determining the success of nonoperative treatment:
      • Age over 50 years
      • Duration longer than 10 months
      • Constant paresthesia
      • Stenosing flexor tenosynovitis
      • A positive Phalen test result in less than 30 seconds.
    • 0 factors present: 66% cured by medical treatment
    • 1 factor present: 60% cured by medical treatment
    • 2 factors present: 16% cured by medical treatment
    • 3 factors: 7% cured by medical treatment
    • 4-5 factors: 0% cured by medical treatment
• Operative
  • Guyette and Wilgis: prospective study
    • Maximum improvement in the first 6 months after carpal tunnel release
    • After 6 months, there was no significant improvement in the Tinel and Phalen tests, pinch strength, motor latency, symptom severity, or functional scoring.
      • Although thenar atrophy may disappear, it resolves slowly, if at all.
  • Leit, Weiser, and Tomaino
    • 70 years old with advanced disease
      • May not achieve complete relief of all symptoms
• Endoscopy
  • Ferdinand and MacLean, and Macdermid et al: prospective studies comparing open and endoscopic carpal tunnel release
    • No significant differences in function
  • Macdermid et al
    • Immediate postoperative advantages of the endoscopic technique in grip strength and pain relief disappeared after 12 weeks.

Post-Procedure: Endoscopic Release Through Single Incision (Agee Single-Portal Technique)

POST-PROCEDURE CARE

• Post-procedure care is largely similar whether an open, single-port arthroscopy or double-port arthroscopy technique is used.
• Postoperative splinting remains somewhat controversial.
  • A compression dressing and volar splint can be applied.
• Active use of hand should occur as soon as possible after surgery.
  • Progression of light activities of daily living is allowed at about 2 to 3 weeks.
  • More strenuous activities are added in the next 4 to 6 weeks.
• The sutures are removed after 10 to 14 days.
• The splint is continued for comfort as needed for 14 to 21 days.

COMPLICATIONS

• For open release, complications and failures are estimated to be between 3% and 19%:
  • Incomplete release of the transverse carpal ligament
  • Reformation of the flexor retinaculum
  • Scarring in the carpal tunnel
  • Median or palmar cutaneous neuroma
  • Palmar cutaneous nerve entrapment
  • Recurrent granulomatous or inflammatory tenosynovitis
  • Hypertrophic scar in the skin
• The open approach may cause prolonged scar tenderness and weakness of grip within the first 6 months postoperatively.
• The complications relating to endoscopic procedures are evolving as the procedures are modified from their original descriptions.
• Incomplete release is a common complication
  • Major injuries, such as complete or near-complete transection, have occurred endoscopically and include injury to the median and ulnar nerves, flexor tendons, and superficial palmar arch.

ANALYSIS OF RESULTS

• Nonoperative management including corticosteroid injections and splinting has long-term benefit in 10% of patients.
• Maximum benefit of operative management is at 6 months.
• There are no significant differences between endoscopic and open carpal tunnel release.

OUTCOMES AND EVIDENCE

• Nonoperative management
  • Graham et al: corticosteroid injection and splinting
    • Long-term benefit in 10% of patients
  • Weiss, Sachar, and Gendreau: compared the efficacy of steroid injection with splinting
    • Response to injection treatment was faster in men and in patients over 40 years of age.
  • Kaplan, Glickel, and Eaton: success of nonoperative treatment in a study of 331 patients with carpal tunnel syndrome
    • 5 important factors in determining the success of nonoperative treatment:
      • Age over 50 years
      • Duration longer than 10 months
      • Constant paresthesia
      • Stenosing flexor tenosynovitis
      • A positive Phalen test result in less than 30 seconds.
    • 0 factors present: 66% cured by medical treatment
    • 1 factor present: 60% cured by medical treatment
    • 2 factors present: 16% cured by medical treatment
    • 3 factors: 7% cured by medical treatment
    • 4-5 factors: 0% cured by medical treatment
• Operative
  • Guyette and Wilgis: prospective study
    • Maximum improvement in the first 6 months after carpal tunnel release
    • After 6 months, there was no significant improvement in the Tinel and Phalen tests, pinch strength, motor latency, symptom severity, or functional scoring.
      • Although thenar atrophy may disappear, it resolves slowly, if at all.
  • Leit, Weiser, and Tomaino
    • 70 years old with advanced disease
      • May not achieve complete relief of all symptoms
• Endoscopy
  • Ferdinand and MacLean, and Macdermid et al: prospective studies comparing open and endoscopic carpal tunnel release
    • No significant differences in function
  • Macdermid et al
    • Immediate postoperative advantages of the endoscopic technique in grip strength and pain relief disappeared after 12 weeks.

Post-Procedure: Endoscopic Release Through Two Incisions (Chow Two-Portal Extrabursal Technique)

POST-PROCEDURE CARE

• Post-procedure care is largely similar whether an open, single-port arthroscopy or double-port arthroscopy technique is used.
• Postoperative splinting remains somewhat controversial.
  • A compression dressing and volar splint can be applied.
• Active use of hand should occur as soon as possible after surgery.
  • Progression of light activities of daily living is allowed at about 2 to 3 weeks.
  • More strenuous activities are added in the next 4 to 6 weeks.
• The sutures are removed after 10 to 14 days.
• The splint is continued for comfort as needed for 14 to 21 days.

COMPLICATIONS

• For open release, complications and failures are estimated to be between 3% and 19%:
  • Incomplete release of the transverse carpal ligament
  • Reformation of the flexor retinaculum
  • Scarring in the carpal tunnel
  • Median or palmar cutaneous neuroma
  • Palmar cutaneous nerve entrapment
  • Recurrent granulomatous or inflammatory tenosynovitis
  • Hypertrophic scar in the skin
• The open approach may cause prolonged scar tenderness and weakness of grip within the first 6 months postoperatively.
• The complications relating to endoscopic procedures are evolving as the procedures are modified from their original descriptions.
• Incomplete release is a common complication
  • Major injuries, such as complete or near-complete transection, have occurred endoscopically and include injury to the median and ulnar nerves, flexor tendons, and superficial palmar arch.

ANALYSIS OF RESULTS

• Nonoperative management including corticosteroid injections and splinting has long-term benefit in 10% of patients.
• Maximum benefit of operative management is at 6 months.
• There are no significant differences between endoscopic and open carpal tunnel release.

OUTCOMES AND EVIDENCE

• Nonoperative management
  • Graham et al: corticosteroid injection and splinting
    • Long-term benefit in 10% of patients
  • Weiss, Sachar, and Gendreau: compared the efficacy of steroid injection with splinting
    • Response to injection treatment was faster in men and in patients over 40 years of age.
  • Kaplan, Glickel, and Eaton: success of nonoperative treatment in a study of 331 patients with carpal tunnel syndrome
    • 5 important factors in determining the success of nonoperative treatment:
      • Age over 50 years
      • Duration longer than 10 months
      • Constant paresthesia
      • Stenosing flexor tenosynovitis
      • A positive Phalen test result in less than 30 seconds.
    • 0 factors present: 66% cured by medical treatment
    • 1 factor present: 60% cured by medical treatment
    • 2 factors present: 16% cured by medical treatment
    • 3 factors: 7% cured by medical treatment
    • 4-5 factors: 0% cured by medical treatment
• Operative
  • Guyette and Wilgis: prospective study
    • Maximum improvement in the first 6 months after carpal tunnel release
    • After 6 months, there was no significant improvement in the Tinel and Phalen tests, pinch strength, motor latency, symptom severity, or functional scoring.
      • Although thenar atrophy may disappear, it resolves slowly, if at all.
  • Leit, Weiser, and Tomaino
    • 70 years old with advanced disease
      • May not achieve complete relief of all symptoms
• Endoscopy
  • Ferdinand and MacLean, and Macdermid et al: prospective studies comparing open and endoscopic carpal tunnel release
    • No significant differences in function
  • Macdermid et al
    • Immediate postoperative advantages of the endoscopic technique in grip strength and pain relief disappeared after 12 weeks.