AUTHOR AND EDITOR INFORMATION

Section 1 of 12  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

INTRODUCTION

Section 2 of 12  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

Carpal tunnel syndrome (CTS) is the most commonly diagnosed and treated entrapment neuropathy. The syndrome is characterized by pain, paresthesia, and weakness in the median nerve distribution of the hand. Surgical and nonsurgical treatments exist that can produce excellent outcomes for patients.

For excellent patient education resources, visit eMedicine's Hand, Wrist, Elbow, and Shoulder Center and Arthritis Center. Also, see eMedicine's patient education article Carpal Tunnel Syndrome.

Related eMedicine topics:
Carpal Tunnel Syndrome [Emergency Medicine]
Carpal Tunnel Syndrome [Physical Medicine and Rehabilitation]
Carpal Tunnel Syndrome [Radiology]

Related Medscape topics:
Resource Center Joint Disorders
Resource Center Pain Management: Pharmacologic Approaches
Resource Center Rheumatoid Arthritis
Specialty Site Orthopaedics

History of the Procedure

In 1854, Sir James Paget first reported median nerve compression at the wrist following a distal radius fracture.¹ In 1880, James Putnam presented the first series of patients with pain and paresthesia in the median nerve distribution of the hand. In 1913, Pierre Marie and Charles Foix described the pathology of median nerve compression underneath the transverse carpal ligament (TCL).² In 1933, Sir James Learmonth reported the first TCL release to treat median nerve compression at the wrist.³ Since these early reports, much work has described the signs and symptoms of CTS, as well as its treatments.

Frequency

Carpal tunnel syndrome (CTS) is common in the general population.⁴ It has previously been reported with acute onset following trauma to the wrist; it has also been detailed as a gradual progression of symptoms typically occurring in women who are in the late middle-aged years of life. A new population at risk has been reported to be industrial workers whose hands and wrists are subjected to repetitive motion and trauma.^{5, 6}

Controversy exists regarding the clinical and electrophysiologic findings necessary to diagnose CTS. Despite this controversy, several surveys have been conducted to determine the prevalence of CTS in the general population. In the Netherlands, the prevalence of undetected CTS was 5.8% in women and 0.6% in men.⁴ In Sweden, the overall prevalence of CTS in the population was 2.7%. These prevalence rates were based on clinical and electrophysiologic criteria and probably represent minimum prevalence rate estimates.

Etiology

The etiology of carpal tunnel syndrome (CTS) is multifactorial, with local and systemic factors contributing to varying degrees. Symptoms of CTS are a result of median nerve compression at the wrist, with ischemia and impaired axonal transport of the median nerve across the wrist.⁷ Compression results from elevated pressures within the carpal canal.

Elevated pressures can develop within the carpal canal even though the canal is not a separate, closed compartment within the upper extremity. Direct pressure or a space-occupying lesion within the carpal canal can increase pressure on the median nerve and produce CTS. Fracture callus, osteophytes, anomalous muscle bodies, tumors, hypertrophic synovium, and infection, as well as gout and other inflammatory conditions, can produce increased pressure within the carpal canal. Extremes of wrist flexion and extension also elevate pressure within the carpal canal.

Compression of a nerve affects intraneural blood flow.^{8, 9, 10} Pressures as low as 20-30 mm Hg retard venular blood flow in a nerve. Axonal transport is impaired at 30 mm Hg. Neurophysiologic changes manifested as sensory and motor dysfunction are present at 40 mm Hg. Further increases in pressure produce increasing sensory and motor block. At 60-80 mm Hg, complete cessation of intraneural blood flow is observed. In one study, the carpal canal pressures in patients with CTS averaged 32 mm Hg, compared with only about 2 mm Hg in control subjects.⁸

The double crush syndrome, in which there is pressure on the median nerve at a second site (remote from the wrist), can further lower the median nerve's pressure threshold for producing symptoms of CTS. If a nerve is compressed at multiple sites, traction within the nerve with joint motion may be produced. In addition to pressure, traction or stretch has been demonstrated to produce alterations in intraneural circulation. Elongation of only 8% can impair venular flow, and all intraneural microcirculation can cease at 15% nerve elongation.

Many systemic conditions are strongly associated with CTS. These conditions may directly or indirectly affect microcirculation, pressure thresholds for nerve conduction, nerve cell body synthesis, and axon transport or interstitial fluid pressures. Perturbations in the endocrine system, as observed in individuals with diabetes and hypothyroidism and in women who are pregnant, are linked to CTS. Conditions affecting metabolism (eg, alcoholism, renal failure with hemodialysis, mucopolysaccharidoses) also are associated with CTS.

The international debate regarding the relationship between CTS and the performance of repetitive motion and work is ongoing.^{5, 6} The Occupational Safety and Health Administration (OSHA) has adopted rules and regulations regarding cumulative trauma disorders. Occupational risk factors—repetitive tasks, force, posture, and vibration—have been cited. However, the American Society for Surgery of the Hand has issued a statement that the current literature does not support a causal relationship between specific work activities and the development of diseases such as CTS.

Psychosocial and socioeconomic issues are increasingly being studied. In a study of risk factors for CTS in women, the greatest risk factor was found to be a previous history of another musculoskeletal complaint.¹¹ Perceptions of health and tolerance to pain also may influence the development of CTS.

Pathophysiology

The pathophysiology of carpal tunnel syndrome (CTS) is typically demyelination. In more severe cases, secondary axonal loss may be present. The most consistent findings in biopsy specimens of tenosynovium from patients undergoing surgery for idiopathic CTS have been vascular sclerosis and edema.¹² Localized amyloid deposition in the tenosynovium also has been reported in persons with idiopathic CTS. Inflammation, specifically tenosynovitis, is not part of the pathophysiologic process in chronic, idiopathic CTS.

Clinical

Acute carpal tunnel syndrome (CTS) can develop following a major trauma to the upper extremity (typically a distal radius fracture), a carpal dislocation, or a crush injury. Swelling, pain, and paresthesia in the median nerve distribution of the hand (palmar and radial) are observed.

In the more common idiopathic or chronic CTS, symptoms are more gradual in onset.¹³ Pain and paresthesia in the median nerve distribution of the hand are common. Symptoms are often worse at night and can wake a patient from sleep. As the condition worsens, daytime paresthesia becomes common and is often aggravated by daily activities, such as driving, combing the hair, and holding a book or phone. Weakness can be present. With long-standing or severe cases of CTS, thenar atrophy is frequently observed.

Because of the motor and sensory disturbances, manual dexterity is diminished, and difficulty with such daily activities as buttoning clothes and holding small objects is often encountered. Pain and paresthesia can also occur proximally in the forearm, elbow, shoulder, and neck in up to one third of patients. Pain and paresthesia in the hand are not always isolated to median nerve distribution but can involve the ulnar aspect or the entire hand.

INDICATIONS

Section 3 of 12  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

Acute carpal tunnel syndrome (CTS) can be thought of as a compartment syndrome of the carpal canal, and decompression should be performed as soon as possible, assuming that reduction of associated fractures or dislocations or removal of tight splints does not relieve the symptoms. Other medical and surgical factors may impact the opportunity to operate emergently, but relieving pressure on the median is a priority in order to reduce the risk of permanent nerve injury. Acute CTS can be diagnosed through history and physical examination alone. Electrophysiologic studies are not required. Sometimes, carpal canal pressure measurements are made to help support the diagnosis of acute CTS, with pressures greater than 30 mm Hg being consistent with the diagnosis.

Chronic CTS presents over time and is treated in an operative and nonoperative fashion. Patients with milder symptoms and shorter nerve conduction delays on electrodiagnostic studies respond most favorably to nonoperative treatments. Patients with more severe symptoms—duration longer than 1 year, weakness, atrophy, radial-sided hand numbness, 2-point discrimination greater than 6 mm, and longer nerve conduction delays—often do not benefit from nonoperative care. Failure or findings that are predictive of nonoperative treatment failure are indications for surgical treatment of CTS.

RELEVANT ANATOMY

Section 4 of 12  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

The carpal canal is a fibro-osseous tunnel at the wrist through which 9 flexor tendons and the median nerve pass.¹⁴ The carpal bones define the dorsal aspect of the carpal canal and are shaped in a concave arch. The palmar aspect of the carpal canal is defined by the TCL, which bridges the 2 sides of the carpal arch. Intrinsic and extrinsic ligaments of the wrist and hand further stabilize the carpal bones. The carpal canal is narrowest at the level of the hook of the hamate, where the canal averages 20 mm in width.

The TCL attaches to the scaphoid tuberosity and trapezial crest on the radial side of the wrist, as well as to the pisiform and hook of the hamate on the ulnar side of the wrist (see Image 1). The TCL is 1.5 mm thick and 21.7 mm in length on average. Proximally, the TCL is a continuation of the antebrachial fascia in the forearm, and distally, the TCL attaches to the fibers of the midpalmar fascia. The TCL is under tension and helps to maintain the carpal arch. It serves as a retinacular pulley for the flexor tendons. Cutting the TCL increases the volume of the carpal canal. Cutting the TCL has also been postulated to alter the kinematics of the carpus, risk bowstringing of the flexor tendons, and decrease grip strength.

A combination of the lateral (C6-7) and medial (C8-T1) cords of the brachial plexus forms the median nerve. At the wrist and into the palm, the median nerve divides into terminal motor and sensory branches, with some anatomic variability. The variability is caused in part by the branching point of the recurrent motor branch. An extraligamentous pattern, with a branching point distal to the TCL, is the most common. The recurrent motor branch can also divide from the median nerve underneath the TCL in a subligamentous fashion; it can then either wrap around the distal end of the TCL or pass directly through the TCL to innervate the thenar muscles. Other less common patterns, such as a branch point proximal to the TCL, exist as well. These variations can have major surgical implications.

The ulnar nerve is the other major motor and sensory nerve of the hand. The ulnar nerve does not pass through the carpal canal but instead goes through the Guyon canal, which is located adjacent to the carpal canal, at the wrist. Division of the TCL will change the morphology of the Guyon canal from triangular to ovoid.

See also the following related eMedicine topic:
Carpal Bone Injuries

CONTRAINDICATIONS

Section 5 of 12  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

No specific contraindications exist for surgical treatment of carpal tunnel syndrome (CTS). Medical conditions should be stabilized prior to surgery. Pregnancy should be allowed to proceed to term, because CTS often resolves after the pregnancy. Unrealistic expectations can influence surgical outcomes, and risk factors for poor outcomes should be sought pre-operatively. Individuals with severe CTS should be cautioned that their numbness may persist, at least to some degree, despite a complete surgical release. Patients receiving worker's compensation have a lower return-to-work rate. A greater preference for improved strength pre-operatively also has been associated with lower satisfaction.¹⁵

WORKUP

Section 6 of 12  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

Imaging Studies

• Radiographs
• • Wrist radiographs should not be routinely performed in patients with carpal tunnel syndrome (CTS) because too little useful information is obtained from these images.¹⁶
  • Only 0.4% of routine wrist radiographs for CTS have been demonstrated to provide therapeutically significant findings.¹⁶
  • Patients with a history of systemic disorders, wrist trauma, arthritis, or abnormal findings (eg, limited motion) on physical examination for CTS are much more likely to have radiographic findings; use in these patients may be indicated.

Other Tests

A thorough physical examination of the neck and upper extremity should be performed. Clinical tests to evaluate for carpal tunnel syndrome (CTS) include sensory evaluations and provocative maneuvers that attempt to elicit signs or symptoms of median nerve compression at the wrist. The list below includes the more commonly used tests in the workup.

• Sensory examinations - Threshold tests (Semmes-Weinstein pressure monofilaments and vibratory sensibility) reflect gradual decreases in nerve function, but the innervation density tests (2-point discrimination) can remain normal until nearly all sensory conduction has ceased.
• • Semmes-Weinstein pressure monofilaments - Monofilaments of increasing diameter are pressed perpendicularly against the palmar aspect of each finger until the monofilament bends to determine the sensory threshold for each finger. Values greater than 2.83 may be indicative of CTS.
  • Vibratory sensibility - A 256-cycle per second tuning fork is struck against an object, causing it to vibrate, and the fork's prong is then placed against the patient's fingertips. The median and ulnar fingers of both hands are tested. The test is considered positive if decreased sensation is perceived.
  • Static and moving 2-point discrimination - This is the minimum separation between 2 points (either static or moving) that can be perceived. Failure to discriminate more than 6 mm (static) or 5 mm (moving) is a positive finding.
• Provocative tests
• • Phalen wrist flexion test - The patient's elbows are placed on a table, with the forearms perpendicular to the table and the wrists flexed. This position is held for 60 seconds. The test is positive if numbness or paresthesia develops in radial-sided digits.
  • Tinel test - The examiner taps along the course of the median nerve on the volar aspect of the wrist. The test is positive if paresthesia is elicited in the median nerve distribution.
  • Carpal compression test - Direct application of pressure of 150 mm Hg or even pressure from both thumbs of the examiner is exerted on the patient's carpal canal and is maintained for 30 seconds. The test is positive if pain, numbness, or paresthesia develops in the radial-sided digits.
• Electrophysiologic diagnostic studies - Nerve conduction¹⁷
• • Median motor and sensory latencies, as well as conduction velocities, are measured across the wrist. A sensory latency of greater than 3.5 milliseconds or a motor latency of greater than 4.5 milliseconds is considered an abnormal finding. Comparison with the contralateral hand, as well as with ulnar motor and sensory latencies and conduction velocities, can provide additional evidence supporting the diagnosis of CTS.
  • Distal compound muscle action potential (CMAP) and sensory nerve action potential (SNAP) amplitudes may be decreased in persons with CTS.
  • Minimum F-wave latencies of the median nerve can be prolonged in individuals with CTS.
• Electrophysiologic diagnostic studies - Electromyography
• • This study must be performed with a clinical differential diagnosis in mind; the abductor pollicis brevis is the key muscle to evaluate.
  • Positive findings in persons with CTS include sharp waves, fibrillation potentials, and increased insertional activity.
• When interpreting electrophysiologic studies, remembering that CTS is a clinical diagnosis is important. CTS is a constellation of signs and symptoms caused by the compression and slowing of the median nerve at the wrist. Electrodiagnostic studies should not be used independently in making a diagnosis.

Diagnostic Procedures

• Direct pressure measurement
• • A catheter is inserted directly into the carpal canal to measure pressure.
  • This test is typically used to evaluate acute carpal tunnel syndrome and can help to differentiate between median nerve contusion and compression.
  • The figure of 30 mm Hg is a guide used to determine if the pressure is critically elevated, but physical examination and patient-specific factors can modify the critical pressure.

TREATMENT

Section 7 of 12  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

Medical Therapy

Steroid injection and wrist splinting have been used effectively in patients with milder symptoms of carpal tunnel syndrome. A study reported complete relief of all symptoms in 76% of hands at 6 weeks after treatment, but more than 12 months after treatment, the proportion of hands experiencing complete relief deteriorated to only 22%.¹⁸ Similar positive results have been reported with steroid injection alone in a double-blind, placebo-controlled trial.¹⁹

Other nonoperative treatments have been proposed, but they have not been studied as rigorously; they include nonsteroidal anti-inflammatory drugs (NSAIDs), vitamins (B complex), workstation redesign, ergonomic tool modification, acupuncture, and yoga.

Surgical Therapy

Open and endoscopic surgical techniques have been described for treatment of carpal tunnel syndrome (CTS). Both operative techniques are effective for the treatment of chronic CTS. Potential benefits of the endoscopic technique, including a more rapid functional recovery, have to be weighed against the technique's increased cost and higher complication rate. The reliability of and good visualization provided by the open technique continue to make it the preferred operation for many hand surgeons. Both techniques are described in the following section. Open release with an extended surgical incision is recommended for acute CTS.

Intraoperative Details

Open carpal tunnel release

General, regional, or local anesthesia can be used for the procedure. Surgery is performed with a tourniquet inflated around the arm to control bleeding in the operative field. Open carpel tunnel release is performed as follows:

• A longitudinal incision in the base of the palm is used (see Image 2). The incision is made in line with the flexed ring finger. The intersection of this longitudinal line with the Kaplan line (a line parallel to the ulnar aspect of the extended thumb) marks the distal extent of the incision. Proximally, the incision ends a few millimeters distal to the distal wrist flexion crease.
• Following the incision, the subcutaneous fat is retracted radially and ulnarly, exposing the superficial palmar fascia. The superficial palmar fascia is divided sharply in line with the skin incision. Retractors are placed deeper to expose the TCL.
• A blunt, curved hemostat clamp or similar instrument can be passed deep to the distal edge of the TCL to help confirm position and to protect the contents of the carpal canal. The TCL is divided sharply along its ulnar aspect. Distally, the superficial palmar arch marks the end of the TCL and must be protected. Proximally, the ligament is transected to the level of the distal wrist crease under direct vision.
• Blunt dissecting scissors are used to spread superficial and deep to the antebrachial fascia. Angled retractors are placed proximally under the skin flap so that the antebrachial fascia can now be divided for 2-3 cm proximally under direct vision, using the blunt scissors partially opened in a pushing fashion.
• If visualization is poor, the skin incision may need to be extended proximally. If the incision needs to extend across the distal wrist crease, it should be angled.
• Tenolysis, neurolysis, synovectomy, or reconstruction of the TCL is not routinely performed.
• Prior to closure, the tourniquet is deflated and hemostasis is obtained with bipolar electrocautery. No deep sutures are used. The skin is closed with 4-0 nylon. A soft, sterile dressing is applied.

Postoperative splinting has been recommended to prevent prolapse of nerve, entrapment of nerve in scar tissue, or tendon bowstringing. However, splinting has not been demonstrated to have any beneficial effect and can increase pain and scar tenderness.

Endoscopic carpal tunnel release

One- and 2-incision (ie, portal) techniques are performed as follows^{20, 21}:

• In both techniques, the first incision is made transversely, just proximal to the wrist flexion crease between the palmaris longus and the flexor carpi ulnaris (see Image 3).
• In the 1-incision technique, the blade assembly and viewing device are inserted into the carpal canal anterograde through the proximal incision. With the wrist in extension, the device is advanced to the distal edge of the TCL. Video images, ballottement, and transillumination can be used to confirm the position. When correctly positioned, the cutting blade is elevated, and the device is withdrawn, cutting the distal half of the ligament. The device is then reinserted to inspect ligament division, and additional passes are then made to complete the division of the remaining proximal portions of the ligament. The skin incision is sutured closed.
• In the 2-incision technique, the second incision is made transversely in the palm on a line bisecting the angle formed by lines drawn along the distal border of the fully abducted thumb and the third webspace (see Image 3). Blunt dissection is performed in the palm to identify the superficial palmar arch, the common digital nerves, and the distal edge of the TCL. Following the axis of the forearm, a blunt, curved instrument is inserted into the carpal canal through the proximal incision to free soft tissues from the undersurface of the TCL.
• A trocar-and-sheath assembly is passed anterograde from the proximal incision to the distal incision through the carpal canal. The fingers and wrist are then extended and secured in a custom holder. The trocar is removed, and the endoscope is inserted into the sheath through the proximal incision.
• The distal half of the ligament is then divided with special upward and reverse cutting knives placed in the distal sheath while being viewed through the endoscope.
• The endoscope then is removed and reinserted into the sheath through the distal incision, and the reverse cutting knife is inserted into the sheath through the proximal incision. By withdrawing the reverse cutting knife, the proximal half of the ligament is released. Skin incisions are sutured closed.

The 1- or 2-incision technique, if visualization is not satisfactory, should be abandoned and the surgery converted to open carpal tunnel release.

COMPLICATIONS

Section 8 of 12  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

Complications are not common following open or endoscopic surgical techniques.²² Major complications with either technique can include nerve laceration, vessel laceration, and tendon laceration.^{23, 24} Laceration of the palmar cutaneous branch of the median nerve with painful neuroma formation is reported to be the most common complication of open carpal tunnel release.

Incomplete release of the TCL is reported to be the most common complication of endoscopic carpal tunnel release.²⁵ Loss of grip strength and tenderness of scars following open carpal tunnel release tend to resolve with time.²⁶

The general consensus among surgeons is that nerve injuries occur more frequently with endoscopic release than they do with open release. Nerve injuries with the endoscopic technique are not necessarily related to the skill and experience of the surgeon but may be associated with the nature of the procedure, the anatomy of the carpal canal, and the device used.

OUTCOME AND PROGNOSIS

Section 9 of 12  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

Lasting relief of pain, numbness, and paresthesia can be expected in more than 90% of patients with carpal tunnel syndrome who are treated with open or endoscopic carpal tunnel release; patient satisfaction is high. The endoscopic technique is associated with a shorter interval before the patient returns to work and with less incisional pain.^{20, 27} The primary reason for a poor result is an error in diagnosis.

FUTURE AND CONTROVERSIES

Section 10 of 12  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

The etiology of CTS and its relationship to the workplace will continue to be better understood in the coming decades. It is already apparent that the etiology of CTS is multifactorial, and although work-induced, repetitive trauma may not be the major cause of CTS, it may contribute in some way.

A realized goal of the less invasive endoscopic technique is to return individuals to work sooner. However, concerns over safety and cost have prevented endoscopic techniques from being widely accepted and used. It is hoped that in the future, safer endoscopic methods and less invasive or nonoperative techniques that provide safe and lasting treatment for CTS will be developed.

MULTIMEDIA

Section 11 of 12  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

Media file 1:  Cross sections of the carpal canal at the levels of the proximal and distal carpal rows are depicted. The transverse carpal ligament bridges the carpal tunnel and is under tension.
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Media file 2:  Surgical incision for an open carpal tunnel release is depicted. The incision can be extended proximally across the wrist flexion crease for a more extended exposure.
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Media type:  Image

Media file 3:  Surgical incisions for an endoscopic (1- and 2-incision) carpal tunnel release are depicted. Precise location of the incisions is critical and depends on individual anatomy.
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Media type:  Image

REFERENCES

Section 12 of 12

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

1. Paget J. Lectures on Surgical Pathology. Philadelphia, Pa: Lindsay and Blakiston; 1854.
2. Marie P, Foix C. Atrophie isolee de l'eminence thenar d'origine nevritique: role du ligament annulaire anterieur du carpe dans la pathogenie de la lesion. Revue Neurology (Paris). 1913;26:647-649.
3. Learmonth JR. The principle of decompression in the treatment of certain diseases of peripheral nerves. Surg Clin North Am. 1933;13:905-13.
4. Atroshi I, Gummesson C, Johnsson R, et al. Prevalence of carpal tunnel syndrome in a general population. JAMA. Jul 14 1999;282(2):153-8. [Medline]. [Full Text].
5. Roquelaure Y, Ha C, Pelier-Cady MC, et al. Work increases the incidence of carpal tunnel syndrome in the general population. Muscle Nerve. Jan 30 2008;[Medline].
6. Violante FS, Armstrong TJ, Fiorentini C, et al. Carpal tunnel syndrome and manual work: a longitudinal study. J Occup Environ Med. Nov 2007;49(11):1189-96. [Medline].
7. Lundborg G, Dahlin LB. The pathophysiology of nerve compression. Hand Clin. May 1992;8(2):215-27. [Medline].
8. Gelberman RH, Hergenroeder PT, Hargens AR, et al. The carpal tunnel syndrome. A study of carpal canal pressures. J Bone Joint Surg Am. Mar 1981;63(3):380-3. [Medline].
9. Gelberman RH, Szabo RM, Williamson RV, et al. Tissue pressure threshold for peripheral nerve viability. Clin Orthop Relat Res. Sep 1983;(178):285-91. [Medline].
10. Rydevik B, Lundborg G, Bagge U. Effects of graded compression on intraneural blood flow. An in vivo study on rabbit tibial nerve. J Hand Surg [Am]. Jan 1981;6(1):3-12. [Medline].
11. Ferry S, Hannaford P, Warskyj M, et al. Carpal tunnel syndrome: a nested case-control study of risk factors in women. Am J Epidemiol. Mar 15 2000;151(6):566-74. [Medline]. [Full Text].
12. Fuchs PC, Nathan PA, Myers LD. Synovial histology in carpal tunnel syndrome. J Hand Surg [Am]. Jul 1991;16(4):753-8. [Medline].
13. Naranjo A, Ojeda S, Mendoza D, et al. What is the diagnostic value of ultrasonography compared to physical evaluation in patients with idiopathic carpal tunnel syndrome?. Clin Exp Rheumatol. Nov-Dec 2007;25(6):853-9. [Medline].
14. Cobb TK, Dalley BK, Posteraro RH, et al. Anatomy of the flexor retinaculum. J Hand Surg [Am]. Jan 1993;18(1):91-9. [Medline].
15. Bessette L, Keller RB, Liang MH, et al. Patients' preferences and their relationship with satisfaction following carpal tunnel release. J Hand Surg [Am]. Jul 1997;22(4):613-20. [Medline].
16. Bindra RR, Evanoff BA, Chough LY, et al. The use of routine wrist radiography in the evaluation of patients with carpal tunnel syndrome. J Hand Surg [Am]. Jan 1997;22(1):115-9. [Medline].
17. Kwon BC, Jung KI, Baek GH. Comparison of sonography and electrodiagnostic testing in the diagnosis of carpal tunnel syndrome. J Hand Surg [Am]. Jan 2008;33(1):65-71. [Medline].
18. Gelberman RH, Aronson D, Weisman MH. Carpal-tunnel syndrome. Results of a prospective trial of steroid injection and splinting. J Bone Joint Surg [Am]. Oct 1980;62(7):1181-4. [Medline].
19. Dammers JW, Veering MM, Vermeulen M. Injection with methylprednisolone proximal to the carpal tunnel: randomised double blind trial. BMJ. Oct 2 1999;319(7214):884-6. [Medline]. [Full Text].
20. Agee JM, McCarroll HR Jr, Tortosa RD, et al. Endoscopic release of the carpal tunnel: a randomized prospective multicenter study. J Hand Surg [Am]. Nov 1992;17(6):987-95. [Medline].
21. Chow JC. Endoscopic carpal tunnel release. Two-portal technique. Hand Clin. Nov 1994;10(4):637-46. [Medline].
22. Proubasta IR, Lluch A, Lamas CG, et al. "Fat pad" and "little finger pulp" signs are good indicators of proper release of carpal tunnel. Neurosurgery. Oct 2007;61(4):810-3; discussion 813-4. [Medline].
23. Palmer AK, Toivonen DA. Complications of endoscopic and open carpal tunnel release. J Hand Surg [Am]. May 1999;24(3):561-5. [Medline].
24. Rowland EB, Kleinert JM. Endoscopic carpal-tunnel release in cadavera. An investigation of the results of twelve surgeons with this training model. J Bone Joint Surg Am. Feb 1994;76(2):266-8. [Medline].
25. Bozentka DJ, Osterman AL. Complications of endoscopic carpal tunnel release. Hand Clin. Feb 1995;11(1):91-5. [Medline].
26. Young VL, Logan SE, Fernando B, et al. Grip strength before and after carpal tunnel decompression. South Med J. Sep 1992;85(9):897-900. [Medline].
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Article Last Updated: Aug 12, 2008