Carpal tunnel syndrome

This article, the next in a series on diagnostic and therapeutic injections, covers the wrist and hand region. The rationale, indications, contraindications, and general approach to this technique are covered in the first article of the series. (1) The wrist and hand are sites of multiple injuries and inflammatory conditions that lend themselves to diagnostic and therapeutic injection. (2,3) In this article, we review the anatomy, pathology, diagnosis, and injection technique of common sites for which this skill is applicable. Specific indications include carpal tunnel syndrome, arthritis of the first carpometacarpal joint, de Quervain's tenosynovitis, wrist ganglion cysts, and digital flexor tenosynovitis (trigger finger). For injection of the hand and wrist, the patient should be supine, with the wrist and hand resting comfortably at the patient's side and the targeted area facing upward.

Carpal Tunnel Syndrome

ANATOMY

The carpal tunnel is formed by the carpal bones dorsally, and the transverse carpal ligament (flexor retinaculum), ventrally. The contents of the tunnel include the median nerve and flexor tendons of the hand. The median nerve sensory and motor distribution includes the palmar aspect of the thumb and the index and middle fingers, and it allows opposition of the tip of the thumb with the tips of the fingers.

INDICATIONS AND DIAGNOSIS

Diagnosis of carpal tunnel syndrome is clinical. Electrodiagnostic studies (nerve conduction and electromyography) may assist in confirming the diagnosis, but they have significant false-positive and negative results. (4) Weakness of thumb abduction is a specific and reliable sign. (5) The major indication for carpal tunnel injection is the syndrome of median nerve compression, which may result from osteoarthritis, rheumatoid arthritis, diabetes mellitus, hypothyroidism, repetitive use injury or other traumatic injuries to the area, and pregnancy. The use of local corticosteroid injection for carpal tunnel syndrome has been shown to provide greater clinical improvement in symptoms one month after injection, compared with placebo. (6,7) Long-term randomized controlled trials have not been performed, particularly comparing surgical or nonsurgical approaches with corticosteroid injection.

TIMING AND OTHER CONSIDERATIONS

Injection of the carpal tunnel is considered a later modality after appropriate nonsurgical therapeutic interventions have been undertaken. These include the use of nonsteroidal anti-inflammatory drugs (NSAIDs), splinting, and avoidance of precipitating activities. (8)

TECHNIQUE

Pharmaceuticals and equipment are described in Table 1. Essential landmarks to palpate before performing this injection include the proximal wrist crease and the palmaris longus tendon when present. The palmaris longus tendon is best identified by having the patient pinch all the fingertips together while the wrist is in a neutral position.

APPROACH AND NEEDLE ENTRY

The injection is performed at a site just ulnar to the palmaris longus tendon and at the proximal wrist crease. For those few patients without a palmaris longus tendon, the needle is inserted just ulnar to the midline of the wrist. The needle is inserted at a 30-degree angle and directed toward the ring finger (Figure 1). If the needle meets obstruction or if the patient experiences paresthesias, the needle should be withdrawn and redirected in a more ulnar fashion. Another injection site is at the volar side of the forearm, 4 cm proximal to the wrist crease between the tendons of the radial flexor muscle and the palmaris longus muscle. (7) In this approach, the angle of insertion is between 10 and 20 degrees depending on the thickness of the wrist. As with any injection, aspirate to ensure that the needle has not been placed in a blood vessel. Inject slowly, but with consistent pressure.

First Carpometacarpal Joint

ANATOMY

The movements of the thumb are dictated by the saddle-shaped articular surface of the base of the first metacarpal, which articulates with the trapezium.

INDICATIONS AND DIAGNOSIS

Pain associated with arthritis or overuse is the most common indication for injection of this joint. (9,10) Diagnosis is determined by limitation of motion and palpation of crepitus and tenderness over the joint. Diagnosis may be confirmed by radiographs.

TIMING AND OTHER CONSIDERATIONS

Injection is usually performed after other more conservative therapies, including use of NSAIDs and a brief period of immobilization, have been tried. (11,12) As with any arthritic joint, relief after injection may only be temporary, and surgical intervention may need to be considered.

TECHNIQUE

Pharmaceuticals and equipment are described in Table 1. Palpate the joint space between the trapezium and the first metacarpal.

APPROACH AND NEEDLE ENTRY

The needle enters just proximal to the first metacarpal on the extensor surface. Care must be taken to avoid the radial artery and the extensor pollicis tendons. To avoid the radial artery, the needle should enter toward the dorsal (ulnar) side of the extensor pollicis brevis tendon. The needle, a 25 gauge, should fall into the joint space (Figure 2). Traction can be applied to the thumb to further open the joint space.

de Quervain's Disease

ANATOMY

This disorder, a stenosing tenosynovitis, involves the abductor pollicis longus and extensor pollicis brevis tendons.

INDICATIONS AND DIAGNOSIS

de Quervain's disease usually occurs with repetitive use of the thumb. (13) Thickening is noted, and tenderness is elicited just distal to the radial styloid process over the site of the involved tendon sheath. The Finkelstein test is performed by having the patient make a fist with the thumb inside while simultaneously ulnar deviating the hand. Pain over the affected area is elicited in de Quervain's disease.

TIMING AND OTHER CONSIDERATIONS

Immobilization and the use of NSAIDs should be tried before injection therapy is performed. (2)

INJECTION TECHNIQUE

Pharmaceuticals and equipment are described in Table 1. With the thumb abducted and extended, palpate the course of the tendons distal to the radial styloid process.

APPROACH AND NEEDLE ENTRY

The needle is placed into the first extensor compartment, directed proximally toward the radial styloid process and sliding in parallel to the abductor and extensor tendons (Figure 3). Do not inject directly into a tendon.

Ganglion Cysts

ANATOMY

Ganglion cysts account for approximately 60 percent of soft tissue, tumor-like swelling affecting the hand and wrist. They usually develop spontaneously in adults 20 to 50 years of age. There is a female-to-male preponderance of 3:1. (14) The dorsal wrist ganglion arises from the scapholunate joint and constitutes about 65 percent of ganglia of the wrist and hand. The volar wrist ganglion arises from the distal aspect of the radius and accounts for about 20 to 25 percent of ganglia. Flexor tendon sheath ganglia make up the remaining 10 to 15 percent. The cystic structures are found near or are attached to tendon sheaths and joint capsules. The cyst is filled with soft, gelatinous, sticky, and mucoid fluid.

INDICATIONS AND DIAGNOSIS

Cysts are self evident, being soft and ballotable, and occur along the dorsal and volar aspects of the wrist. Most ganglia resolve spontaneously and do not require treatment. If the patient has symptoms, including pain or paresthesias, or is disturbed by the appearance, aspiration with or without injection of a corticosteroid is effective (no recurrence of the cyst) in 27 to 67 percent of patients. (15,16)

TIMING AND OTHER CONSIDERATIONS

Aspiration and injection are performed on an elective basis determined by symptoms and patient request.

INJECTION TECHNIQUE

Pharmaceuticals and equipment are described in Table 1. Boundaries of the cyst should be palpated.

APPROACH AND NEEDLE ENTRY

An 18- or 22-gauge needle inserted directly into the cyst should be used to aspirate the cyst after local anesthesia is given. A 20- or 30-mL syringe should be used to provide optimal suction for aspiration. If injecting a corticosteroid after aspiration, a hemostat is used to stabilize the needle while the syringe is changed.

Trigger Finger (Digital Flexor Tenosynovitis)

ANATOMY

All flexor tendons of the hand may develop a tenosynovitis.

INDICATIONS AND DIAGNOSIS

Symptoms develop when a tendon cannot glide within its sheath because of a thickening or nodule that catches at the site of the first annular pulley, preventing smooth extension or flexion of the finger. Patients complain of catching or locking and discomfort with grasping activity of the hand. Trigger finger occurs commonly in patients who have rheumatoid arthritis, diabetes mellitus, and repetitive use injuries. (17)

TIMING AND OTHER CONSIDERATIONS

Compared with previously described disorders, corticosteroid injection is performed earlier in the course of treatment in this disorder. (18,19) Alternatives to injection include splinting and modification of activity. (20)

INJECTION TECHNIQUE

Pharmaceuticals and equipment are described in Table 1. A nodule secondary to the tenosynovitis is usually palpable in the region of the metacarpal head of the affected tendon.

APPROACH AND NEEDLE ENTRY

A 25-gauge, 1-inch, or 1.5-inch needle is inserted over the palmar aspect distal to the metacarpal head at a 30-degree angle and then directed proximally, almost parallel to the skin, toward the nodule (Figure 4).

Follow-Up Care

The patient should remain in the supine position for several minutes after the injection. To ascertain whether the pharmaceuticals have been injected into the appropriate location, move the joint through passive range of motion. For tenosynovitis, stress the finger flexors to ascertain the same. A compression dressing should be applied after aspirating a ganglion cyst. To monitor for any adverse reactions, the patient should remain in the office for 30 minutes after the injection. In general, patients should avoid strenuous activity involving the injected region for 48 hours. Patients should be cautioned that they may experience worsening symptoms during the first 24 to 48 hours related to a possible steroid flare, which can be treated with ice and NSAIDs. A follow-up appointment should be arranged within three weeks.

The authors indicate that they do not have any conflicts of interest. Sources of funding: none reported.

REFERENCES

(1.) Cardone DA, Tallia AF. Joint and soft tissue injection. Am Fam Physician 2002;66:283-8.

(2.) Owen DS Jr. Aspiration and injection of joints and soft tissues. In: Ruddy S, Harris ED, Sledge CB, Kelley WN. Kelley's Textbook of rheumatology, 6th ed. Philadelphia: W.B. Saunders, 2001:583-604.

(3.) Grillet B. Dequeker J. Intra-articular steroid injection. A risk-benefit assessment. Drug Saf 1990;5:205-11.

(4.) Katz JN, Simmons BP. Carpal tunnel syndrome. N Engl J Med 2002;346:1807-12.

(5.) D'Arcy CA, McGee S. The rational clinical examination. Does this patient have carpal tunnel syndrome? JAMA 2000;283:3110-7.

(6.) Marshall S, Tardif G, Ashworth N. Local corticosteroid injection for carpal tunnel syndrome. Cochrane Database Syst Rev 2002;2:CD001554.

(7.) Dammers JW, Veering MM, Vermeulen M. Injection with methylprednisolone proximal to the carpal tunnel: randomised double blind trial. BMJ 1999; 319:884-86.

(8.) Bracker MD. Ralph LP. The numb arm and hand. Am Fam Physician 1995;51:103-16.

(9.) Rettig AC. Wrist problems in the tennis player. Med Sci Sports Exerc 1994;26:1207-12.

(10.) Creamer P. Intra-articular corticosteroid injections in osteoarthritis: do they work and if so, how? Ann Rheum Dis 1997;56:634-6.

(11.) Buckwalter JA, Stanish WD, Rosier RN, Schenck RC Jr, Dennis DA, Coutts RD. The increasing need for nonoperative treatment of patients with osteoarthritis. Clin Orthop 2001;385:36-45.

(12.) Lane NE, Thompson JM. Management of osteoarthritis in the primary-care setting: an evidence-based approach to treatment. Am J Med 1997; 103:25-30S.

(13.) Rettig AC. Wrist and hand overuse syndromes. Clin Sports Med 2001;20:591-611.

(14.) Thornburg LE. Ganglions of the hand and wrist. J Am Acad Orthop Surg 1999;7:231-8.

(15.) Esteban JM, Oertel YC, Mendoza M, Knoll SM. Fine needle aspiration in the treatment of ganglion cysts. South Med J 1986;79:691-3.

(16.) Richman JA, Gelberman RH, Engber WD, Salamon PB, Bean DJ. Ganglions of the wrist and digits: results of treatment by aspiration and cyst wall puncture. J Hand Surg 1987;12:1041-3.

(17.) Sheon RP. Repetitive strain injury. 2. Diagnostic and treatment tips on six common problems. The Goff Group. Postgrad Med 1997;102:72-8,81,85.

(18.) Marks MR, Gunther SF. Efficacy of cortisone injection in treatment of trigger fingers and thumbs. J Hand Surg [Am] 1989;14:722-7.

(19.) Patel MR, Bassini L. Trigger fingers and thumb: when to splint, inject, or operate. J Hand Surg [Am] 1992;17:110-3.

(20.) Quinnell RC. Conservative management of trigger finger. Practitioner 1980;224:187-90.

This article is one in a series of "Office Procedures" articles coordinated by Dennis A. Cardone, D.O., C.A.Q.S.M., associate professor, and Alfred F. Tallia, M.D., M.P.H., associate professor, Department of Family Medicine, UMDNJ--Robert Wood Johnson Medical School, New Brunswick, N.J.

ALFRED F. TALLIA, M.D., M.P.H., is associate professor and vice chair in the Department of Family Medicine at the University of Medicine and Dentistry of New Jersey (UMDNJ)-Robert Wood Johnson Medical School, New Brunswick, N.J. Dr. Tallia is a graduate of the UMDNJ-Robert Wood Johnson Medical School and completed his residency at the Thomas Jefferson University Family Medicine Residency, Philadelphia. He received his public health degree at Rutgers University, New Brunswick, N.J.

DENNIS A. CARDONE, D.O., C.A.Q.S.M., is associate professor and director of sports medicine and the sports medicine fellowship in the Department of Family Medicine at UMDNJ-Robert Wood Johnson Medical School. Dr. Cardone is a graduate of the New York College of Osteopathic Medicine, Old Westbury, N.Y., and completed his residency at the UMDNJ-Robert Wood Johnson Medical School Family Medicine Residency. He completed his sports medicine fellowship at UMDNJ.

Address correspondence to Alfred F. Tallia, M.D., M.P.H., Dept. of Family Medicine, UMDNJ, 1 Robert Wood Johnson Place, MEB288, New Brunswick, NJ 08903 (e-mail: tallia@umdnj.edu). Reprints are not available from the authors.

COPYRIGHT 2003 American Academy of Family Physicians
COPYRIGHT 2003 Gale Group