The hand and wrist complex comprises 27 bones and multiple tendons, muscles, ligaments, and nerves. This complex is integral for performing daily tasks. Hand and wrist injuries represent 25% of all sports-related injuries and can have a major effect on functional activities of daily living.¹ The incidence of these injuries is on the rise as the number of people engaging in sports and active recreational activities is increasing. This article, part I of a two-part series on injections of the hand and wrist, addresses injections for trigger finger, first carpometacarpal joint osteoarthritis, and palmar fibromatosis. Part II addresses injections for carpal tunnel syndrome, ganglion cyst, intersection syndrome, triangular fibrocartilage complex injury, and de Quervain tenosynovitis.²

INITIAL EVALUATION

Point tenderness plays a crucial role in the physical examination when identifying the source of hand pain.^1,3,4 It is critical to assess passive, active, and resisted movements of the hand, followed by evaluating sensation.³

IMAGING

Radiography is the first-line imaging test to assess for fractures and osseous alignment following hand or finger trauma.¹ Radiography can additionally be used to monitor healing of conservatively treated fractures of the hand.¹ Magnetic resonance imaging (MRI) can be used to assess injuries of the ligamentous structures. Further, MRI and computed tomography can be used to identify occult fractures of the carpal, including metacarpal, bones.^5,6 Ultrasonography plays a valuable role in providing point-of-care and dynamic evaluation of tendons, nerves, and muscle and can be used to guide injection and aspiration to treat hand conditions. Although not mandatory, ultrasound guidance helps to ensure injectates, particularly corticosteroids, are introduced safely and accurately.^7–9

COMMON PATHOLOGIES

Initial imaging is usually not needed when the diagnosis is clear. Common hand pathologies suitable for therapeutic injection include stenosing flexor tenosynovitis (trigger finger), carpometacarpal joint osteoarthritis, and palmar fibromatosis (Dupuytren contracture). Injection procedures and techniques for these pathologies are discussed in Table 1.^10–13 Before treating with injections, potential complications—including infection, damage to cartilage, collagen breakdown, skin thinning, and changes in skin color (depending on the substance used for the injection)—should be discussed with the patient.^14–16

TRIGGER FINGER

Trigger finger is a leading cause of hand pain in adults, with a prevalence of about 2% in the general population.¹⁷ Women are more likely to develop this condition, with peak occurrence appearing in their 50s or 60s.¹⁸ Trigger finger is more common in adults with diabetes mellitus, rheumatoid arthritis, or conditions leading to systemic protein deposition such as amyloidosis. In children, it often indicates anatomic variations or inherited conditions.¹⁹

Diagnosis

Trigger finger is caused by inflammation and narrowing of the A1 pulley of the finger flexors, possibly leading to secondary contracture at the proximal interphalangeal joint in severe cases, where fingers may lock in flexion or multiple digits can be affected.¹⁷ At presentation, patients report the finger getting caught in a flexed position that requires manual unlocking.

Physical examination demonstrates locking and catching at the affected metacarpophalangeal joint as the patient flexes and extends the fingers. The physician should feel for irregular motion or clicking at the proximal interphalangeal joint and assess for possible pain or tenderness at the finger's base, a tender nodule, or palmar fascial thickening.²⁰

Radiography is usually not needed; ultrasonography may be considered if the diagnosis is uncertain. Ultrasonography will show flexor tendon thickening or a palmar nodule caused by fascial thickening over the tendon sheath.²¹

Treatment

Trigger finger can be treated with splinting, nonsteroidal anti-inflammatory drugs, and physical therapy, with most cases responding well to conservative care.^22,23 Palpation- or ultrasound-guided local corticosteroid injection can be considered for adults whose symptoms have not resolved after 4 to 6 weeks of conservative therapy; it should be considered as first-line treatment for patients who present with severe locking and incomplete finger flexion or extension^24,25 (Figure 1²⁶). Children are often treated more conservatively with splinting. ²⁷

Evidence for palpation- vs. ultrasound-guided corticosteroid injection is mixed; some studies show no difference,²³ and some studies indicate that ultrasound-guided injections may offer advantages, such as greater delivery accuracy and a more rapid return to work.^28,29 It is acceptable to perform a palpation-guided injection initially, possibly with an ultrasound-guided injection 3 to 6 months later if the original injection has been ineffective.

To perform a palpation-guided injection, a 25-gauge needle, 1 or 1.5 inches in length, is inserted at a 30-degree angle on the palmar side, just beyond the metacarpal head. It is then guided almost parallel to the skin surface, toward the thickened portion of the pulley (felt as a nodule), from a distal position, then the corticosteroid with or without a local numbing agent is injected.

With ultrasound guidance, a needle can be introduced superficially at the level of the inflamed A1 pulley.^22,23 After the needle is inserted, it is advanced distally, and the corticosteroid is injected.^22,23 Figure 1B shows a suggested transducer position and needle placement for ultrasound-guided injection of the condition. Patients with trigger finger that is refractory to conservative care should be referred to a hand surgeon for endoscopic or percutaneous release.³⁰

FIRST CARPOMETACARPAL JOINT OSTEOARTHRITIS

Radiographically confirmed symptomatic hand osteoarthritis is increasing globally and appears to be more prevalent in women and adults older than 70 years.³¹ The carpometacarpal joint, a key articulation point for thumb mobility, is commonly targeted by osteoarthritic degeneration.³² Disease characteristics include pain, swelling, decreased range of motion, and loss of function.³³ Pain at the thumb's base is often worsened by continuous gripping or pinching activities (e.g., sewing), forceful thumb use (e.g., turning a key), and feelings of thumb weakness or a slipping sensation of the joint.³⁴

Diagnosis

Radiography is usually not needed for patients with a clear clinical diagnosis. In cases of diagnostic uncertainty, radiography, MRI, or ultrasonography may be beneficial.³⁵ Imaging may be used to detect and assess the severity of osteoarthritis, including radiography identifying classic features such as osteophytes and joint space narrowing, MRI spotting early-stage osteoarthritis before radiographic signs appear, and ultrasonography revealing osteoarthritis-linked structural changes and pathologies such as synovial inflammation and effusion.^35,36

Treatment

Corticosteroid injection for this condition should be considered if physical or hand therapy and functional bracing have not helped after 4 to 6 weeks, as well as for severe pain and inflammation.³⁷ The injection target should be the basal joint space within the anatomic snuff-box bound by the abductor pollicis longus, extensor pollicis brevis, and extensor pollicis longus tendons. These tendon boundaries can be palpated by fully abducting the thumb (Figure 2A³⁸). During injection, the patient should be seated or supine with the affected hand supine on a stable surface. The ultrasound transducer should be positioned over the anatomic snuff-box and aligned along the long axis of the carpometacarpal joint. The joint space can be identified by the seagull appearance of the carpometacarpal reflection (Figure 2B²⁶). Figure 2C shows a suggested transducer position and needle placement for ultrasound-guided injection of the condition.

To maximize corticosteroid-injection benefit, other treatment modalities such as oral or topical nonsteroidal anti-inflammatory drugs, occupational therapy, and thumb spica splints should continue to be used concomitantly to help improve the patient's symptoms. Corticosteroid injections are effective in relieving pain only about half of the time, and pain recurrence in 1 to 2 years is high. Therefore, direct referral for surgical consultation without first trying an injection, especially for severe osteoarthritis cases, is an acceptable approach.^39,40

PALMAR FIBROMATOSIS (DUPUYTREN CONTRACTURE)

The exact cause of palmar fibromatosis (Dupuytren contracture or nodules) is unclear, but it is influenced by genetics, ethnicity, sex, age, potentially environmental factors, and links to diseases. A higher prevalence occurs in individuals of northern European descent and a significant genetic component (i.e., 68% of male relatives of affected patients may develop the condition).^41,42 Its incidence is associated with repetitive or vibrational occupational exposure and is more common in adults with diabetes.^43,44 Cigarette smoking and alcohol consumption are also contributory factors.⁴⁵

Diagnosis

Although histologic confirmation may be needed, palmar fibromatosis is usually clinically diagnosed. The overlying skin puckers, usually on the distal volar aspect of the palm, where subcutaneous nodules are often found (Figure 3A¹²). Typically, a cord-like expansion of the digital aponeurotic slips of digits 4 and 5 occurs, causing fingers to flex at the metacarpophalangeal and proximal interphalangeal joints, possibly leading to painful flexion contractures.⁴⁶ These may occasionally be accompanied by knuckle pads or concurrent plantar fascia nodules.⁴⁷

Imaging is typically not needed for diagnosis. When the diagnosis is unclear, ultrasonography or MRI can be used and will show nodules and fibrous cords.⁴⁸

Treatment

Treatment of palmar fibromatosis with corticosteroid injection needs further study. When contractures are less than 15 degrees, the nodules can be injected with 60 to 120 mg of triamcinolone acetonide.¹¹ Figure 3B shows a palpation-guided injection, which is performed over the location of maximal thickening.¹² Nodule flattening and softening as part of immediate disease regression has been observed after such injections, occurring in most patients who receive more than three injections over 4 years.¹¹ However, 1 to 3 years after injection, most patients experience disease recurrence.⁴⁹

Collagen degradation, dermal atrophy, and depigmentation are possible adverse effects of corticosteroid injection, although they generally resolve within 6 months.¹¹ Given the associated risks, corticosteroid injection should be attempted only after shared decision-making, particularly in the setting of painful nodules; ultrasound-guided injection is preferred because of improved accuracy.⁴⁸ Figure 3C shows a suggested transducer position and needle placement for ultrasound-guided injection.

Clinical trials have shown that late-stage disease and contractures can be effectively treated using localized collagenase injection, rather than surgical intervention, with improved hand function and decreased contracture rates.⁵⁰ Collagenase injections should be performed by physicians with the requisite training and certification, typically hand surgeons, orthopedists, or rheumatologists. Early symptomatic and asymptomatic nodules may also be treated with collagenase injection; however, treatment safety and rate of recurrence are unknown.

This article updates a previous article on this topic by Tallia and Cardone.²⁶

Data sources: The Medline database (1946 to present) was searched, restricted to English language articles, using the Ovid interface. Search terms included MeSH terms and keywords, including wrist, wrist injuries, wrist fractures, hand, hand bones, hand joints, hand injuries, ulnar nerve, finger, knuckle, injection, injectable, microinjection, and their respective synonyms. Studies were critically reviewed that used patient categories such as race and/or gender but did not define how these categories were assigned, stating their limitations, when applicable, in the text. An Essential Evidence Plus summary was also used. Search dates: January 1, 2019, to February 2, 2023; August 18, 2024.

The Scientific Publications staff at Mayo Clinic provided copyediting, proofreading, administrative, and clerical support.

The authors thank Ryan Milon for modeling for the images in Figure 1B, Figure 2C, and Figure 3C.