Finger fractures and dislocations are commonly seen in the primary care setting, and finger fractures are the most common type of fracture in sports.¹ Patients often present with a deformity, swelling, and bruising with loss of function. Radiography can identify fractures and distinguish uncomplicated injuries that can be managed by a primary care physician. Appropriate management strategies help the patient return to normal function while minimizing complications.

Fractures

To evaluate suspected finger fractures, anteroposterior, lateral, and oblique radiography should be performed.² Primary care physicians can manage most nondisplaced, well-approximated fractures with simple immobilization. Diagnosis and management recommendations for finger fractures are outlined in Table 1. The recommendations for fractures in this article apply to adolescent and adult patients without evidence of open growth plates on plain radiography and do not apply to children.

DISTAL PHALANX

Distal phalanx fractures are typically the result of a crush or axial load injury (i.e., direct force to the end of the finger). Physical examination usually shows swelling, bruising, or a subungual hematoma. Radiography demonstrates the location and degree of the bony injury. 

It is important to assess the patient's ability to fully flex and extend the distal interphalangeal (DIP) joint. Distal sensation should also be evaluated. The inability to flex or extend the joint, loss of distal sensation, and complex fractures warrant evaluation by an orthopedic specialist. 

In the absence of these concerns, splinting the DIP joint in full extension for four to six weeks is usually sufficient.³ Large (greater than 50% of the nail surface) or painful subungual hematomas benefit from drainage through the nail using a sterile bore or a heat or cautery instrument.⁴

DORSAL AVULSION FRACTURE OR EXTENSOR TENDON RUPTURE (MALLET FINGER)

Mallet finger occurs when the DIP joint is forced to flex against resistance (Figure 1⁵). This can cause avulsion of the extensor tendon from its attachment at the dorsal base of the distal phalanx, with or without avulsion of a bone fragment at the end of the tendon.⁶ Absence of a bony avulsion indicates a pure tendon rupture.

Patients with mallet finger have swelling, bruising, pain, and the inability to actively extend the DIP joint, which is typically slightly flexed due to the unopposed flexor tendon. Radiography is needed to evaluate intra-articular involvement because injuries involving greater than one-third of the joint surface require referral for possible surgical repair. Injuries in which the joint cannot be passively extended require referral to an orthopedic specialist.⁷ 

In the absence of indications for referral, mallet finger (with or without an avulsion fracture) can be effectively treated with strict immobilization.⁸ The DIP joint should be splinted in full extension to slight hyperextension for eight weeks.^9,10 A dorsally padded aluminum splint, a volar splint, or a thermoplastic stack splint can be used.¹¹ It is important to adhere to the immobilization period because premature flexion of the DIP joint can disrupt the healing process and require an additional eight weeks of hyperextension from the time of premature flexion.

FLEXOR DIGITORUM PROFUNDUS AVULSION FRACTURE

A flexor digitorum profundus avulsion fracture (jersey finger) is typically caused by forceful extension of the DIP joint when in a flexed position (Figure 2⁵). This forceful extension leads to an avulsion fracture at the site where the flexor digitorum profundus tendon attaches to the volar base of the distal phalanx.⁵ Although flexor digitorum profundus avulsion fractures can occur in any finger, they most commonly affect the ring finger.

The examination usually reveals swelling, volar-sided pain, and a slightly extended finger when at rest, and patients are usually unable to actively flex the DIP joint.¹² These findings alone (regardless of radiography results) require expedited referral to an orthopedic specialist because flexor digitorum profundus avulsion fractures can benefit from surgery within seven to 10 days. 

Radiography is needed to identify intraarticular involvement. A visible bone fragment also warrants referral because some injuries require surgical fixation.¹³ When referring a patient to a specialist, the affected finger may be splinted with the proximal interphalangeal (PIP) and DIP joints in slight flexion.

MIDDLE OR PROXIMAL PHALANX

Middle or proximal phalanx fractures are typically due to a direct blow or an axial load injury. Examination reveals swelling, bruising, tenderness, and occasionally deformity. Clinicians should evaluate for malrotation by having the patient attempt to make a fist. If a phalanx is malrotated, there will be an overlap deformity when flexing the affected digit into a fist (Figure 3¹⁴). Comparison to the uninjured hand can be helpful. If malrotation is present, referral for surgery is indicated.^14–16

Radiography is needed to detect oblique, spiral, displaced, or rotational fractures that may not have been detected on examination and to determine if a fracture is intra- or extra-articular. Intra-articular, oblique, spiral, and rotational fractures typically require referral for surgery.¹⁴ 

Minimally angulated (less than 10 degrees) extra-articular fractures without indications for referral can be managed in the primary care setting. Stabilization is achieved by buddy taping the fractured phalanx to the adjacent finger for three to four weeks, based on the return of comfortable function¹⁵ (Figure 4⁵). Taping between the PIP and metacarpophalangeal (MCP) joints serves as a dynamic splint that allows free movement and prevents tendinous complications.

More severely angulated and displaced fractures can also be managed in primary care settings if the clinician is comfortable performing the reduction procedure. Reduction involves applying traction on the distal portion of the phalanx and guiding the bone back into place. Reduction commonly requires oral analgesics or a digital or hematoma block. Postreduction radiography should be performed to confirm successful realignment. Reduced fractures have a higher risk of becoming displaced or angulated during the healing process and therefore require immobilization with an ulnar or radial gutter splint, depending on the affected digit (Figure 5¹⁷).

Dislocations

Finger joint dislocations are usually hyperextension injuries caused by an object striking the finger. Examination usually reveals significant tenderness, especially around the volar surface of the joint, edema, and ecchymoses. Anteroposterior, lateral, and oblique radiography is performed for the initial assessment of the injury and postreduction.^2,14 Dislocations are described by the positioning of the distal phalanx relative to the proximal phalanx. Diagnosis and management recommendations for dislocations are outlined in Table 2.

PIP JOINT: DORSAL

Finger dislocations usually involve the PIP joint, and dorsal (hyperextension) dislocations are most common. A specific injury in a dorsal dislocation is damage to the volar plate, a thick ligamentous structure on the palmar or volar surface of the PIP joint. Hyperextension can tear the volar plate, or tension applied to the volar plate can cause fracturing of the middle phalanx's proximal volar lip.¹⁴ If untreated, the volar plate shortens and thickens, resulting in a flexion deformity of the PIP joint.¹⁸ 

Reduction of a dorsal PIP joint dislocation involves firmly grasping the middle and proximal phalanges while applying gentle traction across the joint (Figure 6¹⁹). The PIP joint is hyperextended to reapproximate the articular surface and then slowly flexed to the anatomic position. The volar plate should be palpated to ensure no tenderness is present. If a volar plate injury is suspected, splinting is recommended for four to six weeks, then advancing motion as tolerated.

After successful reduction and radiographic confirmation, the PIP joint should be buddy taped to an adjacent finger. Dorsal dislocations should be treated using an extension-block splint, with the finger slightly flexed at 20 to 30 degrees for two to three weeks (Figure 7¹⁷), then progressive flexion as tolerated. Protected early motion (within one week as allowed by pain and swelling) is encouraged after dorsal dislocations of the PIP joint.²

PIP JOINT: VOLAR

The volar plate is usually preserved in volar dislocations, but there is often a disruption in a portion of the dorsally located extensor tendon (referred to as the central slip).¹⁶ Injury to the central slip weakens the ability of the PIP joint to extend, but sparing of the lateral band extensor tendons allows for the extension of the DIP joint. If untreated, a central slip injury can result in a boutonniere deformity (Figure 8).⁵

Volar dislocations are reduced in the same way as dorsal dislocations.²⁰ Once reduction is performed, evaluation for a central slip disruption should be done by placing the PIP joint at 90 degrees on the edge of a table and asking the patient to extend the joint against resistance ²¹ (Figure 9). A positive result includes successful extension of the DIP joint but the inability to extend the PIP joint. 

Volar dislocations with suspected central slip disruption should be splinted in full extension for at least four to six weeks. As soon as tolerated, active flexion and extension range-of-motion exercises of the DIP and MCP joints are encouraged while the PIP joint is splinted.²⁰ Patients should be warned that even with optimal treatment, edema may be permanent, and pain can persist for more than one year.

DIP JOINT

DIP joint dislocations are less common and are usually due to a crush injury in which an object (e.g., baseball) hits the finger, causing the DIP joint to hyperextend or hyperflex. Radiography is needed to determine whether a concomitant fracture is present. 

Reduction of a dorsal DIP joint dislocation involves applying gentle traction, hyperextending the DIP joint, and then returning the joint to the correct anatomic position. If there is a wound (usually present over the volar surface), it is considered an open dislocation and should be treated surgically to avoid infection. Additional surgical indications include the inability to reduce the injury, prolonged dislocation, or persistent instability despite relocation.¹⁵ 

If there is no fracture, the DIP joint should be splinted in full extension (for volar dislocations) or 15 to 30 degrees of flexion (for dorsal dislocations) for two to three weeks, depending on patient comfort, followed by an active range-of-motion exercise program.

MCP JOINT

This section discusses MCP joint dislocations of the digits, excluding the thumb. MCP dislocations are usually due to a direct blow, causing hyperextension injury. The MCP joint can be dislocated in the dorsal (most common), volar, or lateral plane.² Similar to the PIP joint, dorsal MCP joint dislocations can cause volar plate injuries. MCP joint dislocations are further divided into simple vs. complex dislocations, which can be determined using radiography. 

Simple dislocations maintain some contact between the two articular surfaces of the MCP joint. However, complex dislocations show no continuity between the joint surfaces and can involve sesamoids or relocation of other soft tissues within the joint, making closed reduction difficult. 

Simple dorsal dislocations are managed immediately with reduction and a dorsal extension-block splint set at 30 to 60 degrees of flexion for seven to 10 days, then transitioned to buddy taping and early range of motion.²² Patients with dorsal dislocations that cannot be easily reduced or have characteristics of a complex injury on plain radiography should be referred immediately to an orthopedic specialist. Volar dislocations of the MCP joint are rare and require referral to an orthopedic specialist. 

Simple lateral dislocations can be managed with a dorsal extension-block splint set at 30 to 60 degrees of flexion for three weeks, followed by buddy taping for another two to three weeks. Lateral dislocations that occurred more than two weeks previously and involve greater than 20% of the joint surface or are displaced by greater than 2 mm warrant referral to an orthopedic specialist. Lateral dislocations may also result in injury to or instability of the radial collateral ligament because they usually tilt toward the ulna and should prompt surgical evaluation. 

This article updates a previous article on this topic by Borchers and Best.¹⁹

Data Sources: A PubMed search was completed in Clinical Queries using the key terms finger, fracture, and dislocation. The search included meta-analyses, randomized controlled trials, clinical trials, and reviews. Also searched were the Agency for Health-care Research and Quality evidence reports, Clinical Evidence, the Cochrane database, Essential Evidence Plus, the Institute for Clinical Systems Improvement, and DynaMed. Search dates: April 14, 2021, and March 8, 2022.