Finger Dislocations

DEFINITION

A fracture is a complete or incomplete break in a bone because of a failure of the material.

SYNONYMS

• Phalanx fracture

• P1, P2, P3 fracture

• Phalangeal fractures

• Mallet fracture 

• Boxer fracture 

Finger-Dislocation

ETIOLOGY

• Phalanx fractures are produced through axial compression or spiral or transverse forces on semiflexed or hyperextended digits. Fractures of the proximal phalanx are potentially the most disabling fractures in the hand; direct blows tend to cause transverse or comminuted fractures, whereas twisting injury may cause an oblique or spiral fracture.

• Proximal fragments are usually flexed by intrinsic muscles,whereas distal fragments are extended because of extrinsic compressive forces.

• A frequent complication of both proximal and middle phalanx fractures is the adhesion of the extensor mechanism causing loss of motion in the finger. These fractures can also damage the gliding surface of the flexor tendon sheath as a result of to periosteal injury.

• The periosteum of the bone forms the dorsal wall of the fibroosseous tunnel in which the tendon glides. Adhesion of the tunnel would result in loss of motion of the digit and potentially the entire hand.

• Tendons can also cause increased fracture instability from their opposite directions of pull.For example, a mallet fracture is due to the terminal tendonin avulsion from the DIP joint. A portion of the distal phalanx will move dorsal with the extensor tendon and a portion will move volar with the flexor tendon.

EPIDEMIOLOGY AND 

DEMOGRAPHICS

• Many different groups of people are prone to finger fractures. Children commonly have proximal phalanx base fractures from getting their fingers stuck indoors or drawers.The elderly sustain fractures from falls, 10- to 29-year-olds suffer fractures from sport-related injuries, and 40- to 69-year-olds fracture their fingers most frequently in machinery accidents.

• Middle phalanx fractures account for 8% to 12% of hand fractures.

• Distal phalanx fractures are reported as the most frequent of all hand fractures in adults at a rate of 40% to 50%.

• The proximal phalanx was the most frequently fractured bone among the phalanges in children.

• Salter-Harris fractures are unique to children as they are through the growth plate.The classification system is based on the site and extent of the injury and therefore can determine possible long-term complications.

• Salter-Harris type II is the most common injury.This describes a fracture where a piece of the metaphysis breaks off the epiphysis.The bone may have minimal shortening but will usually not result in functional limitations.

MECHANISM OF INJURY

A finger fracture usually occurs from hitting a hard object with the finger, being hit by a ball, getting the hand slammed in a door,or falling onto the hand.These injuries are common in ball-handling sports.

COMMON SIGNS AND 

SYMPTOMS

• Pain, decreased ROM

• Swelling

• Ecchymosis

• Finger deformity

AGGRAVATING ACTIVITIES

• Any movement that stresses the unstable bone will cause pain

• Gripping

• Pinching

• Lifting objects

• Carrying objects

EASING ACTIVITIES

Ice, elevation, and compression can help limit the edema associated with the fracture.

24-HOUR SYMPTOM PATTERN

If the fracture goes untreated, the pain and swelling will increase while the ROM begins to decrease.

PAST HISTORY FOR THE REGION

• The patient will report a trauma to the hand.It is extremely important to know exactly how the fracture occurred to determine the mechanism of fracture to realize the stability of the fragment.

• Patient may or may not report prior injury to the region.

PHYSICAL EXAMINATION

• Tenderness or pain over the site of fracture

• Ecchymosis

• Loss of ROM

• Rotational deformity is indicated if the fingers do not point toward the proximal portion of the scaphoid with the hand in a fist position

IMPORTANT OBJECTIVE TESTS

Stress radiography: It is important to have stress put through the fracture to determine the true stability of the bone. The periosteum can give the appearance of a stable fracture in a nonstressed image.

DIFFERENTIAL 

DIAGNOSIS

Pathological nontraumatic fracture(enchondroma).

Finger-Dislocation

CONTRIBUTING FACTORS

• High-velocity sports

• Osteoporosis or osteopenia

• Long-term use of the following:

 Prednisone

 Methotrexate

 Corticosteroids

TREATMENT

SURGICAL INDICATORS

• Volarly angulated or condylar fracture

• Spiral oblique fractures are inherently unstable and require internal fixation

• Phalanx fractures involving more than 30% of the joint surface.

Finger-Dislocation

SURGICAL OPTIONS

• Open reduction and internal fixation(ORIF) with screws and/or plates

• Intramedullary nailing

• Pin fixation

• External fixation

SURGICAL OUTCOMES

• Surgery can be extremely effective in terms of stabilizing the fracture.

• Research has reported complications such as plate fixation interfering with the extensor apparatus,faulty technique and malunion.

REHABILITATION

• It is essential for the clinician to know the location, pattern, and stability of hand joints and can begin AROM using a dorsal extension block (DEB) splint. The MCP should be positioned in 30 degrees of flexion,and the IP joints blocked in full extension. This position will limit extension to 30 degrees to maintain the joint congruity.

 The figure-of-eight splint is an example of a DEB that allows functional mobility of the hand while protecting the damaged joint.

 Resultant flexion contractures after PIP joint dorsal dislocation are often mis-diagnosed as a BD.With the extensor tendon intact,the DIP joint will remain flexible. This positioning is termed a pseudoboutonnière deformity.

 Volar PIP joint dislocations usually involve rupture of the central slip and lateral bands.The PIP joint should be treated with immobilization splinting in full extension. Rehabilitation requires up to 6 weeks of PIP joint immobilization splinting or surgical repair of the tendon.

 Central slip extensor tendon ruptures that go undiagnosed with PIP joint volar dislocations become BDs.

• MCP joint dislocation:

 Dorsal MCP joint dislocations should be immobilized with a DEB splint in more than 50 degrees of flexion at the MCP joint. This position maintains the reduction and lengthens the collateral ligaments.

 Full ROM of the IP joints and flexion of the MCP joint should be maintained during the immobilization.The joint should also be included in the DEB splint.

 The buddy tape technique can be used to protect a dislocation for up to 3 months after initial injury.

• Potential complications after a finger dislocation:

 If the dislocation is not reduced properly or reduction is delayed, the joint may have future instability, stiffness or deformity. 

 Fractures are a common complication after overly aggressive attempts to reduce a finger dislocation. 

 Recurrent dislocations are common if the finger was not properly immobilized after the initial reduction.

 Muscle contractures will result with a prolonged immobilization.

 Infections may result from an open fracture not treated with antibiotics and tetanus prophylaxis.

Hand-Rehabilitation

PROGNOSIS

The more quickly the finger dislocation is properly assessed and treatment implemented, the less likely long-term complications will exist.

SIGNS AND SYMPTOMS 

INDICATING REFERRAL 

TO PHYSICIAN

An assessment from a hand surgeon is important for appropriate imaging studies and to rule out secondary injuries associated with the dislocation.

SUGGESTED READINGS

1-Leggit JC, Meko CJ.Acute finger injuries: Part I.Tendons and ligaments. Am Fam Physician.2006;73(5):810–816.

2-Leggit JC, Meko CJ.Acute finger injuries: Part II.Fractures, dislocations, and thumb injuries.Am Fam Physician. 2006;73(5):827–834.

3-Zemel NP. Metacarpophalangeal joint injuries in fingers.Hand Clin. 1992;8(4):745–754.