Fracture, Carpal Bone (Other)

By admin On Dec 4, 2023

Ovid: 5-Minute Sports Medicine Consult, The

Thomas Trojian

Deena C. Petrocelli

Basics

Description

Fracture of the carpal bones of the wrist, excluding those of the hamate and scaphoid
Includes Kienböck disease, a disease of the lunate where the blood supply is compromised and possible osteonecrosis occurs
Synonym(s): Wrist fracture

Epidemiology

The carpal bones consist of the scaphoid, lunate, triquetrum, and pisiform in the proximal row and the trapezoid, trapezium, capitate, and hamate in the distal row.
Since 1990, 8–19% of hand injuries have resulted in a carpal fracture.
Frequency of fracture seen in carpal bones is scaphoid 80%, triquetrum 6%, hamate 5%, trapezium 4%, lunate 3%, capitate 1%, and trapezoid and pisiform, <1% each.
Carpal fractures are caused by trauma from either a fall on the extended wrist or a direct blow.
Kienböck disease in 75% of the cases is preceded by severe trauma with the wrist in extreme dorsiflexion.

Risk Factors

Fractures of the carpal bones other than the scaphoid and lunate bones are often seen in sports using a stick (eg, hockey, lacrosse).

Diagnosis

History

Athlete usually will present with a fall on the outstretched hand in the hyperextended position. However, direct trauma or a fall on a flexed wrist can also cause a fracture. Pain and restricted motion often are presenting complaints.
Mechanism of injury can help localize the injury to a specific carpal bone.
Determine when the wrist began to hurt; recent vs prolonged is important.
Determine location of pain, whether ulnar or radial, at rest or with motion.
An occult fracture often will present as a persistent wrist sprain. Carefully examine the patient, as Kienböck disease and small chip fractures of the triquetrum can present in this manner.

Physical Exam

Pain and tenderness over the dorsum of the wrist
Localized swelling and limited range of motion; a prominence may be present.
Strength testing of the muscles whose tendons insert on or are supported by the injured structure may help localize the injury.
Neurovascular signs are unusual, except for fracture of the pisiform, which may affect the ulnar nerve and artery.
Inspect for swelling, deformity, and ecchymosis (the latter usually not seen with carpal fractures).
Evaluate movement of wrist in flexion, extension, and ulnar and radial deviation.
Palpate individual carpal bones to determine location of tenderness.
Test strength of muscles that attach to carpal bones.
Assess neurovascular integrity (fracture of the pisiform may affect the ulnar nerve and a lunate dislocation may compress the median nerve).
Axial loading of metacarpals above the carpal bones may help in diagnosis.

Diagnostic Tests & Interpretation

Imaging

Radiographs consisting of 6 views: Anteroposterior (AP) and lateral, each taken in an exact neutral position; motion views of maximal radial deviation and maximal ulnar deviation; lateral views in maximal flexion and maximal extension
Additional radiographic views may be needed if a fracture is suspected for certain carpal bones: Pisiform (carpal tunnel views, oblique view with forearm in 20 degrees supination), triquetrum (slightly oblique, pronated lateral view), trapezium (carpal tunnel views and true AP [Robert] view), and trapezoid (oblique views)
CT scanning should be considered if a fracture of the capitate, lunate, pisiform, trapezium, or trapezoid is suspected and negative plain films are seen.
Postreduction views should be obtained to confirm reduction and correct anatomical alignment.

Differential Diagnosis

Ligamentous injury (wrist sprain)
Contusion
Carpal dislocation
Metacarpal fracture
Distal radioulnar fracture

Treatment

Immobilization of the wrist should eliminate the pain of the fracture.
NSAIDs or narcotics can be added as needed.
There are theoretical concerns about the adverse effects of NSAIDs on fracture healing; there is not enough clinical evidence to deny patients with simple fractures their analgesic benefits.
Reduction techniques should not be necessary. All displaced or dislocated fractures should be splinted and referred for surgery.
Lunate dislocation may need immediate reduction if median nerve or artery is involved.
All treatments are for nondisplaced fractures.
Triquetrum: Short arm cast for 4–6 wks for transverse body fracture; short arm cast or splint for 2–4 wks for dorsal avulsion
Trapezium: Short arm thumb spica cast for 4–6 wks
Pisiform: Short arm cast or splint for 3–6 wks
Trapezoid: Short arm thumb spica cast for 4–6 wks
Capitate: Short arm thumb spica cast for 6–8 wks. Some recommend long arm with finger extension. Consider referral because of possible avascular necrosis (AVN).
Lunate: Short arm cast, or at least splint until referred; prolonged immobilization of 12–16 wks, may need long arm cast with finger extension.

Additional Treatment

Additional Therapies

Triquetrum:
- 2nd most commonly fractured carpal bone
- Dorsal rim chips of the triquetrum are easily missed on AP view and may be the only sign of a fracture.
- May have tenderness distal to the ulnar styloid while the hand is in radial deviation
- Persistent pain after appropriate treatment should alert the treating physician that a concurrent injury (pisiform fracture, triangular fibrocartilage complex injury, and/or lunate-triquetrum ligament tear) was initially not noticed.
Capitate:
- Most often fractured with the scaphoid or metacarpal
- Consider all capitate fractures unstable because of the high likelihood of surrounding carpal instability.
- Consider serial radiographs in patients with persistent pain.
- High incidence of delayed nonunion in these fractures
- Referral to hand specialist is reasonable.

P.177

Trapezium:
- Easily missed; patients will describe a localized pain at base of the thenar eminence and pain with wrist flexion.
- Missed fractures cause ongoing pain at base of the thumb.
- Carpal tunnel view demonstrates fracture of the palmar ridge.
- When displaced, may affect the integrity of the trapeziometacarpal joint, which is responsible for pinch and grasp motions.
Pisiform:
- Sesamoid bone located within the flexor carpi ulnaris tendon, which can be disrupted if a fracture is present
- Usually caused by direct blow to hand
- Can compress the ulnar nerve or artery at Guyon's canal
- The pisiform can be excised in chronically symptomatic cases.
Trapezoid:
- Least commonly fractured
- Patients describe pain at the base of the second metacarpal.
- Axial compression of second metacarpal will elicit tenderness.
Lunate:
- Lunate fractures can be occult.
- AVN is seen in 20% of lunate fractures.
- Kienböck disease may be secondary to lunate injury.
- Kienböck disease has a high association with ulna-minus variant.
- In the early stages of Kienböck disease, plain radiographs are usually not diagnostic; MRI is usually needed for definitive diagnosis.
- Referral to hand specialist is reasonable.
Initially, while in cast, the athlete needs to continue fitness training. Constant monitoring of the cast and frequent (weekly) changes may be needed to maintain skin and cast integrity.
Once out of the cast, range of motion (ROM) then strengthening of the wrist need to be done until restoration of a painless, functional arc of wrist motion and near-normal strength are obtained.

Surgery/Other Procedures

Surgery is needed for displaced fractures(s) through the metacarpocarpal joint articulation.

Ongoing Care

Follow-Up Recommendations

Any displaced fracture of the carpal bones should be referred to an orthopedic surgeon.
Lunate fractures may develop AVN (avascular necrosis, Kienböck disease) and should be considered for referral even if not displaced.

Additional Reading

Cooney WP III, Linscheid RL, Dobyns JH. Fractures and dislocations of the wrist. In Rockwood A Jr, Green DP, eds. Rockwood and Green's fractures in adults, 4th ed. Philadelphia: Lippincott-Raven Publishers, 1996:822–827.

Culver JE, Anderson TE. Fractures of the hand and wrist in the athlete. Clin Sports Med. 1992;11:101–128.

DeHaven KE, Lintner DM. Athletic injuries: comparison by age, sport, and gender. Am J Sports Med. 1986;14:218–224.

Eisenhauer MA. Wrist and forearm. In: Rosen P, ed. Emergency medicine: concepts and clinical practice, 4th ed. St. Louis: Mosby-Year Book, 1998:673–677.

Geissler WB. Carpal fractures in athletes. Clin Sports Med. 2001;20:167–188.

Papp S. Carpal bone fractures. Orthop Clin North Am. 2007;38:251–260.

Rettig AC. Epidemiology of hand and wrist injuries in sports. Clin Sports Med. 1998;17:401–406.

Rettig ME, Dassa GL, Raskin KB, et al. Wrist fractures in the athlete. Distal radius and carpal fractures. Clin Sports Med. 1998;17:469–489.

Slade JF, Milewski MD. Management of carpal instability in athletes. Hand Clin. 2009;25:395–408.

Vigler M, Aviles A, Lee SK. Carpal fractures excluding the scaphoid. Hand Clin. 2006;22:501–516; abstract vii.

Wright PE II. Wrist. In: Canale T, ed. Campbell's operative orthopaedics, 9th ed. St. Louis: Mosby, 1998:3455–3476.

Codes

ICD9

814.00 Closed fracture of carpal bone, unspecified
814.02 Closed fracture of lunate (semilunar) bone of wrist
814.03 Closed fracture of triquetral (cuneiform) bone of wrist

Clinical Pearls

Return to play varies with the degree of injury and casting. In lunate fractures, it is up to 6 mos; in triquetrum fractures, it is 4 wks, possibly less, in cast. General requirements for returning to play are complete healing of the fracture and any concurrent soft tissue injuries. Thorough rehabilitation with restoration of a painless, functional arc of wrist motion and near-normal strength are essential.
Wrist stiffness is a common problem after casting, and physical therapy for ROM and strengthening is essential after cast removal. When rehabilitation is done, the wrist is most often free of pain.