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LUNATE FRACTURE

Introduction

Fracture Nomenclature for Lunate Fracture

Hand Surgery Resource’s Diagnostic Guides describe fractures by the anatomical name of the fractured bone and then characterize the fracture by the Acronym:

In addition, anatomically named fractures are often also identified by specific eponyms or other special features.

For the Lunate Fracture, the historical and specifically named fractures include:

Perilunate dislocation and fracture-dislocation

Lunate dislocation and fracture-dislocation

By selecting the name (diagnosis), you will be linked to the introduction section of this Diagnostic Guide dedicated to the selected fracture eponym.

Fractures of the carpal bones account for ~6% of all fractures and up to 18% of all hand fractures. The vast majority (58-89%) occurs in the scaphoid, while fractures of the other 7 carpals are rare, accounting for ~1.1% of all fractures. The incidence of lunate fractures is estimated to be from 0.5-6.5% of all carpal fractures. Rarely seen in isolation, lunate fractures are usually concomitant with other carpal injuries—especially of the scaphoid—and occur in conjunction with a perilunate fracture-dislocation in 5-7% of wrist injuries. Lunate fractures are often associated with avascular necrosis(AVN) of the lunate. The most common mechanism of injury is a fall on an outstretched hand (FOOSH) with a dorsiflexed, ulnarly-deviated wrist that drives the capitate down into the lunate. Lunate fractures are difficult to treat, and there is some controversy and a lack of consensus regarding the management of several injury patterns, but it appears that surgery is frequently required and associated with better outcomes than conservative strategies.1-5

Definitions

  • A lunate fracture is a disruption of the mechanical integrityof the lunate.
  • A lunate fracture produces a discontinuity in the lunate contours that can be complete or incomplete.
  • A lunate fracture is caused by a direct force that exceeds the breaking point of the bone.

Hand Surgery Resource’s Fracture Description and Characterization Acronym

SPORADIC

S – Stability; P – Pattern; O – Open; R – Rotation; A – Angulation; D – Displacement; I – Intra-articular; C – Closed

S - Stability (stable or unstable)

  • Universally accepted definitions of clinical fracture stability is not well defined in the hand surgery literature.6-8
  • Stable: fracture fragment pattern is generally nondisplaced or minimally displaced. It does not require reduction, and the fracture fragment’s alignment is maintained with simple splinting. However, most definitions define a stable fracture as one that will maintain anatomical alignment after a simple closed reduction and splinting. Some authors add that stable fractures remain aligned, even when adjacent joints are put to a partial range of motion (ROM).
  • Unstable: will notremain anatomically or nearly anatomically aligned after a successful closed reduction and simple splinting. Typically unstable lunate fractures have significant deformity with comminution, displacement, angulation, and/or shortening.
  • Isolated dorsal lunate dislocations can be unstable, even if there is no associated lunate fracture.9

P - Pattern

  • Lunate dorsal pole (lip): may result from scapholunate or lunotriquetral interosseous or dorsal radiocarpal ligament avulsion; impingement of the dorsal pole between the radius and capitate during extreme wrist dorsiflexion can also produce an impaction fracture1
    • An avulsion fracture may occur because the dorsal pole serves as the attachment point of several major ligaments.10
  • Lunate volar pole (lip): may result from avulsion of the long and/or short radiolunate ligaments1
    • An avulsion fracture may occur because the volar pole also serves as the attachment point of several major ligaments10
  • Lunate body: sagittal, coronal, transverse, and/or comminuted2-4
    • Often occur secondary to axial loading of the lunate between the capitate head and lunate fossa1
  • One classification system uses the following 5 groups to categorize lunate fractures:
    • Group I: volar pole fractures
    • Group II: chip fractures
    • Group III: dorsal pole fractures
    • Group IV: sagittal fractures through the body
    • Group V: transverse fractures through the body4,11
  • Osteochondral and transarticular body fractures of the lunate are also possible.2

O - Open

  • Open: a wound connects the external environment to the fracture site. The wound provides a pathway for bacteria to reach and infect the fracture site. As a result, there is always a risk for chronic osteomyelitis. Therefore, open fractures of the lunate require antibiotics with surgical irrigation and wound debridement.6,12,13
  • ~10% of perilunate dislocations and fracture-dislocations are open injuries, and 26% are associated with polytrauma.14
  • High-energy injuries that involve open perilunate dislocations and a devascularized lunate have been found to be capable of healing with acceptable wrist function and revascularization.15
  • Under the Herzberg classification system, perilunate dislocations are considered stage I injuries, and lunate dislocations are stage II. Lunate dislocations are further classified as stage IIA when the lunate has subluxated out of its fossa but has rotated <90° and as stage IIB when lunate rotation is >90°.18,19
  • Open fractures of the lunate may require surgical exploration to determine if articular surfaces are involved. After irrigation and debridement, these wounds are generally closed if the joint and fracture contamination has been elliminated.  When there is doubrt the would is left open and secondary I&D's are done and the wound is closed when htere is no sign of infection.16,17

R - Rotation

  • Lunate fracture deformity can be caused by rotation of the distal fragment on the proximal fragment.
  • Degree of malrotation of the fracture fragments can be used to describe the fracture deformity.
    • If an offending force is sufficient enough—such as from a FOOSH with extreme dorsiflexion and ulnar deviation—the lunate will dislocate and rotate volarly, which is the final stage of a perilunate dislocation.20
    • In lunate dislocations, the spilled teacup sign seen on the lateral radiograph is created by proximal rotation of the lunate about its attached volar ligaments. If the lunate rotates >90°, it is seen as a triangular shape rather than its normal quadrilateral shape and appears absent from its normal location on an anteroposterior (AP) radiographic view.18,21

A - Angulation (fracture fragments in relationship to one another)

  • Angulation is measured in degrees after identifying the direction of the apex of the angulation.
  • Straight: no angulatory deformity
  • Angulated: bent at the fracture site
  • In this small carpal bone signficant angulation is rare.

D - Displacement (Contour)

  • Displaced: disrupted cortical contours
  • Nondisplaced: fracture line defining one or several fracture fragments; however, the external cortical contours are not significantly disrupted
  • In lunate dislocations, the lunate becomes displaced as it rotates volarly, while the rest of the carpal bones remain in normal anatomic position in relation to the radius.21
  • Radiocarpal instability is usually displaced in a dorsoradial direction, while midcarpal instability is usually displaced in a volar direction.5
  • Volar or dorsal pole fractures may be displaced, and the hallmark sign is translation of the capitate in the respective direction of the affected pole.2

I - Intra-articular involvement

  • Fractures that enter a joint with one or more of their fracture lines.
  • Lunate fractures can have fragment involvement with the radius or any of its intercarpal joint articulations.
  • If a fracture line enters a joint but does not displace the articular surface of the joint, then it is unlikely that this fracture will predispose to posttraumatic osteoarthritis. If the articular surface is significantly separated, or there is a step-off in the articular surface, then the congruity of the joint will be compromised and the risk of posttraumatic osteoarthritis increases significantly.
  • Transverse translunate fracture-dislocations are intra-articular fractures of the lunate.22

C - Closed 

  • Closed: no associated wounds; the external environment has no connection to the fracture site or any of the fracture fragments.6-8

Lunate fractures: named fractures, fractures with eponyms, and other special fractures

Perilunate dislocation and fracture-dislocation

  • Dislocations of the lunate are typically divided into perilunate and lunate varieties.23
  • Perilunate dislocations and perilunate fracture-dislocations comprise a spectrum of challenging injury patterns that typically occur after a fall from a height, motor vehicle accident, or injury during sporting activities.18
  • The majority of perilunate dislocations are dorsal, with only 3% being volar, and these injuries involve a dorsal dislocation of the capitate with respect to the lunate, while the lunate remains in its normal position in the lunate fossa.18,22
    • Perilunate dislocation is the most common pattern of carpal dislocation.9
    • These are devastating high-energy injuries that are commonly seen after a FOOSH in extremes of dorsiflexion and ulnar deviation.
    • The arc that the dislocating torque follows has been described: it begins with disruption of the scapholunate ligament or fracture of the scaphoid followed by lunatocapitate disruption and then by disruption of the lunatotriquetral ligament. Eventually, if the force is sufficient, the lunate dislocates and rotates volarly, which is the final stage of perilunate dislocation.20
  • Perilunate fracture-dislocations are frequently seen in the literature and combine ligament ruptures, bone avulsions, and fractures in a variety of clinical forms. The most common is the transscaphoid perilunate dislocation, while variants of this pattern include those associated with fractures of the capitate, triquetrum, lunate, distal radius, radial styloid, and ulnar styloid.3,24
    • Lunate fractures occur in conjunction with a perilunate fracture-dislocation in 5-7% of wrist injuries, and the latter usually occur among men aged 20-30 years after a fall from a significant height, a motor vehicle accident or motorcycle accident involving high kinetic energy.25,26
  • ~10% of perilunate dislocations and fracture-dislocations are open injuries, and 26% are associated with polytrauma.14
  • Perilunate injuries are considered to be a greater or lesser arc depending on the presence of associated carpal fractures or ligamentous disruptions.5
    • A greater arc injury is one with an associated fracture of one or more bones around the lunate, while a lesser arc injury is associated with pure ligamentous disruption around the lunate.20
    • Similarly, translunate fracture-dislocations are often part of a more significant carpal injury, and the translunate arc concept describes lunate fractures as a variant of the lesser and greater arc injuries.5
  • Translunate arc describes rare, usually high-energy injuries in which a perilunate dislocation occurs with a lunate fracture, which further destabilizes the carpus.18
  • The Mayfield et al. classification system for perilunate injuries and carpal instability is commonly used to better inform treatment decisions:
    • Stage I: scapholunate dissociation, with failure of the scapholunate or radioscaphocapitate ligament
    • Stage II: perilunate dislocation, in which the capitolunate joint is disrupted; ~60% are associated with scaphoid fractures
    • Stage III: midcarpal dislocation, which includes disruption of the triquetrolunate interosseous ligament or triquetral fracture; neither the capitate or the lunate is aligned with the distal radius
    • Stage IV: lunate dislocation from the lunate fossa, which usually occurs in a volar direction and involves a failure of the radiocarpal ligament27
    • Stage V: complete volar lunate dislocation with a carpal fracture. This tytpe described by Cooney et al.28 is the most severe type of perilunate fracture-dislocation
  • Another classification system by Herzberg et al. expands on the Mayfield system to include rotational details:
    • Stage I: Mayfield stages I-III
    • Stage II: Mayfield stage IV
    • Stage IIA: Mayfield stage IV with lunate dislocated volarly and rotated <90°
    • Stage IIB: Mayfield stage IV with lunate dislocated volarly and rotated >90°19

Imaging

  • Diagnosis is difficult, as clinical symptoms are nonspecific on account of the lunate having the largest cartilage-covered area of all the carpals.
    • It has been found that up to 25% of perilunate dislocations and fracture-dislocations are missed on clinical and radiographic examination. Failing to properly diagnose these injuries can lead to a delay in management and unfavorable outcomes.3,18
  • Standard wrist posteroanterior (PA) and lateral radiographs are most useful.
    • The PA view should be scrutinized for uneven gapping in the carpal bones, and the 3 smooth carpal arcs of Gilula should be free of discontinuity.
    • These injuries are often seen on PA radiographs as a loss of carpal height with overlapping of the carpal bones, particularly the capitate and lunate.
    • On lateral radiographs, the hallmark sign is a loss of colinearity of the radius, lunate, capitate and metacarpals.18
  • A CT scan may be needed if there is any doubt and in order to avoid a delay in diagnosis.
    • Can determine the type of fracture(s), the amount of displacement, degree of comminution, if there are any associated ligament injuries, and to identify an occult fracture.18,22
    • Particularly helpful for detecting occult greater arc injuries.20
  • MRI without contrast is effective for identifying intercarpal ligamentous ruptures and occult fractures or bone contussions. MRIs are therefore more useful for lesser arc injuries.18,20

Treatment

  • Perilunate dislocations and fracture-dislocations should be considered emergencies that require prompt intervention to increase the chances of a positive outcome.20
  • These injuries were historically managed with closed reduction and casting, and some clinicians continue to treat these injuries conservatively today, but these methods have been found to result in unsatisfactory outcomes. This is why the current standard is closed reduction followed by open reduction and internal fixation (ORIF) that includes ligamentous and bony repair.18,20
    • The first step of treatment is immediate, gentle, closed reduction, which is needed to decrease pressures on critical neurovascular structures and cartilage. Reduction is performed with the elbow flexed to 90° and the hand placed into finger traps.
  • Stable closed reduction is typically achieved, with reported maintenance of reduction in >90% of cases, and significant muscle relaxation improves the chances for a successful closed reduction.
    • Open reduction, ligament and bone repair, and supplemental fixation are typically performed within 3-5 days afterwards as swelling subsides.
  • The surgical maxim for greater arc injuries is fixation of the bony involvement before soft-tissue repair. Scaphoid fractures are typically fixed using cannulated headless screw systems, while comminuted fractures can be treated with K-wire fixation and autologous bone grafting from the distal radius.
  • Fixation is then followed by a period of cast immobilization.18
    • For perilunate fracture-dislocations with a transverse lunate fracture, a dorsal approach is typically used to reduce the intra-articular fracture of the lunate and reduce the scapholunate and lunotriquetral diastasis by ligament reattachment and temporary K-wire pinning.22
  • Carpal tunnel syndrome has been frequently identified in delayed presentations of volar lunate dislocations, and carpal tunnel release is frequently needed in these cases if any median nerve symptoms are present.9
  • Closed reduction and percutaneous pinning (CRPP) may also be used for perilunate dislocations, while arthroscopy is another surgical option for perilunate fracture-dislocations.18,22

Complications

  • Posttraumatic osteoarthritis
  • Median nerve dysfunction
  • Complex regional pain syndrome
  • Hand or wrist weakness
  • Tendon ruptures/dysfunction
  • Residual carpal instability
  • Infection
  • Nonunion 
  • Malunion
  • Avascular necrosis (AVN) or transient ischemia of the lunate

Outcomes

  • Perilunate dislocations and fracture-dislocations are severe injuries with a poor prognosis for return to full previous function.
    • Open injuries, those with delayed treatment, those with osteochondral fractures of the capitate head, and the presence of persistent carpal malalignment all imply poorer outcomes, while outcomes are improved by early, accurate reduction and stable internal fixation.18
  • One study of 28 perilunate dislocations with scaphoid fractures treated with early open reduction, ligamentous repair, and cast immobilization led to satisfactory results.22
  • In another study of 32 patients with a perilunate dislocation or fracture-dislocation treated with closed reduction and immobilization, more than half failed to maintain reduction.29
  • A comparison trial of 28 patients with perilunate dislocation or fracture-dislocation found that 12 of 20 wrists managed with ORIF had good or excellent results, while the 8 treated with closed reduction and casting had fair or poor outcomes.30
  • Reports of acceptable results with ORIF have also been published when treatment was delayed for up to 6 months.31,32

Lunate dislocation and fracture-dislocation

  • Although the two entities should be viewed and addressed separately, it is generally agreed that lunate and perilunate dislocations and fracture-dislocations are different stages of the same injury pattern.18,23,33
    • To differentiate, the lunate is displaced and rotated volarly in lunate dislocations, while the rest of the carpal bones are in a normal anatomic position in relation to the radius. In perilunate dislocations, the radiolunate articulation is preserved and the rest of the carpus is displaced dorsally.18
    • Based on the Herzberg classification system, all perilunate injuries are considered stage I, while all lunate injuries are stage II.19
    • Dislocation of the lunate is usually in the volar direction, while dorsal, isolated dislocations of the lunate are extremely rare and usually associated with concomitant fractures of other carpal bones or the distal radius.9
    • Volar lunate dislocation can be classified as Herzberg stage II and are considered the final stage of the perilunate fracture-dislocation spectrum.33
  • However, a complete volar lunate dislocation combined with a carpal fracture is the most severe type of perilunate fracture-dislocation, which is considered Mayfield stage V.33
  • Lunate dislocations are commonly associated with fracture of one or more other carpal bones, and as with perilunate dislocations, the scaphoid is most commonly involved.9,34
  • In these injuries, the capitate has reduced from its dorsally dislocated position to become colinear with the radius, dislocating the lunate into the carpal tunnel.18

Imaging

  • In lunate dislocations, an anteroposterior (AP) radiographic view shows the lunate as absent from its normal location with a large gap in this region. If the lunate rotates >90°, it is seen as a triangular shape rather than its normal quadrilateral shape.
  • On the lateral radiograph, the lunate appears displaced volarly and is usually rotated in lunate dislocations. A search for the head of the capitate reveals that it does not articulate as it should with the lunate.21
  • A CT scan or MRI may be needed in some cases that are difficult to diagnose.

Treatment

  • Treatment for lunate dislocations and fracture-dislocations is somewhat controversial, but most agree that surgery is always necessary and that closed reduction is only appropriate as an initial treatment for Herzberg stage IIA injuries—volar lunate dislocations rotated <90°. Prompt surgical intervention appears to be necessary for all stage IIB injuries, open injuries, and whenever adequate reduction is not possible or difficult to maintain.5,18,34
  • Most experts also agree that lunate fracture-dislocations are complex injuries that require stabilization of the lunate and of any associated fractures and/or ligament injuries.5
  • Closed reduction for stage IIA lunate dislocations begins with wrist flexion to release tension on the volar ligaments, and is followed with dorsally directed pressure placed on the lunate to reduce it into the lunate fossa.
    • After reduction, the wrist is extended, traction is exerted, and the wrist is flexed, all while maintaining a volar buttress with a digit to the lunate. This maneuver should relocate the capitate back onto the recently reduced lunate stabilized by volar pressure.
    • Once this is completed, the injured extremity is placed in neutral rotation into a sugar tong splint to allow elevation and full ROM of the fingers. If an acceptable, stable reduction is achieved, surgery is typically performed 3-4 days later when swelling has improved.18
  • Internal fixation with K-wires, external fixation with K-wires, arthroscopy, and open surgery have all been discussed in the literature as surgical options for these injuries, but research on outcomes and optimal management strategies is scarce.34
    • Lunate fracture-dislocations may also require a neutralization device such as a bridging plate to prevent loss of fixation and collapse of the carpus.5
  • The rare isolated, dorsal lunate dislocation may also respond well to closed reduction and K-wire fixation alone, followed by a short period of cast immobilization.9

Complications

  • Posttraumatic osteoarthritis
  • Median nerve dysfunction
  • Complex regional pain syndrome
  • Hand or wrist weakness
  • Tendon ruptures/dysfunction
  • Residual carpal instability
  • Infection
  • Nonunion 
  • Malunion
  • Transient ischemia of the lunate

Outcomes

  • In one study, lunate fracture-dislocations were associated with a poor prognosis and high risk of complications: of the 14 patients with this injury, 8 had nonunion, developed avascular necrosis, or required an early or late salvage procedure.5

Related Anatomy

  • The lunate is located in the center of the proximal row of the carpus. It consists of a body and a volar and dorsal pole, which are the attachment points of several major ligaments and help give the bone the crescent shape it’s named for. Its distal aspect is concave and articulates with the capitate, while proximally it articulates with the lunate facet of the distal radius, laterally with the scaphoid, and medially with the triquetrum. In some patients, the lunate also articulates with the hamate distally/medially by a long, narrow facet.10,35
    • Along with the scaphoid and triquetrum, the lunate also forms the distal articular surface of the radiocarpal joint.
    • Since it resides within the lunate fossa, a protected concavity of the distal radius, the lunate can be considered a “carpal keystone.” It is also integral in the flexion/extension arc and the radial/ulnar deviation arc at both the radiocarpal and midcarpal joints.35
  • Ligamentous attachments of the lunate include the scapholunate, lunotriquetral, lunatocapitate, radiolunotriquetral, radioscapholunate, ulnolunate, and radiolunate ligaments.9
    • The ulnocarpal ligamentous complex consists of the ulnolunate, ulnotriquetral, and ulnocapitate ligaments. It merges firmly with the volar radioulnar ligament and plays an important role in maintaining the stability of the distal radioulnar joint through the triangular fibrocartilage complex. Impairment of the ulnolunate ligament can therefore cause chronic ulnar wrist pain.10
  • The lunate does not have any tendinous attachments.
  • Of all the carpal bones, the lunate bone has proportionally the largest cartilage-covered area, and its proximal portion is made up almost completely of articular cartilage with no soft tissue attachment and a poor blood supply.35

Incidence and Related injuries/conditions

  • Fractures of the carpal bones have been found to account for 8-18% of all hand fractures36,37and ~6% of fractures overall.38
  • Fractures of the proximal carpals are more common than the distal carpals, and the most commonly fractured carpal bone is the scaphoid, which represents 58-89% of all carpal fractures.36,37,39,40
  • Fractures of the other 7 carpals are very rare and only account for ~1.1% of all fractures. The triquetrum ranks highest of these bones, while fractures of the remaining carpals are even less common and vary in incidence.41-43
  • The incidence of lunate fractures is not clearly defined and has been reported to range from 0.5-6.5% of all carpal fractures.11,44. There is some controversy regarding this figure, and it’s been suggested that the higher end of the range may include some overestimations, as some investigators likely included Kienböck’s disease, dorsal triquetral fractures, and/or bipartite lunates in their diagnoses of lunate fractures.1,2
  • Lunate fractures occur in conjunction with a perilunate fracture-dislocation in 5-7% of wrist injuries

Work-up Options

  • Routine X-rays
    • A normal lateral radiograph will show the capitate, lunate, and distal radius collinear with the wrist in a neutral position.35
    • Standard AP, lateral, and oblique radiographs frequently fail to visualize or underestimate the size or displacement of lunate fracture fragments.
  • On the AP view, any widening of the scapholunate space—scapholunate dissociation—is a clue to a possible occult lunate fracture.1,2
    • The hallmark of a displaced volar or dorsal pole fracture of the lunate is translation of the capitate in the respective direction of the affected pole.2
    • When assessing the position of the carpal bones on plain radiographs, Gilula’s lines are a useful point to start from.9
  • CT scan
    • Typically recommended when plain radiographs fail to provide a clear diagnosis and clinical suspicion remains.
    • Will help to provide a greater definition of the fracture configuration and the degree of displacement, and to identify fractures that may be obscured by overlapping carpals on plain radiographs.2
    • Particularly helpful for identifying lunate body fractures.1
  • MRI
    • Considered the best imaging modality for diagnosing lunate fractures, as it clearly visualizes the carpus and has the added ability to detect early vascular compromise within these bones, so it may also identify chondral and ligamentous injuries as well.5
    • Also desirable when radiation needs to be avoided, as in children and pregnant women, and asensitive tool in the follow-up of avascular necrosis and fracture healing.18
  • Bone scan
ICD-10 Codes

  • LUNATE FRACTURE

    Diagnostic Guide Name

    LUNATE FRACTURE

    ICD 10 Diagnosis, Single Code, Left Code, Right Code and Bilateral Code

    DIAGNOSISSINGLE CODE ONLYLEFTRIGHTBILATERAL (If Available)
    FRACTURE CARPAL BONE - LUNATE    
    - DISPLACED S62.122_S62.121_ 
    - NONDISPLACED S62.125_S62.124_ 

    Instructions (ICD 10 CM 2020, U.S. Version)

    THE APPROPRIATE SEVENTH CHARACTER IS TO BE ADDED TO EACH CODE FROM CATEGORY S62
     Closed FracturesOpen Type I or II or OtherOpen Type IIIA, IIIB, or IIIC
    Initial EncounterABC
    Subsequent Routine HealingDEF
    Subsequent Delayed HealingGHJ
    Subsequent NonunionKMN
    Subsequent MalunionPQR
    SequelaSSS

    ICD-10 Reference

    Reproduced from the International statistical classification of diseases and related health problems, 10th revision, Fifth edition, 2016. Geneva, World Health Organization, 2016 https://apps.who.int/iris/handle/10665/246208

Clinical Presentation Photos and Related Diagrams
Lunate Fracture Diagrams
  • Non-displaced lunate fracture (arrow)
    Non-displaced lunate fracture (arrow)
  • Displaced lunate fracture (arrow)
    Displaced lunate fracture (arrow)
  • Non-displaced dorsal lip lunate fracture (arrow)
    Non-displaced dorsal lip lunate fracture (arrow)
Symptoms
History of wrist trauma
Fracture pain, deformity, swelling, crepitus and ecchymosis
Impaired wrist range of motion
Impaired grip strength
Typical History

A typical patient is a 32-year-old, left-handed man who fell off of a 10-foot balcony at an apartment. The man was sitting atop the rail of the balcony and speaking to some friends when he lost his balance and fell backwards. His body rotated in the air and he outstretched both hands to break his fall. His right wrist—which was in dorsiflexion and ulnar deviation—withstood the brunt of the impact, which axially compressed the capitate and drove it into the lunate, resulting in a complex lunate fracture-dislocation.

Positive Tests, Exams or Signs
Work-up Options
Images (X-Ray, MRI, etc.)
Lunate Fracture
  • Lunate dorsal lip fracture (arrow) associated with avascular necrosis (AVN) of the lunate
    Lunate dorsal lip fracture (arrow) associated with avascular necrosis (AVN) of the lunate
Treatment Options
Treatment Goals
  • When treating closed lunate fractures, the treating surgeon has 4 basic goals:6,13
    1. A lunate has a normal appearance. The X-ray may not need to be absolutely perfect, but the lunate should have no obvious deformity (ie, the lunate looks normal!)
    2. Avoid stiffness by obtaining a normal functional ROM after ligament and fracture healing(ie, the wrist works!)
    3. The lunate is not painful (ie, the lunate does not hurt!)
    4. Congruent joint surface with none-to-minimal joint surface irregularities (ie, the joints associated with the lunate do not develop early posttraumatic arthritis!)
    5. Fracture care should minimize the risk for infection and osteomyelitis.
  • One additional goal is mandatory for open fractures:
  • It’s important to recognize translunate injuries, Kienböck’s disease, and bipartite lunate, as well as the presence of any other associated carpal fractures and/or instabilities before developing a management strategy.2,5
Conservative
  • Due to the rarity of lunate fractures, there is no universal consensus on the optimal treatment for them in the acute or chronic setting.3,4
  • Treatment recommendations for isolated lunate fractures depend on the amount of displacement, fracture site, and the impact of fracture on vascularity and ligamentous stability.4
  • Conservative treatment is typically recommended for traumatic nondisplaced, minimally displaced, and small avulsion fractures of the lunate, as well as fractures without any subluxation.2,35  In most cases these injuries are managed with cast immobilization for 4-6 weeks until bony union is achieved.2,4,35
  • Lunate fractures should be approached with caution because even seemingly innocuous, isolated fractures may functionally detach critical wrist ligaments and lead to profound malalignment of the carpus, or be part of a larger ligamentous insult. Therefore, patients treated conservatively require meticulous follow-up care to ensure that wrist malalignment does not develop.1. The patient should be advised that the treatment plan may have to bechanged and open repair performed if the initial reeduction is lost.
Operative
  • Surgical treatment of lunate fractures must always be an individualized therapeutic decision. However, surgical lunate fracture care is most frequently recommended when:
    1. Closed reduction fails or the simple splint or cast immobilization does not maintain the reduction. For these irreducible or unstable fractures, operative treatment is recommended to achieve the 4 treatment goals of fracture care.
    2. There is a significantly displaced lunate fracture fragment involving one of its associated joints. Surgical fracture care may be required in these cases.
    3. Open lunate fractures require surgical care in the form of irrigation and debridement to prevent chronic infection.
  • As with conservative treatment, there is little consensus on the ideal approach for surgically managing lunate fractures, but most experts agree that surgery is needed when the lunate fracture is displaced and/or associated with other fractures.2,4,5
  • Displaced lunate fractures typically require immediate anatomic reduction using ORIF. If sufficient bony purchase can be achieved, headless screw fixation is the most commonly used technique, but K-wire stabilization to the adjacent carpals may be needed if the comminution is substantial or fracture fragments are too small.2-4. When fixation is needed of both the lunate and the carpus in these cases, it’s important that the lunate is stabilized first and then the carpus stabilized around it because of its central role as a keystone of the wrist.5. ORIF is also recommended for most volar chip fractures to preserve the lunate vascular supply and restore its ligamentous attachments.2
  • In addition to the lunate fracture, ligamentous attachments including the scapholunate and lunotriquetral ligaments should be assessed to detect for the presence of avulsion fracture at one or both of the poles.  Volar pole fractures require reduction and fixation because they produce functional loss of the long and short radiolunate ligaments, and may produce profound volar flexion and dorsal translation of the lunate if left untreated.  Large dorsal pole fractures also require fixation because they can produce functional loss of the dorsal component of the scapholunate interosseous, dorsal radiocarpal, and lunotriquetral ligaments.1,2
  • If there are multiple carpal injuries or the patient presents in a delayed fashion with chronic carpal instability and osteoarthritis, salvage procedures such as proximal row carpectomy and wrist arthrodesis may be required.3,10
CPT Codes for Treatment Options

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CPT Code References

The American Medical Association (AMA) and Hand Surgery Resource, LLC have entered into a royalty free agreement which allows Hand Surgery Resource to provide our users with 75 commonly used hand surgery related CPT Codes for educational promises. For procedures associated with this Diagnostic Guide the CPT Codes are provided above. Reference materials for these codes is provided below. If the CPT Codes for the for the procedures associated with this Diagnostic Guide are not listed, then Hand Surgery Resource recommends using the references below to identify the proper CPT Codes.

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CPT 2021 Professional Edition: Spiralbound

Hand Therapy

Post-treatment Management

  • The care and precautions related to immobilization devices for the lunate fracture must be carefully reviewed with the patient. Patients should be educated regarding care and precautions. Patients should know that pain, especially increasing pain, numbness, tingling, skin irritation, splint loosening, or excessive splint tightness are red flags and should be reported to the surgeon or his team.
  • Pain is initially managed by immobilization in a cast or splint.  Reassurance, elevation, ice in the initial post-fracture period, and mild pain medications should be used. Patients should be encouraged to discontinue pain medication as soon as possible. Opioid use should be kept to a minimum.
  • For perilunate dislocations and fracture-dislocations, postoperative care typically begins with placement of a short arm thumb spica splint in the operating room, with transition to a short arm thumb spica cast at 10-14 days.
  • Patients should be instructed to carefully exercise all joints in the injured hand, wrist, and arm that do not require immobilization.Patients usually can exercise on their own; however, signs of generalized hand or wrist stiffness are indications for referral to hand therapy (PT or OT).
    • Initial rehabilitation focuses on active movement of the shoulder, elbow, and fingers to prevent stiffness.
    • At 6-8 weeks postoperatively, the cast is removed, and a thermoplastic static wrist and thumb splint, with free motion of the thumb interphalangeal joint, is fabricated for protective wear between exercise sessions.
    • After K-wire removal, active, active-assisted, and gentle passive ROM exercises are initiated at the wrist, forearm, and thumb. 
    • At 8-10 weeks postoperatively, passive ROM exercises with unrestricted extension are initiated, with supplemental use of dynamic wrist splinting or weighted wrist stretches, as tolerated.
    • As early as 12 weeks after surgery, some patients can be returned to unrestricted use of the hand in daily activity, with progressive return to sport or work conditioning.18
  • If an infection does occur, management should focus on eradicating sepsis with thorough debridement, appropriate antibiotics, and fracture stabilization, followed by obtaining fracture union and regaining a functional extremity.16
Complications
  • Kienböck’s disease, which is avascular necrosis of the lunate, may develop in some lunate fractures because of the bone’s poor blood supply, and the risk appears to be highest in volar pole fractures.35
  • Other complications associated with lunate fractures include nonunion, carpal instability, carpal malalignment, compartment syndrome, and posttraumatic osteoarthritis.1,2
  • Failure to recognize and treat volar pole fractures can produce chronic palmar subluxation of the capitate and midcarpal arthritis, while failing to properly manage dorsal lunate avulsion fractures can lead to dorsal intercalated collapse instability of the wrist.1
Outcomes
  • Outcomes for lunate fractures are variable, but the likelihood of a positive outcome appears to be higher when there is no subluxation or dislocation. Surgical interventions also seem to have a better success rate than conservative strategies for most lunate fractures.5,18,20,29,30
  • Long-term outcomes for lunate fractures are also influenced by patient age, related injuries, amount of articular damage, development of avascular necrosis, and several other factors.35
Key Educational Points
  • The functional needs of each patient must be considered when recommending treatment for lunate fractures.
  • Although non-scaphoid carpal bones like the lunate have received considerably less attention than the scaphoid, these injuries can still produce morbidity that is disproportionate to their incidence for 2 primary reasons:
    1. These fractures may have a subtle clinical and radiographic presentation and are easily overlooked or misdiagnosed, in some cases as wrist sprains. This can lead to suboptimal management and poor long-term outcomes with significant wrist disability.
    2. These fractures are often harbingers of significant ligamentous disruption or associated carpal fractures, and failure to recognize a more global injury pattern can result in undertreatment and permanent wrist dysfunction.1
  • Associated carpal fractures are very common with lunate fractures, and there is a spectrum of associated carpal instabilities, which can be at the radiocarpal or midcarpal joint, in either volar or radiodorsal directions.5
  • Since lunate fractures and dislocations are serious injuries that require prompt attention, patients with wrist injuries should not be diagnosed with a sprain and released from the emergency department until the physician is confident with their radiographic interpretation.21
  • Although the congenital anomaly bipartite lunate is seen rarely, clinicians must remain suspicious of it in order to avoid an incorrect diagnosis of lunate fracture, which tends to occur because the anomaly can become symptomatic spontaneously or after trauma.4
References

New and Cited Articles

  1. Shah MA, Viegas SF. Fractures of the carpal bone excluding the scaphoid. J Hand Surg Am 2002; 2(3): 129-140
  2. Suh N, Ek ET, Wolfe SW. Carpal fractures. J Hand Surg Am2014;39(4):785-91. PMID: 24679911
  3. Hsu AR, Hsu PA. Unusual case of isolated lunate fracture without ligamentous injury. Orthopedics2011;34(11):e785-9. PMID: 22049967
  4. Saberi S, Arabzadeh A, Farhoud AR. Lunate Osteochondral Fracture Treated by Excision: A Case Report and Literature Review. Trauma Mon2016;21(2):e22378. PMID: 27626007
  5. Shunmugam M, Phadnis J, Watts A, Bain GI. Lunate fractures and associated radiocarpal and midcarpal instabilities: a systematic review. J Hand Surg Eur Vol2018;43(1):84-92. PMID: 29132239
  6. Cheah AE, Yao J. Hand Fractures: Indications, the Tried and True and New Innovations.J Hand Surg Am 2016;41:712-22. PMID: 27113910
  7. Nesbitt KS, Failla JM, Les C. Assessment of instability factors in adult distal radius fractures. J Hand Surg Am 2004;29:1128-38.PMID: 15576227
  8. Walenkamp MM, Vos LM, Strackee SD, Goslings JC, Schep NW. The Unstable Distal Radius Fracture-How Do We Define It? A Systematic Review. J Wrist Surg 2015;4:307-16. PMID: 26649263
  9. Siddiqui N, Sarkar S. Isolated dorsal dislocation of the lunate. Open Orthop J2012;6:531-4. PMID: 23248723
  10. Sato R, Hibino N, Hamada Y, Sairyo K. Ulnolunate Ligament Avulsion Fracture of the Lunate: A Case Report. J Wrist Surg2017;6(2):148-151. PMID: 28428917
  11. Teisen H, Hjarbaek J. Classification of fresh fractures of the lunate. J Hand Surg Br1988;13(4):458-62. PMID: 3249151
  12. Ketonis C, Dwyer J, Ilyas AM. Timing of Debridement and Infection Rates in Open Fractures of the Hand: A Systematic Review. Hand (N Y) 2017;12:119-26. PMID: 28344521
  13. Meals C, Meals R. Hand fractures: a review of current treatment strategies. J Hand Surg Am 2013;38:1021-31. PMID: 23618458
  14. Herzberg G. Acute Dorsal Trans-scaphoid Perilunate Dislocations: Open Reduction and Internal Fixation. Tech Hand Up Extrem Surg2000;4(1):2-13. PMID: 16609406
  15. Arango D, Tiedeken NC, Ayzenberg M, Raphael J. Open perilunate injury with lunate revascularization after complete ligamentous avulsion. J Surg Case Rep2014;2014(5). PMID: 24876511
  16. Day CS. Fractures of the Metacarpals and Phalanges. In: Green DP, ed. Green's Operative Hand Surgery. Seventh ed. Philadelphia: Elsevier; 2016, pp. 231-77.
  17. Weinstein LP, Hanel DP. Metacarpal fractures.J Hand Surg Am 2002; 2(4):168–180.
  18. Stanbury SJ, Elfar JC. Perilunate dislocation and perilunate fracture-dislocation. J Am Acad Orthop Surg2011;19(9):554-62.PMID: 21885701
  19. Herzberg G, Comtet JJ, Linscheid RL, et al. Perilunate dislocations and fracture-dislocations: a multicenter study. J Hand Surg Am1993;18(5):768-79. PMID: 8228045
  20. Virani SR, Wajekar S, Mohan H, Dahapute AA. A unique case of bilateral trans-scaphoid perilunate dislocation with dislocation of lunate into the forearm. J Clin Orthop Trauma2016;7(Suppl 1):110-114. PMID: 28018087
  21. Ryan JR. Fracture and dislocation about the carpal lunate. Ann Emerg Med1980;9(3):158-60. PMID: 7362108
  22. Mahjoub S, Dunet B, Thoreux P, Masquelet AC. Transverse translunate fracture-dislocation: A rare injury. Hand Surg Rehabil2016;35(3):220-224. PMID: 27740466
  23. Rawlings ID. The management of dislocations of the carpal lunate. Injury1981;12(4):319-30. PMID: 7263037
  24. Takase K, Yamamoto K. Unusual combined scaphoid and lunate fracture of the wrist: a case report. J Hand Surg Am2006;31(3):414-7. PMID: 16516735
  25. Kaewlai R, Avery LL, Asrani AV, et al. Multidetector CT of carpal injuries: anatomy, fractures, and fracture-dislocations. Radiographics2008;28(6):1771-84. PMID: 18936035
  26. Akane M, Tatebe M, Iyoda K, et al. Partial necrosis of the lunate after a translunate palmar perilunate fracture dislocation. Nagoya J Med Sci2014;76(1-2):211-6. PMID: 25130008
  27. Mayfield JK, Johnson RP, Kilcoyne RK. Carpal dislocations: pathomechanics and progressive perilunar instability. J Hand Surg Am1980;5(3):226-41. PMID: 7400560
  28. Cooney WP, Bussey R, Dobyns JH, Linscheid RL. Difficult wrist fractures. Perilunate fracture-dislocations of the wrist. Clin Orthop Relat Res1987;(214):136-47. PMID: 3791735
  29. Adkison JW, Chapman MW. Treatment of acute lunate and perilunate dislocations. Clin Orthop Relat Res1982;(164):199-207. PMID: 7067286
  30. Apergis E, Maris J, Theodoratos G, et al. Perilunate dislocations and fracture-dislocations. Closed and early open reduction compared in 28 cases. Acta Orthop Scand Suppl1997;275:55-9. PMID: 9385268
  31. Komurcu M, Kürklü M, Ozturan KE, et al. Early and delayed treatment of dorsal transscaphoid perilunate fracture-dislocations. J Orthop Trauma2008;22(8):535-40. PMID: 18758284
  32. Inoue G, Shionoya K. Late treatment of unreduced perilunate dislocations. J Hand Surg Br1999;24(2):221-5. PMID: 10372780
  33. Harrington P, Quinlan WB. Palmar lunate trans-scaphoid, trans-triquetral fracture-dislocation.J Hand Surg Br1999;24(4):493-6. PMID: 10473166
  34. Kim BS, Grieb G, Rhodius P, et al. Compound Dorsal Dislocation of Lunate with Trapezoid Fracture. Clin Pract2016;6(4):879. PMID: 28176971
  35. Papp S. Carpal bone fractures. Hand Clin2010;26(1):119-27. PMID: 20006250
  36. van Onselen EB, Karim RB, Hage JJ, Ritt MJ. Prevalence and distribution of hand fractures. J Hand Surg Br2003;28(5):491-5. PMID: 12954264
  37. Hove LM. Fractures of the hand. Distribution and relative incidence. Scand J Plast Reconstr Surg Hand Surg1993;27(4):317-9. PMID: 8159947
  38. Dobyns JH, Beckenbaugh RD, Bryan RS, et al. Fractures of the hand and wrist. In: Flynn JE, editor. Hand surgery. Third ed. Philadelphia: Lippincott Williams & Wilkins; 1982.
  39. Rhemrev SJ, Ootes D, Beeres FJ, et al. Current methods of diagnosis and treatment of scaphoid fractures. Int J Emerg Med2011;4:4. PMID: 21408000
  40. Hey HW, Chong AK, Murphy D. Prevalence of carpal fracture in Singapore. J Hand Surg Am2011;36(2):278-83. PMID: 21276891
  41. Larsen CF, Brøndum V, Skov O. Epidemiology of scaphoid fractures in Odense, Denmark. Acta Orthop Scand1992;63(2):216-8. PMID: 1590062
  42. Höcker K, Menschik A. Chip fractures of the triquetrum. Mechanism, classification and results. J Hand Surg Br1994;19(5):584-8. PMID: 7822914
  43. Garcia-Elias M.Dorsal fractures of the triquetrum-avulsion or compression fractures? J Hand Surg Am1987;12(2):266-8. PMID: 3559084
  44. Cetti R, Christensen SE, Reuther K. Fracture of the lunate bone. Hand 1982 ;14(1):80-4. PMID: 7061015
  45. Hulsopple C, Deluca J, Jonas C. Treatment of Acute Carpal Bone Fractures. Curr Sports Med Rep2017;16(5):330-335. PMID: 28902755
  46. Stanbury SJ, Elfar JC. Perilunate dislocation and perilunate fracture-dislocation. J Am Acad Orthop Surg2011;19(9):554-62.PMID: 21885701

Classics

  1. Boyd GI. Isolated Fracture of the Lunate Bone. Edinb Med J1933;40(8):385-389. PMID: 29647036
  2. Campbell RD Jr, Lance EM, Yeoh CB. LUNATE AND PERILUNAR DISLOCATIONS. J Bone Joint Surg Br1964;46:55-72. PMID: 14126238
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