High-yield overview

Second Most Common Carpal Fracture | Dorsal Chip Pattern | FOOSH Mechanism

14-20%Of all carpal fractures

Dorsal ChipMost common pattern

FOOSHTypical mechanism

ConservativeMost treatment non-operative

TRIQUETRAL FRACTURE TYPES

Type I

PatternDorsal chip/avulsion fracture

TreatmentCast immobilization 4-6 weeks

Type II

PatternBody fracture

TreatmentCast, ORIF if displaced

Type III

PatternVolar avulsion fracture

TreatmentAssess for perilunate injury

Critical Must-Knows

Second most common carpal fracture after scaphoid
Dorsal chip fractures are 93% of all triquetral fractures
Best seen on lateral radiograph - dorsal cortex avulsion
FOOSH with ulnar deviation is typical mechanism
Excellent prognosis with conservative treatment for most

Clinical Pearls

"
Always check lateral view - dorsal chip easily missed on PA
"
Hamate impaction on triquetrum causes dorsal chip
"
Body fractures may indicate perilunate spectrum injury
"
Most dorsal chip fractures heal uneventfully with casting

High-Yield Triquetral Fracture Exam Points

Second Most Common

Triquetral fractures are the second most common carpal fracture (14-20%), after scaphoid fractures. The dorsal chip pattern is by far the most frequent, accounting for over 90% of cases.

Lateral View Essential

Dorsal chip fractures are often missed on PA radiographs. The lateral view is essential - look for a small osseous fragment dorsal to the triquetrum. This is a common exam presentation.

Mechanism of Injury

Two mechanisms cause dorsal chips: 1) Hamate impaction - ulnar deviation drives hamate into triquetrum, avulsing dorsal cortex; 2) Ligament avulsion - strong radiotriquetral or lunotriquetral ligament pulls off bone.

Perilunate Association

Body fractures (not chips) may indicate greater arc perilunate injury. Always assess for carpal malalignment and associated injuries when body fracture is present.

At a Glance: Triquetral Fracture Management

Fracture Type	Frequency	Management	Key Consideration
Type I - Dorsal chip	Over 90%	Cast 4-6 weeks	Excellent prognosis, most common type
Type II - Body fracture	Under 10%	Cast, ORIF if displaced	Assess for perilunate injury
Type III - Volar avulsion	Rare	Address associated injury	Part of perilunate spectrum
Comminuted body	Very rare	Complex reconstruction	High energy, poor prognosis

Mnemonic

TRIQ - TTRIQ - Triquetral Fracture Features

T	Type: mostly dorsal chip Over 90% are dorsal avulsion fractures
R	Radiograph lateral Lateral view essential - missed on PA
I	Impaction mechanism Hamate impacts triquetrum with ulnar deviation
Q	Quick healing 4-6 weeks casting, excellent prognosis

T	Type: mostly dorsal chip Over 90% are dorsal avulsion fractures	I	Impaction mechanism Hamate impacts triquetrum with ulnar deviation
R	Radiograph lateral Lateral view essential - missed on PA	Q	Quick healing 4-6 weeks casting, excellent prognosis

Hook:TRIQ - dorsal chip fractures heal Quickly with conservative treatment

Mnemonic

CHIP - DCHIP - Dorsal Chip Features

C	Common fracture Second most common carpal injury
H	Hamate impaction Ulnar deviation drives hamate into triquetrum
I	Immobilize in cast Short arm cast for 4-6 weeks
P	Prognosis excellent Most heal without complication

C	Common fracture Second most common carpal injury	I	Immobilize in cast Short arm cast for 4-6 weeks
H	Hamate impaction Ulnar deviation drives hamate into triquetrum	P	Prognosis excellent Most heal without complication

Hook:CHIP fractures have excellent Prognosis with simple Immobilization

Mnemonic

BODY - BBODY - Body Fracture Red Flags

B	Beware perilunate Body fractures may indicate greater arc injury
O	Overt displacement Displaced fractures need ORIF
D	Dedicated CT scan CT for surgical planning
Y	Yield to surgery Displaced body fractures require fixation

B	Beware perilunate Body fractures may indicate greater arc injury	D	Dedicated CT scan CT for surgical planning
O	Overt displacement Displaced fractures need ORIF	Y	Yield to surgery Displaced body fractures require fixation

Hook:BODY fractures Beware - may indicate perilunate injury

Mnemonic

LOOKLateral View Findings

L	Lateral X-ray best AP misses dorsal chip
O	Over lunate Fragment sits dorsal to lunate
O	Often small Easy to miss if not looking
K	Keep checking Gilula arcs Rule out perilunate

L	Lateral X-ray best AP misses dorsal chip	O	Often small Easy to miss if not looking
O	Over lunate Fragment sits dorsal to lunate	K	Keep checking Gilula arcs Rule out perilunate

Hook:LOOK at the lateral view - essential for dorsal chip fractures!

Overview and Epidemiology

Definition

Triquetral fractures are fractures of the triquetral (triquetrum) carpal bone, located on the ulnar side of the proximal carpal row. The most common pattern is a dorsal cortical avulsion (chip fracture), though body fractures also occur.

Epidemiology

Incidence: Second most common carpal fracture (14-20% of all carpal fractures)
First: Scaphoid fractures (70-80%)
Age distribution: Young to middle-aged adults
Gender: Male predominance
Mechanism: Usually FOOSH with ulnar deviation

Fracture Patterns

Dorsal Chip Fractures (Over 90%)

Small cortical avulsion from dorsal surface
Usually under 5mm in size
Best seen on lateral radiograph
Excellent prognosis with conservative treatment

Body Fractures (Under 10%)

Through substance of triquetrum
May be associated with perilunate injuries
Higher energy mechanism
May require surgical treatment

Volar Avulsion (Rare)

Usually associated with perilunate dislocation
Part of greater arc injury pattern
Requires assessment for carpal instability

Understanding triquetral anatomy and fracture patterns is essential for diagnosis and management.

Anatomy/Biomechanics

Osseous Anatomy

Shape and Configuration

Pyramidal shape: Triangular when viewed from ulnar aspect
Largest bone: Of the proximal carpal row by volume
Dorsal surface: Site of most common fracture pattern
Volar surface: Pisiform articulation

Articular Surfaces

Lunate (medial): Part of intercalated segment
Hamate (distal): Articulates with proximal hamate pole
Pisiform (volar): Small sesamoid articulation
TFCC (proximal): Through ulnocarpal complex

Surface Features

Dorsal ridge: Site of ligament attachments
Volar groove: Pisiform articulates here
Hamate facet: Distal articular surface

Blood Supply

Vascular Pattern

Multiple dorsal and volar nutrient vessels
No single dominant vessel (unlike lunate)
Lower risk of AVN than other carpals
Reliable healing potential

Vessel Entry Points

Dorsal surface: Primary blood supply
Volar surface: Secondary vessels
Non-articular surfaces: Additional supply

Biomechanics

Carpal Kinematics

Part of proximal row "intercalated segment"
Moves with scaphoid and lunate as functional unit
Limited independent motion
Ulnar border of proximal row

Load Transmission

Transmits force from ulnar carpus
Less load than radial side
Pisiform modifies force transmission
Hamate contact with ulnar deviation

Mechanism of Dorsal Chip

Two mechanisms produce dorsal chip fractures:

Hamate Impaction (Primary)

Wrist falls into extension and ulnar deviation
Hamate dorsal pole impacts triquetral dorsum
Shearing force avulses dorsal cortex

Ligamentous Avulsion

Strong radiotriquetral ligament pulls off bone
Lunotriquetral ligament may contribute
Traction injury rather than impaction

Both mechanisms produce similar fracture patterns.

Classification Systems

Anatomical Classification

The most practical classification based on fracture location:

Type I - Dorsal Cortical Fracture (Chip)

Over 90% of all triquetral fractures
Small dorsal cortical avulsion
Usually under 5mm fragment
Excellent prognosis
Treatment: Cast immobilization 4-6 weeks

Type II - Body Fracture

Through the body of triquetrum
Less than 10% of fractures
May indicate higher energy injury
Assess for associated injuries
Treatment: Cast if undisplaced, ORIF if displaced

Type III - Volar Avulsion

Rare isolated injury
Usually part of perilunate spectrum
Ligamentous origin (pisotriquetral, ulnotriquetral)
Treatment: Address associated carpal injury

Type IV - Comminuted Body

High-energy mechanism
Significant fragment displacement
Poor soft tissue envelope
Treatment: Complex reconstruction, may need external fixation

This classification guides treatment selection and prognosis.

Classification Summary

Type	Location	Frequency	Stability
Type I	Dorsal cortex	Over 90%	Stable
Type II	Body	Under 10%	Variable
Type III	Volar cortex	Rare	Usually part of perilunate
Type IV	Comminuted	Very rare	Unstable

Classification determines treatment approach and expected outcome.

Clinical Assessment

History

Mechanism of Injury

FOOSH: Fall onto outstretched hand with ulnar deviation
Direct blow: Rare, usually dorsum of wrist
Sports injury: Contact sports, ball sports
Motor vehicle accident: Dashboard injury

Key History Points

Exact mechanism and position of wrist
Energy of injury (height of fall, impact speed)
Immediate symptoms and swelling pattern
Prior wrist injuries or symptoms
Hand dominance and occupational demands

Physical Examination

Inspection

Swelling over ulnar wrist
May be subtle with dorsal chip fractures
Compare to contralateral side
Assess for skin integrity

Palpation

Triquetral tenderness: Over dorsal ulnar wrist
Anatomic snuffbox: Negative (rules out scaphoid)
DRUJ: Assess for associated injury
Pisiform: May have concomitant tenderness

Range of Motion

Limited by pain in acute setting
Ulnar deviation particularly painful
Assess forearm rotation (DRUJ involvement)

Neurovascular Assessment

Usually preserved
Check ulnar nerve function
Document baseline for comparison

Special Tests

Watson Test (Scaphoid Shift)

Should be negative
If positive, consider additional carpal injury

Ballottement Test

Lunotriquetral stability assessment
Compare to contralateral side
Positive = LT instability

Triquetral Shear Test

Direct pressure on triquetrum
Pain suggests triquetral pathology
Specific for triquetral injury

ECU Subluxation Test

Assess extensor carpi ulnaris
May have associated injury
Supinate and ulnar deviate wrist

Clinical examination guides imaging and treatment decisions.

Differential Diagnosis

Ulnar-sided wrist pain after a fall has a broad differential. The triquetral fracture must be distinguished from the conditions below, several of which can coexist with it.

Differential Diagnosis of Acute Ulnar-Sided Wrist Pain

Condition	Distinguishing feature	Key investigation
Triquetral dorsal chip fracture	Point tenderness dorsal-ulnar; dorsal fragment on lateral film	Lateral radiograph (CT if occult)
Ulnar styloid fracture	Tenderness at styloid tip; often with distal radius fracture	PA radiograph
TFCC tear	DRUJ pain, positive fovea sign, painful forearm rotation	MRI / wrist arthroscopy
Lunotriquetral ligament injury	Positive ballottement test, LT interval changes	MRI, dynamic imaging
Pisiform fracture	Tenderness over pisiform, pain on pisotriquetral grind	Carpal tunnel / 30-degree supinated view
Hook of hamate fracture	Hypothenar pain, tenderness over hook, ulnar nerve symptoms	Carpal tunnel view / CT
Perilunate / greater arc injury	Carpal malalignment, disrupted Gilula arcs, DISI/VISI	PA and lateral radiographs, CT

Clinical examination guides imaging and treatment decisions.

Investigations

Plain Radiographs

Standard Views

PA view: May miss dorsal chip fractures
Lateral view: Essential - shows dorsal fragment
Oblique views: Additional perspective

Lateral View (Critical)

The lateral radiograph is essential for dorsal chip diagnosis:

Small osseous fragment dorsal to carpal silhouette
Usually located at level of triquetrum
May be overlooked if not specifically sought
Best identified with true lateral positioning

PA View Findings

Body fractures may be visible
Carpal alignment assessment
Scapholunate and lunotriquetral intervals
Often normal with isolated dorsal chip

Signs of Associated Injury

Scapholunate widening (SL injury)
LT overlap or widening
Carpal arc disruption
DISI or VISI pattern on lateral

CT Scanning

Indications

Suspected body fracture not clear on X-ray
Surgical planning for displaced fractures
Assessment of comminution
Evaluation for perilunate injury

Key CT Findings

Fracture line orientation
Fragment size and displacement
Articular involvement
Associated carpal injuries

MRI

Indications

Suspected ligamentous injury
Occult fracture not seen on X-ray/CT
LT ligament assessment
TFCC evaluation

Findings

Bone marrow edema in fracture
Ligament integrity assessment
Associated soft tissue injury

Bone Scan

Limited Role

Rarely needed
May detect occult fracture
Superseded by MRI for most indications

Investigations are summarized below.

Imaging Strategy for Triquetral Fractures

Modality	Primary Role	Key Advantage	Limitation
Lateral X-ray	Dorsal chip diagnosis	Quick, essential view	May miss body fractures
PA X-ray	Body fracture, alignment	Carpal assessment	Misses dorsal chips
CT scan	Surgical planning	Fracture detail	Radiation, cost
MRI	Ligament assessment	Soft tissue detail	Cost, availability

The lateral radiograph is the most important view for dorsal chip diagnosis.

Management Algorithm

Conservative Management

Indications

All dorsal chip fractures (Type I)
Undisplaced body fractures (Type II)
No carpal instability
Elderly or low-demand patients

Protocol for Dorsal Chip Fractures

Immobilization

Short arm cast or splint
Wrist in neutral position
Duration: 4-6 weeks
May use removable splint for compliant patients

Follow-Up

Week 2: Clinical review, comfort check
Week 4-6: Assess tenderness, repeat X-ray
Week 6: If non-tender, begin mobilization

Expected Outcomes

Excellent prognosis for dorsal chip fractures
Union in 4-6 weeks
Full function typically restored
Rare persistent symptoms

Symptomatic Non-Union

Occurs in minority of cases
Persistent dorsal wrist pain
May require fragment excision
Generally straightforward procedure

Conservative management is successful for the vast majority of triquetral fractures.

Most triquetral fractures are managed conservatively with excellent results.

Surgical Technique

Fragment Excision for Symptomatic Non-Union

Indications

Symptomatic dorsal chip non-union
Persistent pain after 3-6 months of conservative treatment
Confirmed by imaging as source of symptoms

Patient Positioning

Supine with arm table
Tourniquet on upper arm
Wrist pronated for dorsal access

Surgical Technique

Incision

Small longitudinal incision (2-3 cm)
Over dorsal ulnar wrist
Centered on palpable fragment if detectable

Exposure

Incise extensor retinaculum between EDM and ECU
Retract tendons appropriately
Identify dorsal chip fragment in capsule
Usually embedded in dorsal ligament complex

Excision

Carefully isolate fragment
Excise completely with curette or rongeur
Preserve as much ligament as possible
Debride any fibrous tissue
Check for additional fragments

Closure

Repair retinaculum loosely
Standard skin closure
Soft dressing and splint

Postoperative Care

Splint 1-2 weeks
Early ROM exercises
Full activity 4-6 weeks

Fragment excision is a straightforward procedure with excellent outcomes.

Surgical intervention is rarely needed but provides reliable outcomes when indicated.

Complications

Complications of Dorsal Chip Fractures

Symptomatic Non-Union

Most common complication
Occurs in 5-10% of dorsal chips
Persistent dorsal wrist pain
Treatment: Fragment excision with good results

Extensor Tendon Irritation

Fragment may abrade overlying tendons
EDC or EDM most commonly affected
Presents as tendon pain or snapping
Treatment: Fragment excision

Dorsal Wrist Impingement

Large fragment blocks extension
Mechanical symptoms with wrist motion
Treatment: Surgical excision

Complications of Body Fractures

Malunion

Rare with appropriate treatment
May alter carpal kinematics
Can lead to secondary arthritis

Nonunion

More common than with dorsal chips
May require bone grafting
Associated with inadequate immobilization

Post-Traumatic Arthritis

Uncommon with isolated triquetral fractures
More common with associated injuries
May require salvage procedures

Lunotriquetral Instability

Can develop after body fractures
LT ligament may be injured at time of fracture
Presents with ulnar wrist pain and clicking
Treatment: LT repair or fusion

Complications of Surgical Treatment

Wound Complications

Infection (rare)
Dehiscence
Scar sensitivity

Hardware Issues

Screw prominence
K-wire migration
May require removal

Tendon Injury

ECU or EDM at risk
Usually prevented with careful technique
Repair if identified intraoperatively

Complication Summary

Complication	Frequency	Prevention	Management
Symptomatic non-union	5-10% of chips	Adequate immobilization	Fragment excision
Tendon irritation	Rare	Complete excision	Remove fragment
LT instability	Rare with body Fx	Recognize at injury	Ligament repair/fusion
Arthritis	Rare	Anatomic reduction	Activity modification to fusion

Complications are uncommon, and outcomes are generally excellent.

Postoperative Care

Conservative Treatment Protocol

Immobilization Phase (0-6 Weeks)

Week 0-2

Short arm cast or thermoplastic splint
Wrist neutral position
Immediate finger motion
Elevate to reduce swelling

Week 2-4

Continue immobilization
May switch to removable splint if compliant
Begin gentle finger exercises if not already

Week 4-6

Clinical review
Assess tenderness over triquetrum
Radiograph to confirm position
If non-tender, may discontinue splint

Rehabilitation Phase (6-12 Weeks)

Week 6-8

Begin active wrist ROM
Avoid resisted activities
Progress as tolerated

Week 8-12

Progressive strengthening
Return to normal activities
Sport-specific training if applicable

Surgical Treatment Protocol

Immediate Postoperative (0-2 Weeks)

Volar splint
Wound care
Finger motion
Elevation

Early Mobility (2-6 Weeks)

Removable splint
Gentle wrist ROM
Avoid loading
Suture removal at 10-14 days

Progressive Loading (6-12 Weeks)

Discontinue splint
Progressive strengthening
K-wire removal at 6 weeks if applicable
Return to activities 8-12 weeks

Follow-Up Schedule

Timepoint	Conservative	Surgical
Week 2	Comfort check	Wound check
Week 6	X-ray, assess healing	X-ray, ROM
Week 12	Final if healed	Final if healed
As needed	Symptomatic review	Hardware concerns

Most patients achieve full recovery with straightforward rehabilitation.

Outcomes and Prognosis

Dorsal Chip Fractures

Healing Rate

Over 95% heal with conservative treatment
Union typically at 4-6 weeks
Fibrous union may be asymptomatic

Functional Outcomes

Excellent ROM recovery (95-100% of normal)
Full grip strength return
Return to previous activity level
High patient satisfaction

Symptomatic Non-Union Rate

5-10% develop symptoms
Persistent dorsal wrist pain
Easily treated with excision
Excellent results after excision

Body Fractures

Healing Rate

Good healing with appropriate treatment
Union at 6-8 weeks typical
Higher nonunion rate if inadequately treated

Functional Outcomes

Good outcomes with anatomic reduction
May have some residual stiffness
Depends on associated injuries
Return to previous activity in most

Associated Injury Impact

Perilunate spectrum injuries have worse prognosis
LT instability may persist
May require additional procedures

Prognostic Factors

Favorable Factors

Dorsal chip pattern
Isolated injury
Early treatment
Compliant patient

Unfavorable Factors

Body fracture with displacement
Associated perilunate injury
Delayed diagnosis
High-energy mechanism

Return to Activity

Conservative Treatment

Sedentary work: 1-2 weeks with splint
Light manual: 6-8 weeks
Heavy manual: 8-12 weeks
Contact sports: 8-12 weeks

Surgical Treatment

Similar timelines
May be slightly longer for body ORIF
Athlete return at 3-4 months

The prognosis for triquetral fractures is excellent overall.

Evidence Base

Level IV

Zander MEL et al. Carpal fractures: epidemiology, classification and treatment of 6542 fractures from the Swedish Fracture Registry

Key Findings:

Population registry of 6542 carpal fractures: scaphoid 60%, triquetrum 25%, hamate 5%, trapezium 4%
Triquetrum is the second most commonly fractured carpal bone
Mean age at injury 41 years; 69% of patients male
Carpal fractures had only a small negative effect on hand function and EQ-5D at one year

Clinical Implication: The largest population-based registry confirms the triquetrum as the second most common carpal fracture and the male, young-adult demographic, anchoring epidemiology in registry-grade data rather than single-centre series.

Source: J Hand Surg Eur Vol 2023

Verify on PubMed (PMID 37747716)

Level IV

Höcker K, Menschik A. Chip fractures of the triquetrum. Mechanism, classification and results

Key Findings:

Series of 231 triquetral fractures with 65 followed for a mean of 47 months
Dorsal chip caused by the chisel action of the dorso-proximal hamate against the extended, ulnar-deviated wrist
Conservative immobilisation for 3 weeks was successful; fragment union when it occurred took 6 to 8 weeks
No post-traumatic carpal instability and no avascular necrosis observed; all body fractures united

Clinical Implication: This defining mechanistic series supports short-duration cast immobilisation and reassures that avascular necrosis and instability are not expected after isolated triquetral fractures.

Source: J Hand Surg Br 1994

Verify on PubMed (PMID 7822914)

Level IV

Levy M, Fischel RE, Stern GM, Goldberg I. Chip fractures of the os triquetrum: the mechanism of injury

Key Findings:

Cadaveric and radiographic study disproving the avulsion-only theory of dorsal chip fractures
Mechanism is a chisel action of the ulnar styloid on the dorsum of the triquetrum
A forceful fall in dorsiflexion and ulnar deviation can also fracture the triquetral body
A prolonged ulnar styloid projecting beyond the ulnar head was consistently noted

Clinical Implication: Recognising the impaction (rather than purely avulsion) mechanism explains why isolated dorsal chips are typically stable and why higher-energy loading can extend into the body.

Source: J Bone Joint Surg Br 1979

Verify on PubMed (PMID 479259)

Level III

Welling RD et al. MDCT and radiography of wrist fractures: radiographic sensitivity and fracture patterns

Key Findings:

Prospective comparison of radiography with CT as the gold standard in 61 wrist examinations
Only 20% of triquetral fractures were detected prospectively on radiographs
30% of all wrist fractures were not diagnosed prospectively on plain films
CT should be considered after a negative radiograph when clinical suspicion persists

Clinical Implication: Plain radiographs miss the majority of triquetral fractures; persistent ulnar-sided tenderness with normal films warrants dedicated views or CT rather than reassurance.

Source: AJR Am J Roentgenol 2008

Verify on PubMed (PMID 18094287)

Level IV

Boeddrich O et al. Epidemiology of carpal fractures: is it only about the scaphoid?

Key Findings:

Retrospective series of 178 emergency carpal fractures over 6 years
The triquetrum was the most frequently affected bone, ahead of the scaphoid in this cohort
Almost all triquetral fractures were treated conservatively
Young men carried the highest risk of carpal fracture and CT was usually required

Clinical Implication: Emergency-department data reinforce that the overwhelming majority of triquetral fractures are managed non-operatively, with surgery reserved for perilunate injury patterns.

Source: Eur J Trauma Emerg Surg 2023

Verify on PubMed (PMID 36650282)

The evidence supports conservative management for most triquetral fractures with excellent expected outcomes.

Viva Scenarios

Clinical Decision Scenarios

Use these scenarios to practise clinical reasoning and management decisions

CLINICAL SCENARIOStandard

Missed Triquetral Fracture

CLINICAL PROMPT

"A 25-year-old man presents 2 weeks after a fall onto his hand. He has ongoing ulnar wrist pain. PA radiograph was reported as normal. How do you evaluate this patient?"

PRACTICAL APPROACH

This is a common scenario where a triquetral fracture may have been missed on initial imaging. **Clinical Assessment:** I would take a detailed history of the mechanism - a fall onto an outstretched hand with ulnar deviation is the typical mechanism for triquetral fracture. I would examine for point tenderness over the triquetrum on the dorsal ulnar wrist, and perform a ballottement test to assess lunotriquetral stability. **Imaging Review:** The key issue here is that dorsal chip fractures of the triquetrum are frequently missed on PA radiographs. I would specifically request and review a lateral wrist radiograph. On the lateral view, I would look for a small osseous fragment dorsal to the carpus, at the level of the triquetrum. This is the characteristic appearance of a dorsal chip fracture. **Diagnosis:** If the lateral view confirms a dorsal chip fracture, this explains the ongoing symptoms. Dorsal chips are the most common pattern (over 90%) and are second only to scaphoid fractures in carpal fracture frequency. **Management:** For a dorsal chip fracture diagnosed at 2 weeks, I would recommend short arm cast immobilization for an additional 4 weeks (total 6 weeks from injury). The prognosis is excellent, with over 95% healing with conservative treatment. **Follow-Up:** I would review at 6 weeks. If still tender, I would continue immobilization and arrange follow-up imaging. If non-tender, mobilization can begin. I would counsel the patient that 5-10% develop symptomatic non-union, which can be effectively treated with fragment excision if needed.

KEY CLINICAL POINTS

Lateral view is essential - chips missed on PA

Second most common carpal fracture

Dorsal chip over 90% of triquetral fractures

Excellent prognosis with conservative treatment

COMMON PITFALLS

Not obtaining or reviewing lateral radiograph

Assuming normal PA means no fracture

Missing associated carpal injuries

FURTHER QUESTIONS

"How long would you immobilize this patient?"

"What would you do if there is persistent pain at 6 weeks?"

"How do you counsel about the risk of non-union?"

CLINICAL SCENARIOChallenging

Triquetral Body Fracture Assessment

CLINICAL PROMPT

"A 30-year-old motorcyclist presents after a crash. X-rays show a displaced triquetral body fracture. How do you approach this injury?"

PRACTICAL APPROACH

A triquetral body fracture from a high-energy mechanism requires careful assessment for associated injuries. **Initial Assessment:** First, I would ensure this patient has been assessed for other injuries given the mechanism. Motorcyclists commonly have multiple injuries. I would complete the trauma workup before focusing on the wrist. **Radiographic Analysis:** For the wrist specifically, I would carefully assess the radiographs for: - Carpal alignment on the PA view - looking for scapholunate or lunotriquetral widening - Gilula's arcs - any disruption suggests ligamentous injury - Lateral view - assessing for DISI or VISI pattern Triquetral body fractures may be part of a greater arc perilunate injury pattern, so I need to exclude this. **Advanced Imaging:** I would obtain a CT scan to characterize the fracture pattern, assess displacement, and evaluate for additional carpal injuries. If there is any concern for ligamentous injury, MRI would be helpful. **Classification:** This is a Type II triquetral fracture (body fracture). With displacement, it requires surgical fixation to restore anatomy and carpal stability. **Surgical Planning:** If the fracture is isolated and displaced, I would plan for ORIF through a dorsal approach. I would reduce the fracture anatomically and fix with a headless compression screw if bone stock permits, or K-wires for smaller fragments. **Associated Injuries:** If imaging reveals perilunate instability, I would address the entire carpal injury - typically with open reduction, ligament repair, and stabilization of the carpal bones. **Postoperative Care:** Splinting for 2 weeks, then protected ROM. K-wire removal at 6 weeks if used. Full activity at 3 months.

KEY CLINICAL POINTS

High-energy mechanism - assess for polytrauma

Body fractures may indicate perilunate injury

CT for surgical planning

ORIF for displaced body fractures

COMMON PITFALLS

Not assessing for perilunate instability

Treating as isolated injury without full evaluation

Using conservative treatment for displaced body fracture

FURTHER QUESTIONS

"What would you do if imaging reveals lunotriquetral widening?"

"What are the fixation options for body fractures?"

"How do you approach a perilunate injury pattern?"

CLINICAL SCENARIOStandard

Symptomatic Triquetral Non-Union

CLINICAL PROMPT

"A patient returns 6 months after a triquetral dorsal chip fracture, still complaining of dorsal wrist pain with gripping. Radiographs confirm non-union. How do you manage this?"

PRACTICAL APPROACH

This patient has developed symptomatic non-union of a triquetral dorsal chip fracture, which occurs in approximately 5-10% of cases. **Clinical Assessment:** I would confirm that the symptoms correlate with the fracture location by examining for point tenderness directly over the dorsal triquetrum. I would also assess for extensor tendon irritation, as the fragment may abrade the overlying EDM or EDC tendons. **Imaging:** The radiographs confirm the non-union. I would look at the fragment size and position. If there is any concern about body involvement or additional pathology, CT or MRI would be helpful, but is not usually necessary for a straightforward dorsal chip non-union. **Treatment Options:** The standard treatment for symptomatic dorsal chip non-union is surgical excision. This is a straightforward procedure with excellent outcomes. **Surgical Technique:** Through a small dorsal incision between the 4th and 5th extensor compartments, I would: 1. Incise the retinaculum, protecting EDM and ECU 2. Identify the fragment within the dorsal capsule 3. Excise the fragment completely 4. Debride any fibrous tissue 5. Close the retinaculum loosely **Postoperative Care:** - Soft dressing and splint for 1-2 weeks - Begin ROM immediately after splint removal - Return to full activity at 4-6 weeks **Expected Outcome:** Fragment excision for symptomatic non-union has excellent results. Over 95% of patients have complete pain relief and return to full function. I would counsel the patient that this is a reliable procedure with low complication risk and predictably good outcomes.

KEY CLINICAL POINTS

Symptomatic non-union in 5-10% of dorsal chips

Fragment excision is treatment of choice

Simple procedure with excellent outcomes

Quick recovery and return to function

COMMON PITFALLS

Continuing prolonged conservative treatment for symptomatic non-union

Not confirming symptoms correlate with fragment

Missing extensor tendon involvement

FURTHER QUESTIONS

"Can you describe the surgical approach for fragment excision?"

"What is the expected recovery timeline?"

"How would you manage an associated tendon injury?"

MCQ Practice Points

Fracture Frequency

Q: What is the second most common carpal fracture? A: Triquetral fractures are the second most common carpal fracture (14-20%), after scaphoid fractures which account for 70-80% of all carpal fractures.

Fracture Pattern

Q: What percentage of triquetral fractures are dorsal chip fractures? A: Over 90% of triquetral fractures are dorsal chip (cortical avulsion) fractures. Body fractures account for less than 10%.

Radiographic Diagnosis

Q: Which radiographic view is most important for diagnosing triquetral dorsal chip fractures? A: The lateral radiograph is essential. Dorsal chip fractures are frequently missed on PA views but clearly visible as a small osseous fragment dorsal to the carpus on the lateral.

Mechanism of Injury

Q: What is the primary mechanism causing triquetral dorsal chip fractures? A: Hamate impaction - when the wrist falls into extension and ulnar deviation, the hamate dorsal pole impacts the triquetral dorsum, avulsing a fragment of dorsal cortex.

Treatment Approach

Q: What is the standard treatment for an isolated triquetral dorsal chip fracture? A: Conservative management with short arm cast for 4-6 weeks. Over 95% heal with immobilization, and the prognosis is excellent.

Non-Union Management

Q: How should symptomatic non-union of a triquetral dorsal chip be treated? A: Surgical fragment excision through a dorsal approach. This is a straightforward procedure with excellent outcomes in over 95% of patients.

Understanding these key concepts will help with exam success.

Guidelines, Registries & Global Practice

Global Epidemiology (Registry & Population Evidence)

There is no dedicated triquetral-fracture trial registry; the strongest evidence comes from national fracture registries and large carpal-fracture series that report relative frequency, demographics and treatment patterns.

Population & Registry Evidence on Triquetral Fractures

Source (region)	Cohort	Key finding	Evidence
Swedish Fracture Registry (Sweden)	6542 carpal fractures	Triquetrum 25% of carpal fractures (2nd after scaphoid 60%); mean age 41, 69% male	Level IV registry
Boeddrich, Germany	178 ED carpal fractures	Triquetrum most frequent in cohort; almost all treated conservatively	Level IV
Höcker, Austria	231 triquetral fractures	Dorsal chip predominates; 3-week immobilisation successful; no AVN/instability	Level IV
Welling, USA (CT vs XR)	61 wrist examinations	Only 20% of triquetral fractures seen on radiographs; 30% of wrist fractures occult	Level III

Registry and cohort data are consistent across Europe and North America: the triquetrum is the second most commonly fractured carpal bone, the dorsal cortical (chip) pattern predominates, and the population is skewed towards young adult men. Plain radiographs substantially under-detect these fractures, so persistent clinical suspicion should drive further imaging.

Guideline & Society Positions

No single national society publishes a stand-alone triquetral-fracture guideline; management is governed by general carpal-fracture and wrist-trauma principles. The table below summarises where authoritative guidance is drawn from across major bodies.

Society & Guideline Guidance (Carpal/Wrist Trauma)

Body (region)	Position relevant to triquetral fracture	Evidence basis
AAOS (USA)	Carpal fractures other than scaphoid managed by general fracture principles; CT for occult or displaced injury	Expert consensus
BOA / BSSH (UK)	Wrist-trauma standards emphasise excluding perilunate injury and dedicated views when radiographs are normal but tenderness persists	Consensus standards
AO Foundation (global)	Isolated stable triquetral fractures: cast immobilisation; ORIF reserved for displaced body fractures and perilunate patterns	Expert consensus
EFORT / NICE (Europe, UK)	No specific triquetral guidance; cross-sectional imaging recommended where plain films are non-diagnostic and suspicion remains	Consensus / NG38 fracture principles

Practice Variation & Australian Context

Consistent across systems: conservative management (short-arm cast or splint, typically 3 to 6 weeks) is standard worldwide for isolated dorsal chip and undisplaced body fractures, reflecting Level IV evidence of reliable union without instability or avascular necrosis.
Variation: immobilisation duration varies (3 weeks in the Höcker series versus the more commonly quoted 4 to 6 weeks); thresholds for CT after a normal radiograph differ by access and local protocol.
Surgery: reserved for displaced body fractures, perilunate spectrum injuries and symptomatic dorsal chip non-union (fragment excision) in all systems.
Australia: the fall-onto-outstretched-hand mechanism is common in sport and occupational settings; the orthopaedic community follows the same international evidence, with hand-surgery subspecialists managing perilunate and complex injuries and general orthopaedic surgeons performing fragment excision. Digital imaging and ready CT access aid detection of subtle dorsal chips, and the excellent prognosis means most patients, including those under workers compensation pathways, return to work within weeks.