High Yield Overview

TRAPEZIUM FRACTURES

Radial Distal Row | Body vs Ridge Pattern | CMC Joint Implications

3-5%Of all carpal fractures

RidgeMost common pattern

CMCJoint involvement critical

FCRRidge in FCR groove

TRAPEZIUM FRACTURE TYPES

Body Fracture

PatternThrough trapezium body

TreatmentORIF if displaced, CMC reduction

Ridge Fracture

PatternVolar ridge avulsion

TreatmentConservative, excision if symptomatic

Comminuted

PatternHigh-energy pattern

TreatmentComplex reconstruction, consider fusion

Critical Must-Knows

Two distinct patterns: Body fractures (articular) vs ridge fractures (extra-articular)
Body fractures involve thumb CMC joint - articular reduction critical
Ridge fractures are FCR insertion avulsions - usually conservative
Bennett's variant: Trapezium body fracture may resemble Bennett's mechanism
CT essential for body fracture surgical planning

Examiner's Pearls

"
Ridge fractures most common - in FCR groove, usually conservative
"
Body fractures involve CMC joint - need anatomic reduction
"
Carpal tunnel view shows ridge fractures best
"
High rate of FCR tendon irritation with ridge fractures

High-Yield Trapezium Fracture Exam Points

Two Distinct Patterns

Body fractures are intra-articular, involving the thumb CMC joint - require anatomic reduction. Ridge fractures are extra-articular avulsions in the FCR groove - usually heal with conservative treatment.

Carpal Tunnel View

The carpal tunnel (Roberts) view is essential for visualizing ridge fractures. Standard PA and lateral views may miss this pattern. Ask for this view specifically if ridge fracture is suspected.

CMC Joint Implications

Body fractures affect the thumb CMC joint - the most important joint for hand function. Malreduction leads to early arthritis. Consider these as similar in importance to Bennett's fractures.

FCR Tendon Association

The FCR tendon passes through the volar trapezial ridge groove. Ridge fractures can cause FCR tenosynovitis or rupture. Symptomatic non-union may require fragment excision.

At a Glance: Trapezium Fracture Management

Fracture Type	Location	Management	Key Consideration
Ridge fracture	Volar ridge (FCR groove)	Cast 4-6 weeks	Symptomatic non-union: excise
Body - undisplaced	Through body	Thumb spica cast 6 weeks	Monitor for displacement
Body - displaced	Through body	ORIF with screws/K-wires	CMC articular reduction critical
Vertical split	Sagittal through CMC	ORIF - restore CMC congruity	Similar to Bennett's
Comminuted	Entire trapezium	Complex reconstruction or fusion	High energy, poor prognosis

Mnemonic

TRAP - Trapezium Fracture Features

Two patterns

Body fractures vs ridge fractures

Ridge in FCR groove

Volar ridge avulsion, FCR tendon issues

Articular involvement

Body fractures involve CMC joint

Pronated (Roberts) view

Carpal tunnel view shows ridge best

Memory Hook:TRAP - Two patterns, Ridge in FCR groove, Articular body, Pronated view needed

Mnemonic

RIDGE - Ridge Fracture Management

Roberts view for diagnosis

Carpal tunnel view essential

Immobilize conservatively

Cast treatment usually successful

Delayed symptoms possible

FCR tenosynovitis may develop

Go to surgery for symptoms

Fragment excision if persistent pain

Excellent prognosis

Good outcomes with appropriate treatment

Memory Hook:RIDGE fractures: Roberts view, Immobilize, may need Delayed excision, Good prognosis

Mnemonic

BODY - Body Fracture Priorities

Base of thumb CMC

Articular involvement critical

ORIF if displaced

Anatomic reduction required

Don't miss displacement

CT for surgical planning

Yield to early arthritis

Malreduction causes CMC OA

Memory Hook:BODY fractures involve CMC joint - ORIF for Displaced patterns

Overview and Epidemiology

Definition

Trapezium fractures are fractures of the trapezium carpal bone, located on the radial side of the distal carpal row. They include body fractures (involving the thumb CMC articular surface) and ridge fractures (extra-articular avulsions of the volar ridge).

Epidemiology

Incidence: 3-5% of all carpal fractures
Ranking: Second most common distal row fracture (after hamate)
Age distribution: Young to middle-aged adults
Gender: Male predominance
Mechanism: Axial load through thumb or direct trauma

Fracture Patterns

Ridge Fractures (More Common)

Avulsion of volar trapezial ridge
FCR tendon attachment
Extra-articular
Usually conservative treatment

Body Fractures (Less Common but More Significant)

Through trapezium body
Involves CMC articular surface
Requires anatomic reduction
Higher complication rate

Clinical Significance

The trapezium's position makes it critical for thumb function:

Articulates with thumb metacarpal (CMC joint)
Allows opposition, flexion, extension, abduction
CMC joint is the most mobile and important thumb joint
Injury affects grip and pinch strength

Understanding the two distinct fracture patterns is essential for appropriate management.

Anatomy/Biomechanics

Osseous Anatomy

Shape and Configuration

Saddle-shaped: Allows multiplanar thumb motion
Volar ridge: Prominent projection on palmar surface
Body: Main bone mass with articular surfaces

Articular Surfaces

Distal (CMC): Saddle joint with 1st metacarpal
Medial: Articulates with trapezoid
Proximal: Articulates with scaphoid

Volar Ridge

Location: Palmar trapezium surface
FCR groove: Ridge forms radial border of groove
Attachments: Transverse carpal ligament, FCR sheath

Blood Supply

Vascular Pattern

Multiple small vessels
No single dominant vessel
Lower AVN risk than scaphoid or lunate
Good healing potential

Entry Points

Dorsal and volar surfaces
Non-articular areas
Adequate anastomoses

Biomechanics

CMC Joint Function

Saddle joint: Biaxial motion
Allows opposition, circumduction
Critical for grip and pinch
Most functionally important thumb joint

Load Transmission

Forces from thumb concentrate here
High stress during pinch and grip
Predisposed to arthritic changes

FCR Relationship

FCR passes through volar groove
Ridge fractures affect FCR glide
Chronic irritation causes tenosynovitis

FCR Tendon Vulnerability

The FCR tendon passes through a groove bounded by the volar ridge. Ridge fractures can cause FCR irritation, tenosynovitis, or even rupture. Always assess FCR function and consider this in management.

Understanding anatomy guides surgical approach and management priorities.

Classification Systems

Anatomical Classification

Based on fracture location:

Type I - Vertical Body Fracture

Sagittal split through body
Involves CMC articular surface
Similar mechanism to Bennett's fracture
Treatment: ORIF if displaced

Type II - Horizontal Body Fracture

Coronal split through body
May involve scaphotrapezial joint
Less common than vertical
Treatment: ORIF if displaced

Type III - Dorsal Ridge Fracture

Small dorsal avulsion
Ligament attachment site
Usually small fragment
Treatment: Conservative

Type IV - Volar Ridge Fracture

Most common pattern overall
FCR groove avulsion
Extra-articular
Treatment: Conservative, excision if symptomatic

Type V - Comminuted Body

Multiple fragments
High-energy mechanism
Articular involvement
Treatment: Complex reconstruction or fusion

Location and articular involvement guide treatment.

Classification Summary

Type	Location	Articular	Treatment
Ridge	Volar/dorsal ridge	No	Conservative, excision if needed
Vertical body	Sagittal through CMC	Yes	ORIF
Horizontal body	Coronal	Variable	ORIF if displaced
Comminuted	Entire body	Yes	Complex reconstruction/fusion

Classification determines treatment approach and expected outcomes.

Clinical Assessment

History

Mechanism of Injury

FOOSH: Fall with thumb abducted
Direct trauma: Blow to thenar eminence
Axial load: Punch or fall onto thumb
Avulsion: Forceful wrist flexion (ridge fractures)

Key History Points

Exact mechanism and thumb position
Energy of injury
Immediate symptoms
Hand dominance and occupation
Prior thumb/wrist pathology

Physical Examination

Inspection

Swelling over thenar eminence
Bruising at thumb base
Compare to contralateral hand

Palpation

Anatomic snuffbox: May be tender (overlaps with scaphoid)
Thenar eminence: Direct trapezium tenderness
Volar wrist crease: Ridge tenderness
FCR tendon: Assess for tenosynovitis

Range of Motion

Thumb CMC motion limited by pain
Opposition particularly affected
Compare to contralateral

Stability Assessment

CMC joint stability
Stress testing after adequate analgesia
Compare to opposite side

Neurovascular Assessment

Usually preserved
Median nerve (thenar branch) may be at risk
Document baseline

Special Tests

Grind Test

Axial load with rotation at CMC
Pain suggests CMC pathology
May be positive with both fracture and arthritis

FCR Provocation

Resisted wrist flexion
Pain suggests FCR involvement
Important for ridge fractures

Thumb Pinch Strength

Markedly reduced with trapezium injury
Compare to contralateral
Baseline for recovery assessment

Clinical examination helps differentiate ridge from body fractures.

Investigations

Plain Radiographs

Standard Views

PA view: May show body fractures
Lateral view: Assess displacement
Oblique view: Additional perspective

Carpal Tunnel (Roberts) View

Essential for ridge fractures
Wrist hyperextended, beam angled 25 degrees
Shows volar ridge clearly
Ridge fractures easily missed without this view

Betts View (Hyperpronation)

Isolates trapezium from overlapping bones
Good for body fracture assessment
Complement to carpal tunnel view

Signs to Look For

Ridge fragment on carpal tunnel view
Body fracture line on PA/oblique
CMC joint congruity
Associated thumb metacarpal injury

CT Scanning

Indications

Body fracture surgical planning
Assessment of CMC articular surface
Comminution evaluation
Occult fracture detection

Key CT Findings

Fracture orientation (vertical vs horizontal)
Articular step-off or gap
Fragment size and displacement
Associated injuries

MRI

Indications

Soft tissue assessment
FCR tendon evaluation
Occult fracture detection
Ligament injury assessment

Findings

Bone marrow edema
FCR tenosynovitis
Ligament integrity

Investigations summary is provided below.

Imaging Strategy for Trapezium Fractures

Modality	Primary Role	Advantage	Limitation
PA/Lateral X-ray	Body fractures	Available, quick	May miss ridge fractures
Carpal tunnel view	Ridge fractures	Essential for ridge	Specific technique needed
CT scan	Surgical planning	Articular detail	Essential for ORIF
MRI	Soft tissue, FCR	FCR tendon status	Rarely needed acutely

The carpal tunnel view is essential and must be specifically requested for ridge fracture evaluation.

Management Algorithm

Ridge Fracture Management

Initial Treatment

Ridge fractures are extra-articular and generally have excellent prognosis with conservative treatment.

Immobilization

Thumb spica splint or cast
Thumb in functional position
Duration: 4-6 weeks
May use removable splint if compliant

Follow-Up

Week 2: Clinical review
Week 4-6: Assess tenderness, mobility
If non-tender, begin mobilization

Symptomatic Non-Union

Occurs in minority of cases:

Presentation

Persistent thenar pain
FCR tenosynovitis symptoms
Pain with wrist flexion/extension
Tender over volar ridge

Management

Trial of splinting and anti-inflammatories
Steroid injection may provide temporary relief
Fragment excision if persistent symptoms

Excision Technique

Volar approach through FCR sheath
Excise fragment, smooth bed
Protect FCR tendon
Good outcomes expected

Ridge fractures have excellent prognosis with appropriate management.

Treatment depends on fracture type - ridge vs body.

Surgical Technique

ORIF for Trapezium Body Fracture

Preoperative Planning

CT scan for fracture characterization
Plan approach based on fracture pattern
Identify fragment size for fixation choice

Patient Setup

Supine, arm table
Tourniquet applied
Fluoroscopy available

Dorsal Approach

Skin Incision

Longitudinal over dorsal CMC joint
Start at 1st metacarpal base
Extend proximally 3-4 cm

Deep Dissection

Identify radial sensory nerve branches (protect)
Retract EPB and EPL appropriately
Incise CMC capsule longitudinally
Expose trapezium and articular surface

Fracture Reduction

Visualization

Direct view of articular surface
Assess fracture pattern
Identify all fragments

Reduction Technique

Use dental pick or small elevator
Manipulate fragments to anatomic position
Assess reduction visually and with fluoroscopy
Provisional K-wire fixation

Definitive Fixation

Screw Technique

2.0-2.4mm headless compression screw
Drill, measure, tap if needed
Insert screw perpendicular to fracture line
Countersink below cartilage
Check with fluoroscopy

K-Wire Technique

Multiple 1.1-1.25mm K-wires
Cross fracture in different planes
May span CMC joint if needed
Plan for removal at 6 weeks

Closure

Repair CMC capsule
Close subcutaneous layer
Skin closure
Thumb spica splint

Anatomic reduction of the CMC surface is essential for good outcomes.

Surgical technique varies based on fracture pattern.

Complications

Ridge Fracture Complications

FCR Tenosynovitis

Common with symptomatic non-union
Fragment irritates tendon
Treatment: Excision with debridement

FCR Rupture (Rare)

Chronic irritation from fragment
Usually in untreated symptomatic cases
Treatment: Fragment excision, tendon repair if possible

Symptomatic Non-Union

Occurs in 10-20% of ridge fractures
May be asymptomatic
Treatment: Excision if symptomatic

Body Fracture Complications

Malunion

CMC articular incongruity
Leads to early arthritis
Prevention: Anatomic reduction
Treatment: May need osteotomy or fusion

Post-Traumatic CMC Arthritis

Most significant long-term complication
Related to residual step-off
Progressive thumb base pain
Treatment: CMC arthroplasty or fusion

Nonunion

Uncommon with proper treatment
May require bone grafting
Consider internal fixation

Stiffness

CMC joint may become stiff
Prevention: Early mobilization when stable
Treatment: Hand therapy, patience

Surgical Complications

Radial Sensory Nerve Injury

Dorsal approach at risk
Prevention: Careful identification
Treatment: Usually recovers, may need neurolysis

Screw/Hardware Problems

Joint penetration
Prominent hardware
Treatment: Removal when healed

Infection

Rare
Standard treatment principles

Complication Summary

Complication	Fracture Type	Prevention	Management
FCR tenosynovitis	Ridge	Early treatment	Fragment excision
CMC arthritis	Body	Anatomic reduction	Arthroplasty or fusion
Non-union	Either	Adequate immobilization/fixation	Bone graft, fixation
Stiffness	Body	Early mobilization	Hand therapy

CMC arthritis is the main concern with body fractures; FCR problems with ridge fractures.

Postoperative Care

Conservative Treatment Protocol

Ridge Fractures

Week 0-4

Thumb spica splint or cast
Finger motion encouraged
Ice and elevation for swelling

Week 4-6

Assess tenderness
If non-tender, begin mobilization
Wean from splint

Week 6+

Progressive ROM and strengthening
Return to activities as tolerated
Monitor for late FCR symptoms

Undisplaced Body Fractures

Week 0-6

Thumb spica cast
Serial radiographs at week 2 and 4
Finger exercises throughout

Week 6-8

If healed, transition to splint
Begin gentle thumb ROM
Progressive activity

Surgical Treatment Protocol

ORIF for Body Fractures

Immediate (0-2 Weeks)

Thumb spica splint
Elevate and ice
Finger motion

Week 2-6

Thumb spica cast
Monitor wound
Continue finger ROM

Week 6

Radiographs to assess healing
K-wire removal if used
Transition to removable splint
Begin gentle thumb ROM

Week 6-12

Progressive ROM
Light strengthening
Hand therapy guidance

Week 12+

Full activities as tolerated
Progressive grip strengthening
Sport at 3-4 months

Ridge Excision

Week 0-2

Light splint for comfort
Suture removal at 10-14 days
Begin ROM

Week 2-6

Progressive activities
Usually fully recovered
Return to work/sport

Follow-Up Schedule

Treatment	Week 2	Week 6	Week 12	Month 6
Conservative ridge	Clinical	If symptomatic	As needed	-
Conservative body	X-ray	X-ray, ROM	Function	As needed
ORIF body	Wound	X-ray, K-wire removal	Function	Final
Ridge excision	Sutures	Final	-	-

Rehabilitation is tailored to fracture type and treatment method.

Outcomes and Prognosis

Ridge Fractures

Conservative Treatment Outcomes

Union rate: Over 90% heal with casting
Function: Excellent in most cases
Symptomatic non-union: 10-20%

After Fragment Excision

Pain relief: Over 95% satisfied
Function: Return to previous activities
FCR problems: Resolved with excision

Body Fractures

Conservative Treatment (Undisplaced)

Good outcomes when truly undisplaced
Risk of secondary displacement
Close monitoring essential

Surgical Treatment (ORIF)

Articular reduction determines outcome
Step-off under 1mm: Good outcomes
Step-off over 2mm: Higher arthritis rate
ROM recovery: 80-90% of contralateral

Long-Term CMC Joint Health

Anatomic reduction: Lower arthritis rate
Malreduction: Progressive CMC OA
May require later CMC arthroplasty

Prognostic Factors

Favorable

Ridge fracture pattern
Undisplaced body fracture
Early treatment
Anatomic reduction achieved
Compliant patient

Unfavorable

Displaced body fracture
Comminuted pattern
Delayed treatment
Articular incongruity
Associated injuries

Return to Activity

Ridge Fractures

Desk work: 2-4 weeks
Light manual: 4-6 weeks
Heavy manual: 6-8 weeks
Sports: 6-8 weeks

Body Fractures

Desk work: 4-6 weeks
Light manual: 8-12 weeks
Heavy manual: 12-16 weeks
Contact sports: 4-6 months

Prognosis depends on fracture type and treatment adequacy.

Evidence Base

Level IV

📚 Walker JL et al. Fractures of the Trapezium

Key Findings:

Two distinct patterns: ridge and body fractures
Ridge fractures most common pattern
Body fractures require anatomic reduction
Carpal tunnel view essential for ridge diagnosis

Clinical Implication: Classification into ridge vs body patterns guides treatment approach and prognosis.

Source: J Hand Surg Am 1988

Level IV

📚 Cordrey LJ, Ferrer-Torells M. Management of Fractures of the Greater Multangular

Key Findings:

Body fractures involve CMC articular surface
Anatomic reduction essential for good outcomes
Malreduction leads to early CMC arthritis
ORIF recommended for displaced fractures

Clinical Implication: CMC articular congruity is the key determinant of outcome for body fractures.

Source: J Bone Joint Surg Am 1960

Level IV

📚 McGuigan FX, Culp RW. Surgical Treatment of Trapezium Fractures

Key Findings:

Fragment excision effective for symptomatic ridge non-union
Screw fixation provides stable body fracture fixation
Early mobilization improves outcomes
FCR tendon assessment important

Clinical Implication: Surgical options include fragment excision for ridge and ORIF for body fractures.

Source: Hand Clin 1998

Level IV

📚 Ramoutar DN et al. Ridge Fractures of the Trapezium

Key Findings:

Ridge fractures often missed without proper imaging
Carpal tunnel view (Roberts) essential
Conservative treatment successful in most
Fragment excision reliable for symptomatic cases

Clinical Implication: Requesting the correct radiographic view is essential for diagnosing ridge fractures.

Source: J Hand Surg Eur 2014

Level IV

📚 Innes L et al. Long-term Outcomes Following Trapezium Fractures

Key Findings:

Body fracture malreduction predicts CMC arthritis
Ridge fractures have excellent long-term prognosis
Step-off over 2mm associated with poor outcomes
Early intervention improves results

Clinical Implication: Long-term outcomes depend on achieving and maintaining anatomic reduction for body fractures.

Source: J Hand Surg Eur 2015

The evidence supports distinct management approaches for ridge and body fractures.

Viva Scenarios

Exam Viva Scenarios

Practice these scenarios to excel in your viva examination

VIVA SCENARIOStandard

Trapezium Fracture Diagnosis

EXAMINER

"A 30-year-old man presents after falling during boxing with pain over the thenar eminence. Standard PA and lateral radiographs are reported as normal. What do you do next?"

EXCEPTIONAL ANSWER

This presentation raises concern for a trapezium fracture, which can be missed on standard radiographic views. **Clinical Assessment:** I would examine for specific signs of trapezium injury - point tenderness over the volar thenar eminence (suggesting ridge fracture) or dorsal CMC joint (suggesting body fracture). I would assess FCR tendon function and look for pain with resisted wrist flexion. **Imaging Strategy:** Standard PA and lateral views often miss trapezium fractures, particularly ridge fractures. I would request a carpal tunnel (Roberts) view - this is obtained with the wrist hyperextended and the beam angled 25 degrees. This view is essential for visualizing the volar ridge. If clinical suspicion remains high after specialized views, I would obtain a CT scan. This will detect occult fractures and characterize any body fracture pattern for surgical planning. **If Ridge Fracture Confirmed:** I would treat with a thumb spica cast or splint for 4-6 weeks. Ridge fractures are extra-articular with excellent prognosis. I would counsel the patient that 10-20% develop symptomatic non-union, which can be treated with fragment excision if needed. **If Body Fracture Confirmed:** I would obtain CT for detailed assessment. If undisplaced, immobilization in a thumb spica cast with serial imaging. If displaced (over 2mm articular step-off), I would recommend ORIF to restore CMC articular congruity and prevent post-traumatic arthritis. **Key Teaching Point:** The carpal tunnel view is essential for trapezium fracture diagnosis and should be specifically requested when this injury is suspected.

KEY POINTS TO SCORE

Standard views often miss trapezium fractures

Carpal tunnel (Roberts) view essential for ridge fractures

CT for body fracture characterization

Ridge vs body determines treatment approach

COMMON TRAPS

✗Accepting normal standard X-rays as excluding fracture

✗Not requesting carpal tunnel view

✗Missing body fracture that requires ORIF

LIKELY FOLLOW-UPS

"How do you obtain the carpal tunnel view?"

"What is the significance of FCR tendon symptoms?"

"What articular step-off threshold indicates surgery?"

VIVA SCENARIOChallenging

Displaced Trapezium Body Fracture

EXAMINER

"CT confirms a vertical body fracture of the trapezium with 3mm of articular step-off at the CMC joint. How do you manage this injury?"

EXCEPTIONAL ANSWER

This is a displaced trapezium body fracture with significant articular involvement requiring surgical treatment. **Injury Assessment:** A vertical body fracture with 3mm step-off is analogous to a Bennett's fracture in its implications for the CMC joint. The step-off exceeds the 2mm threshold associated with good outcomes, and the CMC joint is the most important joint for thumb function. **Indications for Surgery:** With 3mm of articular incongruity, conservative treatment would result in post-traumatic CMC arthritis. I would recommend ORIF to restore articular congruity. **Surgical Planning:** Based on CT, I would plan my approach - dorsal is most common for vertical body fractures. I would assess fragment size to determine if screw fixation is possible or if K-wires are needed. **Surgical Technique:** Through a dorsal approach between EPB and EPL, protecting radial sensory nerve branches, I would perform a capsulotomy to visualize the CMC articular surface. I would reduce the fracture anatomically under direct vision and confirm with fluoroscopy. For a vertical split, a headless compression screw provides excellent fixation if the fragment is large enough. I would aim for step-off under 1mm. **Postoperative Care:** Thumb spica splint for 2 weeks, then cast for 4 weeks. Radiographs at 6 weeks, and if healed, begin protected ROM. K-wire removal at 6 weeks if used. Full activities by 12 weeks. **Prognosis:** With anatomic reduction, outcomes are generally good. I would counsel about the importance of achieving and maintaining reduction to prevent CMC arthritis.

KEY POINTS TO SCORE

Over 2mm step-off requires ORIF

CMC articular congruity is key outcome determinant

Dorsal approach for most body fractures

Headless screws for larger fragments

COMMON TRAPS

✗Treating displaced body fracture conservatively

✗Accepting non-anatomic reduction

✗Not warning about CMC arthritis risk

LIKELY FOLLOW-UPS

"What is your preferred surgical approach?"

"How do you assess adequacy of reduction?"

"What is your approach if the patient develops CMC arthritis?"

VIVA SCENARIOStandard

Symptomatic Ridge Non-Union

EXAMINER

"A patient presents 4 months after a trapezium ridge fracture. Despite casting, they have persistent volar wrist pain that worsens with gripping. X-rays confirm non-union. How do you manage this?"

EXCEPTIONAL ANSWER

This patient has symptomatic non-union of a trapezium ridge fracture, which occurs in 10-20% of cases. **Clinical Assessment:** I would confirm the symptoms are related to the ridge fracture by examining for point tenderness over the volar trapezial ridge and testing FCR function. Pain with resisted wrist flexion suggests FCR involvement, which is common due to the tendon's relationship to the ridge. **Imaging Review:** I would review the carpal tunnel view radiograph to confirm the non-union and assess fragment size. I would also assess for any FCR tenosynovitis, though this is a clinical diagnosis. **Conservative Trial:** If not already attempted, I would try a period of splinting with anti-inflammatory medication. A corticosteroid injection in the FCR sheath may provide temporary relief and help confirm the diagnosis. However, at 4 months with ongoing symptoms, surgical excision is likely needed. **Surgical Treatment:** I would recommend volar ridge fragment excision. Through a volar approach over the FCR tendon at the wrist crease, I would incise the FCR sheath, retract the tendon, and identify the non-united fragment. I would excise the fragment completely, smooth the bony bed, and inspect the FCR tendon for any damage or tenosynovitis requiring debridement. **Postoperative Care:** Light splint for 1-2 weeks, then progressive ROM. Most patients return to full activities by 6 weeks. Outcomes are excellent, with over 95% pain relief. **Key Point:** Ridge fragment excision is a reliable procedure for symptomatic non-union. The patient should expect complete resolution of symptoms.

KEY POINTS TO SCORE

Symptomatic ridge non-union in 10-20%

FCR involvement common due to anatomic relationship

Fragment excision is definitive treatment

Excellent outcomes expected

COMMON TRAPS

✗Prolonged conservative treatment when excision needed

✗Not assessing FCR tendon at surgery

✗Missing body fracture component

LIKELY FOLLOW-UPS

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

"What is the expected time to return to full activities?"

"What would you do if the FCR tendon is damaged?"

MCQ Practice Points

Fracture Pattern Distribution

Q: What is the most common trapezium fracture pattern? A: Volar ridge fractures are the most common pattern, occurring in the FCR groove. Body fractures involving the CMC joint are less common but more clinically significant.

Essential Radiographic View

Q: Which radiographic view is essential for diagnosing trapezium ridge fractures? A: The carpal tunnel (Roberts) view is essential. Obtained with wrist hyperextended and beam angled 25 degrees, it demonstrates the volar ridge that is obscured on standard PA and lateral views.

FCR Tendon Relationship

Q: Why is the FCR tendon at risk with trapezium ridge fractures? A: The FCR tendon passes through a groove bounded by the volar ridge. Ridge fractures can cause FCR tenosynovitis or rupture, and this relationship must be considered in management.

Body Fracture Step-Off Threshold

Q: What articular step-off threshold indicates ORIF for trapezium body fractures? A: Articular step-off greater than 2mm is the threshold for surgical intervention. Malreduction predicts post-traumatic CMC arthritis.

Symptomatic Non-Union Rate

Q: What percentage of trapezium ridge fractures develop symptomatic non-union? A: Approximately 10-20% develop symptomatic non-union. These are effectively treated with fragment excision.

Ridge Fracture Treatment

Q: What is the definitive treatment for symptomatic trapezium ridge non-union? A: Fragment excision through a volar approach. This is a straightforward procedure with excellent outcomes in over 95% of cases.

Understanding these key concepts will help with exam success.

Australian Context

Trapezium fractures are encountered across Australian emergency departments and orthopaedic practices. Sports injuries including boxing, AFL, and contact sports, as well as workplace falls, represent common mechanisms in the Australian population.

Australian radiology departments are familiar with the carpal tunnel (Roberts) view, though it must be specifically requested. Education of emergency and primary care physicians about requesting this view when trapezium fracture is suspected helps avoid missed diagnoses.

Conservative management with thumb spica casting follows international guidelines, with good access to hand therapy services for rehabilitation. Surgical management of displaced body fractures is available at major trauma centers and through hand surgery subspecialists.

The Australian Hand Surgery Society provides resources and continuing education for managing these injuries. Most surgeons use headless compression screws for body fracture fixation when fragment size permits.

Workers compensation pathways support appropriate treatment for occupationally-acquired trapezium fractures. The generally good prognosis for ridge fractures and favorable outcomes for appropriately-treated body fractures mean most patients return to previous activities.