JONES FRACTURES
Zone 2 | Metadiaphyseal Junction | Watershed Zone | High Nonunion Risk | Athletes Need Surgery
TORG CLASSIFICATION (RADIOGRAPHIC STAGING)
Critical Must-Knows
- Zone 2 location: metadiaphyseal junction extending INTO 4-5 intermetatarsal articulation
- Watershed blood supply - nutrient artery meets periosteal supply = poor healing
- 25-50% nonunion rate with conservative treatment (non-athletes may accept this)
- Athletes require surgery - faster healing, lower nonunion, earlier return to sport
- Screw technique critical - entry at tip of tuberosity, largest diameter (minimum 5.5mm), engage far cortex
Examiner's Pearls
- "Jones fracture vs avulsion: Jones extends INTO 4-5 intermetatarsal joint, avulsion proximal to it
- "Watershed zone = poor blood supply = high nonunion = need surgical fixation in athletes
- "Conservative treatment = 6-8 weeks NWB cast = 25-50% nonunion = acceptable in sedentary patients
- "Screw size matters - 5.5mm better outcomes than 4.5mm (Porter 2009)
- "Bone graft for Torg Type II-III (delayed/nonunion) presentations
Clinical Imaging
Imaging Gallery
Critical Exam Points for Jones Fractures
Zone 2 Location
At metadiaphyseal junction, extends INTO 4-5 intermetatarsal articulation - this defines the Jones fracture
Watershed Blood Supply
Nutrient artery meets periosteal supply here = poor healing = high nonunion
Torg Classification
Type I - screw alone. Type II/III - need bone graft for sclerotic canal
Athlete Management
Early surgery = 8-10 week return vs 15+ weeks conservative
At a Glance: Quick Decision Guide
| Feature | Zone 1 (Avulsion) | Zone 2 (Jones) | Zone 3 (Stress) |
|---|---|---|---|
| Location | Tuberosity | Metadiaphyseal junction | Proximal diaphysis |
| Mechanism | Inversion injury | Acute or stress | Repetitive loading |
| Key Landmark | PROXIMAL to 4-5 IM joint | Extends INTO 4-5 IM joint | DISTAL to 4-5 IM joint |
| Nonunion Risk | Low (under 5%) | HIGH (25-50%) | Very High (over 50%) |
| Treatment | Conservative | Consider surgery | Usually surgical |
| Athlete Protocol | CAM boot 4-6 weeks | IM screw fixation | IM screw + graft |
JONESJONES - Key Features
Memory Hook:JONES fractures need a JONES approach - Junction location, Often surgical, Nonunion risk, Entry point critical, Screw size important
Overview and Epidemiology
Jones Fractures - Fifth Metatarsal Zone 2
The Jones fracture is a fracture at the metadiaphyseal junction of the fifth metatarsal base (Zone 2), first described by Sir Robert Jones in 1902. It is notorious for its high nonunion rate and prolonged healing time, making it a critical exam topic.
Anatomy/Biomechanics
Fifth Metatarsal Anatomy - Zone 2
Zone 2 - The Critical Location
Anatomical Boundaries:
- Proximal: Level of 4-5 intermetatarsal articulation
- Distal: Junction of metaphysis and diaphysis
- Key feature: Fracture line extends INTO the 4-5 intermetatarsal joint
Zone Differentiation - Exam Critical
How to differentiate Zone 1 from Zone 2:
| Feature | Zone 1 (Avulsion) | Zone 2 (Jones) |
|---|---|---|
| Location | Proximal to 4-5 joint | At/Into 4-5 joint |
| Mechanism | Inversion avulsion | Adduction force |
| Blood supply | Good (cancellous) | Watershed (poor) |
| Nonunion risk | Under 5% | 25-50% |
| Treatment | Almost always conservative | Athletes need surgery |
The key radiographic landmark: Does the fracture line extend INTO the 4-5 intermetatarsal articulation? If YES = Jones (Zone 2).
Classification
Torg Classification
The Torg classification is the most widely used system for Jones fractures, based on radiographic appearance and indicating chronicity.
TORGTORG - Radiographic Classification
Memory Hook:TORG tells you if bone Graft is needed
Torg Classification - Jones Fractures
| Type | Radiographic Features | Clinical Scenario | Treatment |
|---|---|---|---|
| Type I - Acute | Sharp fracture margins, no medullary sclerosis, no widening | First-time injury, no prodromal symptoms | Cast (non-athletes) or screw (athletes) |
| Type II - Delayed Union | Widened fracture line, evidence of medullary sclerosis | Previous treatment failure, chronic symptoms | IM screw + consider bone graft |
| Type III - Nonunion | Complete obliteration of medullary canal, sclerosis | Established nonunion, chronic pain | Screw + bone graft + curettage of canal |
Zone I - Avulsion
Torg Type II - Delayed
Torg Type III - Nonunion
Treatment Implications by Torg Type
Radiographic Findings:
- Sharp, well-defined fracture line
- No periosteal reaction
- No medullary sclerosis
- Narrow fracture gap
Treatment Options:
Non-Athletes:
- Non-weight-bearing short leg cast
- 6-8 weeks immobilization
- Accept 25-50% nonunion rate
Athletes:
- Primary intramedullary screw fixation
- Faster union (8-10 weeks vs 15+ weeks)
- Lower nonunion rate (under 5% vs 25-50%)
- Earlier return to sport
Proper technique and attention to detail ensure optimal outcomes.
Clinical Assessment
History and Examination
History
Key Questions:
- Mechanism: How did the injury occur? (acute vs insidious)
- Prodromal symptoms: Any previous lateral foot pain? (suggests chronic component)
- Activity level: Athlete vs sedentary (treatment implications)
- Previous injury: Prior fifth metatarsal fracture (risk factor)
- Timing: When did symptoms begin? (acute vs chronic)
Red Flags for Chronic Component:
- Gradual onset of symptoms before acute event
- History of similar pain that resolved
- Prolonged activity-related pain
- Previous treatment for lateral foot pain
Physical Examination
Inspection:
- Lateral foot swelling
- Ecchymosis (lateral foot)
- Comparison with contralateral foot
Palpation:
- Point tenderness over Zone 2 (metadiaphyseal junction)
- Assess entire fifth metatarsal
- Palpate peroneal tendons
Special Considerations:
- Hindfoot alignment - varus predisposes to lateral overload
- Gastrocnemius tightness - Silverskiold test
- Ankle stability - lateral ligament integrity
- Neurovascular status - usually intact
Location of Tenderness
Differentiating by palpation:
- Zone 1 (Avulsion): Tenderness at tuberosity, at peroneus brevis insertion
- Zone 2 (Jones): Tenderness at metadiaphyseal junction, 1.5cm distal to tuberosity
- Zone 3 (Stress): Tenderness more distal, along proximal shaft
Investigations
Imaging
Plain Radiographs
Standard Views:
- AP foot - best view for zone identification
- Lateral foot - assess angulation
- Oblique foot - fifth metatarsal profile
Key Radiographic Features:
- Fracture line location relative to 4-5 joint
- Presence of medullary sclerosis
- Fracture line width
- Periosteal reaction
- Evidence of previous healing attempts
SCLEROSISSCLEROSIS - Signs of Chronicity
Memory Hook:See SCLEROSIS on X-ray = chronic injury = needs bone graft
CT Scan
Indications:
- Assess degree of medullary sclerosis
- Surgical planning for nonunion
- Evaluate for refracture after previous fixation
- Assess healing progress post-operatively
Key Information:
- Medullary canal patency
- Fracture healing
- Hardware position
MRI
Indications:
- Stress reaction without fracture line
- Soft tissue assessment
- Bone marrow edema pattern
- Differentiating acute vs chronic
Findings:
- T1: Low signal at fracture (marrow edema)
- T2/STIR: High signal (edema)
- Chronic: Sclerosis visible
Management
Treatment Algorithm
Management Decision Tree
Key Decision Points:
-
Is the patient an athlete requiring rapid return to sport?
- YES: Surgical fixation (IM screw)
- NO: Consider non-operative if Torg Type I
-
What is the Torg Type?
- Type I: Screw alone may suffice
- Type II: Screw + consider bone graft
- Type III: Screw + bone graft + curettage
-
Has conservative treatment failed?
- YES: Surgical fixation mandatory
- Consider bone grafting
Indications: Sedentary patients, low functional demands, Torg Type I acute fractures, patient accepts 25-50% nonunion risk.
Protocol: Short leg non-weight-bearing cast with strict non-weight-bearing for 6-8 weeks. Serial radiographs every 2-3 weeks. Gradual weight-bearing when radiographic healing seen. Total treatment time 12-20 weeks.
Expected Outcomes: Union rate 50-75%, time to union 15-20 weeks, return to sport 4-5 months if healing occurs.
Surgical Technique
Intramedullary Screw Fixation
Patient Setup: Supine on radiolucent table with bump under ipsilateral hip. Foot must be accessible for fluoroscopy.
Equipment: Fluoroscopy (C-arm), 5.5mm or 6.5mm cannulated screws, guidewires, cannulated drill, and countersink.
Surgical Steps: (1) Approach via direct lateral incision over tuberosity (2-3cm), protecting sural nerve. (2) Entry point critical at tip of tuberosity ("high and medial"). (3) Introduce guidewire under fluoroscopy, confirm central position. (4) Measure screw length, ream if needed (overream 0.5mm). (5) Insert largest screw that fits (5.5mm minimum), engage far cortex. (6) Final check with fluoroscopy AP/lateral/oblique, confirm compression.
Complications
Complications
Risk Factors: Conservative treatment (25-50% rate), Torg Type II-III at presentation, inadequate immobilization, early weight-bearing, smoking, and diabetes.
Treatment: Surgical fixation with bone graft, curettage of sclerotic bone, and consideration of larger screw or plate fixation.
Postoperative Care
Rehabilitation Protocol
Week 0-2: Posterior splint with non-weight-bearing. Elevation and ice for swelling control.
Week 2-6: CAM boot with progressive weight-bearing in boot. ROM exercises out of boot. Pool therapy if available.
Week 6-8: Transition to athletic shoe with full weight-bearing. Progressive strengthening including stationary bike and swimming.
Week 8-10: Sport-specific training begins with cutting and jumping progression. Return to play when criteria met.
Outcomes/Prognosis
Surgical Outcomes
Union rate of 95% with intramedullary screw. Return to sport averages 8-10 weeks. Refracture risk is 7% with 5.5mm+ screw versus 24% with smaller screws. Hardware removal is rarely needed unless symptomatic.
Conservative Outcomes
Union rate of 50-75% for Torg Type I. Time to union is 6-12 weeks if successful. Refracture risk is higher than surgical. Best reserved for non-athletes with Torg Type I fractures.
Outcomes by Torg Classification
| Type | Union Rate (Non-Op) | Union Rate (Surgical) | Return to Sport |
|---|---|---|---|
| Type I (Acute) | 75% | 95% | 8-10 weeks |
| Type II (Delayed) | 50% | 90% (with graft) | 10-12 weeks |
| Type III (Nonunion) | 25% | 85% (with graft) | 12-16 weeks |
Screw Size and Outcomes
Screw diameter is the most important technical factor. 5.5mm screws have 7% refracture rate vs 24% with 4.5mm screws. Always use the largest diameter that fits the medullary canal.
Evidence Base
Key Evidence
Surgical vs Conservative Treatment in Athletes
- 42 Jones fractures in competitive athletes. Surgical group: mean return to sport 8 weeks, 3% nonunion. Conservative group: mean return 15 weeks, 28% nonunion.
Screw Diameter and Refracture Risk
- 59 Jones fractures treated with IM screw. 5.5mm screws: 7% refracture rate. 4.5mm screws: 24% refracture rate.
Torg Classification and Outcomes
- Classic paper establishing the Torg classification. Type I (acute) fractures had better healing potential than Type II-III. Chronic presentations required bone grafting.
Bone Grafting for Delayed Union/Nonunion
- 21 patients with Torg Type II-III fractures treated with IM screw and bone graft. 95% union rate at mean 14 weeks.
Professional Athletes: Return to Play
- 70 NFL players with Jones fractures. Mean return to play 10.6 weeks. Refracture rate 12%. Screw fixation in all.
Viva Scenarios
Exam Viva Scenarios
Practice these scenarios to excel in your viva examination
"A 22-year-old professional basketball player presents with acute lateral foot pain after landing awkwardly. X-rays show a fracture at the metadiaphyseal junction of the fifth metatarsal with the fracture line extending into the 4-5 intermetatarsal articulation. There is no medullary sclerosis."
Diagnosis:
- Jones fracture (Zone 2 fifth metatarsal fracture)
- Torg Type I (acute) - no sclerosis, sharp fracture margins
- Confirmed by fracture extending into 4-5 intermetatarsal joint
Why NOT an avulsion (Zone 1):
- Zone 1 avulsions are PROXIMAL to the 4-5 joint
- This fracture extends INTO the 4-5 joint = Zone 2 = Jones
Management for Professional Athlete:
- Surgical fixation - intramedullary screw
- Faster return to sport (8-10 weeks vs 15+ weeks conservative)
- Lower nonunion rate (under 5% vs 25-50%)
Surgical Technique:
- Direct lateral approach over tuberosity
- Entry point at tip of tuberosity (high and medial)
- Guidewire across fracture, confirm position fluoroscopically
- 5.5mm or larger solid or cannulated screw
- Engage far cortex, countersink head
Postoperative:
- CAM boot, progressive weight-bearing by 2-4 weeks
- Expected return to sport: 8-10 weeks
- Radiographic healing must be confirmed before return
"A 28-year-old recreational runner had a Jones fracture treated conservatively 4 months ago. She remains symptomatic with lateral foot pain on walking. X-rays show widened fracture line with medullary sclerosis but no complete canal obliteration."
Assessment:
- Failed conservative treatment of Jones fracture
- Torg Type II (Delayed Union) - widened line, partial sclerosis
- Persistent symptoms after 4 months = needs intervention
Why Conservative Treatment Failed:
- Jones fractures have inherently poor blood supply (watershed zone)
- 25-50% nonunion rate with conservative treatment is expected
- This is a predictable outcome, not a complication
Treatment Plan:
- Surgical fixation with bone grafting
- Type II fractures benefit from bone graft to address sclerosis
Surgical Technique:
- Lateral approach to fifth metatarsal base
- Curet the fracture site and medullary canal (remove sclerotic bone)
- Harvest bone graft (proximal tibia or iliac crest autograft)
- Pack morselized graft into canal and around fracture
- Intramedullary screw fixation (5.5mm minimum)
- Confirm position fluoroscopically
Expected Outcome:
- Union rate greater than 90% with screw + graft
- Healing expected 10-14 weeks
- Return to running 3-4 months post-surgery
"A 19-year-old soccer player had Jones fracture fixation with a 4.5mm screw 6 months ago. He returned to play at 8 weeks. He now presents with recurrent lateral foot pain. X-rays show a refracture around the previous screw, which remains in place."
Diagnosis:
- Jones fracture refracture around previous fixation
- Risk factors identified: 4.5mm screw (undersized), early return to sport
Why This Happened:
- Screw too small - 4.5mm associated with 24% refracture (Porter 2009)
- 5.5mm screws have only 7% refracture rate
- Early return to play at 8 weeks - may have been premature
- Stress concentration at screw tip
Management Plan:
- Remove previous hardware
- Assess medullary canal - likely has sclerosis (Torg Type II-III pattern)
- Curet canal and remove sclerotic bone
- Bone graft - autograft from proximal tibia or iliac crest
- Revision fixation with larger screw (6.5mm if canal allows)
Alternative if Canal Compromised:
- If medullary canal severely damaged or sclerosed
- Consider plantar plate fixation
- Low-profile locking plate on plantar surface
Prevention for Future:
- Use adequate screw size (5.5mm minimum)
- Wait for radiographic healing before return to sport
- Address any biomechanical factors (hindfoot varus, gastrocnemius tightness)
- Consider leaving hardware in place long-term
MCQ Practice Points
Location Question
Q: Where is the Jones fracture located and what distinguishes it from a tuberosity avulsion?
A: Jones fracture is at the metadiaphyseal junction (Zone 2), extending INTO the 4-5 intermetatarsal joint. Tuberosity avulsion (Zone 1) is PROXIMAL to this joint and involves the peroneus brevis insertion.
Blood Supply Question
Q: Why do Jones fractures have a high nonunion rate?
A: The Zone 2 area is a watershed zone where the nutrient artery (entering from medial cortex) meets the periosteal blood supply. This relatively avascular area compromises healing potential.
Classification Question
Q: How does the Torg classification guide treatment?
A: Type I (acute) - screw alone. Type II (delayed union) - screw plus bone graft. Type III (nonunion) - screw plus bone graft plus curettage of sclerotic bone. The classification is based on radiographic appearance.
Surgical Technique Question
Q: What is the minimum recommended screw size for Jones fracture fixation and why?
A: Minimum 5.5mm diameter. Studies show 4.5mm screws have 24% refracture rate vs 7% with larger screws. Use the largest diameter that fits the canal.
Return to Sport Question
Q: When can an athlete return to sport after Jones fracture fixation?
A: 8-10 weeks with radiographic evidence of healing (bridging callus across 3 of 4 cortices). Earlier return risks refracture, especially with undersized screws.
Australian Context
Jones fractures are commonly seen in the Australian sporting population, particularly in AFL, rugby, and soccer players. The injury typically occurs during rapid change of direction or push-off movements common in these sports.
Management in Australia follows international guidelines with surgical fixation preferred for athletes and active patients. Non-operative management may be considered for Torg Type I fractures in non-athletes, though patients should be counselled about the 25-50% nonunion rate.
Return-to-play decisions should be guided by radiographic healing and clinical assessment. Australian sports medicine physicians and orthopaedic surgeons typically work collaboratively on these cases, with staged rehabilitation programs beginning early post-fixation.
Risk factors relevant to Australian athletes include training load errors, playing surface conditions, and footwear choices. Prevention strategies focus on gradual training progression and addressing biomechanical factors such as hindfoot varus.
Jones Fractures - Exam Day Essentials
High-Yield Exam Summary
Key Numbers
- •Zone 2 = Jones fracture location (metadiaphyseal junction)
- •25-50% = Nonunion rate with conservative treatment
- •5.5mm = Minimum recommended screw diameter
- •8-10 weeks = Return to sport after surgical fixation
- •4-5 joint = Fracture extends INTO this joint
Examiner Favorites
- •Differentiate Jones from tuberosity avulsion (Zone 1 vs Zone 2)
- •Why high nonunion rate? Watershed blood supply
- •Describe Torg classification and treatment implications
- •Surgical technique for Jones fracture fixation
Common Mistakes
- •Confusing Zone 1 (avulsion) with Zone 2 (Jones)
- •Using undersized screw (under 5.5mm) leads to refracture
- •Treating athletes conservatively
- •Not recognizing Torg Type II-III need bone grafting
Exam Day Tips
- •Jones = Zone 2 = fracture INTO 4-5 intermetatarsal joint
- •Watershed zone = poor healing
- •Athletes get surgical fixation
- •Torg I = no graft, Torg II-III = bone graft