Metatarsal Stress Fractures

Patients describe insidious-onset forefoot pain localised to the dorsum of the affected metatarsal. Symptoms are activity-related: worse with walking, running, jumping, and prolonged standing. The classic progression is pain late in exercise, then earlier in exercise, then pain with walking, then pain at rest. Symptoms develop over days to weeks during increased loading, almost always with a training change (increased mileage, new surface, new footwear - particularly minimalist or carbon-plated shoes, or a new programme). For 5th metatarsal Zone 2/3, pain is along the lateral border of the foot at the proximal 5th metatarsal and may present as acute-on-chronic. Always ask about training history, previous stress fractures, RED-S screening (menstrual history in females, energy availability, dietary restriction; in males - low libido, recurrent illness), diet, medications (corticosteroids), smoking, and rheumatoid arthritis.

Examination:

• •Focal, well-localised bony point tenderness is the most important finding. Palpate each metatarsal shaft individually from dorsal. The tenderness is at the bone - not in the intermetatarsal space (Morton neuroma) or directly plantar to the metatarsal head (mechanical metatarsalgia or plantar plate)
• •Dorsal swelling localised over the affected shaft; may be subtle initially
• •Pain on axial loading: longitudinal compression of the metatarsal may reproduce pain at the fracture site
• •5th metatarsal Zone 2/3: focal tenderness at the proximal metaphyseal-diaphyseal junction or proximal diaphysis on the lateral border of the foot. Distinguish from Zone 1 tuberosity tenderness (more proximal) and peroneus brevis tendon tenderness
• •Biomechanical assessment: gastrocnemius tightness (Silfverskiold), foot posture (pes cavus), Morton foot type, hallux rigidus or valgus (transfer loading), ankle dorsiflexion, calf endurance
• •Footwear assessment for worn, thin-soled, minimalist, or recent change to carbon-plated shoes

Red flags: rest or night pain (significant progression - consider urgent imaging); recurrent stress fractures (actively assess for RED-S using IOC REDs CAT2, low BMD with DEXA, and metabolic bone disease); lateral foot pain at the proximal 5th metatarsal (high-risk Zone 2 or 3 must be identified early); pain, swelling, and ecchymosis after an acute loading event on a previously painful foot (acute-on-chronic complete fracture); hot, swollen forefoot with systemic features (exclude septic arthritis, osteomyelitis, gout); progressive forefoot deformity in a diabetic patient (Charcot neuroarthropathy).

If clinical suspicion is high, management should begin even when initial radiographs are normal.

Plain radiographs (AP, lateral, oblique views of the foot) are first-line and readily available, but often normal early - changes take 2 to 6 weeks to appear. For the 5th metatarsal Zone 2/3, plain films may show a fracture line; in chronic stress fractures, sclerosis at the fracture margins and medullary canal narrowing indicate a chronic non-union pattern - a finding that strengthens the case for operative management. Compare with the contralateral foot. X-rays also assess foot alignment.

MRI is the investigation of choice when X-ray is normal and suspicion is high. It detects bone stress injury within days and demonstrates bone marrow oedema (high signal on STIR/T2 fat-suppressed sequences), periosteal oedema, a discrete fracture line, and soft tissue oedema. Findings should be described as stress reaction (oedema without a fracture line) or stress fracture (fracture line present). MRI precisely identifies the fracture site - critical for distinguishing low-risk shaft from high-risk proximal 5th metatarsal.

CT is not first-line but is useful for characterising the fracture line, assessing 5th metatarsal chronicity (sclerosis, canal narrowing - important for surgical planning), and distinguishing acute fracture from non-union.

Point-of-care ultrasound may demonstrate periosteal thickening or elevation or cortical irregularity as a bedside adjunct. A normal scan does not exclude the diagnosis. Bone scan is sensitive but non-specific and is largely superseded by MRI.

Bloods are not routine for an isolated first stress fracture with a clear training error. Consider vitamin D, bone profile, FBC, ferritin, thyroid function, coeliac screen, and reproductive hormones for recurrent, high-risk, or RED-S-suspected presentations. Consider a DEXA scan for recurrent bone stress injuries, prolonged amenorrhoea, or suspected RED-S.

Management depends fundamentally on whether the fracture is low-risk (2nd to 4th metatarsal shaft) or high-risk (proximal 5th metatarsal Zone 2 or 3).

Low-risk metatarsal stress fractures (2nd to 4th shaft, 1st metatarsal shaft):

• •Relative rest with activity modification. Weight-bearing as tolerated in supportive footwear, crutches for comfort if needed. Maintain non-impact fitness with cycling, swimming, aqua jogging, or elliptical
• •Stiff-soled shoe or walking boot may reduce metatarsal bending and improve comfort
• •Pain as a guide. Paracetamol is often preferred; many clinicians are cautious about prolonged oral NSAIDs during active bone healing
• •Identify and address training errors. Optimise bone health. Screen for and address RED-S
• •Progressive return once pain-free with daily activities - typically 6 to 8 weeks. Graduated walk-run programme

High-risk proximal 5th metatarsal stress fractures (Zone 2 and Zone 3):

• •Non-operative management (selected lower-demand patients or those declining surgery): strict non-weight-bearing in a below-knee cast or boot for 6 to 8 weeks with serial X-rays. Return to sport typically 10 to 14 weeks. Non-union rates are notably higher
• •Operative management (athletes and higher-demand patients, or after failed non-operative care): intramedullary screw fixation is the standard surgical treatment. In athletes, early fixation is commonly considered because union is more predictable and return to sport may be faster (approximately 6 to 12 weeks post-operatively). Surgery is also indicated for chronic non-union (sclerosis at fracture margins and medullary canal narrowing may require drilling, curettage, and bone grafting in addition to screw fixation), recurrent fracture, and failed non-operative management
• •Adjuncts for delayed healing or non-union: LIPUS (EXOGEN) is supported by NICE MTG12 for long bone non-union and is used in some UK specialist settings; ESWT has also been used

5th metatarsal tuberosity avulsion (Zone 1, low-risk) is NOT a Jones fracture: weight-bearing as tolerated in a stiff-soled shoe or boot for comfort, progressive return over 4 to 6 weeks.

Bone health optimisation in all cases: check and correct vitamin D deficiency; ensure adequate calcium (1000 mg/day or more); address energy availability. RED-S requires multidisciplinary management using the IOC REDs CAT2 framework.

VTE risk assessment per NICE NG89 should be performed whenever a patient is placed in lower-limb immobilisation (boot or cast), with pharmacological prophylaxis considered when VTE risk outweighs bleeding risk.

Low-risk metatarsal shaft stress fractures (2nd to 4th):

• •Phase 1 (offloading, 0 to 4 weeks): reduce or eliminate impact loading. Weight-bearing as tolerated. Maintain fitness with cycling, swimming, aqua jogging. Non-impact strengthening: calf (particularly soleus), intrinsic foot muscles (short-foot, towel scrunches), hip abductors, core. Address ankle dorsiflexion if restricted. Address bone health and RED-S
• •Phase 2 (progressive loading, 4 to 6 weeks): graduated return to weight-bearing impact. Walking programmes. Progress to walk-run intervals once pain-free walking is established. Continue strengthening. Footwear review
• •Phase 3 (return to running/sport, 6 to 8+ weeks): progressive running with distance before speed. Gradual reintroduction of speed work and sport-specific drills. Continue strengthening as maintenance. Address the original training error

Return criteria: pain-free at the fracture site during and after sport-specific activity, adequate calf and foot strength, good biomechanical control, completion of a graduated programme.

High-risk proximal 5th metatarsal (Zone 2/3):

• •Phase 1 (non-weight-bearing or protected, 0 to 6 weeks): non-weight-bearing in cast or boot (non-operative) or surgeon-specified post-operative protocol. Maintain fitness with upper body, cycling when tolerable, and swimming. Calf and proximal strengthening
• •Phase 2 (progressive weight-bearing, 6 to 10 weeks): graduated weight-bearing, walking programmes, radiographic confirmation of healing, progressive strengthening
• •Phase 3 (return to sport, 10 to 14 weeks non-operative or 6 to 12 weeks post-operative): progressive running, sport-specific drills, continued strengthening, criteria-based return

Prevention: avoid rapid changes in training volume, intensity, or surface exposure. Ongoing calf and intrinsic foot strengthening. Appropriate footwear with regular replacement. Running surface variation. Bone health optimisation (vitamin D, calcium, energy availability). RED-S management - previous stress fracture is the strongest predictor of recurrence.

• •Torg classification (Torg et al., JBJS-Am 1984) - the standard 3-zone classification of proximal 5th metatarsal fractures driving the low-risk versus high-risk distinction.
• •Lawrence and Botte (Foot Ankle Int 1993) - established the modern Zone 2 / Zone 3 vascular watershed concept and high non-union risk in proximal 5th metatarsal stress fractures.
• •NICE MTG12 - supports low-intensity pulsed ultrasound (LIPUS, EXOGEN) for promoting healing of long bone fractures with established or expected delayed or non-union.
• •IOC REDs CAT2 (Mountjoy et al., BJSM 2023) - the standard framework for assessing Relative Energy Deficiency in Sport (RED-S) across both sexes; mandatory in recurrent or unexplained bone stress injury.
• •NICE NG89 - VTE risk assessment is required in patients placed in lower-limb immobilisation, with pharmacological prophylaxis considered when VTE risk outweighs bleeding risk.

• •The 2nd metatarsal is the most commonly affected shaft (longest, most rigidly fixed at the Lisfranc keystone, highest bending stress).
• •Critical distinction: LOW-RISK shaft fractures (2nd-4th) heal well with activity modification; HIGH-RISK proximal 5th metatarsal (Zone 2 Jones region AND Zone 3 proximal diaphysis) have tenuous blood supply, high non-union rates, and often need intramedullary screw fixation.
• •Zone 1 = tuberosity avulsion (acute inversion, low-risk, NOT a Jones fracture). Zone 2 = Jones fracture zone (metaphyseal-diaphyseal junction). Zone 3 = proximal diaphyseal stress fracture zone.
• •A normal X-ray does NOT exclude a stress fracture - MRI is the investigation of choice. Describe findings as stress reaction (oedema only) versus stress fracture (fracture line). Sclerosis with canal narrowing on the proximal 5th indicates chronic non-union.
• •Tight gastrocnemius shifts load onto the forefoot - one of the most important modifiable risk factors (Silfverskiold). RED-S (encompasses the older Female Athlete Triad) is one of the most important systemic risk factors and affects both sexes - use IOC REDs CAT2.
• •Previous stress fracture is the strongest predictor of recurrence. Paracetamol is often preferred over NSAIDs during active bone healing. Carbon-plated running shoes may alter forefoot biomechanics - an emerging modern risk factor. VTE risk assessment per NICE NG89 when immobilised.