Second MTP joint instability and mechanical metatarsalgia of the second ray UPDATED 2026

Clinical synthesis based on the most recent meta-analyses and prospective series: Nery 2012, Albright 2022 (SR/MA imaging), Wang 2022 (SR/MA surgery, 537 patients), Kinter 2020, Coughlin / Maestro classifications.

How is this condition defined, who does it affect and what are the risk factors?

Instability of the second metatarsophalangeal joint (MTP2) is now regarded as one of the most frequent causes of chronic mechanical metatarsalgia in adults.¹² It is a continuum of failure of the structures that stabilise the joint, foremost among them the plantar plate, a thick fibrocartilaginous structure that prevents hyperextension of the MTP joint and keeps the toe aligned.³

Metatarsalgia affects about 10 per cent of the population, with a clear female predominance and a peak after the age of 50.⁴ In the landmark series by Kaz and Coughlin (2007, n=169 crossover deformities), 86 per cent of the patients were women with a mean age of 59 years (33-87).⁵ A recent radiographic study (2024) in women undergoing hallux valgus surgery documented a MTP2 dislocation/subluxation prevalence of 34.9 per cent, significantly higher than in controls.⁶

Risk factors are multifactorial and combine anatomical predispositions with biomechanical constraints:

• long second metatarsal (Maestro index plus): concentrates load on the second metatarsal head during push-off. The reference measurement method remains the one described by Maestro 2003 (Foot Ankle Clin).⁷ Fleischer et al. (2017) showed that a second metatarsal protrusion greater than 4 mm multiplied by 2.5 the risk of plantar plate rupture (n=146, case-control study).⁸
• Hallux valgus: lateral deviation of the great toe reduces its role as the anteromedial pillar and shifts load onto the second ray. The prospective cohort of Coughlin and Jones (2007, JBJS Am) confirmed how often the two are associated.⁹
• First ray hypermobility: tarsometatarsal subluxation of the first ray increases overload of the second ray.¹⁰
• High-impact activities (running, dance, gymnastics, pivoting sports), high-heeled shoes and gastrocnemius equinus.¹¹¹

What happens in the body and how does second MTP joint instability progress naturally?

The pathophysiology is a mechanical continuum: the chronic overload on the second metatarsal head first triggers a synovitis as a reaction, then microtears of the plantar plate, which progressively lengthens and loses its function as a buttress against MTP hyperextension.¹² Yu et al. (2002) popularised the concept of pre-dislocation syndrome to describe this initial phase, often underdiagnosed, in which pain precedes any visible deformity.¹²

The Coughlin classification (first described in 1987 and later refined), taken up by Nery et al. (2012), organises the progression into 5 stages:

The natural history, without intervention, is progressive: Nery et al. (2014, n=55 prospective) described radiographic worsening in more than 60 per cent of the patients followed for 2 years without specific treatment.¹³ This progression leads to stiffness, difficulty with footwear and migration of load towards the third and fourth rays (transfer metatarsalgia), with a marked functional impact.¹⁴

Which questions should you ask to understand the patient and their history?

The history steers the diagnostic hypothesis before any physical examination. The cardinal pain of second MTP joint instability is typically described as a sensation of « walking on a pebble », « a fold in the sock » or « a marble under the foot », localised precisely under the second metatarsal head.¹² This pain is worse on push-off (the terminal stance phase of gait, high heels, running, jumping) and relieved by rest.³ Local oedema that does not settle with rest points to an associated synovitis.⁴

The following should be clarified in every case:

• The mode of onset : insidious (chronic, the typical degenerative instability) or sudden (acute trauma, plantar plate rupture after hyperextension).
• The appearance of a deviation (medial then dorsal, crossover toe): a marker of worsening and of progression towards the higher Coughlin stages.⁵
• The podiatric history : hallux valgus, forefoot surgery, previous corticosteroid injections (iatrogenic risk of rupture).¹
• The footwear habits and sporting activity (running, dance, pivoting sports).
• The red flags : dull night pain, weight loss, fever, palpable mass, history of cancer, all of which call for a medical work-up.⁶

Which clinical tests should be performed and which other conditions must be ruled out?

Clinical examination is the cornerstone of diagnosis. After inspection (deviation, oedema, plantar hyperkeratosis) and targeted palpation (exquisite tenderness under the second metatarsal head, just distal to the phalanx-metatarsal junction), the clinician performs the specific manoeuvres:

• Vertical drawer test (Lachman test of the foot): the reference manoeuvre. The clinician stabilises the metatarsal head with one hand and translates the base of the proximal phalanx vertically with the other. A displacement > 2 mm or > 50 per cent of the joint height compared with the unaffected side defines a positive test. Reported sensitivity is 83-94 per cent in the literature for detecting plantar plate ruptures (Nery 2012, Nery 2017).⁴⁷
• Paper pull-out test: the patient holds a sheet of paper under the toe with active plantarflexion. Weakness points to the intrinsic muscle deficit that is often associated.⁸
• Mulder's test: transverse compression of the metatarsal heads: positive (click + radiating pain) in Morton's neuroma, classically negative in isolated second MTP joint instability.⁹
• Palpation of the intermetatarsal spaces : pain between the heads = Morton; pain under the head = MTP2.

The differential diagnosis is crucial, because the pitfalls are many. The conditions to rule out include:

• Morton's neuroma: pain over the intermetatarsal space (most often the third), Mulder's sign typically positive. Caution: a reactive pseudo-neuroma is possible in chronic second MTP joint instability with pericapsular inflammation.¹⁰
• Stress fracture of the second metatarsal: bony pain, tenderness on palpation of the metatarsal shaft, a context of rapidly increased load. MRI or bone scintigraphy to confirm.¹¹
• Freiberg's disease (Freiberg infraction): avascular necrosis of the second metatarsal head (5:1 female, typically 11-17 years). Plain radiograph: flattening of the head, cystic lesions. MRI: low T1 signal / high T2 signal.¹²
• Inflammatory synovitis (rheumatoid arthritis, spondyloarthritis): involvement is readily polyarticular, with inflammatory blood markers (CRP, RF, ACPA).
• Sesamoiditis of the second ray or MTP osteoarthritis.

Should patients be classified, and what are the benefits?

Yes: classification makes severity objective, standardises communication between clinicians and, above all, helps to guide the treatment decision (conservative at the reducible stages 0-2, surgical at the fixed stages 3-4).⁴¹³ The five-stage Coughlin/Nery classification (see chapter 1) is today the reference standard. An arthroscopic classification from Nery 2015 (grades 0-IV) complements it intraoperatively to quantify the extent of the tear (longitudinal, transverse, medial, complete with retraction).¹⁴

When should MRI or ultrasound be ordered to confirm the diagnosis?

Imaging is not routine: a positive vertical drawer test is usually enough to make the diagnosis and to start conservative treatment. It becomes essential:

• in the event of clinical discordance or of an atypical presentation ;
• when the differential diagnosis is uncertain (Morton, fracture, Freiberg);
• in the pre-operative setting to quantify the extent of the lesion and to plan the surgical approach.

The Albright et al. SR/MA (2022, Eur J Radiol) pooling 11 studies (227 plantar plates on MRI, 238 on ultrasound, operative reference standard) establishes that:

• MRI : pooled sensitivity 89 per cent (95% CI 0.84-0.93), specificity 83 per cent (95% CI 0.64-0.94). The reference examination.
• Dynamic ultrasound : sensitivity 95 per cent (95% CI 0.91-0.98) but specificity of only 52 per cent (95% CI 0.37-0.68). Useful as a screening test (high NPV) but to be read with caution as a confirmatory test.¹⁵

A negative ultrasound in a patient with an equivocal clinical test is reassuring; a positive ultrasound needs MRI confirmation if surgery is being considered.

Where to start? What is the hierarchy of conservative interventions?

Management begins almost always with a conservative approach centred on mechanically offloading the second MTP joint and controlling local inflammation.¹ The review by Kinter and Hodgkins (2020, Sports Health) summarises the validated modalities:²

1. Immediate mechanical offloading: the taping of the second toe in slight plantarflexion limits MTP hyperextension, the main aggravating mechanism. Rapid symptomatic effect (Adams 2016: continuous use in a dancer, with a successful outcome).³
2. Footwear modification: a shoe with a wide and deep toe box, a rigid or rocker sole (rocker sole) to reduce MTP flexion at push-off. Avoid high heels.²
3. Foot orthosis with a retrocapital pad: a metatarsal pad placed behind the second metatarsal head to offload it. This is the standard of care as first-line treatment.²⁴
4. Management of sporting load: temporary reduction of impact activities, offloaded alternatives (swimming, cycling); gradual resumption with the « < 10 per cent / week » rule (Nielsen 2014 JOSPT).⁵
5. Patient education: the nature of the condition, the role of mechanical overload, the importance of adherence.

What is the role of intrinsic foot exercise and which approach is superior?

Therapeutic exercise is the active pillar of management in the medium and long term. The main objective is strengthening of the intrinsic foot muscles (abductor hallucis, lumbricals, flexor digitorum brevis) that make up the « foot core system » (McKeon 2015, BJSM).⁶

The short foot exercise (SFE) is the best-documented intervention: the patient learns to actively shorten the foot by drawing the head of the first metatarsal towards the heel, without curling the toes. Jung et al. (2011, Phys Ther Sport) showed on EMG that the SFE activates abductor hallucis significantly more than a simple toe curl (p<0.001), and that the effect is greater in single-leg stance.⁷ Mulligan and Cook (2013, Man Ther) confirmed in a pilot trial that 4 weeks of SFE significantly increase arch height in subjects with marked collapse.⁸

The meta-analysis by Wei et al. (2022, PLOS One) on 16 studies confirms that intrinsic foot muscle training improves strength and dynamic balance and reduces navicular drop, but the specific effect on pain remains modest, which argues for combining it with an orthosis and taping.⁹

Beyond the foot, adding posterior chain work (triceps surae, gastrocnemius stretching, ankle/hip balance) and control of pronation is useful to reduce the push-off forces focused on the second ray.²

Manual therapies, ESWT, injections: how effective are they really?

Several adjuvant therapies are available; their level of evidence varies widely:

• Manual therapy (intermetatarsal, tarsometatarsal and ankle mobilisations): short-term pain relief reported in case series, low level of evidence (no good-quality RCT specific to the second MTP joint).
• ESWT (extracorporeal shockwave therapy) : a validated option for resistant chronic metatarsalgias (> 3 months). For the second MTP joint specifically, the data remain limited but consistent with the effectiveness seen in other plantar tendinopathies / enthesopathies.
• Corticosteroid injections : their use is controversial. They relieve inflammation but carry a far from negligible risk of rupture of the plantar plate that is already weakened, and of fat pad atrophy, which can worsen the instability in the medium term.²¹⁰ Recent recommendations (Kinter 2020) advise against their routine use and restrict them to very selected situations, under supervision.
• Prolotherapy : used in the Adams 2016 case (a dancer, successful outcome) but with a low level of evidence.³

When should surgery be considered and what results can be expected?

Surgery is indicated at the fixed stages 3-4 or after failure of 3-6 months of well-conducted conservative treatment. The SR/MA by Wang et al. (2022, J Foot Ankle Surg) covering 12 studies that pooled 537 plantar plate tears treated surgically shows:¹¹

• There is a significant improvement in the pain VAS and the AOFAS score at 2 years.
• The dorsal approach (Watson 2014) with direct repair + Weil osteotomy added is the commonest and best-studied combination.¹²
• More than 80 per cent good to excellent results, but a residual stiffness of the MTP joint in about 20 per cent of those operated on: the most frequently reported complication.
• There is a recurrence rate of about 7.6 per cent (Prissel 2017, plantar approach).¹³

The direct plantar approach (Prissel 2017) offers excellent visualisation but exposes the patient to plantar scar complications (up to 10 per cent, Sharpe 2025).¹⁴ In the event of an associated hallux valgus, correcting it at the same time is essential on pain of mechanical failure of the MTP2 repair.¹⁵

How can the patient be made an active partner in their own recovery through self-management?

Self-management (self-management) is the cornerstone of lasting results. Therapeutic education gives the patient the knowledge and skills to manage the condition day to day: understanding the role of overload on the plantar plate, identifying aggravating factors (unsuitable shoes, spikes in activity), and knowing how to react to early symptoms.¹

The key components of self-management are:

• Intrinsic strengthening at home: the patient continues the short foot exercise and toe yoga for 5-10 minutes / day. The Wei 2022 meta-analysis confirms the effects on posture and balance, prerequisites for a good distribution of pressure.²
• Self-monitoring of pain: the patient learns to modulate activity while staying below an acceptable threshold (typically ≤ 3/10 on the NPRS) during and after exercise, with no worsening on waking the next day. This approach allows safe graded exposure.³
• Sensible use of adjuncts: the orthosis and taping are tools of transition, not of dependence. The patient should learn to apply a simple tape job themselves during a flare.
• Footwear modification day to day: lasting avoidance of pointed shoes / high heels for women at risk.⁴

Lin et al. (2020, BJSM) identified 11 consistent recommendations drawn from the most robust MSK guidelines: centre care on the patient, screen for red flags, assess psychosocial factors, use imaging selectively, carry out a physical examination, measure progress, provide education and information, prescribe exercise, use passive modalities as adjuncts only, avoid surgery when it is not needed, and encourage people to stay active.⁵

When and how should a safe return to sport and activity be planned?

Return to sport must be guided by functional criteria and not by a rigid calendar. The decision-rules model validated by Grindem et al. (2016, BJSM) on the Delaware-Oslo ACL cohort (an 84 per cent reduction in re-injury risk through adherence to the functional criteria) provides a solid analogy: wait for symmetry of strength and a minimum delay before returning to pivoting activities.⁶

For the second MTP joint, a structured progression in 3 phases is recommended:

The psychological dimension is decisive. The kinesiophobia, the fear of recurrence and the readiness (psychological preparedness) are major predictors of a successful return to activity. The work of Ardern et al. (2014, BJSM) on the ACL-RSI score documented this dimension in the ACL setting, and it transfers to any return after a foot condition.⁷

The shared decision-making (collaborative decision-making) between physiotherapist and patient must remain central: the patient's personal goals, tolerance of the risk of recurrence, and work and leisure constraints.⁸

Conservative case: resolution without surgery in the dancer described by Adams 2016

The case report by Adams, Pozzi and Wallace (2016, JOSPT, PMID 26755404) describes a 33-year-old professional dancer with insidious pain over the second and third MTP joints, present for several months.¹ Clinical examination showed tenderness on palpation of the metatarsal heads and a positive vertical drawer test, and imaging (MRI) confirmed:

• MTP1 osteoarthritis;
• Calcification + MTP2 capsulitis;
• Rupture of the MTP2 plantar plate (Coughlin stage 2).

The multimodal conservative treatment strategy comprised:

• Taping for protection, holding the second toe in plantarflexion, applied for all physical activity;
• Padding (a retrocapital metatarsal pad) built into the dance shoe;
• Physiotherapy: intrinsic strengthening (short foot, toe yoga), posterior chain work, motor control of the foot, graded exposure to load;
• Activity modification: temporary reduction of jumping, replaced by floor work;
• Courses of prolotherapy, as an add-on (4 injections);
• Follow-up over 37 physiotherapy sessions across 16 weeks.

At discharge, the patient had resumed her professional activity in full (complete choreography), continuing the taping and the padding for performances. This case is emblematic of the conservative therapeutic window of the early stages and of the need for a multimodal approach combining offloading, active strengthening and activity modification.¹

Surgical case: the Nery 2012 prospective series

The founding prospective series of Nery, Coughlin, Baumfeld and Mann (2012, Foot Ankle Int, PMID 22735202) brings together 22 MTP joints with reducible instability (Coughlin stages 1-3) that underwent direct plantar plate repair through a dorsal approach with or without an associated Weil osteotomy.²

Main results:

• Significant improvement in the AOFAS and pain VAS scores ;
• Return to daily activities at about 6-8 weeks;
• High patient satisfaction score at 12 months;
• Most frequently reported complication: residual stiffness of the MTP joint in about 20 per cent of those operated on;
• No recurrence at 12 months in this series.

This series established the dorsal approach as the reference technique, later refined by Watson (2014) and confirmed by the Wang 2022 SR/MA (537 patients).³⁴

The diagnostic challenge: when second MTP joint instability mimics Morton's neuroma

The confusion between second MTP joint instability and Morton's neuroma is the commonest diagnostic error, and its consequences can be serious: the repeated corticosteroid injections given for a presumed « neuroma » on an already weakened plantar plate precipitate complete rupture.⁵

The typical case described in the literature: a middle-aged woman with pain under the forefoot, given corticosteroid injections for a supposed neuroma without lasting improvement. Reassessment reveals:

• Pain under the head of the second metatarsal (not in the 2-3 space);
• Positive vertical drawer test (translation > 2 mm);
• Mulder's sign negative or equivocal;
• Dynamic ultrasound demonstrates the dorsal subluxation of the phalanx + a tear of the plate;
• MRI confirms the rupture.⁶

The trap is all the more common because the two conditions can coexist : chronic instability of the second MTP joint generates a reactive pseudo-neuroma (pericapsular thickening) that can be mistaken for a true intermetatarsal neuroma on imaging.⁵

Complex case study: hallux valgus + plantar plate tear + combined surgery

Complex cases illustrate the multifactorial aetiology of second MTP joint instability and the need for a comprehensive surgical approach. Vakhshori et al. (2022, Foot Ankle Surg) documented that 34.9 per cent of the women operated on for hallux valgus had a concomitant MTP2 subluxation, against 0 per cent in the matched controls: a highly significant difference.⁷

In these situations, the simultaneous correction of the hallux valgus (scarf, chevron or Lapidus osteotomy depending on the context) AND of the MTP2 plantar plate (dorsal repair + Weil) is essential on pain of mechanical failure. Neglecting the hallux valgus exposes the patient to recurrence of the second MTP joint instability within 12-18 months, because load remains badly distributed.⁸

The Adams 2016 case already cited illustrates another form of complexity: multi-joint involvement (MTP1 osteoarthritis + second MTP joint instability + capsulitis) in a dancer, where surgery would have compromised her career and where the multimodal conservative approach allowed a return to performance.¹

Critique and controversies: the place of the clinical case

Case reports have well-identified limitations:

• Publication bias: successful cases are over-represented compared with failures;
• Level V evidence (CEBM), no causality and no generalisation are possible;
• Heterogeneity of reporting, no universal standardisation of outcomes;
• Over-representation of surgery: a relative shortage of detailed conservative cases with confirmatory imaging (the Adams 2016 case stands out as a remarkable exception).

Clinical cases are an excellent teaching tool and a good way to expose pitfalls, but major treatment decisions must rest on SR/MAs (Maas 2016, Albright 2022, Wang 2022, Wei 2022) and large prospective series.

When and to which other healthcare professionals should you refer?

One of the key skills of the physiotherapist working in direct access is the identification of situations that fall outside their scope of practice. This triage rests on two registers: red flags (suspected serious pathology) and yellow flags (psychosocial factors that predict chronicity).

The international framework of Finucane et al. (2020, JOSPT) stresses that red flags taken in isolation have a low positive predictive value: it is their clustering (a constellation) that should raise the alarm and prompt a rapid referral.¹ For the forefoot, the signs to take in are: dull night pain, a firm immobile mass, redness-fever-swelling (suspected infection / Charcot foot in diabetes), a history of cancer, unexplained weight loss, and polyarthritis with prolonged morning stiffness.

Referral should therefore be considered in these scenarios:

• To a general practitioner, podiatrist, rheumatologist or orthopaedic surgeon : red flags present, no progress after 3-6 months of well-conducted conservative treatment, severe deformity (Coughlin stages 3-4), discussion of interventional alternatives (ESWT, surgery).²
• To an orthotist / specialised podiatrist : design and fitting of a custom foot orthosis with a good retrocapital pad (Chapman 2018 confirms similar effectiveness between custom and well-fitted prefabricated devices, but the fitting calls for expertise).³
• To a psychologist / CBT approach : predominant yellow flags (marked kinesiophobia, catastrophising, interfering depressive symptoms) that hold recovery back.⁴
• To a pain specialist / multidisciplinary team : complex chronic pain, suspected central sensitisation, multiple comorbidity.⁵

The interprofessional collaboration is a quality-of-care factor recognised by the guidelines (Lin 2020): clear referral protocols, shared reports, shared decision-making with the patient.⁶

How do you measure outcomes and overcome barriers to implementation?

Measuring outcomes objectively is essential to justify continuing treatment, adjust management and document progress. The validated PROMs for metatarsalgia are:

• NPRS (Numeric Pain Rating Scale, 0-10): pain intensity, MCID about 2 points;
• FAAM (Foot and Ankle Ability Measure): 29 items + 8 sport items, validated for foot/ankle function;
• FFI (Foot Function Index): pain + disability + activity limitation;
• AOFAS (American Orthopaedic Foot & Ankle Society score): much used in surgery but criticised for its limited psychometric properties.

Systematic use of these tools allows tracking over time and shared decision-making. Their implementation in daily practice runs into several classic barriers, however:

1. Barriers on the therapist's side: lack of time, little familiarity with the tools, residual biomedical beliefs, the inertia of habit;
2. Barriers on the patient's side: expectations geared towards passive techniques, low health literacy, socio-economic constraints;
3. Systemic barriers: reimbursement of passive modalities rather than education/exercise, lack of organisational support, imperfect interprofessional communication.⁶

The 11 cross-cutting recommendations identified by Lin et al. (2020) for MSK conditions apply without reservation to the second MTP joint: (1) patient-centred care, (2) red flag screening, (3) yellow flag assessment, (4) selective imaging, (5) full physical examination, (6) monitoring of progress, (7) education and information, (8) exercise prescription, (9) passive modalities as adjuncts only, (10) surgery as a last resort, (11) staying active encouraged.⁶

Critique and controversy: beyond the simple application of the recommendations

Several nuances need to be taken on board:

• The « tyranny of red flags » is an emerging criticism: an excessive, anxiety-provoking search can paradoxically increase the use of unnecessary imaging, generate iatrogenic anxiety and reinforce negative beliefs about the « fragility » of the body. The skill lies in the ability to reassure as much as to raise the alarm.¹
• The theory/practice gap in the biopsychosocial model remains wide: many therapists say they have adopted it but in practice stay focused on the biomechanical side. Addressing yellow flags calls for advanced communication skills.⁵
• The reduction of the patient to a score through PROMs: better numbers do not amount to the patient's own satisfaction: PROMs are a starting point for the conversation, not an end in themselves.
• The rigid application of the recommendations must always leave room for individualisation: goals, sporting and occupational context, patient preferences.