It is a common cause of pain at the base of the 2nd toe at the level of the 2nd metatarsophalangeal (MTP) joint.

Before describing the condition, you may wish to read about the normal anatomy of the lesser toes here.

2nd MTP joint instability is associated with inflammation and injury to the joint capsule, ligaments and in particular a structure known as the plantar plate.

MRI of the Plantar Plate (arrow), contrast has been injected into the MTP joint which has leaked outside of the joint indicating a tear in the plantar plate

The plantar plate is a thick ligament that attaches the ball of the 2nd metatarsal to the base of the 2nd toe. It provides stability and support to the 2nd MTP joint and prevents dislocation of the toe.

As the condition progresses the 2nd MTP joint becomes increasingly unstable. Eventually the toe starts to deviate and eventually can cross over or under the big toe.

The final stage of 2nd MTP joint instability is crossover deformity of the 2nd toe on to the big toe and dislocation at the 2nd MTP joint as shown in this clinical picture

No one knows the exact cause for 2nd MTP joint instability. We do know that multiple factors are involved.

Some patients develop 2nd MTP joint instability due to isolated inflammation (synovitis) of the 2nd MTP joint. This maybe due to arthritis, trauma or overload of the 2nd MTP joint. Some studies also suggest a relationship with a long 2nd toe (metatarsal). The most common cause is idiopathic, which means “arises spontaneously and of unknown cause”.

Problems with the big toe such as a bunion (Hallux Valgus) or 1st MTP joint arthritis (Hallux Rigidus) are also associated with 2nd MTP joint instability. This occurs in the latter two because the big toe joint (1st MTP) does not work properly. In a normal foot the 1st MTP joint takes roughly 40-50% of the load as you walk. This load is transferred to the 2nd and to varying degrees the other lesser toes. As the 2nd toe joint is not designed to take this load, damage can occur at the 2nd MTP joint.

Tight calf muscles (gastrocnemius) are not known to cause 2nd MTP joint instability, however we mention it as it can exacerbate the problem. Tight calf muscles result in increase load across the front of the foot, this puts more strain on already damaged structures such as the plantar plate ligament. Addressing calf tightness is important in the treatment of 2nd MTP joint instability.

In summary the following are associated with 2nd MTP joint instability:

• Idiopathic
• Acute trauma (plantar plate rupture following forced hyperextension with axial loading)
• Long 2nd metatarsal
• Hypermobility of the first ray (1st metatarsal)
• Flat feet
• Bunion (Hallux Valgus)
• Big toe joint arthritis (Hallux Rigidus)
• Steroid injection into the area

Pain is by far the commonest symptom. Pain may be felt in the “ball” of the 2nd toe joint, on the plantar (sole) aspect of the foot. Patients often describe it as walking on a marble. Pain may also be felt across the dorsum (top) of the foot at the 2nd MTP joint. It is also often felt where the 2nd toe rubs against the roof of the toe box in footwear.

Swelling may be present particularly as the condition progresses, and there may be increased warmth in the joint.

Deformity occurs later as the disease progresses. The 2nd toe elevates initially, a hammer toe deformity (flexion at the PIP joint and extension at the MTP joint) frequently occurs and finally the toe crosses over.

The right 2nd toe is elevated, while the left foot demonstrates failure of taping

Callosity can form under the 2nd MTP joint. This is normal thickening of the skin in response to abnormal load and pressure. These can become painful.

Focal painful callosity under the 2nd MTP joint

Ulceration can occur either on the dorsum of the 2nd toe at the level of the PIP joint where it rubs against footwear. An ulcer can also form on the sole of the foot (plantar aspect of 2nd MTP joint). These can become infected and cause deep infection, sometimes even of the bone.

Often a patients main complaint is difficulty finding footwear that fits and pain where the 2nd toe rubs against shoes

Examination initially may reveal nothing but tenderness across the 2nd MTP joint. As the condition progresses swelling can occur, and the 2nd toe starts to drift (medially) towards the big toe. Later the 2nd toe crosses over or under the big toe. Thickening of the skin (callosity) under the 2nd MTP joint is typically a manifestation of increased load and forces going through the joint. The callosity may be painful and attempts to remove it will be temporary as the skin will thicken again in response to the abnormal load.

Radiographs will be arranged at your initial clinic consultation. These will help confirm the diagnosis, the severity of the deformity and aid in pre operative planning.

Radiographs

Radiographs (x-rays) are a useful first line investigation to rule out any other problems in the forefoot. They may be normal in the early stages of the condition. The 2nd MTP joint may appear distended.  In later stages of the condition there is dorsal and medial subluxation of the toe.

Radiograph of left foot demonstrating 2nd MTP joint instability

Ultrasound

Ultrasound is used to confirm swelling (synovitis) in the 2nd MTP joint, and to see if there is anything else that may be causing the symptoms for example, Morton’s neuroma or intermetatarsal bursitis.

MRI

MRI is useful especially in the early stages of the condition when x-rays may appear normal. It provides excellent high definition static images.

MRI is particularly useful in assessing:

• Cartilage damage
• Reactive bone changes (stress response)
• Synovitis (inflammation and fluid in the joint)
• Damage to the plantar plate
• Other pathology

An MRI of the foot demonstrating inflammation (synovitis) in the 2nd MTP joint

An MRI in combination with a small injection can help confirm any injury to the plantar plate (if there is a tear, fluid leaks out of the 2nd MTP joint, see image below), it can also confirm any stress lesions in the bone itself. If the underlying diagnosis is not clear an MRI can be a useful investigation.

MRI of the foot demonstrating leaking out of dye injected into the 2nd MTP joint indicating that there is a likely tear in the plantar plate and capsule

2nd MTP joint instability is a condition that can get worse over time.

The following is a classification used for this condition:

• Stage 1 – Synovitis and mild deviation of the 2nd toe
• Stage 2 – Dorsomedial deviation (subluxation) of the 2nd toe
• Stage 3 – Overlapping of the big toe (hallux)
• Stage 4 – Complete dislocation at the 2nd MTP joint

As the disease progresses so does the deformity. Most patient with stage 3 & 4, 2nd MTP joint instability develop a hammer toe deformity as well.

The following are radiographs taken over 3 years with a patient with 2nd MTP joint instability:

A radiographic showing pain in the 2nd MTP joint

Mild medial deviation of the 2nd toe

Subluxation at the 2nd MTP joint

MRI showing dislocation at the 2nd MTP joint with attenuation of the plantar plate

The patient eventually underwent surgical correction with a plantar plate repair and had a good result in terms of deformity correction, restoration of normal anatomy and pain relief

Non-operative management aims at relieving pain and possibly preventing disease progression. It is likely to be most effective in Stage 1 of the disease process.

It should always be the first line of treatment. Options include:

Activity modification

A period of rest from sports and exercise that bring on symptoms. Avoiding high impact activities and sports that involve lots of turning, twisting and bending of the toes such as running, dancing, basket ball etc.

Toe sleeves

Made of silicon can be worn over the toe to protect from direct pressure and rubbing against footwear.

Taping/strapping

Position the toe in neutral alignment using cross over taping or toe straps. Provide stability to the joint and alleviate symptoms. If there is no deformity then taping may allow healing to occur. If deformity is present, then prolonged taping will not correct this.

An example of taping which has failed to correct 2nd MTP Joint deformity

Insoles & orthotics

An insole with a metatarsal dome pad just proximal to the 2nd MTP joint can take some of the pressure off the joint and alleviate the pain. Stiffening the area under the 2nd metatarsal head with an orthoses can reduce the forces across the 2nd MTP joint. A rocker bottom sole may also help relieve dorsiflexion of the toe, which again would reduce the forces across the 2nd MTP joint. An insole that has a recess for a callosity may also reduce pain.

Non steroidal anti-inflammatories

The use of non-steroidal anti-inflammatory drugs (NSAIDs) can decrease discomfort from an inflamed synovitic 2nd MTP joint.

Footwear Modification

The use of stiff soled shoes that do not bend and therefore protect the 2nd MTP joint.

Physiotherapy

Stretching tight calf muscles will help reduce the forces going across the forefoot. This will help reduce pain in the 2nd MTP joint.

Surgical management is reserved for patients who have failed to respond to non operative treatment.

Patients should understand that the decision to undergo surgery should not be taken lightly.

Any intervention is considered in a step wise manner, with the least invasive procedure carried out first.

A variety of surgical options exist which need to be tailored to the individual and the stage of the disease. In general, mild deformities can be treated by soft tissue procedures; severe deformities may require the addition of a bony corrective surgery (resetting the bone).

One or more of the following may be required to correct a deformity.

Soft tissue procedures

• MTP joint capsular release – Over time the joint capsule tightens up, releasing the capsule allows the toe to return to a more normal position.
• Extensor tendon lengthening – Releasing these tight tendons allows the toe to return to a more normal position.
• FDL flexor to extensor tendon transfer (Girdlestone-Taylor procedure) – This procedure involves releasing one of the tendons that pulls the toe downwards (FDL) at the end of the toe. the tendon is then transferred to the top of the toe (dorsal aspect of the proximal phalanx and extensor hood). This procedure aims to convert one of the primary deforming forces that results in clawing of the toes into a corrective force. It is a technically more demanding operation and recovery is slightly longer as a result.

Bone procedures

• Shortening osteotomy of the 2nd metatarsal (Weil’s osteotomy) – By shortening the metatarsal bone the aim is to correct the imbalance in the soft tissues indirectly.
• PIP joint fusion/arthroplasty – Bringing the toe down is not enough in a fixed deformity, the fixed bend at the PIP joint has to be corrected and this is done by removing some of the joint and fusing the toe in a corrected straightened position. It is not unusual for this joint not to fully heal with bone, but even a fibrous union (scar tissue) in a straight position will be effective in the majority of patients. The bones are held in place by a temporary metal wire (K-wire) which is removed at roughly 4-6 weeks.

Combined soft tissue and bone procedure

• Minimally invasive technique
  • Soft tissue releases percutaneously (2nd MTP joint capsule, EDL and PIP plantar plate).
  • Basal plantar closing wedge osteotomy to proximal phalanx.
• Plantar plate repair

Chronic Dislocation

• May require transfixing the toe to the metatarsal with a K wire (temporary metal wire).
• In the presence of severe infection or uncorrectable deformity resulting in significant symptoms, rarely an amputation may be considered.

In summary the aim of surgery is to correct the deformity, alleviate pain and return a patient to full function.

Before and after radiographs of a patient who had a plantar plate repair

It should be borne in mind that complications can result from a condition with or without surgery.

Potential complications of non-operative treatment include:

• Worsening pain
• Increasing deformity
• Dislocation of 2nd toe
• 2nd MTP joint arthritis
• Crossover toe deformity
• Formation of ulcers on the sole of the foot (plantar aspect of 2nd MTP joint)
• Formation of ulcers across the top (dorsum) of the second toe as it rubs against the shoe
• Failure of taping
• Infection of ulcers
• Transfer metatarsalgia

A – Clinical picture of crossover toe with corresponding B – x-ray of the foot, note severe hallux valgus deformity and dislocation at the 2nd MTP joint instability

This patient had an ulcer form at the site of their callosity which subsequently became infected

Complications can occur as with any type of surgery. Please see foot and ankle complications for more detailed explanation of post surgical complications.

Potential complications of operative treatment include:

• Risks and complications of anaesthesia
• Bleeding
• Infection (superficial and deep)
• Blood clots
• In the case of an MIS procedure it may be necessary to proceed to open surgery if during the operation it is felt that a better outcome will be achieved using an open technique
• Failure to fully correct deformity (particularly if longstanding deformity)
• Recurrence of the deformity
• Stiffness of the 2nd MTP joint
• Arthritis of the 2nd MTP joint
• Wound healing problems (particularly when correcting a chronic dislocation the soft tissue can become contracted)
• In chronic deformity the blood vessels contract, straightening the toe stretches these vessels potentially compromising the blood supply
• Complex regional pain syndrome
• Nerve injury
• Need for further surgery

Note – this list is not exhaustive and is meant as a guide

Please read the information regarding what to expect post surgery on this website.

Remember that below is a guide to recovery and that everyone heals at different rates and some people do take longer. Use this information to help you understand your condition, possible treatment and recovery. The timeframes given below are a minimum, it is important that you appreciate this when considering surgery as your healing and recovery may take longer.

Immediate post operative period

Almost all surgical procedures for 2nd metatarsal instability will be undertaken as a day case.

You will have a bandage applied similar to this during the operation.

Post operative foot bandage

Please do not remove your bandages until you are seen by your surgeon Mr Malik at the two week post operative clinic appointment. You will also be provided with a stiff soled black post operative shoe. Please ensure you wear this whenever you are weight bearing.

Post operative stiff soled shoe

For the first 48 hours you will be allowed to touch weight bear using two crutches. After 48hrs you can weight bear as tolerate. The physiotherapist will guide you after your operation and before your discharge from hospital with the use of crutches and mobilising.

For the first two weeks following your surgery please keep your foot elevated to the level of your heart for 95% of the time. It is recommended you stay at home during this period.

High elevation of the foot and ankle following a surgical procedure

Naturally most people do not have a hospital bed at home. The same effect can be achieved by lying in a bed or lengthways on a sofa, with pillows behind your back and under your foot. You cannot have your leg elevated sitting in a chair. It is strongly advised that during the first two weeks you are house bound.

To minimise risk of infection keep the foot dry and cool. Avoid humid and hot environments. Keep the foot dry and when showering wear a Limbo bag.

To minimise the risk of blood clots please move your foot and ankle at regular intervals. Please ensure you are well hydrated. If you have a risk of blood clots please notify Mr Malik who may organise for you to have blood thinning injections as a precaution.

Two weeks post operatively

You will be reviewed at the clinic and your dressings removed. Your wound will be checked and your toe taped or strapped in a toe splint.

An example of taping around the foot to help maintain surgical correction and allow the foot structures to heal in the correct position

At this stage if the swelling has subsided sufficiently you will be advised to keep your foot in an elevated horizontal position (50-75% of the time). You will require to wear the special post operative shoe for another 4 weeks. Short trips can be made outside, within limits of pain and swelling.

Driving will be permitted for short trips if the left foot has been operated on and you drive an automatic. If the right foot has been operated on it will be at least 8 weeks before any driving is advisable.

Scar desensitisation should start as soon as the wound has completely healed. You can do this by massaging cream (E45 for example) into the scar and around the wound area.

Commence exercises of the lesser toes 3 weeks after surgery and continue for 3 months. These exercises included active resistive and passive toe flexion and extension. They also include intrinsic foot muscle strengthening exercises.

Six weeks post operatively

You will have radiographs taken just before you are seen in clinic. You will go over these with Mr Malik and compare the before and after images. If you have had a bony procedure, it will take a minimum of 6 weeks to heal.

At this stage if your healing is progressing satisfactorily swelling and bruising should have subsided considerably, although expect some degree of swelling for at least 3 to 4 months.

You will be able to start wearing normal footwear (swelling permitted), although stiff soled shoes are advisable. Continue to do the lesser toe exercises for another 6 weeks.

Three months post operatively

Final clinical examination. Discharge if satisfactory.

When can I wear normal shoes?

This depends on your rate of healing and how much pain and swelling you have. For the first 6 weeks we advise you to use the stiff post operative shoe. After 6 weeks it is advised that you wear a stiff soled shoe with a wide toe box while your foot continues to heal.

When can I drive?

Please see guidance above and information here. Ultimately it is the responsibility of the patient to decide if they are safe to drive. A good way of knowing is if you can stamp your right foot heavily on the ground to mimic an emergency brake. If you have any hesitation or pain then it should suggest you are not safe to drive. Remember prolonged driving involves keeping your feet in a dependant position. This will worsen the post operative swelling.

When can I return to work?

This really depends on you and your job. If you have a job that involves a lot of standing, walking and is manual it may be 8 to 12 weeks. If you have a sedentary job, for example in an office and you have a reasonable commute you may be able to go back to work at 2 weeks, although this would be exceptional and not the norm.

What should the final outcome be?

Excellent pain relief and deformity correction. Ability to participate in sports by 6 months. Sometimes up to a year before the foot feels “normal” and fully healed.