Plantar plate tears and ball-of-foot pain (metatarsalgia)

What is a plantar plate tear?

Each of the four lesser toes joins the foot at a metatarsophalangeal (MTP) joint, at the ball of the foot. Under each joint lies the plantar plate, a tough fibrocartilage band that holds the joint steady and takes load when you push off.^[1] Repeated overload can stretch it, and it can eventually tear. Once the plantar plate fails, the toe can drift sideways, rise up or stiffen, and the joint can become painful and unstable. Without treatment the changes can become a fixed deformity, such as a hammertoe.^[3,2] See hammertoes.

Plantar plate tears are one cause of metatarsalgia, the general term for pain in the ball of the foot. This pain is felt across the sole behind the second to fourth toes, and it often occurs together with deformity of the big toe, the little toe or the lesser toes.^[4] See foot pain by location.

Symptoms

• pain under the ball of the foot, behind the toes
• swelling at the base of a toe
• a toe that drifts, lifts or looks bent, as the joint loses its alignment
• a feeling that the toe joint is unstable^[3,4,1,2]

What causes it?

Metatarsalgia has many causes, all related to how the foot is built and how weight is carried during walking. They include foot shape, deformity of the foot and toes, and a tight calf, which is a recognized contributor to pain in the ball of the foot.^[4,5,7] Causes are divided into primary (from the foot’s own structure and mechanics), secondary (from another problem such as a bunion or a previous surgery) and iatrogenic (caused by an earlier treatment).^[5] A big-toe problem such as a bunion or hallux rigidus, a high arch (cavus foot) and a tight calf (see gastrocnemius recession) can all shift load to the ball of the foot.

How it’s evaluated

The evaluation looks at where it hurts and which toe is affected. It checks how stable the joint is with hands-on tests (such as the drawer test, which checks for movement of the toe joint). It also looks at your shoes and gait. These tests depend on the examiner’s skill and aren’t standardized, so imaging often adds important information.^[3] Standing X-rays show the bones, and ultrasound or MRI can show the plantar plate itself; MRI has higher specificity and ultrasound can be done in real time.^[5,3] X-ray and ultrasound are available on site at our practice; see foot and ankle imaging.

Because several conditions cause similar pain, including Morton’s neuroma and joint inflammation, the diagnosis needs a combination of the history, examination and imaging.^[3]

Non-surgical care

First-line care is conservative: stretching exercises, footwear changes and insoles or pads that offload the painful area.^[5,4] For a plantar plate injury, options also include splinting or taping the toe, offloading, and sometimes an injection into the joint. The research is limited to case series, and it suggests that these treatments are less effective once a tear has advanced.^[6]

When surgery is considered

Nonsurgical management is usually enough for metatarsalgia.^[4] Surgery is considered when the toe joint stays painful and unstable despite a well-tried non-surgical program, or when a fixed deformity has developed. Because pain in the ball of the foot often has more than one cause, the plan may include soft-tissue procedures. Examples are calf lengthening, tendon transfer and repair of the plantar plate. Sometimes a shortening cut in a metatarsal (osteotomy) is added.^[5,4]

Direct plantar plate repair reattaches the torn tissue to the base of the toe bone, and it has become the preferred approach for many foot surgeons.^[1,2] A pooled analysis of 12 studies with 537 tears found that pain and function scores improved substantially after repair, mostly through a cut on the top of the foot.^[2] An earlier systematic review of six case series (162 patients) also reported favorable results but cautioned that the studies were small and limited.^[8]

For the operations, recovery and risks, see hammertoe and lesser-toe surgery, which includes correction of the toe deformity that often goes with a plantar plate tear.

When to seek care

Consider an evaluation if pain in the ball of the foot lasts more than a few weeks. The same goes for a toe that is drifting or lifting, or pain that limits standing and walking.