What is a plantar plate injury?
The plantar plate is a small but important stabilising ligament at the bottom of the toe joints. Plantar plate injuries are underdiagnosed and often mistaken for other causes of forefoot pain (metatarsalgia), like Morton’s neuroma.
What is the plantar plate?
The plantar plate is a special small cartilage-type tissue located at the deep aspect of the toe joints (also called the metatarsophalangeal or MTP joints). It forms a part of the joint capsule and plays an important role in toes and foot stability.
What are the causes of a plantar plate injury?
The causes of plantar plate injury include:
Activities that put extra stress on the MTP joints and the plantar plate, causing forefoot dorsiflexion (as shown in the picture below). These include activities like running and jumping.
Certain foot mechanical changes, for example, hallux valgus, can put extra stress upon the MTP joints and predispose to plantar plate injury.
How do I know if I have a plantar plate injury?
There is an increase in the pickup rate of plantar plate injury, mainly due to increase awareness of this diagnosis and advancement in imaging techniques. Plantar plate injury is typically an overuse type of injury, and patients often present with gradually progressing pain around the MTP joint. Sometimes this is associated with swelling. The 2nd toe MTP joint is the most affected.
What are the symptoms of a plantar plate injury?
The typical presentation is with a deep ache or pain centred at the involved joint. This can be associated with swelling or bruising of the area.
A certain trauma could trigger the symptoms, but this is not always the case, as plantar plate injuries are commonly due to chronic overuse.
The pain is usually increased by any activity that stresses the joint and forefoot. High heels will also worsen the pain by putting extra pressure on the forefoot.
What condition can mimic a plantar plate injury?
Plantar plate injury vs Morton’s neuroma
This is the main differential diagnosis we see in our practice. A Morton’s neuroma can present with similar symptoms of gradual forefoot pain and swelling. The pain in Morton’s neuroma is typically nerve-type, usually described between the toes. Morton’s neuroma is more common within the 3rd webspace, between the 3rd and 4th metatarsal heads. Imaging assessment is very useful in establishing the diagnosis. A Morton’s neuroma usually results in a centric swelling (centrally located between the toes), while plantar plate injury usually results in eccentric changes closely related to the plantar plate. In the case of plantar plate tears, Ultrasound and MRI are very useful in assessing the exact site and degree of injury.
How to diagnose a plantar plate injury?
You need a clinical assessment by a specialist. This could be an experienced podiatrist, physiotherapist or foot and ankle surgeon. They will take a thorough history and examine the area.
Imaging can be very helpful in confirming the diagnosis. Either an ultrasound or an MR examination is usually performed to assess for this. Ultrasound is easily available and allows a dynamic assessment, i.e., directly inspecting the plantar plate during toe movements. As such, it can provide valuable information about the injury. However, ultrasound is very operator-dependent, so the interpretation of the findings can vary depending on the doctor's experience. MRI, on the other hand, can provide excellent details of the plantar plate and the whole joint if it is done using a dedicated coil to provide detailed small-field images of the forefoot and MTP joints. It is less readily available than ultrasound and will require you to stay still for around 20 minutes to get good images.
Weight-bearing Foot X-rays can also be helpful in assessing joint alignment. There could be an element of MTP joint subluxation in plantar plate injuries. The X-rays will also provide information about the general state of the joints and bones.
What is the treatment for plantar plate injury?
The treatment for plantar plate injuries usually includes:
Supportive measures to reduce the pressure over the forefoot and allow for plantar plate healing. These include avoiding walking barefoot and activity modification. A podiatrist can advise you on shoe adjustments to ensure adequate support to the MTP joints and avoid high-heel shoes, as these usually increase the stress upon the plantar plate.
A physiotherapist can help with a strengthening exercise program and address any tightness in the calf muscles. This can also increase the load upon the plantar plates. Also, special MTP joint strapping is usually useful to support the plantar plate.
Can ultrasound-guided steroid injections help with plantar plate injury?
A steroid injection is not routinely used in plantar plate injuries. There is evidence that a steroid injection into the injured plantar plate can interfere with the plantar plate healing. However, an intra-articular steroid injection can sometimes be considered in cases where there is a previous injury of the plantar plate that has healed with no evidence of instability but with residual joint pain or synovitis. Such cases need to be assessed by a specialist foot and ankle surgeon prior to the referral.
Surgical treatment can be considered if the above measures are not helping. This is best discussed with a specialist foot and ankle surgeon.
Foot & Ankle conditions and treatments