Great Toe First Metatarsophalangeal (MTP) Joint Osteochondral Lesion

Summary

The most common cause of chronic pain in the great toe joint is hallux rigidus — essentially arthritis of the big toe joint. Much less common is chronic great toe pain that is caused by a first metatarsophalangeal (MTP) joint osteochondral lesion. Imagine a pristine apple that gets dropped, causing a localized bruise in the apple. This is akin to a first MTP osteochondral lesion. There is a localized area of damage to cartilage on the spherical first metatarsal head while the rest of the cartilage in the great toe joint is intact. Often this condition stems from a trauma such as a badly stubbed great toe.

Symptoms of a Great Toe First MTP Osteochondral Lesion

A first metatarsophalangeal (MTP) joint osteochondral lesion is a relatively uncommon condition characterized by localized pain at the base of the great toe. A previous acute injury to the great toe injury, such as a badly stubbed toe, leading to localized cartilage damage is common. The pain is localized to the base of the great toe (the 1st MTP joint) and swelling of this joint may occur (Figure 1). Episodes of sharp pain with certain movements are common. A sense of catching, clicking, or cracking may also be present along with the pain. Symptoms are usually aggravated by increased movement of the great toe. Pain symptoms are often improved with limiting the motion of the toe such as occurs with the use of stiff-soled comfort shoes.

Physical Exam Findings

There is usually localized discomfort associated with the joint at the base of the great toe (1st MTP joint). Moving this joint will often cause pain in the great toe. Clicking or cracking with movement of this joint may also occur. There may be associated swelling around the joint. Usually the sensation around the toe is intact. Although, some numbness of the great toe may be present if there is noticeable swelling of the joint.

Imaging Studies

Weight bearing x-rays of the foot are important to differentiate a first MTP joint osteochondral lesion from the more common condition of hallux rigidus. Unlike hallux rigidus which will demonstrate joint space narrowing, bone spurs, and arthritic changes — x-rays are often normal in patients with an isolated first MTP joint osteochondral lesion. Although, in some patients, a localized light spot (i.e. a lucency) can be seen in the first metatarsal head.

A definitive diagnosis can usually be made on high-quality MRI, which will illustrate the localized cartilage damage. However, in some patients it can be difficult to differentiate a first MTP osteochondral lesion from mild-moderate osteoarthritis on MRI alone.

Treatment of a Great Toe 1st MTP Joint Osteochondral Lesion

Non-Operative Treatment

Many first MTP osteochondral lesions can be managed successfully without surgery. The discomfort originating from the great toe joint can often be considerably improved, or eliminated, with some simple conservative interventions. Stiff-soled comfort shoes with a wide toolbox can be very effective. By eliminating excess motion through the affected great toe joint pain can usually be settled considerably. Additionally, avoiding certain activities that will tend to exacerbate symptoms will be beneficial. Running, prolonged standing, and activities that require sudden changes in direction or being up on the toes are all likely to aggravate symptoms that stem from a first MTP osteochondral lesion. Anti-inflammatory medication can often help settle symptoms in the short term provided there is no contraindication to these medications. Some individuals may also benefit from a corticosteroid or PRP injection. Although these injections do not address the underlying problem and their effectiveness will usually wear off over time.

Surgical Treatment of great Toe 1st MTP Joint Arthritis

Some individuals with a first MTP osteochondral lesion will require surgery. If conservative treatment is not successful surgery may need to be considered. Also, there are some patients with loose fragments of cartilage that cause painful catching within the joint that will often benefit from surgery. There are two broad categories of surgical treatment for a first MTP osteochondral lesion: a joint cleanup (joint preserving); or a great toe fusion.

A joint cleanup (debridement) may include a number of elements. The great toe joint (1st MTP joint) is opened, and any loose fragments of cartilage are removed as well as any associated bone spurs. The actual first MTP osteochondral lesion may then need to be addressed. This usually involves trimming back any fragments of cartilage associated with the osteochondral lesion to ensure that the remaining cartilage is stably attached to bone. The surgeon may then perform a microfracture by drilling a series of small holes into the area of the bone that is no longer covered with cartilage. This microfracture procedure is performed in an effort to encourage growth of fibrocartilage in this area. Alternatively, other treatment strategies may be used to foster the regrowth of cartilage in this area, or replace the damaged bone and cartilage altogether. Usually, these clean-out surgeries are done through an incision over the top of the great toe. However, in some situations they may be able to be performed arthroscopically.

Fusing the great toe (1st MTP) joint is an effective treatment to address pain and discomfort if the first MTP osteochondral lesion is so large that the joint cannot be saved. This procedure essentially turns a painful stiff great toe into a painless stiff great toe. For more information check out our great toe fusion webpage.

July 11th, 2024