Lesser MTP Joint Arthritis Leading to Metatarsalgia
Background
Arthritis at the base of one or more of the lesser toes is a relatively uncommon cause of forefoot pain (metatarsalgia). Much more commonly pain in this area is due to inflammation of the metatarsophalangeal (MTP) joint from classic overload metatarsalgia. However, in some patients loss of the gliding cartilage in one or more of the MTP joints will cause forefoot pain and swelling. The loss of cartilage covering the metatarsal head is the most common cause. Often there will be a previous history of localized trauma or the development of Freiberg’s disease at a younger age. Patients with advanced rheumatoid arthritis may also suffer cartilage loss in the MTP joints.
Signs and Symptoms
Pain and swelling in the forefoot are the classic symptoms of lesser toe MTP joint arthritis. These are often similar or identical to the symptoms of classic metatarsalgia. However, classic metatarsalgia is much more common than lesser MTP arthritis! Symptoms are usually made worse with prolonged standing, walking, or running. The pain and swelling may be improved with use of an anti-inflammatory medication, limiting activities, and the use of a stiff soled comfort shoe. In addition, there is often restricted motion of the joint at the base of the affected toe. Pressing on this area will often increase the discomfort.
Imaging Studies
Weight-bearing plain x-rays of the foot will identify arthritic changes associated with the affected MTP joint. These x-ray changes include loss of the joint space, irregularity of the bone, and bone spurs.
An MRI is usually not indicated unless other diagnoses are being considered. If performed, an MRI will usually show increase fluid in the affected MTP joint, and associated edema within the bone of the metatarsal head.
Treatment
Non-Operative Treatment of Lesser MTP Joint Arthritis
Non-operative treatment can be very helpful in improving the symptoms associated with lesser MTP joint arthritis. Often, the symptoms can be dramatically decreased or even eliminated. However, the baseline damage to the affected joint cannot be undone. Conservative treatment of lesser MTP joint arthritis is similar to the treatment of classic metatarsalgia and includes:
- Activity modification to limit standing, walking and running
- Comfort shoes to decrease the focal load and motion through the affected MTP joint.
- Anti-inflammatory medication to decrease the pain from the associated inflammatory response.
- A corticosteroid injection into the arthritic MTP joint can help to settle the pain response from the arthritis. Although, the improvements from the injection will tend to wear off over time.
Surgical Treatment of Lesser MTP Joint Arthritis
Fortunately, most patients, even those with advanced lesser MTP joint arthritis will not require surgery. However, there is a group of patients with this condition that will have ongoing debilitating symptoms. These patients may benefit from surgery. There are a variety of proposed surgical treatments which highlights that there is no perfect surgery for this condition. Typical surgical treatment may include:
- Cleaning out (debriding) the affected joint. Removing associated bone spurs, cleaning up the joint, and micro fracturing the affected metatarsal head to encourage fibrocartilage growth can be very beneficial in improving a patient’s symptoms. However, this surgery will not restore the joint back to normal.
- Interposition arthroplasty is the placement of soft tissue, usually from the associated joint capsule, into the joint to serve as a buffer between the two bones. This procedure is usually combined with a debridement of the joint.
- The use of a joint spacer. Although experimental, some surgeons have tried placing a joint spacer into the base of the affected metatarsal head. Resection of the affected metatarsal head has been performed for severe cases. This leads to a floppy toe, and may overload the joints on either side of the affected toe. Nevertheless, it may help relieve the associated joint pain.
September 30th, 2024