Tarsometatarsal arthritis is a degenerative condition affecting one or more of the small joints in the middle of the foot (midfoot). It usually affects older patients. However, with a history of prior trauma or inflammatory arthropathies (such as Rheumatoid Arthritis), younger patients can be affected as well. It can cause a variety of clinical symptoms from mild discomfort to severe, disabling pain with each step.
There are five tarsometatarsal (TMT) joints in the foot. These are divided into three columns. The medial column is formed by the 1st metatarsal bone and the medial cuneiform. The middle column is formed by the 2nd and 3rd metatarsals aligning with the middle and lateral cuneiforms respectively. The lateral column is formed by the 4th and 5th metatarsals and the cuboid. While these joints do not have the extensive range of motion which is present in other joints, they nevertheless can be a source of pain when degeneration of the cartilage is present.
With each step of walking the TMT joints are active and loaded. With normal gait, transfer of weight from the heel to the toes allows the feet to propel the body forward on the ground. This load transfer is predicated on having a stable lever in the foot. This stable lever is formed by the medial and middle (first three) TMT joints since they have considerably less inherent motion then the 4th and 5th TMT joints. The latter two TMT joints allow for push off and adaptation walking on uneven ground.
The most common cause of TMT arthritis is from prior trauma. This can be a Lisfranc injury where the ligaments supporting the TMT joins are ruptured resulting in instability and/or change in contact pressures across the joint even after surgery to stabilize the joint. Other examples of trauma include fractures at the base of the metatarsals which extend into the TMT joints and sprains or other twisting injuries resulting in occult cartilage damage initiating cartilage wear. Non-traumatic causes of TMT arthritis are also present. An acquired flatfoot deformity, when present for a prolonged period of time, can sometimes result in arthritis at the tarsometatarsal joints. A specific type of Charcot arthropathy can result in joint destruction and subsequent arthritis in the TMT joints. Systemic inflammatory arthropathies such as Rheumatoid Arthritis can affect the TMT joints as well.
The typical patient will complain of a dull pain or discomfort of varying intensity in the dorsal midfoot which is present with walking and weight-bearing activities and is relieved with rest. Symptoms usually have an insidious onset with no history of a recent acute, inciting injury. Often, pain may have been present for several weeks prior to the patient seeking any medical attention for the issue. Patients may also present with a primary complaint of a painful bony prominence on the dorsal midfoot causing pain with compression from shoewear. In severe cases, there may be complaints of foot deformity with a history of progressive loss of arch.
Treatment of TMT arthritis begins with non-operative measures. Non-steroidal antiinflammatory (NSAID) medications are a first-line treatment with the goal of alleviating the associated midfoot pain. These medications do have the potential of adverse effects in the gastrointestinal and/or renal systems with long term use. The other standard non-operative treatment option is the use of stiff shoes with a rocker bottom modification. This can be accomplished by placing a carbon fiber insole orthotic in the shoe, therefore effectively stiffening the shoe. Taken in concert with the rocker-bottom sole, it provides a means for bypassing the typical TMT joint motion and loading which occurs with each step during gait. Selective steroid injections into the affected TMT joints are another non-operative treatment option. However, their efficacy and effectiveness specific to TMT arthritis has not been extensively studied.
When the patient does not have significant relief with non-operative treatments or use is not well-tolerated, operative treatment is offered. For arthritis involving the first three TMT joints, operative treatment is a selective midfoot fusion (arthrodesis). This surgery consists of fusing of all the involved TMT joints and intercuneiform joints and possibly the naviculocunieform joints. Postoperatively, the patient may not be allowed to fully weightbearing on the foot for several weeks depending on the specific protocol used. For lateral column TMT arthritis, surgical treatment options are not as clear. There is considerable opinion that motion sparing procedures (e.g. joint resection with tendon interposition) are preferable because the 4th and 5th TMT joins are comparatively more mobile with regular gait than the medial and middle columns. Therefore, any arthrodesis involving these joints would have potential for deleterious functional outcomes and pain in other areas of the foot. However, there have been studies showing good results with arthrodesis of the lateral column TMT joints.
Written by Sudhir Belagaje, MD Reviewed by Tye Ouzounian, MD Last reviewed June 2015