THE ARTHRITIC BIG TOE

THE ARTHRITIC BIG TOE

Many people take their big toe … called hallux in medical parlance, for granted. It is not intuitive that this structure of the foot is significant to how we walk and the amount of pain we may feel during walking. One of the most common problems with the big toe is hallux limitus. This deformity is defined as less than 65 degrees of dorsiflexion (flexing the toe upwards) at the joint between the metatarsal bone and the phalanx bone. Hallux limitus should be addressed immediately because it often develops into hallux rigidus, which is defined as less than 20 degrees dorsiflexion due to degeneration at the metatarsophalangeal joint. Decreased range of motion of the hallux particularly comes into play during propulsion, or when the foot leaves the ground while walking. Often hallux limitus or rigidus is seen with age, arthritis, and ‘wear and tear’, in many athletes and in contact sports such as soccer. It is painful due to the lack of motion or ‘push off’ when one moves forward in the gait (walking) cycle.


There are several causes of hallux limitus. For instance, a structurally long first metatarsal can cause jamming at the joint during propulsion. Furthermore, a common foot deformity called rearfoot varus, or when one walks too much on the outside part of the heel, causes limitus of the big toe if there is compensation present. This means that the person tries to walk more efficiently by putting more pressure on the inside of the heel. Although this seems beneficial, the compensatory movement leads to extra mobility and often elevation of the first metatarsal during propulsion, which consequently leads to limited dorsiflexion at the joint.


A popular conservative treatment for hallux limitus is an orthotic (custom arch insert) with a modification called Morton’s Extension. This modification is used to improve metatarsal function. If this bone is structurally elevated, the orthotic essentially raises the ground up to the bone in order to prevent the compensation toward the inside of the foot and jamming at the metatarsophalangeal joint. In other words, it reduces the excursion of the bone.


Many other treatments exist, such as: massage, linaments, stretching, physical therapy, ‘toe raise’ exercises, and gentle range-of-motion exercises which can be done at home. In addition, stretching before sports or a long walk can be beneficial. When conservative measures fail, surgery may be indicated. Since there is no ‘perfect’ solution, many procedures exist, some based on age, and others based on activities. These range from a ‘decompressive bunionectomy’ to a joint resection (Keller arthroplasty), to replacing the joint with an artificial joint (total joint replacement) to fusion of the joint to maintain length and reduce pain. A new technique we are using is a decompressive osteotomy that shortens the bone and increases the joint space – this improves range of motion while keeping the joint intact.

Adapted from Schoenhaus, Harold; Whitney, Kendrick.