Fibrous tissue and ligaments surrounding the joint at the base of a toe or toes form a “capsule” around the joint. This capsule helps stabilize the joint allowing it to function properly and stay in alignment. Capsulitis is when these ligaments and the joint capsule have become irritated, inflamed/swollen causing discomfort and sometimes, movement or dislocation of the toe.
Although toe capsulitis can occur in any toe or foot joint, it commonly affects the second toe. This irritation and inflammation/swelling can causes considerable discomfort and, if left untreated, can eventually lead to weakening of the surrounding ligaments within the capsule. Eventually, this can cause permanent pain, positional change, deformity, and/or dislocation of the toe. Capsulitis—also referred to as “predislocation syndrome”—is a very common condition that can occur at any age.
Causes
Capsulitis stems from is a result of abnormal foot mechanics, where the ball of the foot beneath the toe joint takes an excessive amount of weight-bearing pressure.
Certain conditions or characteristics can make a person prone to experiencing excessive pressure on the ball of the foot leading to capsulitis. These most commonly include a bunion deformity, a 1st big toe joint that lacks motion, a metatarsal bone longer than the first metatarsal bone, an arch that has laxity therefore considered unstable, and/or a tight calf muscle.
Symptoms
Because capsulitis is a progressive disorder and usually worsens if left untreated, early recognition and treatment is vital. In the earlier stages—the best time to seek treatment—the symptoms may include:
- Pain, particularly on the ball of the foot. It can feel like there’s a marble in the shoe or your sock is bunched up under the ball of the foot
- Swelling in the area of pain, including the base of the toe on top or the bottom of the foot
- Difficulty wearing shoes
- Pain when walking barefoot
- A callus may be present on the ball of the foot where the pain is present
In more advanced stages, the supportive ligaments within the joint capsule weaken leading to failure of the joint to stabilize the toe. The unstable toe drifts toward a neighboring toe and eventually crosses over or under this neighbor toe. This deformity is called “overlapping toe” or “cross-over toe” and is the advanced or end-stage of capsulitis. It is a permanent deformity that can only be surgically treated. The time it takes to reach the end-stage of capsulitis is different for every patient. It can be a gradual progression over months to years or quicker due to trauma or excessive steroid injections in the area.
Diagnosis
An accurate diagnosis is essential because the symptoms of capsulitis can be similar to those of stress fractures, fractures, osteochondritis (trauma-induced decreased blood supply to the bone), neuroma/neuritis (nerve lining inflammation), or metatarsalgia (mechanical pressure across the ball of the foot).
