Capsulitis is inflammation of a joint capsule. Ligaments surround your joints, including your toe joints, and help form a capsule. Joint capsules help your joints function properly. Capsulitis is a common problem in certain parts of your body, especially your shoulders and toes. Capsulitis-related inflammation may cause significant discomfort. This health problem can, over time, lead to toe dislocation if it not treated properly. In fact, capsulitis is sometimes known as pre-dislocation syndrome. Capsulitis is a condition that can manifest in people of all ages.
Certain parts of your feet and toes may be more likely to develop capsulitis than others. One of the capsules that most commonly experiences this ligamentous inflammation are the capsules surrounding your metatarsophalangeal, or MTP, joints at the ball of your foot. Each foot possesses five MTP joints that connect your toe bones, or phalanges, with your metatarsal bones—long, thin bones located in your mid-foot.
The most common MTP joint capsule to develop capsulitis is the one that connects your second metatarsal bone with your second set of phalanges. Problems with this capsule, especially inflammation, are particularly common, due to excessive pressure placed on this joint during weight-bearing activities. Capsulitis may be difficult to diagnose because of the tendency for other structures in your forefoot to also become inflamed from biomechanical problems.
Causes and Symptoms
Most foot health experts believe that capsulitis is caused by aberrant, or unusual, foot mechanics that involve excessive weight-bearing on the ball of your foot, beneath your affected toe joint. Certain factors may increase your likelihood of developing this problematic condition, including:
- Extreme bunion deformity
- A second toe that is longer than your first toe
- An unstable foot arch
- Tight calf muscles on your involved side
- Imbalance between the muscles on top of and below your feet (extensors and flexors)
- Regular use of footwear with an elevated heel and/or toe spring
Conventional footwear may be the most common cause of capsulitis. Most shoes possess elevated toe boxes, or toe spring, as a built-in design feature. Toe box elevation increases pressure under the capsules of your MTP joints. Because your second metatarsal bone is usually the longest in your foot, it performs more than its normal share of weight bearing, and it can become inflamed and painful. Tapering toe boxes—another problematic design feature built into most conventional footwear—is another factor contributing to capsulitis. Tapering toe boxes force your big toe toward your second toe, putting your big toe out of balance with its corresponding metatarsal bone.
Several distinct signs and symptoms commonly develop in people who have capsulitis, including:
- Pain in your affected area
- Swelling around your involved joint capsule
- Redness of the skin overlying your affected joint
- The sensation that you are walking on a stone
Painful calluses may form in some individuals if capsulitis becomes a chronic health problem. A person who develops calluses may feel as though the callus has a core or seed inside of it. These calluses are commonly misdiagnosed as plantar warts, and they can occur under any of your metatarsal heads. Capsulitis-induced calluses usually respond to metatarsal pads and cutouts. Cutouts are an orthotic technique that allows your more prominent metatarsal head—one of the structures most commonly affected by capsulitis—to drop lower than your other metatarsal bones. This action helps balance your weight-bearing load and decreases the pressure on your affected area.
Some people with this condition also experience nerve symptoms caused by capsulitis-related swelling. Bursitis—inflammation of fluid-filled sacs located in your forefoot—is another health problem that may be associated with capsulitis or confused with this condition.
Capsulitis often responds to conservative, non-surgical treatments. This condition is best treated in its early stages to help improve your affected joint’s stability, reduce your pain and other symptoms, and resolve the root cause of your problem. Common treatment strategies for this health problem include:
- Rest: Reducing weight-bearing activities can help control your symptoms.
- Ice: Icing your affected area can minimize your pain and swelling.
- Taping or splinting: Taping helps align your involved toe and prevents your toe from drifting.
- Stretching: Stretching may be particularly important for those who have tight calf muscles or a foot extensor/flexor imbalance.
- Shoe therapy: Shoes with little or no toe spring and wide toe boxes may be most helpful, as they help take focal pressure off the ball of your foot.
- Pads and toe spacers: Metatarsal pads placed in your shoe can help return your foot’s fat pad to its rightful, protective location under your metatarsal heads. Correct Toes is another helpful treatment tool for capsulitis, as it encourages proper alignment of your metatarsal bones and forefoot structures.
- Anti-inflammatory agents: Supplements or medications can help reduce your pain and swelling.