Fat Pad Atrophy of the Foot
One of the complications of Morton’s neuroma surgery and Morton’s neuroma corticosteroid injections is Fat Pad Atrophy. It causes significant foot pain and metatarsalgia.
What is the Pedal Fat pad and what does it do?
The fat pad is the the thick pad of connective tissue that runs under the ball and heel of the foot and forms the lower aspect of foot. The purpose of the fat pad is:
- To provide cushioning to minimize the effect of friction, pressure and gravitational forces on the foot musculature; and,
- To serve as a mechanical anchor that helps in shifting the body weight without overwhelming connective tissue elements.
What is Fat Pad Atrophy?
Fat pad atrophy the gradual loss of the fat pad in the ball or heel of the foot. Conditions like fat pad atrophy of the foot are more common in aging population and usually presents with severe foot pain during walking. Fat Pad atrophy is the thinning of the pad that exposes the delicate connective tissue elements to strain and pressure creating inflammation and micro-injury. In poorly managed cases, patients present with severe pain and discomfort.
Some characteristic symptoms of fat pad atrophy include:
- Pan in the foot (Metatarsalgia) which becomes worse when wearing high heels or walking over a hard flat surface.
- Pain in the foot when a person is in standing position for extended periods of time. (62% of diagnosed sufferers report excessive foot pain after a long walk or long period of standing.)
- Feeling of the development of a mass or swelling in the foot/ heel.
- The ball of foot may become excessively thick due to callus formation.
Who is at risk of getting Fat Pad Atrophy?
The risk profile and prevalence of fat pad atrophy is fairly comparable in males and females. However, some experts believe that females are relatively more vulnerable to develop this condition because of:
- High heels which do not support the bottom of the foot; and,
- Ill-fitting or very tight footgear which aggravates the risk of injuries such as callus formation. If left untreated, such injuries can lead to various degenerative foot changes.
Certain factors that may aggravate the risk of developing Fat Pad Atrophy such as:
- Age: The risk of developing degenerative foot conditions increases with progressing age. With increasing age new cartilage and fat tissue formation decreases which makes the bones weaker and more prone to damage. (By our mid-30’s, foot fat pads begin to deteriorate or thin. Sometimes, the thinning doesn’t happen evenly. By our 50’s, some people lose as much as half of the fat that normally pads and protects the ball and heel area of the foot. By our 70’s, the fat pads can be quite thin.)
- Collapsed bone: Degeneration or damage to the long bones of the foot can exert significant pressure over the fat pad leading to increased wear and tear damage..
- Footwear: As discussed previously, the footwear selection can cause as well as aggravate the risk of foot pad atrophy.
- High arch: Certain anatomical characteristics, such as high pedal arches can also cause changes in the foot pad by applying direct pressure on the connective tissue architecture.
- Injury: Injuries caused by significant trauma such as an accident, or other forms of trauma which leads to multiple fractures or surgeries can also increase the risk of developing fat pad atrophy
- Family history: Family history or genetics plays a very important role in development of atrophic and degenerative conditions.
- Arthritis: Inflammation of joints especially in the setting of rheumatoid arthritis aggravates the risk of fat pad atrophy as the bones becomes more vulnerable to damage as a result of ongoing inflammation
- Diabetes: Individuals with persistently high blood sugar levels are vulnerable to develop neuropathy (which leads to numbness and loss of sensation in the foot). The chances of developing pressure-induced atrophic changes increases resulting in fat pad atrophy.
- Steroid Injections: Steroid injections in the foot, especially if done too frequently can cause fat pad atrophy.
- Medications: Chronic use of steroids is also known to cause fat pad atrophy in adults.
Treatment of Fat Pad Atrophy:
- Avoid activities which puts too much pressure on the foot such as walking on hard, flat or uneven surfaces.
- Avoid wearing high heel and switch to comfortable footwear.
- Opt instead for low impact weight bearing exercises to optimize healing and regeneration processes.
- Use paddings or insoles to allow even distribution of weight to minimize the direct impact of pressure.
- Chose footwear that supports the foot (especially the heel and arches) to provide cushioning and shock absorbing.
- Regenerative medicine is a new field that shows significant potential in the treatment of fat pad Atrophy, especially Platelet Rich Plasma injections.
When conventional methods fail, healthcare providers may recommend surgical treatment as a last resort.
- Dalal, S., Widgerow, A. D., & Evans, G. R. (2013). The plantar fat pad and the diabetic foot–a review. International wound journal.
- Taneja, A. K., & Santos, D. C. (2014). Steroid-induced Kager’s fat pad atrophy. Skeletal radiology, 43(8), 1161-1164.
- Molligan, J., Schon, L., & Zhang, Z. (2013). A stereologic study of the plantar fat pad in young and aged rats. Journal of anatomy, 223(5), 537-545.
- Prado, M. P., Fernandes, T. D., Mendes, A. A. M., & Amodio, D. T. (2012). Surgical Stabilization of Calcaneal Fat Pad for Treatment of Structural Insufficiency and Instability. Foot & ankle international, 33(4), 340-343.