The term metatarsalgia translates to “pain in the metatarsals”. It is most commonly used to describe pain in the metatarsal heads, at or near the ball of the foot. Though it is sometimes used as a discrete diagnosis, the term metatarsalgia is a very general term that does not offer a reason for the pain. There are a number of different conditions that can cause metatarsalgia, and many others that may mimic the findings.
True metatarsalgia results from increased pressure in the metatarsal heads. This is most commonly the result of biomechanical deformities such as hallux valgus or an elevated first ray. Conditions like this may also be associated with bunion formation. Most frequently it is associated with a flatfoot, or a foot that is prone to pronation syndrome. However, increased pressures through the metatarsal heads may also be seen in a high-arched foot, or pes cavus.
Another common cause of metatarsalgia is a thinning of the fat pads at the bottom of the foot. Fat pads are normally found underneath the heel and at the ball of the foot. These well-organized structures help to cushion the forces applied to the foot while walking. In older people, the fat pads can thin as a normal part of aging, a component of some disease processes, or with the use of some drugs such as oral steroids. When the fat pad at the ball of the foot thins, the cushioning underneath the metatarsal heads is lost, and metatarsalgia may ensue.
Pain in the metatarsal heads is also commonly seen with hammertoes, as the contracted digits force the metatarsal heads into the ground with excessive force. Over time, this can create a painful situation.
Other conditions of the foot may appear as metatarsalgia, but may actually be a different pathological process. Neuromas, particularly those found between the metatarsals such as Morton’s neuroma, can appear at first as metatarsalgia. Stress fractures of the foot may also lead to pain in the ball of the foot or at the metatarsal heads.
Rheumatoid arthritis may appear initially as metatarsalgia, and should be ruled out as a part of the clinical exam. This may include x-rays as a diagnostic study, which can also look for avascular necrosis of the metatarsal heads as a cause of the pain. Tendinitis, bursitis, and capsulitis (a swelling of the joint capsule) can also appear as metatarsalgia. It is up to the clinician evaluating the patient to differentiate between these pathologies.
The best treatment, therefore, for metatarsalgia, is to address the underlying cause of the condition. If it is a biomechanical etiology, such as from over-pronation, conservative therapy may address correcting the deformity. The use of custom orthotics or another type of shoe insert is commonly employed as a first-line treatment. Simply resting and icing the area while taking anti-inflammatory medications may alleviate the pain, but can also delay the proper and necessary treatment. Custom orthotics, specialized shoe inserts, a change in shoes, and possibly shoe modifications will all help the person with a loss of the protective fat pads found on the bottom of the foot as well.