A bone spur, medically known as an osteophyte, is an extra growth of bone tissue that typically forms near a joint where bones meet. These bony projections are the body’s natural attempt to stabilize an area under chronic stress or damage, often due to arthritis. While bone spurs are often associated with the heel or spine, they can definitively form on the top of the foot. These growths are common, especially as the body ages, and can range from being unnoticeable to causing significant discomfort.
The Specifics of Bone Spurs on the Top of the Foot
A bone spur on the top, or dorsal aspect, of the foot may have specific names depending on its location. When located around the midfoot, it is frequently called a Tarsal Boss or a dorsal exostosis. This prominence most often occurs at the first, second, or third tarsometatarsal joints, which are small joints in the middle of the foot.
The spur is an outgrowth of bone, often indicating wear and tear in these joints. Another common location is the first metatarsophalangeal joint, where the big toe connects to the foot. The physical bump created by this extra bone growth causes symptoms when it interacts with footwear or surrounding soft tissue.
Underlying Causes of Formation
Bone spurs develop as a biological response to long-term irritation or mechanical stress placed upon the joints and bones. The most frequent systemic cause is osteoarthritis, where the protective cartilage between bones deteriorates over time. In an attempt to repair the damage, the body produces extra bone tissue at the joint margins.
Chronic biomechanical issues are another major contributor, particularly abnormal distribution of pressure across the foot. Conditions such as flat feet (overpronation) or high arches (underpronation) place uneven loads on the joints. This irregular stress leads to continuous friction between the bones, prompting the development of a spur.
Past injuries to the foot, including severe sprains or fractures, can destabilize a joint and trigger the body’s protective bone growth mechanism. Continuous pressure from external factors, like wearing tight-fitting shoes or restrictive laces, creates friction over the delicate joints on the top of the foot. This repetitive microtrauma can lead to the formation of the extra bony growth directly beneath the point of contact.
Recognizing the Signs and Symptoms
Some bone spurs cause no problems and are only discovered incidentally on X-rays, but many others become symptomatic due to their location on the top of the foot. The most direct sign is a noticeable, hard, bony lump or prominence on the foot’s surface. This bump is often tender to the touch because it presses against the skin and soft tissues.
Pain typically worsens with activity, especially movements that require pushing off the foot, such as walking or running. A specific source of pain is the friction and pressure caused by wearing shoes, particularly those with a restrictive toe box or a tongue that presses down on the growth.
The constant irritation from footwear can also lead to localized redness, swelling, or the formation of a callus or bursa over the bump. Stiffness or a restricted range of motion in the adjacent joint may also occur as the spur physically blocks normal joint movement.
Management and Treatment Options
Diagnosis of a bone spur on the top of the foot is confirmed through a physical examination, where the hard prominence is felt, and then validated with X-ray imaging. The X-ray provides a clear visual of the bony growth and its exact location relative to the joints. Treatment aims to alleviate the symptoms, as the bone spur itself cannot be dissolved or removed without surgery.
Conservative Management
Initial management focuses on non-surgical methods, starting with modifications to footwear. Wearing shoes with a wider and deeper toe box, or using padding to cushion the area over the spur, can significantly reduce painful pressure. Non-steroidal anti-inflammatory drugs (NSAIDs) are often used to manage inflammation and pain around the affected area.
Custom orthotics or arch supports can be beneficial by correcting underlying biomechanical issues to redistribute pressure more evenly across the foot. If inflammation is severe, a corticosteroid injection may be administered directly into the area to provide localized relief, although this does not shrink the bone spur. These conservative approaches are successful for most patients and are the first line of defense.
Surgical Intervention
Surgery is considered a last resort, reserved for cases where the pain is severe, conservative treatments have failed, or the spur significantly impairs mobility or the ability to wear shoes. The procedure to remove the spur is called a dorsal exostectomy, which involves surgically shaving down the excess bone tissue. The necessity of surgery is determined by the degree of functional impairment and persistent pain.