Pain at the back of the heel often signals the presence of a bony overgrowth on the heel bone. This condition is commonly known as a heel spur. While many people are familiar with the type that occurs on the bottom of the foot, a distinct form develops at the rear of the heel bone: the posterior calcaneal spur. This spur is a calcium deposit that forms over time in response to chronic strain. Understanding the location and mechanisms behind this bony protrusion is the first step toward effective management, as it presents unique challenges due to its close relationship with the Achilles tendon.
Defining the Posterior Calcaneal Spur
A posterior calcaneal spur is a bony projection that forms on the dorsal, or rear, surface of the calcaneus (heel bone). This overgrowth occurs specifically at the insertion point where the Achilles tendon attaches to the bone. It is an exostosis, a benign formation of new bone on the surface of an existing bone. It differs significantly from the more common inferior (plantar) heel spur found on the sole of the foot.
The posterior spur is frequently associated with insertional Achilles tendinopathy, which involves chronic inflammation and degeneration at the tendon’s attachment site. It can also be a component of Haglund’s deformity, often nicknamed “pump bump,” which is an enlargement of the heel bone’s upper back corner. The spur can cause mechanical irritation to the overlying soft tissues and may be palpable beneath the skin. Pain is often caused not just by the spur itself, but by the associated inflammation of the Achilles tendon and the retrocalcaneal bursa, a fluid-filled sac situated between the tendon and the bone.
Factors Contributing to Spur Development
The primary mechanism that drives the formation of a posterior calcaneal spur is the body’s response to chronic, excessive mechanical tension on the heel bone. This constant pulling, known as the traction theory, triggers the bone to lay down new calcium deposits to reinforce the strained attachment point. Over time, these deposits harden and project outward, creating the spur.
A tight Achilles tendon is a major contributing factor, applying significant, repetitive strain to its insertion site during activities like walking and running. Biomechanical issues, such as excessive pronation or a high arch, also increase strain on the tendon. Repetitive microtrauma from high-impact activities or intense physical training further exacerbates this chronic irritation.
External factors, particularly footwear with rigid backs that rub or press against the heel, can irritate the tissues, leading to inflammation and accelerating the bony remodeling process.
Conservative Management Strategies
Conservative treatment is the initial and preferred approach, aiming to relieve pain and inflammation through non-invasive means. Initial management involves rest, icing the area to minimize swelling, and the use of non-steroidal anti-inflammatory drugs (NSAIDs) to control pain and tissue irritation. These steps are crucial for calming the acute inflammatory response in the surrounding tendon and bursa.
Physical therapy focuses on progressive loading exercises for the Achilles tendon and calf muscles to improve strength and flexibility. Traditional eccentric exercises must be cautiously applied in this insertional tendinopathy, as they can increase compressive force on the spur and potentially worsen pain. Stretching protocols should be gentle, focusing on maintaining calf muscle length without aggressively pushing the ankle into dorsiflexion, which might aggravate the spur.
Shoe Modifications and Devices
Shoe modifications are an important element, including wearing open-backed shoes to eliminate external pressure and friction on the bony prominence. Heel lifts, inserted into both shoes, are often prescribed to slightly elevate the heel and place the Achilles tendon in a less stretched position, reducing mechanical tension. Night splints are also beneficial, holding the foot in a neutral position during sleep to prevent sharp pain upon waking. Corticosteroid injections are generally avoided in this area due to the risk of tendon weakening and potential rupture when injected directly into the Achilles tendon.
Surgical Considerations and Post-Procedure Care
Surgery is reserved as a last resort when conservative treatments have failed to provide relief after six to twelve months. The primary surgical procedure is a calcaneal ostectomy, which involves carefully removing the bony spur and inflamed tissue, such as the retrocalcaneal bursa. If the spur is large or has significantly damaged the tendon, the surgeon may need to partially detach the Achilles tendon from the heel bone to access and remove the spur, followed by reattachment.
Recovery and Rehabilitation
The recovery period is extended due to the limited blood supply to the Achilles tendon, which slows healing. Patients typically spend the first two weeks completely non-weight-bearing in a splint or cast to protect the surgical repair. Following this initial protective phase, patients transition to a walking boot with heel wedges, and partial weight-bearing is gradually introduced over the next four to six weeks.
Formal physical therapy is mandatory and begins shortly after immobilization, focusing on restoring range of motion and progressive strengthening. Patients must strictly avoid aggressive stretching, particularly eccentric loading, for several months to prevent re-injury or rupture of the reattached tendon. Full recovery and a return to high-impact activities is a long process, often taking between six and twelve months.