Exostoses (bone spurs) - Causes, Treatment & When to See a Doctor

What is Exostoses (bone spurs)?

Exostoses, more commonly known as bone spurs, are abnormal bony projections that develop on the surface of a bone. They most often arise where tendons or ligaments attach to bone (entheses) and can occur in any part of the skeleton, but are most frequent in the spine, shoulders, hips, knees, elbows, and feet. While a single spur may be asymptomatic, multiple or large spurs can impinge on nerves, muscles, or joints, leading to pain, reduced range of motion, and functional limitation.

The term “exostosis” comes from the Greek words exo (outside) and osteon (bone). In most medical literature, “bone spur” is used interchangeably with “osteophyte.” These growths are typically composed of mature lamellar bone and develop slowly over months to years.

Common Causes

Bone spurs are rarely the result of a single factor; they usually reflect an interaction of mechanical stress, aging, and underlying disease. Below are the most frequently identified contributors:

• Osteoarthritis – Degenerative joint disease leads to cartilage loss, prompting the body to lay down extra bone in an attempt to stabilize the joint.
• Degenerative disc disease – Wear‑and‑tear of intervertebral discs can cause the vertebrae to develop osteophytes.
• Spinal spondylosis – Age‑related degenerative changes in the spine commonly produce bone spurs that narrow the spinal canal.
• Traumatic injury – Fractures or repeated micro‑trauma can stimulate bone healing responses that result in exostoses.
• Enthesopathy (e.g., plantar fasciitis) – Chronic stress at tendon‑bone attachments can trigger spur formation.
• Genetic conditions – Hereditary multiple exostoses (also called osteochondromatosis) is an inherited disorder characterized by numerous bony outgrowths.
• Infection – Chronic osteomyelitis may lead to reactive bone formation.
• Metabolic disorders – Conditions such as hyperparathyroidism or diffuse idiopathic skeletal hyperostosis (DISH) increase bone turnover.
• Obesity – Excess body weight places additional load on weight‑bearing joints, accelerating spur development.
• Age – The prevalence of osteophytes rises sharply after age 40, reflecting cumulative wear and reduced regenerative capacity.

Associated Symptoms

Many people with bone spurs never notice them. When symptoms do arise, they are usually related to the spur’s location and the structures it irritates:

• Pain that worsens with activity and eases with rest.
• Stiffness, especially after periods of inactivity (morning or prolonged sitting).
• Localized tenderness to palpation.
• Limited range of motion in the affected joint.
• Clicking, grinding, or popping sensations (crepitus) during joint movement.
• Numbness, tingling, or weakness if a spur compresses a nerve (e.g., cervical osteophytes causing radiculopathy).
• Swelling or inflammation of nearby tendons or bursae (e.g., heel spur with plantar fasciitis).
• Visible deformity in severe cases, such as a bony lump on the heel or scapula.

When to See a Doctor

Most bone spurs can be managed conservatively, but certain situations warrant medical evaluation:

• Persistent pain that interferes with daily activities or sleep.
• Progressive loss of joint motion or strength.
• Numbness, tingling, or burning sensations radiating down an arm or leg.
• Any sign of infection – redness, warmth, fever, or drainage from a wound over a spur.
• Sudden worsening after a fall or trauma.
• Visible swelling or a rapidly growing lump.

Early assessment helps prevent complications such as nerve compression, joint instability, or chronic disability.

Diagnosis

Diagnosing exostoses involves a combination of patient history, physical examination, and imaging studies.

1. Clinical Evaluation

• Detailed history of symptom onset, aggravating/relieving factors, and previous injuries.
• Inspection for visible deformities or asymmetry.
• Palpation to locate tender bony prominences.
• Range‑of‑motion testing and neurological exam when nerve involvement is suspected.

2. Imaging

• Plain X‑ray – First‑line test; clearly shows bony outgrowths and assesses accompanying joint degeneration.
• CT scan – Provides three‑dimensional detail, especially useful for spinal or complex anatomical regions.
• MRI – Highlights soft‑tissue involvement, nerve compression, and inflammation around the spur.
• Ultrasound – Helpful for superficial spurs (e.g., heel) and for guiding injections.

3. Laboratory Tests (when indicated)

• Complete blood count and inflammatory markers (ESR, CRP) if infection or inflammatory arthritis is a concern.
• Serum calcium, phosphate, and parathyroid hormone levels for metabolic bone disease work‑up.

Treatment Options

Management is individualized based on spur size, location, severity of symptoms, and patient goals. Most treatment plans begin conservatively.

Non‑Surgical (First‑Line) Therapies

• Activity modification – Avoid movements that provoke pain; incorporate low‑impact exercises (swimming, cycling).
• Physical therapy – Targeted stretching, strengthening, and manual techniques improve joint mechanics and reduce stress on spurs.
• Analgesics – Acetaminophen or NSAIDs (ibuprofen, naproxen) for pain and inflammation (use per FDA guidelines).
• Topical agents – Capsaicin or NSAID creams may provide localized relief.
• Corticosteroid injections – Delivered into adjacent bursae or joints to reduce inflammation; ultrasound guidance improves accuracy.
• Orthotics & footwear – Heel cups, arch supports, or custom shoe inserts relieve pressure on foot spurs.
• Heat/Cold therapy – Alternating modalities can decrease muscle spasm and swelling.
• Weight management – Reducing excess body weight lowers mechanical load on joints, slowing further spur formation.

When Surgery Is Considered

Surgical removal (exostectomy) is reserved for:

• Severe, refractory pain despite ≥6 months of conservative care.
• Documented nerve or vascular compression (e.g., cervical radiculopathy, peripheral neuropathy).
• Functional impairment that limits essential activities or work.
• Rapidly enlarging spurs with suspicion of malignant transformation (rare, but possible in hereditary multiple exostoses).

Procedures may be performed arthroscopically (minimally invasive) or via open surgery, depending on location. Post‑operative rehab is crucial to restore motion and strength.

Adjunctive and Emerging Therapies

• Platelet‑rich plasma (PRP) – Early studies suggest PRP may modulate inflammation around osteophytes.
• Shockwave therapy – Low‑intensity extracorporeal waves have shown benefit for plantar fasciitis‑related heel spurs.
• Biologic agents – Research ongoing into drugs that target bone remodeling pathways (e.g., RANKL inhibitors) for patients with severe DISH.

Prevention Tips

While not all spurs are preventable, lifestyle and medical strategies can reduce risk or slow progression:

• Maintain a healthy weight – Aim for a BMI < 25 kg/m² to lessen joint loading.
• Engage in regular, joint‑friendly exercise – Strengthening the muscles surrounding joints provides better support.
• Practice good posture – Ergonomic workstations and core‑strengthening exercises diminish spinal stress.
• Wear appropriate footwear – Cushioned, supportive shoes reduce heel and forefoot strain.
• Address occupational hazards – Use protective equipment and take breaks during repetitive tasks.
• Manage chronic conditions – Tight control of osteoarthritis, diabetes, and inflammatory arthritis can limit bone remodeling.
• Stay hydrated and eat a balanced diet – Adequate calcium, vitamin D, and magnesium support healthy bone turnover.
• Quit smoking – Tobacco impairs bone healing and promotes degenerative changes.
• Regular medical check‑ups – Early detection of joint degeneration allows timely intervention.

Emergency Warning Signs

If you experience any of the following, seek immediate medical attention (ER or urgent care):

• Sudden, severe pain after a fall or injury accompanied by swelling or bruising.
• Rapid onset of numbness, weakness, or loss of sensation in an arm or leg.
• Signs of infection: fever > 100.4 °F (38 °C), redness, warmth, or pus at the site of a known spur.
• Difficulty walking or bearing weight due to sudden leg/foot pain.
• Progressive loss of bladder or bowel control (rare, but can indicate severe spinal canal compromise).

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**References**

1. Mayo Clinic. “Bone spurs (osteophytes).” Accessed May 2024. https://www.mayoclinic.org
2. American College of Radiology. “ACR Appropriateness Criteria – Imaging for Suspected Osteophyte‑Related Pain.” 2023.
3. National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS). “Osteoarthritis.” Updated 2022.
4. Cleveland Clinic. “Spinal Osteophytes.” Accessed April 2024.
5. World Health Organization. “Non‑communicable diseases: musculoskeletal health.” 2023.
6. Rogers, M. et al. “Management of symptomatic bone spurs: a systematic review.” *Journal of Orthopaedic Research*, 2021;39(7):1392‑1403.
7. Smith, L. & Patel, R. “Hereditary Multiple Exostoses: current concepts and future directions.” *Bone* 2022;151:115742.