Bunion (Hallux Valgus)

Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management | References

Definition

A bunion, medically known as hallux valgus, is a bony deformity of the joint at the base of the big toe. It is characterised by lateral deviation of the big toe, which can cause the first metatarsal bone to protrude and lead to a painful bump on the side of the foot.

Aetiology

The development of bunions is multifactorial, involving:

• Genetic predisposition, where foot structure inherited from parents can contribute to bunion formation
• Wearing tight or ill-fitting shoes, particularly those with a narrow toe box or high heels
• Foot injuries or conditions such as arthritis that affect joint alignment
• Abnormal foot mechanics, such as overpronation or flat feet
• Chronic stress on the foot, particularly in individuals who stand for long periods

Pathophysiology

The pathophysiology of bunions involves:

• Gradual displacement of the big toe towards the second toe, leading to misalignment of the first metatarsophalangeal (MTP) joint
• Thickening of the tissues around the MTP joint, causing the characteristic bump on the side of the foot
• Inflammation and irritation of the bursa (fluid-filled sac) overlying the joint, leading to pain and swelling
• Progressive deformity of the foot, which can exacerbate symptoms and lead to further complications, such as hammertoes or metatarsalgia

Risk Factors

• Family history of bunions
• Wearing high-heeled or tight shoes
• Conditions such as rheumatoid arthritis or gout
• Flat feet or abnormal foot mechanics
• Occupations or activities that place prolonged stress on the feet
• Aging, as the risk of bunions increases with age

Signs and Symptoms

The signs and symptoms of bunions include:

• A visible bump on the side of the foot at the base of the big toe
• Pain and tenderness around the MTP joint, especially when wearing tight shoes
• Swelling and redness over the bunion
• Limited movement of the big toe
• Calluses or corns where the big toe overlaps the second toe
• In severe cases, development of secondary foot deformities, such as hammertoes

Investigations

Specific investigations to diagnose bunions include:

• Clinical examination: Physical assessment of the foot to identify the presence and severity of the bunion and associated deformities.
• Imaging studies:
  • X-rays: To assess the degree of misalignment of the MTP joint and any underlying bone deformities.
  • Ultrasound or MRI: Rarely used, but may be indicated to evaluate soft tissue involvement or in complex cases.

Management

Primary Care Management

• Footwear modification: Wearing shoes with a wide toe box, low heels, and adequate cushioning to reduce pressure on the bunion.
• Orthotic devices: Custom or over-the-counter orthotics to improve foot alignment and reduce stress on the MTP joint.
• Pain management: Analgesics such as paracetamol or NSAIDs to relieve pain and inflammation.
• Padding and taping: Using bunion pads to cushion the area and taping the foot to maintain proper alignment.
• Activity modification: Avoiding activities that exacerbate symptoms, such as prolonged standing or walking in tight shoes.

Specialist Management

• Physiotherapy: Referral to a physiotherapist for exercises to improve foot mechanics and strengthen supporting muscles.
• Corticosteroid injections: May be administered for severe inflammation and pain not responsive to conservative measures.
• Surgical intervention: Considered for persistent pain or severe deformity. Surgery may involve realigning the bones, removing the bunion, and correcting any associated deformities.
• Postoperative care: Includes physiotherapy and rehabilitation to restore function and prevent recurrence.

References

1. NHS (2024) Bunions. Available at: https://www.nhs.uk/conditions/bunions/ (Accessed: 24 June 2024).
2. National Institute for Health and Care Excellence (2024) Bunions (Hallux Valgus). Available at: https://cks.nice.org.uk/topics/bunions-hallux-valgus/ (Accessed: 24 June 2024).
3. British Medical Journal (2024) Bunions: Clinical Features, Diagnosis, and Management. Available at: https://www.bmj.com/content/350/bmj.h2910 (Accessed: 24 June 2024).
4. American Academy of Orthopaedic Surgeons (2024) Bunions (Hallux Valgus). Available at: https://orthoinfo.aaos.org/en/diseases--conditions/bunions-hallux-valgus/ (Accessed: 24 June 2024).

Back to Top