Bunion

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Bunion
Other namesHallux abducto valgus, hallux valgus [1]
Hallux Valgus-Aspect pre op decharge.JPG
Specialty Orthopedics, podiatry
Symptoms Prominent, red, and painful joint at the base of the big toe [2]
Complications Bursitis, arthritis [2]
Usual onsetGradual [2]
Causes Unclear [1]
Risk factors Wearing overly tight shoes, high-heeled shoes, family history, rheumatoid arthritis [2] [3]
Diagnostic method Based on symptoms, X-rays [2]
Differential diagnosis Osteoarthritis, Freiberg's disease, hallux rigidus, Morton's neuroma [4]
TreatmentProper shoes, orthotics, NSAIDs, surgery [2]
Frequency~23% of adults [1]

A bunion, also known as hallux valgus, is an outward deformity of the foot's metatarsophalangeal (MTP) joint which connects the big toe to the foot. [2] The rear tarsametatarsal joint that holds the metatarsal bone in a straight-ahead position weakens, the metatarsal moves outward plus rotates 90 degrees bringing the sesamoids up against the adjacent toe. This results in the head of the metatarsal bulging outward, and the big toe then bends inward toward the other toes. The joint often becomes red and painful due to rubbing in a cramped shoe. [2] The onset of bunions is typically gradual. [2] Joint complications may include bursitis or arthritis. [2] A similar condition of the little toe is referred to as a bunionette. [2]

Contents

X-rays showing effect of bunion splints on angle of Hallux valgus in patients.jpg

Treatment may include proper shoes, orthotics, or NSAIDs. [2] If this is not effective for improving symptoms, surgery may be performed. [2] It affects about 23% of adults. [1] Females are affected more often than males. [2] Usual age of onset is between 20 and 50 years old. [1] The condition also becomes more common with age. [1] It was first clearly described in 1870. [1] Archaeologists have identified a high incidence of bunions in skeletons from 14th- and 15th-century England, coinciding with a fashion for pointy shoes. [5] [6]

Signs and symptoms

Drawing of a bunion Bunion (cropped).png
Drawing of a bunion

Symptoms may include irritation of the skin around the bunion, and blisters may form more easily at the site. Pain may be worse when walking.

Bunions can lead to difficulties finding properly fitting footwear and may force a person to buy a larger size shoe to accommodate the width of the bunion. If the bunion deformity becomes severe enough, the foot can hurt in different places even without the constriction of shoes. It is then considered as being a mechanical function problem of the forefoot.

Cause

High heels are associated with developing bunions. VerbildeteFusseNormaleFusse.gif
High heels are associated with developing bunions.

The exact cause is unclear. [1] It can be due to a combination of internal and external causes. [7] Proposed factors include wearing overly tight shoes, high-heeled shoes, family history, and rheumatoid arthritis. [2] [3] The American College of Foot and Ankle Surgeons states that footwear only worsens a problem caused by genetics. [8] Diagnosis is based upon simple viewing of the foot, symptoms of pain, and by X-rays. [2] Excessive low arch to a flat foot inward anke pronation of the foot also can cause increased pressure on the inside of the big toe that can result in a deformation of the medial capsular structures of the joint subsequently increasing the risk of developing a bunion. [7] [9]

Pathophysiology

The bump itself is due to the head of the metatarsal partly due to the swollen bursal sac or an osseous (bony) anomaly on the metatarsophalangeal joint. The larger part of the bump is a normal part of the head of the first metatarsal bone that has tilted sideways to stick out at its distal (far) end (metatarsus primus varus).

Bunions are commonly associated with a deviated position of the big toe toward the second toe, and the deviation in the angle between the first and second metatarsal bones of the foot. The small sesamoid bones found beneath the first metatarsal (which help the flexor tendon bend the big toe downwards) may also become deviated over time as the first metatarsal bone drifts away from its normal position. Osteoarthritis of the first metatarsophalangeal joint, diminished or altered range of motion, and discomfort with pressure applied to the bump or with motion of the joint, may all accompany bunion development. Atop of the first metatarsal head either medially or dorso-medially, there can also arise a bursa that when inflamed (bursitis), can be the most painful aspect of the process.

Diagnosis

X-ray showing measurements of HV and IM angles of hallux valgus. HV and IM angles of hallux valgus.jpg
X-ray showing measurements of HV and IM angles of hallux valgus.

Bunions can be diagnosed and analyzed with a simple x-ray, which should be taken with the weight on the foot. [10] The hallux valgus angle (HVA) is the angle between the long axes of the proximal phalanx and the first metatarsal bone of the big toe. It is considered abnormal if greater than 15–18°. [11] The following HV angles can also be used to grade the severity of hallux valgus: [12] [ unreliable medical source? ]

The intermetatarsal angle (IMA) is the angle between the longitudinal axes of the first and second metatarsal bones, and is normally less than 9°. [11] The IM angle can also grade the severity of hallux valgus as: [12]

Treatment

Conservative treatment for bunions include changes in footwear, the use of orthotics (accommodative padding and shielding), rest, ice, and pain medications such as acetaminophen or nonsteroidal anti-inflammatory drugs. These treatments address symptoms but do not correct the actual deformity. [13] If the discomfort persists and is severe or when aesthetic correction of the deformity is desired, surgical correction by an orthopedic surgeon or a podiatric surgeon may be necessary.

Orthotics

Gel toe spacers come in a variety of sizes and shapes. Pointe shoe toe spacers.jpg
Gel toe spacers come in a variety of sizes and shapes.

Orthotics are splints or regulators while conservative measures include various footwear like toe spacers, valgus splints, and bunion shields. Toe spacers seem to be effective in reducing pain, but there is no evidence that any of these techniques reduces the physical deformity. There are a variety of available orthotics including off-the-shelf commercial products and custom-molded orthotics, which may be prescribed medical devices. [14]

Surgery

Procedures are designed and chosen to correct a variety of pathologies that may be associated with the bunion. For instance, procedures may address some combination of:

Before and after effects of bunionplasty Bunionplasty Plastic Closure.jpg
Before and after effects of bunionplasty

At present there are many different bunion surgeries for different effects. The age, health, lifestyle and activity level of the patient may also play a role in the choice of procedure.

Traditional bunion surgery can be performed under local, spinal or general anesthetic. A person who has undergone bunion surgery can expect a 6- to 8-week recovery period during which crutches are usually required to aid mobility. An orthopedic cast is much less common today as newer, more stable procedures and better forms of fixation (stabilizing the bone with screws and other hardware) are used. Hardware may even include absorbable pins that perform their function and are then broken down by the body over the course of months. After recovery long term stiffness or limited range of motion may occur in some patients. Visible or limited scarring may also occur for patients.

Bunionectomy Bunionectomy.png
Bunionectomy

References

  1. 1 2 3 4 5 6 7 8 Dayton, Paul D. (2017). Evidence-Based Bunion Surgery: A Critical Examination of Current and Emerging Concepts and Techniques. Springer. pp. 1–2. ISBN   9783319603155.
  2. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 "Bunions". OrthoInfo - AAOS. February 2016. Retrieved 8 November 2017.
  3. 1 2 3 Barnish, MS; Barnish, J (13 January 2016). "High-heeled shoes and musculoskeletal injuries: a narrative systematic review". BMJ Open. 6 (1): e010053. doi:10.1136/bmjopen-2015-010053. PMC   4735171 . PMID   26769789.
  4. Ferri, Fred F. (2010). Ferri's Differential Diagnosis E-Book: A Practical Guide to the Differential Diagnosis of Symptoms, Signs, and Clinical Disorders. Elsevier Health Sciences. p. 323. ISBN   978-0323081634.
  5. Dittmar, Jenna; Mitchell, Piers (11 June 2021). "Fashion for pointy shoes unleashed a wave of bunions in medieval England". The Conversation. Retrieved 2021-06-28.
  6. Dittmar, Jenna M.; Mitchell, Piers D.; Cessford, Craig; Inskip, Sarah A.; Robb, John E. (2021-06-11). "Fancy shoes and painful feet: Hallux valgus and fracture risk in medieval Cambridge, England". International Journal of Paleopathology. 35: 90–100. doi: 10.1016/j.ijpp.2021.04.012 . ISSN   1879-9817. PMC   8631459 . PMID   34120868.
  7. 1 2 Brukner, Peter (2010). Clinical sports medicine (3 ed.). McGraw-Hill. p. 667. ISBN   9780070278998.
  8. "Bunions (Hallux Abducto Valgus)". Footphysicians.com. 2009-12-18. Archived from the original on 2011-12-08. Retrieved 2011-03-20.
  9. Chou, Loretta B. (19 June 2015). "Disorders of the First Metatarsophalangeal Joint". The Physician and Sportsmedicine. 28 (7): 32–45. doi:10.3810/psm.2000.07.1075. PMID   20086649. S2CID   21529142.
  10. Page 533 in: Sam W. Wiesel, John N. Delahay (2007). Essentials of Orthopedic Surgery (3 ed.). Springer Science & Business Media. ISBN   9780387383286.
  11. 1 2 Rebecca Cerrato, Nicholas Cheney. "Hallux Valgus". American Orthopaedic Foot & Ankle Society. Archived from the original on 2016-12-30. Retrieved 2016-12-30. Last reviewed June 2015
  12. 1 2 Piqué-Vidal, Carlos; Vila, Joan (2009). "A geometric analysis of hallux valgus: correlation with clinical assessment of severity". Journal of Foot and Ankle Research. 2 (1): 15. doi: 10.1186/1757-1146-2-15 . ISSN   1757-1146. PMC   2694774 . PMID   19442286.
  13. Hecht, PJ; Lin, TJ (March 2014). "Hallux valgus". Medical Clinics of North America (Review). 98 (2): 227–32. doi:10.1016/j.mcna.2013.10.007. PMID   24559871.
  14. Park, CH; Chang, MC (May 2019). "Forefoot disorders and conservative treatment". Yeungnam University Journal of Medicine. 36 (2): 92–98. doi:10.12701/yujm.2019.00185. PMC   6784640 . PMID   31620619. (see Figure Two for images of orthotics)