The etymology of bunion probably comes from the Old French word "bugne, "meaning "a swelling caused by a blow."
A bunion describes an inflamed advantageous bursa or fluid filled sac (like a balloon) which appears over the base of the big toe. The bursa may lie dormant or become inflamed (bursitis ) due to overlying shearing stress usually from shoes. Medial displacement of the first metatarsal head is a common symptom of triplane subluxation of the first metatarsal phalangeal joint commonly seen in hallux-abducto-dorsi-valgus (HADV). For convenience the term HADV is often shortened to Hallux Valgus (HV) or Hallux Abducto Valgus (HAV). This can and does lead to confusion. Bunions and HV often present clinically together but not all cases of HV will have a overlying bursitis.
A common error is to confuse bunions with the unsightly exostosis (bony bump) at the base of the great toe caused by joint misalignment at the first metatarsal phalangeal joint.
There are several reasons why Hallux-abducto-dorsi-valgus is caused but the consensus is instability at the rearfoot during late stance phase of gait causes hypermobility to move distally to the metatarso-phlangeal joints and causing them to subluxate. As a result the hallux (great toe) abducts (moves away from the midline of the body) on the transverse plane; everts (rotates along the long axis) on the frontal plane; and dorsiflexes on the sagital plane. The displaced hallux may overly (or underly) the second toe partially dislocating the digit, and causing a secondary hammer toe. This triplane deformity disarticulates the metartarsal phalangeal joint compromising its dual plane function, causing the metatarsal head to drift towards the mid line of the body. Osteoarthrosis (degenerative arthritis) may further compromise the interitiy of the joint and osteoarthrosis (degenerative arthritis) ensue. Prolonged external skin shearing over the bony prominence may excite a busitis. According a national survey by the American Academy of Orthopaedic Surgeons more than half of American women have measurable bunions (a lateral deviation of the hallux ≥ 20 degrees) but not are painful. They report nine out of 10 bunion cases affect women.
No one has ever been born with bunions or hallux-abductio-dorsi- valgus (HADV) but many people have a genetic pre-disposition . Bunions and HADV, affect women more than men and the former condition may be exacerbated by ill-fitting shoes, but this is rarely the primary cause. Discomfort from bunions include swollen, tender, big toe joints and joint pain, and stiffness. Lack of function may accompany HAV and can be alleviated by conservative means, such as stretching (traction), but conditions do apply. People living with developing bunions can also try a variety of conservative treatments, including wearing wider-toed shoes and foot orthoses to help restore proper balance in the foot. Should persistent pain continue then more drastic measures are required.
The surgical removal of a bursitis is a comparatively simple process with good outcome. A bunionectomy however, usually includes elective surgery for hallux-abducto-dorsi-valgus. There are many procedures and in the vast majority of cases (approx. 85%) very successful outcomes . However, as with all surgical procedures there is always a risk of complications including post operative infection, long healing times, delayed return to work as well as imperfect post-surgical results. These concerns should always be fully discussed with the surgeon before informed consent is give to proceed.
Depending on the type and severity, and the age and activity level of the person, there are several operating procedures including micro-surgery commonly carried out. By far the most preferred method involves reconstruction of the large bone (metatarsal) which supports the big toe. This has two main attractions; it keeps the metatarso-phalangeal joint intact as well as allowing the big toe joint to appear straight. Sometimes a wedge of bone may be removed or an area may be fused to keep it in position. Pins may be inserted and surrounding ligaments, tendons and nerves often must be realigned with the bones. In some cases, a walking cast may be required. Full recovery may take a year albeit this is the exception rather than the rule. Sadly, even with a perfect job, reoccurrence of the deviation of the toe does arise and although, for the majority, this does not involve irritating symptoms, surgery is not always a cure.
According to the Framingham Foot study into Hallux Abducto-Dosi- Valgus reseachers found genes more than shoes were likely to be the cause of the most common foot deformity. This is the first study to examine heretibility of foot disorders in white men and women of European descent, and 1,370 subjects were involved. Both men and women took part (mean age of 66 years and 57% were female) and the frequency of foot problems, including bunions as well as hammer and claw toes was recorded. Using estimated heritability software to perform genetic analyses of familial data (pedigree structures) they were able to estimate association. Hallux abducto-valgus and lesser toe deformity were found to be highly heritable depending on age and sex. The researchers suggested certain foot shapes, as determined by genetics, were predisposed to developing bunions. Previous studies have shown up to 60% of older adults have foot disorders which may limit mobility and reduce their quality of life. Despite its prevalence and sequestra there is little understanding of the genetics involved in the development of hallux abducto-valgus .The role of ill fitting footwear may exacerbate shear and friction across the skin surface and hence increase heat damaging the skin cell reproction resulting bursae formation and or callus and corns.
The American Academy of Orthopaedic Surgeons recommend people with prominent bumnions should wear good fitting shoes and avoid seems. Protective pads may also be used to help cushion the painful area. When persistent pain and difficulty walking follow it may be appropriate to undergo surgery. Bunion surgery realigns bone, ligaments, tendons, and nerves, bringing the big toe back to its normal position. Following bunion surgery, a long recovery is common and may include persistent swelling and stiffness.
The purspose of this post is for information only and not intended to be actual medical advice. In the event you are concerned with bunions and or hallux -abducto-valgus please consult your own foot physician or general practitoner for advice .
Hannan M. T. Hannan, Menz H B, Jordan J.M et al 2013 Hallux Valgus and Lesser Toe Deformities are Highly Heritable in Adult Men and Women: the Framingham Foot Study Arthritis Care Res (Hoboken). 65(9): 1515–1521.
DISEASES & CONDITIONS: What to do about bunions Harvard Health Publishing 2020.