> Table of Contents > Bunion (Hallux Valgus)
Bunion (Hallux Valgus)
Jennifer G. Chang, MD
image BASICS
DESCRIPTION
  • Lateral deviation of the great toe. Hallux valgus derives from the Latin for “big toe askew”; also commonly known as a bunion
  • Lateral deviation of the great toe with medial deviation of the 1st metatarsal leads to a medial prominence of the 1st metatarsophalangeal (MTP) joint and a potentially painful and/or debilitating deformity.
  • Progressive subluxation of the 1st MTP joint is common.
  • System(s) affected: musculoskeletal/skin
EPIDEMIOLOGY
  • Predominant age: more common in adults
    • Estimated 23% in adults aged 18 to 65 years
    • Estimated 35.7% in elderly >65 years
  • Predominant sex: female > male by ˜2:1
Prevalence
  • Prevalence increases with age particularly in females.
  • Juvenile hallux valgus
    • More common in girls (>80% of cases)
  • Commonly bilateral
  • Pain is not usually the presenting symptom.
ETIOLOGY AND PATHOPHYSIOLOGY
Multifactorial. Contributing factors include the following:
  • Valgus deviation of the hallux promotes varus position of the 1st metatarsal.
  • Medial MTP joint capsule stretches and attenuates while the lateral capsule contracts.
  • Metatarsal head moves medially, shifting the sesamoid bones to a more lateral position.
  • Extensor hallucis longus deviates laterally.
  • Lateral and plantar migration of abductor hallucis moves the great toe into plantar flexion and lateral pronation.
  • Medial collateral ligament stretches and eventually ruptures due to this deviation, decreasing stability and causing progressive subluxation of the 1st MTP joint.
RISK FACTORS
  • Familial predisposition
  • Abnormal biomechanics (i.e., flexible flat feet)
  • Joint laxity; pronation of hindfoot; Achilles tendon contracture; pes planus (fallen arches)
  • Metatarsus primus varus
  • Amputation of second toe
  • Inflammatory joint disease
  • Neuromuscular disorders
  • Improper footwear, narrow toe box
GENERAL PREVENTION
Proper footwear may decrease the progression of the disease.
COMMONLY ASSOCIATED CONDITIONS
  • Medial bursitis of the 1st MTP joint (most common)
  • Hammertoe deformity of the 2nd phalanx
  • Plantar callus
  • Metatarsalgia
  • Degeneration of 1st metatarsal head cartilage
  • Pronated feet; ankle equinus
  • Onychocryptosis (ingrown toenail)
  • Entrapment of the medial dorsal cutaneous nerve
  • Synovitis of the MTP joint
image DIAGNOSIS
  • Based on clinical exam
  • Radiographs are used for staging
PHYSICAL EXAM
  • Observe gait; may be antalgic due to pain
  • Increased distal metatarsal articular angle (DMAA)
  • Medial prominence at the MTP joint
  • Medial inflammation and ulceration at the MTP joint
  • Skin changes: inflammation, blistering, callus
  • Great toe over- or underriding the second toe
  • Examine the entire first ray for:
    • 1st MTP range of motion
    • 1st tarsometatarsal mobility
    • Neurovascular integrity
    • Degenerative osteoarthritis
DIFFERENTIAL DIAGNOSIS
  • Trauma
    • Turf toe; sesamoiditis; stress fracture
  • Infection
    • Osteomyelitis; septic arthritis
  • Joint disorder
    • Osteoarthritis; rheumatoid arthritis; pseudogout; gout
  • Tendon disorder
    • Tendinosis; tenosynovitis; tendon rupture
  • Other
    • Bursitis; ganglia; foreign body granuloma
DIAGNOSTIC TESTS & INTERPRETATION
  • Weight-bearing AP and lateral radiographs (sesamoid view optional) to assess:
    • Joint congruency and degenerative changes
    • Lateral sesamoid bone displacement (1)[A]
    • Rounded 1st MT head (1)[A]
    • Longer 1st metatarsal (1)[A]
  • Radiographic parameters:
    • Hallux valgus angle (HA): Long axis of the 1st MT and proximal phalanx is normally <15 degrees.
    • Intermetatarsal angle (IM): Between long axis of 1st and 2nd MT is normally <9 degrees.
    • DMAA: Between 1st MT long axis and line through base of distal articular cap is normally <15 degrees.
    • Hallux valgus interphalangeus: Between long axis of distal phalanx and proximal phalanx is normally <10 degrees.
image TREATMENT
  • Primary indication for treatment is pain.
  • There are conservative and surgical approaches.
  • Surgical treatment is generally more effective in improving pain but has attendant risks.
GENERAL MEASURES
Nonoperative treatment options may improve symptoms and delay the progression of hallux valgus deformity, although high-quality evidence is limited:
  • Proper fitting footwear: low-heeled, wide-toe shoes to decrease stress on MTP joint (i.e., wide toe box)
  • Orthoses to correct foot alignment (pes planus and overpronation). Improving gait may prevent bunion formation and reduce pressure on the MTP.
  • Night splinting: In theory, splinting stabilizes and balances soft tissue structures around the MTP. Limited evidence shows improvement in degree of angulation in mild hallux valgus.
  • Manual and manipulative therapy (MMT): stretches contracted soft tissue
  • Foot exercises and stretching to improve intrinsic foot muscle strength and increase range of motion
  • Pads/spacers: Pads decrease friction on the MTP joint. A toe spacer in the 1st interdigital space can straighten the hallux and may reduce pain (2)[C].
MEDICATION
  • Topical and PO medications (NSAIDs) can be used to relieve pain and swelling. Other topical options include capsaicin cream.
  • Corticosteroid injections improve pain.
ADDITIONAL THERAPIES
Custom orthoses are a safe intervention that may decrease pain at 6 and 12 months compared with no treatment; however, this improvement is less than that seen with surgical intervention (3)[B].
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SURGERY/OTHER PROCEDURES
  • Surgery is indicated if patient has severe pain, dysfunction, or persistent symptoms that do not abate with conservative therapy.
  • Surgery is beneficial for patients with severe symptoms (3)[B]:
    • >150 different surgical techniques to treat hallux valgus; none has been proven to be superior, and no universally accepted standard exists for selecting a particular procedure over another.
    • Choice of surgical technique depends on the severity of disease, the HA and IM angles, congruency and subluxation of the MTP joint, patient-specific factors, and the pathologic element the surgeon determines needs correcting. Examples include the following:
      • Arthrodesis: fusion of the 1st MTP joint; reserved for severe and/or recurrent hallux valgus
      • Arthroplasty: removing the joint or replacing it with a prosthesis
      • Exostectomy/bunionectomy: removing the medial bony prominence of the MTP joint
      • Soft tissue realignment: alters the function of surrounding ligaments and tendons; used for minor, flexible deformities
      • Osteotomy and realignment: can correct large deformities, but evidence of long-term outcome is lacking (4)[C]
      • Mini-tight rope procedure: use of a Fiberwire to correct the misalignment of the deformity; reportedly allows for faster recovery and earlier weight bearing (5)[C] but may have high complication and failure rates (6)[C]
  • Surgery can decrease pain and increase foot alignment. Some patients may have little to no improvement in symptoms despite interventions.
  • Establish realistic expectations prior to surgery (7)[C].
  • In pediatric patients, surgery should generally be delayed until skeletal maturity (8)[C].
COMPLEMENTARY & ALTERNATIVE MEDICINE
Marigold ointment may reduce pain and soft tissue swelling (9)[C].
image ONGOING CARE
FOLLOW-UP RECOMMENDATIONS
  • Postoperative treatment includes physical therapy, physiotherapy, supportive footwear, continuous passive motion, or manual manipulation.
  • Time until full weight bearing depends on the surgical procedure.
PROGNOSIS
Patient outcome varies depending on biomechanical factors, severity of the deformity, and treatment modality used. The radiologic HA angle predicts surgical outcomes. Patients with an HA angle <37 degrees have a higher chance of having the deformity successfully corrected with surgery compared with patients with an HA angle >37 degrees.
REFERENCES
1. Nix SE, Vicenzino BT, Collins NJ, et al. Characteristics of foot structure and footwear associated with hallux valgus: a systematic review. Osteoarthritis Cartilage. 2012;20(10):1059-1074.
2. Tehraninasr A, Saeedi H, Forogh B, et al. Effects of insole with toe-separator and night splint on patients with painful hallux valgus: a comparative study. Prosthet Orthot Int. 2008;32(1):78-83.
3. Torkki M, Malmivaara A, Seitsalo S, et al. Surgery vs orthosis vs watchful for hallux valgus: a randomized controlled trial. JAMA. 2001;285(19):2474-2480.
4. Choi JH, Zide JR, Coleman SC, et al. Prospective study of the treatment of adult primary hallux valgus with scarf osteotomy and soft tissue realignment. Foot Ankle Int. 2013;34(5):684-690.
5. Holmes GB Jr, Hsu AR. Correction of intermetatarsal angle in hallux valgus using small suture button device. Foot Ankle Int. 2013;34(4):543-549.
6. Dayton P, Sedberry S, Feilmeier M. Complications of metatarsal suture techniques for bunion correction: a systematic review of the literature. J Foot Ankle Surg. 2015;54(2):230-232.
7. Dux K, Smith N, Rottier FJ. Outcome after metatarsal osteotomy for hallux valgus: a study of postoperative foot function using revised foot function index short form. J Foot Ankle Surg. 2013;52(4):422-425.
8. Chell J, Dhar S. Pediatric hallux valgus. Foot Ankle Clin. 2014;19(2):235-243.
9. Deenik AR, de Visser E, Louwerens JW, et al. Hallux valgus angle as main predictor for correction of hallux valgus. BMC Musculoskelet Disord. 2008;9:70.
Additional Reading
  • Maffulli N, Longo UG, Marinozzi A, et al. Hallux valgus: effectiveness and safety of minimally invasive surgery. A systematic review. Br Med Bull. 2011;97:149-167.
  • Nix S, Smith M, Vicenzino B. Prevalence of hallux valgus in the general population: a systemic review and meta-analysis. J Foot Ankle Res. 2010;3:21.
  • Perera AM, Mason L, Stephens MM. The pathogenesis of hallux valgus. J Bone Joint Surg Am. 2011;93(17):1650-1661.
  • Smith SE, Landorf KB, Butterworth PA, et al. Scarf versus chevron osteotomy for the correction of 1-2 intermetatarsal angle in hallux valgus: a systematic review and meta-analysis. J Foot Ankle Surg. 2012;51(4):437-444.
  • Trnka HJ, Krenn S, Schuh R. Minimally invasive hallux valgus surgery: a critical review of the evidence. Int Orthop. 2013;37(9):1731-1735.
Codes
ICD10
  • M20.10 Hallux valgus (acquired), unspecified foot
  • M20.11 Hallux valgus (acquired), right foot
  • M20.12 Hallux valgus (acquired), left foot
Clinical Pearls
  • Avoid footwear with high heels, pointed toe boxes, or inadequate toe space to reduce development or progression of bunions.
  • Surgery generally results in superior outcomes for pain relief in appropriately selected patients.
  • No single surgical method has shown to be superior for long-term pain relief.
  • Establish realistic expectations prior to surgery to improve patient satisfaction with surgical outcomes.