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Bunion (Hallux Valgus)

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Bunion (Hallux Valgus)

BASICS

DESCRIPTION

Multifactorial. Contributing factors include the following:

Nonoperative treatment options may improve symptoms and delay the progression of hallux valgus deformity, although high-quality evidence is limited:

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].

Marigold ointment may reduce pain and soft tissue swelling (9)[C].

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.

11 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):1059-1074.22 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 Ortho Int. 2008;32(1):78-83.33 Torkki M, Malmivaara A, Seitsalo S, et al. Surgery vs orthosis vs watchful for hallux valgus: a randomized controlled trial. JAMA. 2001;285(19):2474-2480.44 Choi JH, Zide JR, Coleman SC, et al. Prospective study of treatment of adult primary hallux valgus with scarf osteotomy and soft tissue realignment. Foot Ankle Int. 2013;34(5):684-690.55 Holmes GB, Hsu AR. Correction of intermetatarsal angle in hallux valgus using small suture button device. Foot Ankle Int. 2013;34(4):543-549.66 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):230-232.77 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):422-425.88 Chell J, Dhar S. Pediatric hallux valgus. Foot Ankle Clin. 2014;19(2):235-243.99 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.

  • 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 adultsEstimated 23% in adults aged 18 to 65 yearsEstimated 35.7% in elderly >65 years
  • Predominant sex: female > male by ~2:1
  • Estimated 23% in adults aged 18 to 65 years
  • Estimated 35.7% in elderly >65 years
  • Prevalence increases with age particularly in females.
  • Juvenile hallux valgusMore common in girls (>80% of cases)
  • Commonly bilateral
  • Pain is not usually the presenting symptom.
  • More common in girls (>80% of cases)

ETIOLOGY AND PATHOPHYSIOLOGY

  • 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

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

DIAGNOSIS

  • Based on clinical exam
  • Radiographs are used for staging

HISTORY

  • Painful MTP joint (most common symptom in adults)
  • Abnormal position of great toe
  • Enlargement of the MTP joint medially (patients complain of a "bump")
  • Shoes don't fit properly
  • Pain on ambulation
  • Skin irritation, blistering, callus formation at 1st MTP

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 motion1st tarsometatarsal mobilityNeurovascular integrityDegenerative osteoarthritis
  • 1st MTP range of motion
  • 1st tarsometatarsal mobility
  • Neurovascular integrity
  • Degenerative osteoarthritis

DIFFERENTIAL DIAGNOSIS

  • TraumaTurf toe; sesamoiditis; stress fracture
  • InfectionOsteomyelitis; septic arthritis
  • Joint disorderOsteoarthritis; rheumatoid arthritis; pseudogout; gout
  • Tendon disorderTendinosis; tenosynovitis; tendon rupture
  • OtherBursitis; ganglia; foreign body granuloma
  • Turf toe; sesamoiditis; stress fracture
  • Osteomyelitis; septic arthritis
  • Osteoarthritis; rheumatoid arthritis; pseudogout; gout
  • Tendinosis; tenosynovitis; tendon rupture
  • Bursitis; ganglia; foreign body granuloma

DIAGNOSTIC TESTS & INTERPRETATION

  • Weight-bearing AP and lateral radiographs (sesamoid view optional) to assess:Joint congruency and degenerative changesLateral 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.
  • Joint congruency and degenerative changes
  • Lateral sesamoid bone displacement (1)[A]
  • Rounded 1st MT head (1)[A]
  • Longer 1st metatarsal (1)[A]
  • 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.

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

  • 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

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 valgusArthroplasty: removing the joint or replacing it with a prosthesisExostectomy/bunionectomy: removing the medial bony prominence of the MTP jointSoft tissue realignment: alters the function of surrounding ligaments and tendons; used for minor, flexible deformitiesOsteotomy 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].
  • >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 valgusArthroplasty: removing the joint or replacing it with a prosthesisExostectomy/bunionectomy: removing the medial bony prominence of the MTP jointSoft tissue realignment: alters the function of surrounding ligaments and tendons; used for minor, flexible deformitiesOsteotomy 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]
  • 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]

COMPLEMENTARY & ALTERNATIVE MEDICINE

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

COMPLICATIONS

  • Risks associated with surgery include infection, persistent pain, and poor cosmetic result.
  • Additional risks vary with the surgical procedure.
  • Other complications may include:Early swellingHallux varusRecurrence of bunionMetatarsal fractureDecreased sensation over the 1st metatarsal or phalanx
  • Early swelling
  • Hallux varus
  • Recurrence of bunion
  • Metatarsal fracture
  • Decreased sensation over the 1st metatarsal or phalanx

REFERENCES

ADDITIONAL READING

  • Mafulli NI, Longo UG, Marinozzi AN, et al. Hallux valgus: effectiveness and safety of minimally invasive surgery. A systematic review. Br Med Bull. 2010;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

ICD9

  • 727.1 Bunion
  • 735.0 Hallux valgus (acquired)

SNOMED

  • 415692008 swelling of first metatarsophalangeal joint of hallux (disorder)
  • 118623005 hallux valgus AND bunion (disorder)
  • 1075071000119103 Swelling of first metatarsal joint of hallux of left foot (disorder)
  • 1075051000119107 Swelling of first metatarsal joint of hallux of right foot (disorder)

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.