Dr. Kevin Yip

Dr Kevin Yip
Orthopaedic Surgeon
MBBS(UK), FRCS(EDIN), FAM(SING), FHKCOS(ORTHO)

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Bunion/Hallux Valgus

Basics
Description
  • A bunion is an enlargement of the medial eminence of the 1st metatarsal with soft tissue and bursal swelling.
  • Hallux valgus occurs primarily at the MTP joint and consists of lateral deviation of the great toe with medial deviation of the 1st metatarsal.
  • Subluxation of the MTP joint often occurs.
General Prevention
Avoidance of narrow footwear
 
Epidemiology
  • Occurs predominantly in middle-aged to elderly women, but can be seen in adolescents and young adults
  • Females are affected more than males.
  • Occurs almost exclusively in shoe-wearing societies
Prevalence
Reported to occur in up to 33% of individuals
 
Risk Factors
  • Heredity
  • Shoe wear
Genetics
  • May be an unidentified genetic component
  • Positive family history in 2/3 of patients
  • Hallux valgus also is seen commonly as a component of a hyperlaxity syndrome that is thought to have a genetic component.
Etiology
  • Shoes with narrow toe boxes and high heels are believed to be related to the development of hallux valgus.
    • Higher incidence in shod versus unshod societies and increasing incidence in populations that adopt more Westernized shoe styles.
  • Pes planus also may be a causative factor: Part of a laxity syndrome and associated with mechanically abnormal pressure on the 1st MTP joint secondary to a pronated gait.
  • Metatarsus primus varus is associated; a strong relationship exists between an increase in the angle between the 1st and 2nd metatarsal joints and the development of hallux valgus.
  • Acquired joint laxity (e.g., from rheumatoid arthritis, gout, or trauma) can contribute to the development.
  • Other miscellaneous conditions (e.g., amputation of another toe, severe hammering of the toes, Achilles tendon contracture) also may be associated.
Diagnosis
Signs and Symptoms
  • The primary symptom is pain over the medial eminence, often caused by shoe wear pressure.
  • The patient has lateral deviation of the great toe and prominence of the medial eminence.
  • The deformity may be accentuated with weightbearing.
  • When the condition is advanced, impingement by the great toe on the 2nd toe can lead to 2nd-toe pain and deformity.
  • Can be associated with pain under the 2nd metatarsal head (transfer metatarsalgia), 1st metatarsal joint pain, and arthritis.
  • Patients’ complaints often are cosmetically based and concern difficulty with shoe wear.
Physical Exam
  • Examine the sitting and standing patient.
  • Assess for Achilles tendon and gastrocnemius contracture with the knee flexed and extended (indicated by limited ankle dorsiflexion).
  • Check motion at the ankle, subtalar, midfoot, and metatarsal joints.
  • Manually assess for increased laxity or instability of the 1st metatarsocuneiform joint with vertical shear or stress.
  • Assess the flexibility or rigidity of the hallux valgus deformity by manually reducing the alignment of the toe.
  • Pay attention to foot morphology and arch status.
  • Perform a complete neurovascular and musculoskeletal examination of the entire lower extremity.
Tests
Imaging
  • Obtain standing AP, oblique, lateral, and axial (sesamoid) foot radiographs.
    • Assess for the intermetatarsal angle, hallux valgus angle, hallux IP angle, distal metatarsal articular angle, and the sesamoid incongruence.
    • Evaluate for joint incongruence and arthrosis, which greatly influences the treatment plan.
    • Evaluate lesser toe alignment.
Pathological Findings
  • 2 broad categories of hallux valgus occur, each with different entities and different pathoanatomic features: A noncongruent joint and a congruent joint.
  • Incongruent joint:
    • Multiple static and dynamic anatomic components
    • The 1st metatarsal head drifts medially (varus), thus increasing the angle between the 1st and 2nd metatarsals.
    • The sesamoid complex is held in place by the transverse metatarsal ligament and thus becomes relatively laterally positioned as the metatarsal head displaces medially.
    • With progressive deformity, the axis of pull for the adductor hallucis, the flexor hallucis brevis, extensor hallucis longus, and the abductor hallucis become lateralized, which dynamically contributes to the lateral displacement of the great toe.
    • The medial joint capsule and ligaments become attenuated, whereas the lateral joint capsule and ligaments become contracted.
  • Congruent joint:
    • A laterally sloped articular surface is present, with no pathologic articulation, so progression of deformity is less likely.
Differential Diagnosis
Gout
 
Treatment
General Measures
  • Hallux valgus should be treated initially with nonoperative measures.
  • Appropriate shoe wear is essential.
    • Pointed shoes and high heels must be avoided.
    • Lace-up styles have wider forefeet.
    • Soft leather shoes can be stretched to accommodate the bunion.
    • No stitching should be present over the medial eminence.
  • Numerous off-the-shelf cushions, pads, or splinting devices may alleviate pressure over the medial bunion.
  • Heel cord stretching and custom orthotic arch support may have a role for patients with associated Achilles contracture and pes planus.
  • Prescription shoes, wide with increased depth, can be ordered if needed.
Special Therapy
Physical Therapy
Not usually helpful for symptom relief
  
Medication (Drugs)
Analgesic medications may be necessary for symptomatic control.
 
Surgery
  • Goals of surgery: Pain relief, correction of the deformity, restoration of normal biomechanics, and maintenance of adequate joint motion
  • Indications for surgery:
    • Failed nonsurgical treatments
    • Worsening pain and deformity
    • Decreased function and inability to tolerate shoe wear
  • Contraindications for surgery:
    • Cosmetic complaints alone without symptoms
    • Vascular insufficiency
  • Options:
    • Multiple surgical procedures exist.
    • A decision tree for appropriate care is based on multiple factors.
      • Age
      • The angle between the 1st and 2nd metatarsal joint (normal, 9°)
      • The MTP angle (normal, 15°)
      • Congruity or incongruity of the joint
      • In the presence of degenerative joint disease, the options are to fuse or to place a prosthesis; currently, prosthesis technology is associated with high complication and failure rates and is not recommended for active individuals.
      • The presence of a rigid joint
  • Overview of surgical procedures:
    • Silver procedure:
      • Resection of the medial eminence should be used only for elderly patients.
      • Low complication rate, high recurrence rate
    • Modified McBride procedure:
      • Soft-tissue repair with resection of the medial eminence; release of the contracted lateral joint capsule, adductor hallucis tendon, and transverse metatarsal ligament; and imbrication of the medial capsule
      • Corrects hallux valgus angle
      • Can be used for mild deformities
      • More effective when performed with a proximal metatarsal osteotomy
      • Complications include hallux varus (overcorrection) and stiffness.
    • Distal metatarsal chevron osteotomy combined with a medial eminence resection and medial capsule plication:
      • The metatarsal head fragment is translated laterally, correcting intermetatarsal angle.
      • Appropriate for mild to moderate deformity (cannot adequately correct more severe deformities)
      • Can be complicated by malunion, osteonecrosis, or hallux varus
    • Metatarsocuneiform arthrodesis and distal soft-tissue correction (Lapidus procedure):
      • For hallux valgus deformities with hypermobility or instability of 1st metatarsocuneiform joint
      • Corrects increased intermetatarsal angle
      • Combined with modified McBride correction at the MTP joint
    • Proximal metatarsal osteotomy and distal soft-tissue correction:
      • For more severe hallux valgus deformities
      • Corrects increased intermetatarsal angle
      • Numerous configurations of proximal osteotomies have been described, including crescentic, oblique, opening wedge, and proximal chevron osteotomies.
      • Combined with modified McBride correction at the MTP joint.
    • MTP arthrodesis:
      • For severe deformities in elderly individuals; hallux valgus with degenerative or inflammatory arthritis, underlying spasticity, or connective tissue disorders, and as salvage for failed surgery
      • Fusion has dependable rates of pain relief and satisfaction but does result in hallux stiffness.
    • Resection arthroplasty (Keller) bunionectomy:
      • Involves removal of the medial eminence and base of the proximal phalanx
      • Appropriate only for older, sedentary patients
      • Can be associated with multiple complications, including recurrent valgus, transfer metatarsalgia, and cock-up 1st toe.
    • Akin phalangeal osteotomy procedure:
      • A medial closing wedge osteotomy of the proximal phalanx
      • For isolated hallux valgus interphalangeus or in combination with more proximal metatarsal osteotomy or fusion
Follow-up
Prognosis
  • Mild deformities and congruent deformities have lower rates of progression with nonoperative management than do severe or incongruent deformities.
  • Surgical treatment with appropriate indications and decision-making typically results in pain relief and deformity correction in most patients.
Complications
Surgical complications include wound breakdown and infection, recurrence of the deformity, overcorrection leading to hallux varus, malunion or nonunion of osteotomy or fusion procedures, joint stiffness, neuroma, and transfer metatarsalgia.
 
Miscellaneous
Codes
ICD9-CM
  • 727.1 Bunion
  • 735.0 Hallux valgus
  • 754.52 Metatarsus primus varus
Patient Teaching
Activity
Once the patient is no longer in the perioperative period, few limitations are placed on activity.
Prevention
The most important factor in prevention is the use of proper shoe wear and the avoidance of high-heeled shoes with narrow toe boxes.
 
FAQ
Q: When is bunion surgery indicated?
A: Bunion surgery is indicated for painful lesions that have not responded to nonoperative therapy, including trials of wide toe-box shoe wear.
 
Q: What can be done to prevent recurrence?
A: Avoidance of high-heeled, narrow toe-box shoe wear is critical to preventing recurrence.

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