summary Hallux Valgus, commonly referred to as a bunion, is a complex valgus deformity of the first ray that can cause medial big toe pain and difficulty with shoe wear. Diagnosis is made clinically with presence of a hallux that rests in a valgus and pronated position. Radiographs of the foot are obtained to identify the severity of the disease and for surgical planning. Treatment can be nonoperative with shoe modifications for mild and minimally symptomatic cases. Surgical management is indicated for progressive deformity and difficulty with shoe wear. Epidemiology Demographics occurs in ~23% of patients 18 to 65 years old more common in women (up to 15:1) login to view 1 more bullet Risk factors intrinsic login to view 9 more bullets extrinsic login to view 1 more bullet Etiology Two forms exist adult hallux valgus adolescent & juvenile hallux valgus Pathoanatamy valgus deviation of phalanx promotes varus position of metatarsal the metatarsal head displaces medially, leaving the sesamoid complex laterally translated relative to the metatarsal head sesamoids remain within the respective head of the flexor hallucis brevis tendon and are attached to the base of the proximal phalanx via the sesamoid-phalangeal ligament this lateral displacement can lead to transfer metatarsalgia due to shift in weight-bearing medial MTP joint capsule becomes stretched and attenuated while the lateral capsule becomes contracted adductor tendon becomes deforming force login to view 1 more bullet lateral deviation of EHL further contributes to deformity plantar and lateral migration of the abductor hallucis causes muscle to plantar flex and pronate phalanx windlass mechanism becomes less effective login to view 1 more bullet Associated conditions hammer toe deformity callosities pes planus login to view 1 more bullet Marfan syndrome Ehlers-Danlos syndrome Juvenile and Adolescent Hallux valgus factors that differentiate juvenile/adolescent hallux valgus from adults login to view 5 more bullets complications login to view 3 more bullets Anatomy Pathoanatomy cascade Osteology valgus deviation of great toe and varus deviation of first metatarsal sesamoids displace lateral to metatarsal head loss of the windless mechanism results in transfer metatarsalgia Musculature muscles forming the plantar plate login to view 4 more bullets Presentation History slowly progressing deformity pain with ambulation Symptoms presents with difficulty with shoe wear due to medial eminence pain over prominence at MTP joint transfer metatarsalgia compression of digital nerve may cause symptoms Physical exam Hallux rests in valgus and pronated due to deforming forces illustrated above examine entire first ray for login to view 5 more bullets evaluate associated deformities login to view 3 more bullets Imaging Radiographs recommended views login to view 1 more bullet optional views login to view 1 more bullet findings login to view 3 more bullets Radiographic Measurements in Hallux Valgus Measurement Importance Normal Hallux valgus (HVA) Long axis of 1st MT and prox. phalanx Identifies MTP deformity < 15° Intermetatarsal angle (IMA) Between long axis of 1st and 2nd MT Identifies deformity of the metatarsal < 9 ° Distal metatarsal articular (DMAA) Between 1st MT axis and line through base of distal articular cap Identifies MTP joint incongruity < 15° Hallux valgus interphalangeus (HVI) Between long axis of distal phalanx and proximal phalanx Predisposing factor for hallux valgus < 10° Metatarsus adductus angle Angle between the second metatarsus and the longitudinal axis of the lesser tarsus (using the 4th or 5th metatarso-cuboid joint as a reference) Predisposing factor for hallux valgus < 10° Differential diagnosis Gout Hallux rigidus Rheumatoid arthritis Turf toe Hallux valgus interphalangeus Treatment - Adult Hallux Valgus Nonoperative shoe modification/ pads/spacers/orthoses login to view 3 more bullets Operative surgical correction login to view 52 more bullets Treatment - Juvenile and Adolescent Hallux valgus Nonoperative shoe modification login to view 2 more bullets Operative surgical correction login to view 9 more bullets Techniques Soft Tissue Procedures modified McBride login to view 12 more bullets Metatarsal Osteotomies distal metatarsal osteotomy login to view 13 more bullets proximal metatarsal osteotomy login to view 13 more bullets double (proximal and distal) osteotomy login to view 1 more bullet first cuneiform lateral opening osteotomy login to view 6 more bullets Proximal phalanx osteotomies Akin osteotomy login to view 4 more bullets Fusion procedures Lapidus procedure (1st metatarsocuneiform arthrodesis with modified McBride) login to view 6 more bullets MTP Arthrodesis login to view 9 more bullets Resection arthroplasty proximal phalanx (Keller) resection arthroplasty login to view 2 more bullets Surgical Indications for Specific Conditions Juvenile/Adolescent with open physis First cuneiform osteotomy Hypermobile 1st MT Lapidus procedure DJD MTP arthrodesis Skin breakdown Simple bunionectomy with medial eminence removal Gout MTP arthrodesis Recurrence with pain in 1st TMT joint Lapidus procedure Rheumatoid arthritis MTP arthrodesis Down's syndrome, CP, Ehlers-Danlos MTP arthrodesis Surgical Indications for Various Techniques to Treat Hallux Valgus HVA IMA Modifier Procedure Mild < 30° < 13° Distal MT osteotomy Chevron osteotomy Biplanar if DMAA > 10° with mod McBride Moderate 30-40° 13-20° Proximal MT +/- distal MT osteotomy Chevron/mod McBride + Akin Proximal MT osteotomy and mod McBride Severe > 40° > 20° Double osteotomy, DMAA > 15° Proximal MT osteotomy plus biplanar chevron, mod McBride Lapidus procedure plus Akin > 40° > 20° Elderly/very low demand patient Keller resection arthroplasty > 40° > 20° Juvenile/Adolescent with DMAA > 20 Double osteotomy of first ray Various Hallux valgus procedures Procedure Technique Indications Complications Modified McBride Includes release of adductor from lateral sesamoid/proximal phalanx, lateral capsulotomy, medial capsular imbrication HVA < 35° IMA < 11° HVI < 15° Recurrence Hallux varus Original McBride Includes lateral sesamoidectomy and has been abandoned Not indicated Hallux Varus Chevron Distal 1st MT osteotomy (intra-articular). Can perform in two planes (Biplanar distal Chevron) Reserved for mild to moderate deformities in adults and children Biplanar chevron--> corrects increased DMAA AVN of MT head Recurrence Dorsal malunion with transfer metatarsalgia Mitchell Distal 1st MT osteotomy (extra-articular). More proximal than Chevron Same as Chevron (rarely utilized) Recurrence Malunion Transfer metatarsalgia Akin Proximal phalanx medial closing wedge osteotomy Combined with Chevron in moderate to severe deformities Hallux valgus interphalangeus Scarf / Ludloff / Mau Metatarsal shaft osteotomies. HVA > 25°, IMA > 13° DMAA is normal or increased Dorsal malunion with transfer metatarsalgia Recurrence Proximal Crescentic or Broomstick Proximal metatarsal osteotomy plus modified McBride Severe deformity IMA > 13° HVA > 25° Hallux varus Dorsal malunion with transfer metatarsalgia Recurrence Keller resection arthroplasty Includes medial eminence removal and resection of base of proximal phalanx Largely abandoned due to complications Indicated only in older patients with reduced functional demands Cock-up toe deformity Poor potential for correction of deformity MTP arthrodesis HVA > 40 degrees, IMA > 20 degrees DJD of 1st MTP Neuromuscular conditions Painful callosities beneath lesser MT heads Lapidus procedure First TMT joint arthrodesis with distal soft tissue procedures (medial eminence removal, first web space release of AdH, lateral capsule release) Moderate or severe deformity Hypermobility of first ray Nonunion (may or may not be symptomatic) Dorsiflexion of the first metatarsal with transfer metatarsalgia First Cuneiform Osteotomy Opening wedge osteotomy (often requires autograft) Children with ligamentous laxity, flatfoot, and hypermobile first ray Adolescent with an open physis Nonunion (may or may not be symptomatic) Complications Recurrence incidence login to view 1 more bullet risk factors login to view 10 more bullets diagnosis login to view 1 more bullet treatment login to view 2 more bullets Avascular necrosis incidence login to view 1 more bullet risk factors login to view 2 more bullets diagnosis login to view 1 more bullet treatment login to view 1 more bullet Dorsal malunion with transfer metatarsalgia incidence login to view 1 more bullet risk factors login to view 4 more bullets diagnosis login to view 1 more bullet treatment login to view 2 more bullets Hallux Varus incidence login to view 1 more bullet risk factors login to view 4 more bullets diagnosis login to view 1 more bullet treatment login to view 3 more bullets Cock up toe deformity most severe complication with Keller resection incidence login to view 1 more bullet risk factors login to view 1 more bullet diagnosis login to view 1 more bullet treatment login to view 3 more bullets 2nd MT transfer metatarsalgia incidence login to view 1 more bullet risk factors login to view 2 more bullets diagnosis login to view 1 more bullet treatment login to view 1 more bullet Neuropraxia incidence login to view 1 more bullet risk factors login to view 2 more bullets diagnosis login to view 1 more bullet treatment login to view 1 more bullet Nonunion incidence login to view 2 more bullets risk factors login to view 1 more bullet diagnosis login to view 1 more bullet treatment login to view 1 more bullet Prognosis may take 6-12 weeks to return to work improvement may take 1year dissatisfaction 10-50% risk after surgical intervention login to view 2 more bullets