HAV Flashcards
What is HAV/what does it involve?
HAV is a progressive forefoot deformity, involving lateral deviation and valgus rotation of the first toe
What are risk factors of HAV?
Structural/biomechanical, arthritis, neuromuscular, trauma, other (age, gender, hereditary, congential)
What are structural considerations of HAV?
Pes planus/pes planovalgus Increased 1st intermetatarsal angle Long first metatarsal Round first metatarsal head Increased lateral tilt of 1st metatarsal articular surface Increased mobility at the 1st metatarso-cuneiform jiont Generalised joint hypermobility Comp FFVl Excessive rearfoot pronation
What are types of arthritis that can cause HAV?
Rheumatoid arthritis
Osteoarthritis
Psoriatic arthritis
What are neuromuscular issues that can cause HAV?
Muscle imbalance:
- intrinsic weakness
- imbalance between abductor hallucis
- reduced hallux plantarflexion strength
Neuromuscular disorders (often associated with ligamentous laxity): down syndrome, marfan syndrome, LMN, poliomyelitis, CP
What type of trauma can cause HAV?
Footwear - repetitive microtrauma from shoes with narrow/pointed toe box OR frequency wearing high heels
Acquired secondary to surgery
Direct injury to joint
What are the grades of HAV?
Grade 1-4 1 - no deformity 2 - mild HAV 3 - moderate HAV 4 - severe HAV
What happens to the following in HAV:
- 1stMTPJ, sesamoids, ligaments, 1st ray, intrinsic & extrinsic muscles
1st MTPJ: lateral deviation of hallux, progressive joint subluxation, development of OA
Sesamoids: bone laterally displaced, damage and erode crista, medial sesamoid then occupies lateral sesamoid groove, lateral sesamoid drifts into first IM space
Ligaments: medial capsule stretches & lateral capsule tightens
Medial bony eminence often develops
1st Ray: hypermobile and unstable during propulsive phase of gait
Intrinsic muscle: transverse head of adductor hallucis pulls the toe further into a lateral position as it has an advantage over abductor hallucis
Extrinsic muscles: EHL and FHL cause bow string to further abduct the hallux
What are angles to look at on radiology?
HV angle (normal = 15) IM angle (<9) Prox articular set angle (0-8) Distal articular set angle (0-6) Degree of sesamoid displacement
What are gait contributing factors of HAV?
Considerations:
- is excessive rearfoot pronation a factor
- sagittal plane collapse due to hypermobility to the 1st metatarsal-cuneiform joint
What are footwear contributing factors of HAV?
Difficulty finding footwear - width
History wearing high heels
What are treatment options for HAV?
Wider, lower heeled shoes Bunion pads IC OTC NSAIDS Orthoses Shoe mods Strengthening exercises Toe separators
What are types of surgeries for HAV?
Bunionectomy: removal of medial eminence
Osteotomy: realigns 1st met shaft
Arthoplasty: in severe cases, removal of base of phalanx
Arthodesis: joint fusion
what is footwear advice for HAV?
Wide toe box
Flat sole
Avoid straps/stitching irritation on med eminence
