61/62/63: HAV Surgery - Feilmeier Flashcards
hallux abductus valgus means …
- The great toe (hallux) is deviated away from the midline of the body in the transverse plane (abducto) and rotated away from the midline of the body in the frontal plane (valgus)
- *Tri plane description using frontal plane definition of valgus
why would you call a bunion metatarsus primus varus?
- The distal portion of the first metatarsal (metatarsus primus) is deviated toward the midline of the body (varus)
- This descriptor refers to the transverse plane in the foot
review of actions in planes
hick’s ROM first met
adduction, dorsiflexion, inversion/varus
BUT current research suggests it may actually be adduction, dorsiflexion, eversion/valgus
seasamoids pointing toward second met
valgus
sesamoids more toward midline = varus
describe what a bunion really is
hallux = hallux abducto valgus
metatarsal = metatarsus primus adducto valgus
- use tri-axial orthogonal coordinate system
- describes multi-planar position
what is happening in coronal plane in HAV?
- valgus metatarsal rotation (pronation)
- pronation of the first met is third plane of deformity
larger the bunion (greater IM angle) …
more frontal plane rotation (generally)
true or false: the first met is supinated/varus in a bunion deformity
false
this goes against Hick’s definition
what might you find on AP studies of a foot with bunion?
***
- lateral rounding of met head
- lateral displacement of sesamoids
- lateral roudning of met shaft
- lateral shift of plantar tuberosity
capsulorrhapphy
medially tightening the capsule to brings sesamoids more medial and in-line with the met
deformity correction goal: line up anatomic and mechanical axis
define mechanical and anatomic axis
define CORA
- CORA = center of rotation angulation
- Intersection of the Proximal Anatomic Axis (PAA) and Distal Anatomic Axis (DAA) of the two segments being corrected
- Bunion CORA = at the metatarsal cuneiform jt
- axis of correction of angulation ACA in met will produce a new deformity
define PASA
- change in where the cartilage of 1st met head is located realtive to met itself
- measured by putting transverse line through cartilage, anatomic axis, line perpindicular to anatomic axis. Normal 0-8
- some consider PASA to be radiographic artifact, least reliable measurement
- IF PASA is intirinsic to bone, should not change follwoing proximal correction procedures (reverden procedure at head should be only way to fix, distal procedure options should not work- they do)
Concepts to consider as causes for
less than optimum outcomes
- Disregard for the level of deformity
- Not fixing the original deformity at the CORA
- Failing to restore the anatomy in all three planes
- Focusing solely on the transverse plane of the deformity
- Inaccurate representation of PASA
- This transverse plane measurement may be just an artifact
- Unpredictability of soft tissue balancing as a component of the corrective procedure
- MTPJ capsular balancing for correction of sesamoid and hallux alignment does not offset the lack of alignment produced by the osteotomy and deteriorates in time
- What plane does the hallux primarily move in in a “normal foot”?
- What anatomic structures are a part of this?
- What happens if the hallux rotates into a vaglus position in the frontal plane?
- What movement occurs now to the hallux now?
- What impact might this have on the first metatarsal?
- What plane does the hallux primarily move in in a “normal foot”? sagittal
- What anatomic structures are a part of this? extensor and flexors
- What happens if the hallux rotates into a vaglus position in the frontal plane? now moves in both sagittal and transverse
- What movement occurs now to the hallux now? retrograde buckling
- What impact might this have on the first metatarsal? increase ‘bunion’ deformity
traditional algorithm (basic)
small IMA
- soft tissue or distal (metaphyseal) osteotomy
moderate IMA
- metaphyseal or diaphyseal
- w/ or w/o soft tissue
large IMA
- diaphyseal or base
- possibly w/ head osteotomy alos
- w/ or w/o soft tissue
following values are abnormal, address with: ****
PASA
DASA
HIA (hallux interphalangeal angle)
PASA = reverdin or “rotational” (in transverse plane) osteotomy
DASA = proximal akin
HIA = distal akin
indications for bunion surgery
- Symptoms that interfere with normal daily activities
- Severe or rapidly developing deformity in young patients
- Skin breakdown and ulceration
- NOT a cosmetic procedure??
traditional bunion incision
- Dorsal-medial incision
- Medial and adjacent to the extensor hallucis longus
- Subcutaneous dissection for extracapsular lateral release
- Dorsal capsulotomy
- Medial capsuloraphy in the subcutaneous pouch
review first MPJ anatomy
contraindications to isolated soft tissue procedures
- Degenerative joint changes
- Restricted ROM at MTPJ
- Pain with joint stress
- A track-bound joint
- Congruous MTPJ
- IM angle > 12
- HAA > 40
lateral release - why? what?
- Perform to realign the first metatarsal head over the sesamoids and release contracture (Is this needed if sesamoids are actually where they should be relative to the crista?)
- Includes release of:
- conjoined adductor hallucis tendon,
- deep transverse intermetatarsal ligament
- lateral collateral ligament (vertical capsulotomy)
- fibular suspensory ligament (fibular sesamoid release)
bump n’ run
silver
describe proximal akin
DASA
distal akin
HIA
describe reverdin
- Osteotomy in metaphyseal are of the 1st metatarsal area of the 1st metatarsal head for correction of abnormal PASA
- Lateral cortex is left intact
- Distal cut is made first, parallel to joint surface
- Proximal cut is made second, perpendicular to long axis of 1st metatarsal
small IM angle and PASA
reverdin - laird will address both
horizontal V osteotomy
Austin
apex in central metatarsal head
angle of apex is 60 degrees *
picture of biplane Austin (
if I want to plantarflex and lengthen 1st met, where should the pin (axis guide) be?
- always going in medial to lateral
- to plantarflex(+): dorsalmedial to plantarlateral
- to lengthen (++): proximal dorsalmedial to distal plantarlateral
scarf
“z” osteotomy in diaphyseal and metaphyseal bone
an inverted scarf (not pictured) will be 1.6 times stronger than traditonal (pictured)
hinge axis concept
not test questio but you need to know
- Hinge axis can be altered to create desired dorsiflexion or plantarflexion of distal segment
- Plantarflexion - Superior pole of axis angled lateral creating a dorsal-medial hinge
- Dorsiflexion - Superior pole of axis angled medial creating a plantar-medial hinge
you have a short met, what procedure should you use?
crescentic
loose the least amount of lenght with osteotomy
prinicples behind juvenill HAV with open physis (epiphysiodesis)
- Arrest of the lateral portion of the physis
- Medial portion open and continues to grow
- Leads to lateral movement of the 1st metatarsal, closing down the IM 1-2.
- Timing is critical
- Adequate ossification of the epiphysis needed to secure fixation
- Enough growth remaining needed to result in IMA reduction
- Somewhat of a guess as to when and how much
- Must address other pathologies
- Flat foot
- Metadductus
traditionally cited causes
- Overcorrection of IMA
- “Staking” of the metatarsal head
- Over zealous medial capsuloraphy
- Over aggressive lateral release
- Removal of the fibular sesamoid
- These factors are recognized as technical factors associated with Hallux Varus but, maybe it is our basic procedure philosophy that is the cause and not the execution
- NOT BANDAGING
