La Porta Great Toe Implant

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La Porta Great Toe Implant

• Dr. Corolinda Helu
• Dr. Sherri Nazarian
• New York Community Hospital
• Brooklyn, NY

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Description

• Futura Biomedical
• Hinged MPJ implant
• Total joint replacement
• UltraSil silicone elastomer

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Indications

• Hallux limitus or rigidus
• Painful RA
• Hallux abductus or abducto valgus associated w/
  arthritis
• Unstable of painful joint from previous sx

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Contraindications

• Compromised neurovascular status
• Severe bone demineralization
• Inadequate bone or skin
• Pre- existing joint infection

• Poorly motivated or psychologically inadequate
  patient

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Design Advantages

• 15 degree angled MT stem in sagittal plane which
  compensates for MT declination No
  compromise on ROM or pre- stressing the implant

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Design Advantages Cont.

• 10 degree transverse plane angulation of MT stem
  thus resulting in normal hallux abductus position
  ----gt Right and Left implants

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Neutral Design

• Straight MT stem in sagittal plane
  
• Indicated for hallux rigidus and limitus
• Angled MT stem in transverse plane
• Right and Left apply

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Design Advantages Cont.

• Both MT and phalangeal stems are rectangular in
  shape to reduce possibility of implant rotation
• Hinge produces 60 degree flexion before
  intramedullary gliding of stem occurs

• No permanent fixation required so equal
  distribution of forces occur around the implant
• Pre sterilized

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Other Options

• Keller- shortens toe may cause stiffness
• Arthrodesis- will not be successful in women (
  men) who enjoy different dress shoes
• Titanium hemi great toe implant is not indicated
  in RA and very active patients

• Swanson total implant is not angled in the
  anatomic form as LaPortas implant has been
  designed and therefore does not allow for PASA
  correction

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Implant Handling Recommendations

• Avoid contact w/ gowns, drapes, gloves, sponges
  (keep handling to minimum to avoid FB reactions)
• Use blunt instruments to handle
• Immerse implant in sterile antibiotic or saline
  solution

• Avoid trimming of implant. If distal phalngeal
  stem needs shortening, rinse to remove any free
  particles that may have been created

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Complications

• Infection or painful swollen or inflamed implant
  site
• Fracture of stem or articular surface
• Loosening of prosthesis/ further sx
• Allergic reaction to implant material

• Migration of particle wear causing bodily
  response (macrophages/ fibroblasts)
• RSD
• Stiffness/ Pain
• Sclerotic reaction

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Surgical Procudure

• Dorsomedial curvilinear skin incision over 1st
  MPJ
• Sharp and blunt
• Free sub Q tissue from capsule
• Preserve EHL and hood ligament

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Surgical Approach

• EHB, conjoined adductor tendon and lateral
  capsule sectioned prn clinical deformity
• Capsular approach dicated by deformity and
  surgeon preference

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Surgical Approach

• Complete exposure of MT head and base of proximal
  phalanx
• Collateral and sesamoidal ligaments freed from MT
• Remove base of proximal phalanx w/ power saw at
  right angles to shaft

• Consider both sagittal and transverse plane
• FHB may detach so consider flexor tenodesis-
  maintain functional stability of joint
• Distal MT head resected parallel to phalanx stump

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Careful

• Minimum amount of MT head removed/ Cuts should
  not interfere w/ sesamoid apparatus

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Setting the Implant

• Pilot hole made in intramedullary canal of MT and
  phalanx
• Canal reamed at the same angle of chosen implant
  using a specific rasp to permit exact fit of
  appropriate implant stem

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Choosing the prosthesis

• Depends on anatomical requirements of the joint
  Transverse plane angle MT declination
  angle Size
• Collar of hinge should rest on transected
  cortical bone

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Pre- Closure

• Often necessary to sacrifice the EHB and lengthen
  the EHL tendon (Z- plasty)
• Loose and unrestrictive ROM must be obtained
  before closure

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Closure

• Joint capsule reapproximated and sutured covering
  implant completely
• Superficial facia and skin approximated and
  sutured
• Dry sterile semi- compression dressing

• Splint toe in desired corrected position

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Post Operative Care

• Limited ambulation may begin post-op
• Surgical shoe
• Elevated foot and leg during rest period
• Remove sutures in 14 days
• Early active and passive ROM exercises

• Normal footwear when function and edema permit

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Pre-op Xrays
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Post-op Xrays
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