Triple Arthrodesis, Arthroereisis, Ankle Arthroscopy



Triple Arthrodesis, Arthroereisis, Ankle Arthroscopy





TRIPLE ARTHRODESIS

Fusion of three joints in the foot:

Talonavicular joint

Talocalcaneal joint

Calcaneocuboid joint










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Fixation varies but is often with 6.5- or 7.0-mm cannulated screws for the STJ and two staples at 90° for the CC and TN joints. Hindfoot should be positioned in slight valgus position, about 5°. The body can compensate for valgus. Varus foot should be avoided at all cost; these patients end up with pain and callus formation under the lateral midfoot and forefoot. The TN fusion requires the longest time for revascularization. As a result of a triple arthrodesis, there is extra stress on the ankle joint. For this reason, the ankle joint should be free of DJD pre-op. Sliding the calcaneus posteriorly on the talus will raise the arch, and sliding the calcaneus anteriorly on the talus will lower the arch.



Incisions

Lateral incision (Ollier incision): Extends from the tip of the lateral
malleolus to the base of the 4th metatarsal, providing access to STJ and CC joint

Medial incision: Extends from medial gutter of the ankle joint to the 1st metatarsal base, providing access to TN joint and TC fixation.


Order of Joint Resection and Fixation

1. Resect MTJ (CC then TN); this allows access to the STJ.

2. Resect STJ.

3. Temporarily fixate STJ.

4. Temporarily fixate MTJ (TN then CC).

5. Fixate STJ.

6. Fixate MTJ.


Post-op

Apply Jones compression dressing immediately post-op for 2 to 3 days; casting is generally avoided because of swell.

Change dressing at 48 hours.

At 2 to 3 days, pull drain and apply a BK NWB cast.

At 3 weeks, apply D/C cast and remove sutures.

Apply removable BK NWB cast for an additional 4 weeks.

Progressive WB and PT for an additional 3 months.

Return to work 6 months.



SUBTALAR ARTHROEREISIS IMPLANTS

Subtalar joint arthroereisis implants are designed to limit subtalar joint pronation by blocking the anterior-inferior displacement of the talus. Although they are commonly referred to as subtalar joint implants, they are not inserted into the joint. They are inserted into the sinus tarsi between the posterior and middle facets of the STJ. The goal of STJ arthroereisis implants is to limit pronation and reduce heel valgus by blocking contact of the lateral talar process against the calcaneal sinus tarsi floor. They are sometimes described as an “implantable orthotic.” All subtalar implants are considered both “direct impact” and “axis-altering” implants. They are considered direct impact implants because the implants physically block the motion of the talus. This decreased motion alters the spatial orientation of the STJ axis during gait, making them “axis-altering” too.


Classifications


Intraosseous

Intraosseous implants have a stem that is fit into a hole drilled into the floor of the sinus tarsi and requires some bone resection. These intraosseous implants are falling out of favor and slowly being discontinued.


Extraosseous

Extraosseous implants are simply screwed into the sinus tarsi with no bone resection required. Extraosseous subtalar arthroereisis implants
are further divided into type I and type II.


Type I

Type I implants are inserted into the sinus portion of the sinus tarsi.


Type II

Type II implants have a narrower distal (medial) portion to the implant, allowing them to fit into both the sinus and the deeper canalis portion of the sinus tarsi.





INTRAOSSEOUS TYPE


LSI Implant (Lundeen Subtalar Implant)

Polyethylene

Intraosseous

Sgarlato labs










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STA-Peg Subtalar Implant

Polyethylene

Wright Medical










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Future ASI (Angled Subtalar Implant)

Angled intraosseous subtalar implant

Polyethylene

Wright Medical










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EXTRAOSSEOUS TYPE I


BioArch

Cannulated

Conical tapered design


Blunt thread design for limited bone impingement and irritation

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Nov 20, 2018 | Posted by in ORTHOPEDIC | Comments Off on Triple Arthrodesis, Arthroereisis, Ankle Arthroscopy
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