TAR Work-Up (indications, physical exam, etc.)
Patients with prior ankle arthrodesis can be converted to implant arthroplasty when significant symptoms develop in adjacent and/or distant joints or there is malposition or nonunion of the fusion.
True or False
Previous reports of take down fusions and general consensus suggest that the distal fibula does not need to be intact for a successful durable implantation
FALSE
Previous reports of take down fusions and general consensus suggest that the distal fibula needs to be intact for a successful durable implantation
Describe the anterior approach incision placement
Long curvilinear incision following course of EHL. The incision should be long enough to reduce tension on incision margins and adequately expose the distal tibia and extend to the talonavicular joint.
The _______ was FDA cleared in 2012. It is a bicondylar, conical articulation designed to allow for more normal integration with muscular and tendon function, with two rail tibial and talar fixation oriented in the coronal plane to stabilize implant against normal joint motion. There is no size interchangeability between talar and tibial components. Metal components have a specialized metallic porous surface that is spot welded with cement. The device is placed from lateral and involves a fibular osteotomy. A specialized frame is needed to guide instrumentation.
Semi conforming articulation is designed to limit point loading from varus/valgus stress.
The ZIMMER BIOMET TRABECULAR METAL TOTAL ANKLE was FDA cleared in 2012. It is a bicondylar, conical articulation designed to allow for more normal integration with muscular and tendon function, with two rail tibial and talar fixation oriented in the coronal plane to stabilize implant against normal joint motion. There is no size interchangeability between talar and tibial components. Metal components have a specialized metallic porous surface that is spot welded with cement. The device is placed from lateral and involves a fibular osteotomy. A specialized frame is needed to guide instrumentation.
Semi conforming articulation is designed to limit point loading from varus/valgus stress.
Tibial component: Sizes 1-6 tibia.
Talar component: Sizes 1-6. Curved bone-implant interface of the talar component designed to minimize subsidence.
Bearing: Highly cross-linked polyethylene bearing surface to reduce volumetric wear. Three thicknesses of poly are available—highly cross-linked poly, designed to reduce surface wear and subsurface fatigue.
Patient-specific guides: No.
The consequence of loss of one of the three major pedal vessels in TAR has not been determined but in all likelihood is proportionate to the degree of overall perfusion, collateral circulation, and degree of anastomotic compensation. Most commonly, the _____ artery is compromised during the anterior exposure.
The consequence of loss of one of the three major pedal vessels in TAR has not been determined but in all likelihood is proportionate to the degree of overall perfusion, collateral circulation, and degree of anastomotic compensation. Most commonly, the dorsalis pedis artery is compromised during the exposure.
Conservative management of wound dehiscence (name one way to manage it)
Parenteral or oral antibiotics
Local wound care
Negative pressure devices
As in any total joint procedure, patients should be screened for the possibility of ______ in the oral cavity, (poor dentition), genitourinary tract, skin ulcerations, paronychia, folliculitis, or the pulmonary system
As in any total joint procedure, patients should be screened for the possibility of remote infection in the oral cavity, (poor dentition), genitourinary tract, skin ulcerations, paronychia, folliculitis, or the pulmonary system
In an anterior approach, which anatomical structure(s) is/are retracted laterally and which anatomical structure(s) is/are retracted medially?
Retract EHL and neurovascular bundle laterally and tibialis anterior medially while preserving sheath
_____was introduced to the U.S. market in 2013. While it has the same bearing interface as the INBONE II, its fixed bearing design overall is more compact requiring less bone excision. It has a horizontal axis bicondylar design. Therefore, there are no left or right components. Since it has the same joint profile as the INBONE II, the system can accept the INBONE talus, which is a flat cut design.
INFINITY TOTAL ANKLE SYSTEM was introduced to the U.S. market in 2013. While it has the same bearing interface as the INBONE II, its fixed bearing design overall is more compact requiring less bone excision. It has a horizontal axis bicondylar design. Therefore, there are no left or right components. Since it has the same joint profile as the INBONE II, the system can accept the INBONE talus, which is a flat cut design.
Tibial component: 5-mm-thick titanium with capture system for attaching polyethylene. Grit blast finish on superior surface with three angulated pegs. Size range 1-5 with size 3-5 in standard and long tray versions.
Talar component: There are 5 sizes. Cobal chrome resurfacing design with chamfer cuts open design with no sidewalls. Inferior surface features Ti plasma spray with two-angled pegs.
Flat cut option: Yes (INBONE).
Bearing: 2-mm increments. Polyethylene is non–cross-linked. It can accommodate same size components or one size down on talus.
Patient-specific guides: Yes.
True or False
Tibial subsidence is more common than on the talar side.
FALSE
Talar subsidence is more common than on the tibial side.
Management of intraoperative fracture of medial malleolus
Immediate stabilization with internal fixation is recommended to prevent further displacement and distortion of the bone void that will accommodate the prosthesis. Usually simple and conventional fixatives can be utilized according to the fracture pattern.
In higher-risk patients, percutaneous placement of a Kirschner wire or screw along the malleoli and away from planned saw cuts can have protective value during tibial preparation
Name 3 indications for a Total Ankle Replacement
Patients with:
End-stage symptomatic ankle arthropathy
Good bone stock
Normal vascular status
Good hindfoot alignment
Sufficient collateral ligament function
Moderate to light work or activity demands
Coexistent midfoot and hindfoot arthrosis
Bilateral arthritic ankles
Inflammatory arthropathy
Symptomatic ankle arthrodesis or nonunion of ankle fusion
Name 2 ancillary procedures for a TAR with a varus deformity.
Calcaneal osteotomy
STJ arthrodesis
If first ray is excessively rigid: DFWO
Severe cavovarus: Soft tissue release or TN arthrodesis
Also, transfer of the posterior tibial tendon to the peroneus brevis is a powerful technique to rebalance the ankle
______ was FDA cleared in 2016. It is a bicondylar design with angulated joint axis. The poly layer inserts to the tibial plate via a shallow dovetail feature. Talar sizes can be downsized by one size from the tibial size used.
CADENCE TOTAL ANKLE SYSTEM was FDA cleared in 2016. It is a bicondylar design with angulated joint axis. The poly layer inserts to the tibial plate via a shallow dovetail feature. Talar sizes can be downsized by one size from the tibial size used.
Tibial component: Titanium alloy with two angulated pegs anteriorly and a posterior angulated tab. Nine sizes left and right specific
Talar component: There are 5 sizes. Cobalt chrome resurfacing design with chamfer cuts open design with no sidewalls. Inferior surface features Ti plasma spray with two-angled pegs.
Bearing: Highly cross-links (UHMWPE), five sizes, seven heights left and right specific, neutral anterior and posterior biased options (6-12 mm thick poly, by 1-mm increments)
Patient-specific guides: No
Polyethylene wear can lead to activation of macrophages, which in turn can lead to _______, ______, and _______. (name one thing it can lead to)
Polyethylene wear can lead to activation of macrophages, which in turn can lead to periprosthetic osteolysis, ballooning lysis, and component loosening.
The timing of reimplantation should be governed by a reasonable assurance that the infection has been eradicated.
Although there is some debate regarding the safe threshold for reimplantation, in most cases, this period of time is ___ months or more.
Although there is some debate regarding the safe threshold for reimplantation, in most cases, this period of time is 6 months or more.
Name 3 relative contraindications for a Total Ankle Replacement
Previous severe trauma (ie, open fracture of ankle, talar body dislocation, segmental bone loss)
AVN talus 25%-75% of body
Severe osteopenia/osteoporosis
Dependence on immunosuppressive medications
Elevated Hbg A1c levels in diabetic patients
Demanding sport or work activities
Obesity (especially with relatively small ankle sizes)
Younger patients (<40 years) with intact hindfoot joint function
Name 2 ancillary procedures for a TAR with a valgus deformity.
Equinus release
Tendon transfer
Ligament reconstruction
Calcaneal osteotomy
Hindfoot arthrodesis
_____ is a mobile-bearing prosthesis that was introduced to the U.S. market in 2010. It went through 9 years of formal U.S. clinical trials before becoming approved by FDA. It is the only ankle prosthesis that has gone through FDA type 3 trials. It can be placed on-label uncemented. It is one of the implants with a cylindrical design. It has been used for over 40 years primarily in Europe.
STAR TOTAL ANKLE REPLACEMENT is a mobile-bearing prosthesis that was introduced to the U.S. market in 2010. It went through 9 years of formal U.S. clinical trials before becoming approved by FDA. It is the only ankle prosthesis that has gone through FDA type 3 trials. It can be placed on-label uncemented. It is one of the implants with a cylindrical design. It has been used for over 40 years primarily in Europe.
Tibial component: Flat glide plate that is 3 mm thick with two barrels centrally located on superior surface for osseous fixation. It comes in four sizes: small, medium, large, and extra large. It ranges from 30 to 45 mm in AP depth. There is no left or right specificity to the tibial side.
Talar component: Resurfacing design with near cylindrical shape. Enclosed cap design with recessed chamfered surfaces and a central keel. The talar components come in four sizes: large, medium, small, and extra small. There is left and right specificity to the talar side.
Flat cut option: No.
Bearing: Mobile bearing with fixed area of coverage between all components. Medium cross-linked polyethylene in 1-mm increments. It has a flat tibial surface. The talar surface has a central groove that fits over the talar crest to keep poly centralized on the talus. Superior surface can function with 3 degrees of freedom.
Patient-specific guides: No.
Name 2 adverse events that can compromise TAR outcome.
Subsidence
Aseptic loosening
Deep infection
Osteolysis
Chronic pain
Technical error
Malalignment
Implant failure
Wound necrosis
When the presentation of infection occurs beyond the 30-day postoperative period or symptoms have persisted for more than 3 weeks, the treatment involves:
When the presentation of infection occurs beyond the 30-day postoperative period or symptoms have persisted for more than 3 weeks, the treatment involves removal of all of the components and vigorous debridement of the entire joint.
A cement block insertion will provide high concentrations of antibiotics and impart some stability of the joint. Repeat irrigation and debridement may be necessary in severe cases.
The volume of the block of cement should approximate that of the combined components, such that the joint space is maintained for future reconstruction
Name 3 absolute contraindications for a Total Ankle Replacement
Charcot arthropathy
Active or recent infection
AVN talus (>75% of talar body)
Severe uncorrectable deformity
Progressive sensory or motor dysfunction of lower leg
Open ulceration of lower extremity
Dysvascular disease
As the ankle loses the ability to retain the talus, the talar sagittal position can drift anterior or posterior. This is called _____.
Generally, ______ will self-correct with removal of distal tibial resected bone. However, in excessive deformities, the gutters may have osteophytes and adapted bone contour that can inhibit relocation of the talus. Remodeling of the gutters is then necessary to allow relocation of the talus.
As the ankle loses the ability to retain the talus, the talar sagittal position can drift anterior or posterior (talolisthesis).
Generally, talolisthesis will self-correct with removal of distal tibial resected bone. However, in excessive deformities, the gutters may have osteophytes and adapted bone contour that can inhibit relocation of the talus. Remodeling of the gutters is then necessary to allow relocation of the talus.
Name 2 revision TAR designs
SALTO TALARIS XT
INBONE TOTAL ANKLE SYSTEM
INVISION TAR PROSTHESIS
Name 1 TAR intra-op complication and 2 post-op complications
INTRAOPERATIVE
Artery laceration: dorsalis pedis
Component malalignment/mis-sizing
Fracture: malleolar
Nerve lacerations
Tendon laceration: PT
Tendon laceration: FDL
Tendon laceration: EHL
Uncorrected deformity
POSTOPERATIVE
Component dislocation: mobile bearing
Component fracture
Component subsidence/aseptic loosening
Fracture: fibular stress
Fracture: talus
Heterotopic bone formation
Infection: deep
Infection: superficial
Ligament insufficiency/edge loading
Nerve complications: CRPS
Nerve complications: incisional entrapment
Nerve complications: tarsal tunnel syndrome
Osteolysis/radiolucency
Pain with stiffness
Skin fistula
Tendon necrosis: anterior tibial
Tendonitis
Vascular compromise
Venous thrombotic event
Wound healing delay
Double Jeopardy
Name 2 surgical techniques for treatment of gutter impingement.
Regardless of the surgical technique, sufficient space should be created such that _______ can be passed freely from the anterior capsule to the posterior capsule.
Open and arthroscopic debridement has been reported to decompress the gutters.
Regardless of the surgical technique, sufficient space should be created such that 4.0 burr or instrument can be passed freely from the anterior capsule to the posterior capsule.