Summary System is intended for internal fixation for combined ankle and subtalar arthrodesis, with design intent to allow independent stabilization of the ankle and subtalar joints Incorporates a staged compression mechanism (StageLock®) enabling controlled, internal, independent compression at the tibiotalar joint (Stage 1) and talocalcaneal joint (Stage 2), with up to 0-5mm of internal compression at each interface Uses a targeting workflow that can include an optional Primary Jig to guide distal-to-proximal starter wire placement and a radiolucent carbon fiber outrigger to support screw targeting and nail rotation checks Indications Indications failed ankle replacement arthritis of ankle and subtalar joint correcting neuromuscular imbalance of hindfoot where bone fusion is required revision of ankle and/or subtalar fusion revision of tibiotalocalcaneal (TTC) fusion talar avascular necrosis (AVN) charcot trauma neuropathy pseudoarthrosis rheumatoid arthritis Contraindications any active infection soft tissue defects, unless concomitant procedures planned foreign body sensitivity to implant materials patients with psychiatric or neurological conditions who are unwilling or incapable of adhering to post-operative care instructions Biological Materials Nail type II anodized titanium alloy Anatomy Osteology tibia intramedullary canal size and tibial metaphyseal flare influence nail diameter selection and reaming strategy talus central talar body/neck trajectory is key for distal-to-proximal wire path and for talar screw purchase limited talar bone stock shifts strategy toward earlier talar screw targeting (optional pathway) calcaneus plantar entry corridor requires centered tuberosity starting point and awareness of plantar cortex when choosing nail depth and distal screw targets hindfoot alignment reduce and align the hindfoot directly beneath the tibia position the foot so it would rest flat on the ground across all planes set neutral or slight external rotation referencing the tibial tuberosity Muscles achilles–gastrocsoleus equinus management may be required to obtain plantigrade alignment and avoid excessive distal plantar translation during reduction peroneals relevant for lateral exposure and subtalar access; may require protection/retraction depending on incision placement tibialis posterior/anterior deformity drivers in varus/valgus and midfoot compensation; balance considerations after TTC fusion EHL anterior approach is centered over EHL, which is retracted laterally Ligaments lateral hindfoot/ankle ligaments lateral approach includes transection of distal ligaments during fibular mobilization/removal capsuloligamentous restraints release/resection tailored to deformity correction and exposure; not specified in provided manufacturer materials Nerves plantar entry nearby neurovascular bundles are at risk during plantar incision and dissection; blunt dissection to plantar calcaneus is recommended to avoid disruption anterior approach superficial peroneal nerve is at risk distally avoid injury during exposure general practice consider medial/lateral plantar nerve/artery course when planning plantar entry and retractors; not specified in provided manufacturer materials Blood supply talus tenuous vascularity and prior trauma/surgery increase AVN and nonunion risk; optimize soft tissue handling and fixation strategy accordingly fusion biology preserve soft tissue envelopes and minimize devascularizing dissection around talus/calcaneus when possible Preoperative Planning Imaging x-ray tibia-fibula films with AP and lateral views used to measure the intramedullary canal and estimate nail diameter evaluate coronal/sagittal alignment goals, bone loss, talar morphology, calcaneal tuberosity trajectory, and prior hardware/stress risers CT helpful for defining talar/calcaneal bone stock, nonunion planes, Charcot fragmentation, and hardware mapping in revision cases Planning considerations plan to bring the hindfoot directly beneath the tibia and achieve a plantigrade foot across planes bone stock limited talar bone stock and an intact distal fibula may drive the talar screw first / anterior approach alternative and additional screw-path checks relative to the fibula nail length plan for the proximal nail end to be at least 50mm past potential stress risers including fractures, non-union sites, bone resection locations, and pre-existing screw holes Surgical Approach Approach selection principles aim to use existing incisions when possible generally, the most effective approach is the one the surgeon is most experienced with Lateral approach incision upper limit at least 2cm above the tibial plafond; continue over the fibula curving anteriorly at the tip of the fibula toward the base of the 4th metatarsal exposure fibula divided proximal to tibial plafond; fibula mobilized with distal ligaments transected; fibula removed to allow access to the subtalar joint graft cancellous bone can be harvested from the resected fibula and utilized as bone graft adjunct separate anteromedial approach may be required to prepare the medial malleolus Anterior approach incision anterior longitudinal incision approximately 1cm lateral to the tibial crest, centered over the EHL tendon interval retract EHL laterally to allow access; perform capsulotomy to expose the tibiotalar joint including medial and lateral gutters nerve pearl take care distally to avoid injury to the superficial peroneal nerve subtalar exposure separate lateral incision just anterior to the peroneal tendons, beginning at the tip of the fibula and extending approximately 4-5cm Technique Workflow patient positioning and room setup positioning options login to view 1 more bullet table and draping login to view 3 more bullets fluoroscopy login to view 1 more bullet fusion site preparation ankle joint login to view 4 more bullets subtalar joint login to view 2 more bullets alignment and rotation login to view 3 more bullets tip login to view 1 more bullet starter wire placement primary jig technique login to view 11 more bullets freehand alternative login to view 4 more bullets entry reaming exposure login to view 2 more bullets primary reaming login to view 2 more bullets secondary reaming login to view 1 more bullet fluoroscopy check login to view 1 more bullet entry reaming and modular/flexible reaming exchange to olive rod login to view 3 more bullets modular reaming sequence login to view 3 more bullets final ream guidance login to view 1 more bullet reaming technique pearl login to view 1 more bullet rod management login to view 1 more bullet instrumentation setup and checks outrigger assembly login to view 7 more bullets outrigger alignment check login to view 2 more bullets outrigger rotation login to view 3 more bullets gold clip removal login to view 3 more bullets nail selection and insertion insertion prerequisites login to view 1 more bullet insertion over rod login to view 1 more bullet impaction login to view 3 more bullets depth target login to view 1 more bullet precaution login to view 1 more bullet mallet precaution login to view 1 more bullet screw insertion sequence reaming rod removal login to view 1 more bullet nail rotation check login to view 2 more bullets proximal tibial screws login to view 6 more bullets StageLock® compression options option 1 full internal compression login to view 15 more bullets option 2 hybrid internal compression login to view 8 more bullets option 3 full external or no compression login to view 9 more bullets compression precaution login to view 1 more bullet P/A screw insertion setup: rotate outrigger posterior; align drill guide construct in “PA 30 DEG” drilling and insertion: drill bicortically posterior-to-anterior using the P/A step drill from the calcaneus to the talus; measure depth; insert the 6mm screw via guide tube until the driver laser mark meets the end of the guide tube or the screw head is snug against the calcaneus end cap insertion and purpose insert an end cap after P/A screw placement and outrigger removal login to view 1 more bullet attach end cap to the self retaining driver, insert into the distal end of the nail, and secure by rotating clockwise if an end cap is not used, bony ingrowth may occur, potentially increasing difficulty of removal implant removal overview remove the end cap, the 5mm screws, and the 6mm P/A screw attach the extraction adaptor to the distal end of the nail by threading with the larger “top hat,” then tighten by turning the smaller “top hat” thread slap hammer into the extraction adaptor and gently withdraw the nail Optional pathway talar screw first / anterior approach alternative technique rationale login to view 4 more bullets wire/jig positioning login to view 4 more bullets planning checks login to view 2 more bullets execution login to view 4 more bullets Technical specifications Nail constructed from Type II anodized titanium alloy diameters 10.0mm, 11.0mm, 12.0mm available lengths 190mm, 220mm, 250mm base/distal diameter distal diameter of each nail is 12.5mm only the proximal diameter of the nail is changing Instrumentation primary jig optional instrument to guide initial placement of the 3.2mm starter wire distal-to-proximal designed to reduce the number of starter wire attempts includes an alignment “fork” that stabilizes wire alignment and is visible under fluoroscopy carbon fiber/PEEK polymer composite material outrigger carbon fiber outrigger jig is radiolucent and allows rotation of the radial arm through medial, posterior, and lateral positions includes a locking wheel to rotate around the nail axis and then lock physical outrigger is not color-coded impactor deflects the olive reaming rod during nail insertion to allow axial force to be applied with a mallet without contacting the rod Screws Screw families SUCCESSION® M/L Screw Options Diameter Length 5.0mm 22mm 5.0mm 24mm 5.0mm 26mm 5.0mm 28mm 5.0mm 30mm 5.0mm 32mm 5.0mm 34mm 5.0mm 36mm 5.0mm 38mm 5.0mm 40mm 5.0mm 42mm 5.0mm 44mm 5.0mm 46mm 5.0mm 50mm SUCCESSION® P/A Screw Options Diameter Length 6.0mm 85mm 6.0mm 90mm 6.0mm 95mm 6.0mm 100mm 6.0mm 105mm 6.0mm 110mm Design rationale statements each screw is designed with an optimized core diameter to deliver increased strength in critical load-bearing areas 6mm P/A screws are described as providing rigid fixation in the calcaneus and across the subtalar joint Pearls & Pitfalls Pearls use existing incisions when possible, and default to the approach you are most experienced with preserve the medial malleolus as a medial buttress and consider a separate anteromedial incision over the medial gutter for preparation confirm distal-to-proximal starter wire trajectory on lateral fluoroscopy and maintain centering on AP, lateral, and calcaneal axial views through calcaneus, talus, and tibia during 13.5mm secondary reaming, confirm on lateral fluoroscopy that the reamer contacts tibial metaphyseal bone and matches intended nail countersink oversize the final modular reamer diameter by 1.0mm relative to the chosen nail diameter, and consider selecting a nail 1.0mm less than the diameter reamed to reduce impaction and fracture risk keep the reamer in forward gear for all reaming operations, even when withdrawing remove the gold clip prior to nail insertion recess the nail end 5-10mm within the calcaneus before screw placement remove the olive tipped reaming rod before drilling the first screw, and confirm the reaming rod is removed before proximal tibial drilling to prevent clashes use the short and long 4/5mm drills as intended to improve rotational stability and avoid hand interference use manual, not power, application when applying internal compression at Stage 1 and Stage 2 do not remove the Stage 2 driver until the locking calcaneus screw step is completed and subtalar compression is satisfactory place an end cap after P/A screw placement and outrigger removal to inhibit bony ingrowth and add stability to the Stage 2 mechanism Pitfalls malreduction of the hindfoot (varus/valgus/rotation) from incomplete joint preparation or failure to bring the hindfoot beneath the tibia (pdf + general) excessive bone resection during joint preparation leading to limb shortening or inadequate talar fixation plantar entry without blunt dissection to plantar calcaneus risking injury to nearby neurovascular bundles failure to remove the gold clip prior to nail insertion inadequate reaming prompting vigorous hammering; avoid hammering the carbon fiber outrigger arm, locking wheel, or nail draw bolt, and treat hammering as a reaming problem drilling with the reaming rod still in the nail causing instrument clashes poor nail rotation control leading to suboptimal P/A trajectory and compromised talus purchase for the P/A screw plunging through the far tibial cortex with the tapered drill bit, potentially compromising far cortex purchase disengaging the driver before the screw is fully seated, risking incomplete seating and fixation loss using power tools to apply internal compression, risking loss of control or mechanism damage removing the Stage 2 driver before the locking calcaneus screw step is completed, risking loss of subtalar compression omitting an end cap, allowing bony ingrowth that can increase difficulty of removal insufficient tightening of outrigger components leading to misalignment, or over-tightening the external compressor to the slotted stage talar screw path not evaluated relative to an intact distal fibula in anterior exposure, risking cortical breach while trying to obtain talus fixation