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 login to view 1 more bullet talus login to view 2 more bullets calcaneus login to view 1 more bullet hindfoot alignment login to view 3 more bullets Muscles achilles–gastrocsoleus login to view 1 more bullet peroneals login to view 1 more bullet tibialis posterior/anterior login to view 1 more bullet EHL login to view 1 more bullet Ligaments lateral hindfoot/ankle ligaments login to view 1 more bullet capsuloligamentous restraints login to view 1 more bullet Nerves plantar entry login to view 1 more bullet anterior approach login to view 2 more bullets general practice login to view 1 more bullet Blood supply talus login to view 1 more bullet fusion biology login to view 1 more bullet Preoperative Planning Imaging x-ray login to view 2 more bullets CT login to view 1 more bullet Planning considerations plan to bring the hindfoot directly beneath the tibia and achieve a plantigrade foot across planes bone stock login to view 1 more bullet nail length login to view 1 more bullet 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 login to view 1 more bullet exposure login to view 1 more bullet graft login to view 1 more bullet adjunct login to view 1 more bullet Anterior approach incision login to view 1 more bullet interval login to view 1 more bullet nerve pearl login to view 1 more bullet subtalar exposure login to view 1 more bullet Technique Workflow patient positioning and room setup login to view 8 more bullets fusion site preparation login to view 14 more bullets starter wire placement login to view 17 more bullets entry reaming login to view 10 more bullets entry reaming and modular/flexible reaming login to view 14 more bullets instrumentation setup and checks login to view 19 more bullets nail selection and insertion login to view 14 more bullets screw insertion sequence login to view 12 more bullets StageLock® compression options login to view 37 more bullets P/A screw insertion login to view 2 more bullets end cap insertion and purpose login to view 4 more bullets implant removal overview login to view 3 more bullets Optional pathway talar screw first / anterior approach alternative technique login to view 18 more bullets Technical specifications Nail constructed from Type II anodized titanium alloy diameters login to view 1 more bullet available lengths login to view 1 more bullet base/distal diameter login to view 2 more bullets Instrumentation primary jig login to view 4 more bullets outrigger login to view 3 more bullets impactor login to view 1 more bullet 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