Pearls & Pitfalls Orthobullets Technique Guides cover information that is "not testable" on ABOS Part I Preparation check skin quality, soft tissue envelope, ankle and subtalar range of motion, degree of tibiotalar and subtalar arthritis, amount of deformity Positioning standard OR table with radiolucent table end foot 3-4” off end of table for posterior calcaneus screws c-arm from contralateral side Approach lateral approach to ankle directly lateral to fibula with transfibular osteotomy to access joint Joint Preparation remove tibiotalar and subtalar cartilage bony prep with kwire drill holes and osteotomes Guidewire Insertion start point is center of talus and distal tibia on AP and Lat xrays Reaming size 9mm reamer then ream 1.0-1.5mm above size of final nail Nail Insertion insert nail over guidewire and bury so that talar interlocking hole is in body of talus Interlocking Screws targeting guides to place screws in order talus, proximal tibia (x2), and calcaneus (x2) screws, add endcap Postoperative non-weight bearing in splint, crutches for ambulation evaluate fusion mass on serial xrays, range of motion exercises and advance weight-bearing at 2-3mo post-op in CAM boot Planning & Preparation Extremity Exam check soft tissue envelope, ankle and subtalar range of motion, degree of tibiotalar and subtalar arthritis, amount of deformity document distal neurovascular status and associated comorbidities Imaging weight bearing AP/Lat/Mortise views of ankle evaluate joint space narrowing, subchondral sclerosis and cysts, angular deformity of tibiotalar and subtalar joints post-traumatic arthritis is most common etiology of ankle and subtalar arthritis (>2/3 cases) many cases have varus/valgus deformity Equipment & Positioning Equipment hindfoot arthrodesis intramedullary nailing system (Stryker T2 Hindfoot Nail System) 4.0mm cancellous screws, 2.5mm drill (Synthes Small Fragment Set) 1.6mm kwires osteotomes ACL saw blade small fragment set (4.0mm cancellous screws) c-arm fluoroscopy standard OR table with radiolucent end Position patient supine with small bump under ipsilateral thigh, tourniquet on thigh stack of sterile towels under calf after draping foot hanging 3-4” off end of table in order to place posterior to anterior interlocking screws OR Setup and C-arm standard OR table with radiolucent end c-arm from contralateral side perpendicular to bed Approaches Lateral Approach to Ankle incision directly lateral to fibula subperiosteal dissection over anterior and posterior fibula curve slightly anterior over subtalar joint full thickness flaps identify and protect SPN Surgical Technique Approach mark out medial and lateral malleoli, tibiotalar, and subtalar joints incision with 15blade through skin along center of fibula curved slightly anterior at tibiotalar and subtalar joints only need minimal exposure of subtalar joint for preparation tenotomy through subcutaneous tissue, cauterize bleeders do not strip periosteum off of distal fibula want to keep it as vascularized as possible for bone graft at end of case subperiosteal dissection off anterior and posterior aspects of fibula if lots of scar tissue use cautery to take down clean out syndesmosis 3-4cm above tibiotalar joint with rongeur and curettes Fibular Osteotomy superolateral to inferomedial fibular osteotomy with ACL sawblade 3-4cm above tibiotalar joint finish cut with osteotome sharply dissect off fibula anteriorly and reflect posteriorly alternatively can completely remove fibula for bone graft can use hinged fibula posteriorly as vascularized graft for fusion site at end of case by fixing back into place with screws clean out remaining syndesmosis and fibrous tissue to define tibiotalar joint Joint Preparation remove tibiotalar and subtalar cartilage using burr, ostetomes, and curettes if large deformity can take large saw blade to make flat cut of distal tibia and talus (2-3mm cut) parallel to joint if unequal bone loss from distal tib or talus rather than shorten bones more with more saw cuts, add in bone graft for good bony apposition in cases of very large deformity (varus/valgus) add medial incision curved slightly anterior with 15blade take sharply down to periosteum expose anterior and posterior and take saw through medial mal for bone graft once flat cuts are made in tibiotalar joint check fluoro to line up talus in center of distal tibia so that ankle is in neutral alignment while prepping tibiotalar joint extend down to subtalar joint insert laminar spreaders and removed cartilage with curettes, osteotomes, drill with kwires to prep surface place 1-2 kwires from calcaneus through subtalar and tibiotalar joints to pin joint in place can alternatively use cross pins from proximal to distal, check on AP and Lat xrays place tibiotalar joint into 0° dorsiflexion, 5° valgus, and 5-10° external rotation on mortise Guidewire Insertion guidepin start point is in center of talus and distal tibia on AP and Lat check Harris heel view use 15blade to make 3cm incision around guidewire to accommodate reamer and nail Reaming place soft tissue protector down to bone with entry reamer 3cm into distal tibia put long ball tip guidewire though entry hole into proximal tibia check proximal extent to determine nail length measure nail length with measuring guide (typically use 200mm nail) nail lengths are 150/200/300mm length of nail should just go into diaphysis for 300mm nail you need to free hand the prox tibia interlocking screws start with size 9 reamer ream up 0.5-1.0mm with each reamer until 1.0-1.5mm above size of nail (i.e. ream 12.5 for 11mm nail) push through anterior cortex before starting reamer do not ream anterior cortex as you can blow out the starting hole check chatter from reamer feedback and diaphyseal fit on fluoro AP ream on full speed, slowly and deliberately don’t stop reamer in canal (avoids reamer head from getting stuck) Nail Insertion build nail on back table and make sure targeting guide lines up with holes in nail check sleeves for each proximal interlock hole place plastic sleeve over ball tip guidewire and exchange wire for small non-balltip guide wire insert nail over guidewire and mallet in using strikeplate advance to fracture site, check on fluoro AP/Lat insert nail fully and check that talar interlock hole is in body of talus check inferior aspect of nail on calcaneus remove guidewire before placing interlocking screws Interlocking Screws start with lateral to medial talar interlock screw use triple sleeve with 5.0mm drill measure off of drill, remove inner sleeve, and insert screw not always good feedback with screws so check on fluoro if needed to avoid overburying use Tommy bar to end of handle to switch targeting guide to medial proximal side use triple sleeve to mark appropriate length nail screw holes 150 vs 200mm 15blade stab incision to skin triple sleeve down to bone repeat steps above to insert interlock screws check feedback with screws move to distal end of nail and insert tibiotalar compression screw since proximal screws are locked in screw compresses across tibiotalar joint check compression on AP xray add black rubber sleeve close to inferior calcaneus and tighten inner turn handle to compress across subtalar joint switch targeting guide back to lateral side and drill and insert calcaneus screw lateral to medial check on fluoro move targeting guide to posterior slot and raise leg up assistant props elbow against table use triple sleeve as above for posterior to anterior calcaneus screw check on lateral xray to make sure screw is going through nail but not into calcaneocuboid joint remove all targeting guides and kwires insert endcap onto end of nail and check on fluoro endcap locks calcaneus screw into place Bone Graft add bone graft into tibiotalar joint from lateral and/or medial mal if using osteotomized fibula for vascularized bone graft can fix with 4.0mm cancellous screws Confirm Nail Position and Extremity Check take final fluoro AP/Lat of proximal, middle, and distal aspects of nail harris heel view to check calcaneus screws check limb length, rotation, and alignment Closure Irrigation & Hemostasis deflate touriniquet irrigate and cauterize peripheral bleeding vessels place hemovac drain exiting proximal and lateral Closure deep layer with 0-vicryl subcutaneous with 2-0 vicryl and skin closure with 3-0 nylon do not forget to close all interlocking screw sites (posterior heel) Dressing soft incision dressings and postmold sugartong splint for immobilization Postoperative Care Immediate Post-op non-weight bearing in splint, crutches for ambulation discharge to home on post-op day 1 after drain removed 2 Weeks wound check sutures removed place into cast or CAM boot non-weight bearing repeat xrays of ankle 8-12 Weeks xrays to evaluate fusion mass range of motion exercises to ankle in CAM boot advance weight bearing status and rehabilitation Complications Document Complications wound breakdown superficial/deep infection symptomatic hardware malunion nonunion neurovascular injury (lateral plantar nerve)