- 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
- roast homework
- 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
- 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
- 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
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