Pearls & Pitfalls Orthobullets Technique Guides cover information that is "not testable" on ABOS Part I Preparation check ipsilateral femoral neck, thigh compartments, knee stability, limb length, rotation, and alignment Positioning radiolucent table and C-arm from contralateral side Approach anterior approach to intercondylar notch through anterior knee (transtendinous or peritendinous) Guidewire Insertion start point in center of intercondylar notch just superior to Blumensaat’s line Fracture Reduction pull traction at 30° angle over triangle for reduction Reaming ream 1.5mm above size of final nail Nail Insertion insert nail over guidewire Interlocking Screws targeting guide to place distal interlocking screws first check femoral neck, get perfect circles of proximal interlocking screws and insert Postoperative weight-bearing as tolerated immediate range of motion exercises to hip and knee DVT prophylaxis Planning & Preparation Extremity Exam before case need to check: ipsilateral femoral neck thigh compartments (anterior, posterior, adductor) need AP and lateral radiographs of entire femur, hip, knee CT of femoral neck 2-6% incidence of ipsilateral femoral neck fracture, often basicervical, vertical, and nondisplaced location of fracture site will indicate amount of deforming forces document distal neurovascular status Associated Injuries & Comorbidities if potential delay in definitive fixation with intramedullary nail, place distal femoral or proximal tibia traction pin with ~25lb inline traction to reduce amount of shortening no tibial traction pin if ipsilateral knee injury suspected definitive stabilization within 24 hours is associated with decreased pulmonary complications, thromboembolic events, and length of hospital stay Equipment & Positioning Equipment retrograde intramedullary nailing system c-arm fluoroscopy radiolucent flat-top table Position patient supine with feet at the end of the bed small bump under ipsilateral thigh if traction pin in place, can remove prior to prep and drape alternatively can leave in place to use for traction during case prep and drape entire leg up to iliac crest OR Setup and C-arm radiolucent OR table c-arm from contralateral side perpendicular to bed take initial AP and lateral of hip to examine femoral neck Approaches Anterior Knee plan out anterior approach to intercondylar notch through anterior knee transtendinous or parapatellar no difference in anterior knee pain Surgical Technique Approach place knee in ~30° flexion over radiolucent triangle knee flexion also prevents distal fragment from being pulled into more flexion by gastrocnemius mark out inferior pole of patella and borders of patella tendon transtendinous approach: make 2cm incision from inferior pole of patella distal through tendon tenotomy to develop paratenon layer, sharply dissect or cauterize through paratenon then patellar tendon insert self-retainers and suction out synovial fluid once in joint, remove small amount of fat pad to minimize guidepin deflection parapatellar approach: 2 cm incision along medial third of patellar tendon cut through subcutaneous tissue and retract tendon/paratenon laterally insert self retainer Guidewire Insertion guidepin start point is in center of intercondylar notch, just superior to Blumensaat’s line insert guidepin to distal metaphysis check C-arm image to ensure pin is in center of medullary canal use entry reamer with soft tissue protector remove starting pin and reamer, and place balltip guidewire in canal with T-handle place gentle bend at tip of balltip wire, manually push in to distal aspect of fracture site Fracture Reduction reduce fracture by pulling traction can use small blue towel bump to add flexion to distal segment if pulling straight inline traction on foot you will cause more flexion deformity of the distal segment due to pull of the gastrocnemius need to pull traction at 30° angle over triangle once fracture reduced, manually push guidewire past fracture site and up to lesser trochanter, check on biplanar imaging insert guidewire past lesser trochanter by 3-4cm use radiolucent ruler to measure appropriate nail length Reaming use ruler on contralateral side to measure intact femur if segmental comminution exists start with 9mm reamer, then ream up 0.5-1.0mm with consecutive reamer ream 1.5mm above size of final nail (i.e. size 12.5mm reamer head for size 11mm nail) don’t stop reamer in canal (avoids reamer head from becoming incarcerated) if eccentric reaming/wire position is seen, can place blocking screws Nail Insertion attach jig to nail on backtable and check that targeting guide lines up with holes in nail insert nail over guidewire, cover holes closest to nail handle with hand to make sure blood doesn't pressurize out of nail during insertion insert nail with jig lateral to thigh hold nail by handle, not the targeting guide, mallet or manually advance to fracture site manually advance nail past the fracture site to avoid iatrogenic comminution or development of new fracture lines possible with use of the mallet insert nail completely and seat fully lateral radiograph of the knee is the appropriate view to assess nail insertion depth remove guidewire before placing interlocking screws Interlocking Screws use targeting guide to place most distal interlock first mark skin with sleeve, incise through skin, spread down to bone with hemostat, and place trochar on bone drill bicortically through the nail leave drill bit in until screw arrives to hold nail/bone position and then place screw repeat process above for placement of other interlocking screws if indicated use attachment to remove nail jig, then take out triangle to lay leg flat check femoral neck again on C-arm obtain perfect circles of proximal interlocking screw holes ensure no rotation of the distal femur is done while getting theseviews (move the C-arm, not the leg) magnification of the fluoroscopic view can be used if desired start with most proximal interlocking hole (screw will be longer than the more distal screw) incise through skin, careful blunt spreading down to bone, especially if distal to lesser trochanter drill bit placed over center of hole, parallel to C-arm beam to measure, can use a second drill bit or depth gauge alternatively use a 34 or 36mm screw remove drill quickly and insert screw when available use locking screwdriver or place silk suture around screw head so it doesn’t get lost in soft tissues repeat above process for 2nd proximal interlocking screw Confirm Nail Position and Extremity Check raise leg up off of bed, 90° bend in knee, then take final AP and lateral radiograph of proximal, middle, and distal aspects of femur take hip through a range of motion to assess for fracture fluoroscopic evaluation is key, whether static or dynamic at the end of the procedure check limb lengths and rotation perform a knee examination under anesthesia Closure Irrigation & Hemostasis place knee under triangle and strongly flush out reamings with saline bulb irrigation irrigate until backflow is clear cauterize peripheral bleeding vessels Fascia Closure transtendinous close patellar tendon and paratenon layers with 0-vicryl subcutaneous and skin closure parapatellar close peripatellar arthrotomy, subcutaneous and skin closure Dressing soft incision dressings over knee, distal, and proximal femur Postoperative Care Immediate Postoperative Instructions weight-bearing as tolerated foley catheter out when ambulating DVT prophylaxis immediate range of motion exercises to hip and knee 2-3 Weeks wound check staples/sutures removed continue physical therapy and range of motion exercises repeat radiographs of femur Complications Document Complications post-operative knee pain heterotopic ossification delayed union, nonunion femoral nerve or artery injury (insertion of proximal interlocking screws) increased risk if screws placed inferior to lesser trochanter malrotation of femur infection hardware failure missed femoral neck fracture iatrogenic fracture (under-reaming, femoral neck fracture) iatrogenic damage to cruciate ligaments