Pearls & Pitfalls Orthobullets Technique Guides cover information that is "not testable" on ABOS Part I Preparation check straight leg raise, patellar defects, and for open lesions evaluate fracture pattern nondisplaced, transverse, inferior pole or sleeve, vertical, marginal, osteochondral, comminuted Positioning supine on radiolucent table bump under ipsilateral thigh with thigh tourniquet c-arm from contralateral side Approach anterior approach to patella incision midline across superior and inferior poles of patella usually helpful to extend incision over patellar tendon and quad tendon Bony Preparation and Reduction sharply dissect out fracture lines and debride small and large pointed reduction clamps for reduction use small pointed reduction clamps to control fracture fragments, line them up, and then clamp with large pointed reduction clamp in center of patella out of way of hardware Fixation and Tension Band .062 kwires parallel across primary fracture lines alternatively, can place 3.5 or 4.0 cannulated screws across fracture line, travel from small fragment to large fragment and pass wire through screws 18G (#6/7) sternal wire under quadriceps and patellar tendons deep to kwires crossed over anterior patella in figure-8 pattern Tensioning and Retinacular Closure tighten tension band and cycle knee cut wires, bend wire ends down #2 Fiberwire to close medial and lateral retinacular tears if present Postoperative if fixation is solid, can allow patient to weight bear as tolerated with knee brace locked in extension begin gentle range of motion exercises to knee at 2-4 wks Planning & Preparation Extremity Exam check straight leg raise failure indicates lack of extensor mechanism note patellar defects, presence of effusion, open lesions document distal neurovascular status and associated injuries Characterize Fracture determine fracture pattern nondisplaced, transverse, inferior pole or sleeve, vertical, marginal, osteochondral, comminuted evaluate lateral xrays for patella alta and degree of fracture displacement degree of displacement correlates with degree of retinacular disruption examine for presence of bipartite patella (superolateral position) may be mistaken for patella fracture (8% of population) if extensor mechanism intact and nondisplaced or minimally displaced fracture can treat patients in knee extension brace or cast WBAT with early active ROM comminuted fractures can be treated with partial or total patellectomy with quadriceps or patellar tendon advancement Equipment & Positioning Equipment kwires (.062, .045) 18G (#6/7) sternal wire 14/16G angiocath #2 Fiberwire small fragment system cannulated screw system (ie. 3.5/4.0mm screws, 2.7/3.5mm cannulated drills) cannulated screws with tension band biomechanically superior to kwire tension band c-arm fluoroscopy Position patient supine with small bump under ipsilateral thigh thigh tourniquet OR Setup and C-arm radiolucent OR table c-arm in from contralateral side perpendicualr to bed Approaches Anterior Approach to Patella incision midline 2cm above superior pole to 2cm below inferior pole of patella full thickness subcutaneous flaps examine for retinacular tears medial and lateral Surgical Technique Approach flex knee over bump of blue towels mark out poles of patella, borders of quadriceps and patellar tendons, joint line #10-blade for skin incision anterior and midline over patella raise full thickness flaps down to bone with tenotomy scissors and knife check for medial and lateral retinacular tears Bony Preparation and Reduction sharply dissect out fracture lines with #15-blade debride and clean fracture with small rongeur, curettes, dental pic, irrigation pointed reduction clamps over fragments for reduction use small clamps to line up small fragments and large clamp placed in center of patella to hold main reduction check reduction on AP/Lat fluoro, can palpated articular surface directly if retinacular tear present Fixation and Tension Band for tension band place .062 kwires x2 parallel across primary fracture lines check with fluoro, AP and lateral drop hand towards the ground to get into center of patella and not patellofemoral joint if multiple fragments, join smaller fragments to larger ones with .045mm kwires from edge of patella or mini-fragment screws to use cannulated screws use 2.7mm cannulated drill over kwires through 1st cortex gently touch drill to 2nd cortex measure length and secure fragments with clamp to avoid rotation during 3.5mm cannulated screw insertion check lengths on fluoro drill through second cortex repeat process above for 2nd screw pass wire through screw, then cross over anterior aspect of patella and insert in second screw, then tension pass 18G (#6/7) sternal wire under quadriceps and patellar tendons deep to kwires using 14/16G angiocath with tip removed stay directly on bone and hug edges of patella to avoid soft tissue interposition create looped tension band can add 2nd wire and/or optional circumferential wire for cerclage use wire grabber and pull slack out of wires completely by crossing and pulling in opposite directions pull wires up and away from each other and put in 5-6 twists repeat above for 2nd sternal wire can add optional circumferential wire for cerclage if extra fixation needed add additional .045 kwires, back off 1cm on fluoro bend exposed end with pliers and frasier tip suction cut and bend 180° with needle driver tamp down with bone tamp and mallet check lengths on fluoro Tensioning and Retinacular Closure tighten tension band and cycle knee retighten and cut wires bend wire ends down to avoid soft tissue irritation repeat process above if circumferential cerclage wire used #2 Fiberwire to close medial and lateral retinacular tears (deep in gutters) need to use deep retractors to visualize proximal extent of retinacular tears tears propagate in oblique direction distal to proximal along medial and lateral gutters can place finger through retinaculum and palpate articular reduction prior to closure Confirm Hardware Position and Extremity Exam take final fluoro AP/Lat of patella take knee from full extension to 90° flexion check patellar tracking Closure Irrigation & Hemostasis place knee under bump and irrigate with saline bulb irrigation cauterize peripheral bleeding vessels Closure may reinforce retinacular closure with 0-vicryl subcutaneous with 2-0 vicryl skin closure with staples or nylon Dressing soft incision dressings over knee Postoperative Care Immediate Post-op if fixation solid and patient compliant, can weight bear as tolerated with knee locked in extension 2 Weeks wound check staples/sutures removed begin gentle range of motion exercises to knee at 2-4 wks repeat xrays of knee Complications Document Complications painful hardware (most common) loss of reduction (22%) malunion nonunion knee stiffness infection