summary Proximal Tibia Epiphyseal Fractures are rare injuries seen in adolescents that may be associated with vascular injury. Diagnosis can be confirmed with plain radiographs of the knee. Treatment may be nonoperative or operative depending on the Salter-Harris classification, stability, and displacement of fracture. Epidemiology Incidence < 1% of pediatric fractures Demographics more commonly seen in children 12-14 years old Etiology Pathophysiology mechanism of injury high energy trauma varus/valgus force hyperextension Associated conditions fracture may occur as a part of a Type III tibial tubercle fracture vascular injury most common with hyperextension injuries tethering of popliteal artery (5%) peroneal nerve injury (5%) ligamentous injury seen in up to 40% of Salter-Harris type III and type IV injuries compartment syndrome (3-4%) Anatomy Physeal considerations general assumptions leg growth continues until 16 yrs in boys 14 yrs in girls growth contribution leg grows 23 mm/year, with most of that coming from the knee (15 mm/yr) proximal femur - 3 mm/yr (1/8 in) distal femur - 9 mm/yr (3/8 in) proximal tibia - 6 mm/yr (1/4 in) distal tibia - 5 mm/yr (3/16 in) closure of proximal tibial epiphysis occurs in a predictable pattern sagittal plane - posterior to anterior coronal plane - medial to lateral axial plane - posteromedial to anterolateral Ligaments medial collateral ligament superficial portion extends distal to physis to insert on medial metaphysis acts as medial buttress lateral collateral ligament inserts on proximal pole of fibula acts as lateral buttress along with fibula patellar ligament inserts on tibial tubercle acts as restraint to posterior displacement Blood supply popliteal artery distal portion lies close to posterior aspect of proximal tibia tethered to proximal tibia by firm connective tissue septa at risk of injury with displaced fractures divides into anterior tibial and posterior tibial branches beneath arch of soleus lateral inferior geniculate artery passes over popliteus, anterior to lateral head of gastrocnemius, and underneath LCL medial inferior geniculate artery passes along proximal border of popliteus, anterior to medial head of gastrocnemius, to anterior proximal tibia Classification Salter-Harris Classification Type I Fracture through the physis Mean age 12 years Usually displaced (>50%) due to buttress effect of tibial tubercle and fibula Type II Fracture through the physis and exiting through the metaphysis Mean age 14 years Usually displaced (>67%) Most common pattern is medial gapping with lateral Thurston-Holland fragment and proximal fibula fracture Type III Fracture through the physis and exiting through the epiphysis Usually tibial tubercle fractures Type IV Fracture through the physis, metaphysis and epiphysis Presentation Symptoms inability to bear weight Physical exam inspection pain and swelling tenderness along the physis may see deformity or have palpable step-off if displaced motion may see varus or valgus knee instability on exam neurovascular exam important to perform thorough neurovascular exam physis is at same level of trifurcation of vessels and there is a risk of vascular compromise with displacement Imaging Radiographs recommended views AP lateral optional views oblique varus/valgus stress but risk of injury to physis findings displacement of fracture fragments Salter-Harris classification CT indications assess fracture displacement best modality for SH III or IV fractures Treatment Nonoperative immobilization in long leg cast indications non-displaced (< 2mm) fractures stable Salter-Harris type I and type II fractures techniques reduce with traction and gentle flexion cast in slight flexion for 6 weeks outcomes redisplacement is common without fixation Operative CRPP indications unstable Salter-Harris type I and type II fractures redisplacement following closed treatment ORIF indications irreducible fractures usually due to diaphyseal periosteal flap blocking reduction displaced (> 2mm) Salter-Harris type III and type IV fractures vascular injury Techniques CRPP positioning supine on radiolucent table instrumentation crossed smooth pins transphyseal if Salter-Harris type I or type II with small Thurston-Holland fragment extraphyseal if Salter-Harris type III or IV cannulated compression screws parallel to physis useful for Salter-Harris type II with large Thurston-Holland fragment can also be used for Salter-Harris type III or IV post-op univalved or bivalved long leg cast in slight flexion for 4-6 weeks ORIF positioning supine on radiolucent table approach midline anterior longitudinal incision from inferior pole of patella to tibial tubercle consider medial approach if vascular injury instrumentation crossed smooth pins transphyseal if Salter-Harris type I or type II with small Thurston-Holland fragment extraphyseal if Salter-Harris type III or IV cannulated compression screws parallel to physis useful for Salter-Harris type II with large Thurston-Holland fragment can also be used for Salter-Harris type III or IV post-op univalved or bivalved long leg cast in slight flexion for 4-6 weeks Complications Loss of reduction Growth disturbances (25%) can lead to limb length discrepancy and/or angular deformities more common in open fractures Compartment syndrome Ligamentous instability