summary Lateral Condyle Fractures are the second most common fracture in the pediatric elbow and are characterized by a higher risk of nonunion, malunion, and AVN than other pediatric elbow fractures. Diagnosis is made with plain elbow radiographs. Treatment may be nonoperative or operative depending on the degree of articular displacement. Epidemiology Incidence 17% of all distal humerus fractures in the pediatric population 2nd most common elbow fracture after supracondylar Demographics typically occurs in patients aged 6 years Anatomic location most commonly are Salter-Harris IV fracture patterns of the lateral condyle Etiology Pathophysiology mechanism of injury pull-off theory avulsion fracture of the lateral condyle that results from the pull of the common extensor musculature push-off theory fall onto an outstretched hand causes impaction of the radial head into the lateral condyle causing fracture pathoanatomy fractures originate proximally at the posterior aspect of the distal humerus metaphysis and extend distally and anteriorly across the physis and epiphysis into the elbow joint fracture may extend medially into the trochlear groove, making the elbow unstable and prone to dislocation posteromedial elbow dislocation result of FOOSH with slight elbow flexion and adduction force rare concomitant injury pattern Anatomy Ossification centers of elbow lateral (external) epicondyle ossifies/appears at age 11 years fuses at age 12-14 years age of ossification/appearance and age of fusion are two independent events that must be differentiated Ossification center of the Elbow Years at ossification (appear on xray) Years at fusion (appear on xray) Capitellum 1 12-14 Radial head 3 14-16 Internal (medial) epicondyle 5 16-18 Trochlea 7 12-14 Olecranon 9 15-17 External (lateral) epicondyle 11 12-14 Blood Supply the brachial artery lies anteriorly in the antecubital fossa most of the blood supply of the distal humerus comes from the anastomotic vessels that course posteriorly Lateral collateral ligament remains intact and attached to lateral condyle fragment proximally and radial neck distally Classification Milch Classification Type I Fracture line is lateral to trochlear groove (less common, elbow is stable as fracture does NOT enter trochlear groove) Type II Fracture line extends medially into trochlear groove (more common, more unstable) Fracture Displacement Classification- Weiss et al Characteristics Treatment Type 1 < 2mm, indicating intact cartilaginous hinge Casting Type 2 > 2 mm < 4 displacement, intact articular cartilage on arthrogram Closed reduction and fixation Type 3 > 4 mm, articular surface disrupted on arthrogram Open reduction and fixation Presentation History fall onto an outstretched hand Symptoms location lateral elbow pain and swelling severity may be subtle if fracture is minimally displaced Physical exam inspection exam lacks the obvious deformity often seen with supracondylar fractures swelling and tenderness are usually limited to the lateral side lateral ecchymosis implies a tear in the aponeurosis of the brachioradialis and signals an unstable fracture motion may have increased pain with resisted wrist extension/flexion may feel crepitus at the fracture site Imaging Radiographs recommended views AP, lateral, and oblique views of elbow internal oblique view most accurately shows fracture displacement because fracture is posterolateral optional views contralateral elbow for comparison when ossification is not yet complete routine elbow stress views are not recommended due to pain and lack of useful information findings fracture fragment most often lies posterolateral which is best seen on internal oblique views in displaced fractures, the capitellum is laterally displaced in relation to radial head posteriorly based Thurston-Holland fragment on the lateral view Arthrogram indications minimally displaced fractures to assess cartilage surface when there is incomplete/absent epiphyseal ossification allows dynamic assessment CT scan indication rarely indicated, only if there is uncertainty as to the type of fracture MRI indication provides the ability to assess the cartilaginous integrity of the trochlea useful for operative planning of delayed or non-unions expensive require GA/sedation to perform the test arthrograms generally preferred to MRI Differential Pediatric Elbow Injury Frequency Fracture Type % elbow injuries Peak Age Requires OR Supracondylar fractures 41% 7 Majority Radial Head subluxation 28% 3 Rare Lateral condylar physeal fractures 11% 6 Majority Medial epicondylar apophyseal fracture 8% 11 Minority Radial Head and Neck fractures 5% 10 Minority Elbow dislocations 5% 13 Rare Medial condylar physeal fractures 1% 10 Rare Treatment Nonoperative long arm casting x 4-6wks indications only if < 2 mm displacement in all views medial cartilaginous hinge must remain intact technique cast with elbow at approx 90 degrees as long as swelling is mild weekly follow up and radiographs every week x first 3 weeks, including internal oblique view occasionally > 6 weeks of casting is needed Operative CRPP + 3-6 wks in above elbow cast indications fractures with 2 - 4 mm of displacement have intact articular cartilage and can be treated with CRPP open reduction and fixation + 3-6 wks in above elbow cast indications > 4mm of displacement open reduction (rather than closed) necessary to align the joint surface joint incongruity fracture non-union supracondylar osteotomy indications deformity correction in late-presenting cubitus valgus - rarely needed Techniques CRPP approach closed reduction perhaps aided by pushing the fragment anteromedially to close the gap instrumentation divergent pin configuration most stable screw considered for more rigid fixation allows early motion compresses fracture site complications pins are less stiff screw may need to be removed if crossing the physis ORIF approach anterolateral approach as blood supply comes from posteriorly soft tissue below the skin, dissection to the joint is most often already accomplished by injury avoid dissection of the posterior aspect of lateral condyle (source of vascularization) bone work directly visualize the joint reduction, at times the metaphyseal reduction may not be perfect, as fracture fragment may have plastic deformation instrumentation most fractures can be fixed with 2 percutaneous pins (3 if comminuted) in parallel or divergent fashion single screw for large fragments or non-union. bone grafting rarely needed complications pins are less stiff screw may need to be removed if crossing the physis Complications Stiffness incidence most common complication risk factors stiffness may be an early sign of a non-union or delayed union treatment usually self-resolving by 24 weeks 90% of motion returns and full motion is present by 48 weeks Delayed Union fracture that does not heal with 6 weeks of immobilization risk factors fracture that is seen more than 2 weeks after injury treatment may be treated with immobilization if minimally displaced surgical treatment if displaced must be followed until radiographic union as nonunion is common in this scenario Nonunion incidence higher rate of nonunion than other elbow fractures risk factors nonsurgical management mechanism - theoretical constant motion at fracture site from pull of the wrist extensors intra-articular (synovial fluid impede fracture healing) poor metaphyseal circulation to distal fragment prevent nonunion by preserving soft tissue attachments to lateral condyle stable internal fixation treatment goal is to obtain union of metaphyseal fragment, not restore joint surface may require bone graft ORIF with screw Cubitus Valgus ± tardy ulnar nerve palsy due to lateral physeal arrest or more commonly a nonunion slow, progressive ulnar nerve palsy caused by stretch incidence 10% less common than cubitus varus risk factors significant deformities that cause physeal arrest treatment supracondylar osteotomy after skeletal maturity and ulnar nerve transposition AVN incidence occurs 1-3 years after fracture risk factors posterior dissection can result in lateral condyle osteonecrosis (may also occur in the trochlea) Fishtail deformity area between medial ossification center and lateral condyle ossification center resorbs or fails to develop treatment supracondylar osteotomy Lateral overgrowth/prominence (spurring) incidence up to 50% regardless of treatment, families should be counseled in advance risk factors result of displacement of the metaphyseal fragment in addition to disruption of the periosteal envelope lateral periosteal realignment will prevent this from occurring spurring is correlated with greater initial fracture displacement Growth arrest incidence rare complication risk factors varus or valgus deformity treatment young patients may be treated with bar resection or osteotomy older patients best treated with completion of the epiphysiodesis and osteotomy Unsatisfactory appearance of surgical scar Prognosis Outcomes have historically been worse than supracondylar fractures articular nature, missed diagnosis, and higher risk of malunion/nonunion Associated posteromedial elbow dislocations prolonged return of ROM final ROM similar to isolated lateral condyle fracture