summary Medial Epicondylar Fractures are the third most common elbow fracture seen in children and are usually seen in boys between the ages of 9 and 14. Diagnosis is made with plain radiographs. Treatment is nonoperative for the majority of fractures. Operative management is indicated for entrapment of medial epicondyle fragment in the joint, extension to the articular surface with medial condyle involvement (articular surface), and open fractures. Epidemiology Incidence account for up to 20% of all pediatric and adolescent elbow fractures Demographics 75% occur in boys between the ages of 9 and 14 years increasing in frequency due to the increased athletic demands in the pediatric population. Etiology Pathoanatomy avulsion mechanism fracture occurs secondary to excess valgus stress with contraction of flexor-pronator mass direct trauma Associated injuries elbow dislocation associated with elbow dislocations in approximately 50-60% of cases most spontaneously reduce but fragment remains incarcerated in joint in ~ 15% of cases Anatomy Osteology medial epicondyle last ossification center to fuse in distal humerus does not contribute to longitudinal growth (apophysis) origin of flexor-pronator mass and UCL 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 Muscles/ligaments common flexor-pronator wad muscles of medial epicondyle include pronator teres flexor carpi radialis palmaris longus flexor digitorum superficialis flexor carpi ulnaris Blood supply anterior branches of inferior ulnar collateral artery posterior branches of the superior and inferior ulnar collateral artery Classification No routinely used classification system Can be more simply classified as acute vs. chronic acute subtypes Nondisplaced Minimally displaced Displaced Fragment entrapped in joint Fracture through epicondyle apophysis chronic related to tension stress injuries Presentation Symptoms medial elbow pain Physical exam valgus instability ecchymosis (especially with direct trauma) ulnar nerve dysfunction- motor and sensory function should be documented in all cases generalize swelling suggests elbow may have dislocated Imaging Radiographs displacement is difficult to measure accurately as medial epicondyle is located on the posteromedial aspect of the distal humerus and fragment displaces anteriorly recommended views AP and lateral of elbow internal oblique view to evaluate displacement distal humeral axial view may also improve accuracy of measuring displacement obtained by angling beam 25 degrees anterior to long axis of humerus CT most accurate but associated with increased radiation Differential Medial condyle fracture Simple elbow dislocation Treatment Nonoperative immobilization (1-3 weeks) in a long arm cast with elbow flexed to 90 degrees indications controversial < 5mm displacement amount of true displacement difficult to determine on plain radiographs outcomes lower rate of osseous union rate compared to surgically treated patients radiographic nonunion (or fibrous union) often asymptomatic Operative open reduction internal fixation indications absolute displaced fx with entrapment of medial epicondyle fragment in joint extension to the articular surface with medial condyle involvement (articular surface) open fracture relative ulnar nerve dysfunction > 2-15mm displacement, also controversial >2-5 mm in valgus stress athletes such as throwers or gymnasts associated elbow dislocation Techniques Open Reduction Internal Fixation approach medial approach to elbow typically with patient supine and arm abducted to 90 degrees, a prone position also described incision is made directly over medial epicondyle brachialis/triceps interval ulnar nerve at risk technique identify and protect ulnar nerve (easiest from proximal to distal) reduce fracture screw fixation (often cannulated) a washer may improve fixation, but more prominant avoid iatrogenic comminution during screw insertion K-wires indicated for smaller fragments or in younger children Complications Non-union majority are asymptomatic odds of radiographic union are 9 times greater with surgery Nerve injury ulnar nerve (reported between 10% - 16%) neuropraxia after dislocation will usually resolve with observation radial nerve at risk with bicortical screw fixation Missed incarceration in elbow joint consider in younger patients without ossification of medial epicondyle Elbow stiffness the most common complication is the loss of few degrees of elbow extension associated with prolonged immobilization, occurs after nonoperative and operative treatment Prognosis Good to excellent results have been reported for both surgical and non-surgical management