Summary Medial condyle fractures are a rare traumatic injury most commonly occurring in children 2-9 years of age caused by a fall onto an elbow. Diagnosis is typically made with plain films, although these injuries can be difficult to detect, especially in young children. MRI may be of utility in assisting with prompt diagnosis. Treatment is usually operative with open reduction and fixation with either Kirschner wires or screws. Epidemiology Incidence incidence rare fracture in children 1-2% of all pediatric elbow fractures Demographics age bracket mean age 4.6 years (typical range 2-9 years) male:female = 2:1 Etiology Pathophysiology mechanism of injury 2 theories varus force on an extended elbow or fall directly onto the flexed elbow, with force transmission via the olecranon or coronoid process into the medial condyle valgus force on an extended elbow leading to condyle avulsion resulting from overpull of the forearm flexors pathoanatomy fracture line extends from distal humeral metaphysis to articular surface depending on degree of fracture extension, may present radiographically as a Salter-Harris II or Salter-Harris IV fracture elbow tends to subluxate posteromedially because of the loss of trochlear stability Anatomy Ossification centers of the elbow medial (internal) epicondyle ossifies/appears at age 5 years fuses at age 16-18 years trochlea ossifies/appears at age 7 years fuses at age 12-14 years age of ossification and age of fusion are two independent events that must be differentiated Ossification Centers of the Elbow Years at Ossification Years at Fusion Illustration Capitellum 1 12-14 Radial Head 3 14-16 Medial Epicondyle 5 16-18 Trochlea 7 12-14 Olecranon 9 15-17 Lateral Epicondyle 11 12-14 Range of Motion in extended elbow 40% of weight is through ulnohumeral joint 60% of weight is through radiohumeral joint this may explain why lateral condyle fractures are more common than medial condyle fractures Ligaments medial (ulnar) collateral ligament (MCL) overview MCL is composed of the anterior, posterior and transverse bundles provides resistance to valgus and distractive stresses anatomy originates at anteroinferior aspect of medial epicondyle inserts on sublime tubercle of medial coronoid process components anterior bundle of MCL most important restraint against valgus stresses radial head is 2nd most important posterior bundle of MCL forms the floor of the cubital tunnel primary restraint to valgus stress in maximal elbow flexion if this is contracted, flexion may be limited transverse bundle of MCL Tendons tendon name origin insertion function Muscles common flexor-pronator mass originates from medial epicondyle pronator teres flexor carpi ulnaris palmaris longus flexor carpi radialis Blood Supply brachial artery lies anteriorly in antecubital fossa, runs underneath lacertus fibrosus most of the blood supply of the distal humerus comes from the anastomotic vessels that course posteriorly Nervous System ulnar nerve origin medial cord of brachial plexus anatomy at elbow runs medial to brachial artery, pierces medial intermuscular septum (at the level of the arcade of Struthers) and enters posterior compartment traverses posterior to the medial epicondyle through the cubital tunnel innervation at elbow gives off branches to the elbow joint no innervation in the upper arm first motor branch to FCU is found distal to the elbow joint Classification Common Kilfoyle Classification Type I nondisplaced fracture through the metaphysis only Type II complete fracture through the epiphysis, no rotational displacement Type III severe displacement with rotation of the fragment, articular surface may be incarcerated in elbow joint Presentation History fall onto outstretched hand fall onto flexed elbow Symptoms common symptoms location medial elbow pain and swelling severity may be subtle if fracture is minimally displaced aggravating / alleviating factors rare symptoms Physical exam inspection deformity swelling palpation range motion flexion extension rotation instability vascular neuro provocative tests Imaging Radiographs recommended views AP Lateral Oblique findings normal anatomy important to differentiate this from a medial epicondylar fracture this may be challenging in the very young child presence of metaphyseal ossification within the epiphysis suggests involvement of the articular surface measurements basic measurements (tibial clear space) advanced measurements (pelvic incidence) criteria dictating treatment basic criteria advanced criteria sensitivity & specificity CT indications advanced views a findings basic findings advanced findings sensitivity and specificity MRI indications a views a findings basic findings advanced findings sensitivity and specificity Ultrasound indications preferred views finding basic findings advanced findings sensitivity/specific Bone scan indications when do you order sensitivity and specificity Studies Labs serum urine surface (nasal swab, sputum) Invasive studies Histology gross anatomy histology low power high power immunostaining Electrophysiologic studies basic findings advanced findings Differential Differential A key findings that differentiate topic from differential A found with topic key finding A found with differential A key finding A Differential B key findings that differentiate topic from differential B found with topic key finding A found with differential key finding A key finding C Diagnosis Made Treatment Nonoperative long arm cast immobilization x 4-6 weeks + close radiographic monitoring indications Type I fractures nondisplaced Type II technique cast with elbow in approximately 90 degrees as long as swelling is mild weekly follow up and radiographs every week x first 3 weeks, including oblique view occasionally > 6 weeks of casting is needed Operative open reduction + percutaneous pinning indications skeletally immature displaced Type II fractures Type III fractures techniques variation of treatment A (just list the option to chose from) indication b outcomes open reduction + screw fixation indications skeletally mature same Kilfoyle types as for pin fixation techniques variation of treatment A (just list the option to chose from) outcomes Techniques Nonoperative (Immobilization) indications technique pros/cons complications CRPP indications approach technique complications (ONLY if specific to this treatment) ORIF indications approach technique complications Resection / Nerve Decompression / Ectomy indications approach technique complications Repair indications approaches techniques complications Reconstruction indications approach technique complications Arthrodesis indication approach techniques complications Arthroplasty indications approach techniques complications Complications Avascular necrosis of the trochlea blood supply to the trochlea is terminal with no collateral flowblood supply enters posteriorly and can be disrupted by destruction of soft tissues during fracture or surgical attempts to reduce the fracture blood supply enters posteriorly; can be disrupted by destruction of soft tissues during fracture or intraoperative reduction attempts Nerve Injury ulnar nerve injury incidence risk factors diagnosis treatment tested treatment in bold blue indications indication A Malunion / Nonunion / Loss of Reduction incidence risk factors same risk factors as AVN of the trochlea diagnosis treatment risk of avascular necrosis is high in operative treatment of nonunion because takedown of forearm flexors is required to expose fracture site better functional results from accepting a nonunion than acquiring avascular necrosis in patients who present late, supracondylar osteotomy to improve motion and reduce deformity is an alternative to taking down the nonunion site Physeal Injury incidence risk factors medial condyle fractures are a type of Salter Harris IV diagnosis treatment Recurrent Instability Failure of Treatment Effect / Persistent Pain incidence risk factors diagnosis treatment Stiffness / Loss of Motion / Arthrofibrosis / Heterotopic Ossification incidence risk factors diagnosis treatment Prognosis Natural history of disease / Prognosis without treatment Prognostic variable favorable negative Survival with treatment