Summary A Monteggia fracture is defined as a proximal 1/3 ulna fracture with an associated radial head dislocation. Diagnosis is made with forearm and elbow radiographs to check for congruency of the radiocapitellar joint in the setting of an ulna fracture. Treatment can be isolated closed reduction in the pediatric population (if radiocapitellar joint remains stable). Adults and unstable injuries generally require ORIF of the ulna. Epidemiology Incidence rare in adults more common in children with peak incidence between 4 and 10 years of age different treatment protocol for children Etiology Associated injuries may be part of complex injury pattern including olecranon fracture-dislocation radial head fx coronoid fx LCL injury terrible triad of elbow Anatomy Ligament annular ligament Classification Bado Classification Type I 60% Fracture of the proximal or middle third of the ulna with anterior dislocation of the radial head (most common in children and young adults) Type II 15% Fracture of the proximal or middle third of the ulna with posterior dislocation of the radial head (70 to 80% of adult Monteggia fractures) Type III 20% Fracture of the ulnar metaphysis (distal to coronoid process) with lateral dislocation of the radial head Type IV 5% Fracture of the proximal or middle third of the ulna and radius with dislocation of the radial head in any direction Jupiter Classification of Type II Monteggia Fracture-Dislocations Type IIA Coronoid level Type IIB Metaphyseal-diaphyseal junction Type IIC Distal to coronoid Type IID Fracture extending to distal half of ulna Presentation Symptoms pain and swelling at elbow joint Physical exam inspection may or may not be obvious dislocation at radiocapitellar joint should evaluate skin integrity ROM & instability may be loss of ROM at elbow due to dislocation neurovascular exam PIN neuropathy radial deviation of hand with wrist extension weakness of thumb extension weakness of MCP extension most likely nerve injury Imaging Radiographs recommended view AP and Lateral of elbow, wrist, and forearm CT scan helpful in fractures involving coronoid, olecranon, and radial head Treatment Nonoperative closed reduction indications more common and successful in children must ensure stabilty and anatomic alignment of ulna fracture technique cast in supination for Bado I and III Operative ORIF of ulna shaft fracture indications acute fractures which are open or unstable (long oblique) comminuted fractures most Monteggia fractures in adults are treated surgically ORIF of ulna shaft fracture, open reduction of radial head indications failure to reduce radial head with ORIF of ulnar shaft only ensure ulnar reduction is correct complex injury pattern Monteggia "variants" with associated radial head fracture IM Nailing of ulna indications transverse or short oblique fracture Techniques ORIF of ulnar shaft fracture approach lateral decubitus position with arm over padded support midline posterior incision placed lateral to tip of olecranon develop interval between flexor carpi ulnaris and anconeus along ulnar border proximally, and interval between FCU and ECU distally techniques with proper alignment of ulna radial head usually reduces and open reduction of radial head is rarely needed failure to align ulna will lead to chronic dislocation of radial head ORIF of radial head approach posterolateral (Kocher) approach technique annular ligament often found interposed in radiocapitellar joint preventing anatomic reduction after ulnar ORIF treatment based on involved components (radial head, coronoid, LCL) Complications PIN neuropathy up to 10% in acute injuries treatment observation for 2-3 months spontaneously resolves in most cases if no improvement obtain nerve conduction studies Malunion with radial head dislocation usually caused by failure to obtain anatomic alignment of ulna treatment ulnar osteotomy and open reduction of the radial head Prognosis If diagnosis is delayed greater than 2-3 weeks complication rates increase significantly