n Case Report Ulnar Fracture With Late Radial Head Dislocation: Delayed Monteggia Fracture ANDREA STITGEN, BS; JAMES J. MCCARTHY, MD; BLAISE A. NEMETH, MD; KATHRYN GARRELS, MD; KENNETH J. NOONAN, MD abstract Full article available online at ORTHOSuperSite.com. Search: 20120222-35 Monteggia fractures are rare but commonly discussed lesions, with increasing compli- cations due to late diagnosis. This article describes a case of a Monteggia fracture with delayed dislocation of the radial head. Previous radiographs of a 2-year 8-month-old boy show complete fracture of the distal ulna, with no radial head dislocation. The radial head remained well positioned after 4 weeks. Seven years later, he sustained another arm injury. He was diagnosed with a hematoma but was later believed to have nursemaid’s elbow. He presented to our institution 5 weeks after the injury, and the radial head was found to be chronically dislocated, indicating a displacement occur- ring sometime during the past 7 years. After failing conservative treatment, the patient underwent surgical repair. The annular ligament was reconstructed using a harvested A triceps fascia band, and an ulnar osteotomy was performed. A review of the literature found few reports of delayed Monteggia fractures, which accounted the delayed dislocations to ulnar angulation. However, our patient showed minimal ulnar angular deformity. We propose that the initial fracture disrupted the an- nular ligament and the radial head spontaneously relocated prior to being seen, which put the radial head at risk for later dislocation. We present an alternative hypothesis B of dislocation after fracture healing and report the longest known period of delay be- Figure: Anteroposterior (A) and lateral (B) forearm tween fracture and dislocation. radiographs of a 9-year-old patient showing the radial head anteriorly displaced to the capitellum and abnormal location of the radial head (red line). Slight remodeling of the anterior distal humerus is present. Ms Stitgen and Drs McCarthy, Nemeth, Garrels, and Noonan are from the Department of Orthopaedics, University of Wisconsin, Madison, Wisconsin. Ms Stitgen and Drs McCarthy, Nemeth, Garrels, and Noonan have no relevant financial relation- ships to disclose. Correspondence should be addressed to: Kenneth J. Noonan, MD, Department of Orthopaedics, University of Wisconsin Medical Foundation Centennial Building, 1685 Highland Ave, #6170-11D, Madison, WI 53705 ([email protected]). doi: 10.3928/01477447-20120222-35 e434 ORTHOPEDICS | ORTHOSuperSite.com DELAYED MONTEGGIA FRACTURE | STITGEN ET AL Monteggia fracture is an injury in wrist. He was placed which the radial head is dislocat- in a long-arm cast at Aed in conjunction with a fracture 90° of flexion. or angulation of the ulna.1 This lesion is Four weeks later, rare, accounting for 0.7% of elbow frac- the cast was re- tures and dislocations.2 Although fore- moved. The fracture arm fractures are more easily recognized, appeared to be well radial head dislocations are frequently healed. Radiographs missed,1-11 which may be attributable to showed good cal- difficulty in interpreting radiographs. Up lus formation and to 50% misdiagnosis or late diagnosis rate reasonable position was found in 1 study.3 Furthermore, re- of the distal ulna construction for late diagnosis has count- (Figure 2). The radial less complications, including nerve palsy, head was well posi- compartment syndrome, loss of range tioned in relationship of motion (ROM), nonunion, malunion, to the capitellum. and osteoarthrosis.1-9 Thus, unrecognized No further follow-up Monteggia fractures are a repeated cause was performed. of malpractice suits.9 In some cases, the At age 9, the 1 2A 2B treating physician failed to obtain a radio- patient rolled off graph of the elbow. Therefore, in cases of a mattress and Figure 1: Initial lateral fore- Figure 2: Lateral (A) and oblique (B) forearm ra- arm radiograph showing a diographs 4 weeks after injury showing the frac- late diagnosis, it is assumed that the radial was taken to the distal ulnar fracture, with no ture healing, with minimal angular deformity of head was dislocated but not detected. This emergency room. evidence of anterior disloca- the distal ulna and the proximal radius reduced in article presents an alternative hypothesis: Radiographs ini- tion of the radial head. regard to the capitellum. in some instances, the radial head may tially revealed a dislocate after the ulna has healed. hematoma. A second opinion postulated head could be reduced but was unstable. nursemaid’s elbow. He was placed in a Therefore, an annular ligament recon- CASE REPORT cast, and radiographs showed radial head struction was performed with a harvested A 2-year 8-month-old boy fell while displacement after 2 weeks. An attempted triceps fascia band, followed by an ulnar jumping on his parents’ bed and report- closed reduction was performed under an- osteotomy, and was fixed with a 6-hole ed arm pain. Unaware of the severity of esthesia, and he was placed in a long-arm plate. The patient was placed in a long- the fall, the parents waited until the next cast. arm cast at 60° flexion and full supination. morning for medical attention, when the The patient presented 5 weeks after in- Anteroposterior and lateral radiographs boy was still not using his arm normally. jury. He reported no pain or discomfort, showed the radial head to be reasonably Both upper extremities had normal and neurovascular status was normal. aligned with the capitellum. neurovascular status and full shoulder, Anteroposterior and lateral radiographs Five months postoperatively, radio- elbow, and wrist ROM. However, supina- confirmed radial head dislocation anterior graphs showed radial head alignment to tion and pronation were painful, and point to the capitellum (Figure 3). Remodeling be retained and a healed osteotomy site tenderness was apparent in the distal one- the anterior aspect of the distal humerus (Figure 4). The patient reported no pain, third of the arm. Mild discomfort existed where the dislocated and dysplastic ra- had full flexion-extension ROM and full with palpation at the radial head. dial head had been articulating indicated supination, and could pronate 10°. He is Radiographs revealed a complete frac- a possible chronic dislocation of unknown continuing physical therapy to improve ture in the distal one-third of the ulna, with duration. The patient’s parents opted not forearm pronation. a well positioned radial head (Figure 1). A to further treat the dislocation. sugar-tong splint was placed. At follow-up After 2 months, the pain became sig- DISCUSSION the following week, repeat radiographs of nificant, and the patient had limited mo- Monteggia fractures were first de- the proximal and distal radial ulnar joints bility; therefore, surgery was performed. scribed in 1814 by Giovanni Monteggia.3 showed a well-reduced radial head. The pa- The radial head could not be reduced in- These were later categorized by Bado12 tient was able to flex and extend his elbow traoperatively due to interposed scar and into 4 groups depending on the direc- freely and minimally flex and extend his capsule. After this was removed, the radial tion of dislocation and force of impact. MARCH 2012 | Volume 35 • Number 3 e435 n Case Report Physicians have long struggled with this trauma. Watson-Jones4 reported “No frac- ture presents so many problems; no injury is beset with greater difficulty; no treat- ment is characterized by more general failure.” Monteggia fractures must be docu- mented early for the best outcomes.1,3,5-8 Late diagnosis results in an unpredictable and more complex treatment. A delay in diagnosis greatly increases the risk of 3A 3B complications, causing more pain, insta- bility, and deformity, making accurate and Figure 3: Anteroposterior (A) and lateral (B) forearm radiographs of a 9-year-old patient showing the radial head anteriorly displaced to the capitellum and abnormal location of the radial head (red line). Slight timely diagnosis of Monteggia fractures remodeling of the anterior distal humerus is present. essential. Perhaps because of the increase in complications seen with delayed diagno- sis, missed fractures and dislocations are the most common source of malpractice claims in emergency medicine.9 Acute Monteggia fractures are often misdiag- nosed because of insufficient radiographs that exclude the elbow joint or misinter- pretation of radiographs, especially when multiple ossification centers are present. Swelling of the soft tissue surrounding 4A 4B 3-6 the joint can also mask the dislocation. Figure 4: Lateral (A) and anteroposterior (B) radiographs 5 months after ulnar osteotomy and annular Thus, when a patient presents with a ligament reconstruction showing the radial head and good healing of the ulna. chronic radial head dislocation and a his- tory of an ulnar fracture, it is assumed tent deformation of the ulna. The longest which occurred after the patient’s ulna that the patient had an unrecognized acute previously reported delay between initial fracture in our case, sometime within the Monteggia fracture dislocation. The cur- injury and recognition of dislocation was following 7 years. However, because no rent case offers another possible explana- 18 months.6 In this case, an ulnar fracture discomfort or tenderness was reported tion: the radial head was not yet dislocated was present, with no initial radial head by the patient, we are unable to identify and became dislocated after the fracture dislocation and throughout 7 weeks of when the dislocation occurred. It is pos- had healed. Other reports indicated that casting. The next radiographs were taken sible that the radial head was susceptible ulnar angulation may cause a delayed at 18 months when the patient reported for dislocation from the minimal trauma dislocation. However, this was not likely decreased ROM, and they revealed a dis- that occurred when this 9-year-old boy in our case because radiographs revealed located radial head.6 rolled off the mattress.