https://orcid.org/0000-0001-6696-218X
Abstract
Paediatric Monteggia fracture is misdiagnosed in 28% of cases, with possible functional impairment in delayed diagnosis. Assessment of the radiocapitellar alignment on both anteroposterior and lateral views of the elbow is imperative, especially when an apparently isolated ulnar fracture is present. Although Bado I injuries are the most common and diagnosed on lateral radiographs, type III injuries often go unnoticed due to inadequate examination of the anteroposterior view. We present a case of a 6-year-old female patient with a neglected Monteggia fracture (Bado III). The patient underwent surgery 10 months after initial trauma, involving open reduction of the radial head, repair of the annular ligament, and proximal ulnar osteotomy. At 1 year follow-up, the patient achieved a QuickDASH of 0. This case highlights the importance of early recognition and appropriate imaging evaluation, while demonstrating that satisfactory outcomes can be achieved in chronic cases with proper surgical management.
Background
A Monteggia fracture is characterized by a fracture of the proximal ulna associated with a dislocated radial head. Despite their rarity, they pose an important diagnostic challenge [1, 2]. Several studies report that 28% of Monteggia fractures are initially missed, often because attention is focused on the ulnar fracture while the position of the radial head is overlooked [1]. The most commonly used indicator in clinical practice for evaluating radial head dislocation is the radiocapitellar line (RCL) [3]. Typically, the RCL—a line drawn through the centre of the radial neck and head—should intersect the capitellum on a lateral or anteroposterior (AP) radiograph, regardless of elbow flexion or extension. A deviation in the RCL suggests radial head dislocation [1]. Failure to identify the radial head dislocation at the time of injury may result in chronic Monteggia lesions, which are associated with progressive deformity, joint instability, and functional limitation [1, 2]. The management of a chronic Monteggia fracture is complex and often requires surgery to restore the anatomical alignment of the ulna and reduce the radial head [1, 4–6]. This article presents a rare case of chronic paediatric Monteggia fracture, Bado III, highlighting the diagnostic challenges and demonstrating the potential for favourable functional outcomes following adequate surgery.
Case presentation
A 6-year-old female patient presented at a secondary care hospital following trauma to her left elbow. At the initial radiographic assessment, an olecranon fracture was identified (Fig. 1).
Anteroposterior (A) and lateral (B) radiographs of the elbow at initial evaluation after trauma. An olecranon fracture is evident. When drawing the radiocapitellar line on the anteroposterior view, a lateral radial head dislocation becomes evident, initially overlooked.
Conservative treatment involving the application of a long-arm cast was initiated. Four weeks after the injury, at a follow-up appointment, radiographs showed an ulnar fracture malunion, as well as a lateral dislocation of the radial head, which had not been identified during the initial assessment (Fig. 2).
Elbow radiographs showing a proximal ulnar fracture malunion and radial head dislocation at 4 weeks after trauma (A). The radial head dislocation is not apparent on the lateral view (B).
This was consistent with a chronic Monteggia fracture, Bado type III. At this time, it was also noticed that the patient presented with digits and wrist extension deficit (PIN palsy), which had not been previously observed.
The patient was referred to a tertiary hospital, where she was observed 3 months after the initial injury. Complete spontaneous recovery of the neurapraxia was noted, as well as limited elbow extension-flexion (−30° to 110°) and limited forearm pronation-supination (10° to 30°). Due to persistent dislocation of the radial head and ongoing functional limitations, surgical treatment was planned. The surgery was performed 10 months after the initial injury.
An elbow lateral approach was performed to reduce the radiocapitellar joint, involving the excision of fibrosis and repositioning of the interposed annular ligament. The radiocapitellar joint was temporarily reduced and fixed with a K-wire. Then, an ulna opening wedge osteotomy was performed through a medial approach and fixed with a plate and screws. The annular ligament was repaired and the K-wire was removed. Radial head stability was observed during full pronation, supination, flexion, and extension. Fluoroscopy confirmed radiocapitellar and ulnar alignment (Fig. 3).
Lateral (A) and medial (B) surgical approaches. Intraoperative fluoroscopy showing radial head-capitellum provisional fixation with K-wire (C); ulnar opening wedge osteotomy, fixed with a plate and screws, and reduction of the radial head (D and E).
A long-arm splint immobilization was applied for a period of 6 weeks, after which a physiotherapy programme was initiated. Progressive improvement in elbow motion and function was observed at 2 and 4 months postoperatively. One year after surgery, the patient had achieved excellent clinical and functional outcomes (Fig. 4), with almost full recovery of elbow range of motion (with a residual flexion deficit of approximately 20°) and good radiographic alignment (Fig. 5). The patient achieved a Mayo Elbow Performance Score of 100 and a QuickDASH score of 0.
Patient functional outcome at 1 year postoperatively.
Radiographic follow-up at 2 months (A and B), 7 months (C and D) and 1 year (E and F): AP and lateral radiographs of the elbow showing proper radiocapitellar joint alignment.
Discussion/conclusion
Monteggia’s fractures in children remain an important diagnostic challenge. The injury may be easily overlooked, particularly when attention is directed mainly towards the ulnar fracture. Bado type III injuries often go unnoticed due to a lack of careful examination of the AP view. Thus, the alignment of the radial head with the capitellum should always be assessed in both AP and lateral views of the elbow. Failure to identify radial head dislocation may lead to chronic lesions requiring complex surgical management, as seen in this case [7].
Current clinical strategies for treating chronic Monteggia fractures in children focus on ulnar osteotomy and radial head reduction [5–9]. However, standardized treatment protocol or guideline remains elusive [7, 9].
Ulnar malunion is a significant obstacle to radial head reduction; therefore, ulnar osteotomy is a critical step in achieving radial head reduction and improving elbow joint function [6, 7].
K-wire fixation of the radiocapitellar joint has been advocated to promote further postoperative stability of the radial head reduction [10]. However, Dai et al. [11] reported that fixation of the radiocapitellar joint did not appear to prevent redislocation. Also, if the radial head is unstable after pin removal, ulna osteotomy revision should be considered [7, 11]. In our case, provisional radiocapitellar fixation with a K-wire was performed. This fixation was then removed after ulnar osteotomy, after which radial head stability was assessed and confirmed through pronosupination.
The decision between annular ligament repair and reconstruction in paediatric chronic Monteggia fractures remains a subject of debate. Some studies show that correcting the biomechanical alignment solely through ulnar osteotomy is insufficient to maintain the stability of radial head reduction, suggesting that annular ligament reconstruction can minimize postoperative redislocation [8, 9]. Conversely, others suggest that the annular ligament remains intact in patients with Bado I and Bado III chronic Monteggia fractures. Thus, reduction without reconstruction is feasible. This was demonstrated in the present case, in which only partial repair and retensioning were performed [4, 5, 7].
The timing of surgical treatment is another important factor influencing outcomes [7]. However, satisfactory outcomes can still be achieved in delayed cases when anatomical alignment is properly restored, as seen in this case [5, 7].
Considering that Monteggia fractures in children are frequently underdiagnosed injuries. This case highlights the importance of maintaining a high index of suspicion in paediatric elbow trauma and performing careful radiographic evaluation to prevent chronic lesions and consequent functional impairment. Although early diagnosis remains crucial, surgical management can restore the anatomical alignment of the ulna and radial head in chronic paediatric Monteggia fractures, allowing for excellent functional recovery even several months after the initial injury.
Conflicts of interest
None declared.
Funding
None declared.
