Paediatric bilateral ‘floating elbow’

Abstract

A child sustained an ipsilateral supracondylar humerus (SCH) and distal both-bone forearm fractures bilaterally, in addition to facial injuries, following a fall from height. He was managed surgically by closed reduction and pinning for both SCH and distal end radius fractures bilaterally. At the final follow-up, all the fractures had united uneventfully, and he had no functional limitations or cosmetic concerns. We conclude that a floating elbow in the paediatric population is an uncommon injury, and the bilateral scenario is even rarer. One should be vigilant for compartment syndrome; early surgical fixation may give better results.

BACKGROUND

Following distal both-bone forearm (BBFA) injuries, fractures around the elbow are the second most common orthopaedic injuries in paediatrics, accounting for nearly 10% of all orthopaedic injuries in this age group. The presence of fractures involving the same side humerus and both bones of the forearm is classically described as a ‘floating elbow’. Both these injuries are relatively rare, with the incidence ranging from 3–13%.¹ The ipsilateral supracondylar humerus (SCH) and BBFA fractures are high-impact injuries usually resulting from falls from a height.²

These injuries have been presumed to be perilous for decades, with a high risk of complications, including compartment syndrome and neurovascular injuries.³ Therefore, in the past, different authors have advocated various methods of addressing these injuries, which cover a spectrum of options ranging from conservative management for both fractures, operative management for SCH only, and operative management for both.^{1 4–6} Ambiguity continues to exist over appropriately managing these injuries, mainly focusing on the need for surgical fixation, the order of fixation, and complication rates.

Our case report reviews the presentation, evaluation, management, and rehabilitation of a bilateral floating elbow in a paediatric patient who presented to our level I trauma centre. This case is unique because bilateral floating elbow injuries are rare in the paediatric age group, with no estimated incidence of these injuries in the current English literature.

Proper consent and permission for sharing the clinical data and images were obtained from the child’s parents.

CASE PRESENTATION

A middle childhood-aged, right-hand dominant boy fell from a height of approximately 10 feet (3 m) while playing at home and landed on both his outstretched hands. He was initially taken to a nearby private hospital, from where the patient was referred to our level I trauma centre 1.5 hours after the injury. On initial presentation, the Glasgow Coma Scale of the child was E4 M6 V5 and he was haemodynamically stable, with left periorbital ecchymoses. In the secondary survey, we found substantial swelling and deformity of the elbow and the distal forearm bilaterally (figure 1). A puncture wound and bruise were noticed on the left antecubital area. There was no distal neurological deficit or signs of compartment syndrome bilaterally. Radiographs of the bilateral upper limbs revealed an open SCH fracture (Gartland type III) on the left elbow (figure 2), an ipsilateral comminuted fracture of the distal radius physis (Peterson type I), and an undisplaced distal ulna fracture (figure 3). This injury is classically described as a ‘floating elbow’, which could be categorised as type VI in the Cuellar-Nieto classification of floating elbow injuries.

Figure 1.

Clinical picture of the wound and preoperative radiographs of the left side showing a Gartland type III supracondylar humerus fracture and a Peterson type I distal radius physeal injury with a distal ulna fracture.

Figure 2.

Preoperative radiographs of the right side showing a Gartland type II supracondylar humerus fracture and a distal radius metaphyseal fracture with a distal ulna fracture.

Figure 3.

Postoperative radiographs of bilateral elbow and forearm.

Similarly, on the right side, there was a Gartland type II SCH fracture along with an ipsilateral distal radius metaphyseal (Arbeitsgemeinschaft für Osteosynthesefragen/Orthopedic Trauma Association (AO/OTA) 23 M/3.1) injury with an undisplaced distal ulna fracture; this injury was classified as type I as per the Cuellar Nieto classification. The child’s upper limbs were splinted with above elbow plaster of Paris (POP) back slab in 40–50^o elbow flexion, and elevated. The child was continuously monitored for the development of compartment syndrome by assessing the three As, that is, anxiety, increased analgesia requirement, and agitation. A head CT was obtained, which was grossly normal.

TREATMENT

The patient was taken to the operating room within 4 hours of the presentation. The surgery was performed under general anaesthesia by a single team, first on the left side, followed by the right side. Left-side punctured wound debridement and wound lavage were done, followed by closed reduction of the SCH and pinning with three lateral divergent K wires. On either of the sides, fixation of the humerus was performed first, and the decision to fix the radius was taken later because of the doubtful stability of closed reduction alone and apprehension of applying POP circumferential casting in a floating elbow with a concern for compartment syndrome. Left side distal radius injury was also reduced and pinned. Care was taken to make a single attempt while pinning the distal radius injury. Likewise, the right side SCH was pinned using two lateral divergent K wires following closed reduction, and the distal radius was also pinned later. Post fixation, the child was given bilateral above-elbow POP slabs in approximately 50–60° of flexion, and the limb elevation was done. Throughout the postoperative course in the hospital, the distal neurovascular status remained intact and was monitored regularly for compartment syndrome. The patient was discharged after 72 hours following surgery, and analgesics (syrup ibuprofen 10 mg/kg) were prescribed for breakthrough pain, if any. The pin tracts remained healthy, and the initial open puncture wound healed uneventfully.

OUTCOME AND FOLLOW-UP

The first follow-up was 1 week following surgery to look for any fracture displacement. At this point, no displacement of fractures was noticed, and the alignment and reduction remained the same as in postoperative images immediately following surgery. At 3 weeks, the slabs were discontinued, and K-wires were removed after an X-ray showed satisfactory bony bridging in orthogonal views. The functional range of motion exercises of the elbow and wrist joints were started. At 6 weeks of follow-up, functional outcome was assessed using the Mayo Elbow Performance Scale (MEPS),⁷ estimated at 70. At the subsequent follow-up at 3 months, the score had improved to 80. Eventually, the child regained his complete functional activity at a 6-month follow-up with a MEPS score of 100. The range of motion was symmetrical bilaterally at the final follow-up, with 0–120° of flexion, 70° of pronation, 80° of supination, and 90° of wrist flexion and extension. The carrying angle was also 10° bilaterally (figures 4 and 5). Finally, a telephone follow-up was done after 1 year. The parents are very pleased with the results. The child is performing well and participating actively in outdoor games with his peers. There are no functional or cosmetic concerns.

Figure 4.

Six-month follow-up radiographs of the bilateral arm and forearm.

Figure 5.

Clinical images showing limb alignment and range of motion at elbow and wrist at final follow-up.

DISCUSSION

In 1980, Stanitski et al, for the first time in the English literature, described an injury pattern involving simultaneously an SCH fracture and one or both bone forearm (BBFA) fracture which they classically termed ‘floating elbow’ in their case report.³ These injuries are peculiar as they are associated with high-impact trauma, the most common mechanism being a fall from a height (eg, a fall from a monkey bar) followed by a roadside accident.⁸ Novel mechanisms like accidental rotating injuries to the upper limb after grinding in washing machines or spin dryers are also reported in the literature. The crux is that these injuries are severe and are high-impact injuries with significant involvement of soft tissues.⁹

The notion about the dangerous nature of this injury in children possibly arises from the reports of complications that occur with adult floating elbow injuries. Hwang et al reported that the risk of compartment syndrome was 50 times greater in floating elbow injuries as compared with isolated distal radius injuries.¹⁰ Blakemore et al, in their case series, reported the incidence of acute compartment syndrome in paediatric floating elbow cases at around 33%.¹¹ However, a recent systematic review by Ditsios et al found the rate of compartment syndrome in adults to be only 1.2%.¹² This was similar to the results of the systematic review by Baghdadi et al, who reported the rate of compartment syndrome to be only 2% in paediatric patients with floating elbows.⁸ These reviews suggest that the rate of complications associated with this injury has been overestimated. However, the risk of compartment syndrome continues to exist, especially with displaced fractures receiving delayed treatment, leading to potentially devastating complications. Hence, these fractures should be reduced and stabilised as urgently as possible.

The reported incidence of floating elbow in the current literature varies from as low as 3% to as high as 17% of all SCH fractures.³ The incidence of floating elbow injury patterns involving the bilateral upper limbs in a child is not known to the best of our knowledge.

SCH fractures are classified using the Gartland classification system, but the presence of floating elbow injuries requires a more complex approach to classify. One such classification system has been proposed by Cuéllar and Nieto from Mexico, which classifies floating elbow injuries in children aged 4 to 14 years into six types based on fracture morphology, neurovascular compromise, presence of a wound, and time since injury.¹³ However, this classification system focuses only on the prognosis of the injury based on the initial injury characteristics and does not govern the treatment of the fractures.

Management of these injuries is always controversial, and there has yet to be a common consensus to date. Reed et al, in their case series, managed this pattern of injuries by conservative methods and found no increased incidence of compartment syndrome in their cases.⁴ Ring et al also managed 10 patients conservatively in their series of paediatric floating elbows. Of these 10 patients, two developed compartment syndrome, and four had an impending compartment syndrome for which the cast had to be split.¹⁴ Biyani et al treated SCH fractures with closed reduction percutaneous pinning (CRPP) and forearm fractures in closed reduction followed by casting.¹⁵ They managed the SCH fractures first, followed by forearm fractures. They reported excellent to good outcomes in many of their cases. The treatment of SCH fractures, that is, CRPP, was almost consistent in recent studies, but managing forearm fractures was still debatable. Some authors preferred managing forearm fractures with closed reduction and casting, whereas others advocated percutaneous pinning after closed reduction. Roposch et al conducted a retrospective study to determine the outcomes of pin fixation in both bone fractures versus casting alone.¹⁶ They reported no complications in the pin fixation group.

In contrast, the risk of displacement of reduction in casting was found in three out of 18 cases; therefore, managing displaced fractures of the forearm with CRPP was advocated. In their retrospective review, Ring et al reported similar outcomes, where they found no increased risk of complications in the group managed operatively with percutaneous pinning.¹⁴ They stated that the ability to maintain the reduction after pin fixation in a non-circumferential cast compared with the circumferential cast requirement in the closed reduction group was predisposed to increased complication rates.

There is also no common consensus and justification for a sequence of management of these injuries. The traditional approach is to fix the SCH fracture first and then manage the forearm fracture. Templeton and Graham advocated the management of the SCH fracture first because they believed that maintenance of reduction and limb access for monitoring compartment, neurological status, dressings, and the closure of open injuries may be cumbersome if the BBFA fracture is managed first.¹⁷ Only some authors have addressed the forearm fractures first. In a series of 23 cases by Tabak et al, the authors found it more straightforward to reduce and fix the forearm fractures first. They experienced no difficulty managing the SCH fractures and monitoring the distal forearm for neurovascular status.⁶

In our case, the first SCH fractures were managed with CRPP per standard techniques, as fixing the SCH fractures has always been the standard of care. The question arises whether to fix the distal injury or not. We took this decision intraoperatively following closed reduction and fixed radius as we found the injury was unstable, and we wanted to avoid applying a circumferential cast postoperatively. However, it is acknowledged that the distal forearm fractures of both bones can be managed by closed reduction alone as the remodelling potential is very high distally. At our centre, we usually apply only a POP back slab, not a circumferential cast, following the pinning of an SCH fracture. In our experience, there was no loss of reduction following CRPP and back slab application.

CONCLUSION

A floating elbow in the paediatric population is an uncommon injury, and the presence of this injury bilaterally is even rarer. To the best of our knowledge, no literature that quotes the occurrence of a bilateral floating elbow injury is available. The management of such injuries is controversial, and there is no consensus on fixing the distal fracture. We successfully managed a paediatric bilateral floating elbow case operatively and achieved satisfactory union and functional elbow and wrist range of motion at the final follow-up. Therefore, we recommend that the SCH fractures be reduced and pinned, and the management of the distal injuries should be individualised and tailored depending on the intraoperative findings.

Learning objectives.

• Bilateral floating elbow in paediatric orthopaedic trauma is a rare presentation and should be managed with extreme caution.

• Management of these injuries is controversial; no consensus exists.

• We recommend surgical management of these injuries, though one should individualise the need depending on the intraoperative stability of distal forearm injuries.

Ethics statements

Patient consent for publication

Consent obtained from parent(s)/guardian(s).