Pulled elbow: A case of an atypical presentation in an infant

Sahar Mohammed Al Blooshi11, Dr Ali Nawaz2, Mr Haroon Majeed*3

1Resident Emergency Medicine, Tawam Hospital, Al Ain, Abu Dhabi, United Arab Emirates.

2Consultant Emergency Medicine, Tawam Hospital, Al Ain, Abu Dhabi, United Arab Emirates.

3Consultant Trauma and Orthopaedic Surgeon, Manchester University NHS Foundation Trust, Oxford Road, Manchester, England, United Kingdom.

*Corresponding Author: Haroon Majeed, MBBS; MRCS; MSc; FEBOT; FRCS (Tr & Orth), Consultant Trauma and Orthopaedic Surgeon, Manchester University NHS Foundation Trust, Oxford Road, Manchester, England, United Kingdom.  Email ID: haroon.majeed@nhs.net

Received: March 27, 2019; Accepted: March 28, 2019; Published: May 05, 2019

Abstract

The pulled elbow is more common between the ages of 1 and 4 years. A few cases have been reported in the literature under the age of 1 year. The usual mechanism of injury is forced pronation of an extended arm. We present a case of pulled elbow in an 8 months old infant with an atypical mechanism. The child rolled over to her side and stopped moving her left elbow. After excluding fracture with plain radiographs, pulled elbow was suspected on clinical assessment. Supination-flexion reduction method was used under analgesia. The child was observed until started mobilising the arm fully. A high index of suspicion for pulled elbow should be kept in infants despite the absence of the usual presentation. Careful clinical assessment and prompt reduction method result in regaining the normal function.

Introduction

Nursemaid’s elbow, commonly known as pulled elbow, is defined as subluxation of the radial head caused by axial traction or a sudden pull of an extended and pronated forearm [1]. Radial head subluxation accounts for two-thirds of the upper extremity injuries in pre-school children and is the most common cause of sudden inability to mobilise the elbow [2]. The radial head slips out of the annular ligament in to the supinator muscle [3]. Pulled elbow has been reported to be more common in children between the ages of 1 and 4 years with a peak incidence between 2 and 3 years [3, 4]. Some epidemiological studies have reported a slightly higher incidence in girls, however a recent large study reported no significant gender difference in its incidence [3]. Fewer cases have been reported under the age of 1 year [4, 5]. Typical history of a pulled elbow includes forced pulling the child along by the hand or the child tossing and turning with his or her arm under the body [3, 4]. The presentation usually includes sudden acute pain with the child seen not to mobilise the affected arm and holding it close to his or her body. Plain radiographs are recommended to exclude fractures [2]. Treatment typically includes flexion-supination manoeuvre however, hyperpronation method is also used, with some studies reporting this to be less painful [6, 7]. Successful reduction leads to return of full function and favourable prognosis [4]. A large series of 2331 cases of pulled elbow during a 10-years study period, reported that 3.9% of pulled elbows occurred in children under the age of 1 year [4]. We report a case of pulled elbow in an eight-month old child with atypical history and presentation.

Case History

Her mother brought an eight-month old girl to the emergency department as she noticed the child had stopped moving her left arm. There was no reported history of trauma, fall or forced-pulling the child with hands. However, her mother noticed that the child rolled over to her side while crawling, followed by crying and inability to move her left arm. There was no delay in presentation and the child was brought within an hour of this occurrence. There were no other reported health problems or similar history in the past. The suspicion of non-accidental injury was sufficiently excluded on history. On examination the child was sitting comfortably in her mother’s lap. Her left arm was noticed to be held in extension and pronation with no visible bruising or deformity. On closer look there was a subtle swelling around the left elbow compared to the opposite side. The child was hesitant for her affected elbow to be palpated or attempted to be mobilised. Plain radiographs of the elbow and the rest of the arm were obtained and the possibility of a fracture was excluded (Figure 1). Despite the very young age of the child (< 1 year) and the lack of usual history of presentation, the diagnosis of a pulled elbow was suspected. After administration of sufficient analgesia and explanation to the child’s mother, an attempt of supination and flexion manoeuvre was performed holding the child’s elbow at 90° with one hand while supinating the wrist and flexing the elbow with the other. Although there was no audible click during this manoeuvre but the child was noticed to be more comfortable and started mobilising her elbow actively within 10 to 15 minutes. She was observed for a period of 30 minutes and subsequently discharged from the emergency department with appropriate advice to her mother with regards to analgesia and mobilisation. A telephonic follow-up was performed at 8 weeks after the injury and no issues were reported by the child’s mother with regards to the elbow.

Figure 1: Anteroposterior and lateral plain radiographs prior to reduction manoeuvre to exclude fracture

Discussion

Young children are prone to sustain pulled elbow largely because of the anatomical features including the shallow, concave radial head, relative plasticity of the cartilage and the immature annular ligament [8]. The usual mechanism of forced-pulling on an extended forearm, commonly seen in the usual age of presentation (1 to 4 years), may not be seen in children under the age of 1 year. This may be due to the fact that generally, a child starts standing and walking at about 1 year of age, so the 1-year-old or older children have a higher physical activity level than the under-1-year-old infants [4]. Rolling over during sleep begins at about 5 months of age. Pulled elbow may occur when the child rolls over without co-ordination, thereby trapping the arm underneath the body [4].

The incidence of pulled elbow is far less common in this age group (under 1-year) and the presentation may be atypical [4]. This leads to difficulty in establishing the diagnosis and the dilemma of performing the reduction manoeuvre in the absence of the typical presentation. The child with this injury may be sitting calm or even be seen playing holding the affected arm with the body. In the usual age group (1 to 4-years), the history of presentation and the findings of clinical examination are considered sufficient for making the diagnosis. Plain radiographs, although not considered necessary, but are important primarily to exclude fractures prior to performing the reduction manoeuvre, in particular in cases of atypical presentation [5, 8]. Obtaining plain radiographs is also important in view of the fact that there have been a few reports of such cases of fractures which were initially misdiagnosed as pulled elbow and the patients were unnecessarily exposed to reduction manoeuvres [4, 9]. On plain radiographs an increased radio-coronoid distance is considered to be the most frequently visible and confirmatory sign of pulled elbow, however, this may be difficult to appreciate in a very young child (< 1 year) [5]. Studies have also reported a valuable role of ultrasonography for establishing the diagnosis of pulled elbow if the presentation and diagnosis remains unclear [7, 8].

When a child is brought with a painful or swollen elbow with lack of movements, with or without a history of an injury, the differential diagnosis, other than pulled elbow, includes supracondylar fracture, olecranon fracture, radial neck fracture, lateral condyle fracture, soft tissue contusion and septic arthritis [3].

Various reduction manoeuvres have been described, of which, two are most commonly practiced. These include supination-flexion, as described above, and hyperpronation, which is performed by holding the child’s elbow at 90° with one hand while firmly pronating the wrist with the other [4, 6, 7]. A debate regarding the choice of reduction method is ongoing in the literature. In a recent Cochrane review of 9 studies (906 patients), Krul et al. found that the hyperpronation method was slightly more effective at first attempt and less painful [7], however overall the studies were found to be of low quality with limited evidence. The failure rate of hyperpronation method ranged from 4.4% to 20.9% (mean 9.2%), and of supination-flexion method ranged from 16.2% to 34.2% (mean 26.4%). Bexkens et al., in another systematic review and meta-analysis with 7 randomized trials from 1998 to 2016 (701 patients), also revealed similar results after reduction of primary and recurrent pulled elbows [10]. Bek et al., in a randomised controlled trial (66 patients), compared the two methods of reduction and found similar rates of final reduction [6].

Successful reduction is indicated by the child’s ability to commence mobilisation of the elbow soon after reduction, regardless of the either method used by the treating physician [3]. However a satisfying ‘click’ is not always heard and is reported in 70% cases [4]. Children with pulled elbow usually respond dramatically to the reduction with a complete resolution of pain and are seen to recover to full function [8]. Temporary immobilisation with a sling for 2 days has been shown to reduce the risk of recurrence, however, the sling may be difficult to tolerate by the younger children [3, 11]. The literature reports an estimated incidence of recurrent pulled elbow of 27% to 39%, mostly among children in first 2 years of life [3]. If neglected, it might, in rare cases, result in a long-term functional disability [3, 8] and might be one of the rare causes of osteochondritis dissecans of the radial head [12].

Conclusion 

Pulled elbow is less common in children under the age of 1 year. A high index of suspicion should be kept in this age group in case of a young child presenting with inability to mobilise the elbow, despite the absence of the usual history of a pulled elbow. After exclusion of a fracture with plain radiographs and administration of sufficient analgesia, the appropriate reduction manoeuvre results in complete resolution of pain and return of full function.

Reference

  1. Choung, W and S.D. Heinrich. “Acute annular ligament interposition into the radiocapitellar joint in children (nursemaid’s elbow)”. Journal of Pediatric Orthopaedics 15.4(1995):454-6.
  2. Schutzman, S.A. and S. Teach. “Upper-extremity impairment in young children”. Annals of Emergency Medicine 26.4(1995):474-479.
  3. Yamanaka, S. and R.D. Goldman. “Pulled elbow in children”. Canadian Family Physician 64.6(2018):439-441.
  4. Irie T., et al. “Investigation on 2331 cases of pulled elbow over the last 10 years”. Pediatric Reports 6.2(2014):5090.
  5. Scapinelli, R. and A. Borgo. “Pulled elbow in infancy: Diagnostic role of imaging”. Radiologia Medica 110.(5-6)(2005):655-664.
  6. Bek, D., et al. “Pronation versus supination maneuvers for the reduction of ‘pulled elbow’: a randomized clinical trial”. European Journal of Emergency Medicine 16.3(2009):135-138.
  7. Krul M., et al. “Manipulative interventions for reducing pulled elbow in young children”. Cochrane Database of Systematic Reviews 1(2012):CD007759.
  8. Mohd Miswan, M.F., et al.”Pulled/nursemaid’s elbow”. Malaysian Family Physician 12.1(2017):26-28.
  9. Kraus R., et al. “Missed elbow fractures misdiagnosed as radial head subluxations”. Acta Orthopaedic Belgica 76.3(2010): 312-315.
  10. Bexkens, R., et al. “Effectiveness of reduction maneuvers in the treatment of nursemaid’s elbow: A systematic review and meta-analysis”. American Journal of Emergency Medicine 35.1(2017): 159-163.
  11. Taha, A.M. “The treatment of pulled elbow: a prospective randomized study”. Archives of Orthopaedic and Trauma Surgery 120.(5-6)(2000): 336-337.
  12. Tatebe, M., et al. “Pathomechanical significance of radial head subluxation in the onset of osteochondritis dissecans of the radial head”. Journal of Orthopaedic Trauma 26.1(2012): e4-6.