Nursemaid's Elbow - Supination-flexion Technique Versus Hyperpronation/forced Pronation: Randomized Clinical Study.

BACKGROUND: Nursemaid's elbow (NE) represents the most common pathology met in the pediatric orthopedics ambulatory. There are two techniques of reducing the NE: the supination-flexion technique and the hyperpronation or forced pronation technique.
MATERIALS AND METHODS: In this randomized clinical study, we aim to compare the two reduction techniques of the NE, by measuring the effectiveness of each and scaling the pain felt by the child, by using the Faces Pain Scale. The study included 116 patients with typical presentation for NE with age under 7 years old (mean age ~3 years old), 45% of males and 55% of females.
RESULTS: Hyperpronation was found to be more successful than supination-flexion technique as a first attempt (85% vs. 53%), second attempt (50% vs. 28%), and as a crossover technique (100% vs. 50%) when supination-flexion failed.
CONCLUSIONS: This study concludes that hyperpronation technique should be used as a first maneuver reduction in treating NE, a simple one-movement technique.

Introduction

Nursemaid's elbow (NE) or radial head subluxation represents the most common pediatric pathology met in pediatric orthopedic ambulatory under the age of six,1 representing about 20% of upper-extremity conditions.2

The typical mechanism of injury includes axial traction on a pronated forearm that occurs during play or during common activities.3 Following this traction, radial head subluxation occurs and the annular ligament is entrapped in the radiohumeral joint.45 The typical clinical presentation includes pain of the forearm, limited movement of the elbow/forearm, the superior limb hangs near the body with the elbow slightly flexed, and forearm blocked in pronation.67

There are two techniques of reducing the NE: the supination-flexion technique and the hyperpronation or forced pronation technique.

The hyperpronation technique was first described by Hutchinson in 188689 and it is believed to be less painful and more successful if used as the first reduction attempt,1011121314 although a recent Cochrane review15 found low-quality evidence to sustain the benefits of this reduction method. The hyperpronation maneuver is depicted in Figure 1. The hyperpronation technique is performed as follows: the patient stays on the parent's lap facing the examiner; grabbing the elbow with one hand, the examiner's opposite hand firmly grabs the distal forearm as shown in Figure 2 and applies the hyperpronation as shown in Figure 3. During these maneuvers, a clank will be felt, a sign that the radial head has reentered into the annular ligament.1016

Figure 1

Hyperpronation maneuver

Figure 2

Hyperpronation maneuver – step 1

Figure 3

Hyperpronation maneuver – step 2

Most pediatric and orthopedic textbooks recommend the supination-flexion technique.671718 The supination maneuver is shown in Figure 4. The technique is performed as follows: the patient stays on the parent's lap facing the examiner; grabbing the elbow with one hand, the examiner's opposite hand firmly grabs the distal forearm as shown in Figure 5 and applies the supination of the forearm as shown in Figure 6 followed by the flexion as shown in Figure 7. During these maneuvers, a clank will be felt, a sign of the radial head's entry back into the annular ligament.7101112

Figure 4

Supination-flexion maneuver

Figure 5

Supination-flexion maneuver – step 1

Figure 6

Supination-flexion maneuver – step 2

Figure 7

Supination-flexion maneuver – step 3

Objectives

In this randomized clinical study, we aim to compare the two reduction techniques of the NE, by measuring the effectiveness of each one and scaling the pain felt by the child, by using the Faces Pain Scale.1920

Materials and Methods

The study was done at the pediatric orthopedic emergency department of an emergency hospital located in an urban area between February 2016 and February 2017.

We chose to conduct a prospective, unblinded, interventional, randomized controlled study. The study included children with age under 7 years old with typical clinical presentation and case history for NE (pain experienced in the forearm, limited movement of the elbow/forearm, the upper limb hanging near the body with the elbow slightly flexed, and pronated forearm, usually with a history of someone who pulled/lifted/swung/caught the child by the hand). Patients that had any traumatic injury such as falls, hits, or any other signs of trauma and fractures (soft-tissue swelling, redness, and local deformity) were excluded from the study.

A local ethical committee approved this study. An informed consent was obtained from the parents of all the participants. The reduction was performed by a pediatric orthopedist, in the emergency room. All the doctors in the department were previously trained in order to follow the same reduction protocol. Patients were asked if they received pain killers at home, but none received any.

The patients were randomized by odd and even numbers. Every odd-numbered patient received the supination-flexion technique (Group A), while the even-numbered patient received the hyperpronation technique (Group B).

The patients were reevaluated after 10 min. The initial procedure was repeated if the first attempt failed. Then, we waited for another 10 min. If the second attempt failed, it resulted in a crossover to the alternate method for the third attempt. If the patient failed both techniques, plain X-ray of the forearm and elbow was performed [Figure 8]. If the radiography showed no abnormality, but the patient refused to move his elbow, then the patient was immobilized in a long-arm cast for 1 week. The flowchart of the randomization process is shown in Figure 9.

Figure 8

X-ray of a Nursemaid's elbow, before the reduction

Figure 9

Flowchart of patients

The pain was evaluated using the Faces Pain Scale, after the reduction. A different pediatric orthopedist doctor (not the one who performed the reduction) did the evaluation.

Demographic data, technique success, and pain levels were analyzed statistically. Gender was analyzed using the Chi-square test. The efficacy of the techniques was analyzed using Fisher's exact test. The comparisons of pain levels were analyzed using the average score. Statistical significance was determined using P < 0.05 at a 95% confidence interval. Analyses were performed with the SPSS 18.0 software (IBM Corporation, USA).

Results

Among the 155 patients that presented with suggestive clinical signs for NE, 116 were selected for the study. Fifteen patients were excluded for having suspicious case history and local edema; eight patients were older than 7 years old and did not meet the inclusion criteria and 16 patients declined participation to the study and refused written consent.

The median age was 34 months, ranging from 6 to 83 months (~6.9 years). Fifty three (45.68%) patients were males, while 63 (54.31%) were females. Among the 116 patients, 114 were treated with one of the reduction techniques; two patients complained of persistent pain after the reduction and a long-arm cast was used for 1 week. After this period, the cast was removed and the range of motion of the elbow/forearm was evaluated and found to be painless and normal. The demographic data of the patients is summarized in Table 1.

Table 1

Demographic data

Patients	Supination-flexion	Hyperpronation	P
Male	28	25	0.826
Female	32	31
Under 3 years	23	33	0.765
Over 3 years	9	15
Recurrent	8	17	0.969
New cases	24	31

A total of eighty patients (68.96%) were successfully reduced after the first attempt, using one of the two techniques.

We divided the study into two groups: a group with patients under 3 years of age and the other group with patients older than 3 years of age. The results after reduction were compared in order to establish if the success of the methods is age related, but these results were not statistically significant [Table 1].

Thirty one percent (25) of the patients had, based on memory, recurrent episodes of pulled elbow. Having a positive history for NE did not influence the success of the reduction, as summarized in Table 1.

The supination-flexion technique was used as the first choice of reduction for sixty patients (51.72%) (Group A). Thirty two patients (53.33%) were properly reduced after the first attempt, using this technique. Eight patients (13.33%) were reduced after the second attempt. Twenty patients (33.33%) were reduced using the alternative method, when the first two reduction attempts had failed.

The hyperpronation technique was used as the first choice of reduction for 56 patients (48.27%) (Group B). Forty eight (85.71%) patients were reduced in the first attempt using this technique. Four patients (14.28%) were reduced in the second attempt and four patients (7.14%) underwent the alternative method in a third attempt. Two patients needed cast immobilization because of persistence of pain.

The supination-flexion technique was applied to 42 out of 64 patients, while the hyperpronation technique was applied to 72 out of 76 patients. Table 2 summarizes the success rates of both techniques.

Table 2

The efficacy of the reduction techniques based on the number of attempts

Attempts	Reduction maneuver				Total	χ2	P
	Supination-flexion (n=60), n (%)		Hyperpronation (n=56), n (%)
	Successful	Unsuccessful	Successful	Unsuccessful
First attempt	32/60 (53.33)	28/60 (46.66)	48/56 (85.71)	8/56 (14.18)	116	19.548	0.00001
Second attempt	8/28 (28.57)	20/28 (71.42)	4/8 (50)	4/8 (50)	36	-	0.25
Third attempt	2/4 (50)	2/4 (50)	20/20 (100)	-	24	-	-
Total	42/92		72/76		116		0.00

Evaluation of pain levels was done for 95 patients, older than 1 year. This evaluation was performed after the first attempt of reduction only.

Using the Faces Pain Scale, we noticed an average score of 5.9 for supination-flexion technique, while the hyperpronation technique achieved a score of 5.3. The results were not statistically significant.

Discussion

In medical textbooks, the supination-flexion technique is suggested to be the main reduction maneuver for NE.672122 However, there are studies that consider hyperpronation to be more effective not only as a first attempt, but also as a crossover technique when supination-flexion failed.101113

One of the studies reports a 95% success rate for hyperpronation method from the first attempt versus 77% for the supination method and concluded that the hyperpronation method was more successful as a crossover maneuver, enrolling a total of ninety patients.10 Another study that enrolled 148 patients reported 80% success rate for hyperpronation and 69% for the supination maneuver and concluded that hyperpronation may be less painful if used as a first attempt technique.11 In their randomized study on 66 patients, Bek et al. achieved a success rate of 94% for hyperpronation and 69% for the supination maneuver. The authors stated that the hyperpronation maneuver is easier to be performed by the physicians and less painful for the children.13 In our study, we noticed that hyperpronation was more successful in comparison with supination-flexion method, as a first attempt and as a crossover technique.

We choose the Faces Pain Scale to evaluate the pain after the reducing maneuver. Other studies used different pain scales such as Wong–Baker Pain Scale,11 mCHEOPS,23 the standard Visual Analog Pain Scale,12 and the Faces Pain Scale.1920

Referring to the pain scale, McDonald et al. noted the score provided by the parents and physicians using the Wong–Baker scale,11 which is prone to be subjective. Gunaydin et al., using the mCHEOPS scale, had another physician who recorded the pain level in order to obtain more conclusive results.23 In their study, Green et al. had recorded the pain level using a standard Visual Analog Pain Scale from parents, nurses, and physicians before, during, and 1 min after the reduction.12 The scores reported by the physicians were similar for the two maneuvers, but nurses and parents recorded better scores with hyperpronation hence being perceived less painful. In our study, the pain felt by the child while using the hyperpronation technique was lower than that using the supination technique, but the difference was not statistically significant. Some studies reported better results using the hyperpronation method and noticed that this maneuver was less painful as reported by nurses and parents.122224

Pain monitoring in children is difficult and the quantification is often subjective.23 Hyperpronation technique of the forearm requires lesser steps than supination-flexion method. This could be a possible explanation for the reduction success, with less pain cited in many studies. Parents could be educated on how to safely perform the maneuver if the situation repeats.

Some study limitations can be observed. For example, just by comparing the pain felt by a 1-year-old child with a 5-year-old child cannot be correctly assessed by this score, mostly because the level of understanding is better at 5 years old than at 1 year old. In addition, patients under 1 year of age were excluded as not being part of the Faces Pain Scale inclusion criteria.

A limitation of the study consists of the randomization criteria. A randomization in a same age population could be done in a power study, which has a more clear impact on the success rate of the technique and the amount of pain at the first reduction attempt.

Another limitation of the study is that we could not quantify the time that passed by since the radial head subluxation occurred until the reduction maneuver was performed, and what was the impact of this on the amount of pain and the success of the reduction. We noticed that delayed cases, as far as 2 or 3 days old, are harder to be reduced and the patient experiences more pain after the reduction.

Conclusions

Hyperpronation was found more successful than supination-flexion technique as a first attempt (85% vs. 53%), second attempt (50% vs. 28%), and as a crossover technique.

Even if the pain scores are not statistically significant, in our opinion, hyperpronation was less painful for the patient, but further studies should be done comparing same-age patients in order to obtain a power study.

This study concludes that hyperpronation technique should be used as a first reduction maneuver in treating NE, a simple one-movement technique.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patients have given their consent for their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.