Article, Orthopedics

Comparison between new modified external rotation method and external rotation method for reduction of ASD

a b s t r a c t

Introduction: Dislocation of the shoulder joint is common and is mainly anterior. Several Reduction methods have been described and the external reduction method (ERM) is one of the newest. We modified the ERM by making some additions in hopes to develop a less painful, quick and simple method. The aim of this study was to compare the new modified external rotation reduction method (MERM) with ERM in acute anterior Shoulder dislocations (ASD).

Methods: A total of 62 patients with ASD were classified randomly into 2 groups. The reduction was performed with MERM in one group and with ERM in the other group and the results were compared. Patients’ pain scores, reduction time, success rate of the reduction methods, age, sex, dislocation side, dislocation time, previous dislo- cations history, injury mechanism, any complications, reduction time and neurovascular examination were col- lected. Parametric and nonparametric analyses were used to compare MERM and ERM.

Results: The study cohort consisted of 62 patients (52 males, 10 females; mean age, 35 years; age range, 18-73 years) who were randomly assigned to treatment with the MERM (n = 32) or the ERM (n = 30). There was a statistically significant difference between the two methods in terms of time, and the MERM can be applied much faster than ERM (1.34 +- 1.41 min vs 3.05 +- 1.93 min; p b 0.001). The intra-reduction VAS pain score was not significantly in patients who were treated with MERM (85.31 +- 10.39 vs. 78.33 +- 16.54; p = 0.122).

Conclusion: MERM can be an alternate method compared to the ERM for the reduction of ASD.

(C) 2019

Introduction

Shoulder dislocation is one of the most common causes of the joint injuries encountered in the emergency department (ED) [1]. Approxi- mately half of all dislocation cases encountered in the ED are shoulder dislocations [2]. Traumatic shoulder dislocation is generally anterior (nearly 96%) with an incidence of 11.2 to 23.9 per 100,000 person- years [3,4]. Many reduction methods have been described for shoulder dislocation [3-6]. Most of them are painful and have variable success rates [7].

Which method of shoulder reduction is exactly superior is not known. Likewise, it’s important that practitioners have multiple ap- proaches and techniques. The ideal reduction method would be uncom- plicated, fast, effective, painless, and require little assistance or medication [3]. The external rotation method (ERM) that has been known for nearly 30 years and is a safe and reliable method [6,8].

* Corresponding author at: Health Science University Antalya Training and Research Hospital, Kazim Karabekir Street, 07100 Muratpasa, Antalya, Turkey.

E-mail address: [email protected] (C. Bedel).

However, a modification was developed to improve the success rate and reduce complications. We modified the ERM by making some addi- tions in hopes to develop an unpainful, quick and simple method. Tech- nically, the humerus is attached to the trunk in external rotation in our method. We thought to facilitate the reduction by placing an object in the axillary region and lifting the humerus head.

The aim of this study was to compare the new modified external ro- tation reduction method (MERM) with ERM in acute Anterior shoulder dislocation (ASD). The primary outcome was the first attempt success rate. The secondary outcomes were overall success rate, procedural pain, and complications.

Materials and methods

This study was performed to compare the two methods of reduction (MERM and ERM) for ASD between January-December 2016 at a ter- tiary care hospital. Our hospital is a 2000-beds training hospital with ap- proximately 360,000 ED visitors per year. The method to be used in the research was determined as follows: A total of 70 envelopes were iden- tified. ERM forms were placed in half of the closed envelopes where the number was not written on and MERM forms were placed in the other

https://doi.org/10.1016/j.ajem.2019.07.001

0735-6757/(C) 2019

half. All envelopes were collected in a box and mixed. An envelope was drawn each time the patient arrived and the maneuver was determined. ASD was diagnosed with physical examination and radiography at the time of enrollment of the patient. plain radiographs of the conven- tional anteroposterior and transscapular view were obtained before and after the treatment. Complications such as Axillary nerve damage, vascular compromise and Iatrogenic fractures attributable to the reduc-

tion method were also recorded.

All ASD patients between 18 and 75 years of age treated in our hos- pital were considered for inclusion in this study. Patients with hemody- namic instability, multiple trauma, glenoid or intra-articular fracture associated with dislocation, duration of dislocation N24 h, with a history of sedative and anxiolytic medication use before arriving at the hospital, and who were intoxicated were excluded from the study. A study flow- chart can be seen in Fig. 1.

Patients’ pain scores, reduction time, success rate of the reduction methods, age, sex, dislocation side, dislocation time, previous disloca- tions history, injury mechanism, any complications, reduction time and neurovascular examination results were prospectively recorded. Using a Visual analog scale ranging from 0 (no pain) to 100 (worst pain possible), the intensity of pain detected during intra- reduction were recorded. A VAS is usually a 100 mm long horizontal line containing verbal descriptors [9]. In addition, the physician was asked to evaluate the difficulty of implementation between 0 (easy) and 100 (difficult) points.

A total of 5 attending physician were trained for the new MERM method. The physicians had a median post-residency experience time of 5 years (min-max, 2-10 years). The new MERM method training was composed of two parts: a 15-minute lecture and a 1- hour workshop. The training included the anatomy of the shoulder and how this method is applied. During the reduction, one physi- cian performed the method while the other physician asked the pa- tients their level of pain and marked the answer on the VAS scoring system, and also recorded the reduction time. The duration was measured using a mobile phone. Patients were enrolled during the period in which the trained physicians have been working in the hospital.

This study was approved by the local ethics committee. All patients signed an informed consent form.

External rotation method

No anesthesia or analgesia was performed prior to reduction. With the patient in the supine position, without any traction, the elbow was flexed at 90?, then the arm was abducted to side of the chest and the shoulder was placed in 20? forward flexion with grasped wrist. The shoulder was rotated externally from the forearm in the coronal plane, and then, the arm rotated internally and reached across to the chest [8].

Modified external rotation method

On the affected side of the patient, a 5-10 cm, stiff and inflexible ob- ject was placed. The forearm was flexed at 90?, and the arm was flexed 20? forward from the shoulder joint and adducted to the chest. To en- sure the reduction, the arm was slightly externally rotated until the forearm was parallel to the arm and the force was applied to the elbow in a medial direction (Fig. 2a-d). If the patient had pain, the pro- cess was interrupted and repeated in a few minutes. During this process, while the humerus served as a lever arm, the stiff and inflexible object was used as a fulcrum for the lever. Thus, the dislocated humeral head was rotated under the glenoid, while the lever mechanism easily returned to the joint without rubbing against the glenoid and labrum.

We selected the First attempt success rate as the primarily important difference between the two reduction methods in ASD. We estimated that, the mean first attempt success rate (with a two-sided alpha value of 5%, a statistical power of 80% as estimated in an initial study of 30 patients with anterior shoulder dislocation) between the two groups, at least 25 patients had to be recruited. We therefore planned to enroll 30 patients in each group considering an expected failure rate of 20%.

The numeric variables were presented as mean +- standard devia- tion, frequency and percentage, and compared using t-test or Mann- Whitney U tests. The comparison of categorical variables between the MERM and ERM was performed using the Fisher’s exact test, Pearson’s Chi-square test. In addition, data analysis was performed using SPSS for Windows (version 18.0). A p value b0.05 was considered statistically significant.

External rotation (n=30)

Modified external rotation (n=32)

62 Randomised

Excluded (n=18)

Left the study voluntarily after the envelope was selected (n=8)

Age<18 and >75 (n=4) hemodynamic instability(n=0) multiple trauma(n=2)

glenoid or intra-articular fracture(n=3) duration >24h(n=1)

use sedative and anxiolytic(n=0) intoxicated(n=0)

Individuals assessed for eligibility (n=80)

Fig. 1. Study flow diagram.

Fig. 2. a-d) The forearm on the dislocated side is flexed 90? from the elbow. Upper arm raised 20? forward. In the axillary region, a rigid object about 5-10 cm is placed. While the upper arm is slowly rotated externally with the help of the forearm, vertical force is applied from the elbow. The force continues to be applied until the shoulder is in its place.

Results

Eight patients left the study voluntarily after the envelope was se- lected A total of 62 patients (52 males, 10 females; mean age, 35.18 years; age range, 18-73 years) were included in the study. Of them, 32 patients were treated with the MERM, 30 patients with the ERM. There was no statistical significance between age and sex

distributions of patients and modified or ERM (Table 1). A fall on an outstretched hand was the most common mechanism (50%; n = 31), followed by direct trauma and sports injuries. Right ASD was detected in 39 patients (62.9%). Thirty-eight patients (61.2%) had a history of re- current shoulder dislocations. Patients arrived at our ED with a mean time of 1.59 +- 2.59 h after trauma. Patients who underwent ERM ap- plied to the ED significantly later (2.16 +- 3.57 h; p = 0.041). No

Table 1

Baseline characteristics of patients and Shoulder Dislocation Reduction Methods.

techniques. In a retrospective study, a 60% success rate was determined, which was considered to be quite low in our study [14]. In other studies,

Variables Modified external

rotation

External p rotation

this ratio has ranged from 70 to 97% [15-18]. The Results obtained from our study demonstrated higher success rates in both the ERM and

Age, mean (range), years 32(18-63) 34 (18-73) 0.397

MERM than prior studies.

A Successful reduction method is quick and effective for reducing the acute pain. Reduction of a shoulder dislocation by sedation is an ac- cepted and widely used treatment [19]. However, we did not use seda- tion in our study. Although sedation provides comfort to the patient during treatment, it is clear that this may affect the pain score. In addi- tion, sedation can cause nausea, vomiting, heart and respiratory and other systemic problems. The reduction time varies according to each technique and the superiority of any technique has not been clearly

Gender n (%)

Female

4(12.5%)

6(20%)

0.502

Male

28(87.5%)

24(80%)

Number of dislocation

0.298

First dislocation

10(31.2%)

14(46.7%)

Recurrent

22(68.8%)

16(53.3%)

Side

0.793

Right

21(65.6%)

18(60%)

Left

11(34.4%)

12(40%)

Mechanism of dislocation

0.262

Sports injury

5(15.6%)

1(3.3%)

demonstrated so far. Amar et al. have reported reduction duration for

Fall

15(46.9%)

16(53.3%)

Stimson and Milch methods (mean 8.82 min; 4.68 min, respectively)

minor trauma

12(37.5%)

13(43.4%)

Interval from injury to presentation (h)

1.06 +- 0.79

2.16 +- 3.57

0.041

anesthetic or analgesic method was used during reduction methods and there was no patient had any complications such axillary nerve, vascular compromise, and iatrogenic fracture.

Both MERM and ERM techniques achieved first attempt success rates with no statistically significant difference between them (21/ 32;19/30, respectively; p = 0.53; Table 2). Overall success rates were 100% in both groups. The mean time required for the MERM was 1.34

+- 1.41 min, and it was 3.05 +- 1.93 min for the ERM for reduction. There was a statistically significant difference between the two methods in terms of time, and MERM can be performed much faster than ERM (p b 0.001). The intra-reduction VAS pain score was not significantly lower in patients who were treated with MERM (85.31 +- 10.39 vs. 78.33 +- 16.54, p = 0.122) (Table 2). When we ask the physician to score the dif- ficulty of the application; MERM was seen as an easier method com- pared to ERM (20.25 +- 20.68 vs. 33.26 +- 25.34 p = 0.025).

Discussion

ASD is the most common Joint dislocation encountered in ED and can be reduced by several different methods [10-12]. One of these methods, the ERM, is a technique that is reported to be safe, comfortable and reliable [12]. We designed a prospective, randomized study to com- pare the safety, efficiency and reliability of the MERM with the ERM for the reduction of ASD.

In our study, we found a statistically significant difference in favor of the MERM with regard to speed of reduction. The success rate of these two methods after a maximum of three trials was 100%. In addition to the high success rate, the absence of iatrogenic injuries would affect the use of a maneuver as the first choice [13]. In this study, no complica- tion was observed in any of the patients.

One of the important findings of this study was the high success rate of the self-reduction technique, which is comparable to other

Table 2

Success rate, reduction time and pain scores of MERM and ERM for reduction.

[20]. In another study by Chung et al., the reduction duration for Chair and Kocher methods were 3 min and 5 min respectively [21]. Sayegh et al. have found that the reduction duration in the Kocher was

4.3 min [16]. In our study, both MERM and ERM had shorter reduction durations than the aforementioned studies. The mean time required for the MERM was 1.34 +- 1.41 min, and it was 3.05 +- 1.93 min for ERM for reduction.

One of the most important features of shoulder dislocation tech- niques is limiting pain. The VAS is a method generally used for measur- ing pain, however, studies that measure pain with VAS are limited. Amar et al. have reported that the patients’ pain at the arrival to the ED has ranged from 0 to 10 (mean 7.36) on VAS. In their study, they have found the VAS score with a mean of 5.38 during the reduction [20]. In another study comparing Chair, Kocher, Matsen and Spaso methods, the VAS scores have been found as 4.0, 6.9, 6.8, and 6.5, re- spectively [3]. In our study, the intra-reduction VAS pain score was sig- nificantly lower in patients who were treated with MERM (85.31 +- 10.39; 78.33 +- 16.54, p = 0.122, respectively). In addition to the other studies, in our study, the physicians evaluated the difficulty of the method MERM as an easier method compared to ERM. The differ- ence in pain scores may have been due to our study not providing anal- gesia or anesthesia.

In a study, the patient sitting on a chair and the physician standing behind him or her. The physician positioning one fist in the anterior part of the axillary fossa for countertraction but avoiding direct pressure into the axillary fossa, the other hand uses traction grasping the patient’s forearm. [22]. Although Muscle relaxation with the idea of armpit support was similar to our study, it was quite different from our study in terms of posture position and maneuver. In another study, the physicians insert the patient’s flexed forearm into the axilla of the affected shoulder and pull the head of the humerus into the socket [23]. However, it was different from our study by the use of anes- thesia and by not rotating the patient’s arm. Mimura et al. have pre- sented a new method in which the shoulder adducted as far as possible by pushing the medial side of the upper arm under both trac- tion and internal rotation [24]. The most important difference of this method from our study was that the support was not applied to the ax- illary region.

The limitations of the study were small sample size and the results are obtained from only one center. Because of the small number of pa- tients in our study group, it may be necessary to study with more pa-

Variables Modified external

rotation

Overall success rate (%)

100%

100%

0.982

Reduction time (min)

number of attempts (% of patients) First attempt

1.34 +- 1.41

21(65.6%)

3.05 +- 1.93

19(63.3%)

b0.001

0.864

Second attempt

7(21.9%)

7(23.3%)

Third attempt

4(12.5%)

4(13.4%)

External p rotation

tient numbers in order to demonstrate the success of the method. The MERM and ERM were not compared with other reduction methods. Al- though our method was an alternative method for shoulder dislocation, we could not prove its usability as the first choice because it was not compared with the other reduction methods. There were only 5 physi- cians in the study and these physicians had extensive experience. Since children and elderly patients were not included in the study, the appli-

Intra-reduction VAS

85.31 +- 10.39

78.33 +- 16.54

0.122

cability of this method to these populations is unknown. Finally, al-

Difficulty level for physician

20.25 +- 20.68

33.26 +- 25.34

0.025

though there is a significant difference between the groups at the

Abbreviation: VAS: Visual analog scale.

interval from injury to the application, a prospective comprehensive

study is needed as there are many personal and social factors that may affect this situation.

We plan to make a prospective randomized study in the future, com- paring the MERM with other conventional reduction methods such as Kocher, Milch, FARES, Hippocrates and Stimson technique, in order to determine precisely the method’s superiority to all other methods.

In conclusion, we found that the MERM, compared to the ERM, is sig- nificantly faster and relatively similar painful for non-sedated ED pa- tients with ASD. MERM can be an alternate method compared to the ERM for the reduction of ASD.

Funding sources

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

Declaration of Competing Interest

The authors have no conflicts of interest.

References

  1. Gul M, Yavuz U, Sokucu S, Cetinkaya E, Arikan Y, Kabukcuoglu YS. Flexion-adduc- tion-external rotation method for shoulder dislocations. Acta Orthop Traumatol Turc 2014;48(2):164-8.
  2. Dugas JR, Crozier MW. Traumatic anterior instability: treatment options for initial in- stability. Sports Med Arthrosc Rev 2018;26(3):95-101.
  3. Guler O, Ekinci S, Akyildiz F, Tirmik U, Cakmak S, Ugras A, et al. Comparison of four different reduction methods for anterior dislocation of the shoulder. J Orthop Surg Res 2015;10(1):80.
  4. Zacchilli MA, Owens BD. Epidemiology of shoulder dislocations presenting to emer- gency departments in the United States. J Bone Joint Surg Br 2010;92(3):542-9.
  5. Alkaduhimi H, van der Linde J, Willigenburg N, van Deurzen D, van den Bekerom M. A systematic comparison of the closed shoulder reduction techniques. Arch Orthop Trauma Surg 2017;137(5):589-99.
  6. Marinelli M, de Palma L. The external rotation method for reduction of acute anterior shoulder dislocations. J Orthop Traumatol 2009;10(1):17-20.
  7. Robinson C, Kelly M, Wakefield A. Redislocation of the shoulder during the first six weeks after a primary anterior dislocation: risk factors and results of treatment. J Bone Joint Surg Br 2002;84(9):1552-9.
  8. Plummer D, Clinton J. The external rotation method for reduction of acute anterior shoulder dislocation. Emerg Med Clin North Am 1989;7(1):165-75.
  9. Kersten P, Kucukdeveci AA, Tennant A. The use of the Visual analogue scale (VAS) in rehabilitation outcomes. J Rehabil Med 2012;44(7):609.
  10. Beattie T, Steedman D, McGowan A, Robertson C. A comparison of the Milch and Ko- cher techniques for acute anterior dislocation of the shoulder. Injury 1986;17(5): 349-52.
  11. Manes HR. A new method of shoulder reduction in the elderly. Clin Orthop Relat Res

    1980;147:200-2.

    Eachempati KK, Dua A, Malhotra R, Bhan S, Bera JR. The external rotation method for reduction of acute anterior dislocations and fracture-dislocations of the shoulder. J Bone Joint Surg Br 2004;86(11):2431-4.

  12. Regauer M, Polzer H, Mutschler W. Neurovascular complications due to the Hippoc- rates method for reducing anterior shoulder dislocations. World J Orthop 2014;5(1): 57-61.
  13. Ceroni D, Sadri H, Leuenberger A. Anteroinferior shoulder dislocation: an auto- reduction method without analgesia. J Orthop Trauma 1997;11(6):399-404.
  14. Russell JA, Keller D. Reduction of acute anterior shoulder dislocations using the Milch technique: a study of ski injuries. J Trauma 1981;21(9):802-4.
  15. Sayegh FE, Kenanidis EI, Papavasiliou KA, Potoupnis ME, Kirkos JM, Kapetanos GA. Reduction of acute anterior dislocations: a prospective randomized study comparing a new technique with the Hippocratic and Kocher methods. J Bone Joint Surg Br 2009;91(12):2775-82.
  16. Simonet WT, Cofield R, Ilstrup D. Incidence of anterior shoulder dislocation in Olm- sted County, Minnesota. Clin Orthop Relat Res 1984(186):186-91.
  17. Gnawali GP, Dhakal I, Khatri K, Sharma S. The efficacy of external rotation method for the reduction of acute anterior shoulder dislocation with and without greater tu- berosity fracture. Birat J Health Sci 2018;3(2):408-12.
  18. Shields DW, Jefferies JG, Brooksbank AJ, Millar N, Jenkins PJ. Epidemiology of glenohumeral dislocation and subsequent instability in an urban population. J Shoulder Elbow Surg 2018;27(2):189-95.
  19. Amar E, Maman E, Khashan M, Kauffman E, Rath E, Chechik O. Milch versus Stimson technique for nonsedated reduction of anterior shoulder dislocation: a prospective randomized trial and analysis of factors affecting success. J Shoulder Elbow Surg 2012;21(11):1443-9.
  20. Chung JYM, Cheng CH, Graham CA, Rainer TH. The effectiveness of a specially de- signed shoulder chair for closed reduction of acute shoulder dislocation in the emer- gency department: a randomised control trial. Emerg Med J 2013;30(10):795-800.
  21. Walz M, Kolbow B, Auerbach F. Eine schonende Methode zur Reposition der vorderen Schulterluxation. Unfallchirurg 2006;109(7):551-5.
  22. Gnawali GP, Dhakal I, Khatri K, Sharma S. The Efficacy of External Rotation Method for The Reduction of Acute Anterior Shoulder Dislocation With and Without Greater Tuberosity Fracture. Birat J Health Sci 2018;3(2):408-12.
  23. Mimura T, Mori K, Matsusue Y, Tanaka N, Nishi Y, Kobayashi M. Closed reduction for traumatic posterior dislocation of the shoulder using the ‘lever principle’: two case reports and a review of the literature. J Orthop Surg (Hong Kong) 2006;14(3):336-9.