Dislocated Shoulder: Approaches to Lessen The Pain of Reduction Techniques
The extensive mobility of the glenohumeral joint lends itself to frequent injury, particularly anterior shoulder dislocations. Shoulder dislocations account for 45% of all joint dislocations.1 Routine treatment involves reduction of the humeral head back into the glenohumeral joint. Many reduction techniques are available, including the Milch, Kocher, Stimson, and Bosley techniques. If one technique fails, physicians can switch to another technique without having to reposition the patient, thus avoiding additional pain.2
For many patients, the most urgent complaint in the emergency department (ED) is excruciating pain during reduction. Several methods are available to relieve this pain, including IV medication with midazolam-fentanyl (conscious sedation) or propofol (deep sedation), intra-articular lidocaine, inhaled nitrous oxide and oxygen (Entonox), and brachial plexus blocks.
Currently, there is no consensus among physicians as to which technique provides the most effective and least harmful medication for reduction. A combination of factors are considered when choosing analgesia, such as cost; need for monitoring after the procedure; available personnel; physician’s preference, experience with reduction technique, and experience using analgesia; and any comorbidities the patient may present with, such as osteoporosis and/or humeral fractures.2 Certain reduction techniques, however, require no premedication because they do not inflict pain on the patient while being performed.3,4
The objective of this article is to evaluate the various methods and medications for managing pain when reducing dislocated shoulders.
Painless Reduction Without Anesthesia
In managing a patient with an anterior dislocated shoulder, a few techniques have been shown to be effective without the use of any medication for pain relief. These include the Kocher and Milch techniques.5 Theodore Kocher described his technique in 1870 by saying, “Bend arm at the elbow, press it against the body, rotate outwards until resistance is felt. Lift the externally rotated upper arm in the sagittal plane as far as possible forwards and finally turn inwards slowly.”5-7 These movements physiologically help to relax the biceps and stretch the internal rotators, which allows the humeral head to fall into place.7 In a study by Anand et al, 16 of 16 shoulder dislocations were successfully reduced using the Kocher technique without the need for sedation or analgesia.5
Although it generally is performed without analgesia, modifications in the technique have required the use of analgesia and sedation at times. Kocher did not include traction in his original technique, and when applied it generates excessive pain by stretching soft tissue and inducing muscle spasms, which necessitate the use of medication.5-7
The Milch technique is another painless method used to reduce anterior dislocated shoulders. First described in 1938, this technique combines abduction, traction, and pressure on the humeral head. In order to reduce a dislocated shoulder using the Milch technique, the physician stands on the side of the dislocated shoulder and first places the elbow into flexion. The arm is then abducted and externally rotated as the physician grasps the humeral head to keep it steady. The humeral head is then pushed back into the axilla with direct pressure from the physician’s grasp. The idea behind these maneuvers is that the forces created by the muscles cancel each other out, thus reducing stress and creating a resultant force that is parallel to the shaft of the humerus.2,7,8 A 1986 study by Beattie et al found that 72% of patients treated with the Milch technique were successfully reduced on first attempt, did not require medication, and had no postprocedural complications.9
When the two techniques are compared, the Kocher method has been associated with complications such as surgical neck fractures due to physicians attempting to overcome muscle spasms. Other disadvantages of this technique include difficulty in positioning obese patients, spiral fractures in the shaft of the humerus, axillary nerve injuries, and increased likelihood of recurrent dislocations (see Table 1). Alternatively, the Milch method has been reported to be a painless procedure that does not cause various complications and trauma to the humerus.7 However, both techniques offer the advantages of quick recovery, less time spent in the ED, and a decreased need for medical staff to monitor patients.10
Interscalene Brachial Plexus Block
Interscalene brachial plexus blocks, first described in 1970, are a relatively new method of anesthetizing the shoulder prior to surgery and reduction of dislocated shoulders. Underhill et al performed interscalene brachial plexus blocks on 30 dislocated shoulders, of which 29 were anterior and 1 was posterior.11 The block was performed by turning the patient’s head away from the affected side and then palpating for the interscalene groove along the lateral aspect of the anterior scalene muscle, which contains elements of the brachial plexus nerves that are necessary to block for anesthesia to the shoulder and arm. Of the 30 cases that were performed, 26 blocks were successful at abolishing or relieving pain, muscle relaxation, and reducing the dislocated shoulder using a mixture of 1% lidocaine, adrenaline, and 0.5% prilocaine. Many of the blocks had worn off before the patients left the ED and did not require intense monitoring by medical staff.11
Many anesthesiologists perform interscalene blocks for shoulder surgeries and use nerve stimulators that produce twitches of the biceps, triceps, and deltoid muscle, which helps to identify the proper location to administer the block. Newer technology has allowed for ultrasound guidance when administering interscalene blocks rather than the use of less accurate landmarks in determining the site of the block.12 Complications of the block (see Table 1) include transient Horner’s syndrome, hoarseness due to recurrent laryngeal nerve palsy, phrenic nerve palsy, and vascular bleeding due to the misplacement of the needle.11 These nerve blocks also have a potential risk for joint infection if sterile technique is not used.2 Several benefits include the relatively quick onset; lack of need for continuous or long-term monitoring; absence of conscious sedation, which may predispose a patient to aspiration and hypoxia; and the ability to also relax the muscles surrounding the joint.11