Intra-articular Shoulder Injection for Reduction Following Shoulder Dislocation
Source: Rachel Liu, BAO, MBBCh, Emergency Medicine, Yale School of Medicine, New Haven, Connecticut, USA
The anterior shoulder dislocation is one of t…
1. Physical Exam Findings
- On general inspection, observe the patient for the loss of shoulder contour and flattened shoulder definition compared with the unaffected side. This occurs because the humeral head is no longer beneath the deltoid. Notice if the patient rests with the arm held in slight abduction and external rotation, supporting the arm with the uninjured hand. These are signs of an anterior dislocation.
- Palpate the radial pulse. Although injury to the axillary artery is rare from a dislocation, a decreased or absent radial pulse can be a clue, especially if the injury occurs in an elderly patient.
- Palpate along the clavicles of both sides (affected and unaffected), outward towards the shoulders, to determine if there is any pain or deficit that points to a clavicular injury.
- Palpate for the humeral head. In a dislocated shoulder, it is often felt in the lateral subclavicular region anterior to the armpit.
- Assess the status of the axillary nerve by testing sensation over the lateral upper arm in the "regimental badge" area of the deltoid muscle. The axillary nerve is the most common nerve injury associated with anterior shoulder dislocations, and sensory losses are usually temporary.
- Test the rest of the brachial plexus by performing sensory and strength examinations of the hand, wrist, and elbow while supporting the patient's shoulder. Brachial plexus injuries are rare, but may occur if a stretch injury is the reason for dislocation.
- Record any deficits found on examination in range of movement, sensation, or motor strength to establish a baseline. These will need to be retested once the procedure is complete to evaluate for any changes. Large sensorimotor deficits, or worry for involvement of brachial plexus branches, may be an indication for operative management.
- Obtain an anteroposterior, lateral, and "Y view" shoulder X-ray to rule out fractures.
2. Procedure Without Ultrasound
- Equipment needed: betadine solution, sterile gloves, 1% lidocaine, a 20 mL syringe, 20-gauge 3.5 cm needle, gauze, tape, sterile tray to place equipment
- Place the patient in a sitting or semi-recumbent position, as this is usually the most tolerable position for patients with anterior shoulder dislocation.
- Palpate the surface landmarks of the posterior acromion, coracoid, and the lateral sulcus. The lateral sulcus is an abnormal finding associated with anterior shoulder dislocation; it is formed by the empty glenoid fossa when the humeral head has vacated that space. Press into the shoulder from the posterolateral or lateral side, and the sulcus will be evident by finger intrusion into the space or depression of the skin. This will be the insertion site for the analgesia.
- Mark the insertion site by placing an "X" over the spot with a skin marker. Apply betadine generously over the site in a sterile fashion.
- Prepare the syringe with 10-20 mL of lidocaine 1%, and attach a needle to the syringe.
- Don sterile gloves, and palpate the anticipated insertion site again to confirm the point of entry.
- Insert a small wheal of subcutaneous lidocaine to anesthetize the skin. Direct the needle about 2 cm inferior and lateral to the acromion in the lateral sulcus, toward the shoulder joint. Slowly proceed deeper, injecting a small amount of lidocaine into the tract of subcutaneous tissue and muscle.
- Aspirate intermittently. Once you have broached the injured joint capsule, serosanguinous fluid should be freely aspirated. At this point, slowly inject 10-20 mL of lidocaine.
- If the needle has been inserted all the way in, but no blood has been aspirated, this means that either you are not in the correct space, or the needle is not long enough. Do not inject more lidocaine as it will not be effective. If this happens, you can attempt to repeat the procedure using a longer needle (this sometimes requires a spinal needle) or use ultrasound guidance as described below.
- Once lidocaine has been inserted into the shoulder joint, wait 10-15 minutes and assess if the patient is more comfortable and numb in the shoulder.
- Proceed with shoulder reduction.
3. Procedure Using Ultrasound Guidance
- It is usually helpful to have an assistant, as one person holds the ultrasound probe and the other performs the injection; however, it is not entirely necessary.
- Using the linear probe (for a thin person) or the curvilinear probe (for a larger person), place the probe in a transverse plane across the dorsal aspect of the affected shoulder. On the ultrasound screen, look for anterior displacement of the humeral head away from the glenoid. In the evacuated glenoid fossa in between the glenoid and the humerus, you will see clot formation.
- Sterilize the lateral shoulder using betadine.
- Prepare the syringe with 10-20 mL of lidocaine, attaching the needle. Don sterile gloves.
- Inject a superficial wheal of lidocaine to anesthetize the skin at the insertion site on the lateral or posterolateral aspect of the shoulder. Proceed deeper slowly, injecting a small amount of lidocaine into the subcutaneous tissue and muscle.
- Follow the needle tip on the ultrasound screen as it enters in an "in plane" approach, meaning that the direction of needle insertion is parallel to or in plane with the direction of probe orientation.
- Direct the needle tip towards the blood clot in the empty glenoid fossa. When the needle tip is seen within the joint capsule, aspirate. Aspiration will be visible on the screen and confirmed with blood in the syringe.
- Inject 10-20 mL of lidocaine into the joint space. This will be visible as a "swirling" motion on the ultrasound screen.
- Wait 10-15 minutes and assess the effect of intra-articular anesthesia by asking the patient if the pain has decreased.
- Proceed with shoulder reduction and confirm correct humeral head placement in line with the glenoid by ultrasound.
Intra-articular injection with a local anesthetic offers significant pain relief in patients with shoulder dislocation.
The dislodgment of humerus from the scapula is a painful injury that leads to loss of active abduction... adduction... and internal rotation. Reduction is the best form of analgesia, and of course, is necessary to restore of arm function. But the procedure for this restoration can be extremely painful. Therefore, before attempting the repair, injecting a local anesthetic into the intra-articular space decreases pain perception and eliminates the need for complete sedation for the reduction process.
This video will illustrate the intra-articular injection procedure performed in the absence and presence of ultrasound guidance.
Before going into the details of the procedure, let's briefly review the types and etiology of shoulder dislocation.
The anatomy of the shoulder joint provides both extensive range of motion and considerable instability, making shoulder dislocation one of the most common joint disarticulations seen in emergency settings. The three major types of shoulder dislocations are: anterior, posterior, and inferior. Anterior shoulder dislocation is most typical accounting for almost 95% of the cases. This could be further classified into four types: subcoracoid, subglenoid, subclavicular, and intrathoracic. Of all the anterior shoulder dislocation cases, 75% are subcoracoid, and about 20% are subglenoid, leaving 5% for the other two types combined.
With this knowledge, let's review how to perform intra-articular injection technique in the absence of ultrasound guidance.
After performing the physical exam and analyzing the X-ray confirming anterior joint dislocation, gather all the equipment needed for the procedure. These include: betadine solution, sterile gloves, 1% lidocaine, 20 ml syringe, 20 gauge 3.5 cm needle, gauze, tape, and a sterile tray to place the equipment.
Next, place the patient in a sitting or semi-recumbent position, as these positions are typically tolerable in case an anterior shoulder dislocation. Once the patient is as comfortable as injury allows, palpate the surface landmarks of the posterior acromion and the coracoid, and look for the newly formed lateral sulcus, which is an abnormal finding in presence of an empty glenoid fossa associated with anterior shoulder dislocation. Press into the shoulder from the posterolateral or lateral side and the sulcus will be evident by finger intrusion into the space or depression of the skin. This will be the insertion site for the injection. Mark this site with a skin marker. Next, apply antiseptic solution generously over the site in sterile fashion. Following that, prepare a syringe with 10-20 mL of 1% lidocaine, and attach an appropriate needle.
At this point, don sterile gloves, and palpate the anticipated insertion site again to confirm the point of entry. Now insert a small wheal of subcutaneous lidocaine to anesthetize the skin. Thendirect the needle about 2 cm inferior and lateral to the acromion in the lateral sulcus, toward the shoulder joint. Proceed deeper slowly, injecting a small amount of lidocaine into the tract of subcutaneous tissue and muscle.Aspirate intermittently, and when you have broached the injured joint capsule, serosanguinous fluid will be seen in the syringe.
At this point, slowly inject the remaining lidocaine. If the needle has been inserted all the way in but no blood has been aspirated, this means that either you are not in the correct space, or the needle is not long enough. Do not inject more lidocaine, as it will not be effective. If this happens, you can attempt to repeat the procedure using a longer needle -- sometimes this procedure requires a spinal needle -- or use of ultrasound guidance as described in the next section.
Now let's review the same procedure under ultrasound guidance.?
The linear probe is more suitable for a thin person, and the curvilinear probe is apt for a larger person. Place the probe in the transverse plane across the dorsal aspect of the affected shoulder. In a normal shoulder, the humeral head will be in contact with the glenoid and ultrasound imaging will reveal both structures adjacent to each other in the same imaging plane. In case of anterior displacement, look for of the humeral head away from the glenoid. In the evacuated glenoid fossa in between the glenoid and the humerus, you will see clot formation, or hemarthrosis.
Like before, sterilize the lateral shoulder using an antiseptic, prepare the syringe and don sterile gloves. Now under ultrasound guidance, inject a superficial wheal of lidocaine to anesthetize the skin at the insertion site on the lateral or posterolateral aspect of the shoulder. Proceed deeper slowly, injecting a small amount of lidocaine into the subcutaneous tissue and muscle. Follow the needle tip on the ultrasound screen as it enters in an "in plane" approach -- meaning that the direction of the needle insertion is parallel to or "in plane" with the direction of probe orientation. Direct the needle tip towards the blood clot in the empty glenoid fossa. When the needle tip is seen within the joint capsule, aspirate. Blood in syringe would confirm that the location is accurate. Now inject 10-20 mL of lidocaine into the joint space. This will be visible as a "swirling" motion on the ultrasound screen.
Wait 10-15 minutes and assess the effect of intra-articular anesthesia by asking the patient if their pain has decreased. If an adequate level of anesthesia has been achieved, proceed with shoulder reduction. Lastly, confirm correct humeral head placement in line with the glenoid by ultrasound.
"One of the main reasons for not achieving an adequate analgesia using this procedure is, not accessing the joint capsule due to inadequate needle length in the patients with large musculature or obese individuals. Regular needles may be too short to pierce through the subcutaneous tissue, and the procedure may require a longer 22 gauge spinal needle in these patients."
"The other complication is that the author may report meeting resistance during the procedure. This may be due to inappropriate trajectory of the needle insertion causing it to abut against the bony prominence. This can be avoided by performing the injection under the ultrasound guidance, which helps to determine the appropriate pathway and increases the success of the procedure."
You've just watched JoVE's illustration of intra-articular injection for reduction following anterior shoulder dislocation. You should now understand the anatomy of an evacuated glenoid fossa, mechanics of the intra-articular injection, and the advantages of using ultrasound for this procedure. As always, thanks for watching!
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Q1: Why is intra-articular injection used for shoulder dislocation reduction?
Intra-articular injection with local anesthetic like lidocaine provides significant pain relief during shoulder reduction. Reduction is the best form of analgesia and restores arm function, but the procedure itself is extremely painful. Injecting lidocaine into the joint space decreases pain perception and eliminates the need for complete sedation, reducing complications and emergency department resource requirements.
Q2: What are the main types of shoulder dislocations?
The three major types of shoulder dislocations are anterior, posterior, and inferior. Anterior shoulder dislocation is most common, accounting for approximately 95% of cases. Anterior dislocations are further classified into four subtypes: subcoracoid (75% of anterior cases), subglenoid (20%), subclavicular, and intrathoracic. The shoulder's extensive range of motion and considerable instability make dislocations one of the most common joint disarticulations in emergency settings.
Q3: How do you identify the injection site for intra-articular shoulder injection?
Palpate the posterior acromion and coracoid to locate the lateral sulcus, an abnormal depression in the skin caused by an empty glenoid fossa in anterior shoulder dislocation. Press into the shoulder from the posterolateral or lateral side; the sulcus will be evident by finger intrusion into the space. Mark this site with a skin marker as your insertion point for the injection.
Q4: What confirms successful needle placement in the joint capsule?
When the needle enters the injured joint capsule, serosanguinous fluid will be seen in the syringe upon aspiration. This blood-tinged fluid confirms accurate placement within the joint space. If no fluid is aspirated after full needle insertion, the needle may be too short or in an incorrect position. In such cases, a longer spinal needle or ultrasound guidance may be necessary.
Q5: How does ultrasound guidance improve the intra-articular injection procedure?
Ultrasound guidance allows real-time visualization of the needle tip reaching the appropriate joint space, enhancing procedure success. The linear probe suits thin patients while the curvilinear probe suits larger individuals. Under ultrasound, you can follow the needle in an in-plane approach, direct it toward the blood clot in the empty glenoid fossa, and visualize lidocaine as a swirling motion when injected, confirming correct placement.
Q6: What complications can occur during intra-articular shoulder injection?
Inadequate needle length is a primary complication, especially in obese or muscular patients where regular needles cannot pierce subcutaneous tissue; a longer 22-gauge spinal needle may be required. Inappropriate needle trajectory can cause the needle to abut against bony prominences, creating resistance. Ultrasound guidance helps determine the appropriate pathway and increases procedure success by avoiding these complications.
Q7: How long does intra-articular anesthesia take to become effective?
After injecting 10-20 mL of lidocaine into the joint space, wait 10-15 minutes to assess the anesthetic effect. Ask the patient if their pain has decreased to determine if adequate anesthesia has been achieved. Once sufficient pain relief is confirmed, proceed with shoulder reduction. Ultrasound can then confirm correct humeral head placement in line with the glenoid after reduction.