Stimson Technique: Understanding Shoulder Dislocation Reduction, Procedure, and Safety

What is Stimson technique?

The Stimson technique is a specific, non-surgical method utilized by trained medical professionals to reduce an acute anterior shoulder dislocation, primarily employing gravity and gentle traction to guide the humeral head back into the glenoid fossa.

Introduction to the Stimson Technique

The Stimson technique, named after American surgeon Dr. Lewis Stimson, is a well-established and widely used closed reduction method for anterior glenohumeral (shoulder) dislocations. Unlike more forceful maneuvers, the Stimson technique leverages the principle of muscle relaxation through sustained, low-force traction, often aided by gravity, to gently coax the dislocated humeral head back into its anatomical position within the shoulder socket. This approach prioritizes patient comfort and minimizes the risk of iatrogenic injury, making it a preferred method in many clinical settings.

Understanding Shoulder Anatomy and Dislocation

To appreciate the Stimson technique, a brief understanding of shoulder anatomy is crucial. The shoulder joint, or glenohumeral joint, is a ball-and-socket joint formed by the head of the humerus (upper arm bone) and the glenoid fossa (a shallow socket on the scapula, or shoulder blade). It is the most mobile joint in the human body, allowing for a wide range of motion. However, this mobility comes at the expense of stability, making it highly susceptible to dislocation.

• Anterior Dislocation: The vast majority (over 95%) of shoulder dislocations are anterior, meaning the humeral head displaces forward and typically inferiorly relative to the glenoid fossa. This often occurs due to a fall on an outstretched arm or a direct blow to the shoulder when the arm is abducted and externally rotated.
• Muscle Spasm: Following a dislocation, the powerful muscles surrounding the shoulder (e.g., deltoid, rotator cuff) often go into protective spasm, making reduction challenging. The Stimson technique aims to overcome this spasm through prolonged, gentle distraction.

How the Stimson Technique Works

The core mechanism of the Stimson technique relies on:

• Gravity-Assisted Traction: The patient lies prone (face down) with the dislocated arm hanging freely off the edge of the examination table. This position allows gravity to exert continuous, gentle downward traction on the humerus.
• Weight Application: A small amount of weight (typically 5-10 pounds or 2.5-4.5 kg) is often attached to the wrist or forearm of the affected arm. This added weight augments the gravitational pull, providing consistent, low-level force.
• Muscle Relaxation: The sustained traction, combined with the prone position, encourages the shoulder muscles to relax over time. As the muscles relax, the humeral head is less resisted and can more easily be guided back into the glenoid fossa.
• Gentle Manipulation (Optional): Once sufficient muscle relaxation is achieved (which can take 10-20 minutes or more), the clinician may apply very gentle, oscillating movements, or slight internal/external rotation to facilitate the final reduction.

Indications and Contraindications

The Stimson technique is a safe and effective option under specific circumstances.

Indications:

• Acute Anterior Glenohumeral Dislocation: It is primarily used for recent, uncomplicated anterior dislocations.
• Absence of Fracture: Crucially, there must be no suspected fracture of the humeral head, glenoid, or surgical neck of the humerus.

Contraindications:

• Suspected Fracture: Any suspicion of an associated fracture (e.g., greater tuberosity fracture, Hill-Sachs lesion, Bankart lesion with significant bone involvement) is a contraindication, as manipulation could worsen the fracture. X-rays are mandatory before attempting reduction.
• Neurovascular Compromise: Signs of nerve damage (numbness, tingling, weakness) or vascular compromise (absent pulse, pallor) require immediate advanced medical intervention and may contraindicate this or any closed reduction technique until the neurovascular status is stabilized.
• Posterior or Inferior Dislocations: The Stimson technique is specifically designed for anterior dislocations and is not appropriate for other types.
• Recurrent Dislocations: While not an absolute contraindication, frequent dislocations may indicate underlying instability requiring surgical consultation.

Step-by-Step Procedure (For Trained Medical Professionals)

It is critical to reiterate that the Stimson technique must only be performed by trained medical professionals after a thorough assessment, including imaging.

1. Pre-Reduction Assessment:

   • Obtain X-rays to confirm dislocation type and rule out fractures.
   • Perform a thorough neurovascular examination of the affected arm (pulse, sensation, motor function) and document findings.
   • Administer appropriate pain medication and/or conscious sedation as needed to facilitate muscle relaxation and patient comfort.

2. Patient Positioning:

   • Position the patient prone (face down) on an examination table.
   • The affected arm should hang freely off the side of the table, perpendicular to the floor. Ensure the arm is not resting on anything.

3. Weight Application:

   • Attach a weight (typically 5-10 lbs or 2.5-4.5 kg) to the wrist or forearm of the affected arm. This can be done using a stockinette or bandage wrap to distribute the weight evenly.

4. Wait for Muscle Relaxation:

   • Allow the weight and gravity to exert continuous traction for 10-20 minutes, or longer if necessary. Encourage the patient to relax and breathe deeply. Muscle relaxation is key to success.

5. Gentle Manipulation (If Needed):

   • Once sufficient muscle relaxation is evident, the clinician may apply very gentle, slow internal or external rotation of the arm, or slight adduction, to assist the humeral head in relocating. A palpable "clunk" or visible reduction often indicates success.

6. Post-Reduction Assessment:

   • Immediately after suspected reduction, repeat the neurovascular examination to ensure no new deficits.
   • Obtain post-reduction X-rays to confirm successful reduction and rule out iatrogenic fractures or other complications.
   • Immobilize the shoulder, typically in a sling or shoulder immobilizer, for a period determined by the physician, followed by a structured rehabilitation program.

Advantages and Disadvantages

Advantages:

• Non-Invasive: It does not involve incisions or forceful manipulation.
• Reduced Need for Sedation: Often requires less or no deep sedation compared to more forceful techniques, making it safer for certain patients.
• Gentle and Low Force: Minimizes the risk of iatrogenic injury to soft tissues, nerves, or blood vessels.
• High Success Rate: When performed correctly with adequate muscle relaxation, it has a high success rate for anterior dislocations.
• Patient Comfort: Generally well-tolerated by patients due to the minimal force involved.

Disadvantages:

• Time-Consuming: Can take 10-20 minutes or more for adequate muscle relaxation, which may not be ideal in emergency situations requiring rapid reduction.
• Patient Positioning: The prone position may be challenging or impossible for some patients (e.g., those with spinal injuries, severe pain, or certain medical conditions).
• Requires Patient Cooperation: The patient needs to be able to lie prone and relax their muscles.
• Not Universal: Not suitable for all types of dislocations or in the presence of fractures.

Important Considerations and Safety

• Professional Expertise: The Stimson technique, like all reduction maneuvers, should only be performed by qualified medical professionals (physicians, physician assistants, nurse practitioners, paramedics) who are trained in musculoskeletal assessment and reduction techniques.
• Pre- and Post-Reduction Imaging: X-rays are crucial before and after any reduction attempt to confirm the type of dislocation, rule out fractures, and verify successful reduction.
• Neurovascular Status: Meticulous assessment of neurovascular status (pulses, sensation, motor function) before and after reduction is paramount to detect and manage potential complications.
• Pain Management: Adequate pain control and/or sedation are vital for patient comfort and to facilitate muscle relaxation, which is key to a successful, atraumatic reduction.
• Avoid Force: The principle of the Stimson technique is gentle, sustained traction. Forceful manipulation must be avoided, as it can cause further injury to nerves, vessels, or bone.

Conclusion

The Stimson technique stands as a testament to the power of understanding biomechanics and physiology in medical intervention. By harnessing gravity and promoting muscle relaxation through sustained, gentle traction, it offers an effective and relatively safe method for reducing acute anterior shoulder dislocations. While it is a valuable tool in the armamentarium of healthcare providers, its successful and safe application hinges on accurate diagnosis, meticulous execution by trained professionals, and careful pre- and post-reduction assessment to ensure optimal patient outcomes and prevent complications. If you suspect a shoulder dislocation, seek immediate medical attention; self-attempted reduction can lead to severe and irreversible damage.