What is Quadrilateral Space Syndrome (QSS)?

Quadrilateral Space Syndrome (QSS) is a rare condition that occurs when the axillary nerve and/or the posterior circumflex humeral artery get squeezed or compressed as they pass through a small area in the back of your shoulder called the 'quadrilateral space.' This compression can lead to pain, numbness, tingling, and weakness in your arm.

QSS is often caused by repetitive overhead activities, common in athletes like throwers, swimmers, and tennis players. It can also result from repeated motions that narrow the space (overuse), extra bands of tissue that can form and compress the nerve or artery (fibrous bands), trauma or injury such as a shoulder dislocation or a direct blow to the shoulder which can cause swelling or scar tissue, or muscle enlargement if muscles in the area grow significantly (e.g., in bodybuilders), they can crowd the space.

What are the common symptoms of QSS?

Symptoms typically include vague pain or a dull ache in the back of the shoulder, sometimes radiating down the arm; numbness, tingling, or a 'pins and needles' sensation in the shoulder and upper arm; pain that worsens with overhead movements or when your arm is in a 'throwing' position; tenderness when pressure is applied over the back of the shoulder in the quadrilateral space; weakness or fatigue in the arm, especially when lifting or rotating it; and sometimes, shrinking (atrophy) of certain shoulder muscles like the teres minor or deltoid.

How is QSS diagnosed?

Diagnosing QSS can be challenging because its symptoms can be similar to other shoulder problems. Your doctor will ask about your symptoms, activities, and any past injuries; perform a physical examination to check your shoulder's range of motion, strength, sensation, and tenderness; may order imaging tests like MRI or ultrasound to look at the quadrilateral space, assess muscle size, and check for any abnormalities or scarring. In some cases, nerve conduction studies (NCS) or electromyography (EMG) might be performed to evaluate how well the axillary nerve is working. An injection of local anesthetic into the quadrilateral space that temporarily relieves your symptoms can also help confirm the diagnosis.

When is surgery considered for QSS?

Surgery is usually considered if non-surgical treatments haven't significantly improved your symptoms after about six weeks or more; symptoms are severe or progressively worsening; or there's clear evidence of nerve damage or significant compression.

What does the surgical procedure involve?

The goal of surgery, called decompression, is to relieve pressure on the axillary nerve and posterior circumflex humeral artery. This typically involves making a small incision at the back of your shoulder; identifying the compressed nerve and artery; carefully removing or cutting any fibrous bands, scar tissue, or other abnormal structures that are causing the compression. The procedure is designed to free up the nerve and artery, allowing them to function normally.

What are the potential risks of surgery?

As with any surgery, there are potential risks, though QSS surgery is generally safe. These can include infection, bleeding, damage to surrounding nerves or blood vessels, scarring, persistent pain or incomplete relief of symptoms, and reaction to anesthesia. Your surgeon will discuss these risks with you in detail.

What do I need to do before surgery?

Your healthcare team will provide specific instructions, but generally, you may need to undergo a pre-operative physical examination and blood tests; stop certain medications (e.g., blood thinners, some anti-inflammatory drugs) a week or two before surgery; arrange for someone to drive you home after surgery and help you during the first few days of recovery; and avoid eating or drinking for a certain period before the surgery.

What can I expect immediately after surgery?

You will likely have your arm in a sling to help it rest and heal. You may experience some pain, which will be managed with medication. Your surgical site will be covered with a dressing. Your surgeon will give you instructions on wound care and activity restrictions.

What is the expected long-term outcome?

For many patients, surgical decompression of QSS provides significant relief from pain, numbness, and weakness, allowing them to return to their normal activities, including sports. Nerve healing can be slow, so improvement may continue for several months. While some mild symptoms may occasionally linger, the goal is to significantly improve your quality of life and shoulder function.

Shoulder Conditions

AC Joint (Acromioclavicular Joint) Osteoarthritis

Get Clear, Concise Answers to Your Top Questions About AC Joint (Acromioclavicular Joint) Osteoarthritis

Navigating a shoulder condition can be overwhelming. On this page, we've compiled the 15 most frequently asked questions about AC Joint (Acromioclavicular Joint) Osteoarthritis to give you straightforward, expert-backed answers. Understand your symptoms, diagnosis, and what comes next with insights from Dr. Christian Veillette's practice. Plus, explore trusted external resources for even more information.

This article provides general information about AC Joint Osteoarthritis to help you understand your condition and treatment options.

Q1: What is AC Joint Osteoarthritis?

The AC (Acromioclavicular) joint is located at the top of your shoulder, where your collarbone (clavicle) meets a part of your shoulder blade (acromion). Osteoarthritis in this joint means the smooth cartilage cushioning the ends of these bones has worn down. This can cause pain and difficulty with shoulder movement.

Q2: What causes AC Joint Osteoarthritis?

AC joint osteoarthritis is often due to normal wear and tear over time, especially in people over 40. It can also develop after a past injury to the AC joint, like a shoulder separation, or from repeated stress on the joint from activities like heavy lifting or overhead work.

Q3: What are the common symptoms of AC Joint Osteoarthritis?

Common symptoms include pain and tenderness directly over the top of the shoulder, often worse when you bring your arm across your chest, reach overhead, or lift heavy objects. The pain might spread to your upper arm, neck, or chest. You might also notice a clicking or snapping sensation, or a bump over the joint.

Q4: How is AC Joint Osteoarthritis diagnosed?

Your doctor will ask about your symptoms and medical history. They will perform a physical exam, moving your arm in different ways to check your shoulder's movement and pain. X-rays are typically used to show narrowing of the joint space or bone spurs, which are signs of osteoarthritis. Sometimes, an injection of a local anesthetic into the AC joint can help confirm the diagnosis.

Q5: What are the non-surgical treatment options?

Most people with AC joint osteoarthritis do not need surgery. Non-surgical treatments often include:

Rest and Activity Modification: Avoiding activities that worsen your pain.
Pain Relief Medications: Over-the-counter anti-inflammatory drugs like ibuprofen or naproxen, or prescription medications.
Ice and Heat: Applying ice packs to reduce swelling and pain, or heat to relax muscles.
Physical Therapy: Exercises to improve your shoulder's range of motion, strength, and stability.
Corticosteroid Injections: A strong anti-inflammatory medication injected directly into the joint to reduce pain and swelling, often providing temporary relief.

Q6: What does surgery for AC Joint Osteoarthritis involve?

If non-surgical treatments don't provide enough relief, surgery might be considered. The most common surgery is called a "distal clavicle excision" or "Mumford procedure." In this procedure, a small portion (about 0.5 to 1 cm) of the end of the collarbone is removed. This creates space between the collarbone and the acromion, reducing friction and pain. This can be done through an open incision or with a small camera (arthroscopically).

Q7: What are the goals of AC Joint surgery?

The main goals of surgery are to relieve your pain, improve your shoulder's function, and allow you to return to your normal activities with less discomfort.

Q8: What are the potential risks of AC Joint surgery?

As with any surgery, there are risks, including:

Infection
Bleeding
Nerve damage
Stiffness
Continued pain or limited improvement in symptoms

Q9: What do I need to do to prepare for surgery?

Your doctor will provide specific instructions. Generally, you may need to:

Stop certain medications (like blood thinners) before surgery.
Arrange for someone to drive you home and help you for the first few days after surgery.
Follow any fasting instructions given by your surgical team.

Q10: What can I expect immediately after AC Joint surgery?

You may experience pain and swelling, which will be managed with medication. You might be in a sling for a short period, though some surgeons may not require one. Early, gentle movement and physical therapy usually begin soon after surgery.

Q11: How long is the typical recovery period?

Recovery varies for each person. Most people begin to feel better within a few weeks. Full recovery, especially for more strenuous activities, can take anywhere from 3 to 4 months. Physical therapy is a crucial part of this recovery.

Q12: What does rehabilitation/physical therapy involve?

Physical therapy will guide you through exercises to:

Restore your shoulder's range of motion.
Strengthen the muscles around your shoulder.
Improve your posture and scapular (shoulder blade) control.
Gradually return you to your daily and recreational activities.

Q13: How will pain be managed during recovery?

Your doctor will prescribe pain medication as needed. You can also use ice packs to help reduce pain and swelling. Following your physical therapy exercises as directed can also help manage discomfort by improving your shoulder's function.

Q14: What self-care can I do at home to help my recovery?

Follow medication instructions: Take pain relievers and anti-inflammatory medications as prescribed.
Apply ice: Use ice packs to the shoulder for 15-20 minutes at a time, several times a day, especially after exercise.
Rest: Avoid activities that cause pain, especially during the early stages of recovery.
Gentle movement: Perform exercises as instructed by your physical therapist.
Maintain a healthy lifestyle: A balanced diet and good sleep can support your body's healing process.

Q15: When can I expect to return to daily activities, work, driving, and sports?

This depends on your individual healing and the demands of your activities.

Daily Activities: You may be able to perform light daily activities within a few days to a couple of weeks.
Driving: Often possible when you can comfortably and safely control the steering wheel and have adequate reaction time, typically a few weeks after surgery.
Work: Desk jobs might be possible within a few weeks. More physically demanding jobs could require 3 months or longer.
Sports/Heavy Lifting: Return to sports or activities involving overhead lifting or heavy use of the shoulder can take 3 months or more, depending on the sport and your progress in physical therapy. Always follow your doctor's and therapist's advice.

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We encourage you to write down any specific questions you have and discuss them thoroughly with your surgeon, doctor, or physical therapist.

Disclaimer: This brochure provides general information and is not a substitute for professional medical advice. Always consult your doctor or qualified healthcare provider with any questions you may have regarding your specific medical condition and treatment plan.

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