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.

What are the non-surgical treatment options?

Most cases of QSS improve with non-surgical treatment. These options focus on reducing pressure on the nerve and artery, managing pain, and restoring function: rest and activity modification (avoiding or modifying activities that worsen your symptoms, especially overhead movements); anti-inflammatory medications (over-the-counter or prescription NSAIDs like ibuprofen can help reduce pain and inflammation); ice or heat packs (applying ice can help reduce pain and inflammation, especially after activity, heat can help relax muscles); physical therapy (a physical therapist will guide you through exercises to maintain or improve shoulder range of motion and flexibility, strengthen the muscles around your shoulder to provide better support, improve posture and body mechanics); and corticosteroid injections (in some cases, your doctor may suggest an injection of corticosteroid medication into the area to reduce inflammation and pain).

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.

How long is the typical recovery period?

Recovery times vary for each person, depending on the severity of the condition and how long the nerve was compressed. First few weeks (0-2 weeks): Focus on rest, pain management, and protecting the surgical site. Gentle elbow and wrist movements will be encouraged. Weeks 2-6: You will start physical therapy, focusing on gentle range-of-motion exercises for your shoulder. After 6 weeks: As healing progresses, your physical therapist will introduce strengthening exercises to rebuild muscle strength. Overall, it can take several weeks to months to feel significant improvement, as nerve healing is a slow process.

What does rehabilitation/physical therapy involve?

Physical therapy is crucial for a successful recovery. Your therapist will design a personalized program that may include pain and swelling management (using ice, gentle massage, or other techniques); range of motion exercises (to restore full movement in your shoulder); strengthening exercises (targeting the muscles around your shoulder, including the deltoid and teres minor, which may have been weakened); postural correction (to improve overall shoulder mechanics); and activity-specific training (gradually reintroducing movements related to your work, sports, or daily activities).

How will pain be managed?

Your doctor will prescribe pain medication to help manage discomfort after surgery. This may include prescription pain relievers (e.g., opioids for a short period); over-the-counter pain relievers (e.g., acetaminophen, ibuprofen) as recommended by your doctor. You may also use ice packs to reduce localized pain and swelling.

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

This timeline varies greatly based on your recovery progress and the demands of your activities. Daily activities: Light daily activities can usually be resumed within a few days to weeks. Driving: You can typically drive once you are no longer taking strong pain medications and have sufficient control and range of motion in your shoulder to safely operate a vehicle (often a few weeks after surgery). Work: Return to work depends on the nature of your job. Light, desk-based work might be possible within a few weeks, while jobs requiring heavy lifting or repetitive overhead movements will take longer, potentially several months. Sports: A gradual return to sports, especially overhead activities, will be guided by your physical therapist and surgeon, often not for several months after surgery. Full return to competitive sports may take 3-6 months or longer.

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.

Surgical Shoulder Procedures

Arthroscopic Subacromial Decompression/Bursectomy

Get Clear, Concise Answers to Your Top Questions About Arthroscopic Subacromial Decompression and Bursectomy

Learn about arthroscopic subacromial decompression and bursectomy, a keyhole shoulder surgery to relieve impingement and pain by removing the bursa and bone spurs.

Q1. What is arthroscopic subacromial decompression and bursectomy?

This is a minimally invasive keyhole shoulder surgery. It removes a swollen fluid-filled sac (bursa) and shaves down any bone spurs that are squeezing or rubbing against your rotator cuff tendons. The goal is to create more space in your shoulder joint so your arm can move freely without pain.

Q2. Why is this procedure performed?

It is performed to treat painful shoulder impingement syndrome, which happens when the bones in your shoulder pinch the tendons or bursa during movement. It is recommended after non-surgical treatments like rest, physical therapy, and cortisone injections have failed to provide relief.

Q3. What is subacromial impingement and how does it relate to the bursa?

In a healthy shoulder, the bursa acts as a lubricating cushion between the rotator cuff tendons and the top bone of the shoulder (acromion). In impingement, this space becomes too narrow. This causes:

The bursa to become inflamed, swollen, and painful (bursitis).
The tendons to rub against the bone, leading to fraying or tears (tendonitis).
Persistent pain, especially when reaching overhead or behind your back.

Q4. How is the surgery performed?

The surgeon makes two or three tiny incisions (about the size of a keyhole) around your shoulder. A tiny camera called an arthroscope is inserted to see inside the joint. The surgeon then uses small instruments to:

Clear away the inflamed bursa tissue (bursectomy).
Shave off any bone spurs on the underside of the acromion bone (subacromial decompression or acromioplasty).
Inspect the rotator cuff tendons for any signs of damage.

Q5. What type of anesthesia is used during the procedure?

Most patients receive a combination of general anesthesia (which puts you to sleep) and a regional nerve block. The nerve block numbs your shoulder and arm, providing excellent pain relief for 12 to 24 hours after the surgery.

Q6. How long does the surgery take and is a hospital stay required?

The procedure typically takes between 30 and 60 minutes. It is performed as an outpatient day surgery, meaning you can return home the same day once you have recovered from the anesthesia.

Q7. What are the main risks associated with this surgery?

While this surgery is highly safe, all procedures carry some risks. These include:

Infection at the incision sites or deep in the joint.
Shoulder stiffness (frozen shoulder) if early movement is not maintained.
Temporary or persistent numbness from the nerve block or swelling.
Continued pain if there is other undiagnosed damage in the shoulder.

Q8. What should I do to prepare for the surgery?

Preparing properly helps ensure a smooth experience. You should:

Avoid eating or drinking anything after midnight before your surgery.
Arrange for a family member or friend to drive you home and stay with you for the first 24 hours.
Set up a comfortable sleeping space, as sleeping flat may be difficult initially.
Wear loose-fitting, button-up clothing that is easy to put on over a bulky shoulder dressing.

Q9. Will I need to wear a sling after the surgery, and for how long?

Yes, you will wear a sling immediately after surgery for comfort and protection. However, unlike a rotator cuff repair, you are encouraged to remove the sling for gentle exercises and daily activities as tolerated. Most patients stop using the sling within 1 to 2 weeks.

Q10. How should I manage pain and swelling after returning home?

You can manage discomfort using these strategies:

Take your prescribed pain medications on a regular schedule for the first few days.
Apply ice packs to your shoulder for 20 minutes at a time, several times a day.
Keep your incisions clean and dry, following your surgeon's instructions for dressing changes.
Avoid heavy lifting, pushing, or pulling with the surgical arm.

Q11. What is the best position for sleeping after the procedure?

Many patients find sleeping in a recliner chair or propped up with several pillows in bed to be the most comfortable position. Keeping your torso slightly upright reduces the pressure on your shoulder joint and helps minimize throbbing pain at night.

Q12. When can I start physical therapy, and what does it involve?

Gentle motion exercises usually start within the first few days after surgery. Formal physical therapy often begins within 1 to 2 weeks. It focuses on:

Restoring full range of motion with passive and active stretches.
Strengthening the rotator cuff and shoulder blade muscles.
Improving shoulder mechanics to prevent future impingement.

Q13. How long is the overall recovery time, and when can I return to work or sports?

Recovery timelines vary by individual, but general guidelines are:

Desk jobs: 1 to 2 weeks.
Light duty or repetitive lifting jobs: 4 to 6 weeks.
Heavy manual labor: 2 to 3 months.
Recreational sports and full recovery: 3 to 6 months.

Q14. What warning signs should I watch out for during recovery?

Contact your surgical team immediately if you experience any of the following:

Fever above 101°F (38.3°C) or chills.
Increased redness, warmth, or drainage from the incisions.
Severe pain that is not relieved by your medications.
Shortness of breath or chest pain.
Sudden swelling or pain in your calf.

Q15. How successful is this surgery in relieving shoulder pain?

The procedure has a very high success rate, with about 85% to 90% of patients experiencing significant pain relief and improved shoulder function. Dedication to your physical therapy program is a key factor in achieving the best possible outcome.

We encourage you to write down any specific questions you have and discuss them thoroughly with your surgeon, doctor, or physical therapist. They are your best resource for personalized advice and care.

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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