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

Total Shoulder Arthroplasty - Anatomic

Get Clear, Concise Answers to Your Top Questions About Total Shoulder Arthroplasty - Anatomic

If you are scheduled for or considering an anatomic total shoulder replacement, understanding the procedure and recovery is key to a successful outcome. This guide answers the top 15 patient questions about anatomic shoulder arthroplasty.

Q1. What is anatomic total shoulder arthroplasty?

Anatomic total shoulder arthroplasty is a surgical procedure that replaces a damaged shoulder joint with artificial parts designed to mimic your natural anatomy. In a healthy shoulder, the round ball of your upper arm bone (humerus) fits into a shallow socket (glenoid). During this surgery, the worn-out ball is replaced with a highly polished metal ball, and the damaged socket is lined with a smooth plastic cup. This helps eliminate bone-on-bone friction, relieves pain, and restores mobility.

Q2. How does anatomic shoulder replacement differ from reverse shoulder replacement?

An anatomic shoulder replacement keeps the natural ball-and-socket design of your joint, placing the artificial ball on your arm bone and the socket on your shoulder blade. This procedure relies on a healthy, intact rotator cuff (the group of muscles and tendons surrounding the joint) to move the arm. In contrast, a reverse shoulder replacement switches the position of the ball and socket, placing the ball on the shoulder blade and the socket on the arm bone. A reverse replacement is used when the rotator cuff is severely damaged or non-functional, relying on the larger deltoid muscle to move the arm instead.

Q3. Who is a good candidate for an anatomic total shoulder arthroplasty?

You may be a good candidate for this procedure if you experience:

Severe, chronic shoulder pain that interferes with daily tasks like reaching, dressing, and sleeping.
Advanced arthritis or joint damage confirmed by X-rays or MRI.
Pain that has not improved with conservative treatments like physical therapy, medications, or injections.
An intact and functional rotator cuff, which is required to support and move the anatomic replacement.

Q4. What causes the need for anatomic total shoulder replacement?

The most common cause is the gradual wearing down of the joint cartilage, which can result from:

Osteoarthritis: General wear and tear that comes with aging.
Rheumatoid arthritis: An autoimmune condition that causes chronic joint inflammation.
Post-traumatic arthritis: Joint damage following a severe shoulder fracture or injury.
Avascular necrosis: A condition where the bone tissue dies due to a temporary loss of blood supply to the ball of the shoulder.

Q5. How is the surgery performed?

The surgeon makes an incision along the front of your shoulder. The muscles are gently parted to access the joint. The surgeon removes the damaged surface of the ball at the top of your upper arm bone and inserts a metal stem with a metal ball. The damaged surface of the socket is then smoothed down, and a plastic socket component is cemented in place. The muscles and skin are then carefully closed with sutures or staples, and a sterile dressing is applied.

Q6. What kind of anesthesia is used during the procedure?

Most patients receive a combination of general anesthesia and a regional nerve block. General anesthesia keeps you completely asleep and pain-free during the operation. The regional nerve block involves injecting numbing medication around the nerves that lead to your shoulder. This block provides excellent pain control for 12 to 24 hours after the surgery, reducing the need for strong pain medications immediately after you wake up.

Q7. How long does the surgery take, and how long will I stay in the hospital?

The surgery itself typically takes about 1 to 2 hours. After surgery, you will spend another 1 to 2 hours in the recovery room. Most patients stay in the hospital for one night, though some patients are able to go home the same day (outpatient surgery) if they meet specific safety criteria and have adequate support at home.

Q8. What should I expect immediately after surgery in the recovery room?

When you wake up, your arm will be resting in a protective sling. Your shoulder will feel numb from the nerve block, and you may have an intravenous (IV) line in your arm to deliver fluids and pain medications. The medical team will closely monitor your vital signs, check your pain levels, and help you transition to drinking and eating light foods when you feel ready.

Q9. How long do I need to wear a sling after surgery?

You will need to wear a protective sling for approximately 4 to 6 weeks. The sling keeps your shoulder in a stable position while the surrounding muscles and tissues heal. You should wear it at all times, including when sleeping and walking. You may remove the sling only for showering and performing gentle elbow, wrist, and hand exercises as directed by your surgeon.

Q10. What is the typical recovery timeline?

Recovery is a gradual process that varies for each individual, but a general timeline includes:

Weeks 1 to 6: Wearing the sling, performing gentle range-of-motion exercises, and managing discomfort.
Weeks 6 to 12: Transitioning out of the sling, starting active movements, and beginning light daily activities.
Months 3 to 6: Introducing strengthening exercises and returning to most normal activities.
Months 6 to 12: Achieving full recovery, with continued improvements in strength, flexibility, and comfort.

Q11. When can I start physical therapy, and what does it involve?

Physical therapy starts very soon after surgery, often within the first few days or week. Initially, therapy focuses on passive exercises, where the therapist or your other arm moves your surgical arm to prevent stiffness without straining the healing tissues. Around 6 weeks, you will transition to active exercises where you move the arm using its own muscles. Gradually, strengthening exercises are added to help you regain full function of your shoulder.

Q12. What are the common risks or potential complications of this surgery?

While anatomic shoulder replacement is highly successful, risks are present with any surgery. These can include:

Infection at the surgical site or deep within the joint.
Blood clots forming in the arm or legs.
Nerve damage causing temporary or permanent numbness or weakness.
Stiffness or failure of the joint to regain expected movement.
Loosening or wear of the artificial parts over time.

Q13. How should I prepare my home for recovery?

Preparing your home beforehand can make your recovery much easier and safer. Consider these steps:

Arrange for help: Have someone stay with you or help with meals, grocery shopping, and driving for the first couple of weeks.
Set up a recovery station: Keep items like your phone, tablet, medications, TV remote, and water bottle within easy reach.
Place clothes conveniently: Choose loose-fitting shirts that button up or zip in the front, and slip-on shoes.
Prevent falls: Remove loose rugs, secure electrical cords, and make sure paths are clear and well-lit.
Prepare meals: Cook and freeze meals in advance so they are easy to reheat.

Q14. What are the long-term activity restrictions after an anatomic shoulder replacement?

To protect your new joint and help it last as long as possible, you should avoid:

Repetitive heavy lifting (usually restricted to 20 to 25 pounds permanently).
High-impact activities like chopping wood, jackhammering, or contact sports.
Sports that place extreme stress on the joint, such as weightlifting or forceful overhead throwing.
Safe activities include swimming, golf, tennis (often with modifications), cycling, and gardening.

Q15. What is the lifespan of an anatomic shoulder replacement?

Modern anatomic shoulder replacements are highly durable. Studies show that about 85% to 90% of anatomic shoulder replacements continue to function well for 15 years or more. Following your recovery plan, staying active with low-impact exercises, and avoiding heavy lifting will help prolong the life of your artificial joint.

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.

Browse all articles