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.

Post-Operative Protocols

Arthroscopic SLAP Repair Protocol

Phase-by-phase post-operative rehabilitation protocol for Arthroscopic SLAP Repair to guide recovery and physical therapy.

A structured rehabilitation plan is essential for optimal recovery after surgery. On this page, we outline the phase-based protocol for Arthroscopic SLAP Repair to guide you and your physical therapist through a safe recovery.

An arthroscopic Superior Labrum Anterior to Posterior (SLAP) repair is a surgical procedure performed to reattach a torn superior labrum to the glenoid, restoring stability to the shoulder joint and anchoring the long head of the biceps tendon. Because the biceps tendon inserts directly onto the repaired labrum, rehabilitation must carefully protect the repair from excessive biceps tension and traction forces during the early phases of healing. This protocol outlines a structured, phase-based rehabilitation pathway designed to optimize recovery, restore range of motion, and rebuild strength while ensuring the long-term integrity of the repair.

Phase 1: Protection and Early ROM (Weeks 0-6)

The primary focus of this phase is to protect the anatomical repair, minimize pain and inflammation, and initiate gentle passive range of motion (PROM) within safe limits. Protecting the biceps anchor from tension is critical during this period.

Goals: Protect the healing superior labrum and biceps anchor; Minimize pain and inflammatory response; Gradually restore passive range of motion within safe boundaries; Maintain wrist, hand, and elbow mobility (without resistance).
Precautions & Restrictions: Sling must be worn at all times (including during sleep) for the first 4 weeks, and can be discontinued at week 6; No active biceps contraction (no resisted elbow flexion or forearm supination); No active shoulder range of motion (AROM); Limit passive forward flexion to 90 degrees (weeks 0-4) and progress to 120 degrees (weeks 5-6); Limit passive external rotation (ER) in scaption to 30 degrees (weeks 0-4) and progress to 45 degrees (weeks 5-6); Avoid shoulder extension, horizontal abduction, and cross-body adduction.
Suggested Exercises: Pendulum exercises; Passive forward flexion in the scapular plane (limitations: 90 degrees until week 4, then 120 degrees); Passive external rotation in scaption (limitations: 30 degrees until week 4, then 45 degrees); Active elbow, wrist, and hand exercises (without weight or resistance); Scapular squeezes and submaximal shrugs.
Criteria to Progress: At least 6 weeks post-surgery; Minimal pain and inflammation; Passive forward flexion to 120 degrees; Passive external rotation to 45 degrees in scaption.

Phase 2: Intermediate Active Motion & Early Strengthening (Weeks 6-12)

The goal of this phase is to gradually discontinue the sling, restore full passive and active range of motion, and begin light, non-resisted biceps activation and submaximal rotator cuff and scapular strengthening.

Goals: Discontinue sling use; Restore full active-assisted and active range of motion (AAROM/AROM); Re-establish normal scapulohumeral dynamics; Initiate light rotator cuff and scapular strengthening (isometric and light isotonic).
Precautions & Restrictions: No resisted biceps loading (no resisted elbow flexion or supination) until week 10-12; Avoid sudden jerking motions; No overhead lifting or heavy carrying; Avoid end-range aggressive stretching of the anterior capsule.
Suggested Exercises: Active-assisted and active range of motion (AAROM/AROM) in flexion and scaption; Progress passive range of motion to full in all directions (aiming for full ER by week 10-12); Internal rotation stretching (sleeper stretch); Scapular stabilization exercises (rows, shrugs, and scapular retraction); Submaximal rotator cuff isometrics (ER, IR, abduction); Light resistance band external and internal rotation (with elbow at side, avoiding biceps recruitment).
Criteria to Progress: Full, pain-free active range of motion (except for end-range external rotation at 90 degrees abduction); Good scapulohumeral rhythm during shoulder elevation; Rotator cuff strength rated at least 4/5; Minimal to no pain with basic activities of daily living.

Phase 3: Progressive Strengthening (Weeks 12-16)

This phase focuses on restoring full strength, power, and endurance of the rotator cuff and scapular stabilizers, and introducing progressive resisted biceps strengthening.

Goals: Restore full, pain-free range of motion in all planes; Normalize strength and endurance of the rotator cuff and scapular muscles; Safely initiate progressive biceps loading; Improve dynamic glenohumeral stability.
Precautions & Restrictions: Avoid sudden, high-impact forces; Avoid heavy overhead lifting; Maintain correct scapulohumeral rhythm during resisted movements; Discontinue any exercise that reproduces mechanical clicking or pain.
Suggested Exercises: Resisted external and internal rotation at 90 degrees of abduction; Progressive scapular strengthening (t-bar exercises, prone horizontal abduction); Light, resisted elbow flexion and supination (biceps loading) starting with 1-2 pounds and progressing slowly; Closed-chain stabilization exercises (e.g., wall slides, quadruped weight-shifts); Dynamic stabilization drills (rhythmic stabilization at 90 degrees flexion).
Criteria to Progress: Full pain-free active ROM in all planes; Scapular control and rotator cuff strength at least 80% of the uninvolved side; No pain or clicking with progressive biceps loading.

Phase 4: Return to Sport and Unrestricted Activity (Weeks 16-24+)

Rehabilitation in this final phase focuses on higher-velocity movements, advanced dynamic stabilization, sport- or work-specific training, and a graduated return to full activity.

Goals: Maximize muscular strength, power, and endurance; Restore neuromuscular control during high-velocity movements; Safely return to sports, recreation, or heavy manual labor; Implement a long-term home maintenance conditioning program.
Precautions & Restrictions: Gradual return to sports or heavy manual work (avoiding abrupt spikes in activity); Modify activities if pain or instability occurs; Maintain proper recovery protocols between training sessions.
Suggested Exercises: Advanced rotator cuff and periscapular strengthening; Plyometric training (two-handed chest passes, overhead medicine ball throws, and wall rebounds); Sport-specific drills (interval throwing program, swimming mechanics, or overhead racket training); Gym-based exercise progression (bench press, overhead press, pull-downs) with proper form and gradual loading; Continued long-term home stretching and strengthening program.
Criteria to Progress (Full Activity Release): Full, pain-free active range of motion; Rotator cuff and scapular strength equal to 90% or more of the uninvolved side; Completion of sport-specific progression without pain or symptoms; Surgeon clearance.

These guidelines represent a standard rehabilitation protocol. Individual recovery rates vary significantly depending on the size of the repair, bone/tissue quality, and general patient health. Your surgeon may modify this protocol specifically for you.

Disclaimer: This protocol is for educational purposes and is not a substitute for professional medical advice. Always consult your surgeon or physical therapist before performing any exercises or modifying activity restrictions.

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Proximal Humerus ORIF Protocol

Phase-by-phase post-operative rehabilitation protocol for Proximal Humerus ORIF (Open Reduction Internal Fixation) to guide recovery and physical therapy.