Shoulder Impingement Syndrome: Symptoms, Causes and Treatment

Shoulder impingement syndrome is a clinical condition characterized by compression of the rotator cuff tendons and subacromial structures during arm elevation, leading to pain, limited motion, and functional impairment. It commonly develops due to repetitive overhead activity or anatomical narrowing.

Subacromial impingement symptoms typically include anterior or lateral shoulder pain, especially during lifting or reaching movements, along with night discomfort and reduced range of motion. Chronic cases may result in tendon degeneration, bursitis, and progressive weakness if untreated.

Rotator cuff impingement causes involve structural abnormalities such as acromial shape variations, tendon inflammation, and muscular imbalance. Repetitive strain and poor biomechanics contribute significantly, increasing friction within the subacromial space and exacerbating tissue irritation.

Shoulder impingement treatment approaches focus on conservative management, including physical therapy, anti-inflammatory medications, and activity modification. In resistant cases, corticosteroid injections or surgical decompression may be considered to restore normal biomechanics and alleviate symptoms.

What Are the Symptoms of Shoulder Impingement Syndrome?

Although the way the disease manifests can vary from person to person, we observe a common pattern of complaints among patients visiting our clinic. Typically, the pain begins insidiously; initially, it is felt only when lifting something heavy or performing an awkward movement, but over time it develops into a shoulder that aches even at rest. Patients often describe it as “It feels like there’s a knife inside my shoulder, and when I raise my arm, it stabs.”

The most characteristic feature of this syndrome is that the pain is triggered by specific movements. Movements involving raising the arm above head level are when impingement is most severe. It is also common for the pain to radiate from the shoulder down the side of the arm. Sometimes, this radiation reaches the elbow, leading patients to believe the problem is in the arm, whereas the actual issue lies within the shoulder joint.

One of the most debilitating symptoms is nighttime pain. The pain that is somewhat forgotten during the day becomes severe enough to wake the person up when lying down at night, especially when lying on the affected shoulder. This disrupts sleep quality, reduces daytime energy, and causes psychological strain.

Common complaints in shoulder impingement syndrome include:

• Pain during overhead activities
• Aching that wakes one from sleep at night
• Pain radiating to the side of the arm
• Restricted shoulder movement
• Difficulty when dressing or undressing
• Stabbing sensation when reaching for back pocket
• Shoulder weakness
• Clicking or friction sound in the shoulder

What Causes Shoulder Impingement Syndrome and What Are the Risk Factors?

This condition does not have a single cause; it generally arises from a combination of structural features and lifestyle. The shape of the “acromion” bone, which forms the roof of the shoulder joint, is one of the most important congenital risk factors. In some people, this bone is flat and provides ample space for tendons. However, in others, the tip of the bone is hooked or slopes downward. This hook-like structure, called “Type 3 Acromion,” constantly irritates the tendons passing underneath and predisposes them to impingement.

The aging process is also a natural risk factor. As we age, fluids inside the joint decrease, tendon flexibility is lost, and bony protrusions (osteophytes) associated with calcification develop. These further narrow the already tight tunnel, limiting the tendons’ movement space. However, it’s not limited to the elderly; we also frequently encounter it in younger and active individuals due to overuse.

Occupational strain and sports activities play a major role in the development of shoulder impingement syndrome. In people who work with their arms raised constantly, the load on the shoulder joint is much higher than normal. Similarly, repetitive microtraumas in sports that heavily involve shoulder use can lead to edema and impingement over time.

Groups at risk include:

• Painters and decorators
• Teachers
• Volleyball players
• Swimmers
• Tennis players
• Warehouse workers
• Cleaning staff
• Carpenters
• Weightlifters

How Is Shoulder Impingement Syndrome Diagnosed?

The road to proper treatment undoubtedly passes through accurate and complete diagnosis. For a patient presenting with shoulder pain, we begin with a detailed physical examination. We try to identify the point at which pain is triggered by lifting or rotating the arm at specific angles. However, since the shoulder is a complex and deep structure, manual examination alone does not reveal which tissue is affected, whether there is a tear, or the state of the bone structure.

This is where imaging techniques come in. X-rays provide information about the bone structure. We use them to look for signs of calcification, hooked acromion, or narrowing of the joint space. However, X-rays do not show soft tissues—the tendons, muscles, and bursae that actually cause pain.

To evaluate soft tissues in detail, Magnetic Resonance Imaging (MRI) is the gold standard. With MRI, we examine the shoulder slice by slice like a map. MRI helps us determine tendon quality, tear size, extent of edema, and presence of cysts. However, MRI also has a drawback: the patient must lie still inside the scanner. Yet, shoulder impingement syndrome is a dynamic problem that appears with movement.

Why Is Ultrasound Important for Dynamic Diagnosis?

This is precisely where ultrasonography, the strongest tool of interventional radiology, comes into play. Ultrasound allows us to observe the shoulder in motion. As the patient raises their arm, we can view in real time how the tendon passes under the bone, at what angle the impingement occurs, and how the bursa swells.

This is called “dynamic evaluation.” Everything may appear normal on an MRI because the patient is lying still with the arm by their side. But with ultrasound, when we say “now raise your arm,” we can catch the moment of impingement. This is extremely valuable information that increases diagnostic accuracy and guides treatment. Moreover, since ultrasound is an interactive examination performed while speaking to the patient and touching the painful area with the probe, it allows us to pinpoint the exact source of the pain.

What Is the Role of Interventional Radiology in the Treatment of Shoulder Impingement Syndrome?

Once the diagnosis is made, we move on to the treatment phase. For the majority of patients, the first recommended approaches include rest, pain relief medications, and physical therapy exercises. These methods are quite effective for mild impingement and edema. However, there is a significant group of patients whose pain does not subside after 3 to 6 months of conservative treatment, who struggle to lift their arms, and whose quality of life has deteriorated:

In traditional approaches, these patients are usually advised to undergo surgery (arthroscopic shoulder surgery). However, surgery requires anesthesia, has a long recovery period, and does not always offer a 100% guaranteed result. This is where interventional radiology—a modern discipline that bridges the gap between drug therapy and surgery—comes in. Our aim is to resolve the issue at its source without surgery, without disrupting the body’s integrity, and through a needle-sized entry point.

The key feature of interventional radiologic treatments is that they are performed under image guidance. In the past, shoulder injections were done “blindly,” relying on the physician’s anatomical knowledge. But the shoulder joint is complex, and the targeted space is millimetric. If the needle tip deviates by just a few millimeters, the medication is delivered to the wrong place, and the treatment becomes ineffective. We, on the other hand, use ultrasound screens to visualize the needle tip, blood vessels, nerves, and tendons. We deliver the medication to the problematic area with millimetric precision. This maximizes the treatment’s effectiveness and minimizes side effect risks.

Is Cortisone Injection Beneficial for Shoulder Impingement Syndrome?

Cortisone (corticosteroid) injections have been one of the most commonly used treatments for shoulder pain for many years. However, due to misinformation online, many patients fear this treatment. We frequently encounter questions like, “Does cortisone weaken bones?”, “Will it make me gain weight?”, “Will it rupture my tendon?”

First, let us clarify: in shoulder impingement syndrome, the main cause of pain is inflammation resulting from mechanical compression. Cortisone is the most powerful known anti-inflammatory agent in medicine. It acts like a firefighter, quickly extinguishing the inflammation, reducing edema, and decreasing swelling. When the swelling subsides, space opens up, impingement reduces, and the patient feels relief.

Cortisone becomes harmful when administered too frequently, in high doses, or mistakenly into the tendon itself. Injecting cortisone directly into the tendon may weaken it. However, as interventional radiologists, we ensure via ultrasound that the needle does not enter the tendon, but rather the bursa above it. Cortisone injections performed in the correct spot, at the appropriate dose, and no more than once or twice per year are very safe and effective, potentially avoiding surgery. Systemic side effects (such as weight gain) are almost non-existent at such low, localized doses.

What Kind of Solution Does PRP Therapy Offer for Shoulder Impingement Syndrome?

In recent years, medicine has shifted from merely suppressing symptoms to encouraging the body’s own healing processes—a field known as Regenerative Medicine. PRP (Platelet-Rich Plasma) therapy is one of the most popular and effective treatments in this field.

Shoulder tendons are tissues with relatively poor blood supply. Therefore, once damaged, they take a long time to heal or may not heal at all. In PRP therapy, we draw the patient’s own blood and process it using a special method. This separates and concentrates the “platelets” in the blood, which contain healing growth factors. We then inject this healing serum under ultrasound guidance directly onto the damaged tendon or tear.

While cortisone aims to reduce pain and inflammation, PRP aims to repair the damaged tissue. Especially when there is degeneration (tendinosis) or partial tears in the tendon, PRP stimulates biological healing of these tissues. This leads to not just temporary relief, but structural and lasting improvement. Since PRP is derived from the patient’s own blood, it carries no allergy or side effect risks.

PRP therapy is suitable for:

• Chronic tendon damage
• Partial tendon tears
• Patients who do not want cortisone
• Early-stage calcifications
• Sports injuries

Can the Hydrodilatation Method Prevent Frozen Shoulder?

If shoulder impingement syndrome is left untreated for a long time, the patient may stop using their arm due to pain. This inactivity causes the joint capsule to shrink and adhere, leading to a highly painful and restrictive condition known as Frozen Shoulder.

If a patient already has limited movement along with impingement, we apply a method called Hydrodilatation. Under ultrasound guidance, we enter the joint capsule and inject a mixture of saline, local anesthetic, and a low dose of cortisone. This procedure aims to expand the joint capsule from the inside, break adhesions, and wash the joint. A noticeable increase in range of motion is observed immediately after the procedure. This method is highly effective in preventing progression to frozen shoulder or reversing early-stage frozen shoulder.

Does Nerve Block Eliminate Shoulder Impingement Pain?

In some cases—especially when shoulder damage is advanced or when surgery is not an option (e.g., due to advanced age, heart disease)—our goal becomes to simply alleviate pain and help the patient live comfortably. This is where Suprascapular Nerve Block comes in.

We use ultrasound to reach the suprascapular nerve, the main nerve carrying pain from the shoulder, and perform a block using either radiofrequency (heat energy) or medication. This does not fix the mechanical problem in the shoulder, but it stops the pain signals going to the brain. Thus, the patient, even though still having a shoulder problem, does not feel pain, sleeps comfortably, and can perform daily activities.

What Happens After Shoulder Impingement Treatment?

Interventional radiologic treatments (injections) are typically performed in outpatient settings, do not require hospitalization, and take only 15–20 minutes. The patient can return home or to work immediately afterward. The post-treatment process varies depending on the treatment applied.

If cortisone was injected, effects generally begin quickly. There may be a mild feeling of fullness on the first day, but significant relief is usually seen within a few days. In PRP therapy, the process is different. Since PRP triggers the body’s healing mechanism, there may be a slight increase or fluctuation in pain during the first 1–2 weeks. This is expected and indicates that healing has begun. PRP’s actual regenerative effect begins around the third week and continues to improve over several months.

Regardless of which injection is performed, the treatment must be supported with physical therapy and exercise for lasting results. What we do is eliminate the pain so the patient can comfortably perform exercises. After the pain subsides, strengthening the muscles around the shoulder, correcting posture, and preventing recurrence of impingement is only possible through these exercises.

Why Should You Consult an Interventional Radiologist?

Shoulder pain is a complex issue, and its treatment requires a team effort. Orthopedics, Physical Therapy, and Interventional Radiology are all parts of this team. The role of Interventional Radiology is to be the “solution center” that combines medicine with technology.

When you consult an interventional radiologist, you don’t just get an exam. We also examine the inside of your shoulder in full detail via ultrasound, confirm your diagnosis on the spot, and if appropriate, apply treatment with millimetric precision during the same session. Instead of the typical routine of “get your scan, bring the results, and we’ll schedule something later,” we operate on a “see and treat” principle.

For patients who do not want surgery, haven’t benefited from physical therapy, or are tired of medications, these minimally invasive, image-guided treatments offer a powerful escape route before surgery. Your shoulder health is your quality of life. Rather than accepting a life with pain, making use of these opportunities offered by modern medicine is the smartest step toward a pain-free and active future.

Frequently Asked Questions

Prof. Dr. Özgür KILIÇKESMEZ

Prof. Dr. Özgür Kılıçkesmez is one of Türkiye’s leading interventional radiology and neuroradiology specialists, focusing on minimally invasive endovascular treatments. His primary areas of expertise include aneurysm and stroke treatments, embolization procedures, non-surgical treatments of thyroid and parathyroid diseases, interventional oncology, and peripheral vascular interventions. He currently serves as the Head of the Interventional Radiology and Neuroradiology Department at Istanbul Memorial Göztepe Hospital.
Graduating from Istanbul University Cerrahpaşa Faculty of Medicine in 1997, Prof. Dr. Kılıçkesmez received advanced training in interventional radiology and oncology as a Clinical Fellow at London Guy’s & St Thomas’ and King’s College Hospital between 2012 and 2013. He earned the title of Professor in 2020 and, in the same year, became the Founding Interventional Radiologist at SBÜ Çam and Sakura City Hospital. He also holds the EBIR (European Board of Interventional Radiology) certification.
Prof. Dr. Kılıçkesmez has 94 international and 40 national publications and over 2500 citations. He serves as a reviewer for prestigious journals such as the American Journal of Roentgenology (AJR) and Diagnostic & Interventional Radiology. With his clinical and academic expertise, he is a nationally and internationally recognized authority in stroke treatment, brain aneurysm, embolization, tumor ablation, and minimally invasive treatments of thyroid/parathyroid diseases.