Shoulder impingement has a way of dominating daily life. Reaching into the back seat, slipping on a jacket, sleeping on the painful side, even a quick swim can light up the front or side of the shoulder. Many patients arrive after months of rest, ice, oral anti-inflammatories, and standard physical therapy. Some find relief, others keep circling the same pattern: short-term improvement, then a flare. When rotator cuff tendons are frayed or inflamed, and the subacromial space is tight, a treatment that does more than blunt pain becomes attractive. That is where platelet rich plasma injection, a form of prp regenerative therapy, fits the problem.
PRP stands for platelet rich plasma. It is a concentrate of your own platelets suspended in a small volume of plasma, prepared from a simple blood draw. Platelets carry growth factors that influence cell signaling involved in inflammation, tissue repair, and angiogenesis. In orthopedic practice, we use prp injections as a biologic tool to nudge an injured tendon away from stagnation and toward healing. For shoulder impingement, the targets are usually the supraspinatus tendon, the subacromial bursa, or both.
What shoulder impingement really is
Impingement is a catch-all term. In the clinic, it ranges from pure bursitis with a smooth rotator cuff to a cuff with degenerative tendinopathy or partial-thickness tearing. The space under the acromion narrows during overhead motion and the structures glide or grind depending on their condition. Pain often sits at the lateral shoulder and radiates down the deltoid. The pattern is classic: pain reaching overhead or behind the back, painful arc between roughly 60 and 120 degrees of abduction, and night pain that wakes you if you roll onto the bad side. Weakness with resisted elevation may appear when tendinopathy crosses into tearing.
The drivers vary. For a desk worker, it can be posture with scapular dyskinesis and a stiff thoracic spine. For a painter or swimmer, it can be mileage and repetition on a frayed tendon. For those in their fifties and sixties, vascular changes and cumulative microtrauma play a role. Imaging helps refine the story. Ultrasound can spot bursal thickening, fluid, and tendon fibrillation. MRI can grade tendinosis and occult tears. The nuance matters because it guides whether a prp orthopedic injection is likely to help and where it should go.
Why PRP is worth a look
Corticosteroid injections have reigned for subacromial pain for decades. They reduce inflammation, often quickly, but the effect can fade within weeks to a few months. Repeated steroid exposure risks tendon weakening if overused. PRP therapy takes a different route. It aims to shift the biology of the tendon and bursa. In my practice, I think of prp treatment as a middle path between rest prp injection FL plus rehab and surgical decompression or cuff repair. Not a miracle, not a last resort, but an option when standard care underperforms and imaging shows tissue that could heal.
The evidence has matured. Randomized trials and meta-analyses looking at platelet rich plasma injection for rotator cuff tendinopathy show modest to meaningful improvements in pain and function at midterm follow up, most notable after 3 to 6 months. Benefit is stronger in chronic tendinopathy without full-thickness tears, and when the injection is guided with ultrasound to the exact site of disease. The effect size is not uniform across studies because PRP is not one product. Platelet concentration varies, leukocyte content varies, and so do preparation techniques. That variability explains some of the debate. Still, the signal is consistent enough to offer prp joint therapy for the right patient with shoulder impingement mechanics.
How a PRP injection is prepared and placed
The prp procedure is straightforward but details matter. If the patient has used NSAIDs in the Find more information previous week, I ask them to stop if safely possible, since drugs like ibuprofen can mute platelet activation. We draw blood, typically 30 to 60 milliliters, into anticoagulant tubes. The sample spins in a centrifuge to separate components. The goal is to harvest a small volume of plasma with a higher-than-baseline platelet count, often 3 to 6 times the starting concentration. Depending on the device, you can produce leukocyte-poor or leukocyte-rich PRP. For subacromial bursitis and superficial tendinopathy, I lean toward leukocyte-poor PRP to minimize post-injection flare. For deeper tendon work, some clinicians use leukocyte-rich preparations. The choice should reflect the target tissue and your tolerance for short-term inflammation.
Injection technique drives outcomes. In the shoulder, ultrasound guidance is not a luxury, it is the standard. With the patient seated or side-lying, the probe maps the acromion, the subacromial bursa, and the rotator cuff footprint. If the primary pathology is bursal, we place the platelet therapy injection into the thickened bursa. If the supraspinatus tendon shows hypoechoic zones consistent with tendinopathy, a percutaneous needle fenestration or tenotomy can be combined with PRP to stimulate a controlled healing response. The total volume is small, often 3 to 5 milliliters. Anesthetic, if used, should be minimal and kept away from the PRP itself to avoid impairing platelet function. Many of us avoid corticosteroid admixture for the same reason.
The visit takes about 45 to 60 minutes, including consent, draw, processing, and injection. Most patients tolerate it without sedation. Soreness afterward is normal. Ice and acetaminophen are fine, but avoid NSAIDs for at least a week to let the inflammatory cascade run its early course. Sling use is not necessary beyond comfort for the first day or two.
What to expect after PRP for impingement
Recovery follows a predictable arc. There can be a 2 to 5 day period of increased ache, sometimes longer if we performed tendon fenestration. Function often dips briefly, then returns to baseline within 1 to 2 weeks. The next phase brings gradual improvement across 4 to 12 weeks. Many patients notice changes at the 6-week mark that are subtle but clear: less night pain, fewer catches in the painful arc, more tolerance for light overhead work. The full effect of a prp healing injection often lands between 3 and 6 months.
I tell patients to treat those first two weeks as a reset. Do not test the shoulder. We maintain gentle range of motion and scapular activation. Formal rehabilitation resumes in stages, guided by pain. The physical therapy program should focus on scapular mechanics, rotator cuff endurance, and thoracic mobility, not just isolated band work. A therapist who watches how you raise your arm and fixes the shrug pattern can save you from chasing symptoms.
A single treatment may suffice. In recalcitrant cases, a second prp injection at 8 to 12 weeks can carry the gains forward. I rarely recommend three unless there was a clear response to the first two and a plateau just short of the goal.
Who is a good candidate
Patient selection matters more than the brand of centrifuge. The best candidate has clinical impingement, imaging that shows rotator cuff tendinopathy without a full-thickness tear, and symptoms that persist despite a solid trial of activity modification and targeted therapy. Age alone is not a disqualifier, but biology changes, and expectations should as well. A 28-year-old volleyball player with high-demand overhead activity may bounce back faster than a 62-year-old carpenter with decades of load on a tendon already thinned. Both can improve, the curves look different.
Caution is needed when the dominant issue is structural encroachment, like a big acromial spur grinding a bulky bursa, or when there is a retracted full-thickness tear. PRP therapy cannot close a large gap or enlarge subacromial space. In those settings, it might serve as a bridge while you decide on surgery, or as an adjunct to healing after a repair, but it is not a substitute for fixing anatomy that cannot function.
Comorbidities affect outcomes. Poorly controlled diabetes, smoking, and high-dose statins correlate with slower or smaller responses. Anticoagulation is not a hard stop, yet we discuss bruising risk and coordinate with the prescribing clinician if any pause is possible. Allergies are rare because this is an autologous therapy, your blood back to you, but sensitivities to antiseptics or bandage adhesives should be addressed.
PRP versus steroid, dry needling, and surgery
The comparison patients ask for most often is prp injection versus steroid. Steroid acts fast, PRP acts slow. Steroid may calm a hot bursa so well that therapy gains traction and the process ends there. But two or three steroid shots over a year can leave a tendon weaker, and we sometimes see a temporary high followed by a disappointing slide. PRP’s early days can be bumpy, then the curve bends upward and often stays there. In head-to-head trials for rotator cuff tendinopathy, PRP tends to outperform steroid after the 3-month point on pain and functional scores, with fewer recurrences over 6 to 12 months.
Dry needling or percutaneous tenotomy without biologics can work, especially in tendinopathy with poor neovascularization. The mechanical stimulus alone can trigger healing. Adding platelet rich plasma treatment may augment the effect with growth factors. A fair take: if cost is a barrier, tenotomy alone is a sensible step. If you can invest in PRP, it may deepen and prolong the response.
Surgery has its place. If you have a full-thickness rotator cuff tear that retracts and weakens the arm, or if months of nonoperative care fail with marked functional limits, a repair or a decompression can solve the mechanical conflict directly. I have seen PRP used as an adjunct at the time of cuff repair to enhance tendon healing at the bone, with promising but still evolving evidence. PRP as a stand-alone for severe structural disease is a mismatch.
A realistic look at risks and downsides
PRP is not risk-free, though adverse events are uncommon. The typical reaction is a pain flare, mild swelling, and stiffness for several days. Infection is rare, similar to any sterile injection. Bruising can appear along the deltoid if the needle crosses small vessels. Nerve injury is very unlikely with proper guidance. Allergic reactions to your own plasma do not happen, but reactions to prep solutions or latex can.
The most cited downside is cost. Insurance coverage for platelet rich plasma therapy remains inconsistent. Some plans cover PRP for specific indications, many do not. Patients often pay out of pocket. The range varies by region and practice, commonly several hundred to over a thousand dollars per session, depending on the system used and whether ultrasound is included.
Another issue is inconsistency across PRP systems. Not all prp plasma injection products are the same. Platelet counts differ, white cell content differs, activation protocols differ. An experienced clinician should know what they are using and why. Ask. If you hear hand-waving, look elsewhere.
How it fits with a full rehab plan
A prp orthopedic injection is not a free pass to skip the work. The biology needs mechanics to follow. I anchor the plan around three phases. First, protect and calm the shoulder for one to two weeks, limit overhead loads and weights, keep the scapula moving and the neck and thoracic spine mobile. Second, gradually build capacity with isometrics, then isotonic cuff work in scapular plane ranges that do not provoke the painful arc. Close attention goes to serratus anterior and lower trapezius activation. Third, expose the tissue to graded overhead demands that mimic your sport or job. The increments matter. Ten minutes of light overhead brushing work can be a test. Two hours of painting trim is a setback waiting to happen.
Sleep and daily ergonomics are part of the treatment. Side sleepers can use a small pillow under the upper arm to prevent adduction torque on the cuff. Desk workers can adjust chair height and keyboard reach to avoid protracted scapulae and downward sloping shoulders that close the subacromial space. None of this is glamorous. It is how healing sticks.
Practical expectations set by case type
Not all impingement looks the same. A runner in her forties who started a pull-up challenge and now has lateral shoulder pain with a clean MRI apart from mild tendinosis often responds briskly. One PRP session combined with scapular control work and a sane return to pulling can quiet things in a few months. A professional painter with bilateral impingement, thickened bursae, and moderate supraspinatus tendinopathy may need a two-stage approach: first injection on the dominant side, structured time off from overhead work with modified duties, close physical therapy, then a second injection at 10 weeks if improvement reaches 60 to 70 percent but stalls short of job demands. A tennis player with internal impingement mechanics and posterior capsular tightness improves when the posterior capsule is addressed. If you chase the painful bursa but ignore the tight capsule and scapular timing, relief fades.
These scenarios are not theory. They reflect patterns I have seen in clinic and on the rehab floor. The lesson is simple: match the biology with PRP, match the mechanics with skillful therapy, and match the load with prudent progression.
Where PRP sits among other PRP uses
Patients sometimes ask about PRP because they heard of prp for knees or prp for hair loss. The same core principle applies across tissues. Platelet rich plasma treatment can modulate inflammation and stimulate repair for tendons, ligaments, and mild osteoarthritis. The preparation may differ. For intra-articular use such as prp for joint pain in mild knee OA, leukocyte-poor PRP is common. For tendon treatment like prp tendon treatment of the patellar or Achilles tendon, some clinicians favor higher platelet concentrations. Outside orthopedics, there is prp for skin and prp facial procedures, including prp microneedling, prp with microneedling for acne scars, or the so-called prp vampire facial, as well as prp for under eyes to address dark circles or fine lines through collagen stimulation. Those aesthetic uses sit in a different lane than prp orthopedic therapy for impingement, but the shared mechanism is growth factor delivery and signaling to resident cells.
It can be tempting to view PRP as a universal fixer. It is not. In the shoulder, it works best when inflammation and degeneration are present without a complete mechanical failure. Rotator cuff tendinopathy, subacromial bursitis, biceps tendinopathy near the groove, these are realistic targets. A delaminated, retracted cuff tear that cannot generate force needs a surgical plan, not a vial of platelets.
Step-by-step snapshot of the patient journey
- Evaluation and imaging: clinical exam, targeted ultrasound or MRI to define bursa and tendon status. Pre-procedure prep: discuss goals, hold NSAIDs if safe for 5 to 7 days, plan post-injection activity. PRP preparation and injection: blood draw, centrifuge to create platelet rich plasma, ultrasound-guided placement into bursa and/or tendon with or without fenestration. Early recovery: expect soreness 2 to 5 days, avoid NSAIDs, use ice and acetaminophen, maintain gentle range. Rehab and return: structured therapy from week 1 or 2, progressive loading, reassess at 6 and 12 weeks, consider a second injection if gains plateau before goals are met.
Questions worth asking your clinician
- What type of PRP do you use for shoulder tendinopathy, and why that preparation? Will you use ultrasound guidance to place the injection at the exact site of pathology? How do you structure rehab after the injection, and who coordinates it? What outcomes do you see in cases like mine, and over what time frame? If PRP does not deliver, what are the next steps?
Patients who get clear answers tend to do better, not because the biology changes, but because expectations align with the process.
A brief word on relative contraindications and medications
If you are on dual antiplatelet therapy after a stent, or anticoagulation for a clotting history, the decision to proceed involves a risk discussion and sometimes coordination with cardiology. Many patients can continue their medication and accept a slightly higher bruising risk. Those on chronic steroids or immunosuppressants may still benefit, though the healing response can be blunted. Uncontrolled diabetes and smoking slow tendon healing; optimization helps.
Supplements that affect platelets, such as high-dose fish oil, may increase bruising. I do not require stopping them in most cases, but I do inform patients about the small effect. After the injection, I advise against NSAIDs for one week, sometimes two. That window lets platelets do their early job without interference.
Measuring success beyond pain scores
Pain is the headline. Function is the story. Good outcomes after a prp regenerative injection for shoulder impingement include reduction of night pain, return of overhead range without a painful arc, improved endurance for repetitive tasks, and increased confidence with the arm overhead. For athletes, this can be measured in serves per session or pull-ups per set without symptom escalation. For workers, it might be hours of overhead painting or stocking before fatigue and pain return.
We track these measures at 6, 12, and 24 weeks. The curve does not need to be linear. Plateaus happen. A small step back during new loading can be normal. What matters is the overall trend and the ability to progress loads without sharp spikes. If the trend stalls and pain stays focal at the cuff footprint, we revisit imaging, technique, and mechanics. Sometimes a second PRP session or a targeted percutaneous tenotomy restarts the process. Sometimes a surgical consult is the right next move.
Final perspective from the treatment room
When done for the right indication, platelet rich plasma therapy can shift a stubborn shoulder away from chronic impingement and toward durable function. The procedure is brief, the risks are low, and the gains accumulate when paired with precise rehabilitation. It is not a quick fix, and it is not the right tool for a torn tendon that needs repair. It sits well for patients who have tried conventional care and remain stuck, who want to avoid or delay surgery, and who are willing to follow a plan over months, not days.
If you are considering PRP, bring your story, your imaging if you have it, and your goals. Ask about the prp injection procedure details, the type of preparation, and the plan after the shot. Make sure the conversation includes your daily demands, not just test results. A well-placed prp regenerative injection can calm a thickened bursa, feed a degenerating tendon, and give you a runway to rebuild how your shoulder moves. That combination, biology plus mechanics, is how you get past impingement and back to the things you enjoy.