PRP Therapy: The Complete Guide to Platelet-Rich Plasma Treatment

PRP Therapy: What the Evidence Shows

If you are weighing your options for chronic knee, shoulder, or back pain in Gilbert, AZ or the greater Phoenix area, this guide covers what you need to know about ultrasound-guided, non-surgical PRP therapy for chronic joint, tendon, and nerve pain.

Maybe you have already been through physical therapy, chiropractic care, a cortisone shot or two that helped for a while and then wore off, and a surgical consult where an operation was presented as the next step, but chronic pain that has outlasted all of those treatments often means the actual source was never fully identified. Identifying it is exactly what this guide, and our evaluation process, is built around.

PRP therapy is not a one-size-fits-all injection. The dose, preparation quality, placement precision, and accuracy of the diagnosis all determine whether the treatment works.

What is PRP therapy? Platelet-rich plasma therapy is a regenerative injection treatment that concentrates platelets from your own blood and delivers them, under ultrasound guidance, into the specific tissues causing your pain. At Regenerative Performance in Gilbert, AZ, Dr. Drew Timmermans, ND, RMSK, performs a thorough 2-hour evaluation before any procedure to identify exactly which structures need treatment. PRP is not appropriate for every patient or every condition. Individual results may vary.

If you have been living with chronic pain and want to find out what is actually driving it, the first step is a thorough diagnostic evaluation. The goal of your 2-hour evaluation is for you to walk out with the most specific structure-level diagnosis the findings support, a personalized treatment plan, and a clear answer on whether PRP is appropriate for your case. There is no pressure to schedule a procedure on the spot, and the goal of the first visit is clarity.

In our patient outcome registry, more than 7 out of 10 patients achieve meaningful improvement in the daily activities they came to us to recover (registry data updated July 2026); individual results may vary.

We limit how many new regenerative patients we accept each month to devote sufficient time and attention to each case.

Many of our patients have spent months or years cycling through cortisone injections, physical therapy, and specialist visits that lasted 7 minutes. That is usually the point at which they find us. After properly dosed, image-guided PRP combined with strength-focused rehabilitation, several have gone on to report years of meaningful improvement.

What Is PRP Therapy?

PRP stands for platelet-rich plasma. It is a concentration of your own blood platelets, prepared the same day as your procedure from a dedicated blood draw that is larger in volume than the small samples used for routine diagnostic lab work. Platelets contain growth factors and signaling molecules which the body can use to support tissue repair. Most of the chronic injuries we treat have stalled: the original healing response ran its course without finishing the job. When concentrated platelets are delivered to that injured area, the goal is to re-stimulate a new healing response in tissue that has stopped healing on its own.

PRP therapy falls under the broader category of orthobiologic medicine, which uses biological substances from your own body to support tissue healing. Unlike cortisone, which suppresses inflammation and masks pain temporarily, or surgery, which restructures tissue mechanically, PRP works with your body's own repair mechanisms.

The concept is straightforward: concentrate the repair elements from your blood and deliver them directly to the tissue that needs them. The execution, however, varies enormously between clinics, which is why PRP results range from substantial improvement to disappointing depending on who performs the treatment and how they do it.

How Does PRP Work?

PRP works by concentrating your body's own repair cells and growth factors, then delivering them precisely to the damaged tissue. Here is a summary of the process and biology before the detailed explanation.

• Blood is drawn (120-300 mL at top tier clinics, compared to 60 mL or less at many other practices)
• The blood is processed in a centrifuge to isolate the plasma layer that is rich in platelets
• The concentrated PRP is injected under ultrasound and/or x-ray guidance into the specific tissues causing pain
• Platelets release growth factors that research suggests trigger a three-phase healing cascade over weeks and months

The Biology Behind PRP

When concentrated platelets contact injured tissue, they release growth factors including platelet-derived growth factor (PDGF), transforming growth factor beta (TGF-B), vascular endothelial growth factor (VEGF), and insulin-like growth factor (IGF). These growth factors support the three phases of the wound-healing and repair cascade: inflammation, proliferation, and remodeling (Everts et al., International Journal of Molecular Sciences, 2020).

Phase 1: Inflammation (days 1-7). The injection triggers a controlled inflammatory response. This is why you may feel increased soreness for the first several days. This inflammation is productive, as it recruits repair cells to the area and clears damaged tissue.

Phase 2: Repair (weeks 2-8). New collagen and tissue begin forming at the injection site. Pain typically starts decreasing during this window. Many patients notice the first meaningful changes around the 4-week mark.

Phase 3: Remodeling (months 2-9+). The new tissue matures and strengthens. Function continues improving. In our registry, pain reduction continues through 18 months, reaching 59% mean reduction at that timepoint.

The Blood Draw and Preparation

The amount of blood drawn sets a ceiling on the total platelet dose available for your treatment. The right draw volume depends on how many structures we are treating and the dose target for each one, which is why we typically draw 120-300 mL rather than the much smaller volumes common elsewhere.

A 2024 systematic review and meta-analysis in Current Reviews in Musculoskeletal Medicine identified an optimal threshold of more than 10 billion platelets for favorable clinical outcomes after PRP injections for knee osteoarthritis (Berrigan et al., 2024). That threshold is specific to the knee: the right dose target changes with the condition and the size of the structure being treated, so a partial-thickness ligament tear or a small joint like the base of the thumb calls for a different target than a large joint like the knee.

The blood is then processed in a centrifuge to separate the platelet-rich layer from red blood cells and platelet-poor plasma. The quality of this separation matters. We test each sample in-house, measuring platelet, white blood cell, and red blood cell counts in your baseline blood and again in the final PRP preparation, to confirm the platelet count meets therapeutic levels. Many clinics skip this step entirely.

What Conditions Can PRP Treat?

PRP therapy has been studied for a wide range of musculoskeletal conditions. The strongest evidence exists for osteoarthritis, tendon injuries, and ligament damage. Here are the conditions we most commonly treat at our clinic, along with outcomes from our patient registry.

The following data comes from our practice registry: more than 340 tracked cases across more than 200 patients over more than 5 years, with registry data updated July 2026. These are real patient outcomes from our registry, not results from a randomized controlled trial.

PRP for Knee Osteoarthritis

Knee OA is the most common condition we treat. In our registry:

• 79% of knee patients report significant pain relief by 18 months in our registry, building from 64% at 6 months
• Relief holds at 71% through 24 months
• Across all body parts, 75% of osteoarthritis cases achieve significant pain relief, with an average pain reduction of 53%

A 2024 systematic review and meta-analysis of randomized controlled trials in The American Journal of Sports Medicine suggests that patients treated with PRP were more than twice as likely to have a successful outcome as those treated with hyaluronic acid for knee osteoarthritis (Oeding et al., 2024). A separate 5-year randomized trial indicates that significantly fewer patients treated with PRP went on to need another injection or procedure for their knee by 24 months than those treated with hyaluronic acid (22.6% vs. 37.1%) (Di Martino et al., 2019).

PRP for Shoulder Pain and Rotator Cuff Injuries

Shoulder cases are among the most common in our registry, with some of the most striking outcomes.

• 74% of shoulder patients report significant pain relief at 6 months, climbing to 82% by 18 months
• Nearly 9 out of 10 shoulder patients report significant pain relief at 24 months

PRP injections may support healing in partial-thickness rotator cuff tears: one randomized trial suggests that PRP injected directly into the tear reduced partial-thickness supraspinatus tear size, while a corticosteroid injection into the space above the tendon did not significantly affect tear size (Tanpowpong et al., Sports Medicine - Open, 2023). This structural effect may reduce the need for surgical repair in appropriately selected patients.

Low Back Pain (Lumbosacral/Pelvis)

Low back is our second most-treated body part, and the recovery timeline tends to run longer than for some other areas.

• 74% of low-back patients report significant pain relief at 12 months in our registry
• Relief holds at 77% through 18 months
• Results hold up across disc, facet, and SI joint diagnoses

Published research points in the same direction. In a randomized trial of ultrasound-guided sacroiliac joint injections for chronic low back pain, 90% of patients treated with PRP still had relief at 3 months, compared with 25% of those treated with steroid (Singla et al., 2017).

For detailed information on PRP for back conditions, see our resource on SI joint treatment.

Tendon Injuries (Achilles, Patellar, Gluteal, Elbow)

Tendinosis responds particularly well to PRP in our registry.

• 77% of tendinosis cases achieve significant pain relief, with an average pain reduction of 62%
• 74% of partial-thickness tendon tear cases report significant pain relief
• Tendinosis is one of the strongest-performing diagnoses in our registry

For rotator cuff tendinopathy, a single PRP injection produced superior and sustained improvement in pain and function compared with a corticosteroid injection at 12 months (Rossi et al., 2024), and PRP outperformed corticosteroid for long-term pain relief and function in chronic plantar fasciitis (Kumar et al., 2024).

Nerve Pain and Entrapments

Compressed nerves are treated with nerve hydrodissection, a technique that injects fluid (typically properly dosed PRP, protein concentrate, or both, depending on your diagnosis) around the compressed nerve in a full ring, lifting away the tissue pressing on it so the nerve can glide better.

We treat specific, ultrasound-identifiable nerve entrapments, such as carpal tunnel syndrome (the median nerve at the wrist), and candidacy for nerve work is confirmed at the evaluation.

For carpal tunnel syndrome specifically, a single ultrasound-guided PRP injection around the median nerve was safe and effective in a prospective randomized trial (Wu et al., 2017), and a separate randomized trial in moderate-to-severe carpal tunnel syndrome indicates that a single ultrasound-guided PRP injection provided therapeutic benefit lasting a full year (Chen et al., 2021).

Additional Conditions

PRP is also used for a number of other conditions we track in our registry:

• Hip pain (including hip osteoarthritis and labral conditions): 89% of hip patients report significant pain relief at 6 months, with a 48% average reduction in pain
• Ankle injuries (including ligament sprains): 46% average reduction in pain, with about 6 out of 10 patients achieving significant pain relief
• Wrist and hand osteoarthritis: more than 95% of wrist and hand patients followed past 12 months report significant pain relief
• Cervical spine (neck) conditions: 29% average reduction in pain, with a 33% average improvement in neck-related disability on the validated NDI scale
• Thoracic spine (mid-back): 56% average reduction in pain, with 2 out of 3 patients reaching significant pain relief

Beyond the conditions listed above, PRP treats orthopedic injuries across the entire body.

How Does PRP Compare to Cortisone, Surgery, and Other Treatments?

PRP, cortisone, and surgery approach the problem differently: PRP supports lasting tissue repair for 18 to 24 months or longer with no degradation from repeated use, cortisone suppresses inflammation for days to a few months (often a shorter stretch with each repeat injection) and can weaken tissue with repeated use, and surgery corrects the structure mechanically, with a longer recovery and permanent structural change. The table below compares these options directly.

Why We Almost Never Recommend Cortisone

Cortisone injections are effective at temporarily reducing pain, and there are situations where they are the right choice. But for chronic musculoskeletal conditions, relief tends to shrink with each round: the first shot may help for months, the next for weeks, and eventually they often stop working altogether.

A 2017 randomized trial in JAMA indicates that intra-articular triamcinolone (a corticosteroid) caused significantly greater knee cartilage thickness loss than saline over two years (-0.21 mm vs. -0.10 mm) (McAlindon et al., 2017). That study looked at the knee, and the concern may extend to other joints. For load-bearing tendons, we advise against corticosteroid injection into or around the tendon entirely: cortisone can weaken tendon tissue, and for a tendon under high mechanical load, the rupture risk is not worth the short-term relief.

Cortisone suppresses inflammation, which can be temporarily helpful if inflammation is driving symptoms. But in chronic conditions where tissue damage is the underlying issue, suppressing inflammation does not fix anything. It masks the pain temporarily while the structural problem remains, and potentially worsens.

PRP takes the opposite approach. Instead of suppressing the healing response, it amplifies it. The tradeoff is that PRP takes longer to produce results (weeks to months versus days for cortisone), but the goal is repair, not temporary symptom relief.

PRP vs. Surgery

For many patients, PRP is not just a stop along the road to surgery. It can help them avoid surgery altogether: when PRP meaningfully reduces the pain that was driving the surgical conversation, the operation is often no longer needed. Some conditions (complete tendon ruptures, advanced bone-on-bone arthritis with joint misalignment, structural instability requiring mechanical repair) still need surgery. But many patients who are told they "need surgery" have conditions that fall into a gray area where PRP may produce enough improvement to change that.

In our registry, a substantial share of patients return to treat additional body areas, suggesting that the first treatment produced enough benefit to pursue more. Individual results may vary, and we confirm whether PRP or another approach is appropriate during the evaluation.

PRP vs. Stem Cell Therapy

In our experience, PRP and stem cell therapy typically land at similar pain relief, but they get there differently: PRP usually needs more treatments, while stem cell therapy reaches the same result sooner with a single treatment. Collecting for PRP also asks less of you, a straightforward blood draw instead of harvesting bone marrow or fat, and it typically costs less. For patients who would do better with stem cell therapy but cannot afford it, PRP is a strong option. Cost never steers the diagnosis or the tissue-based recommendation, but it is a legitimate part of planning treatment, and we discuss it openly.

PRP Combined with Physical Therapy

PRP and physical therapy are not competing treatments. They complement each other. PRP supports the biological repair process, while strength-focused rehabilitation ensures the repaired tissue can handle the demands of daily life and activity.

The best long-term outcomes in our practice come from patients who commit to both: the procedure as the catalyst, and the daily rehabilitation work as the driver of lasting improvement. Your body can heal itself. The procedure creates the conditions for that healing. Your work afterward determines how far it goes.

Why Does PRP Dosing Matter?

The number of platelets in your PRP injection is one of the most important factors determining whether treatment works; unfortunately, many clinics do not measure this. Underdosed PRP may provide temporary relief, but it is far less likely to produce a lasting response.

• Published research in knee osteoarthritis identifies an optimal threshold of more than 10 billion platelets for favorable outcomes (Berrigan et al., 2024); the right dose target varies by condition and by the size of the structure being treated
• A randomized trial in knee osteoarthritis reached a similar conclusion: PRP standardized to a dose of 10 billion platelets improved functional outcomes and protected the joint cartilage from further wear (Bansal et al., 2021)
• The disc-dose evidence points the same way: patients treated with higher-concentration intradiscal PRP for chronic lumbar disc pain reported being satisfied with treatment more often than those treated with lower-concentration PRP. The difference was significant, 81% versus 55% (Lutz et al., 2022)
• Many clinics draw 60 mL of blood or less, limiting how many platelets they can concentrate
• We typically draw 120-300 mL, depending on how many structures are being treated and the dose target for each

We verify every preparation in-house by measuring platelet, white blood cell, and red blood cell counts in the baseline blood draw and again in the final PRP sample, so we know the platelet dose you actually received.

To be clear, an unmeasured preparation can still work. Positive results have been published in studies that did not measure platelet dose. What the research suggests is that there appears to be an optimal platelet dose that increases the share of patients who respond and the size of the response they get. A clinic that never measures its preparations cannot know whether yours reached that range.

Why Does Ultrasound Guidance Matter for PRP Injections?

Ultrasound guidance determines whether the PRP actually reaches the structure causing your pain. Where the PRP goes matters as much as what is in it, and a high-quality PRP preparation injected into the wrong tissue will not produce results.

Needle misplacement is a documented risk for common joints when injections are performed without imaging guidance. A blind injection into "the general area" of your knee, shoulder, or spine does not guarantee the PRP reaches the specific structure causing your pain.

Instead of placing a single injection into the joint space and hoping it covers everything, we use ultrasound to place PRP into each structure that is actually painful: the joint, ligaments, tendons, fat pad, and irritated nerves.

Dr. Timmermans holds the RMSK credential (Registered in Musculoskeletal Sonography), one of the few certifications specifically validating advanced competency in diagnostic and interventional musculoskeletal ultrasound. Tendon, ligament, and nerve injections at our clinic are performed under ultrasound guidance. Joint injections are guided by ultrasound, with x-ray (fluoroscopy) confirmation added when the structure requires it, and most spinal injections are performed under x-ray guidance.

What to Expect at Our Gilbert, AZ PRP Clinic

Treatment at our clinic follows four steps: a 2-hour diagnostic evaluation, an individualized treatment plan, the PRP procedure itself (blood draw, preparation, and image-guided injection in a single visit), and recovery with strength-focused rehabilitation and ongoing outcome tracking.

Among the cases with completed safety follow-up in our registry, zero severe treatment-related adverse events have been reported. If PRP is not appropriate for your case, we will tell you directly at the evaluation.

How Long Do PRP Results Last?

In appropriately selected patients treated with adequate platelet dose and precise ultrasound-guided placement, PRP results can last 18 to 24 months or longer. In our registry, pain reduction continues to improve over time rather than fading.

Here is how pain reduction progresses in the average patient in our outcome data:

• 1 month: 25% mean pain reduction
• 6 months: 36% mean pain reduction
• 12 months: 45% mean pain reduction
• 18 months: 59% mean pain reduction

This timeline is why we do not judge PRP results at 2 weeks. The biological repair process takes months to complete. Patients who commit to strength-focused rehabilitation during this period tend to see the best long-term outcomes.

Several factors affect how long results last:

• Condition severity and chronicity: Patients who begin treatment within 6 months of symptom onset reach significant pain relief at rates of 85 to 88%, compared with 58% for those who wait more than a year
• Rehabilitation adherence: Patients who complete strength-focused physical therapy extend and amplify their results
• Treatment approach: Some cases call for more than one biologic; in our registry, combination protocols show a 74% significant-pain-relief rate versus 60% for single-agent treatment (observed outcomes across different case types, not a head-to-head trial)
• PRP dose and quality: Higher platelet concentrations correlate with better and more durable outcomes

What Does the Evidence Say About PRP?

PRP therapy is one of the most studied regenerative treatments in orthopedic medicine, and the evidence is strongest for knee osteoarthritis and tendon conditions, where systematic reviews and randomized trials suggest benefit over hyaluronic acid and corticosteroid injections in appropriately selected patients.

• Systematic reviews and meta-analyses indicate PRP is superior to hyaluronic acid and placebo for knee osteoarthritis
• Randomized-trial evidence exists for tendon injuries, ligament damage, and certain spine conditions
• PRP is not an FDA-approved treatment for any specific orthopedic condition. In the United States it is typically an off-label use of devices cleared to prepare platelet concentrates
• The quality of evidence is growing, but PRP research is complicated by the lack of standardized preparation protocols across studies

Published Research

A 2024 systematic review and meta-analysis of randomized controlled trials in The American Journal of Sports Medicine suggests that PRP produced significantly higher rates of successful outcomes than hyaluronic acid and other alternative injections for knee osteoarthritis (Oeding et al., 2024).

For tendon and tendon-adjacent conditions, randomized trials indicate benefit in several settings: a single PRP injection outperformed corticosteroid for rotator cuff tendinopathy at 12 months (Rossi et al., 2024), and PRP outperformed corticosteroid for long-term pain relief and function in chronic plantar fasciitis (Kumar et al., 2024). The results are not uniform across every tendon and every protocol, which is part of why diagnosis, dose, and placement matter so much.

PRP may also slow structural progression in mild-to-moderate knee osteoarthritis: in one randomized trial, cartilage thickness on MRI remained unchanged at one year in 82.8% of PRP-treated knees, compared with 61.7% of knees treated with hyaluronic acid (Bansal et al., 2021).

PRP injection technique, platelet concentration, and the number of injections all appear to influence clinical outcomes, which helps explain why PRP results vary so dramatically between clinics.

Our Practice Outcomes

We are partnered with DataBiologics, tracking real patient outcomes with independently collected data. Here are the headline numbers from our registry, with data updated July 2026.

• Pain relief: 77% of eligible patients achieve clinically meaningful pain relief (50% or greater pain reduction or best score of 2 or below)
• Function improvement: More than 7 out of 10 patients achieve clinically meaningful improvement in daily function (10+ point improvement on the Desired Functionality scale)
• Worst pain reduction: 7 out of 10 patients see their worst pain drop by a clinically meaningful amount
• Safety: Zero severe treatment-related adverse events among the cases with completed safety follow-up
• Pain over time: Improvement continues through 18 months (59% mean reduction)
• Repeat treatment: A substantial share of patients return to treat additional body areas

Patient satisfaction is tracked separately from these clinical outcomes. In our registry, 92% of cases with a completed six-month satisfaction survey were rated satisfied or extremely satisfied. At twelve months, 95% of completed case responses were also rated satisfied or extremely satisfied.

Who Is a Good Candidate for PRP Therapy in Gilbert, AZ?

A good candidate for PRP is an adult with chronic musculoskeletal pain that has not improved with conservative care such as physical therapy, medications, or cortisone. PRP is not appropriate for everyone, but here is what we typically see in patients who respond well.

• Chronic musculoskeletal pain lasting 3 or more months
• Failed conservative care such as physical therapy, chiropractic, massage, or medications
• Cortisone injections that helped temporarily but wore off or stopped working
• Partial-thickness tendon tears, ligament sprains, osteoarthritis, or disc injuries confirmed during the diagnostic workup
• Looking for a non-surgical option before considering surgery
• Want structure-specific treatment targeting exact joints, ligaments, tendons, or nerves
• Willing to invest in out-of-pocket treatment
• Committed to post-procedure rehabilitation and strength work

Our clinic is in Gilbert, AZ. Patients travel to us from out of state and internationally, and for those patients we schedule the evaluation and the procedure in a single trip.

As with any injection procedure, mild soreness and swelling in the days afterward are common and expected. Your evaluation will cover the individual risk factors specific to your case.

In our clinic, we most often see active adults 40 and older with chronic tendinosis, osteoarthritis, or ligament instability who have tried physical therapy and cortisone without lasting relief and want to avoid surgery.

Our data also shows that earlier treatment produces better results. Patients who begin treatment within 6 months of symptom onset reach significant pain relief at rates of 85 to 88%, compared with 58% for those who wait more than a year. Waiting does not disqualify you from treatment, but earlier intervention is associated with the strongest outcomes.

During your first visit, we confirm whether PRP or another approach is appropriate and discuss other options if it is not.

Who Is NOT a Good Candidate for PRP?

PRP is not appropriate for patients with an active infection at the treatment site, certain blood and platelet disorders, active cancer at the treatment site, or complete tears that need surgical repair. Being direct about who we do not recommend PRP for is just as important as explaining who benefits, so here is the full list.

• Active infection at or near the treatment site
• Blood disorders affecting platelet function or count (thrombocytopenia, platelet dysfunction syndromes)
• Active cancer at the treatment site (growth factors could theoretically promote tumor growth)
• Complete tendon or ligament ruptures requiring surgical repair (PRP supports partial injuries; complete tears typically need mechanical reconstruction)
• Advanced bone-on-bone arthritis with joint misalignment (bone-on-bone changes alone do not rule out PRP or stem cell therapy, but when the joint is also misaligned, surgery is often the right recommendation because the misalignment itself needs mechanical correction)
• Patients expecting the injection alone to do all the work (many patients improve without formal physical therapy, but strength-focused rehabilitation consistently produces better and longer-lasting results)
• Patients taking certain blood thinners that cannot be safely adjusted (whether this matters depends on which blood thinner you take and which region of the body is being treated; we review this at the evaluation)
• Unrealistic expectations about outcomes (PRP produces meaningful improvement in most patients, but it does not produce complete resolution of symptoms in everyone)

If you fall into any of these categories, we will tell you directly during the evaluation. We recommend the right treatment for the patient, not the most expensive one. If PRP is not the right call, we will explain why and discuss alternatives.

For patients who are good candidates, treatment outcomes in our registry are strong. Improvement typically starts in the first few months and then holds: nearly four out of five knee patients report significant pain relief by 18 months after treatment, and roughly 3 out of 4 low-back patients report significant pain relief by 12 months after treatment. Individual results may vary.

If your situation does not fit neatly into any of the above, a 2-hour evaluation will give you a direct answer. Call 480-508-4226.

About Dr. Timmermans

Dr. Drew Timmermans, ND, RMSK

Dr. Drew Timmermans, ND, RMSK, specializes in precision-guided orthobiologic injections for chronic musculoskeletal pain. His approach centers on thorough 2-hour evaluations where the hands-on physical exam, not imaging, is the primary diagnostic tool. He holds the RMSK credential (Registered in Musculoskeletal Sonography), certifying advanced competency in diagnostic and interventional musculoskeletal ultrasound. He tracks patient outcomes using five validated, peer-reviewed functional instruments (KOOS-JR, HOOS-JR, ODI, NDI, QuickDASH) and is partnered with DataBiologics, a patient outcome registry. Regenerative Performance is located in Gilbert, AZ.