Biologic Injections for Joint and Tendon Pain

PRP, BMAC and Protein Concentrate for knee, hip and shoulder arthritis, rotator cuff and tendon injuries. What they are, who they help, and where the science actually stands.

Biologic injections are one of the most discussed topics in orthopedic medicine. Patients read about them online, see them advertised at wellness clinics, and ask about them in growing numbers. The problem is that the marketing has run well ahead of the explanation.

What follows is a plain-language account of the three options we use, Platelet-Rich Plasma, Bone Marrow Aspirate Concentrate, and Protein Concentrate, plus two we do not offer and why.

These treatments use your body's own biology. The goal is to deliver a concentrated dose of your own repair signals exactly where damaged tissue needs them most.

On this page

1. Platelet-Rich Plasma (PRP)

2. Bone Marrow Aspirate Concentrate (BMAC)

3. Protein Concentrate (PC) — not yet open for scheduling

4. Other Options You May Hear About

5. Aftercare & When to Call

 

Platelet-Rich Plasma (PRP)

The most widely studied orthobiologic in clinical use.

PRP is made entirely from your own blood. Platelets are best known for clotting, but they carry something more important for healing: alpha granules packed with growth factors. Activated at the injection site, these proteins signal tissue to repair, reduce inflammation, and recruit healing cells to the area. PRP concentrates those signals and delivers them precisely where they are needed.

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The procedure, about 45 minutes in-office

A blood draw of 60 mL per joint is taken from your arm, much like a routine lab draw. The blood is spun in a centrifuge for roughly 10 minutes, separating it into layers: red cells at the bottom, platelet-poor plasma at the top, and the platelet-rich layer between them. That layer is extracted and prepared for injection. We target a therapeutic dose of 5 to 10 billion platelets, the range the clinical literature supports for meaningful effect.

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Not all PRP is the same

This is a detail most patients never hear, and it changes what you get.

LR-PRP (leukocyte-rich) contains white blood cells alongside the platelets. We use it for tendons: rotator cuff, Achilles, patellar, gluteal tendons, tennis elbow. Tendon healing is driven by an inflammatory response. White cells support that process and clear damaged collagen so new tissue can lay down.

LP-PRP (leukocyte-poor) has the white blood cells removed during processing. We use it for joints: knee, hip, and shoulder osteoarthritis. The synovial lining is sensitive. White cells inside a joint can amplify inflammation rather than resolve it, so a cleaner preparation protects the joint.

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Who tends to do well

• Mild to moderate knee osteoarthritis

• Rotator cuff tendinopathy, non-surgical

• Gluteal tendinopathy

• Lateral epicondylitis (tennis elbow)

• Patellar or Achilles tendinopathy

• No response to prior cortisone

• Wanting to delay or avoid surgery

 

Who may not be a good fit

• End-stage joint disease, bone on bone

• Active infection at the injection site

• Platelet disorders or blood thinners

• Active inflammatory arthritis

• Expectation of a cure

 

Preparing for and recovering from PRP

Two days before. Increase your fluid intake for the full 48 hours beforehand. Well-hydrated veins make the draw easier and support a better yield from the centrifuge. Skip alcohol. Stop NSAIDs and fish oil 10-14 days ahead.

Days 1 to 3. Expect a flare. Soreness and swelling are normal and expected. Take acetaminophen for pain. Do not use NSAIDs or cortisone, and see the ice and heat guidance further down.

Days 4 to 14. Protect the response. Continue avoiding high-impact activity and all anti-inflammatory medications for two full weeks after injection. Walking and light range of motion are encouraged.

Weeks 3 to 6. Start loading the tissue. This is where physical therapy earns its keep. For tendon treatments, eccentric loading is the single most important component and should progress gradually. Resume activity as tolerated.

Weeks 10 to 24. Give it time. Many patients do not feel the full effect until somewhere between 10 and 12 weeks, and the response often keeps building past that. We reassess at three months and decide together whether a second injection makes sense.

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Bone Marrow Aspirate Concentrate (BMAC)

A signaling-cell-rich concentrate harvested from your own bone marrow.

BMAC is drawn from bone marrow, which holds a dense population of signaling cells, cytokines, and growth factors. Unlike PRP and Protein Concentrate, which are blood-based, BMAC comes from the marrow space. It suits complex joint pathology and cases where blood-based biologics have not produced a sufficient response.

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Why we no longer say "stem cell injection"

You may have seen BMAC advertised as a stem cell injection. We used that term as well, until the science caught up with the marketing. Early theory held that bone marrow contained enough mesenchymal stem cells to travel to damaged tissue and physically rebuild it. That proved to be an oversimplification. Cell concentrations in BMAC are lower than originally assumed, and those cells do not engraft and regenerate tissue the way the early narrative implied.

BMAC works through biological signaling, modulating inflammation and communicating with surrounding tissue. The effect is real. We simply describe it accurately.

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The procedure, about 75 minutes

The harvest site at the posterior iliac crest, the back of the pelvis, is numbed thoroughly with local anesthetic before anything else happens. This matters: the anesthetic is what keeps the harvest tolerable, and we take our time with it.

A specialized needle then draws 60 to 120 cc of bone marrow. Most patients describe a deep pressure sensation rather than sharp pain, lasting a few minutes. The marrow is concentrated in a centrifuge to isolate the signaling cells and growth factors, then injected into the target joint or tissue. The harvest site is bandaged before you leave and will be sore for several days independently of the joint itself.

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Who tends to do well

• Advanced osteoarthritis, not yet surgical

• Avascular necrosis, early to mid-stage

• Partial ligament or complex tendon tears

• Inadequate response to PRP or Protein Concentrate

• Complex, multi-tissue joint pathology

• Wanting the highest-concentration option

 

Who may not be a good fit

• Complete structural failure needing surgery

• Active infection, cancer, or blood disorders

• Long-term anticoagulation therapy

• Unable to tolerate the aspiration

• Severe systemic illness

 

Preparing for and recovering from BMAC

Two days before. Increase your fluid intake for the full 48 hours beforehand. Hydration makes the harvest and processing go more smoothly. Skip alcohol. Stop NSAIDs and fish oil 10-14 days ahead. Arrange a ride home.

Days 1 to 5. Two sites to manage. Soreness at both the injection site and the harvest site is expected. The harvest site may ache for three to five days. Acetaminophen for pain. No NSAIDs.

Days 6 to 14. Protect both sites. No high-impact activity, no anti-inflammatory medications, no cortisone. The signaling cascade is active and is disrupted by inflammation suppression.

Weeks 3 to 10. Gradual return and rehab. Physical therapy is typically introduced at weeks three to four. Where tendon is involved, eccentric loading is the priority. Most patients notice change between weeks four and eight.

Weeks 10 to 24. Give it time. BMAC has a slower onset than PRP or Protein Concentrate. Expect 10 to 12 weeks before judging it, and many patients keep improving through month six.

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Protein Concentrate (PC)

Availability. PRP and BMAC are available now. Protein Concentrate is not yet open for scheduling. We are including it here so that patients weighing their options understand the full range of biologic treatments and what is ahead. We will notify patients directly when scheduling opens.

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A higher-dose, more refined formulation from your own blood.

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Protein Concentrate starts where PRP does, with your own blood, and then goes a step further. After the platelet layer is separated, the remaining plasma is processed again to concentrate a different class of molecules: protease inhibitors and anti-inflammatory proteins rather than growth factors. Where PRP works largely by stimulating repair, Protein Concentrate works by blocking the enzymes and signals that drive cartilage breakdown in addition to working with the platelets.

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The procedure, about 60 minutes in-office

Protein Concentrate begins exactly as PRP does. Blood is drawn and spun, and the platelet-rich layer is separated out. Where a PRP procedure would stop there, this one continues. The plasma fraction that would otherwise be set aside is passed through specialized filtration that concentrates its protein content, including alpha-2 macroglobulin and interleukin-1 receptor antagonist protein (IRAP).

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These are not growth factors. They are inhibitors. Alpha-2 macroglobulin binds and clears the enzymes that break down cartilage, and IRAP blocks one of the primary inflammatory signals driving joint degeneration (IL-1). The result is a preparation aimed less at stimulating repair and more at interrupting the destructive cycle, which is why it suits more advanced joint disease.

 

Who would be a good candidate

• Moderate to advanced osteoarthritis

• Partial rotator cuff or labral tears

• Incomplete response to standard PRP

• Complex tendon pathology

• Higher-demand athletes and active workers

• Symptomatic gluteal tendinopathy

 

Who may not be a good fit

• Complete tendon ruptures needing surgery

• Active systemic infection or malignancy

• Severe "bone on bone" osteoarthritis with no cartilage left

• Platelet or clotting disorders

• Anticoagulant therapy, case by case

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Aftercare for Protein Concentrate follows the same principles described below. We will publish a full recovery timeline when scheduling opens.
 

Other Options You May Hear About

Biologics is a crowded and loosely regulated marketplace, and patients routinely arrive having read about treatments we do not offer. Two come up often enough to address directly, so you know what they are and where we stand before someone sells you one.

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Adipose-derived therapy (fat-based injections)

What it is. Fat tissue is a rich source of signaling cells and pericytes. Two preparations exist: microfragmented adipose tissue (MFAT), which breaks fat down mechanically through progressively finer filters, and stromal vascular fraction (SVF), which uses enzymatic digestion to separate the cellular portion from the fat itself.

How it is obtained. Through a mini-liposuction harvest, usually from the abdomen or flank, under local anesthetic. This is a more involved harvest than a blood draw and leaves a second surgical site.

The evidence. A randomized controlled trial comparing MFAT to PRP for knee osteoarthritis found the two equivalent at twelve months. The evidence is real but does not currently show adipose outperforming what we already offer.

Where we stand. We do not offer fat-derived injections. Given equivalent results in the head-to-head data, we are not persuaded that a liposuction harvest is justified when a blood draw delivers comparable outcomes. If the evidence shifts, so will our position.

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Umbilical, amniotic, and placental products

What it is. Products derived from donated birth tissue: umbilical cord, Wharton's jelly, amniotic fluid, and placental membrane. These are frequently marketed as stem cell injections and sold at a premium, often by sales representatives rather than physicians.

The problem. Independent laboratory testing has repeatedly found no viable stem cells in commercial amniotic and umbilical products after processing. The FDA has not approved any birth tissue product for orthopedic use and has issued warning letters to manufacturers marketing them for joint conditions. Infections have been documented from contaminated cord blood preparations.

Where we stand. We do not use them, and this is the one place in this guide where our position is a matter of conviction rather than a close call. We believe healing should come from your own tissue. Autologous treatments carry no risk of donor disease transmission and no immune rejection, and the products marketed as an alternative frequently do not contain what patients are told they contain. If someone offers you a stem cell injection from birth tissue for a joint problem, we would encourage you to ask hard questions.

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Aftercare: What Applies to All Three

These are guidelines, not rules. Protocols vary widely between practices, and a 2024 systematic review found no consensus on much of it: how long to hold NSAIDs, when to resume activity, whether to ice at all. What follows is our reasoning and our best judgment. If something here does not fit your life, tell us and we will work it out.

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Ice or heat? What the evidence actually shows

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Some clinics forbid ice entirely; others recommend it three times a day. No randomized trial in humans has compared ice, heat, or neither after a biologic injection, so every protocol you will read is reasoning from mechanism rather than outcome data. Here is how we think about it, and why. Talk with us about your own situation before treating any of it as fixed.

First 72 hours, we suggest skipping ice. The soreness you feel is the treatment working. Your platelets are releasing growth factors and recruiting repair cells, and that cascade depends on inflammation. Cooling the area suppresses the very signals we injected you to produce.

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For pain in that window, acetaminophen. Tylenol controls pain without touching the inflammatory pathway. Stay ahead of the soreness rather than chasing it. Do not use ibuprofen, naproxen, or any other NSAID.

After 72 hours, ice is reasonable for comfort. The critical signaling window has passed. Ice for 15 to 20 minutes as needed. Elevation and gentle movement help more than most patients expect.

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Heat, we generally advise waiting a week. Heat is often suggested online as the alternative to ice. We lean against it early, since no evidence supports heat after injection and driving more blood flow into a freshly injected joint tends to worsen swelling. If heat is what makes you comfortable, raise it with us first.

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At a glance, our general guidance

• No NSAIDs for 2 weeks

• No cortisone for 6 weeks

• No high impact for 2 weeks

• Skip ice for the first 72 hours

• Hold heat for the first week

• Tylenol as needed

• Walking, in moderation

 

When to call the office

• Fever above 101.5°F, especially with chills, or any fever beyond the first 24 hours

• Spreading redness, warmth, or drainage at the injection site or, for BMAC, the pelvic harvest site

• Pain that sharply worsens after improving. A flare that settles and then returns hard is worth a call

• Calf swelling, tenderness, or tightness, particularly after a lower-extremity injection. Call promptly

• New numbness, tingling, or weakness anywhere below or beyond the treated area

• Swelling that worsens after day five. The early flare should be settling by then, not building

 

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Regulatory status. PRP, Protein Concentrate, and BMAC are considered investigational by the FDA for most orthopedic indications. Prospective clinical trials and peer-reviewed literature support their use, but formal FDA approval has not been granted. These treatments are typically not covered by insurance and are offered on a cash-pay basis. Individual results vary.

Dr. Matthew Wichman, MD, FAAOS and Dr. Mark Wichman, MD, FAAOS. For educational purposes only. This does not constitute medical advice. Treatment decisions should be made in consultation with your physician.