Orthobiologic injections
Platelet-rich plasma (PRP)
Platelet-rich plasma is prepared by drawing a small volume of a patient’s own blood and spinning it in a centrifuge to separate and concentrate the platelet fraction. Platelets carry growth factors involved in tissue repair, and the concentrate is injected into an injured tendon, ligament or joint with the aim of influencing that repair process. It is an autologous treatment — the material comes from the person receiving it — and contains no corticosteroid.
How it works
The rationale rests on a distinction that is easy to miss: most long-standing tendon problems are not inflamed. They are degenerative — a repair process that began and then stalled.
-
What platelets carry
Platelets are best known for clotting, but they also transport the signalling proteins that begin tissue repair — platelet-derived growth factor, transforming growth factor beta, vascular endothelial growth factor and others. When tissue is injured, platelets arriving at the site release these, and that release is what starts the repair sequence.
-
Why concentration is the point
A PRP preparation holds platelets at several times their concentration in whole blood, in a small volume placed directly at the target. The intention is to deliver a denser signal to that tissue than the circulation on its own would ever bring to it.
-
Why tendon and ligament in particular
Tendon and ligament have a sparse blood supply compared with muscle or skin, which is part of why they heal slowly and often incompletely. Placing the signalling proteins directly into the tissue is an attempt to supply what the blood supply does not.
-
Provoking a response rather than suppressing one
Degenerative tendon tissue is disorganised rather than swollen, which is why anti-inflammatory treatment so often disappoints in it. PRP works the other way round: it deliberately provokes a controlled inflammatory response in order to restart a repair process that had stopped.
-
Why preparations differ
Systems vary in how far they concentrate the platelets and in whether they retain white blood cells. Leukocyte-rich preparations provoke a stronger inflammatory response and are generally favoured for tendon; leukocyte-poor preparations are usually preferred inside a joint. Which is used is a considered choice rather than a matter of what the machine produces.
The repair sequence it is aiming at
- Inflammatory phase — the first few days The injection provokes the response an acute injury would. Platelets release their growth factors and the cells that build tissue are recruited to the site. The soreness over these days is that phase happening, which is why it is expected rather than a sign of trouble.
- Proliferative phase — roughly weeks two to six Fibroblasts lay down new collagen and small blood vessels grow into the area. The new tissue is disorganised at this stage and not yet strong, which is why loading through this period is graded deliberately rather than avoided or rushed.
- Remodelling — three months and beyond Collagen reorganises along the lines of the force applied to it. What the tissue is asked to do during this phase is largely what determines how strong it ends up, which is the reason PRP is given alongside a rehabilitation programme rather than instead of one.
What the procedure involves
PRP is an outpatient procedure, usually completed in a single visit of under an hour.
-
Blood draw
A small volume of blood is taken from a vein in the arm, comparable to a routine blood test.
-
Centrifugation
The sample is spun to separate its components and concentrate the platelets. Nothing is added and no donor material is involved.
-
Injection under image guidance
The concentrate is injected into the target tissue. Ultrasound or fluoroscopic guidance is used to place it accurately, as many targets are small and cannot be located reliably by surface landmarks alone.
-
Aftercare
Instructions usually cover a short period of relative rest followed by a graded return to loading, often alongside a rehabilitation programme.
What to expect afterwards
PRP is prepared from the patient’s own blood, so it carries none of the risks that come with donor material or transfusion.
-
Post-injection soreness
An increase in pain at the site for several days is common and expected, because the treatment is intended to provoke a biological response. It settles as the first phase of repair passes.
-
Coverage
PRP is generally considered investigational by insurers and is usually not covered, which is a practical consideration when weighing it against alternatives.
Common questions
How does PRP differ from a steroid injection?
A corticosteroid injection suppresses inflammation and often relieves pain quickly, but repeated use can weaken tendon tissue. PRP contains no steroid and aims to influence repair rather than suppress inflammation; any benefit tends to develop over weeks rather than days.
Why does it get sore before it gets better?
Because the first phase of the response is meant to be inflammatory. The injection is provoking the beginning of a repair sequence, and the soreness over the first few days is that phase taking place. It settles as the process moves on.
How long before any effect is noticed?
Where PRP helps, improvement is typically gradual over several weeks to a few months. It is not a treatment that produces immediate relief, and soreness in the first days afterwards is normal.
Why does image guidance matter?
Targets such as a tendon insertion can be a few millimetres across. Injections placed by palpation alone are less accurate, and medication delivered into surrounding tissue rather than the intended target is a different treatment from the one planned.
Is more than one injection needed?
Protocols vary, and some conditions are treated with a series. The number is decided case by case, and there is no single accepted standard across the literature.
Is the evidence settled?
No. PRP is an area of active research with heterogeneous study designs and preparation methods. It is reasonable to discuss what is and is not known for a specific condition before deciding.
General reference information, and not advice about your own case. It may not reflect the most recent guidance or what is offered on a given day — call (201) 408-5151 to check.
Schedule an appointment
Dr. Yoo Rehab Clinic welcomes new patients from across Northern New Jersey and New York City, including Englewood, Teaneck, Fort Lee, Palisades Park and Ridgefield. Call today to learn more about insurance, scheduling, and how we can help.
