I believe the future of soft tissue repair is really biologically based. If we can manipulate and accelerate the biology of healing and augment the mechanical strength of the tissue by inducing growth factors and inciting the inflammatory cascade, we are truly making a difference in the future structure of the tissue that is injured. Encouraging the tissue to remodel and lay down type I collagen is the goal here as long-term chronic “inflammation” results in a loss of function, production of other non-desirable collagen types and sometimes complete fibrosis. Here the physician should consider the use of different injection therapies that induce growth factors and resurge the inflammatory cascade to redirect tissue repair back into the proper direction (see “An Overview Of The Stages Of Wound Healing” at right)
Choosing From The Various Injection Therapies
Available injection therapies include prolotherapy, platelet rich plasma (PRP) injections and needling injections. All of these injection therapies promote the inflammatory cascade via infusion of growth factors, which will eventually induce new type I collagen production. When one introduces a needle into any tissue, it produces the “needle effect” or “puncture phenomenon,” creating local inflammation at the injection site. It causes irritation of nerve endings, gait control reactions and often influences distant components of segmental nerves by reflex stimulation. Inserting a needle into tissue also releases opioid peptides (endorphins and enkephalins) in the nervous system.
Prolotherapy. Prolotherapy rehabilitates an incompetent structure, such as a ligament or tendon, by inducing the proliferation of new cells. The solutions that are typically in use are a mix of dextrose solution, lidocaine and Sarapin (High Chemical Company). Dextrose is a corn extract, which is more hypertonic than blood and will not affect blood sugar issues in patients with diabetes. Sarapin is an extract of the pitcher plant, has no known side effects and accelerates the cellular particles into the tissue. Lidocaine gives immediate relief and confirms the location of the problem. If a patient is corn intolerant, one can use other agents, such as sodium morrhuate, an extract of cod liver oil. Zinc sulfate or a dextrose-glycerin-phenol solution called P2G are other options.
Prolotherapy is effective on any chronically damaged tissues. Physicians can administer the injections every four weeks with a total of three to six visits. Injections occur at the site of injury or chronic pain with the goal of strengthening the tissues by inciting the inflammation response and encouraging the collagen type 1 to form. Hackett’s original study on prolotherapy showed increases in strength and proliferation of the tissues at the fibro-osseous junctions in the rabbits that he sacrificed.1 Holistic physicians have used this technique since approximately the 1950s.
Platelet rich plasma. The PRP injections utilize a completely autologous system. After extraction of a small amount of the patient’s own blood and with a centrifuge process, the blood spins down, producing a fibrin matrix scaffold product. One can then inject this platelet rich fibrin matrix into the patient’s injured soft tissues.
Depending on the system used, the platelets and the numerous growth factors they induce will persist for varying days at the tissue site. This will incite the introduction of the proper cascade of events to occur to produce new healthy collagen. With this technique, one can use the protocol for injection or if the product goes through the centrifuge twice, physicians can suture the product into a wound, around a surgically repaired tendon or soft tissue structure. Many podiatric and orthopedic physicians are knowledgeable of this protocol, but may be limited in using the technique due to insurance reimbursement issues. Physicians can use PRP more than once in a particular area but cost may limit the exposure or usage for many patients.