Definition and Overview
Prolotherapy (proliferative therapy) is a regenerative injection treatment in which an irritant solution such as hypertonic dextrose is precisely injected around damaged ligaments, tendons, joint capsules, or entheses to intentionally induce a localized inflammatory response, thereby promoting connective tissue regeneration and structural reinforcement.
The name "prolotherapy" is a combination of "proliferation" and "therapy," reflecting the principle of inducing tissue regeneration and proliferation. In clinical use since the 1950s, it is currently utilized as a non-surgical alternative for chronic musculoskeletal pain.
Mechanism of Action
The primary mechanisms of action of prolotherapy are understood as follows.
When hypertonic dextrose solution is injected into tissue, osmotic differentials cause micro-damage to cells. In response to this damage, platelets aggregate and growth factor secretion is stimulated.
Key growth factors released include platelet-derived growth factor (PDGF), transforming growth factor-beta (TGF-beta), and insulin-like growth factor-1 (IGF-1), which activate fibroblasts to promote collagen synthesis and tissue regeneration.
Proposed neural mechanisms include increased proprioceptor density in ligaments and tendons, as well as reduced sensitization of pain-mediating nerve fibers. However, the complete mechanism has not yet been fully elucidated, and further research is ongoing.
Indications
The primary indications for prolotherapy include the following.
Chronic low back pain is indicated when accompanied by ligament laxity or tendon-origin pain. Studies have reported significant pain reduction over 3–6 months [1].
For knee osteoarthritis, a randomized controlled trial by Rabago et al. (2013) demonstrated that hypertonic dextrose injection showed significant improvement in pain scores and function compared to saline injection and home exercise [2].
For ligament laxity, prolotherapy is applied to chronic laxity of the anterior cruciate ligament (ACL), sacroiliac joint ligaments, ankle ligaments, and others [4].
Clinical applications also include tendinopathy, cervical pain, sacroiliac joint pain, medial epicondylitis (golfer's elbow), and Achilles tendinopathy.
Procedure
The procedure is performed under aseptic conditions after accurately identifying the target site using image guidance (ultrasound or fluoroscopy) or surface anatomy landmarks.
The injection solution typically consists of 15–25% dextrose mixed with 1% lidocaine, with concentration and volume adjusted according to the treatment site. The standard approach involves multiple small-volume injections at several ligament and enthesis points in a single session.
Treatment intervals are typically 2–4 weeks, for a total of 3–6 sessions, adjusted according to patient response. Corticosteroids and NSAIDs should be avoided immediately after the procedure, as they may impair the therapeutic response.
Efficacy and Evidence
For chronic low back pain, a Cochrane systematic review by Dagenais et al. (2007) confirmed that dextrose-pyrophosphate combination solution injection was effective for pain improvement, although additional high-quality studies were deemed necessary for dextrose-only prolotherapy [1].
An RCT by Yelland et al. (2004) comparing prolotherapy, saline injection, and exercise therapy found that all groups showed pain reduction over time, with limited between-group differences, resulting in interpretive limitations regarding the mechanism [3].
For knee osteoarthritis, a randomized double-blind study by Reeves and Hassanein (2000) demonstrated significant pain and functional improvement in the dextrose injection group compared to the saline group [4]. This result was replicated in a subsequent RCT by Rabago et al. (2013) [2].
Overall, evidence supporting the efficacy of prolotherapy is accumulating; however, challenges in establishing standardized control groups and study heterogeneity necessitate additional high-quality, large-scale RCTs.
Precautions and Prognosis
Contraindications include infection at the injection site, allergy to dextrose or lidocaine, bleeding disorders or concurrent anticoagulant use, and immunocompromised states (including poorly controlled diabetes).
Post-procedure precautions include avoiding strenuous activity at the treatment site for 1–3 days, limiting NSAID use (which may impair the therapeutic response), and recognizing that localized warmth and swelling at the injection site within 1–2 days represent a normal inflammatory response.
Reported adverse effects include temporary increased pain at the injection site, hematoma, and infection (rare). Accurate anatomical needle placement is the key to preventing complications.
Treatment responses vary considerably among individuals, and outcomes may differ depending on disease severity, duration of symptoms, and overall health status. Some studies suggest that concurrent conservative treatments (exercise therapy, physical therapy) may enhance outcomes.