Commentary in italics by Topher

Background

Dextrose injection is reported to improve knee osteoarthritis (KOA)−related clinical outcomes, but its effect on articular cartilage is unknown. A chondrogenic effect of dextrose injection has been proposed.

This is an interesting proposition. As we know prolotherapy can help stimulate the healing of connective tissue (think ligaments and tendons) but when a full prolotherapy or PRP treatment is performed it includes an injection into the joint itself. If prolotherapy injections into the joint itself can help reduce knee pain and increase function then it stands to reason that there is a beneficial effect on the knee joint itself. How many friends or family members do you have that have gone to their doctor with knee pain and were told that they have a knee or knees that are “bone on bone” ? 

Objective

To assess biological and clinical effects of intra-articular hypertonic dextrose injections (prolotherapy) in painful KOA.

KOA is short for “knee osteoarthritis”.

Design

Case series with blinded arthroscopic evaluation before and after treatment.

“Arthroscopic” refers to an actual surgical procedure where a joint is examined with a small camera that is inserted into the joint. 

Setting

Physical medicine and day surgery practice.

Participants

Symptomatic KOA for at least 6 months, arthroscopy-confirmed medial compartment exposed subchondral bone, and temporary pain relief with intra-articular lidocaine injection.

Interesting qualities that each of the participants had: painful knee OA (osteoarthritis) when they were first examined. Then they had the knee examined with an ultrasound to confirm that they had exposed bone in the medial knee. This shows that the cartilage was worn away. 

A knee injection was then done with anesthetic to temporarily block the pain. If this was positive they underwent an arthroscopy with the knee joint examined and mapped out.   

Intervention

Four to 6 monthly 10-mL intra-articular injections with 12.5% dextrose.

These are the same injections I perform in my Sacramento clinic when I treat knee pain with prolotherapy.

Main Outcome Measures

Visual cartilage growth assessment of 9 standardized medial condyle zones in each of 6 participants by 3 arthroscopy readers masked to pre-/postinjection status (total 54 zones evaluated per reader); biopsy of a cartilage growth area posttreatment, evaluated using hematoxylin and eosin and Safranin-O stains, quantitative polarized light microscopy, and immunohistologic cartilage typing; self-reported knee specific quality of life using the Western Ontario McMaster University Osteoarthritis Index (WOMAC, 0-100 points).

Repeat arthroscopies and mapping was done after the prolotherapy injections. They were compared to the pre-treatment maps. 

Results

Six participants (1 female and 5 male) with median age of 71 years, WOMAC composite score of 57.5 points, and a 9-year pain duration received a median of 6 dextrose injections and follow-up arthroscopy at 7.75 months (range 4.5-9.5 months). In 19 of 54 zone comparisons, all 3 readers agreed that the posttreatment zone showed cartilage growth compared with the pretreatment zone. Biopsy specimens showed metabolically active cartilage with variable cellular organization, fiber parallelism, and cartilage typing patterns consistent with fibro- and hyaline-like cartilage. Compared with baseline status, the median WOMAC score improved 13 points (P = .013). Self-limited soreness after methylene blue instillation was noted.

Conclusions

Positive clinical and chondrogenic effects were seen after prolotherapy with hypertonic dextrose injection in participants with symptomatic grade IV KOA, suggesting disease-modifying effects and the need for confirmation in controlled studies. Minimally invasive arthroscopy (single-compartment, single-portal) enabled collection of robust intra-articular data.

Very interesting study showing the potential for regrowth of cartilage in knee osteoarthritis after serial prolotherapy injections. 

If knee pain is something that bothers you and limits your ability to play golf or tennis, run, go to the gym, do CrossFit, go hike or just live your life the way you want to live it please call our Sacramento clinic.