Retrospective Study Shows Prolotherapy is Effective in the Treatment of MRI-Documented Meniscal Tears and Degeneration

The Case for Utilizing Prolotherapy as First-Line Treatment for Meniscal Pathology: A Retrospective Study Shows Prolotherapy is Effective in the Treatment of MRI-Documented Meniscal Tears and Degeneration
Ross A. Hauser, MD, Hilary J. Phillips, and Havil S. Maddela

ABSTRACT
Meniscus injuries are a common cause of knee pain, accounting for one sixth of knee surgeries. Tears are the most common form of meniscal injuries, and have poor healing ability primarily because less than 25% of the menisci receive a direct blood supply. While surgical treatments have ranged from total to partial meniscectomy, meniscal repair and even meniscus transplantation, all have a high long-term failure rate with the recurrence of symptoms including pain, instability, locking (see loose bodies), and re-injury. The most serious of the longterm consequences is an acceleration of joint degeneration. This poor healing potential of meniscus tears and degeneration has led to the investigation of methods to stimulate biological meniscal repair.

Research has shown that damaged menisci lack the growth factors to heal. In vitro studies have found that growth factors, including platelet derived growth factor (PDGF), transforming growth factor (TGF), and others, augment menisci cell proliferation and collagen growth manifold. See The Regeneration of Articular Cartilage with Prolotherapy

Animal studies with these same growth factors have confirmed that meniscal tears and degeneration can be stimulated to repair with various growth factors or solutions that stimulate growth factor production. The injection technique whereby the proliferation of cells is stimulated via growth factor production is called Prolotherapy.

Prolotherapy solution can include dextrose, human growth hormone (HGH), platelet rich plasma, and others, all of which stimulate connective tissue cells to proliferate. A retrospective study was done involving 24 patients, representing 28 knees, whose primary knee complaints were due to meniscal pathology documented by MRI. The average number of Prolotherapy visits was six and the patients were followed on average 18 months after their last Prolotherapy visit.

Prolotherapy caused a statistically significant decline in the patients’ knee pain and stiffness. Starting and ending knee pain declined from 7.2 to 1.6, while stiffness went from 6.0 to 1.8. Prolotherapy caused large improvements in other clinically relevant areas such as range of motion, crepitation, exercise, and walking ability. Patients stated that the response to Prolotherapy met their expectations in 27 out of the 28 knees (96%)

Only one out of the 28 patients ended up getting surgery after Prolotherapy. Based on the results of this study, Prolotherapy appears to be an effective treatment for meniscal pathology. While this is only a pilot study, the results are so overwhelmingly positive that it warrants using Prolotherapy as first-line therapy for meniscal pathology including meniscal tears and degeneration.

Epidemiology of Meniscal Injuries
Knee injuries are a common concern resulting in over 1 million surgeries performed to the knee in the United States every year.1-3 According to the National Athletic Trainers’ Association, knee injuries account for 10% to 19% of high school sports injuries and 60.3% of all high school athletic-related surgeries.4 Similar studies of collegiate sports have shown that knee injuries make up 7% to 54% of athletic injuries, varying by the nature of the sport.5-9 The leading injuries to the knee, in both adults and children alike, are primarily patellofemoral derangements or ligament strains and tears.10-12

Secondary to these injuries are meniscal tears, which have generated particular interest in both the young and elderly population as studies over the past several decades have revealed a rise in both degenerative and traumatic meniscal injuries. Meniscal tears occur as early as childhood, where they serve as the leading cause of pediatric arthroscopy, and increase with age and activity.13,14 An estimated one sixth of knee surgeries are performed for lesions of the meniscus, and it is likely that many more remain untreated every year.15,16 In one study of cadaver knees, untreated meniscal lesions were found in 34% of the autopsied subjects.17 A significant percentage of meniscal injuries result from athletic injury. On a professional level, meniscal tears accounted for 0.7% of all injuries sustained in the National Basketball Association, totaling 3,819 days missed by NBA athletes over a 10 year span.18

In college sports, studies conducted over a 16 year span by the National Collegiate Athletic Association Injury Surveillance System found internal knee derangement was second only to ankle sprains in both men’s and women’s college basketball and men’s and women’s soccer.5-8 An independent study of college football had equally devastating statistics, reporting injuries to the meniscus in roughly one in five elite college football athletes.9 With participation in college sports on the rise, the number of meniscal injuries and subsequent surgeries are consequently rising at an alarming rate.19 Although athletes appear to have the highest instance of injury, meniscus injuries can happen anywhere, regardless of a person’s level of activity. A research study conducted in Greece showed that meniscal tears developed equally from traumatic and non-traumatic causes with 72% of all meniscal tears occurring during normal activities of daily living.20

Anatomy and Function
The menisci (plural of meniscus) are a pair of C-shaped fibrocartilages which lie between the femur and tibia in each knee, extending peripherally along each medial and lateral aspect of the knee. (See Figure 1.) The anatomy of both menisci is essentially the same, with the only exception being that the medial meniscus is slightly more circular than its hemispherical lateral counterpart. Each meniscus has a flat underside to match the smooth top of the tibial surface, and a concave superior shape to provide congruency with the convex femoral condyle. Anterior and posterior horns from each meniscus then attach to the tibia to hold them in place. The meniscus is comprised of approximately 70% water and 30% organic matter. This organic matter is primarily a fibrous collagen matrix consisting of type I collagen, fibrochondrocytes, Proteoglycans, and a small amount of dry noncollagenous matter.21,27 There has been a great deal of speculation and research dedicated to what exact function the meniscus serves, but today there is general consensus that the menisci provide stability in the joint, nutrition and lubrication to articular cartilage, and shock absorption during movement.21-25 The menisci provide stability to the knee joint by both restricting motion and providing a contour surface for tibiofemoral bone tracking. The function of stability is shared with several ligaments which work together to prevent overextension of any motion. The transverse ligament connects the two menisci in the front of each knee and prevents them from being pushed outside of the joint at any point. Hypermobility is avoided through the connection of the medial collateral ligament (MCL) to the medial tibial condyle, femoral condyle, and medial meniscus, and the connection of the lateral collateral ligaments (LCL) to the lateral femoral epicondyle and the head of the fibula; these ligaments provide tension and limit motion during full flexion and extension, respectively. The anterior and posterior meniscofemoral ligaments form an attachment between the lateral meniscus and the femur and remain taut during complete flexion. Lastly, the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) are responsible for preventing too much backward or forward motion of the tibia.23,24 The menisci also provide shock absorption and stability by equally distributing weight across the joint.