ACL reconstruction surgery alternatives and regenerative treatment options
Ross A. Hauser, MD., Danielle R. Steilen-Matias, MMS, PA-C.
ACL reconstruction surgery alternatives and regenerative treatment options
Is ACL reconstruction surgical repair the right option for every patient? In this article, we review the latest medical research that can help the patient/athlete understand their ACL pre and post-surgery challenges. If you are reading this article you may be debating whether to have surgery or not or that you are on the waiting list to get surgery. One option for treatment we will explore is regenerative medicine, non-surgical treatment options, and the realistic assessment of whether or not this can help you.
People who get ACL reconstruction surgery can have excellent results. These are not the people we see in our office. We see the people for whom the promise of ACL reconstructive surgery did not offer the same excellent results. We see the people who have had an ACL reconstruction, ACL reconstruction with meniscus repair, and second or revision ACL surgery for a rupture of the “fixed” ACL. We see the people for whom ACL surgery was not the answer and they need help. Now they are exploring options to either get them back to sports or to try to avoid what they were told was the inevitable advancement of osteoarthritis.
We also see the people who have to decide should they have the surgery or not. These are people who debate whether or not the surgery will be worth it for them and the long rehabilitation it implies. These may be people who have an urgency to return to sport before academic eligibility expires or the people who do a physically demanding line of work and have to way surgery versus other options to keep them on the job.
- If you have a question about ACL surgery options – email us now.
For many people, the hardest part of their injury is the decision as to what to do about it and waiting for a surgery date. Many ask: “Is ACL reconstruction really necessary?” “Can I get by without an ACL?”
For the young athlete who has an aspiration for a college athletic career, seemingly there is no choice but surgery. For the high school sophomore who wants to play their senior year and finish their youth sports career on the field, there seems to be only one choice, surgery. But what about the older recreational athlete, what about the person who works at a physically demanding job? What about the older patient? Is ACL reconstruction really necessary?
Someone who is debating surgery or no surgery will come into our clinics and tell a story that sounds like this:
My MRI confirmed that I have a torn ACL and a meniscus tear. My surgeon wants me to try Physical Therapy first as she suggested people can live without an ACL and do so happily. If my knee felt unstable, not right, or caused me any functional problems and/or I had to alter my lifestyle, then the ACL reconstruction surgery should be performed and the meniscus should be dealt with.
The PT seemed to go very well, I was fitted with a large brace, had a three a week schedule of PT and felt really good. While I felt my leg getting stronger, I realized that my knee remained unstable. I was fitted for a “better brace.” Now here I am looking for a non-surgical answer to my knee instability of one exists. (A person like this is seeking stability treatment for the whole knee, this means an examination of all the existing ligaments and a plan to strengthen those – see below).
Surgery or no surgery? Let’s get to the research
For some people, you do not need ACL reconstruction surgery to return to play.
“Whether surgical or conservative treatment is more effective in allowing patients to return to physical activity after anterior cruciate ligament (ACL) injury is controversial.”
A paper published in December 2017 (1) weighed in on the ACL Surgery or Not Debate.
The doctors of this study noted: “Whether surgical or conservative treatment is more effective in allowing patients to return to physical activity after anterior cruciate ligament (ACL) injury is controversial. We sought to compare mid-term outcome measures between isolated ACL tear patients who underwent reconstruction followed by closed kinetic chain exercises and those who underwent neuromuscular training only.”
Okay so in this study, what was the outcome? No statistical difference was observed.
“No statistical difference was observed between the groups for any of the parameters evaluated, including assessment of subjective knee function, one-leg hop test, assessment of joint position sense, muscle strength, and the health profile.”
“Our data suggest that early surgical reconstruction may not be a prerequisite to returning to recreational physical activities after injury in patients with ACL tears.”
For some people, you do not need ACL reconstruction surgery to return to play. We do realize that this is a hot-button suggestion and that many people will point to professional athletes as proof of the need for an ACL reconstruction surgery. Please keep reading, there is so much more to discuss.
This research was built on a 2019 study cited below.
Is ACL reconstruction surgery a guarantee to return to play? Hardly
Research: “some athletes still fail to return to play”
Again, we point out that some people do great with ACL reconstruction surgery. These are, however, not the people we see in our offices.
Research from Brown University (2) presents the return to play reality:
- “Accelerated rehabilitation has made recovery from (ACL) surgery more predictable and shortened the timeline for return to play (from ACL reconstruction surgery). (However) Despite success with advancements in anterior cruciate ligament reconstructions, some athletes still fail to return to play.”
ACL reconstruction does provide remarkable short-term knee stability. Unfortunately, the stability doesn’t last because no matter how hard the surgeons try, they can not simulate exactly the same biology pre-injury. If a patient has a grade 3 ligament tear, and the patient deems the ACL necessary, surgery is indicated. The cadaver or tendon graft that is replacing the torn ligament, however, will not function long-term like the original ACL.
This situation does describe someone we would see in our office, the patient who had successful ACL reconstruction but their knee is “still not right.” Why does the knee not feel right?
This is a study from the Hospital of Special Surgery published in Current reviews in musculoskeletal medicine, September 2017 (3)
- “Recent research continues to demonstrate a relatively low rate of return to the previous level of play among athletes following (ACL Reconstruction) ACLR combined with a significant risk of injury to either the ipsi (same side) or the contralateral (other side) ACL.
- Recent research also demonstrates a growing use of a varied battery of assessments to determine readiness to return to sport as well as a lack of consensus on the ideal rehabilitation program, the criteria for clearance for return to play (both in time from surgery and functional milestones), and the nature of a conditioning program designed specifically for transitioning the cleared athlete back to competition.
- Due to the lack of consensus and consistency regarding rehabilitation protocols and criteria for clearance to play after ACLR, deficits in strength, neuromuscular control, and psychological readiness may exist in “cleared” athletes. These deficits may not only negatively impact sports performance but also raise the risk of re-injury.
- Problems that exist following ACLR cannot be solved by one professional; successful rehabilitation and return to play require a coordinated effort among the surgeon, physical therapist, athletic trainer, and fitness professional.”
People are in our office because they also want to explore non-surgical regenerative medicine. Here we may be able to address knee instability by examining and strengthening the weakened and damaged ligaments in the operated knee, and now, the knee weakened by compensating for the other side injury.
The long-term results from many studies demonstrate that untreated joint instability remains.
Doctors from the Hospital for Special Surgery and Cornell Medical Center Program in New York reported in the Orthopaedic Journal of Sports Medicine (4) of the over 23,000 pediatric patients who underwent ACL reconstruction:
- 8.2% had a subsequent ACL reconstruction and
- 14% had subsequent non-ACL knee surgery.
The median time lapse between the first and second surgeries were 1.4 and 1.6 years, respectively.
- It was noted that this may be a conservative number of patients who had repeat tears, as the data only included those who underwent a second surgery and not those who decided not to have the additional surgery.
Failure of primary ACL reconstruction can be attributed to:
This is pointed out by Italian researchers who in part blame the ACL failure on compromised ligaments and the meniscus of one or both knees. Published in the Sports Medicine and Arthroscopy Review, (5) here are the highlights of this research:
- The number of patients undergoing ACL revision surgery following the failure of anterior cruciate ligament reconstruction has increased.
- Failure of primary ACL reconstruction can be attributed to:
- technical errors,
- tunnel malposition (see below), untreated associated ligaments insufficiencies (see below), uncorrected lower limb malalignment, and graft fixation failures (the graph re-ruptured).
- new traumatic injuries
- biological failures, the new ACL failed, sometimes this is due to secondary deterioration in the other knee ligaments and meniscus.
- The relationship between meniscus damage and ACL failure is well understood. In new research from March 2017, doctors at the University of Toronto and the Cleveland Clinic showed clinically significant knee pain is more common following injuries to the medial meniscus and increased in patients who undergo early re-operation (revision surgery) after initial ACL reconstruction. These researchers suggest focus on repairing the medial meniscal tears sustained during ACL injury and a re-evaluation of the ACL surgery decision and timeline. (6)
- technical errors,
Lateral Posterior Tibial Slope
Lateral Posterior (backside) Tibial Slope (Angle of the top of the tibial or larger shin bone). The greater the angle or slant of the slope, the more likely anterior cruciate ligament reconstruction can fail.
Doctors have noted this. A December 2020 study from the University Hospital of Udine in Italy (7) recognized the role of the lateral posterior tibial slope as a potential risk factor for ACL reconstruction failure.
In this study, 47 patients who underwent second or revision ACL surgery were examined, in particular for Lateral Posterior Tibial Slope angles. What was found was that patients getting a second ACL reconstruction or revision surgery had significantly higher than the normal angles. Furthermore, females show a Lateral Posterior Tibial Slope significantly higher than males.
Conclusion: Doctors should examine the posterior lateral tibial slope as this higher slope can be a factor in a higher risk of ACL reconstruction failure.
“Despite common misconceptions to the contrary, research suggests that it is possible for an individual who suffers an ACL rupture to return to sport following management with rehabilitation alone”
Here is a 2019 study from the University of Oxford, Oxford and the Norwegian School of Sport Sciences.(8) the question being asked is “Do the outcomes of ACL rupture differ depending on management strategy?” Here are the learning points of this research:
- “There are a number of literature reviews comparing outcomes between individuals that are ACL-deficient or have had an ACL reconstruction surgery. It is important to note that most studies included in these reviews do not reflect best practices for nonoperative management of ACL rupture. For example, many of the nonoperatively managed patients in these studies received a diagnostic knee arthroscopy, some were advised to reduce activity levels, and rehabilitation was often not monitored, of low intensity or short duration, or included post-injury immobilization with a brace or cast.”
- Here is the learning point: “Despite this, these literature reviews report similar outcomes in ACL-deficient and ACL-reconstructed groups, including similar patient-reported outcomes, knee function, activity levels, quality of life and either no difference in radiographic osteoarthritis prevalence or a slightly increased prevalence following ACL reconstruction surgery.” We are going to see this again, the ACL reconstruction surgery increased the risk of osteoarthritis.
Here the researchers go further in the surgery or no-surgery debate.
“Despite common misconceptions to the contrary, research suggests that it is possible for an individual who suffers an ACL rupture to return to sport following management with rehabilitation alone. Several studies have found no difference in physical activity levels or return to sport rates between patients managed with ACL reconstruction surgery and those managed with rehabilitation.”
One in four patients will have THREE ACL surgeries on the same knee within 2 – 9 years
Continuing with this study, the researchers found: “Subsequent knee injury is common following ACL reconstruction; one-third of young individuals who undergo ACL reconstruction experience a second ACL tear and 27% experienced a third within 2–9 years after revision ACL reconstruction.”
Studies do not support that early ACL reconstruction prevents additional meniscus and cartilage injury
A common belief is that early ACLR prevents additional meniscus and cartilage injury. However, studies referenced to support this belief are typically retrospective reviews of surgical records, and show more severe joint injury in patients presenting for ACL reconstruction months or years after ACL rupture. . . On the other hand, evidence from prospective studies do not suggest management with rehabilitation as the first-line treatment results in more joint injury compared with management with early ACL reconstruction. . . In summary, best available evidence does not indicate that an individual is at greater risk of subsequent injury if they are managed with rehabilitation as the first-line treatment as opposed to ACL reconstruction.
A father tells the story of his daughter, a High School age softball player who had attracted college attention.
She tore her ACL
While this is a typical case history, the results may not be typical for everyone.
- Daughter was an avid, talented softball player. She suffered a skiing accident. At the time of the accident she was entering her High School senior year and was already examining offers from numerous colleges that were recruiting her for softball.
- The injury was an ACL injury. Two surgeons independently recommended ACL surgery as the only option. The rehab time would be about a year. She would lose her senior year of High School softball and the opportunity for college coaches to see her play.
- My wife started to do a lot of research as my daughter was devastated. In her research, my wife found Dr. Hauser. We took a flight out of New York to Caring Medical in Chicago. After the examination, our daughter was deemed to be an appropriate candidate for Prolotherapy treatment because she DID NOT have a full detachment of the ACL.
- After the one day treatment, she was sent home to New York with the instructions to RESUME activity. She was a catcher. She started catching immediately, no problems
- 4 weeks later the family returned to Chicago so the daughter could have another treatment.
- The story ends, with my daughter was able to play her senior year of High School at the catcher’s position. She entertained numerous college offers and accepted one to a Division 1 school. She played all 4 years and caught at least 70 games. During her college career she had a few Prolotherapy treatments to keep her knees strong. Seven years later she continues to play tennis and various sports.
Where is the role of knee instability in ACL repair? April 2018, 20 year follow up. Patients who had ACL reconstructive surgery more likely to have knee osteoarthritis than those who did not.
Doctors at Erasmus University Medical Center, Rotterdam, the Netherlands looked at fifty patients who had an ACL rupture from the 1990s. (9) Twenty-five patients were treated nonoperatively in 1992, consisting of structured rehabilitation and lifestyle adjustments. Twenty-five were surgical treated between 1994 and 1996 with ACL reconstruction featuring a patella tendon.
- The patients in the nonoperative group were drawn from those who responded well to 3 months of nonoperative treatment, whereas the patients in the operative group were drawn from those who had persistent instability after 3 months of nonoperative treatment and then sent to surgery.
- After 20 years, we found knee osteoarthritis in 80% of the operative group compared with 68% of the nonoperative group
- Although knee stability was better in the operative group, it did not result in better subjective and objective functional outcomes.
What this research suggests is that ACL reconstruction therapy may not provide the overall knee stability needed to prevent degenerative knee disease.
Joint instability is the missing diagnosis for athletes with ACL tears
It makes no sense that a person is subjected to multiple surgeries when it is obvious that joint instability is the cause of the problem. Joint instability is the missing diagnosis for athletes with ACL tears, and additional surgeries, no matter how sophisticated, are not the answer to the problem of joint instability. Pain, swelling, weakness, popping, grinding, and other symptoms associated with ACL tears can be addressed not with surgery, but with Prolotherapy.
We see many patients following ACL reconstruction surgery for Prolotherapy. They come in once their knee feels unstable and weak. As extensive independent research points out, the long-term results of initial ACL reconstruction demonstrate that untreated joint instability remains. After an examination, we recommend patients consider comprehensive Prolotherapy to treat the whole knee complex to help prevent the need for secondary surgery and to accelerate ACL reconstruction surgery recovery time. We discuss these points further below.
What are the excellent results in ACL reconstruction surgery? That is hard to say. The problem is that orthopedic surgeons’ perspectives of excellent results are different than athletes’ perspectives.
Patients expectations of excellent results in ACL reconstruction surgery not met
What are excellent results in ACL reconstruction surgery? That is hard to say. The problem is that orthopedic surgeons’ perspectives of excellent results are different than athletes’ perspectives.
As mentioned above, one of the main reasons for having the ACL surgery was the ability to return to sports. For many, this was not achieved.
Doctors from the Karolinska Institutet in Sweden found that patients saw no real choice between operative and non-operative treatment. Athletes perceived surgery as the only way to fully return to the pre-injury level of sports, and surgery was understood as the only way to become a completely restored “functional human being”.(10)
A major source of frustration to the patients was that the progress during the ACL rehabilitation process did not match their expectations, fear of re-injury became common.
- Complications and knee problems after the surgery were common.
- Patients reported pain including behind the knee, knee swelling, and knee popping
- Fear of re-injury was common.
- Other challenges were the commitment to staying with the ACL recovery timeline and the demands of physical therapy.
Some participants because the expectation of surgical success was not met decided not to return to their sports.
Revision ACL Reconstruction will likely fail AGAIN because of knee instability
In July 2020, a team of researchers from Germany’s leading sports medicine hospitals and universities published a study in the journal Knee surgery, sports traumatology, arthroscopy (11) to “carefully analyze the reasons for revision ACL revision failure to optimize the surgical revision technique and minimize the risk of recurrent re-rupture.”
The results of their research:
- “Failure after revision ACL reconstruction occurred in 14.5% of the cases followed.
- Preoperative medial knee instability was associated with failure; thus, patients had a 17 times greater risk of failure when medial knee instability was diagnosed.
- Preoperative medial knee instability is an underestimated risk factor for revision ACL reconstruction revision failure. “
So there is a question as to whether or not ACL reconstruction surgery is the best option. Here is a study on high school and college football players.
This question, whether or not ACL reconstruction is the best option, was further raised by researchers at Vanderbilt University Medical Center. Doctors there noted the lack of data regarding the effect of anterior cruciate ligament reconstruction on the ability of American high school and collegiate football players to return to play at the same level of competition as before their injury or to progress to play at the next level of competition.
- 43% of the players were able to return to play at the same self-described performance level.
- Approximately 27% felt they did not perform at a level attained before their ACL tear, and
- 30% were unable to return to play at all.
Although two-thirds of players reported some “other interest” contributing to their decision not to return, at both levels of competition, fear of reinjury or further damage was cited by approximately 50% of the players who did not return to play.”(12) Results that mimic those cited above.
Recently researchers in the United Kingdom put together a paper on best practices of when and type of ACL surgery to consider.
Here is a summary: The aim of ACL surgery is to restore functional stability to the ACL deficient knee. ACL reconstruction can be performed using a variety of different surgical techniques as well as different graft materials.
- The choice of whether to operate or not relies on many factors and is highly dependent on the patient’s degree of symptoms and requirements in terms of activity level and participation in pivoting sports.
- Many patients can become symptom-free following a course of physical therapy and rehabilitation.
Timing of any ACL reconstruction is also crucial, it is commonplace to allow the acutely injured knee to settle, giving time for resolution of swelling, restoration of range of motion, and recovery from concomitant ligament injuries. (I discussed this above in regard to meniscus injury).
Furthermore, a delayed reconstruction allows patients to try conservative therapy to see if surgery is indicated. (This is discussed at length below)
The three categories of commonly used grafts are:
- autograft, usually consist of either hamstrings tendons or Bone-patella tendon-bone (BPTB).
- allograft, Allografts are varied but can consist of tibialis posterior tendon, Achilles tendon, tibialis anterior tendon, BPTB, and peroneus longus tendon.
- and Synthetic graft. Synthetic grafts have been developed over the years and are currently on their “third-generation” but have encountered considerable problems in the past
The surgical technique used during ACL reconstruction varies widely. Different techniques include arthroscopic vs open surgery, intra vs extra-articular reconstruction, femoral tunnel placement, number of graft strands, single vs double bundle, and fixation method. (13)
Complete or a partial ACL tear, is ACL surgery is necessary? Some patients exhibit little or no symptoms when they play low-demanding sports or activities.
Generally, with a documented complete rupture, the patient has a choice of reconstruction surgery or non-surgical options. The non-surgical options would include first: A realistic assessment of future activities on an ACL-deficient knee. Some patients exhibit little or no symptoms when they play low-demanding sports or activities.
Here are the arguments for operating on a partial ACL tear:
Research from a combined team at Rush University Medical Center, Columbia University Medical Center, and the Hospital for Special Surgery:
- The optimal treatment for a partial anterior cruciate ligament (ACL) tear continues to be a subject of considerable debate.
- A question remains whether it is advantageous to preserve the ACL remnant and augment it with a graft, or get rid of it and start all over. Clinical outcomes of ACL preserving surgery are promising. An increasingly large body of scientific evidence suggests that augmenting the intact bundle is beneficial in terms of vascularity, proprioception, and kinematics. (14)
This is what doctors at Oxford University asked: They suggest that patients should always take caution when any type of joint surgery is recommended, and reconstruction of the anterior cruciate ligament (ACL) is no different. It is widely known that many patients who undergo ACL reconstruction experience a chronic “giving way” feeling after the surgery and some encounter a re-rupture of the tendon. (15)
When do conservatively treated partial ACL tears progress to full blown ruptures?
A 2019 study in the Orthopaedic journal of sports medicine (16) assessed the incidence and risk factors for the progression of partial ACL tears to complete ruptures after nonoperative treatment in active patients younger than 30 years old. Here are the observations and learning points of this study:
- “The most important finding of the current study was that, in young active patients with partial ACL tears treated nonoperatively, 39% progressed to a complete tear at a mean of 43 months after the first injury. (Patients under 20 years old) and participation in pivoting contact sports were significant predictive factors for failure of conservative treatment, that is, progression to a complete ACL tear. Meniscal lesions were found in 50% of cases that progressed to a complete ACL tear.”
The initial finding is that about four out 10 ten younger patients with a partial ACL tear would eventually see that tear progress to a full rupture on average about 3.5 years after the partial tear diagnosis.
Patients under 20 who participated in pivoting contact sports (soccer, basketball) were at higher risk and when they ruptured their ACL, meniscus damage was discovered that occurred previous to the rupture injury or was part of the rupture impact.
Returning to the research:
- “The diagnosis of a partial ACL tear remains controversial because there is no single “gold-standard” method, but rather, the diagnosis tends to rely on a combination of findings.”
- “(Studies) have suggested that partial tears of the ACL are functionally equivalent to complete tears and that nonoperative management generates poor results. Many authors have reported ACL deficiency rates of 14% to 56% after the nonoperative management of partial tears.”
- “Nonoperative treatment has its particular indications and reasonable results, but the typical patient profile has changed. Patient expectations of long-term sports participation have grown exponentially in tandem with increased longevity. In addition, patients are increasingly aware of how much time they will be out of work or away from their sport and how these time periods may differ between nonoperative and operative approaches.”
In this next section we will discuss conservative, non-surgical treatments not discussed in routine studies of ACL conservative care treatment. We will also revisit the partial vs. full rupture ACL tear and its accurate diagnosis and assessment.
Biomaterials Prolotherapy, PRP and stem cells in partial ACL tears
When discussing non-surgical applications of regenerative medicine such as stem cell therapy, Platelet-rich Plasma therapy, or Prolotherapy, discussions must be tempered with the realistic indications and outcomes that may be expected from these treatments.
- These regenerative medicine injections cannot regrow an ACL from nothing. If there is complete disintegration of the ligament, one cannot be regrown. The goals of these treatments are to help with a partial tear or overstretched ACLs. These treatments can restore strength and function to this type of ACL damage in many patients.
- Further, these treatments are designed to strengthen the entire knee capsule. All the ligaments should be treated to help the partial or stretched ACL heal, or if ACL reconstruction or more ACL reconstruction surgeries are declined by the patient, strengthen the knee capsule may help prevent knee instability and a more rapid degenerative arthritis from developing.
What is Prolotherapy and where is the research? Please visit our Prolotherapy research page for extensive and detailed information.
Prolotherapy is a “new” old treatment that has been utilized in clinical practices for over 80 years. Standardized and reviewed in clinical application by Dr. George Hackett in the 1950s, Prolotherapy has been shown to be an effective treatment in patients who suffer from joint instability due to ligament damage and overuse and related musculoskeletal and osteoarthritis. Prolotherapy’s popularity as a treatment for chronic pain has intensified over the past two decades among both physicians and patients as clinical and anecdotal observations have proved in many cases its reliance as a non-surgical option for joint and back pain.
- Prolotherapy is a nonsurgical regenerative injection technique that introduces small amounts of an irritant solution to the site of painful and degenerated tendon insertions (entheses), joints, ligaments, and in adjacent joint spaces during several treatment sessions to promote the growth of normal cells and tissues.
Irritant solutions most often contain dextrose (d-glucose), a natural form of glucose normally found in the body.
In January 2017, doctors writing in the Orthopedic Journal of Sports Medicine wrote of the controversies surrounding the repair of partial ACL tears. One of the controversies was reconstructive surgery. In this study, the researchers found that biologically augmented ACL-repair techniques (PRP and stem cells) improve healing and outcomes of both the native ACL (non-surgery) and the reconstructed graft tissue (surgery). (17)
In 2003, K. Dean Reeves, MD published in the journal Alternative Therapies in Health and Medicine (18) these findings:
- 16 knees with machine measured ACL laxity were injected bimonthly with 10-25% dextrose solution (Prolotherapy) for 1 year and then an average of 4 times yearly thereafter until 3-year follow-up.
- Summary: Using simple dextrose injection into 16 knees with a loose ACL ligament,
- 10/16 knees were no longer loose by machine measurement at the time of follow-up, and symptoms were improved.
- A symptom of osteoarthritis improved even in those who still tested loose.
- At the 3-year follow-up pain with walking had improved by 43%, subjective swelling improved 63%, flexion range of motion improved by 10.5 degrees, and machine measure of ACL ligament looseness improved by 71%.
How we examine for knee instability under ultrasound. Here we discuss the meniscus which is commonly injured in ACL tears.
The realities of non-surgical ACL regeneration
Stem Cell Therapy and Prolotherapy – Non-surgical ACL reconstruction?
Stem Cell Therapy involves direct bone marrow aspiration (or also concentrated) to get the stem cells to the site of the injury. We use bone marrow stem cells in conjunction with other Prolotherapy solutions to treat large articular defects in the meniscus areas. Typically, patients are seen every two months. Most patients need 3-6 visits. The good news is during the time of healing, the patient can exercise and start getting back into great shape.
Doctors at the Department of Trauma Surgery and Sports Injuries, University Hospital of Salzburg wrote in the Archives of Orthopaedic and Trauma Surgery:
“The ACL has the potential to heal upon intensive non-surgical rehabilitation procedures. Several biological factors influence this healing process as local intraligamentous cytokines (messengers that call for more inflammation (healing)) and mainly cell repair mechanisms controlled by stem cells or progenitor (creator) cells. Understanding the mechanisms of this regeneration process and the cells involved may pave the way for novel, less invasive and biology-based strategies for ACL repair.”(19)
In 2015, doctors in China excitedly published research in the Chinese Journal of Reparative and Reconstructive Surgery which said: “Enormous progress has been made in tissue-engineered ligament for repair and regeneration of ACL. With the development of biochemistry and scaffold materials, the tissue-engineered ligament will be used in clinic in the near future.”(20)
This research suggests that one day doctors will be able to grow a new ACL in the laboratory and implant it into a knee. That is fantastic news for the people of the future but what about today? Is there a way today to non-surgically repair a damaged ACL? Do you even need to replace the ACL?
Another team of Chinese researchers writing in the medical journal International Orthopaedics noted that the ACL has certain self-healing abilities after acute injury. These self-healing abilities have to do with stem cells (for a detailed discussion on how stem cells work please see my article on stem cell therapy). The Chinese team suggested that leaving behind part of the ruptured ACL remnant would release native stem cells into the new graft and augment healing. In addition, taking stem cells from the remnant ACL may be a potential source of seeding cells for ligament regeneration. (21)
This research found agreement in the work of Korean doctors who wrote in the medical journal Current stem cell research and therapy of recent developments in mesenchymal stem cell (MSC)-based approaches for enhancing healing after ACL injuries. They suggest that stem cells are a promising treatment options for enhancing biologic healing of ACL grafts and restoring the functional properties to the levels of the native ACL, and ultimately improving clinical outcomes. (22)
What this research suggests is stem cell augmentation for the ACL graft to prevent ACL complications.
The complexity of an ACL tear – Is it full? Partial? Can it regenerate on its own in the proper circumstance?
In 2009, Prolotherapy doctors led by Walter Grote MD published a case history of an 18-year old female patient who returned to sports after a high-grade partial (possibly complete) ACL rupture.
This case report, published in the medical journal International musculoskeletal medicine, documented the successful non-surgical repair of an MRI-confirmed high grade or total ACL tear in an 18-year-old female with knee laxity and instability using prolotherapy and at-home exercise. After treatment, the patient regained full knee function, resumed normal activity, and returned to recreational sport. Post-treatment MRI revealed a healing chronic ACL tear. These findings are notable given that surgical ACL reconstruction is the conventional treatment for ACL tears with such clinical presentation.
As exciting as this sounds, Dr. Grote and colleagues noted that there were too many factors in this ACL healing to confirm it was caused by Prolotherapy treatment alone. Listen carefully to what this case history presented:
Was the MRI of a complete ACL rupture even accurate?
- “While MRI is the diagnostic imaging technique of choice, it is not perfect. The tear may have therefore have been near-complete, or the severed ends of the ligament may have been in close enough approximation to facilitate natural healing.”
- The inaccuracy of MRI is well documented, in this case, the study could not be relied on to give an accurate reading. Please see my article on the MRI accuracy for determining the need for surgery. In this study, while MRI suggested a complete rupture, it may not have been a complete rupture.
The conclusion: The limitations above prevent a categorical conclusion that prolotherapy alone contributed to or restored pain-free function and improved the appearance of the MRI. However, the facts of this case and the context provided by prior clinical trials suggest that prolotherapy at least augmented the healing a high grade or total ACL tear. These findings further suggest that prolotherapy may be an alternative treatment to surgery for carefully selected patients and should be assessed as a treatment of ligamentous tears, especially in patients who are unwilling or unable to undergo surgical intervention.” (23)
So what to do with an ACL tear?
We believe the best treatment for grade 1 or grade 2 tear is Prolotherapy. If someone has a complete ACL tear they should get a consultation with a doctor who specializes in regenerative medicine to decide if surgery or a non-surgical option is the way to go. If surgery is the route to take, based on the patient’s desire to return to high-level competitive sport, then after surgery, Comprehensive Prolotherapy to help provided strengthened stability to the whole knee.
The ACL and degenerative meniscus disease
Patients who have ACL reconstructive surgery and those who forgo ACL reconstructive surgery are both at high risk for osteoarthritis of the knee. This was demonstrated in the research above and in new research from a team of Chinese researchers who published in the April 2018 edition of the American Journal of Sports Medicine found that the deterioration of meniscus was more extensive than that of articular cartilage and subchondral bone in animal studies. Partly in due to chronic inflammation and osteoarthritic changes to the extracellular matrix (the healing soup of cells). The fascinating subject of how Extracellular Matrix repairs cartilage is explained in our article. The researchers of this study noted that rupture of the ACL induced changes that not only could explain the contribution of the meniscus to the progress of osteoarthritis but also could provide a cue for initiation of preventive treatments in the early stages of osteoarthritis. (24)
The ACL and PCL (posterior cruciate ligament). The problems of identifying the source of ligament laxity and knee instability
The anterior cruciate ligament sits in front of the PCL and together the ACL and PCL keep the tibia (shin bone) from sliding too far forward and the tibia in the position below the femur (thigh bone). The PCL is the knee’s basic stabilizer and almost twice as strong as the ACL.
A 2018 study in the Journal of Surgery discusses the problems of identifying the true nature of knee instability causes and this research surrounds the PCL (25).
The researchers noted that “ACL tear in concomitant chronic ACL and posterior cruciate ligament (PCL) deficient knees may produce knee laxity, which is more difficult to assess on clinical examination, which in turn may affect the management algorithm of the patient.”
In our article Posterior Cruciate Ligament Injury and Treatments, we identify this problem and discuss the treatment of PCL damage. Briefly, we suggest: “Posterior cruciate ligament (PCL) injuries make up between 3 and 20 percent of all knee ligament injuries. However, PCL injuries are often left diagnosed. Why it is left undiagnosed and untreated is because the PCL is not well understood.”
Understanding and strengthening the PCL is an important factor in ACL injured knees.
All the ligaments of the knee work to stabilize an ACL injury and ACL deficient knee
The ACL’s job is to prevent the tibia and the femur from moving excessively on each other. When it is injured or not there, it puts stress on the other ligaments to prevent this excessive motion.
If you are debating ACL reconstruction because of long rehabilitation, unsureness that the surgery will be successful, already had one ACL reconstruction. Please consider a consultation. What we will discuss with you is:
- Surgery or non-surgical approaches
- The use of Prolotherapy, PRP, or stem cell treatments
- A realistic expectation of surgery and non-surgical treatment
Summary and contact us. Can we help you?
We hope you found this article informative and it helped answer many of the questions you may have surrounding your knee problems. If you would like to get more information specific to your challenges please email us: Get help and information from our Caring Medical staff
Brian Hutcheson, DC | Ross Hauser, MD | Danielle Steilen-Matias, PA-C
1 Kovalak E, Atay T, Çetin C, Atay İM, Serbest MO. Is ACL reconstruction a prerequisite for the patients having recreational sporting activities?. Acta Orthopaedica et Traumatologica Turcica. 2017 Dec 28. [Google Scholar]
2 Morris RC, Hulstyn MJ, Fleming BC, Owens BD, Fadale PD. Return to Play Following Anterior Cruciate Ligament Reconstruction. Clin Sports Med. 2016 Oct;35(4):655-68. [Google Scholar]
3 de Mille P, Osmak J. Performance: Bridging the gap after ACL surgery. Current reviews in musculoskeletal medicine. 2017 Sep 1;10(3):297-306. [Google Scholar]
4 McCarthy M, Dodwell E, Pan T, Green DW. Long Term Follow Up of Pediatric ACL Reconstruction in New York State: High Rates of Subsequent ACL Reconstruction. Orthopaedic journal of sports medicine. 2015 Jul 17;3(7_suppl2):2325967115S00129. [Google Scholar]
5 Osti L, Buda M, Osti R, Massari L, Maffulli N. Preoperative Planning for ACL Revision Surgery. Sports Med Arthrosc. 2017 Mar;25(1):19-29. [Google Scholar]
6 Westermann RW, Jones M, Wasserstein D, Spindler KP. Clinical and Radiographic Outcomes of Meniscus Surgery and Future Targets for Biologic Intervention: A review of data from the MOON Group. 20. Connect Tissue Res. 2017 Mar 10. doi: 10.1080/03008207.2017.1297808. [Google Scholar]
7 Di Benedetto P, Buttironi MM, Mancuso F, Beltrame A, Gisonni R, Causero A. Anterior cruciate ligament reconstruction: the role of lateral posterior tibial slope as a potential risk factor for failure. Acta Bio-medica: Atenei Parmensis. 2020 Dec 30;91(14-S):e2020024-. [Google Scholar]
8 Filbay SR, Grindem H. Evidence-based recommendations for the management of anterior cruciate ligament (ACL) rupture. Best Practice & Research Clinical Rheumatology. 2019 Feb 21. [Google Scholar]
9 van Yperen DT, Reijman M, van Es EM, Bierma-Zeinstra SM, Meuffels DE. Twenty-Year Follow-up Study Comparing Operative Versus Nonoperative Treatment of Anterior Cruciate Ligament Ruptures in High-Level Athletes. The American journal of sports medicine. 2018 Apr;46(5):1129-36. [Google Scholar]
10 Heijne A, Axelsson K, Werner S, Biguet G. Rehabilitation and recovery after anterior cruciate ligament reconstruction: patients’ experiences. Scand J Med Sci Sports. 2008 Jun;18(3):325-35. Epub 2007 Dec 7. [Google Scholar]
11 Alm L, Krause M, Frosch KH, Akoto R. Preoperative medial knee instability is an underestimated risk factor for failure of revision ACL reconstruction [published online ahead of print, 2020 Jul 3]. Knee Surg Sports Traumatol Arthrosc. 2020;10.1007/s00167-020-06133-y. doi:10.1007/s00167-020-06133-y [Google Scholar]
12 McCullough KA, Phelps KD, Spindler KP, Matava MJ, Dunn WR, Parker RD; MOON Group, Reinke EK. Return to High School- and College-Level Football After Anterior Cruciate Ligament Reconstruction: A Multicenter Orthopaedic Outcomes Network (MOON) Cohort Study. Am J Sports Med. 2012 Aug 24. [Google Scholar]
13 Shaerf DA, Pastides PS, Sarraf KM, Willis-Owen CA. Anterior cruciate ligament reconstruction best practice: A review of graft choice. World Journal of Orthopedics. 2014;5(1):23-29. doi:10.5312/wjo.v5.i1.23. [Google Scholar]
14 Makhni EC, Padaki AS, Petridis PD, Steinhaus ME, Ahmad CS, Cole BJ, Bach BR Jr. High Variability in Outcome Reporting Patterns in High-Impact ACL Literature. J Bone Joint Surg Am. 2015 Sep 16;97(18):1529-42. [Google Scholar]
15 Judge A, Arden NK, Cooper CC, Javaid MK, Carr AJ, Field RE, Dieppe PA. Predictors of outcomes of total knee replacement surgery. Rheumatology. 2012;51(10):1804-1813. These re-ruptures often lead to a second ACL reconstruction surgery. [Google Scholar]
16 Fayard JM, Sonnery-Cottet B, Vrgoc G, O’Loughlin P, de Mont Marin GD, Freychet B, Vieira TD, Thaunat M. Incidence and risk factors for a partial anterior cruciate ligament tear progressing to a complete tear after nonoperative treatment in patients younger than 30 years. Orthopaedic journal of sports medicine. 2019 Jul 16;7(7):2325967119856624. [Google Scholar]
17 Dallo I, Chahla J, Mitchell JJ, Pascual-Garrido C, Feagin JA, LaPrade RF. Biologic Approaches for the Treatment of Partial Tears of the Anterior Cruciate Ligament: A Current Concepts Review. Orthopaedic Journal of Sports Medicine. 2017 Jan 25;5(1):2325967116681724.[Google Scholar]
18 Reeves KD Hassanein K Long term effects of dextrose prolotherapy for anterior cruciate ligament laxity: A prospective and consecutive patient study. Alt Ther Hlth Med May-Jun 2003, 9(3): p58-62.[Google Scholar]
19 Hirzinger C, Tauber M, Korntner S, Quirchmayr M, Bauer HC, Traweger A, Tempfer H. ACL injuries and stem cell therapy. Archives of orthopaedic and trauma surgery. 2014 Nov 1;134(11):1573-8. [Google Scholar]
20 Sun Z, Li J. Research progress of tissue engineered ligaments Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2015 Sep;29(9):1160-6. Chinese. [Google Scholar]
21 Fu W, Li Q, Tang X, Chen G, Zhang C, Li J. Mesenchymal stem cells reside in anterior cruciate ligament remnants in situ. Int Orthop. 2015 Jul 31. [Google Scholar]
22 Jang KM, Lim HC, Bae JH. Curr Stem Cell Res Ther. 2015;10(6):535-47. Mesenchymal Stem Cells for Enhancing Biologic Healing after Anterior Cruciate Ligament Injuries. [Google Scholar]
23 Grote W, Delucia R, Waxman R, Zgierska A, Wilson J, Rabago D. Repair of a complete anterior cruciate tear using prolotherapy: a case report.Int Musculoskelet Med. 2009 Dec 1;31(4):159-165 [Google Scholar]
24 Xie J, Zhang D, Lin Y, Yuan Q, Zhou X. Anterior Cruciate Ligament Transection–Induced Cellular and Extracellular Events in Menisci: Implications for Osteoarthritis. The American journal of sports medicine. 2018 Mar 1:0363546518756087. [Google Scholar]
25 Sazali S, Rusdi A, Siti HT. Association of ACL Laxity Tests with Arthroscopic Findings in Chronic ACL and PCL Deficient Knees. The Surgery Journal. 2018 Jan;4(1):e43. [Google Scholar]
This article was updated March 6, 2021