Caring Medical - Where the world comes for ProlotherapyAfter ACL Reconstruction | Complications and post-surgery treatment options

Ross Hauser, MD  | Caring Medical Regenerative Medicine Clinics, Fort Myers, Florida
David N. Woznica, MD | Caring Medical Regenerative Medicine Clinics, Oak Park, Illinois
Danielle R. Steilen-Matias, MMS, PA-C | Caring Medical Regenerative Medicine Clinics, Oak Park, Illinois

After ACL Reconstruction, Complications and post-surgery knee instability treatments

When the other knee ligaments are too weak to support the new ACL, this causes ACL surgery failure.

In this article, we will discuss problems of knee instability following anterior cruciate ligament reconstruction surgery and review various non-surgical or revision treatment suggestions to stabilize the unstable post-ACL surgical knee.

ACL reconstructive surgery works for many patients. But how do we define the definition of “works.” Was the surgery successful but your knee still feels like it could give way? Maybe your knee bends backward a little further than you think it should. If so, was your surgery then really that successful?

  • Maybe you did have a successful surgery, however, as you are reading this article you are likely researching problems of an unstable knee that is preventing you from doing sports, work, or other daily routines.
  • It is also very likely that if you are reading this article, you had a less than successful surgery, your knee is very unstable and you are looking for answers that go beyond buying one knee brace after another.

Many patients that we see following an anterior cruciate ligament reconstruction surgery are confused. They thought for sure once they had the ACL surgery that they would be back to doing what they were doing with the same, if not better, knee than they had before the surgery. This despite the fact that their surgeon probably advised them of possible post-surgery problems, such as instability and the need for extensive rehabilitation.

Other patients recognized immediately that their surgery did not go that well. In immediate post-op rehabilitation, they suffered and may continue to suffer from post-surgical complications. They too are looking for answers beyond knee braces, extended physical therapy, painkillers and the constant reminders from their health care providers that knee replacement will likely be the ultimate solution down the road.

The appeal and enthusiasm for ACL reconstruction, is this misguided? Says the patient, “What other choice did I have?”

Many times we will see a patient following anterior cruciate ligament reconstruction. To these patients we ask a simple question:

  • “Why did you have the surgery?”

Many times the patient will give an equally simple answer:

  • What other choice did I have?”

There are options to the ACL surgery as we will discuss below: But you have already had the surgery, perhaps now you are being told to consider revision surgery. The second ACL surgery is also a very popular procedure, and sometimes it cannot be avoided.

The second ACL surgery or “revision surgery” is also a very popular procedure. It is also much less “successful.”

You are a young athlete, you are the parent of a young athlete, the clock is always ticking because a young athlete’s career is finite in years. There is a great sense of urgency to get the knee repaired ASAP.

  • Doctors writing in the American Journal of Sports Medicine (1) suggest that younger patients had a higher risk of revision ACL reconstruction than older patients and that subjective clinical outcome was worse after revision ACL reconstruction compared to primary ACL reconstruction.
    • Even though the second surgery was performed to fix the first surgery. You still had a high risk of being worse off after the second surgery.
    • They report that nearly 9% of patients under 20 need a second anterior cruciate ligament (ACL) Reconstruction Therapy.
  • Doctors reporting in the journal Clinical Orthopaedics and Related Research (2) also suggest that young, active, skeletally mature patients have higher failure rates after various surgical procedures, including primary ACL reconstruction.
    • While a single-stage transosseous revision (ACL tunnel repair surgery) restores knee stability, only 52% of these patients return to their prior level of activity or sport.

Tunnel placement complications

ACL tunnel complications

Image: Erickson B, et al. ORTHOPEDICS. 2016; 39: e456-e464.

If you had the ACL surgery you likely know all about tunnels. This is a significant complication of ACL reconstruction. As we are looking for solutions to your problem in this article we will only touch on this briefly. Tunnel problems are one of the problems where revision surgery is most likely warranted.

  • Tunnel widening (the hole gets bigger),
    • and tunnel misplacement (the tunnel was put in the wrong place),
    • and fracture (the tunnel hole was too wide and caused a fracture of the bone) are the more common complications.

During the ACL reconstruction surgery, a hole is drilled in the thigh bone and the shin bone, the donor tendon that is being used as the graft is then threaded through the holes, through the knee and fixed or screwed into place.

Why doctors want to avoid a revision surgery

  • Why doctors want to avoid a revision was pointed out in a study out of Norway in the journal Knee Surgery, Sports Traumatology, Arthroscopy: (3)
    • Researchers compared 56 patients undergoing a revision reconstruction to 52 patients undergoing a primary reconstruction surgery.
    • The results showed that the patients who had the second surgery had inferior results in almost every category of observation, including greater laxity, less muscle strength, and more severe radiological osteoarthritis.
  • In another study published in the American Journal of Sports Medicine, (4) doctors in France reported that while the second ACL reconstruction was excellent or good in 70% of the cases, HOWEVER, knee degeneration continued to occur because of stress and damage to the meniscus and articular cartilage. Meniscus tears were more frequent and more severe with recurrent laxity and knee instability.

Avoiding “Revision – Revision” – the Third ACL surgery – Back in the tunnels

Multiple studies have shown that the rate of return to the pre-injury level of sport is significantly lower following revision ACLR than following primary ACLR procedures.

Doctors writing in The Journal of Bone and Joint Surgery (5) suggest that it is important for orthopedic surgeons to attempt to restore proper anatomy and biomechanics during revision (the second ACL surgery) ACLR to minimize the rate of re-revision. (The third ACL surgery). Here are the surgeon’s checklist of guidelines.

  • They write that: Technical errors such as non-anatomic tunnel placement are some of the most common causes of graft failure after primary anterior cruciate ligament reconstruction.
  • When considering a revision ACLR in a patient with ACL graft failure, it is crucial to perform preoperative imaging, which should include an initial radiographic series, magnetic resonance imaging, and possibly computed tomography for further assessment of tunnel locations.
  • Revision ACLR may be performed in a 1 or 2-stage procedure depending on the size and location of the existing tunnels, bone stock, existing hardware, and infection status.
  • Use of autograft (patient) ligament tissue for revision ACLR has been shown to correlate with higher patient-reported outcomes and a significantly lower risk of subsequent graft rupture in comparison with allograft (donor) use.
  • Multiple studies have shown that the rate of return to the pre-injury level of sport is significantly lower following revision ACLR than following primary ACLR procedures.

It is important to consider that the findings above are considered excellent ACL reconstruction patient results. We ask, do these findings really merit an excellent? Here is more research to review:

  • ACL Reconstruction and the Meniscus: In the medical journal Arthroscopy, (6) doctors wrote: “Meniscectomy was performed in 65% of ACL tear procedures. This is concerning because studies have shown that, regardless of knee stability obtained after ACL reconstruction, meniscectomy accelerates degenerative joint changes.
  • ACL Reconstruction and Patellofemoral pain syndrome: Doctors writing in the journal Arthritis care & research, (7) note that Patellofemoral osteoarthritis is common following anterior cruciate ligament reconstruction and that post-surgical lack of knee rotation may be sufficient to initiate or accelerate patellofemoral cartilage degeneration.

The fact that your knee is moving towards inevitable knee replacement should tell you that every day your knee is getting weaker.

By this time you can see that we are building an argument that instability in the ACL Reconstructed knee leads to a more accelerated breakdown of the knee. This does not have to be solely an osteoarthritis knee replacement someday in the future, it is a problem you have today. But knee replacement is the general direction you are moving in. The fact that your knee is moving towards inevitable knee replacement should tell you that every day your knee is getting weaker.

Peripheral shift of joint forces with ligament injury

  • Researchers writing in the British Journal of Sports Medicine (8) found that if you had to have a revision or secondary ACL reconstruction surgery you were at advanced risk for osteoarthritis, ligament damage and weakness, and loss of knee function.
  • In fact, doctors writing in the Journal of Bone and Joint Surgery (9) wrote: “Despite the success of restoring joint stability and improving early functional outcomes after anterior cruciate ligament reconstruction, the long-term risk of developing symptomatic osteoarthritis requiring total knee replacement is higher than that in the uninjured population.”

Many people have issues with knee instability and function after anterior cruciate ligament reconstruction, it is not just you.

We have just presented a lot of research on the problems some patients have following ACL reconstruction surgery. But in reality, how often do ACL reconstruction complications and post-surgical concerns occur? If you are reading this article because you are considering an ACL surgery, you may think to yourself, how many people does this really affect?

For you who had the surgery, it has happened one time too many because you have a lot of knee problems. While you may be led to believe that this is a problem you suffer from a small minority of patients, it is NOT just you, it is a lot of patients. How big a problem is this in the medical community? Consider this:

In 2015, a paper appeared in the journal Clinical Orthopedic Sports Medicine, (10) it came from researchers at Johns Hopkins University. The researchers looked at all the medical studies published in the field of clinical sports medicine with the goal of finding the top 100 most cited medical articles. This was not just a study in statistics, the subject matter of the top 100 articles would tell doctors and other health professionals what some of the biggest challenges in medicine were and how researchers were moving toward possible solutions.

  • 15 of the 100 ( a very heavy influence) dealt with an injury to the ACL. 

In 2017, European researchers looked solely at the top ACL 50 articles. They published their results in the journal International Orthopaedics.(11)

The top three articles cited were articles that were related to defining a scoring system to help clinicians understand the severity of symptoms related to knee ligament problems. The number 1 article was the 1985 “Rating systems in the evaluation of knee ligament injuries”(12)  that lead to the “Tegner Lysholm Knee Scoring Scale.” A questionnaire to grade and assess the patient’s knee problems.

Now if you had an ACL reconstruction and you are experiencing continued problems, you may have been given the questionnaire or were asked questions that pertain to these following problems broken up into these sections.

  • Section 1 – Do you Limp?
  • Section 2 – Do you need help with walking? Do you use a cane, a crutch, can you support your own weight without assistance?
  • Section 3 – How much pain do you have? How much pain do you have after certain levels of exertion?
  • Section 4 – Instability – when does your knee “give out”? Always? Never? At certain amounts of exertion?
  • Section 5 – To what extent does your knee lock up?
  • Section 6 – To what extent does your knee swell? Is swelling constant?
  • Section 7 – Can you climb stairs?
  • Section 8 – Can you squat?

Based on the amount of time clinicians spend researching and citing articles on “Knee scoring systems, one could suggest that the biggest problem facing the clinician is how do you determine how bad off a patient’s knee is? Second what is causing these problems?

It is time to talk about the other ligaments of the knee –
When the other knee ligaments are too weak to support the new ACL, this causes ACL surgery failure.

The ACL ligament does not sit in isolation. Your problem may be a knee ligament problem and it is not just the ACL, it is the other ligaments.

Knee instabilities

The four major ligaments of the knee are:

Study: “Generalized Hypermobility, Knee Hyperextension, and Outcomes After Anterior Cruciate Ligament Reconstruction”

Let’s examine an October 2017 study in the medical journal Arthroscopy (13) led by the Minnesota Orthopedic Sports Medicine Institute and Department of Orthopedics, University of Michigan MedSport.

The title of the paper should say it all: Generalized Hypermobility, Knee Hyperextension, and Outcomes After Anterior Cruciate Ligament Reconstruction.

Here are the summary findings:

  • Doctors looked at 183  (knees) patients two years removed from ACL reconstruction
  • Patients underwent ACLR with either bone-patellar-tendon autograft, quadrupled hamstring autograft or allograft tissue.

Knee Hypermobility – instability

  • Of the 183 patients:
    • Forty-one of 183 consecutive patients were categorized as hypermobile.
    • The remaining 142 were categorized as non-hypermobile.
  • ACL reconstruction failure was higher in the Hypermobile group (24.4% failure rate) compared with the Non-hypermobile group (7.7% failure rate)
  • The overall ACL injury rate (ACL graft injury, excessive graft laxity, plus contralateral (the other knee) ACL tear) was higher in the Hypermobile group (34.1%) compared with the Non-hypermobile group (12.0%)

In this above study, the focus is put on the ACL graft being too loose or lax. The new ACL is not holding the knee together as it should and this is causing whole knee instability.

  • BUT, what if the ACL graft was put into a knee that was already suffering from ligament laxity from the other ligaments?

“Preoperative laxity of the knee” and “Excessive graft laxity” as a cause of ACL surgery failure

Let’s go back to 2001 and a well-documented summary of ACL complications that can be found in the abstract of a classic lecture presentation from Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh. This lecture was delivered in 2001. (14)

From 2001: “Many factors influence the overall success or failure of anterior cruciate ligament reconstruction, including the integrity of the secondary restraints (that is the supporting structures of the knee), the collateral ligaments, the mid-third capsular ligaments, the meniscus, and the iliotibial band), the preoperative laxity of the knee, the status of the articular and meniscal cartilage. . . “

As we noted in the research above untreated associated ligaments insufficiencies, in other words, the other knee ligaments were too weak to support the new ACL, this caused failure.

The prevalence of knee hyperextension (knee instability) in ACL revision surgery patients

We are now going to move forward to an October 2018 in the American Journal of Sports Medicine.(15)

This is a huge study listing dozens of authors. The study’s abstract lists that the investigation was performed at The Carrell Clinic, Dallas, the Department of Orthopaedics, Washington University School of Medicine, St Louis, the Department of Orthopaedics and Rehabilitation, Vanderbilt University Medical Center, and Reedsburg Area Medical Center, Reedsburg, Wisconsin.

The researchers in this study were presenting a hypothesis about the impact of knee hyperextension in revision ACL reconstruction surgery. Knee hyperextension being defined as a 5 degree ability to bend the knee backward.

So the researchers went about examining ACL reconstruction patients for two years.

  • The average age of the patient was 26 years old
  • 42% of patients were female
  • There were 50% autografts, 48% allografts, and 2% that had a combination of autograft plus allograft.
  • Graft rupture was more prevalent in:
    • Younger patients
    • Those patients who used allograft
    • and patients who had hyperextension of greater than 5 degrees.

Conclusion of the study? 

  • This study revealed that preoperative physiologic passive knee hyperextension of greater than 5 degrees is present in one-third of patients who undergo revision ACLR.
  • Knee hyperextension of greater than 5 degrees is an independent significant predictor of graft failure after revision ACLR with a more than 2-fold risk of subsequent graft rupture in revision ACL surgery.

Knee cap pain after knee replacement

Many patients continue to suffer pain in the front of the knee. Their doctors in many cases, isolate this to the problems of the knee cap (patella). The patella can be a big problem in knee replacement complications.

In December 2018, a team of Italian surgeons made these observations in the medical journal Joints (16)

People still have pain after knee replacement

Total knee replacement is the best treatment for advanced knee osteoarthritis and it has proven to be durable and effective. Anterior knee pain is still one of the most frequent complications after total knee replacement, but sometimes no recognized macroscopic (obvious defects or structural impairments) causes can be found.

Pain coming from the front of the knee should be considered a problem of the patella

The correct treatment of patella is considered the key to proper management of anterior knee pain. The inclusion of patellar resurfacing during total knee replacement has been described as a potential method for the reduction of anterior knee pain.

Patella resurfacing during total knee surgery not only DID NOT fix the problem, it made it worse

After surgeons started to resurface the patella, new complications emerged, such as component failure, instability, fracture, tendon rupture, and soft tissue impingement.

Patelloplasty (the shaving and reshaping of the knee cap) has been proposed as a good alternative to resurfacing but whether or not to resurface the patella is still a controversial topic in the literature.

The regenerative approach to Knee ligament weakness and degenerative injury

Throughout this article, we demonstrated research from the surgical community that discusses the problems of knee instability following an ACL reconstruction surgery. These problems can be severe enough that a second or even third surgery may be suggested. We have also demonstrated that these revision surgeries are, for the most part, less successful than the patient expects.

Knee regeneration vs. degeneration

The problem of knee instability is a problem of damaged, untreated degenerative structures. This includes the three other main stabilizing ligaments in the knee the MCL, PLC, and LCL.

In the case of an overstretched or partially torn ligament, a treatment approach to strengthen and heal the injured ligament should be utilized. The treatment that stimulates ligament healing and regeneration is Prolotherapy.

This article continues with non-surgical options > Is ACL reconstruction the only option?

If you have questions about ACL reconstruction options, you can get help and information from our Caring Medical Staff



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