Ross Hauser, MD; Danielle Matias, PA-C; Demi Foster, APRN

Spontaneous healing of a ruptured anterior cruciate ligament (ACL) is possible – This is not the case for elite athletes.

An October 2023 paper published in the International journal of sports physical therapy (9) suggests that a small portion of patient my spontaneously heal their ACL on their own without surgery. The authors write: satisfactory functional results after spontaneous healing of a ruptured anterior cruciate ligament (ACL) is possible, but “there is still a lot to understand in how an injured ACL may heal. The researchers write: “There is evidence that conservative treatment can be successful in the general population, with some people healing their ACL. This is not the case for elite athletes. The emerging evidence regarding the ability for the ACL to heal is intriguing and may change clinical practice in the future, but we urge clinicians to take these results with extreme caution as this may only be suitable for a very small percentage of the population.”

9 Forelli F, Riera J, Mazeas J, Coulondre C, Putnis S, Neri T, Rambaud A. Ligament Healing After Anterior Cruciate Ligament Rupture: An Important New Patient Pathway?. International Journal of Sports Physical Therapy. 2023;18(5):1032.

Patients can expect a 70% return-to-sport within seven years after ACL Reconstruction

A January 2022 study (27) in The American Journal of Sports Medicine discussed long-term patient-reported rates of return to sport and revision risk after ACL reconstruction.

There were 1045  reported patient outcomes in this study:

• Autografts were used in 76% of the patients (patellar tendon, 62%; hamstring grafts, 38%).
• Allografts were used in 24% of patients.
• Patients were surveyed on average 7.2 years after their ACL reconstruction surgery.
• Improvements were recorded in most patients’ knees.
• The strongest predictor for lesser improvement was cartilage damage identified during the ACL reconstruction surgery. Meniscal lesions did not predict failure or complication of surgery
• A total of 69% of patients had returned to the sport after 8.1 years (range, 6.7-9.8 years).
• The main reason for not returning to sport was fear of reinjury.
• The revision rate was 7.2% after 9 years (range, 8-11 years), 13% of patients needed subsequent ipsilateral (same side) non-ACL surgery, and 6% underwent contralateral (other side) ACL reconstruction surgery.
• The absence of a meniscal tear, younger age, and male sex were predictors for (greater chance) for revision.
• Graft choice did not predict patient-reported outcome results or revision risk.
• Conclusion: There is a 26% chance of subsequent knee surgery within 9 years, including a revision rate of 7%, subsequent non-ACL surgery to the operated knee in 13%, and a 6% chance of contralateral ACL reconstruction surgery.

The more revision surgeries, the fewer sports

The Department of Orthopedic Surgery at the Mayo Clinic published findings in the American Journal of Sports Medicine. (9) Here they write: “Continuously increasing numbers of primary anterior cruciate ligament reconstructions invites a parallel increase in graft failures and need for revision ACL reconstruction surgery. High failure rates have previously stigmatized the revision surgery. . . Good outcomes of revision ACL reconstruction surgery are achievable. The use of different graft types did not affect the outcome of the procedure. Most of the patients opted for less aggressive sports participation after the revision procedure.”

Poor return-to-sport rates and a high risk of secondary re-injury – can early physical therapy help post-surgery?

A January 2024 study (36) wrote: “Early-stage rehabilitation is the vital foundation on which successful rehabilitation post-ACLR can occur. Without high-quality early-stage (and pre-operative) rehabilitation, patients often do not overcome major aspects of dysfunction, which limits knee function and the ability to transition through subsequent stages of rehabilitation optimally.” The researches suggested doctors look at the six main patient challanges following ACLR: a) pain and swelling; b) knee joint range of motion; c) arthrogenic muscle inhibition and muscle strength; d) movement quality/neuromuscular control during activities of daily living; e) psycho-social-cultural and environmental factors and f) physical fitness preservation or simp[ly the ability to stay in shape.

36 Buckthorpe M, Gokeler A, Herrington L, Hughes M, Grassi A, Wadey R, Patterson S, Compagnin A, La Rosa G, Della Villa F. Optimising the Early-Stage Rehabilitation Process Post-ACL Reconstruction. Sports Medicine. 2023 Oct 3:1-24. [Google Scholar]

 

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

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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.

In 2017, doctors writing in The Journal of Bone and Joint Surgery (11) 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 is 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, (12) 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, (13) 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 young athlete’s knee is not the same after ACL reconstruction

A January 2022 study in the Orthopaedic Journal of Sports Medicine (26) suggests that athletes display persistent muscle deficits (weakness) and altered limb-loading mechanics at the time of return to sport after anterior cruciate ligament reconstruction. How much deficit and altered mechanics? To find out the researchers compared adolescent athletes’ function and playing ability when they returned to sports following ACL reconstruction to adolescent athletes who never had ACL reconstruction.

• There were 124 participants in this study; 62 patients who underwent ACL reconstruction (average age about 15.5 years old) and 62 healthy controls (average age about 15.3 years old).
• Tests were done to capture joint motions during jump landing and single-limb squat tasks.
• For jump landing, patients who underwent ACL reconstruction utilized significantly greater hip and significantly less knee power on the surgical limb compared with controls.
• During single-limb squat, patients who underwent ACL reconstruction utilized significantly greater hip and significantly less knee power on the surgical limb compared with controls.
• The ACL reconstruction group demonstrated lower pain and function scores and significantly lower quadriceps strength on the surgical limb than controls. There were no differences in surgical limb hamstring strength between the ACL reconstruction group and healthy controls.

Conclusion: “Compared with matched healthy controls, the participants who underwent ACL reconstruction in this study demonstrated an inferior objective profile (less strength and function) at a return to sport, consisting of deficits in surgical limb loading, self-reported outcomes, and strength.”

The younger hamstring graft is too stiff – Younger patients have worse surgical outcomes

A January 2022 study in the International Orthopaedics (31) by researchers at the University of Auckland. In this study, they examined if a younger patient’s hamstring tendon was “too stiff.” Here are the learning points of their study:

•  “The hamstring tendon is the most commonly used autograft material in reconstructive surgeries of anterior cruciate ligament (ACL) tears. Younger patients have worse surgical outcomes, with a higher risk of re-rupture. (The researchers) hypothesized that age-related changes in hamstring tendon properties affect the tendon’s propensity to rupture when used as an autograft in ACL reconstructions.”

The researchers then compared hamstring tendon samples obtained from people aged 20 years or younger to samples obtained from older people.

• The researchers found that tendon samples from the older group (stretched more easily) than the younger group, whereas the stress to failure was similar in the two groups.
• The hamstring tendon from younger people has higher stiffness than tendon from older people, and the profile of gene expression (the ability to make proteins and signal or communicate with other cells in the knee)  in (the) tendon varies with age. These differences may negatively affect the performance of the hamstring tendon in ACL reconstructions in younger people.

Knee function deficits following ACL reconstruction measured by loss of vertical jump distance

An international team of researchers published their May 2022 study (32) in the British journal of sports medicine in which they suggested that male athletes perform a single leg vertical jump test to help identify performance and knee function deficits (weakness) at return to sport after ACL reconstruction. From the study: “Vertical jump performance (the power, acceleration and height the athlete can achieve in the jump) is a more representative metric (test) for knee function than horizontal hop performance (jump height and distance) in healthy individuals.”

The purpose of this study was more to determine if the vertical test accurately portrayed knee strength in the ACL reconstruction athlete, as the researchers noted: “It is not known what the biomechanical status of athletes after anterior cruciate ligament (ACL) reconstruction (ACLR) is at the time they are cleared to return to sport or whether vertical performance metrics better evaluate knee function.”

In determining the effectiveness of the vertical test to portray knee deficits in the ACL reconstruction patient, the researchers found: Jump performance, assessed by jump height and Reactive Strength Index (a test that may be best described as “explosiveness” with a main factor of this test vertical jumping height), was significantly lower in the ACL reconstructed knee than the non reconstructed knee and compared against controls (people who did not have surgery), with large effect sizes.

The conclusion of this study was: “During vertical jumps, male athletes after ACL reconstruction at return to sport still exhibit knee biomechanical deficits, despite symmetry in horizontal functional performance and strength tests. Vertical performance metrics like jump height and Reactive Strength Index can better identify interlimb asymmetries than the more commonly used hop distance and should be included in the testing battery for the return to sport.” In other words, jumping is a problem and it is better assessed with tests that can evaluate jumping height and explosiveness.

Ten years later, my knee is still not the same

In some patients, their knee is not the same. In some patients, ten years later their knee is not the same. Some people do very well with ACL reconstruction surgery, some do very well with second or revision ACL surgery. Some do well with the third ACL reconstruction/revision surgery. These are typically not the people we see in our office. We see the people who may have had a successful surgery, but their knee is not the same. They tell us stories like this one:

When I had the ACL reconstruction I had a difficult rehab. Maybe because I was pushing myself too hard. My knee just did not feel right. Almost a year after the surgery, the graft gave way and it pretty much wiped out my meniscus. In the revision surgery a tendon graft was used and most of my meniscus, which I was told was beyond repair, was removed. The surgery was a great success but my knee was never the same. I never really recovered. Here I am 10 years later now being managed along until I can get a knee replacement.

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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.

• Researchers writing in the British Journal of Sports Medicine (14) 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 (15) 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.”

 

https://pmc.ncbi.nlm.nih.gov/articles/PMC9756873/

This study identifies risk factors for nRTA limited to a previously active population. Patients who report worse scores at two years have a clinically meaningful decline across all PROs, yet active patients at baseline still participate in activities two years after surgery. Results suggest activity participation is not necessarily associated with a healthy and highly functional knee. Changes in two-year PROs do not vary between recreational and high-level participants.

What if I buy a really good brace? Study: Knee bracing does not appear to improve the clinical outcomes on the function and stability of ACL-reconstructed knees

An October 2019 study in the journal Orthopaedics and Traumatology, Surgery and Research (19) suggests that “knee braces could not provide superior clinical outcomes on knee functional scores and stability evaluations.”

Here is what they said:

• “Knee brace has been commonly used as a device to protect the graft after reconstruction of anterior cruciate ligament (ACL). Studies have focused on the effects of braces after ACL reconstruction, and controversial results were reported.”

In this study, the researchers combined data from seven studies with 440 participants. After examining the patient outcomes following ACL reconstruction outcomes, the research team found:

• “Knee bracing does not appear to improve the clinical outcomes on the function and stability for ACL-reconstructed knees. Thus, bracing for patients treated with ACL reconstruction should not be recommended routinely.“

Does hyaluronic acid injections help with swelling and joint stiffness after ACL reconstruction?

A March 2022 paper in the Journal of clinical orthopaedics and trauma (33) sought to examine the effectiveness of hyaluronic acid injections in helping post ACL reconstruction patients with their problems of pain, swelling and joint stiffness. The study notes: “The patients often receive prolonged analgesic medications to control the inflammatory response and resume the pre-injury activities.”

This review study examined data from four previously published studies. In total 303 patients were assessed, 182 patients in the intraarticular hyaluronic acid injection group and 121 patients in the control group. The study analysis revealed: “Although the individual study demonstrated a short-term positive response regarding pain control and swelling reduction, the pooled analysis did not find any clinical benefit of intraarticular hyaluronic acid injection following ACLR surgery.”

PRP and bone marrow aspirate used during ACL reconstruction

A January 2024 study published in the Journal of orthopaedic surgery and research (35) examinedpatient outcomes following the application of bone marrow aspirate concentration and PRP during ACL reconstruction. (The study indicated the limited enhancing effect in clinical function, (ACL) graft maturation and tendon–bone interfacial healing, with only significant knee laxity improvement in the bone marrow aspirate concentration + PRP group at 24 weeks.

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.

The four major ligaments of the knee are:

• the anterior cruciate ligament (ACL),
• the posterior cruciate ligament (PCL),
• the medial collateral ligament (MCL),
• the lateral collateral ligament (LCL).
• The wildcard in this is a 5th knee ligament, the “rogue influence” and “controversial” anterolateral ligament.

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

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Let’s examine an October 2017 study in the medical journal Arthroscopy (20) 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 the Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh. This lecture was delivered in 2001. (21)

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, which caused the failure.

The prevalence of knee hyperextension (knee instability) in ACL revision surgery patients
Research 2018-2021

We are now going to move forward to October 2018 in the American Journal of Sports Medicine. (22)

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 presented a hypothesis about the impact of knee hyperextension in revision ACL reconstruction surgery. Knee hyperextension is 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 allografts.
• 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.

“Revision anterior cruciate ligament reconstruction restores knee laxity but shows inferior functional knee outcome”

Here is a 2019 study from the Stockholm Sports Trauma Research Center, Karolinska Institutet, Stockholm, Sweden published in the journal Knee surgery, sports traumatology, arthroscopy (23). What the researchers found was that a revision ACL reconstruction laxity problem can be surgically fixed, but it could not fix problems with knee function in many patients.

The researchers wrote “the final postoperative functional outcome is inferior”

“The findings of this study showed that anterior knee laxity is restored with revision bone-patellar tendon-bone autograft ACLR after failed primary hamstring tendons autograft ACLR, in the same cohort of patients. However, revision ACLR showed a significantly inferior functional knee outcome compared with primary ACLR. It is important for clinicians to inform and set realistic expectations for patients undergoing revision ACLR. Patients must be aware of the fact that having revision ACLR their knee function will not improve as much as with primary ACLR and the final postoperative functional outcome is inferior.”

 “Preoperative medial knee instability is an underestimated risk factor for revision ACLR failure”

University medical researchers in Germany published a July 2020 study in the journal Knee Surgery, Sports Traumatology, Arthroscopy (24) that warned their colleagues that a loose knee after ACL reconstruction is a leading cause for ACL reconstruction failure.

The researchers wrote: “The most important finding of this study was that preoperative medial knee instability is a risk factor for revision ACLR”

“The most important finding of this study was that preoperative medial knee instability is a risk factor for revision ACL reconstruction and should be adequately addressed at the time of revision ACL reconstruction. This study demonstrates the largest revision ACL reconstruction patient group with pre-and postoperative clinical examination data and a follow-up of 2 years published to date and it indicates that preoperative knee instability is an important factor for the treatment strategy of revision ACL reconstruction. Medial knee instability, high-grade anterior knee instability, and increased posterior tibial slope are risk factors for failure of revision ACL reconstruction and should be addressed at the time of revision surgery.”

“In spite of supposedly successful surgery, slight residual knee laxity may be found at follow-up evaluations after anterior cruciate ligament reconstruction (ACLR), and its clinical effect is undetermined”

Finally, a March 2021 study in The American Journal of Sports Medicine (25) wrote: “In spite of supposedly successful surgery, slight residual knee laxity may be found at follow-up evaluations after anterior cruciate ligament reconstruction, and its clinical effect is undetermined. . . In spite of supposedly successful surgery, slight residual knee laxity may be found at follow-up evaluations after anterior cruciate ligament reconstruction, and its clinical effect is undetermined

Conclusion: “A slightly loose graft at 6 months after anterior cruciate ligament reconstruction increased the risk of later ACL revision surgery and/or graft failure, reduced the length of the athlete’s sports career, caused permanent increased anterior laxity, and led to an inferior Lysholm (pain, disability, function) score.”

The road to preventing ACL revision surgery – ligament strengthening

In this video Ross Hauser, MD explains a simple injection technique – Prolotherapy for strengthening the ACL

Video transcript summary:

• For Grade 1 and Grade 2 tear of ACL, Prolotherapy injections can be an effective non-surgical option
• If somebody has a complete anterior cruciate ligament tear they should get surgery to repair it but then after surgery Prolotherapy should be considered because Prolotherapy will stimulate the healing and strengthening of the attachments of the transplanted ACL. There are two attachments of the anterior cruciate ligament – at the tibial tubercle and at the lateral femoral condyle. Prolotherapy strengthens these attachment points.
• Prolotherapy is very effective at decreasing the pain, knee instability and the inability to exercise that occurs with ACL weakness or injury.
• Athletes and non-athletes – people with physically demanding work can continue to train or work during treatment – there is typically no reason for immobilization.

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.

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.

In this video, Danielle R. Steilen-Matias, MMS, PA-C, of Caring Medical demonstrates how we treat a patient with a primary complaint of knee osteoarthritis.

• The person in this video is being treated for knee osteoarthritis as the primary complaint. The treatment takes a few minutes. The person in this video is not sedated and tolerates the treatment very well. For some patients, we do provide IV or oral medications to lessen treatment anxiety and pain.
• The first injection is given to the knee joint. The Prolotherapy solution is given here to stimulate repair of the knee cartilage, meniscal tissue, and the ACL as well.
• The injections continue over the medial joint line making sure that all the tendons and ligaments such as the medial collateral ligament are treated.
• This patient-reported the greatest amount of pain along the medial joint line. This is why a greater concentration of injections is given here.
• The injections continue on the lateral side of the knee, treating the lateral joint line all the tendon and ligament attachments there such as the LCL or lateral collateral ligament.

Summary and Questions about our treatments?

Surgical outcomes for ACL tears have their own fair share of disappointing results, including as high failure rates as demonstrated in the research above. Second ACL tears or the need for later revision surgery will all but end a young athlete’s career. Using tissue from cadavers (allograft) or from a patient’s own tissue (autograft) is used for ACL reconstruction, as well as for many other areas of the body because it sounds promising to a patient in pain who is looking for repair, and is necessary in the instance of grade III (complete) tears. Despite the reconstructive surgery, the instability of the knee remains and that knee is in jeopardy for future injury.

ACL reconstruction can provide remarkable short-term pain relief. Temporarily they provide more stability to the joint. Unfortunately, the stability doesn’t last because the “new” ACL can not simulate exactly the same biology of the original ACL. If someone has a complete, grade 3 ligament tear, surgery is indicated. The cadaver or tendon graft that is replacing the torn ligament, however, will not function long-term like the original ACL. Once it starts becoming lax or weak, Knee instability occurs.

ACL grafts do not have the same pliability as nascent tissue. In other words, ligaments are pliable, they can stretch. Surgerized ACL no longer has the pliability and for the active person will cause long-term problems.

If you have questions about your knee pain and how we may be able to help you, please contact us and get help and information from our Caring Medical staff.

 

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References: 

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32 Kotsifaki A, Van Rossom S, Whiteley R, Korakakis V, Bahr R, Sideris V, Jonkers I. Single leg vertical jump performance identifies knee function deficits at return to sport after ACL reconstruction in male athletes. British Journal of Sports Medicine. 2022 Feb 7. [Google Scholar]
33 Tripathy SK, Varghese P, Behera H, Balagod R, Rao PB, Sahoo AK, Panda A. Intraarticular viscosupplementation following arthroscopic anterior cruciate ligament reconstruction: A systematic review. Journal of Clinical Orthopaedics & Trauma. 2022 May 1;28. [Google Scholar]
34 Gursoy S, Clapp IM, Perry AK, Kerzner B, Singh H, Vadhera AS, Bach Jr BR, Bush-Joseph CA, Forsythe B, Yanke AB, Verma NN. Patients Follow Three Different Rate of Recovery Patterns Following Anterior Cruciate Ligament Reconstruction Based on IKDC Score. Arthroscopy: The Journal of Arthroscopic & Related Surgery. 2022 Mar 22. [Google Scholar]
35 Lin YC, Chen YJ, Fan TY, Chou PH, Lu CC. Effect of bone marrow aspiration concentrate and platelet-rich plasma combination in anterior cruciate ligament reconstruction: a randomized, prospective, double-blinded study. Journal of Orthopaedic Surgery and Research. 2024 Jan 3;19(1):4. [Google Scholar]

 

 

 

Goes to another article not updated

In a January 2024 study (x), doctors administered PRP therapy within six weeks after ACL injury in patients who expressed the desire for an early return to sports through conservative care. After the treatment, patients wore a simple brace that limited deep flexion but placed no restrictions on weight bearing. Four months was the standard goal established for returning to pre-injury condition. The average patient age was 32.7 years and the average treatment was 2.8 PRP sessions.

MRI evaluations confirmed that ligament continuity was regained in all cases. All the patients returned to their pre-injury level in an average of 139.5 days, but there was one instance of re-rupture following the return to sports.

x Hada S, Hada M, Yoshida K, Kaneko H, Saita Y, Kubota M, Ishijima M. Conservative Treatment Using Platelet-Rich Plasma for Acute Anterior Cruciate Ligament Injuries in Highly Active Patients: A Retrospective Survey. Cureus. 2024 Jan;16(1).

ACL and Meniscus not updated

A January 2024 study (x) suggested that doctors could better identify patients with ACL and meniscus damage with a high-grade Lachman’s exam (physical examination), specifically in males who had higher risk of having an ACL tear with a concomitant medial meniscus ramp tear. The researchers suggest that an ACL tear with concomitant medial meniscus ramp tear may be better diagnosed based upon the clinical evaluation rather than other secondary radiological findings.

x  Familiari F, Tollefson LV, Izzo A, Mercurio M, LaPrade RF, Di Vico G. A High-Grade Lachman’s Exam Predicts a Ramp Tear of the Medial Meniscus in Patients with Anterior Cruciate Ligament Tear: A Prospective Clinical and Radiological Evaluation. Journal of Clinical Medicine. 2024 Jan 24;13(3):683.

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PRP and Stem Cells ACL repair and reconstruction not updated

A September 2024 study (x) writes: “Emerging trends and future directions in ACL reconstruction are centered on advancements in biological augmentation, innovations in surgical techniques, and the need for comprehensive long-term outcome studies. Biological augmentation methods, such as platelet-rich plasma and stem cells, are increasingly recognized as promising options for enhancing ACL repair and reconstruction. These biological agents aim to create a more conducive healing environment for the graft, which could lead to improved clinical outcomes.”

x  Gharpinde MR, Jaiswal AM, Dhanwani Y. A Comprehensive Review of Graft Choices and Surgical Techniques in Primary Anterior Cruciate Ligament Reconstruction: An Outcome Analysis. Cureus. 2024 Sep;16(9).

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Jumping after ACLR

A March 2023 study (x) of 40 patients who underwent ACLR 6 months before (18 females/22 males about 19 years old) demonstrated knee-avoidant jumping mechanics and had significant reductions in knee joint power (quadricep strength) on the surgically repaired limb side.
x Graham MC, Reeves KA, Johnson DL, Noehren B. Relationship between quadriceps strength and knee joint power during jumping after ACLR. Orthopaedic Journal of Sports Medicine. 2023 Mar 31;11(3):23259671231150938.

The kenetics of the knee

A study looking at the rate and timing of same side ACL revision (x) or opposite knee ACL reconstruction found that in outcomes of 1689 patients who required ACL revision or opposite side reconstruction, found 1018 patients with same side revision surgery (60.3%) and other side reconstruction for 671 (39.7%) patients. Patients returning for same side reconstruction did so sooner than patients needing other knee reconstruction. The overall rate of requiring a subsequent ACL revision was found to be 4.2%.

x Halperin SJ, Dhodapkar MM, McLaughlin WM, Hewett TE, Grauer JN, Medvecky MJ. Rate and Timing of Revision and Contralateral Anterior Cruciate Ligament Reconstruction Relative to Index Surgery. Orthopaedic Journal of Sports Medicine. 2024 Oct;12(10):23259671241274671.

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50 Kleinsmith RM, Doxey SA, Huyke-Hernández FA, Kweon CY, Cunningham BP. Autograft and Allograft ACLR in Patients Greater Than 40 Years Old Have Similar Short-Term Patient-Reported Outcomes with Higher Rates of ACL Graft Failure in Allograft Patients. Arthroscopy: The Journal of Arthroscopic & Related Surgery. 2024 Sep 26.
49 Kurokawa T, Csete K, Jávor P, Sándor L, Baráth B, Holovic H, Török L, Hartmann P. Anterior cruciate ligament reconstruction in the elderly: 5-Year follow-up study. Injury. 2024 Sep 1;55:111529.
44 LaPrade CM, Homan MD, Moran J, Kennedy NI, LaPrade RF. Concurrent repair of medial meniscal ramp lesions and lateral meniscus root tears in patients undergoing anterior cruciate ligament reconstruction: the “New Terrible Triad”. Arthroscopy Techniques. 2023 Sep 1;12(9):e1565-78.

14 Migliorini F, Vecchio G, Eschweiler J, Schneider SM, Hildebrand F, Maffulli N. Reduced knee laxity and failure rate following anterior cruciate ligament reconstruction compared with repair for acute tears: a meta-analysis. Journal of Orthopaedics and Traumatology. 2023 Feb 20;24(1):8.
17 Min JH, Yoon HK, Oh HC, Youk T, Ha JW, Park SH. Graft choice to decrease the revision rate of anterior cruciate ligament reconstruction: a nationwide retrospective cohort study. Scientific Reports. 2024 Aug 28;14(1):20004.
58 Munde K, Banerjee S, Gahlot N, Elhence A, Mandal S, Yadav T. Effect of platelet-rich plasma on healing of autologous graft after anterior cruciate ligament reconstruction: a randomized control trial. Regenerative Medicine. 2023 Aug;18(8):601-10.
3 Paris AN, Colin NG, Gatt T, Galdes N, Wehbi H, Marston D, Galdes D, Carabott N, Esposito I. Return to sport, re-injury and performance after the anterior cruciate ligament reconstruction: evaluating the role of International Knee Documentation Committee (IKDC) and Knee Injury and Osteoarthritis Outcome Score (KOOS) scoring systems. Cureus. 2024 Apr;16(4).
10 Previ L, Monaco E, Carrozzo A, Fedeli G, Annibaldi A, Cantagalli MR, Rossi G, Ferretti A. Spontaneous healing of a ruptured anterior cruciate ligament: a case series and literature review. Journal of Experimental Orthopaedics. 2023;10(1):11.
16 Reinerink JM, Vendrig T, Keizer MN, Hoogeslag RA, Brouwer RW. One type of graft for reconstruction of the ACL does not suit all patients based on their characteristics and sports: a scoping review. Musculoskeletal surgery. 2024 Sep 9:1-1.
52 Sell TC, Zerega R, King V, Reiter CR, Wrona H, Bullock GS, Mills N, Räisänen A, Ledbetter L, Collins GS, Kvist J. Anterior Cruciate Ligament Return to Sport after Injury Scale (ACL-RSI) Scores over Time After Anterior Cruciate Ligament Reconstruction: A Systematic Review with Meta-analysis. Sports Medicine-Open. 2024 Apr 30;10(1):49.
53 Sengoku T, Takata Y, Yoshimizu R, Kimura M, Kanayama T, Kitaoka K, Nakase J. Preoperative Psychological Competitive Ability Is Associated With Emotional States Six Months After Anterior Cruciate Ligament Reconstruction With Hamstring Autograft: A Prospective Study. Cureus. 2024 Sep 10;16(9).
26 Tosarelli F, Buckthorpe M, Di Paolo S, Grassi A, Rodas G, Zaffagnini S, Nanni G, Della Villa F. Video analysis of anterior cruciate ligament injuries in male professional basketball players: injury mechanisms, situational patterns, and biomechanics. Orthopaedic journal of sports medicine. 2024 Mar;12(3):23259671241234880.
2 Wenning M, Sofack GN, Zöller D, Mauch M, Heitner AH, Paul J, Zahn P, Ritzmann R. Predicting the Recovery of Isokinetic Knee Strength 6 Months After Anterior Cruciate Ligament Reconstruction. Orthopaedic Journal of Sports Medicine. 2024 Sep;12(9):23259671241264845.

 

 

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A study looking at the rate and timing of same side ACL revision (22) or opposite knee ACL reconstruction found that in outcomes of 1689 patients who required ACL revision or opposite side reconstruction, found 1018 patients with same side revision surgery (60.3%) and other side reconstruction for 671 (39.7%) patients. Patients returning for same side reconstruction did so sooner than patients needing other knee reconstruction. The overall rate of requiring a subsequent ACL revision was found to be 4.2%.

A July 2024 study (24) assessed the association between knee laxity 6 months after primary ACLR was associated with the 1-, 2-, and 5-year subjective knee outcomes or revision ACLR at a 5-year follow-up.

• The study group was patients who underwent primary ACLR with a hamstring tendon autograft with no concomitant ligamentous injuries
• Anterior knee laxity was assessed 6 months postoperatively.
• The Knee injury and Osteoarthritis Outcome Score (KOOS) was collected preoperatively and 1, 2, and 5 years postoperatively.
• A total of 4697 patients (54.3% male) were included.
• A high grade of postoperative knee laxity 6 months after primary ACLR was associated with an increased hazard of revision ACLR within 5 years.

Knee laxity in athletes following ACL surgery: The problem of a loose anterior cruciate ligament graft causing the need for a revision ACL surgery reconstruction

A 2019 sports medicine study (25) examined a second or revision ACL surgery’s ability to fix this looseness.

The study authors examined:

• Patients who underwent primary and revision ACL reconstruction.
• Inclusion criteria were: same patients who underwent primary hamstring tendons and revision bone-patellar tendon-bone autograft ACLR, no associated ligament injuries and no contralateral ACL injuries/reconstructions.
• The cause of revision ACLR was graft rupture for all patients.
• A total of 118 patients with primary and revision ACLR arthrometric laxity measurements were available.

The mean preoperative and postoperative anterior side-to-side difference values were not significantly different between primary and revision ACLR. However, primary ACLR showed a significantly higher frequency of postoperative anterior side-to-side difference difference  compared with revision ACLR.

Conclusions: “The findings of this study showed that anterior knee laxity is restored with revision bone-patellar tendon-bone autograft ACLR after failed primary hamstring tendons autograft ACLR, in the same cohort of patients. However, revision ACLR showed a significantly inferior functional knee outcome compared with primary ACLR. It is important for clinicians to inform and set realistic expectations for patients undergoing revision ACLR. Patients must be aware of the fact that having revision ACLR their knee function will not improve as much as with primary ACLR and the final postoperative functional outcome is inferior.”

Part 3: Returning to sports without surgery. A reality or fantasy?

“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. (10) 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 the 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, ACL reconstruction surgery increases 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.”

Early Return to Play Not Recommended for Student-Athletes – WITHOUT RECONSTRUCTION – More damage to meniscus and cartilage

A November 2021 study in the Progress in Rehabilitation Medicine (11) investigated whether student-athletes with anterior cruciate ligament (ACL) injuries who returned to sports without reconstruction could continue their sporting activities until the end of the season and whether there was an increase in secondary damage associated with knee instability.

How was the study done?

• 288 skeletally mature patients under the age of 25 years old with new-onset isolated primary ACL injuries were included.
• Of these, 20 student-athletes continued playing sports without ACL reconstruction to try to finish the season and were classified as the early return to sports group; the remaining 268 patients, who immediately quit sports and underwent surgery, were classified as the non-early return to sports group.
• Knee symptoms and sporting performance for the rest of the season were assessed for the early return to the sports group. The presence of secondary damage, e.g., meniscus injuries and chondral lesions, associated with instability were compared between the two groups.

Results:

• Fourteen early return to sports-group athletes (70%) indicated that their knees had given way during sporting activities, and seven athletes (35%) were unable to complete the season.
• Despite the early return to sports period being relatively short, medial meniscus tears significantly increased in the early return to sports group, and three patients experienced locking of the medial meniscus and required immediate surgery.

Conclusions:

• Although an early return to sports without reconstruction to complete the season may be a reasonable strategy for ACL injury, patients’ self-estimated performance level was low, and meniscal and cartilage injury rates significantly increased.