It all happened so suddenly. You were running down the field and made a quick cut. You heard an audible pop followed by searing knee pain and then collapsed to the ground. Your doctor thinks your tore your ACL and has referred you to a surgeon. What is the Anterior Cruciate Ligament? What is the function of the ACL? Are there different types of ACL injuries? What is ACL surgery? What are the risks associated with ACL surgery? Are there ACL tear treatments without surgery? What are their results and have they been published? Let’s dig in.
What Is the Anterior Cruciate Ligament (ACL)?
The knee has four major ligaments which are illustrated to the right. They include:
- Anterior Cruciate Ligament (ACL)
- Posterior Cruciate Ligament (PCL)
- Medial Collateral Ligament (MCL)
- Lateral Collateral Ligament (LCL)
The Anterior Cruciate Ligament (ACL) extends from the thigh bone (femur) to the shin bone (tibia) and limits forward and rotational movement of the knee. It is a key stabilizer in the knee. It is composed of two separate ligament bundles which include the Anterior Medial and the Posterior Lateral.
What Is the Function of the Anterior Cruciate Ligament?
The ACL is a major stabilizer of the knee that limits forward movement of the Femur on the Tibia (shin-bone)(1). It also restrains rotation of the Tibia.
Are there Different Types of ACL Injuries?
The ACL is the most commonly injured ligament in the body and occurs at an estimated incidence of 200,000 cases per year. However not all ACL tears are the same. It is important to know the specific type of tear. There are three principal types of ligament tears: partial thickness, complete thickness, and complete thickness with retractions
Partial Thickness Tear
This is where a portion of the ligament is torn.
Full Thickness, Non-Retracted Tear
This is a more severe injury. The tear extends across the entire surface of the ligament but the ligament is still held together by small remaining fibers.
Full-Thickness Retracted Tear
This is the worst-case scenario. The tear extends across the entire surface of the ligament and the ligament itself rips apart like a rubber band. The single ACL ligament is ripped apart with two ends that are no longer connected. A full-thickness, retracted ACL tear requires surgery.
What Is ACL Surgery?
ACL surgery is a major surgery that involves cutting out your torn ACL and replacing it with a GRAFT. What is a graft? It is a tissue taken from one site that is used in a different site in the body. The grafts themselves are not ligaments but rather are tendons taken from other areas of the body. There a 4 different types of grafts used in ACL surgery (3). They include:
Hamstring Tendon Graft
The Hamstring is the large muscle in the back of the thigh.
Patellar Tendon Graft:
The Patellar tendon is the large tendon in the front of the knee that connects the knee cap to the shin.
Quadriceps Tendon Graft
The Quadricep is the large muscle in the front of the thigh.
Cadaveric Tendon Graft
A cadaver is an individual that has died but has given permission to use their body tissues for medical use. They may be young or old, female or male.
Note that all the grafts used in ACL surgery are tendons and NOT ligaments.
What Are the Risks Associated with ACL Surgery?
ACL surgery is a major surgery that involves removing the damaged ligament and replacing with a patient’s tendon or cadaveric graft. There are significant risks associated with the surgery that include:
- 66% of teens who undergo ACL surgery will get Arthritis by age 30 (2).
- Compromised positional sense and strength (3).
- Increased risk of graft rupture for patients younger than 20 years of age (4).
- Hamstring atrophy in patients who undergo a hamstring graft (5).
- Knee instability
- Diminished performance. Many professional athletes fail to return to their pre-surgery level of performance. Are there Alternatives to ACL Surgery?
ACL Tear Treatment Without Surgery ?
The Regenexx Percutaneous ACL Repair (Perc-ACLR) procedure is an advanced x-ray guided procedure where a patient’s own bone marrow concentrate which contains stem cells are injected into the damaged/torn ACL. It is a great ACL tear treatment without surgery option. Stem cells are your body’s own powerhouses of healing and can coordinate cells throughout the body to assist in the reorganization and healing of ligament injuries. We have published our results in two peer-reviewed journals (6)(7). MRI images of the ACL prior to and following bone marrow concentrate treatments have demonstrated profound healing. To review pre and post-procedure MRIs please click on the video below.
New Centeno-Schultz Clinic Publication
The Centeno-Schultz Clinic is excited about our newest peer reviewed publication. Publication is part of our commitment to advancing the field of Orthobiologics. We have a large number of publications which sets us apart from other clinics. To see the list of our publications please click here.
Our newest publication is a midterm analysis of patients with ACL tears that underwent x-ray guided injections of bone marrow concentrate and platelets into the ACL tears. Bone Marrow Concentrate is rich in stem cells. 50 patients were randomized into one of two groups: exercise therapy vs treatment group. Patients were 18-65 years of age with MRI evidence of ACL tear and pain or instability despite 3 months of conservative therapy. Pain and function were assessed at baseline and 1, 3, 6, 12 and 24 months. Results: Patients treated with Bone Marrow Concentrate injections had significant improvement in pain and function in comparison to the exercise group. In addition, they had significant improvement in their post treatment MRI scans consistent with healing.
Patients with ACL tears now have a non-surgical treatment option and can avoid the risks and extensive downtime associated with surgery and rehabilitation.
To learn more about non surgical treatment of ACL tears using your own cells, please click on the video below
In Summary
- The Anterior Cruciate Ligament (ACL) is one of four major ligaments in the knee.
- The ACL is a major stabilizer of the knee that limits forward movement of the Femur on the Tibia.
- There are three principal types of ligament tears: partial thickness, complete thickness and complete thickness with retractions.
- ACL surgery is a major surgery that involves cutting out your torn ACL and replacing it with a graft.
- Major risks associated with ACL surgery include early onset knee Arthritis, compromised positional sense, graft rupture, Hamstring shrinkage and knee instability.
- Regenexx Percutaneous ACL repair is an advanced x-ray guided procedure where a patient’s own bone marrow concentrate which contains stem cells are injected into the damaged/torn ACL.
- Our newest peer reviewed publication demonstrated reduction in pain and improved function and post procedure MRI scans in patients treated with bone marrow concentrate in comparison to the controls.
- Regenexx Percutaneous ACL repair is an alternative to ACL surgery and allows patient to avoid the risks associated with surgery.
If you or a loved one has sustained an ACL tear, please schedule a telemedicine consultation. Surgery is associated with long-term risks including graft rupture and then need for future surgeries. Learn from a board certified, fellowship trained physician your nonsurgical, regenerative treatment options.
1.Noyes FR. The function of the human anterior cruciate ligament and analysis of single- and double-bundle graft reconstructions. Sports Health. 2009;1(1):66-75. doi:10.1177/1941738108326980
2.Barenius B, Ponzer S, Shalabi A, Bujak R, Norlén L, Eriksson K. Increased risk of osteoarthritis after anterior cruciate ligament reconstruction: a 14-year follow-up study of a randomized controlled trial. Am J Sports Med. 2014 May;42(5):1049-57. doi: 10.1177/0363546514526139. Epub 2014 Mar 18. PMID: 24644301.
3.Bączkowicz D, Skomudek A. Assessment of neuromuscular control in patients after anterior cruciate ligament reconstruction. Ortop Traumatol Rehabil. 2013 Jun 28;15(3):205-14. doi: 10.5604/15093492.1058410. PMID: 23897997.
4.Webster KE, Feller JA, Leigh WB, Richmond AK. Younger patients are at increased risk for graft rupture and contralateral injury after anterior cruciate ligament reconstruction. Am J Sports Med. 2014 Mar;42(3):641-7. doi: 10.1177/0363546513517540. Epub 2014 Jan 22. PMID: 24451111.
5. Snow BJ, Wilcox JJ, Burks RT, Greis PE. Evaluation of muscle size and fatty infiltration with MRI nine to eleven years following hamstring harvest for ACL reconstruction. J Bone Joint Surg Am. 2012 Jul 18;94(14):1274-82. doi: 10.2106/JBJS.K.00692. PMID: 22810397.
6. Centeno C, Markle J, Dodson E, et al. Symptomatic anterior cruciate ligament tears treated with percutaneous injection of autologous bone marrow concentrate and platelet products: a non-controlled registry study. J Transl Med. 2018;16(1):246. doi: 10.1186/s12967-018-1623-3.
7.Centeno CJ, Pitts J, Al-Sayegh H, Freeman MD. Anterior cruciate ligament tears treated with percutaneous injection of autologous bone marrow nucleated cells: a case series. J Pain Res. 2015;8:437-47. doi: 10.2147/JPR.S86244.