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Non-Surgical Treatment Options for Partial ACL Tears

| | ACL, Knee

Injuries to ACL are life-changing as witnessed by professional athletes who fail to return to high-level play after ACL surgery. The frequency of anterior cruciate ligament (ACL) injuries (aka “partial ACL tears”) are increasing and an estimated 150,000 ACL reconstructions performed per year in the United States (1).

What is the ACL?

The Anterior Cruciate Ligament (ACL) is a key ligament in the knee that resists forward movement and rotation and as such is a key stabilizer.

There are three distinct types of ACL tears which are illustrated below.

A partial tear involves only a portion of the ligament.

A complete tear involves the entire ligament but the fibers are contiguous.

A complete with retractions occur when the tear involves the entire ligament and the ligament fibers are pulled apart.  This is similar to when a rubber band breaks.

Do partial ACL tears require surgery?

Orthopedic surgeons have advocated surgical repair of partial-thickness ACL tears for the following reasons (2):

  • many partial-thickness tears progress to complete tears with possible injury to cartilage and meniscus.
  • partial-thickness tears by led to degeneration lesions within the ACL

Not everyone, however, is an agreement with this surgical statement.  Is there evidence to prove otherwise?

Want to Get Back to What You Love, Without Surgery and Medication?

Can partial-thickness ACL tears heal?

Yes!  A recent study demonstrated that the healing of partial-thickness ACL tears is possible (3).  121 young active adults were randomized to two different treatment protocols.  Both groups underwent a structured rehabilitation program.  One group underwent ACL reconstruction with 10 weeks of the injury.  The other group delayed ACL reconstruction unit it became obvious that they needed it or until it healed.  At the two-year follow-up, both groups had good results.  Neither treatment was better than the other.  Most importantly, 60% of those who delayed surgery found that they never needed the surgery.

Pujol in a systematic review of the literature review demonstrated that the partial ACL tears could have a favorable outcome without surgery if sports activity was limited(4).

Can injections heal partial thickness ACL tears?  Yes!!

We have published our results in peer review journals; The first study in 2015  was a prospective study that followed a small group of patients with ACL tears. After precise x-ray guided stem cell injections, seven of the ten patients noted clinical improvement along with MRI improvement of ACL tears.(5)

Our second study in 2018 involved 29 patients with ACL tears.  All patients underwent bone marrow stem cell injections and then followed for 24 months.  Subjective clinical outcome measures including numeric pain scale(NPS)  and lower extremity functional scale( LEFS).  Pre and post-MRI images fo the ACL tear underwent objective quantitative analysis. 79% of patients had significant improvement in ACL signal on MRI.   72% of patients noted clinical improvement at 23 months on patient self-reporting outcome measures listed above(6).

Injection of stem cells into a torn ACL is a challenging procedure and we pioneered and mastered the technique.  Below is an x-ray image of contrast being injected into the ACL.  The ACL is delineated by the black dotted line that stretches from the back of the knee to the front.

Watch the Regenexx stem cell ACL procedure in the video below.

Key Point

Partial-thickness ACL tears can be effectively treated without surgery.  Precise injections of bone marrow stem cells are an effective nonsurgical treatment option for partial-thickness tears of the ACL.  This allows one to avoid surgery and the numerous complications associated with ACL surgery.  Centeno-Schultz Clinic pioneered orthopedic stem cell injections and the techniques for successfully healing of partial tears of the ACL.  If you or a loved one has sustained an ACL tear please schedule an appointment to discuss candidacy for stem cell therapy.  Anything less will jeopardize the outcome.


  1. Whitehead TS. Failure of anterior cruciate ligament reconstruction.Clin Sports Med. 2013;32(1):177-204.DOI: 10.1016/j.csm.2012.08.015
  2. Temponi EF, de Carvalho Júnior LH, Sonnery-Cottet B, Chambat P. Partial tearing of the anterior cruciate ligament: diagnosis and treatment.Rev Bras Ortop. 2015;50(1):9-15.DOI: 10.1016/j.rboe.2015.02.003
  3. Frobell RB, Roos HP, Roos EM, Roemer FW, Ranstam J, Lohmander LS. Treatment for acute anterior cruciate ligament tear: five year outcome of randomised trial.Br J Sports Med. 2015;49(10):700.DOI: 10.1136/bmj.f232
  4. Pujol N, Colombet P, Cucurulo T, et al. Natural history of partial anterior cruciate ligament tears: a systematic literature review.Orthop Traumatol Surg Res. 2012;98(8 Suppl):S160-4.DOI: 10.1016/j.otsr.2012.09.013
  5. 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
  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


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