A twist, a pop, a fall to the ground, pain, and immediate swelling…unfortunately, this experience is too common in our young athletes. Anterior Cruciate Ligament (ACL) ruptures cause instability and potentially end sports activity and careers, causing long-term physical and psychological consequences. Is surgery the best option, or is there a self-healing potential for the ACL?
ACL Injury Stats:
More than 200 000 ACL injuries occur in the United States each year. Most occur during athletic activity involving pivoting and cutting sports affecting high school females 4-6x more often than their male counterparts. Most injuries result from non-contact and not a collision with another player. Change of direction (COD) has been identified as the leading cause of ACL tears. A quick turn adds a high load when the knee is flexed, rotated, and abducted. When the foot is planted on the ground, this quick change of direction causes stress on the ACL, and the addition of high-level force can be disastrous.
**The position of the knee during a change of direction is the key to reducing ACL trauma.**
Surgery is Currently the Most Common Treatment:
Approximately 90% of Americans who tear their ACL eventually have surgery, replacing the ACL with a cadaver or using a piece of their infrapatellar or hamstring tendon.
The ACL is the main stabilizer of the knee. An intact ACL is considered essential for athletic activity, especially sports that require pivoting and cutting. It is also thought that the ACL is incapable of healing because of inadequate blood supply. Therefore surgical repair is essential to return to playing high-level sports, and opting not to repair will lead to meniscal tears and early osteoarthritis. Searching the internet will produce site after site that the ACL does NOT have blood supply because the fluid in the knee that allows smooth movement blocks clotting, thus preventing the ability of the ACL to connect and heal. ACL repair is sold as the gold standard enabling the return to play and preventing further meniscal damage and osteoarthritis.
**Research has shown that the outcomes of ACL reconstruction are not as great as we are told, with the increased risk of re-injury and future risk of osteoarthritis.**
Less Commonly Known ACL Surgical Outcomes:
- Only 65% of those who underwent ACL reconstruction returned to their preinjury level. (1,2,3)
- Only 55% of individuals return to competitive sports following surgery. (1,2,3)
- There is a high rate (15x) of retearing the repaired ACL (9%) or the contra ACL (20.5%) within 2 years following ACL reconstruction.
- 25% of athletes (under 25 years of age) who return to high-risk sports go on to have a second ACL injury.
- Expectations for returning to the preinjury sport are often not met.
- High rates of reinjury suggest that there is insufficient neuromuscular training during rehab following ACL reconstruction.
- A 20-year follow-up study on ACL tears found no difference in the amount of osteoarthritis in surgical repairs vs. rehab only.
- Potential surgery side effects: infection, scar tissue, blood clots, kneecap pain, pain/weakness/tendonitis at the graft site (hamstring or patellar tendon), reaction to anesthesia
Surgical outcomes have shown poor odds of returning to play and high incidences of retear.
There is a FALSE ACL surgical narrative….. we need a Paradigm shift & Rethink a rush to ACL Reconstruction.
Non-surgical Outcomes Following a Complete ACL Tear:
Surprisingly 2 and 5 years after an ACL injury, the research found no significant differences in outcomes of ACL surgery versus those that completed a structured rehab program instead of surgical repair. Even more surprising, a twenty-year study found no difference in arthritis between those getting surgery and those doing conservative care.
The anterior cruciate ligament has healing capabilities, and conservative management may provide some athletes with optimal functional outcomes. Unfortunately, very few studies compare surgical reconstruction to rehab alone for ACL tears. The studies did show that long-term results were much better in non-surgical patients.
Return to Play with Complete ACL Tear & NO surgical Repair
But there are instances when a complete ACL tear athletes have returned to play without surgery.
McDaniel and Dameron in 1983, found that after14-years 76% of untreated patients with ACL ruptures returned to strenuous sports. They all had reduced incidences of giving way but continued high rotary instability.
Despite What is Commonly Believed, the ACL has Self-Healing Potential!
Over the years, a few cases of spontaneous healing of complete ACL tears have been reported, but this has not received as much attention as profitable surgery.
Over 50% of ACL tears can heal by themselves with no focused treatment. Research has found that 56% of tears spontaneously heal at 2 years and 58% at 5 years.
Instead of rushing to surgery, the focus should be on the self-healing potential of the ACL!
A fracture requires 6-8 weeks to heal. We have only begun researching ACL healing, so we do not know the amount of time needed and the best position, diet, exercise, etc., that will promote this process. Unfortunately, very few studies have been done, and little is known about what facilitates and what stressors reduce ACL healing other than our plasma is involved.
If over 50% can heal without targeted treatment, then significantly more with improve with proper care. We do not have a protocol for large double-blinded studies. Still, we do have smaller studies and case reports on individuals that were able to return to higher level sport activity without surgery. Initially, the focus is on stabilizing the knee to avoid additional trauma and rotary stress on the injured ligament. This is usually done by bracing and self-awareness by avoiding movements or activities that may harm a newly injured knee. As the weeks pass, the individual will gain confidence and can wean from bracing. We also know that weight bearing is critical for ligamentous healing and maintaining knee integrity. Physical loadings provide an important stimulus for maintaining ligament tissue’s normal structure and function.
Research of Spontaneous ACL Healing
- 1996 Ihara et al. analyzed 50 athletes with acute ACL ruptures treated without surgery using a specially designed brace. Eleven months later, 29 patients showed a continuous ACL on MRI.
- 1996 50 cases of complete rupture after only 3 months of early protected motion 74% of ACL tears showed healing.
- Two case studies were reported (1998) of spontaneous ACL healing. It was found that proximal injuries close to the bone should enhance the healing capability.
- 2001 case study of spontaneous healing of a complete ACL tear after one year.
- 2002 Fujimoto et al. followed 31 patients using an extension block soft brace x 2-3 months. All patients showed healing, 74% were stable at 16 months, and only 8 required surgery because of instability
- 2012 Costa-Paz et al. followed complete ACL tears with no bracing or specific rehab program. They found after 30 months no instability and MRIs, showed end-to-end ACLs, and were able to return to their previous sports activity without bracing and specific rehab parameters.
Surgery: Instead of Replacing – Enhance ACL Healing
There have been exciting new developments in ACL restoration. Unlike ACL reconstruction, which replaces the torn ACL with a graft from the patient or donor, a bridge-enhancer known as BEAR reportedly can heal a torn ligament. The procedure uses an implant containing bovine collagen and the patient’s blood to fill the gap between the torn ends of the ACL to promote healing.
BEAR (Bridge-Enhanced ACL Restoration) procedure uses a new device called the BEAR® Implant, made from purified bovine (cow) collagen, to bridge the ACL stump to the bone using stitches to stimulate restoration. Instead of replacing the torn ligament, this new technique helps the ACL grow back together. Bear is a new procedure and is currently being studied across the nation.
ACL Reconstruction does have a place after all conservative care has failed…BUT, we hope that the promotion of the self-healing potential of the ACL becomes the new gold standard of care instead of ACL replacement.