Issue: July 2017
July 14, 2017
9 min read

Patients who never make it back after ACL injury present opportunities, challenges

Issue: July 2017
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In a 2015 publication, the American Orthopaedic Society for Sports Medicine reported 100,000 to 250,000 ACL ruptures occur annually, and most occur during sporting activities, such as basketball, soccer, skiing and football. Despite advances in ACL surgery, some patients never make it back to sport or usual function. This can be due to technical failure with the treatment or other circumstances, sources told Orthopedics Today.

“Unfortunately, ACL failures occurmore often than we like,” Brett D. Owens, MD, professor of orthopedic surgery at Brown University Alpert School of Medicine, said. “Data from the [Multicenter Orthopaedic Outcomes Network] MOON group suggest the graft retear rate is as high as 5%. Depending on how you choose to define failure can affect how many ‘fail,’ and we are learning many young athletes never return to their previous level of sporting activity.”

The definition of successful return to sport or usual function following ACL injry and surgery differs depending on the overall goals of the surgeon and the patient.

Darren L. Johnson, MD
Darren L. Johnson, MD, said patients who reach 2 years post-ACL injury have a significantly decreased risk of a second ACL tear or a contralateral injury.

Image: Patsy S. VanHoose

“For some [patients], getting back to any activity may be successful and for others, not getting back to the same level of activity they would hope to would be a less optimal result,” David C. Flanigan, MD, of the Jameson Crane Sports Medicine Institute at the Ohio State University Wexner Medical Center, told Orthopedics Today.

Definition of return to sport

Lynn Snyder-Mackler, PT, ATC, ScD, SCS, FAPTA
Lynn Snyder-Mackler

A survey in the British Journal of Sports Medicine in 2015 that Lynn Snyder-Mackler, PT, ATC, ScD, SCS, FAPTA, and colleagues conducted showed orthopedic and sports physical therapists and sports orthopedic surgeons in Europe and the United States universally define success with ACL treatment as patients “returning to their previous sport at the same level and no reinjury.”

“Not returning is not necessarily failure, but success is returning to sport at the same level and no reinjury,” Snyder-Mackler, who is Alumni Distinguished Professor and Francis Alison Professor in the Department of Physical Therapy at the University of Delaware, told Orthopedics Today.

However, patients sometimes have a higher expectation of what they may be able to accomplish after surgery, which sources said may be a somewhat unrealistic expectation.

According to Robert A. Arciero, MD, professor of orthopedics at the UConn Health Center, studies have shown there is a return-to-play rate of about 63% to 65% for professional football players after ACL injury and related treatment.


This is lower than public perception, he noted.

The percent of return to play after ACL injury “in high school-aged kids, [is] somewhere in the mid- to high-80s,” Arciero said. “In major league soccer, it is somewhere between 70% and 85%.”

Sources noted that returning patients to the same level of performance they had prior to their ACL injury is never a sure thing and many patients may never return to the 100% level of function.

“It takes about 2 years for the hardwiring — that connection of your central nervous system and your balance and your proprioception — to sort of reconnect,” Darren L. Johnson, MD, professor and chair of Orthopedic Surgery at the University of Kentucky, told Orthopedics Today.

Patients who manage to reach 2 years postoperatively without reinjury experience a decrease in the risk of reinjury, he noted.

“If [patients] can make it through those first 2 years, they have not reinjured [their ACL], they have not torn their meniscus again, they have not had further surgery and they made it 2 full years since their surgery, then they significantly change what risk [category] they are in,” said Johnson, who is an Orthopedics Today Editorial Board member.

Technical errors are possible

According to data from the Multicenter ACL Revision Study or MARS group, failure of ACL surgery due to technical error occurs in 60% of patients. Furthermore, concomitant injuries may predispose a patient to surgical failure, Owens said.

Brett D. Owens, MD
Brett D. Owens

“Surgeons assessing patients with a failed ACL need to perform a comprehensive assessment of the patient and determine the cause for failure,” he said. “The cause may not be clear or may be multifactorial. The revision surgeon must rule out concomitant injuries or malalignment issues that predispose the patient to ACL failure.”

Damage to the articular cartilage or menisci, in addition to an ACL injury, can be a factor in patients not returning to normal function, sources told Orthopedics Today.

“The ACL injury is usually what gets most of the attention, but those frequently come with damage to the menisci, which are the shock absorbers to the knee. It often comes with damage to the articular cartilage, the delicate lining to your bones. It can come with damage to other ligaments and if [patients] have what we call a complex injury where [they] have a meniscus tear plus maybe a defect on the surface, that is not the same thing as an isolated ACL where the surfaces and the menisci are normal,” Edward M. Wojtys, MD, told Orthopedics Today.


Arciero said a knee that is unstable after surgery will also cause problems and affect return to sport.

“The actual failure rate of the surgery, where we fail to stabilize the knee or [the patient has] an early re-injury, is somewhere nationally quoted between 5% and 10%,” he said.

Graft choice may affect outcome

Edward M. Wojtys, MD
Edward M. Wojtys

The type of graft used in ACL surgery may help minimize problems and maximize a patient’s chance of returning to full activity with a good result, according to Wojtys, who is professor of orthopedics at the University of Michigan and editor of Sports Health Journal.

“Allografts are known to have a higher failure rate than autografts,” Owens said. “Older patients are at lower risk of retear, in general, and may be able to tolerate this increased risk, but young athletes will push their knee to its limits and cannot handle that risk,” he said.

Although the results of comparisons of different autograft options are unclear, many surgeons select patellar tendon autograft for ACL reconstruction in high-risk young athletes, Owens noted.

“If you are looking at skeletally mature high school, collegiate athletes, I think most of us would agree using [the patient’s] own tendon gives you the best chance at return to play and having a more stable knee on objective testing and a longer duration of that graft working before it retears, particularly in females,” Johnson said.

According to Arciero, reconstructing the patient’s injured ACL with his or her own graft also has been shown to provide better results compared with a donor graft, especially in young athletes.

Robert A. Arciero, MD
Robert A. Arciero

“At least in young athletes, there is some strong evidence the surgery should be done using the patient’s own tissue, not a donor graft,” he said. “Donor grafts have a higher risk of failure in young people.”

In addition to choosing the best graft, Arciero told Orthopedics Today surgeons must also be sure to accurately place the graft.

“The ACL needs to be put in the area that the normal ACL lives,” Arciero said. “Not everybody can settle on exactly where that area is, but [an] adequate piece of tissue needs to be put where the ACL was, in order for it to heal. If we deviate from that, if [the surgeon puts] the graft 5 mm to 10 mm away from this area, [they are] going to get a failure.”


Rehabilitation to regain function

Rehabilitation can be as critical as the surgery for returning patients to usual function, according to Johnson.

“Not doing the rehabilitation will increase the odds of failure,” Arciero said. “In other words, regaining normal motion, regaining normal strength and regaining normal plyometric ability, balance, coordination, jumping, stopping skills, those things all have to happen for the ACL [surgery] to be successful.”

Snyder-Mackler noted rehabilitation is performed in two stages after surgery. The first stage involves resolving any impairment by re-establishing the patient’s range of motion, reducing knee swelling and helping the patient walk without a limp.

“Then, getting more strength, moving more normally and then stressing them over and over in different kinds of situations ultimately trying to mimic situations they might be faced with when they return to play,” is the second stage of rehabilitation, she said.

Patients should avoid delaying the start of rehabilitation after ACL surgery because that may negatively affect the overall surgical outcome, Snyder-Mackler added.

“Delayed physical therapy, delayed muscle activation, delayed achieving normal range of motion: those things work in a negative way for the final result,” Arciero said.

According to Flanigan, the care and expertise of a physical therapist help motivate patients to make progress at the correct pace.

David C. Flanigan, MD
David C. Flanigan

“[Patients] have at their disposal other modalities which can help with, not only swelling control, but also with getting their muscle activation back quicker with the use of electrostimulation machines,” Flanigan told Orthopedics Today.

However, the ability for patients to rehabilitate postoperatively varies considerably and not all patients have the same rehabilitation potential. Wojtys said patients who struggle with preoperative rehabilitation will also likely struggle with postoperative rehabilitation.

“Many athletes are motivated and they find it easy to exercise and so they may be at the top of the list in terms of their rehab potential,” Wojtys said. “But there are a lot of people who do not fit in that category, who are not used to pushing themselves, are not used to exercising every day, are not used to pushing through difficulties and months of hard work. For those people, [rehabilitation] is a challenge. If you are unable to do the rehab necessary to recover from an ACL surgery, most likely you will not get back to the same level of participation,” he said.

Fear of reinjury is real

Research has shown kinesiophobia, or the fear of reinjury, and pain catastrophizing may also hinder a patient’s recovery after ACL injury.


“A big component for a lot of patients for not getting back is they have a fear they are going to reinjure their knee or, if they go through a certain movement, they are going to put their knee at risk and reinjure it,” Flanigan said. “That is almost like a mental hurdle they cannot get through [so that they can] get back toward sport.”

According to Snyder-Mackler, a patient’s fear of reinjury should not be taken lightly.

“About one-third of young active patients who return to sport either tear their graft or tear their other ACL,” she said.

Patients who experience kinesiophobia and pain catastrophizing can learn coping techniques from a sports psychologist and can receive help with proprioception and movement patterns from a physical therapist, Flanigan said. Therapy can help patients who have a successful surgery, but it can also help patients who are struggling to get back to the level they would like to be, he added.

“Everyone is different. Their timeline to get back toward full recovery may not be the timeline they want,” Flanigan said. “Their body may take 1 year [or] longer for them to go through these phases of rehabilitation to where they feel comfortable that they can get back toward an active lifestyle.”

Modes of Graft Failure

Not interested in returning to play

More simply, some patients find their lives are too busy to continue in recreational sports. High school and collegiate athletes tend to want to return to the same or higher level of activity after an ACL injury and surgery compared with recreational athletes who are aged 40 years to 50 years, according to Wojtys.

“The older you are, the more likely [you] do not have the opportunity to play anymore,” Snyder-Mackler said. “For example, you graduated from high school and you were never good enough to play in college. You have run out of opportunity to play that sport again or life gets in the way.”

Counseling patients

Prior to surgery, surgeons should counsel their patients on the possibility of failure or not being able to get back to their full level of activity.

“I counsel patients on the reported failure rates, as well as the most common reasons for failure, and offer a comprehensive approach to their knee,” Owens, who is an Orthopedics Today Editorial Board member, said. “We then select the most appropriate surgical approach and timing based upon our exam and imaging findings and the patient’s desires and timing concerns,” he said.


According to Owens, the success of any given ACL reconstruction surgery falls heavily on the decisions made by the surgeon before, during and after surgery.

“The surgeon is the only person who can control the decision-making in the OR — and that is the primary focus,” Owens said. “Ensuring adequate rehabilitation and determining the optimal timing of surgery, selecting the appropriate graft, performing a thorough examination under anesthesia and diagnostic arthroscopy, and addressing any concomitant pathology, drilling anatomic tunnels and ensuring secure graft fixation — these are in the control of only the surgeon.” – by Casey Tingle

Disclosures: Owens reports he is a paid consultant for Mitek and Conmed/MTF. Wojtys reports he receives grants from the NIH, is a co-chair of orthopedic research for the NFL and is the editor of Sports Health Journal. Arciero, Flanigan, Johnson and Snyder-Mackler report no relevant financial disclosures.

Click here to read the POINTCOUNTER, “What criteria should patients meet before returning to pivoting sports after ACL surgery?