Ligament Laxity Leads To Worse ACL Reconstruction Outcomes

I was involved with a recent MOON (Multi-center Orthopaedic Outcomes Network) study that demonstrates that patients with loose ligaments and hyperextension have worse results and more frequent graft failures. Read details HERE

Why Revision ACL Grafts Are Chosen For Patients

Revision ACL grafts are chosen for a variety of reasons. Read our MARS study HERE to see the most important factors (Hint- It's the surgeon you choose)

MOON-MARS Revision ACL Graft Study Presented Toronto AOSSM Meeting

A combined MOON (Multi-Center Orthopaedic Outcomes Network)- MARS (Multi-Center ACL Revision Study) looked at patellofemoral (kneecap) cartilage changes after allograft or autograft primary ACL reconstruction as identified at the time of revision ACL reconstruction. This study presented by Robert Magnussen of Ohio St. at the Toronto AOSSM (American Orthopaedic Society for Sports Medicine) meeting in July. 134 patients had undergone MOON primary ACL reconstruction followed by MARS revision ACL reconstruction. Progression was identified as progression of one grade worse or a 25% increase in size of the lesion. 31 (23%) had worsening progression of arthritis. Results showed allografts had a 15.5 times higher risk of progression. Odds also increased 10% with each unit increase of BMI. Age, sex, activity level, meniscus status, injury mechanism had no impact. The association between graft choice and damage was surprising. Previously it was thought maybe a patellar tendon (BTB) autograft might be at more riskk. Allografts with more laxity may place more pressure on cartilage, but we cannot be sure. Further work will be necessary to sort this out.

MOON ACL Reconstruction Award Winning Study

At the AOSSM Annual Meeting the 10 year outcomes for the MOON Group were presented by Kurt Spindler MD. The study won the AOSSM O'Donoghue Award for best clinical study for 2017. The MOON Group is a 7 site study focusing on primary ACL reconstructions. 

Findings in this study of 1592 ACL reconstructions with 83% follow up showed several factors impacting the IKDC and KOOS Sports and Recreation and KOOS Quality of Life with worse scores. These included: Grade 3 and 4 cartilage wear in any compartment, previous medial meniscectomy, revision ACL reconstruction, higher BMI, smoking, reoperation or subsequent surgery and lower baseline scores. Factors not predicting worse scores included surgeon, medial and lateral meniscus surgery, sport played, graft chosen, MCL or LCL injury or higher laxity.

Factors that predicted worse Marx score can be seen in this slide. These findings can be used to better predict outcome and counsel patients as to expectations for ACL reconstruction.

Predictors of Outcome from the MARS Cohort: Surgical Factors

Revision ACL Reconstruction Predictors of Outcome: Graft Choice

ACL Reconstruction Graft Choice in Young Athletes

Anterior cruciate ligament (ACL) injuries currently require a reconstruction for active individuals desiring to return to activities that involve planting, cutting, turning, twisting or jumping. A reconstruction simply means a replacement of the ACL since repair currently does not work (see this link for exciting news regarding ACL repair). As part of the reconstruction a graft must be chosen and used. There are several options available, but young athletes and their families need to be careful in their graft decision process. Certain graft choices may not be the best for younger patients.

Broadly, there are two categories of graft: 1.) allograft (cadaver) and 2.) autograft (patient’s own tissue). There are advantages and disadvantages for both types. Allograft offers the advantage of no need to obtain a graft from the patient which may mean less pain and a quicker recovery. Unfortunately, the disadvantages include risk of disease transmission (HIV and Hepatitis 1/1,000,000), slower graft incorporation and a higher rerupture/failure rate. In an important study by the Multi-center Orthopaedic Outcomes Network (MOON) Group that we participated in at Washington University as an original MOON Group site cadaver grafts were noted to have a 4 times higher failure rate vs. autografts for patients of the same age and activity level. For example a 16 year old female high school team sport athlete has an ~5% ACL autograft failure rate in the first 2 years after surgery and ~20% failure rate over the same time period for an allograft. Read the study here: (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3445196/) Obviously, that is a rate of failure unacceptable for young athletes. Conversely, in a patient over the age of 40 the failure rate remains 4 times higher, but at 2% vs. 0.5% the relative risk is very close and allograft may be a reasonable choice for an older adult patient.

This has been confirmed also in the revision (redo) ACL reconstruction setting with a 2.78 times higher failure rate for allografts noted by a study performed by the Washington University coordinated MARS Group. Read the study here: (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4447184/ )

There are 2 types of autografts commonly used: hamstring or patellar tendon. Both have advantages

 and disadvantages. Hamstring grafts have a lower risk of kneeling pain, but less strong initial fixation and typically are ~1mm looser once healing is complete. Patellar tendon grafts have stronger initial fixation, heal a little tighter, but have a higher risk of kneeling pain. Data from Europe suggest the hamstring grafts may have a slightly higher (0.5—1.0%) risk of rupture, but this has not been duplicated in the US in similar studies. I typically recommend patients let their surgeons use the graft with which they are most comfortable. The small differences in the grafts typically do not matter clinically.

ACL Reconstruction Rehabilitation Part 3

Postoperative rehabilitation remains critical to the outcome for the patient undergoing ACL reconstruction. If the physical therapy following surgery does not go well then it does not matter how well the surgery was performed. When the

MOON group began enrolling ACL reconstruction patients we decided to develop a standardized physical therapy protocol to use for our patients and to have consistency for our patients’ recovery. I was tasked with developing an evidence based review of ACL reconstruction rehabilitation and then using it in conjunction with our physical therapists to develop a practical protocol. Ultimately, we developed what has been a very popular protocol that is more milestone based than time based and has been easy to implement across our several sites. We have subsequently published the protocol in the AOSSM journal Sports Health so that others can utilize it also. You can read the description and find the protocol HERE.

We based the protocol on a series of Systematic Reviews we performed to establish the evidence for best practice ACL rehabilitation. Previously we discussed the first 2 reviews. Here we will review the findings in our 3rd review which was an update of the original 2. It can be found HERE. In this study we discussed an additional study evaluating the use of Continuous Passive Motion machines which once again showed no advantage. Several additional studies had been published evaluating bracing and none demonstrated any advantage in the postoperative rehabilitation period. Additional studies evaluated early ROM and quad strengthening without any increase in laxity. Eccentric strengthening was safe and showed improved strength gains compared to concentric strengthening when initiated at 3 weeks and continuing for 12 weeks. Accelerated rehab shortening to 5 months the recovery did not result in worse outcomes  or safety issues. Additional electrical stimulation studies showed safety, but no significant efficacy in ACL rehabilitation.

Most additional studies performed since our last review reiterated our additional findings. I will be presenting specific findings for revision ACL reconstruction rehabilitation at the July 2016 American Orthopaedic Society for Sports Medicine and we will blog those results when available next week.

Revision ACL Reconstruction Graft Choice Part 2

Revision ACL reconstruction Graft choice is an important Issue that impacts patient outcome.  In the AOSSM O'Donoghue award winning study published in American Journal of Sports medicine the MARS group analyzed the impact of allograft versus autograft choice on patient reported outcomes, reoperation and return to sports.Read the full study HERE In this study of 1205 patients that underwent revision anterior cruciate ligament reconstruction at 52 sites by 83 different surgeons 58% were male, median age was 26.  48% underwent autograft reconstruction and 49% underwent allograft reconstruction.  3% had a combination.  We obtained followup on 989 with questionnaires (82%) and an additional 10% phone followup for a total of 92% followup At 2 years. The IKDC Sports score improved with the use of autograft with an odds ratio of 1.33. The Knee Osteoarthritis

Outcome Score subscales sports and recreation and quality of life improved with autograft use with an odds ratio of 1.33.  37/1112 (3.3%) patients sustained a graft rerupture. Use of an autograft resulted in a 2.78 times less risk for graft rerupture.  Graft irradiation versus nonirradiated grafts did not affect the allograft failure rate.  More grafts had not undergone a radiation that ultimately failed.  Many people previously had believed that if the graft had not undergone irradiation then the results were equal to autograft. Reoperation risk was not affected by allograft versus autograft use.

Based on these findings many people now recommend if at all possible using an autograft for revision anterior cruciate ligament reconstruction.  This can involve the quadriceps, patellar tendon or hamstring grafts.  Frequently I will use a graft from the opposite knee if no other autograft options remain. 

Revision ACL Reconstruction Graft Choice Part 1

Revision ACL reconstruction requires careful thought about the appropriate graft to utilize.  In the revision (redo) situation a previous graft has already been used and failed.  This can force surgeons to potentially use a graft that is not their first choice.  As the basis for the MARS (Multicenter ACL Revision Study) we allowed surgeons to choose their graft that they felt most appropriate in the clinical situation.  Many surgeons believed that graft choice was a fait accompli and that they had no real choice in the matter.  They were forced to many times use a graft not of their choice based on other factors including patient's age, patient’s sport, previous graft utilized, gender etc. In a propensity study the MARS Group performed (Accepted for publication in The Journal of Knee Surgery) we analyzed a variety of factors that impacted revision ACL graft choice. Below you can see the factors analyzed and their impact on what graft the patient eventually received.

As can be seen despite a variety of factors that impact graft choice the most important factor was the particular surgeon that treated you.  Thus, a surgeon that wants to use an allograft (cadaver) for the reconstruction can do that.  Likewise, a surgeon that wants to utilize an autograft has the ability to control that decision most of the time.  The top 5 choices are expanded below and as can be seen in this table ---in fact the particular surgeon involved was 5 times higher impact on graft choice than anything else analyzed including the previous graft the patient had utilized for the primary ACL reconstruction.

Following this study we knew that if we could improve what type of graft gave the best results we could then recommend to surgeons to use that graft and impact patient outcomes.  In Part 2 I will discuss the follow-up study that analyzed outcomes depending on the patient's graft utilized in the MARS study.

ACL Injuries

The anterior cruciate ligament (ACL) is one of the four main ligaments of the knee. It is the primary restraint that provides rotational stability to the joint. It is often injured during cutting, twisting, jumping, change of direction or pivoting-type maneuvers. In addition, it is often associated with meniscal or articular cartilage injuries in greater than 50% of patients. Females are up to 3-6 times more likely to be injured than males, given the same athletic performance. Once the ACL tears, it is not able to heal itself. Repair of the torn ends does not work either. Anterior cruciate ligament reconstruction is one of the most common operations performed in orthopaedic sports medicine with more than 200,000 reconstructions performed in the U.S. annually.

Treatment options consist of either conservative (non-surgical) or surgical treatment. Conservative treatment involves modification of those activities that involve cutting, twisting, jumping, or pivoting. In-line activities can typically be resumed once pain and swelling subsides. A physician may prescribe anti-inflammatory medication and physical therapy to regain normal knee motion and strength. Bracing may also be prescribed for certain at-risk activities. Some patients may be willing to reduce or eliminate those activities that may cause instability episodes.

Surgical treatment consists of reconstruction of the ligament as its direct repair is not feasible due to the inability of the torn ligament to heal. This surgery involves the placement of a reconstructive graft taken from the patient’s knee’s patellar tendon (the tendon located beneath the knee cap) or from the hamstring tendons. Alternatively, your surgeon may choose to use a donor graft, known as an allograft, to reconstruct the ACL. The surgery itself takes approximately one hour and is performed on an out-patient basis with less than 1% percent risk of complications. Allograft reconstruction is not advised for younger, active patients.

Extensive physical therapy is required for a successful recovery from ACL reconstructive surgery. It is necessary following the surgery in order to regain full knee motion and strength, and to return to athletic activity. Most patients are able to return to play following ACL reconstruction approximately 6 months postoperatively. The overall success rate of ACL reconstruction using present-day surgical techniques is well over 90%.

Future posts will give additional detail regarding the treatment and outcome of these injuries.