Poor prior planning promotes poor performance.

Throughout my career as an orthopaedic surgeon I have witnessed both the conception and evolution of orthopaedic sports medicine as we know it today. I have performed thousands of anterior cruciate ligament (ACL) reconstructions on athletes at all levels of competition—from icons of the professional sports world to my own daughter. Over the years, I have been subject to numerous pitfalls and have seen all of the complications that you can think of and some that you may not have thought possible. My techniques have changed and evolved over years of practice as I have learned from the success and mistakes of others as well as my own mistakes. I share with you a few tips and pearls of wisdom that I have collected along the way to help you avoid and handle the inevitable problems that occur with this procedure and to maximize outcomes for your patients.

First and foremost, never take an ACL reconstruction or any surgical procedure for granted. I do not care how many you have done. You must carry out a meticulous technique, and that begins with preoperative planning in the office, including a thorough physical exam and appropriate diagnostic tests. Attention to detail is extremely important throughout the entire process: preoperative, intraoperative, and postoperative. Intraoperative attention to detail is extremely important because of the many pitfalls associated with the actual surgical technique itself.

When I choose patients for ACL reconstruction, there is no such thing as “always” or “never” and decisions are personalized based on each patient. For me, the decision of who to reconstruct depends more on activity level than age. If a patient is an active athlete at any level of sport, even recreational, he or she is better off having the ACL reconstructed sooner than later. Basically, it is an automatic operation in most cases involving highly active individuals. I have occasionally let a football lineman who is a senior in college delay surgery and braced him until the season is over—but not often. By the way, braces are not always that protective.

The transtibial technique for femoral tunnel drilling has been my routine for some 15–20 years. I continue to use a transtibial technique because I have developed strategies to avoid the pitfalls that can be associated with this method. With these strategies, I can consistently get to an anatomic site for the femoral tunnel, and this has worked well with my patients. A recent review of my own ACL cases showed a revision rate of less than 2% for a study period of over 8 years.

Prehabilitation is extremely important prior to performing any ACL reconstruction. We prefer to get the patient in to see the physical therapist and begin presurgical rehabilitation as soon as possible. The patient needs to be seen daily and treated with ice, compression, and mobilization focusing on the reestablishment of full extension, near normal flexion, and quadriceps tone. The therapist is very important in this stage, as it is unlikely that a patient can carry out the necessary range of motion themselves without some supervision. This does not necessarily mean you have to wait 2 weeks to get their motion back. In some cases, there is not a lot of bleeding and you can get their motion back within a few days. On the other hand, sometimes 2 weeks is not enough, and I have waited as long as 6 weeks. The real pearl here is that there is no rush to surgery. Sometimes it takes a few days, depending on swelling, and other times it may take as long as 6 weeks or more to get the knee ready for a surgical procedure. There should be great cooperation and communication among the surgeon, physical therapists, and athletic trainers working as a team to decide when this patient is ready for a surgical procedure. If there is any question in your mind about an inflamed knee without adequate range of motion, there is certainly no reason to rush—you need to wait.

As far as graft choice is concerned, my gold standard is still an autogenous patellar tendon graft, but the graft choice may change in some situations. If the patient is not super active, I have a tendency to offer a hamstring graft. However, two recent comparative studies have suggested that hamstring grafts have a higher revision rate compared with patellar tendon grafts. In older patients, a nonirradiated allograft is an option if the patient prefers or the situation calls for it; however, I still prefer an autograft. A cohort study in a young active population raised concerns regarding the use of allografts, reporting a four to one failure rate. More recent meta-analysis studies have determined that nonirradiated grafts may perform similarly to autografts; however, concern still remains in active populations. I reserve a nonirradiated allograft for older individuals who need to return to work—not sport—very quickly. The patellar tendon still remains my graft of choice in the majority of cases and the gold standard for an athlete. For a revision case, I still prefer the patellar tendon graft. In this case, I will oftentimes go to the opposite knee and take the patellar tendon graft if the patient’s operative side is not available.

In a graft harvest, you must be very careful when harvesting a patellar tendon graft. There are a number of complications that can arise during graft harvest, and many if not all of these can be avoided. One of these complications is a fractured patella. The incidence of patella fracture while taking a patella tendon graft is about 1 in 900, but it should be 1 in several thousand if you take the graft correctly. Taking a bone plug out of the patella that is too long, particularly in a small hypoplastic patella, increases the risk of fracturing the patella. The bone plug from the patella does not need to be more than 2 cm in length and can be downsized to a centimeter and a half in smaller individuals with a smaller patella. Making cuts that are too deep can also increase the risk of patella fracture. Keeping two to three teeth of a 1-cm oscillating saw visible during vertical cuts will prevent you from cutting too deep into the patella. Gentle use of a small osteotome will free the bone from its donor site. There should be careful attention to the corners and minimal force and prying used during this step. I routinely fill the patellar defect with excess bone from graft preparation. If more bone is needed, a curette can be used to harvest metaphyseal bone through the tibial tubercle harvest site.

By the way, be careful with the presence of an Osgood-Schlatter fragment or Larsen-Johansson fragment off the tibial tubercle or distal pole of the patella. In this situation, you can have a false insertion of the patella tendon with an Osgood-Schlatter fragment fooling you into taking too short of a bone plug. If you do have a bone fragment from one of these syndromes, you can shell out the bone fragment and put that end of the graft deep down into the tibia rather than the femur. Remember, the bending moment of the graft is at the femoral insertion, so you would not want this compromised tissue (where the old Osgood-Schlatter fragment had been removed) subject to this bending moment as it exits the femoral tunnel. You can avoid this problem by putting that portion of the graft down in the tibial tunnel, and you can still use the patella tendon in those cases.

At the start of the arthroscopic portion of the procedure, save time by avoiding the fat pad with the scope trocar. Try starting superior laterally, then sweeping the lateral gutter and into the anterior notch rather than going straight in through an anterior lateral portal and through the fat pad. Sweeping around the edge of the fat pad and pushing it back allows quick visualization so you can move forward with the case and not waste time débriding the fat pad just so you can see. If there is blood in the joint, go immediately to setting up your anterior medial portal, localizing with a needle, staying close to the anterior horn, and orienting an 11 blade horizontally so you do not cut the anterior horn with a vertical blade. After initial photographs of the torn anterior cruciate, immediately start your débridement of the inner condylar notch. Do not try to evaluate the rest of the knee first, because with a bloody effusion it will take you 10 or 15 minutes of doing nothing but washing the blood out just to be able to see. After débridement of the intercondylar notch, you can complete a notchplasty with a large shaver and/or a large burr. By doing this first, you are clearing all the blood in the knee and improving visualization while you are working.

The goal of a notchplasty is twofold. First, it provides adequate visualization of the lateral wall so that you can see to do the procedure. Taking down the anterior lateral border of the notch allows an unobstructed view back to the posterior periosteal sleeve. Second, a notchplasty provides enough room for the ACL graft and prevents impingement throughout the knee range of motion. I start the notchplasty by visualizing the native notch morphology. An A-shaped or narrow notch has been associated with ACL rupture, and turning this into a U shape prevents impingement ( Fig. 32.1 ). With the knee in about 45 degrees of flexion, the apex of the notch is widened to create this U shape and prevent impingement with the knee in full extension. Next, the knee is flexed to about 90 degrees, and 3–5 mm of the lateral notch is removed. This allows my scope to stay in a routine anterior lateral portal throughout the entire procedure, and I can see to the back of the notch to make sure I know where I am putting my femoral tunnel. I do a notchplasty routinely and am more aggressive with the A-shaped notch. After the graft is secured, you need to take the knee out into full extension with your scope in the knee and take a picture to document that you do not have impingement as you go into extension ( Fig. 32.2 ). If the graft does impinge, you need to improve the notchplasty.

Arthroscopic images of three separate right knees showing an A-shaped notch (A) , a U-shaped notch (B) , and a femoral notch after notchplasty (C) .

Arthroscopic image taken after anterior cruciate ligament reconstruction with the knee in full extension with no impingement of the graft on the femoral notch.

Once the notchplasty is complete, I then perform a complete diagnostic arthroscopy, inspecting the articular cartilage and menisci and going through a thorough evaluation with a probe in an ordered fashion—always the same sequence every time. I always look through the notch and evaluate the posterior medial capsule. Placing the knee into slight flexion of about 15 degrees off the edge of the table—not in valgus—put the scope through the anterior lateral portal through the inner condylar notch toward the posterior medial knee. You can then flex the knee up to about 70–80 degrees with the scope through the notch for a full view of the posterior medial joint. Check the posterior capsular attachment for meniscal capsular tear at the back of the medial meniscus. You would be surprised how often that capsule is torn from the back of the medial meniscus with an ACL injury. Using a spinal needle directed anteriorly through a posterior medial approach, probe the posterior capsule, pull it up, and make sure there is no tearing back there. If it is torn, you need to repair it. The repair can be done with an all-inside meniscus suture device.

With that done, you are ready to drill your tunnels. Placement of the tibial tunnel is crucial in order to achieve an anatomic femoral tunnel. The tibial tunnel needs to be relatively shallow and not too vertical. This is done by starting medial to the tubercle, approximately 3 cm distal to the joint line, and aiming laterally. If graft-tunnel mismatch is a concern, the tunnel may be made more shallow or steep. This is most commonly utilized in patients with patella alta, where the graft is excessively long. In this case, the tunnel is drilled more vertically to increase the overall tunnel length. Using a shaver or burr to chamfer the posterior superior portion of the tibial tunnel can aid in reaching more posteriorly on the femur. An adequate notchplasty is key to obtaining an adequate view of the posterior femoral margin. After the notchplasty, the ACL footprint and tunnel location selected are marked with a burr. An acorn-style reamer with a broad head and narrow shaft allows more movement within the tibial tunnel and can be utilized to assist with change of direction and angulation during femoral reaming as necessary. A freehand technique allows the surgeon to change direction as needed to ensure anatomic placement without the restriction of a guidewire and also allows the reamer to follow the posterior cortex up the femur. The femoral tunnel is started in 70 degrees of flexion and is progressively reamed with increasing flexion. This allows an anatomic starting point as well as more horizontal trajectory. Increasing flexion during reaming helps prevent back wall blowout. An external assessment should be performed at the beginning of reaming, and the reamer should be oriented in line and anterior to the femoral shaft ( Fig. 32.3 ).

An intraoperative photograph taken during femoral tunnel drilling via a transtibial technique. An external assessment assures that the reamer remains oriented in line and anterior to the femoral shaft.

Due to the obliquity of the tibial and femoral tunnels, passing and positioning the graft for fixation can be difficult. I use an AO screwdriver through the anteromedial portal to help guide the graft into place by gently tapping it with a mallet until it is seated and appropriately recessed into the femoral tunnel. With the same screwdriver, a notch is made in the femoral tunnel to provide a starting point for the interference screw. This should be tapped and sometimes retapped in younger patients with hard bone.

Once the femoral bone plug is secured with an interference screw, it is time to fix the tibial bone plug. At this point, the leg is placed in extension, the tibia is reduced with a posterior drawer, tension is applied on the tibial side by pulling the passing sutures, and an inference screw is placed posterior to the bone plug. If you put the interference screw anterior, like some do, you are in the short part of the tunnel and are pushing the graft posteriorly as it exits the tibia. Because we are trying to replicate the ligament anatomy, I think the inference screw should be behind the tibial bone plug. This puts the interference screw in a better part of the tunnel and pushes the graft anterior, where it is supposed to be. It is important only to tap enough to get the screw started here. Tapping too far risks cutting the passing sutures and loosing tension.

Document everything that you have done. Take pictures once you finish off the screw in the bone plug up in the femur to document that it is well fixed and you did not violate the back wall. Also, palpate the ACL to make sure that it is tight in extension. It may be slightly looser in flexion, which is the trend nowadays, and that is fine. Always take the scope and look up the tibial drill hole from the outside-in to make sure that your screw is interfaced appropriately and that the bone plug and screw are parallel. You want to see the end of the screw right at the end of the bone plug ( Fig. 32.4 ). While doing this, you can pull the sutures that are still left in to make sure that the bone plug is not loose and is well fixed. Take a picture here as well to verify solid fixation and prove that it is secure.

Arthroscopic images showing interference screw fixation on the femoral (A) and tibial (B) side.

Good documentation can avoid medicolegal issues. It is easy to take pictures at specific steps as you work, and these pictures can save you a lot of headaches. For example, if the patient were to fall down the stairs a week later and the fixation fails, they will swear that you did not put it in correctly. Documentation of a well-fixed graft on both the tibial side and femoral side with a photograph is extremely important. The other thing you want to do at the end of the case is to check your range of motion. Document that you got full extension and full flexion at the end of the procedure so that if a patient develops arthrofibrosis, you have proven in your operative report that you had full range of motion.

I have not used metal interference screws in some 10–15 years. I have had no difficulty using a low-grade biodegradable interference screw that is not highly resorbable. You can also use polyether ether ketone interference screws. The primary reason that I do not like metal interference screws is that you always have to think about a redo. If you have a revision case where there is a metal interference screw deep within the tibial tunnel, it is like looking for a needle in a haystack; you cannot find the screw to get it out and you cannot always drill around it. With metal screws in the femur, even if you can find the screw, you will frequently strip it trying to get it out of the bone if it has been there long enough. Metal screws are really a pitfall and create havoc down the road in redo situations. They also distort magnetic resonance imaging, making preoperative planning difficult. I cannot understand why anyone would want to use metal screws these days.

There has been a movement toward the so-called “anatomic” placement of the femoral tunnel for ACL reconstruction. This requires either drilling through a low anterior medial portal or an outside-in technique with retro-cutting devices. The rise of the use of these methods has presented unique challenges, and a clinical outcome study failed to illustrate a clear benefit with potentially higher revision rates using this technique. One problem with this approach is that it can involve too low misplacement of the tunnel. Young surgeons new to this technique must be conscious of the potential for placing the tunnel too low and too horizontal. Such placement causes impingement on the tibia and replication of the posterolateral bundle alone. This creates a graft that is tight in extension and loose in flexion, and I feel that there has been some increased failure because of this. My goal is to cover primarily the anterior medial footprint. With an oblique tunnel, you can cover part of the posterior lateral footprint as well as the anterior medial footprint. A second problem with this trend involves the lengths of the femoral tunnel. Due to the trajectory and limited bone laterally, you can end up with a short femoral tunnel, which may lead to an issue with graft-tunnel mismatch.

I always use an intra-articular Hemovac drain overnight to try to get as much blood out of the joint as possible. This is removed in physical therapy the next morning. Minimizing postoperative swelling is an important and necessary first step in the rehabilitation process. A hemarthrosis may occur even after removal of the drain, and I am quick to aspirate the hematoma if necessary because swelling in the knee inhibits range of motion and shuts down the quadriceps.

In terms of concomitant injuries, meniscal injuries are the most common; however, the most commonly associated ligamentous injury is an injury to the medial collateral ligament (MCL). With this combination come some specific concerns. If you have an medial collateral ligament (MCL) injury along with the ACL injury, you can have more trouble with swelling and loss of range of motion. If you have a severe MCL injury, you may not have much intra-articular swelling because the bleeding goes out through the grade 3 MCL and into the tissue, and it will look less serious than it really is. The decision on whether to fix an MCL injury depends on several factors. Obviously, the grade of injury is important. For grade 2 injuries, I will generally go ahead and do the ACL surgery when it is appropriate and allow the MCL to heal closed. The timing in this scenario is based on when the knee is ready for the ACL surgery and not so much the MCL injury. I am more aggressive with fixing grade 3 injuries, but this depends on where the MCL is torn. If they are torn distally and retracted out from under the pes tendons or into the joint, I will do a direct repair of the MCL. If you have good physical therapy and control of the patients, you can reconstruct the ACL and repair the MCL in the same setting. This should be done acutely and within the first 10 days and requires special rehabilitation and a motivated patient. Otherwise, you will wind up with a stiff knee.

Thorough rehabilitation and the work of a knowledgeable physical therapist are hugely important after this kind of procedure and may be more important than the surgical procedure itself. There should be an open line of communication between the therapist and the surgeon. They have a lot to teach us and can help identify potential problems before they occur. Key areas you have to be careful with in the rehabilitation process are maintaining an adequate range of motion, immediate and aggressive reactivation of the quadriceps, maintaining passive patellar mobilization, and the prevention of swelling and hematoma formation. The phases of the rehabilitation protocol should be followed in an orderly step-by-step progression. You do not want to get athletes running too quickly, especially if they have a weak quadriceps. If they start early running (particularly when you use a patella tendon autograft), their quadriceps and the patella tendon defect will get overloaded and they will get patellar tendonitis.

For me, getting and maintaining full extension of the knee are the primary goals in the first 2 weeks of rehabilitation. The problem is that when you get behind with extension, it is hard to get it back. If you get behind with flexion, you usually can catch up. So we are much more aggressive with extension. We like to make sure patients are doing prone lying with weight hanging off their ankle over the end of the table as soon as we see them struggling with lack of extension. Because I am concerned about stiffness from day 1, we take multiple measures to attempt to prevent it in the first place. Using an adductor canal block, you block the cutaneous nerves that go to the knee and down the leg, and this helps control patients’ pain, yet they can get their muscles functioning the next morning and start working toward full extension. We start them with early range of motion and use indwelling pain catheters, leaving the blocks in for 2–4 days. It is all comes down to adequate and immediate physical therapy to avoid stiffness.

In order to get athletes back to play, you have to start them off in progressive fashion. You generally start walking on a treadmill and then light running on a treadmill or an altered G machine. If available, have them walk and run on a treadmill underwater in a pool. Once the patient demonstrates good quadriceps strength and passes a thorough clinical evaluation by the therapist, they may progress into a running program. The problem is beginning a running program too quickly. When athletes begin a running program, you need to make sure they do not run up and down steps or run on uneven surfaces. It is a gradual step-by-step process that leads to a real running program. You have to trust your therapist and have a good working relationship with open communication. One of my biggest concerns is returning an athlete too early and having a graft failure.

Histologic studies in humans suggest that the remodeling process of grafts may not be complete until 9–18 months, and the maturation process may continue for 24–48 months. For this reason, I try to refrain from cutting and pivoting as long as the situation allows, with an ideal return to competition at 12 months. The transition of tendon tissue to ligament or ligamentization likely lasts longer than we appreciate. Although we are eager to hasten the rate of ligamentization, currently no clear benefit has been proven with the intra-articular application of platelet rich plasma (PRP) or bone marrow aspirate concentrate at the end of the reconstruction procedure. We have watched with interest animal studies involving biologics and the ACL, and while we do see promise with these studies, there remains much to be learned regarding the biology of ACL healing. There has been a proven benefit regarding patellar tendon harvest. The application of PRP to the site of patellar tendon harvest has been shown to improve healing and decrease donor site morbidity. For this reason, we apply PRP to the graft harvest site just prior to skin closure. Over the past 30 years, orthopaedic advancements in ACL reconstruction have focused on the carpentry of the procedure. The next 30 years will focus on the biology of the injury and improving the biologics of healing. The first great advancement in sports medicine was the arthroscope. I believe that biologic therapy will be the next.