Sports medicine

In an exclusive interview for Middle East Health, Elizabeth Nolan speaks to Dr Charles Brown, a pioneer in the development of minimally invasive, anterior cruciate ligament (ACL) surgery and hamstring ACL reconstruction, about the pervasiveness of ACL injuries in the GCC, as well as the latest techniques in prevention, diagnosis and treatment.

Dr Charles H Brown, Jr is director of the Sports Medicine Knee Service at Brigham and Women’s Hospital in Boston, USA. He is also a clinical instructor in Orthopaedic Surgery at Harvard Medical School. A pioneer in the development of minimally invasive, anterior cruciate ligament (ACL) surgery and hamstring ACL reconstruction, Dr Brown has devoted his career to achieving a better understanding of the biomechanics of ACL replacement grafts, ACL graft fixation methods, and the development of new surgical techniques in the treatment of common knee sports injuries. Recently named “Top Doctor for Sports Medicine” by Boston Magazine, Dr Brown lectures and performs surgery internationally. In 2001, he and his colleague Dr. Nader Darwich co-founded the Knee Injury Service at Zayed Military Hospital in Abu Dhabi, and subsequently developed the first cadaveric tissue bank in the GCC.

Elizabeth Nolan: It’s widely known that the Anterior Cruciate Ligament (ACL) is one of the most common sports injuries that results in reconstructive knee surgery. Even so, the Knee Injury Service at Zayed Military Hospital has performed over 300 ACL reconstructions within the past four years. Why is the incidence of ACL injury so high in the Middle East?

Charles Brown: That’s an excellent question. In North America we know that the incidence of ACL injuries is approximately 1 per 3,000 people. Although the exact incidence in the UAE and other GCC countries is unknown, based upon my experience, I suspect that it is much higher. There are several possible explanations for this – some have to do with external factors, and some with anatomical factors. External factors which have been implicated include: the individual’s muscle strength, his ability to balance, and the playing surface. Possible anatomical factors include: joint looseness, leg alignment, the size and strength of the ACL, and the size of the cavity which surrounds the ACL.

EN: Please describe how the minimally invasive technique you perform differs from the open ACL surgical procedures of the past?

CB: Prior to 1986, the standard practice was to perform ACL reconstructive surgery through large, open incisions in the knee. This technique resulted in significant postoperative pain and scar tissue. Loss of motion, stiffness, and muscle weakness were common, and the recovery was slow and unpredictable. The introduction of arthroscopic techniques, also known as minimally invasive surgery, has revolutionised the treatment of knee injuries. The advantage of using an arthroscope to perform surgery is that it avoids making large, painful incisions, avoids cutting muscles and nerves, and permits better visualisation of the internal structures of the knee. In the United States ACL surgery is usually performed as a day case. All patients experience shorter, less painful recovery periods as a result of these new surgical techniques, but for athletic patients, the benefits are that much greater – it’s all about getting back in the game as quickly and safely as possible.

EN: Your “surgical home” is Brigham and Women’s Hospital in Boston. Yet you’re also a visiting orthopaedic surgeon at Zayed Military Hospital. What initially brought you to Abu Dhabi?

CB: In 1996, I gave several presentations at the GCC Orthopaedic Conference. Not long after that I was invited by the Directorate of Medical Services for the UAE Military to establish a Knee Injury Service at Zayed Military Hospital. As a result of the programme’s success, we are now treating private patients as well, including players from many of the UAE sports clubs.

EN: Locally and globally, which sports are most conducive to non-contact ACL injuries?

CB: Any sport that requires jumping, twisting or suddenly changing direction can lead to an ACL injury. In the UAE and other GCC countries, football is the primary culprit – players frequently twist or hyperextend their knees. Internationally, handball, skiing, gymnastics, rugby, lacrosse and basketball are all sports associated with a high incidence of ACL injuries.

EN: How do you diagnose an ACL tear?

CB: You begin by asking the player to describe how the knee was injured. The majority of the time, the patient will describe a noncontact injury, involving twisting, deceleration, or hyperextension. In about two-thirds of cases, the player will feel or hear a “pop” at the time of the injury. The knee may buckle or collapse entirely, and the player falls to the ground in pain. Following the injury, there is usually swelling in the knee joint within the first 24 hours. After listening to the patient’s story, examine the knee and look for swelling as well as abnormal translation between the tibia and femur. Since the ACL is a fibrous structure, X-rays of the injured knee are usually normal. The most reliable test for detecting damage to the ACL is Magnetic Resource Imaging, which is about 95% accurate. However, accuracy rates for an experienced clinician have been reported to be in the 90% to 95% range.

EN: How would you describe an appropriate candidate for ACL surgery?

CB: Because the ACL is so important for playing sports, most of my patients are young, athletic people who want to continue playing sports or living an active lifestyle. With the introduction of arthroscopic surgical techniques, which have minimised surgical morbidity, the patient’s age is no longer an issue. We can operate on young and old alike.

EN: You’ve written that the current success rate for ACL surgery is greater than 90%. Exactly how do you define success?

CB: Objectively speaking, a successful outcome is defined as restoring normal translation and rotation between the tibia and femur, and re-establishing a normal range of motion, with no pain or swelling in the joint. Subjectively, success is defined by returning the patient back to the level of activity that they had prior to the injury without symptoms. A successful outcome depends on proper place of the ACL graft, rigid graft fixation, and a well structured postoperative rehabilitation programme. Ultimately, however, success depends almost as much upon a motivated, compliant patient as it does on an experienced and skilled surgeon.

EN: How soon should surgery be performed after the injury?

CB: For many years it was common to operate on the injured knee as soon as possible following the injury. Over the last decade many studies have shown that better results are achieved when surgery is postponed until the swelling and inflammation in the joint subside, and a normal range of motion, as well as adequate thigh muscle strength are restored. The waiting period varies from patient to patient; in general it’s about 4 – 6 weeks. Initial treatment of the knee following an ACL tear consists of ice to control pain and swelling, and a knee brace and crutches to protect the knee from further injury. Once the correct diagnosis has been established, physical therapy can help to prepare the patient for surgery.

EN: Please explain the significance of the tissue bank at Zayed Military Hospital. How does the tissue bank help patients with knee injuries?

CB: As you can imagine, knee injuries are a major problem for the military population. Before we developed the tissue bank, many patients with failed ACL surgery were faced with two unsavory options: either they had to travel abroad for surgery, or their surgeon had to harvest tissue from their good knee! Today at Zayed Military Hospital, we see many patients whose original surgery failed – usually because of incorrect placement of the ACL graft. For these patients, having allograft tissue available allows us to avoid harvesting yet another graft from a knee that is already weakened. We also see many patients who have sustained injury to multiple knee ligaments, usually a result of road traffic accidents. Tissue from the bank allows us to reconstruct all of the injured ligaments without harvesting tissue from a knee which has already been severely damaged.

EN: What are your recommendations for rehabilitation following knee surgery?

CB: Appropriate rehab is crucial! Our goal is to restore the athlete to their previous activity level without compromising the new ligament’s healing. Because it takes several months for a new graft to mature, improper rehab can interfere with this process. Improper rehab can also damage the delicate layer of articular cartilage, a cushioning material which covers the ends of the tibia and femur. Injury or damage to articular cartilage can lead to progressive pain, swelling and loss of function. For all of these reasons, the physical therapist must be very selective when prescribing post–operative exercises for ACL patients.

EN: After rehab, can an athlete who has undergone ACL reconstruction expect to return to full competition with the same level of playing as before?

CB: Not right away. Many of the movements that athletes make are done reflexively. In other words, the athlete reacts before he is fully aware of a situation. For example, a football goalie cannot wait to move until he sees which direction and how fast the ball is approaching. The muscles around the knee joint also react reflexively, not only to move toward the ball, but also to prevent injury. Many times when the knee could be dangerously twisted out of position, the muscles around it fire quickly to bring it back into alignment. The nerves that trigger this response are called proprioceptors. The ACL contains many proprioceptors which are lost when the ligament is damaged. Unfortunately, these nerve fibers are not restored by ACL surgery. Therefore the athlete must work hard at balance and co-ordination drills in order to retrain his reflexive system.

EN: What about prevention? Can anything be done, particularly among football players, to prevent or reduce the incidence of ACL injuries from happening in the first place?

CB: Artificial playing surfaces have been implicated as a cause of knee injuries. If you have a choice, play on natural grass. Proprioceptive training, also known as “Sportsmetrics,” may also provide some benefits. A recent study performed on Italian football players concluded that proprioceptive training – jumping, landing, balance drills – reduced the incidence of ACL injuries.