MARC J. PHILIPPON, MD
WILLIAM R. MOOK, MD
KAREN K. BRIGGS, MPH
Editor’s Note: It seems fair to say that co-editor Marc Philippon has long been regarded as the most important innovator in hip arthroscopy. Marc sits high on top of this specialty’s mountain and sees many things before others. As a result, he has operated on many high-level athletes and other famous people. I asked Marc to write about the intricacies of hip arthroscopy. Marc’s research director and fellow join him as co-authors.
There is no such thing as a routine diagnosis.
—Marc J. Philippon, MD.
Please forgive all the ice hockey parallels in this section. I can’t help it. I love the sport, and I love taking care of many of the sport’s players. Their lingo has become part of my nature.
In that vein, the main goal in this chapter is to avoid bumps, fights, and distractions and to score more goals than our opponents. Our opponents in the hip joint are all the factors that contribute to the symptoms of femoroacetabular impingement (FAI). We need to do whatever it takes to score goals against that bad anatomy.
Making an accurate diagnosis of FAI may sometimes seem easy, and treating it through the scope is as straightforward as lighting the lamp (Figure 27-1). That phrase refers to a red light flashing, whenever the siren sounds, to indicate that someone has scored a goal. In the eyes of young professional ice hockey players, all goals are “easy.”
The same thing basically holds for new hip arthroscopists. Once one has developed the tools and training to arthroscope hips, correcting hip impingement usually seems easy. Both the young professional hockey players and young arthroscopists are wrong. Rarely are things as straightforward as they seem.
Just as Tom Byrd pointed out in an earlier chapter, the improved understanding of the pathophysiology, anatomy, and natural history of FAI is all a recent phenomenon. Our new understanding has led already to improved outcomes and novel arthroscopic techniques. Yet, we remain still very much within a learning phase with respect to our knowledge base. Therefore, unavoidable surgical pitfalls still leave many patients in need for revision surgery.
The second ice hockey idiom—getting your face washed (Figure 27-2)—refers both to ice hockey and hip arthroscopy. In hockey, the expression means being taken into the boards by an opponent and having that player’s sweaty, smelly hockey glove rubbed all over your face. The same holds for hip arthroscopy, only the opponent is the player’s seemingly straightforward bad hip anatomy.
This chapter will do 3 things:
- Expand on Dr. Reinhold Ganz’s initial description of FAI
- Review the diagnosis and treatment of FAI as we understand it today
- Connect some of this current understanding to other parts of the core and its potential muscular imbalances
We will try to keep this chapter as simple and straightforward as possible. We shall share some illustrative clinical examples from the world of sports. We shall also provide what we think is a pretty reasonable treatment algorithm for the evaluation and treatment of patients with continued pain and/or dysfunction following hip arthroscopy. Finally, we shall hone in on what may be an important target for FAI prevention.
A good hockey player plays where the puck is.
A great hockey player plays where the puck is going to be.
—Wayne Gretzky. Nicknamed “The Great One,” Gretzky had more goals and assists than any other player in NHL history.
HIP INJURY DURING SPRING TRAINING
In parallel with Dr. Meyers’s experience with core muscle injuries and his prior description of a prominent quarterback, we have been dealing with many elite professional athletes suffering from un- or misdiagnosed injuries in the region of the hip. Let us tell you about one baseball star who came to us in the middle of spring training (Figure 27-3).
This elite slugger was referred for evaluation of his groin pain that prevented him from turning effectively on pitches. He could not hit the ball with full strength and described “hip weakness and tightness.” The pain was hurting his performance. Such vague but real complaints are all too common in today’s competitive athlete. In years past, without high-resolution diagnostic imaging and the option of predictable success with minimally invasive treatment, the radiographic findings of FAI and a labral tear usually went unnoticed and untreated.
Fortunately, this elite athlete’s all-star team of coaches, trainers, and doctors recognized the reason for his declining performance. The team had the foresight to recognize “where the puck was going to be,” prior to irreversible damage to his joint, and referred him for treatment.
Often, it takes 5 to 6 months to recover from such surgery. This future Hall-of-Famer lit the lamp. With the bony impingement and labral tear addressed, he made a full recovery and returned the same season and helped lead his team to a World Series championship (Figure 27-4).1–3
The most common sports hip problem is FAI, which comes, literally, in all shapes and forms. We see athletes, and nonathletes, from all over the world, and I remain amazed at how much we continue to learn and how much we still need to learn. FAI remains in its infancy with respect to our understanding of its pathophysiology and natural history. We know much more about short- and medium-term consequences.
SEEING WHERE THE PUCK WAS GOING
Wayne Gretzky’s famous quotation describes my friend and colleague, Reinhold Ganz, the world’s top expert in hip preservation. Reinhold, still Professor Emeritus at the University of Bern, had eyes that no one else had. Dr. Ganz watched from behind the net, just like Gretzky, and recognized “where the puck was going to be.” He saw the various femoral and acetabular shapes most likely associated with soft tissue labral tears and subsequent arthritis.4,5 Dr. Ganz went even further and described FAI as a distinct clinical syndrome that was determined by the bony architecture of the hip.
He asserted, basically, that action at a certain anatomic site placed individuals at great risk for arthritis: the abutment of the acetabular rim (ie, hip socket) against the femoral head-neck junction.4–6 He described several distinct subtypes of FAI. He referred to abnormalities of the acetabulum as pincer deformities, and those of the femoral head or neck as cam deformities. Then, of course, there were deformities at both the acetabulum and femur, which he called the mixed-type FAI (Figure 27-5).
With the cam deformity, there is a bony prominence or “bump” of the proximal femoral head-neck junction. The bump prematurely engages the acetabulum during hip flexion. This contact is what leads to shearing there between the articular cartilage of the femur and the fibrocartilaginous labrum. Damage occurs to either the articular cartilage or the labrum or both. Both cam-type and pincer-type impingements may cause groin pain and disability in young adults, and particularly those who participate in athletic activities. Unquestionably, the deformities combined with the bony contact may predispose patients to osteoarthritis.7,8
In addition to my personal experience, several authors have also noted that a large percentage of patients with cam, pincer, and mixed-type FAI bony abnormalities also tend to develop changes of global joint degeneration at a relatively young age.9–11 Dr. Ganz’s appreciation of these bony abnormalities as a definite source of articular cartilage and labral damage, and possible cause of hip osteoarthritis, have paved the way for the development of the diagnostic and treatment technologies that have led to our current understanding of FAI.
I am going to be ambitious with this chapter and try to accomplish 6 things:
- Expand on Dr. Ganz’s initial description of FAI
- Correlate the pathology of FAI to other parts of the core, particularly the core muscles and back
- Kibitz on our current concepts about the diagnosis and management of FAI
- Share several cases that illustrate particular diagnostic and/or treatment challenges
- Propose an algorithm for evaluation and treatment of patients with continued or new dysfunction following hip arthroscopy
- Theorize about where we want “the puck to be” (ie, I will present a hypothesis aimed at preventing FAI, ideally the ultimate goal for all well-meaning arthroscopic scientists)
Wow, I am exhausted already. That was the longest sentence I’ve ever written!
THE WAY IT WAS
The concept of FAI dates back to 1936,12 not long after Burman first introduced arthroscopic surgery in the hip.13 Abnormal bony features of the hip were not associated with cartilage injury and the early onset of osteoarthritis until the 1960s and 1970s. Murray and Stulberg were the first to describe an abnormal relationship between the femoral head-neck junction in patients with unexplained early arthritis of the hip.14,15 They coined the terms head tilt and pistol grip deformities of the proximal femur. Although forward thinking, they did not offer an explanation as to how the abnormal radiographic bony features of the hip led to cartilage injury and later joint degeneration.
It wasn’t until the 1990s when Dr. Ganz and his colleagues theorized that decreased clearance of the femoral head-neck at the bony socket led to pathologic contact of the 2 surfaces. Repetitive abutment of the neck against the acetabular rim, in turn, led to labral and articular cartilage shearing, ending up in joint degeneration. Ganz’s group also was the first to act preemptively on the proposed abnormal anatomic relationship. They attempted to correct it surgically.
Consider the hip joint a highly congruent ball-and-socket joint buried deep within an environment of muscular, ligamentous, capsular, and neurovascular structures where complex dynamic interactions allow for amazing athletic feats. Historically, this complex anatomy struck fear with respect to accessing the hip joint surgically. Traditional open surgical approaches appeared invasive and associated with potential complications. Additionally, the proximal femur has a complex vascular anatomy that might be disrupted. So, even though surgeons, like Murray and Stulberg, were able to see the bony impingement abnormalities associated with cartilage injuries, surgical correction of the abnormalities was another matter. Safe surgical repair seemed a pipe dream. Native hip anatomy posed a substantial obstacle.
Then Ganz and his colleagues fastidiously characterized the vessels that maintained the integrity of the femoral head and neck.16 For example, the lateral epiphyseal vessels of the medial femoral circumflex artery were important. In the setting of a traumatic hip dislocation or fracture, damage to those vessels would starve the articular surface of the nutrients it needs, and the hip would undergo the dreaded degenerative process called avascular necrosis.
An open surgical technique then emerged, based on the vascular anatomy described by Ganz. The technique involved exposure of the hip joint by dislocating the ball and socket. This allowed anterior exposure of the hip joint by cutting through bone (ie, osteotomy), so as to preserve the medial femoral circumflex artery, the main blood supply of the femoral head.17 The technique permitted a 360-degree view of the femoral head and neck and acetabular socket. With this exposure, surgeons could eliminate the bony or other abnormalities causing impingement and also create freer motion. With his excellent results, Ganz convinced others that the pain and other symptoms of hip impingement could be relieved. Possibly, they could even prevent further joint space narrowing, particularly if the problem was recognized early and addressed prior to the development of severe hip joint osteoarthritis.18
The development of minimally invasive arthroscopic techniques in the hip lagged behind the developments in other joints due to these obvious anatomic limitations. Although the first report of a clinical application for hip arthroscopy was presented in 1939 by Takagi,19 it wasn’t until the late 1970s and 1980s that the technique re-emerged as a viable option for the treatment of intra-articular disorders. Dr. James Glick, in San Francisco, should be credited with popularizing hip arthroscopy and providing the foundation in the late 1980s. He paved the way for modern hip arthroscopists and the techniques developed in North America.20,21 Thomas Byrd then essentially redefined how hip surgeons should approach the hip arthroscopically and popularized the supine approach, which is the one most utilized.22 Technological advancements and techniques of hip arthroscopy have swiftly accelerated since the early 1990s.
The minimally invasive nature of hip arthroscopy delivers valuable advantages, such as minimal morbidity, fast recovery, and quicker return to sport or other normal activities. It affords the same 360-degree access to the femoral head, neck, and acetabular socket as surgical hip dislocation. Modern hip arthroscopy greatly expanded the practical applications of a whole new therapy envisioned by Dr. Ganz, who had the new eyes and set the foundation. Modern surgeons now help numerous young people, and some older ones, who have the condition we call FAI. Recovery from surgery is probably faster than Ganz initially conceived, and elite athletes can return to their pre-injury levels of play after numerous nonoperative measures have been tried.
THE WAY IT IS
The ball-in-socket hip joint does not exist in isolation. It is part of the core—the whole region of the body from the mid-chest to the mid-thighs. The core, as we define it, includes everything in this region of the body. For convenience, we divide it into the 4 parts outlined in an earlier chapter: the back, the core muscles and rest of the pelvic bones, the hip, and then everything else—all the organ systems, nerves, blood vessels, etc.
The advances in our arthroscopic technology and techniques for treating disorders of the hip joint over the past decade are remarkable, and it is amazing how much we can do now within that narrow space called the hip. But we should also recognize that our understanding of the relationship between the dynamic and static stabilizers of the core, hip, and lower extremity is expanding and that this is critical to the evaluation and treatment of the athlete with pain about the pelvis and the pelvis’s many articulations. The primary point is to remember that as we focus more on the pathology in the ball-in-socket hip joint, hip injuries rarely occur only there, in isolation. To understand fully why many hip injuries occur, the relationship between the hip and rest of the core must be more fully appreciated.
For starters, think about this. Each bony hemipelvis, or innominate bone, provides the physical connection between the spine and both lower extremities, via the sacroiliac joints and the pubic symphysis, respectively. Each innominate bone of the pelvis also contains the acetabulum (ie, hip socket), which provides the proximal bony articulation for each hip joint (Figure 27-6). The position of the pelvis relative to the lower extremities is a result of the interplay between its inherent bony architecture and the forces that act on it in the form of muscular attachments.
The position of the pelvis relative to the lower extremity is often objectively quantified radiographically by a measurement referred to as pelvic tilt. Pelvic tilt is my (MJP) pet venture into understanding how the hip interacts with the rest of the core. As I see it, in his chapter, Thomas Byrd identified 4 likely important, contributing extra-articular anatomic factors involved in FAI: the core muscles, lumbar lordosis/kyphosis, femoral version, and pelvic orientation. Based on my biases, I have chosen a specific type of pelvic orientation, pelvic tilt, on which to focus a fair amount of my attention.