Overuse injuries are common in an athlete's training. But, adolescents present a new set of problems

Today, not only are more children than ever participating in sports, but a growing number are training and competing year-round. Between school and club programs and summer sports camps, more athletes are also specializing in one sport at ever-younger ages. Add to this the fact that these kids—for boys, in many cases, up to the age of 17 or 18—are still developing musculoskeletally and it’s no wonder that the incidence of overuse injuries among this population continues to climb.

Among overuse injuries, apophyseal injuries, such as Osgood-Schlatter’s Disease, Sever’s Disease, and Sindig-Larsen-Johansson Syn-drome, are unique to the adolescent athlete. These injuries occur at secondary centers of growth, termed apophyses, and are characterized by inflammation at the insertion site of a major tendon into the immature bony prominence. Primary centers of growth—the growth plates—can also be injured through overuse.

Most of these injuries can be successfully treated with a short course of rest and rehab. But unless underlying factors—most importantly, the training—are addressed, these children will end up right back in the athletic trainer’s or doctor’s office. Worse still, because for many children these injuries occur at a time when they are first getting involved in sports, if they go undiagnosed, or are misdiagnosed, the persistent pain can be psychologically, if not physically, career-ending. With proper treatment, however, a return to full participation can be expected in most cases.

What are the common adolescent injuries and disorders associated with these growth spurts and what are the most important considerations in returning these kids to their sports? T&C spoke with John DiFiori, MD, Assistant Professor in the Department of Family Medicine, Division of Sports Medicine, and Assistant Team Physician in the Department of Intercollegiate Athletics at UCLA, about the signs, symptoms, and causes of these debilitating injuries, and how best to treat them.

Fiori: There are three areas in the immature skeleton where you may see overuse injuries: the apophyses; the articular surface of the bone; and the growth-plate, or physis, itself. Some of the most common conditions are apohyseal disorders: Osgood-Schlatter’s Disease, which occurs at the tibial tuberosity; Sever’s Disease, which affects the posterior calcaneous; and Sindig-Larsen-Johansson Syndrome, at the inferior patella. These are traction-site problems, in which a tendon is pulling on an immature bony site.

Children and adolescents may also develop problems that affect the articular surface of various bones. Some of these are a result of a group of disorders known as osteochondroses. The osteochondroses are abnormalities of the joint surface that may occur at several sites, including the elbow, wrist, hip, knee and foot. Although they may be seen in athletically active children, the etiology of osteochondroses is not well known. Thus, the cause-and-effect relationship with overuse is not fully understood.

Osteochondritis dissecans (OCD), which is a focal lesion of the articular surface, is distinct from the osteochondroses. In these injuries, a fragment of the articular cartilage at a joint surface is involved. The fragment may remain in place (in situ), become partially detached, or become completely detached. OCD may be related to a traumatic injury, but in some cases appears to arise from overuse. Joint pain, swelling, locking, and restricted range of motion are common symptoms. The knee and the elbow are common sites for this injury.

OCD can potentially be a significant problem that, in some cases, can result in the development of osteoarthritis. These injuries may be difficult to diagnose. Radiographs may be helpful in identifying the injury. Computed tomography scans and magnetic resonance imaging are also used to help make the diagnosis and to visualize the severity of the injury. It’s important that the possibility of an osteochondroses or OCD be considered in children who present with joint pain.

Accessory ossicles, such as in the foot, where the tendon of the tibialis posterior inserts into the navicular, may also be sites of overuse injuries. This is due to a traction phenomena where the tendon is tugging on a small bone, and it can be quite painful. It’s probably the most similar injury compared to the others that occur at the knee.

As far as injuries to the growth plates themselves, one area that we have a special interest in is how repetitive loading in the skeletally immature child or adolescent affects the primary growth centers. We particularly study young gymnasts. They spend a lot of time putting weight on their upper extremities, and so they develop overuse injuries of the wrist quite commonly. Although there are several sites within the wrist that may be affected, one of the most common appears to be the growth plate itself. The interesting issue is whether or not this affects the growth of the bones of the wrist. We don’t have any direct evidence for that, although we do know that older gymnasts do tend to have a longer ulna, which is the forearm bone on the little-finger side of the wrist, than the general population.

The concern has been that this reflects an interference with growth to the radius (the forearm bone on the thumb side of the wrist), but that cause-and-effect relationship has not been demonstrated. There have also been reports of injuries to the growth plates of the proximal humerus, distal femur, and proximal tibia from overuse. One recent case described premature closure of a growth plate in the thumb of a young musician. These stress injuries are similar to what we study in the wrists of gymnasts.

Many of these injuries occur during the adolescent growth spurt. The timing of that is different between boys and girls. Girls hit their peak height velocity at about 12 and a half or 13; for boys, it’s close to 14 years of age. So, the ages between 10 and 14 are commonly associated with these injuries.

That said, there is certainly a lot of variability in the growth rate from one adolescent to the next. You could use those ages as sort of a broad starting point, but there’s a lot of variability around that. Even some college freshmen may not yet be fully skeletally mature, so it’s important to realize the wide variability in maturation—and that these injuries can occur even in kids several years older than 14.

Are there any tell-tale signs of when a child is most vulnerable to these types of injuries or to developing these disorders?

We’re looking at that and trying to develop some concepts, backed by data, that we can provide to coaches to suggest the things to look for to prevent a particular type of injury for a given sport. The most common question is how much is too much? Most of the time we don’t know what the answer is until after an injury occurs.

We just don’t have the evidence at this point to say to a cross country coach, for example, ‘When a child begins his or her peak height velocity, you need to reduce the mileage by X amount to prevent these things from developing,’ or something like that. And, not all kids are going to develop them anyway. I’ve got coaches asking me for that kind of information all the time, but, unfortunately, we don’t have that right now. Hopefully, we’ll be able to develop that. But for now, making sure equipment is properly sized, incorporating scheduled rest periods in the training schedule, and modifying the training during the growth spurt, appear to be reasonable preventative measures.

Traditionally, some of the contributing factors have been thought to be things like quadriceps weakness, quadriceps inflexibility, hamstring inflexibility, and any patello-femoral biomechanical malalignment or other lower-extremity malalignment. We particularly assess these issues for the entire lower extremity and the spine because of their importance in absorbing the forces that are generated with athletic activities.

These intrinsic factors—biomechanical alignment and strength and flexibility—need to be addressed with the thought that they may contribute to the development of some of these adolescent overuse injuries, such as Osgood-Schlatter’s Disease. But, it’s important to note that if they’re not addressed, even though the Osgood-Schlatter’s may resolve, these factors may, in the future, contribute to other lower-extremity overuse injuries.

Even though we look at all of these intrinsic factors, it’s important to emphasize that a lot of children and young adults—and even older athletes—will have some biomechanical abnormalities. Furthermore, there has yet to be any cause-and-effect relationship demonstrated between those biomechanical factors and the development of overuse injuries. At this point, there isn’t any hard evidence to say that in fact there is a causal relationship.

So, what we do is we assess those factors and we put that information together with another very important factor, which is the training program. Even in young children, if they or their coaches or their parents have innate errors in their training program, that is probably the most important contributing factor and what really needs to be addressed.

What, then, are some of the signs and symptoms that you look for in a clinical evaluation?

There are a variety of diagnostic tests and imaging studies that can be used to establish the diagnosis. But, what you want to do is get at the cause of the problem, not just the extent of the injury. For that, the most important thing is to get a thorough history from the youngster.

Analyze the training program in the weeks preceding the injury. Because these injuries are generally caused by problems in training, the questions should focus on uncovering any changes in training intensity, frequency, or duration. And, were there any other abrupt changes in such things as the equipment or the surface or environment?

Next, find out when the pain is worse—whether it’s during activity, just after activity, the next day—and specifically what actions make it worse. Try to recreate the movements that cause the most pain, and palpate the area to localize the exact location of the injury. It’s not unusual, however, for overuse injuries to be difficult to localize, such as with radiating back pain.

If the parents are present, observe the interaction between the child and his or her parents. Do you get the sense that the child is participating in the sport out of his or her own interest or at the insistence of the parent? There’s a lot you can learn from watching them interact, and by noting who does most of the talking when you ask questions. Are the parents’ expectations realistic? Is the child motivated to participate out of his or her own interest? Or, are there outside pressures—this could be the parents or the child’s peers—that are contributing to the child’s participation?

Once you have made a diagnosis of one of these growth-related disorders, what are some of the treatment considerations?

Rest and icing the injury are recommended to interrupt the overuse process. Then, a program of rehabilitation is implemented. The objectives of rehabilitation are to restore range of motion, strength, flexibility, and proprioception. Return to activity should be preceded by a gradual resumption of sport-specific skills. Pushing through that phase too quickly can lead to re-injury.

As we talked about, there may be anatomic or biomechanical contributing factors, which need to be addressed. If the child is going to return to sports, anything improper in the training has to be corrected. Inappropriate equipment, including footwear, should be replaced. It’s important to include the child’s parents and coach in the discussions, to make sure they understand what’s needed to prevent another injury.

In getting them back to their sports, we really focus in on any training errors that resulted in the injury in the first place, such as changes in frequency, duration, intensity of training, whether there have been proper rest periods as part of the training program, whether there’s been an appropriate progression of training with those periods of rest. The training always needs to be individualized in the sense that one child may be progressing at a much faster rate of maturity than another.

In a young child especially, we also look at equipment—is the equipment properly fitted, is it in good shape, is it well-maintained—as well as if there have been proper safety measures and supervisory measures in place. All of those sorts of things need to be evaluated. If they’re not addressed at the time of something like Osgood-Schlatter’s, later on, if the same patterns persist, it could be a set-up for future overuse injuries.

If treated properly, what’s the future look like for a child or teenager with a growth-related disorder?

In general, if they’re appropriately treated, most do quite well. Typically, the apophyseal injuries respond well to rest and rehabilitation. They can return to sports and enjoy a full level of participation. Those with osteochondroses must be carefully monitored by a physician. Although the course of the disorder is dependent upon several factors, the majority are self-limited.

Youngsters who are diagnosed with osteochondritis dissecans require a thorough diagnostic workup and treatment plan. If the fragments are significantly displaced, or become dislodged and are loose in the joint, surgical intervention may be necessary. Return to sports in these cases must be individualized and in consultation with a physician.

In addition, we do not have any data on the long-term impact of overuse injuries that affect the growth plate. In that sense, too, each case must be individualized. But, especially for apophyseal injuries, kids should be reassured that with proper treatmentt and time, they can get back to their activities at full-participation level.

The following articles are a sampling of literature providing information on adolescent growth-related disorders:

DiFiori JP. Overuse injuries in children and adolescents. The Physician and Sportsmedicine 27:75, 1999.

Andish JT. Osteochondritis dissecans in a young pitcher. Why early recognition matters. The Physician and Sportsmedicine 24(3):85, 1997.

DiFiori JP, Mandelbaum BR. Wrist pain in a young gymnast: unusual radiographic findings and MRI evidence of growth plate injury. Med Sci Sports Exerc 28(12): 1453, 1996.

Maffulli N, Baxter-Jones AD. Common skeletal injuries in young athletes. Sports Med 19:137, 1995.

Peck DM. Apophyseal injuries in the young athlete. Am Fam Phys 51:1891, 1995.

Smith AD, Tao SS. Knee injuries in young athletes. Clin Sports Med 14:629, 1995.

By Guillermo Metz, with John P. DiFiori, MD

Guillermo Metz is the Managing Editor of Training & Conditioning magazine. John P. DiFiori, MD, is Assistant Professor in the Department of Family Medicine, Division of Sports Medicine, and Assistant Team Physician in the Department of Intercollegiate Athletics at UCLA.

Training & Conditioning, 10.4, May/June 2000, http://www.momentummedia.com/articles/tc/tc1004/toofar.htm