Overuse injuries are seen in primary care practice more often than are acute athletic injuries. These patients present with musculoskeletal pain over a period of time and without any acute antecedent trauma, although there is usually a history of increased physical activity prior to the onset of symptoms. The pain can be reproduced or enhanced by some particular movement. These injuries are due to repetitive microtrauma to some portion of the musculoskeletal system, and in young adolescents, the apophysis is the usual site. They are self-limited conditions that can be managed in almost all cases by primary care physicians. This article discusses the most common apophysitis syndromes in children and adolescents (Table).
Growth of bones occurs principally at three sites - the epiphyseal plate, the articular cartilage, and the apophysis. The latter is a cartilaginous area with its own growth plate separate from the epiphyseal plate and is the site of a major tendon insertion. When overuse results in microtrauma and inflammation at the apophysis, it is called apophysitis. Overuse injuries also occur in other tissues such as tendons (tendinitis) and bones (stress fractures).
Some factors considered to contribute to these injuries in the older child and young adolescent are:
* decreased flexibility of muscles and tendons with age, particularly evident during the adolescent growth spurt and
* underuse of the musculoskeletal system in children who are not physically active, but who begin an intensive athletic season with little time to gradually condition their muscles to gain strength and flexibility.
This is not only the most common cause of anterior knee pain in children and adolescents, in one pediatrie sports clinic, it also was the most common complaint of any kind from athletes younger than 16 years of age.1 It generally is considered to be a "traction apophysitis" of the anterior tibial tubercle, although sometimes there is an actual partial avulsion of the tubercle. The apophysis is the attachment site of the patellar tendon, and repetitive forces on the quadriceps (or patellar) tendon from repeated extension of the knee cause microavulsion fractures of the apophyseal area. This microtrauma results in pain and inflammation that will cease with healing following rest or when growth ceases as the apophysis fuses with the epiphysis. It is seen most commonly in the rapidly growing, athletic boy in early puberty. The average age of onset is 13 years in boys and a year earlier in girls, and the condition is bilateral in half of the patients. The sports most associated with it are ice hockey and soccer for males, and gymnastics and figure skating for females. The natural history of the condition is for the discomfort to continue for at least several months if physical activity continues. Patients frequently are left with permanently enlarged tibial tubercles, and most continue to have pain when kneeling for many years after the acute inflammatory period.
Common Apophysitis Syndromes In Children and Adolescents
Localized pain with knee extension or extreme flexion for at least a month is the usual initial complaint to the physician. The physical findings are confined to a swollen tender anterior tibial tubercle. The pain can be reproduced by either extending the knee against resistance or having the patient squat with the knee in full flexion and "duck-walking." Although the diagnosis is a clinical one, an argument can be made to obtain a radiograph in unilateral cases to exclude a more serious diagnosis such as a bone tumor. Roentgenograms show only some soft-tissue swelling along with the normally irregularly ossified apophysis.
As this is a self-limited disease, conservative treatment is usually all that is necessary. A careful explanation should be given to the patient and at least one parent that symptoms usually persist for 3 months or longer, even with activity restriction, but they can persist for a year or more. The therapeutic plan will be to modify or temporarily stop those physical activities that worsen the discomfort. The patients need to be instructed that "rest" means resting the involved legs only, not the rest of the body, and they should be encouraged to continue to exercise the uninvolved portions of the muscular system. In many patients, however, symptoms are mild enough that the athletes elect to continue to play for that particular athletic season, promising to follow the advice to rest the knee as much as possible "as soon as the season is over." In that situation, the student should perform hamstring and quadriceps stretching exercises for 5 minutes before athletic participation, and the pain can be relieved by ice application to the anterior tibial tubercle for 10 to 15 minutes after sports participation. Ibuprofen is usually an adequate analgesic, but its use means the patient is not restricting activity sufficiently. Corticosteroid injections can give some relief but are rarely indicated because of the risks of subcutaneous tissue atrophy and degenerative changes to the patellar tendon. A "doughnut" felt pad can be cut out and taped over the tender tubercle for protection if activities (such as hockey or football) result in painful blows to that area. Only rarely does the pain persist into adulthood, and in those cases, a toentgenogram generally will show a separate bony ossicle at the insertion site. This complication can be treated by surgical excision.
Before the resumption of normal physical activities, these patients should be instructed in hamstring stretching exercises (to increase flexibility and decrease patellar tendon tension during extension) and quadriceps strengthening exercises (as those muscles may have been weakened by painful inhibition).
SEVER'S DISEASE (CALCANEAL APOPHYSITIS)
Chronic heel pain is a common complaint of the athletic young adolescent. The powerful gastrocnemius-soleus muscle inserts into the posterior calcaneus as the Achilles tendon. Repetitive overuse causes microtrauma to the apophysis at the site of insertion, and this results in symptomatic inflammation. Excessive foot pronation can be demonstrated in many of these patients. This form of apophysitis is seen most commonly in 9- to 12-year-old athletes, whereas Achilles tendinitis, another overuse injury that causes pain and tenderness in the tendon superior to its insertion into the calcaneus, usually is seen only in the adult athlete.
The complaint is heel pain made worse with running and is bilateral in about half of the cases. Physical examination reveals only tenderness with medial and lateral compression of the calcaneus adjacent to or at the site of the Achilles insertion. Roentgenograms are of little value as they may show fragmentation and irregular density of the apophysis, but these can be seen on a roentgenogram of the other symptom-tree heel and are considered normal stages in apophyseal development.
Treatment is conservative as this is a self-limited condition. Activity modification, ice for 10 to 15 minutes if the patient has significant discomfort, and a 14-inch heel lift to relieve the stress on the apophysis are generally all that is necessary. The heel lift should be put into all shoes the patient wears, not just the athletic ones. A sorbothane lift, with its slower return to normal size after compression, has a theoretical advantage over simple foam rubber. Stretching exercises of the plantarflexors and strengthening exercises of the dorsiflexors will relieve some of the stress on the apophysis. If there is a recurrence of the condition, wearing heel lifts for an extended period of time after full symptomatic recovery may help prevent another recurrence.
APOPHYSlTlS OF THE HIP
Less common than either of the ahove is inflammation at the apophyseal sites around the pelvis where abdominal and hip muscles originate and insert. Usually, it is the iliac crest that is involved, but apophysitis also can occur at the antero-superior and ancero-inferior iliac spines, and at the ischial tuberosity. It usually is seen in the athletic boy during his adolescent growth spurt, particularly if he is involved in intensive training or sports competition. Running, football, lacrosse, and ice hockey seem to be the sports most associated with it.
The discomfort begins insidiously, and eventually there is pain with activity, and the pain diminishes with rest. Physical examination reveals only tenderness over the involved apophysis, and the pain can be enhanced by resisted abduction of the hip. The hip can be shown to have a full range of motion. Unless the pain and the tenderness are localized clearly only to the iliac crest, a roentgenogram should be obtained as both Legg-Calve-Perthes disease and slipped capital femoral epiphysis could present with hip pain and a full range of motion. In the case of apophysitis, the roentgenogram will be either normal or show a widened apophysis.
Treatment involves at least 3 weeks of rest, ibuprofen for pain, ice application for 15 minutes three or four times a day until most of the discomfort is gone, and then a gradual program of strengthening and stretching the abdominal and hip muscles coincident with a slow return to activity.
This overuse injury is seen in the 10- to 13-year old athletic child and presents much like OsgoodSchlatter disease except that the pain and tenderness are located at the inferior pole of the patella. The pain is worsened by running or stair-climbing. Sports such as soccer and running seem to be those most frequently associated with this syndrome. It is believed by many to be a true apophysitis, although a plain lateral roentgenogram may show an ossicle adjacent to die inferior pole of the patella suggesting the etiology might have been a forgotten macrotrauma.
Treatment is similar to that for Osgood-Schlatter disease, and the patient and parent should be advised that the condition will improve with rest and will be gone when skeletal maturity is achieved.
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Common Apophysitis Syndromes In Children and Adolescents