CHAPTER 29 The Immature Spine and Athletic Injuries

Most spine injuries in athletically active children and adolescents are chronic, resulting from repetitive demand on the immature spine during participation in sports. The most serious injuries are acute as a result of direct trauma. The age at which a child can be considered an athlete varies and may be 3 years old when a child puts on skis or 10 years old when he or she begins to ride bulls (Fig. 29–1). Several sports, such as skiing, football, and horseback riding, involve increased risk of acute traumatic events, making spine fracture a significant concern when considering an adolescent athlete. This chapter discusses the initial evaluation and on-field management of spine fractures; the complete treatment of spine fractures is covered elsewhere.

FIGURE 29–1 This 10-year-old boy is following the traditions of ranch life in Colorado where rodeo is a part of life. He won his first big belt buckle in competition at 8 years old.

According to surveys of patients seen in sports medicine specialty clinics, the most common cause of back pain in adolescent athletes is stress fracture, or spondylolysis. Spine hyperextension and repeated twisting contribute to the high rate of spondylolysis seen in sports such as gymnastics, football, and weightlifting. The rate of spondylolysis in gymnasts is 20% compared with 5% to 6% in the general population.¹

Less aggressive sports such as golf can also cause adolescent back pain and spine injury. The golf swing places significant torque on the spine and surrounding muscles and can produce strains and sprains, which are minor injuries that interfere with performance. In all sports, appropriate strength training, routine stretching, and good technique are imperative for young athletes to avoid injury and to continue participation in sports throughout their lifetime.

The most effective technique in screening for serious disease is a good patient history, and diagnosing spine injury is no exception. Although helpful, a radiograph is seldom definitive in diagnosing the cause of back pain. Radiography is imperative for diagnosis of an acute fracture, but back pain without a specific injury is usually treated on the basis of a careful history and a thorough physical examination.

Understanding the requirements of the particular sport and gaining knowledge of the training schedule of the athlete are important when performing the patient history. For example, a gymnast with no history of sudden trauma who practices 3 hours daily has a chronic stress that may account for her back pain. A young gymnast’s developing spine, given insufficient recovery time, is highly susceptible to repetitive trauma.

Return to sport is a major goal for an athlete, and the physician needs to be aware of the demands of the specific sport to determine when return to participation is reasonable. The physician should take heed of a young athlete who is reluctant to return to sport after an injury. Family dynamics often influence when a child is willing to resume activity.

Physical activity is the normal function of the musculoskeletal system. The American Academy of Orthopaedic Surgeons (AAOS) has encouraged physical activity as health promoting for all ages in its “Get Up, Get Out, Get Moving” program. The keys to maintaining a healthy spine are good nutrition and proper exercise. Good nutrition includes avoiding obesity and not smoking. Exercise programs should include strengthening for power and endurance and stretching to improve joint range of motion and muscle length.

Principles of Diagnosis

The initial treatment of low back pain usually begins without a specific diagnosis. A nonspecific diagnosis is satisfactory as long as the patient’s condition improves. In contrast, the narrow area in which surgery offers reliable benefit to the patient requires a carefully determined, specific diagnosis.

History

A good patient history depends on effective patient-physician communication. When a patient presents with low back pain, the history is important to rule out serious diagnoses rather than leading to a definitive diagnosis. The physician brings knowledge of possible causes and treatments to the interview and assembles a differential diagnosis. The patient wants to tell his or her story and brings knowledge of timelines and anecdotal details.

The term interview implies an interaction with the patient as opposed to the traditional notion of extracting information from the patient. When allowed to tell his or her story, an adult patient takes an average of 90 seconds.² Adolescents tend to be more taciturn and talk less than the average adult. The average physician cuts off the patient with a question after 18 seconds because he or she has formed a differential diagnosis. Such interruption stops the flow of information, and often the patient is never permitted to relate pertinent facts.

The use of a visual pain scale facilitates consistent documentation. The patient’s assessment of the intensity of the pain using a visual scale (Fig. 29–2) often stimulates a description of the circumstances that exacerbate or alleviate that pain. When making the differential diagnosis, the physician can classify the clinical syndrome into one of three categories: (1) nonmechanical back or leg pain (or both), (2) mechanical back or leg pain (or both), and (3) sciatica.

FIGURE 29–2 Bieri faces. Drawings are neutral in terms of gender and ethnicity. The patient indicates a number that corresponds to his or her pain between 0 and 10.

Warning signs for possible cancer include a history of cancer or constitutional symptoms such as fever or weight loss. Risk factors for infection include a history of recent bacterial infection, intravenous drug use, or an immunocompromised state. Patients with a spine cancer or spine infection often have pain that is not diminished by rest. Warning signs of possible spine fracture are major trauma (e.g., motor vehicle accident, blunt trauma, fall from a height), prolonged corticosteroid use, and osteoporosis. Symptoms suggestive of cauda equina syndrome, which requires urgent surgical consultation, include saddle anesthesia (found in 75% of patients); recent onset of bladder or bowel dysfunction (with urinary retention the most common symptom); and severe or progressive weakness of the lower extremities,³ especially involving both lower extremities.

There are several findings to note when ascertaining psychosocial contributions to nonorganic back pain, as follows ⁴:

1 Superficial nonanatomic tenderness. Lightly pinching or rolling the skin should not affect the deep structures, which might cause true pain.

2 Patient’s response to positive stimulation such as axial loading. Lightly placing one’s hand on top of the head should not significantly increase pressure in the low back.

3 Distraction. One should look for a significant difference in straight-leg raising ability in the seated versus the supine position.

4 Overreaction. An overly loquacious patient or behavior disproportionate to the stimulus should be noted.

5 Disturbances in sensation or distribution of pain or weakness that do not follow anatomic patterns.

Symptoms and signs that suggest back pain from nonmechanical causes, such as subclinical pyelonephritis, kidney stones, or dissecting aneurysm, should also be considered.

Genetics

The “wild card” in the etiology of sciatic pain is genetics. Ala-Kokko ⁵ noted that scientific studies have identified specific versions of the genes encoding collagen, aggrecan, vitamin D receptor, and matrix metalloproteinase-3 that have significant associations with lumbar disc disease. Many other genes may also play a role in disc disease.⁶^–⁸

Physical Examination

The physical examination should take into consideration the three reasons for orthopaedic consultation: pain, deformity, and dysfunction. Although there is poor correlation between physical findings, symptoms, and treatment outcome, an examination of the patient’s back is necessary. The purpose of physical examination is to confirm the impression gained from the history, if possible, and to look for surprises. Many obvious anatomic abnormalities can be visualized only when the patient’s back is bare. The physical examination usually helps to exclude a serious disease rather than identify one. The “three S’s” of an abnormal spine examination are apparent to observation: spasm, scoliosis, and spondylolisthesis.

Watching the patient move in flexion, extension, and rotation gives a visible assessment of pain. How a patient moves is as important to note as the range of motion. Whether the patient can bend to the knees, below the knees, or to the toes provides a rough measure of flexibility. Observing spinal rotation allows one to evaluate the facet joints.

After checking range of motion and palpating for tenderness and muscle spasm, the physician should observe the rotational symmetry of the spine using the Adams forward-bend test and noting whether the pelvis is level. It is worthwhile to observe the effect of compression of the pelvis while the patient is lying on his or her back because this is a nonspecific test for sacroiliac joint disorders.

Observing standing posture in the coronal and sagittal planes is important to document evidence of deformity. Special tests such as one-leg standing (the stork test) and compression tests for the neck (Spurling test) are indicated when one suspects spondylolysis or compression neuropathy. Anisomelia can be diagnosed by measuring limb lengths from the anterior superior iliac spine to the medial malleolus.

The neurologic examination requires close attention to detail and begins by having the patient heel walk and toe walk. Both functions demand strength, coordination, and cooperation one would expect from an athletic child. Testing deep tendon reflexes is important, especially if they are asymmetrical; testing the abdominal reflexes is essential to detecting hydromyelia.

The straight-leg raise test or Lasègue sign is a test for nerve root irritation or inflammation. A positive response is the reproduction of radicular pain. Pain on the opposite side or a positive “cross straight-leg raise test” is significant for diagnosis of a herniated disc. The straight-leg raise test can simultaneously provide evidence of sciatica and hamstring contracture.

Imaging

Modern imaging techniques such as computed tomography (CT) and magnetic resonance imaging (MRI) permit accurate visualization of anatomic defects in the spine. Although both techniques are powerful diagnostic tools, the defects revealed by CT or MRI are not always causative with regard to the patient’s pain. The literature is replete with cases in which anatomic defects are present on MRI or CT in completely asymptomatic patients.

The Cochrane group performed a meta-analysis of the literature and concluded that there is no correlation between radiographic changes and back pain.⁹ Contrary to that opinion, researchers in Tokyo reported a study in which they correlated preparticipation spinal radiographs with the incidence of back pain and disability among young football players.¹⁰ They followed 171 high school and 742 college football players over a 1-year period. High school players with spondylolysis had a higher incidence of low back pain (79.8%) than players with no radiographic abnormality (37.1%). College players with spondylolysis, disc space narrowing, and spinal instability had a higher incidence of low back pain (80.5%, 59.8%, and 53.5%) than players with normal radiographs (32.1%). College players with spondylolysis had a higher incidence of low back pain than players with disc space narrowing and spinal instability.

How can this incongruence of findings be explained? It is believed that asymptomatic abnormalities in the general population, particularly abnormalities seen with aging, may become symptomatic with vigorous physical activity. Abnormal spine radiographs in a young athlete should be considered a risk factor for injury.

Principles of Treatment and Rehabilitation

Acute Treatment

When pain onset is acute and severe, bed rest may be necessary for 2 or 3 days for initial pain control. A longer period of bed rest quickly becomes counterproductive. The key to recovery is modified activity within a minimal range to start, followed by gentle progression of activity. The sooner the athlete begins a level of tolerated activity, the quicker and more effective is the recovery. Research and experience have dispelled the notion that prolonged absolute rest is beneficial for treatment of back pain.¹²

Nonsteroidal anti-inflammatory drugs can be potent when given with muscle relaxants, but the duration of medication should be no longer than 10 days. Opioid administration is rarely necessary for more than a few days. Local anesthetic injections into the facet joints or into trigger points can be useful treatments and may help to diagnose disease related to the facet joint or fibromyalgia.

Passive physical therapy modalities such as ice, massage, or heat can be helpful in initial treatment, but the athlete needs to begin active rehabilitation and assume responsibility for his or her recovery. Strengthening should begin as soon as possible, and bracing should be minimized.

Bracing

Bracing is effective in some cases, if used intermittently and primarily as a tool for returning to activity. If used as a “crutch,” extended time in a brace produces atrophy and loss of motion. The Cochrane Collaboration reported a meta-analysis on the use of braces for low back pain in 2004.¹³ There was moderate evidence that lumbar supports are no more effective for primary prevention than other types of treatment or no intervention. The authors found no data promoting the effectiveness of lumbar supports for secondary prevention. This opinion is consistent with the generally held concept that passive treatment such as bracing should be limited to acute pain relief and that active rehabilitation is an early goal for return to participation in sports and prevention of future injury. Spinal manipulation can provide short-term improvement, but the evidence for longer term relief is inconclusive.¹⁴

Traction

Traction has historically been used to treat low back pain. Current thought remains disparate, however, regarding the therapeutic value of traction.¹⁵ Multiple reviewers have concluded that traction as a treatment for back pain is an outmoded technology that has fallen out of favor.

Rehabilitation

The rehabilitation program consists of stages—building a foundation of fundamentals and moving through increasingly difficult levels of activity. Physical rehabilitation should be designed to be sport specific and diagnosis specific. A gymnast with spondylolysis needs a program avoiding hyperextension while the bone is allowed to heal. As rehabilitation goals, he or she needs to stay active in the maneuvers that do not stress the back and to maintain general fitness.

Generally, rehabilitation begins with flexion and extension cycles to reduce joint stiffness and relax elastic structures. There should be minimal loading of the spine during this stage. Hip and knee range of motion exercises are added next to offload the spine, followed by specific muscle training. Focus is first placed on the anterior abdominal muscles and maintaining the spine in neutral position, followed by lateral muscle exercises for side support of quadratus lumborum and abdominal wall muscles; finally, an extensor muscle program is added. Repetitions and movement duration should be closely monitored by the therapist.

Core Stabilization

A core stabilization program is based on the principle of coordinated muscle contraction. This contraction is done from a neutral, pain-free position. Finding and maintaining a pain-free position is fundamental to reestablishing isometric muscle control. Flexibility training should not be approached until strength has been regained.

Flexibility

Exercise programs that load the spine throughout the range of motion have poorer outcomes. Greater mobility is associated with poorer outcomes as well. The range of motion of the spine has little predictability for future low back pain. Programs emphasizing trunk stabilization with a neutral spine have had the most success.¹⁶^–¹⁸ These programs emphasize increasing the range of motion of the hips and knees.

Muscle Performance (Strength versus Endurance)

The term strength is defined as the maximum force a muscle can produce during a single exertion to create joint torque. The term endurance refers to the ability to maintain a force for a period of time. Muscle performance includes strength and endurance. The few studies available suggest that endurance has a much greater prophylactic value than strength.¹⁹ The emphasis should be placed on endurance and should precede strengthening exercises in a gradual, progressive exercise program (i.e., longer duration, lower effort exercises).

Sport-Specific Exercise

The physical therapist, trainer, physician, and coach must collaborate in designing a sport-specific rehabilitation program. New exercises should closely simulate the sport. Progress should be slow enough to develop an awareness of muscle function. The buildup to maximum performance requires time and patience.

Deep Water Running and Swimming

Walking in a swimming pool is a gentle strengthening exercise for the back. Deep water running is excellent for treating athletes with back pain. The buoyancy of the water helps to unload the spine. Athletes run in the deep end of a swimming pool, normally with the aid of a flotation vest. Water is about 800 times denser than air, so resistance met during water running is greater than when running on land. Deep water running can help to maintain aerobic performance for 6 weeks in trained endurance athletes; sedentary individuals can appreciate significantly increased maximal oxygen uptake. During spine rehabilitation programs, deep water running can be used for maintenance training, but deep water running is not a substitute for conventional training.²⁰^–²² Swimming is an excellent exercise for the back, but caution is advised for the novice. The swimming strokes can produce or exacerbate back injury if proper technique is not practiced.

Cycling

Although bicycling is generally considered a healthy form of non–weight-bearing, low-impact exercise, it is important to avoid prolonged flexion in a seated position. A more upright posture is easier on the intervertebral disc, so the upright mountain bike posture is preferred to the flexed racing bike posture. Avoiding the vibration of rough terrain is also logical, making stationary cycling a more reasonable option in the early stages of rehabilitation.

Program Guidelines

The following caveats should be considered when prescribing and monitoring any “return to sport” rehabilitation program ²³:

1 Low back exercises are most beneficial when performed daily.²⁴

2 The “no pain—no gain” approach when exercising the spine may cause tissue damage associated with certain specific repeated movements.²⁵

3 General exercise programs that include cardiovascular training (e.g., walking) have been shown to be effective for rehabilitation of individuals with low back pain and for injury prevention.²⁶

4 Intervertebral discs are more hydrated early in the morning after rising from bed; it is unwise to perform full-range spinal motions (bending) shortly after rising.²⁷

5 More repetitions of less demanding exercises assist in the enhancement of endurance and strength. Evidence indicates that endurance has more protective value than strength, and strength gains should not be overemphasized at the expense of endurance.¹⁹

6 There is no such thing as an ideal set of exercises for all individuals. Although science at present cannot evaluate the optimal exercises for each situation, the combination of science and clinical experience should be used to select an exercise program.

7 Individuals need to be patient and stick with the program. Increased function and pain reduction may not occur for 3 months in some individuals.²⁸

Education

Several studies have documented the value of patient education in the treatment of spine problems.²⁹ Education has been shown to be as valuable to the patient’s recovery as physical therapy. In 2004, Frost and colleagues²⁹ measured the effectiveness of routine physical therapy compared with a single assessment session and advice from a physical therapist for patients with low back pain. They used a multicenter, randomized controlled trial in seven British National Health Service physiotherapy departments. These authors concluded that routine physical therapy was no more effective than a single assessment and advice session from a physiotherapist in treating low back pain.

In the physician’s office, handouts are an excellent source of education and can be reference guides for the patient during rehabilitation activities (Table 29–1). Good preprinted handouts are available from multiple sources, such as the Krames (http://www.krames.com/) or the AAOS (http://www.aaos.org/) websites. Personalizing the handouts gives the athlete assurance in his or her provider’s interest and commitment to the rehabilitation plan and confidence in the treatment plan on leaving the office. With the availability of digital radiography, it is inexpensive to give the patient a copy of his or her radiograph to take home. Being educated regarding the nature of the injury and being part of the rehabilitation team, and not merely the subject, motivates the athlete and can bring about speedier and more complete recovery.

TABLE 29–1 Ways to Avoid Overuse Injuries

1. Use good technique	An overhand pitch produces less strain than a side-arm pitch
2. If it hurts, don’t do it	“No pain—no gain” is a poor concept. You feel the fatigue of a good workout, but you must recognize the pain of going beyond fatigue to injury
3. Stop when fatigued	Avoid the temptation of an extra repetition. Sprints are best done after a rest
4. Increase duration gradually	It takes time for the body to respond to increased demand and to strengthen
5. Rest for a time after major increases	It is better to alternate 3 hard days with an easy day and then rest for 2 days
6. Quit when you are tired	When you have exhausted the glycogen stored in your muscles, your technique falters, and you are prone to injury
7. Do preventive exercises	Keep your body in balance by stretching to gain full range of motion and loosening contractures
8. Remember your old injuries	When you recall your old injuries, you can work to avoid repeating them
9. Warm up slowly	Use gentle stretching and gradually increasing effort to limber up muscles and deep breathing to stimulate the heart and lungs

Return to Play

For the athlete, returning to play is a central issue and may be measured in terms of games missed as opposed to return of fitness. Generally, the athlete can return to play when there is no pain with sport-specific activities and when full range of motion and strength have been recovered. There is no definitive test to measure when that point is reached. Gradual improvement in pain and progression in performing functional activities are predictive of a good prognosis.

Disorders and Treatment

Low Back Pain in Adolescent Athletes

When a physician sees a child with back pain, he or she needs to rule out serious disorders, begin acute care, and anticipate a rehabilitation program that allows the child to return to normal physical activity. Careful evaluation is important; treatment is usually nonspecific. An open-ended interview to hear the patient’s story and expectations is the most valuable assessment instrument. Obtaining a detailed description of the pain is paramount.

The description of pain needs to include its location, duration, onset, and characteristic. If pain is associated with a particular activity or position, that information is helpful for diagnosis. Even with the most aggressive diagnostic workups and follow-ups, however, an organic cause for back pain in adolescents is found only about half of the time.

Lumbar spine pain or low back pain accounts for 5% to 8% of athletic injuries.³⁰ Injuries are often due to poor conditioning of the spine, poor biomechanics, or repetitive stresses placed on the spine by the nature of the sport. Overuse injuries from repeated lumbar hyperextension may be common in children participating in sports such as gymnastics, volleyball, and rowing.

Historical studies show that the correct diagnosis of acute low back pain is established on the first visit only 2% of the time. After 6 weeks, the diagnostic accuracy increases to 15%, and it increases to 30% at 3 months.³¹ The physician’s initial visit is best used to rule out serious disorders, such as disc herniation or malignant disease. Although less than 1% of back pain complaints are related to serious spine pathology or require emergent treatment, such as neoplasm or cauda equina syndrome, it is important to exclude these conditions and reassure the patient accordingly.

Aggressive diagnostic workup may be deferred and implemented only for patients who do not improve within 3 or 4 weeks. Often, pain resolves without much treatment, and the athlete continues participation. With severe or prolonged pain that prompts medical consultation, a diagnostic workup is appropriate for guiding the treatment.

Back pain that follows an acute injury is usually attributed to muscle strain. There is little scientific evidence showing muscle strain as a back pain generator, however, probably because pain produced by an injury cannot be differentiated to the various soft tissues of the back.³² The pain may be localized or diffuse. The patient frequently relates that more stiffness occurred after a night’s sleep. This type of back pain attributed to muscle strain tends to improve with time.

Growth is not linear, and as growth spurts occur, an imbalance between new length of bone and old length of muscles occurs. These contractures, whether of the hamstrings or other muscles adjacent to the spine, can produce limited motion and pain with athletic activities.

An adolescent with normal musculoskeletal structure may have back pain from poor standing and sitting posture. The typical profile is of lumbar hyperlordosis, thoracic hyperkyphosis, and contracted hamstrings. Radiographs are unnecessary to make the diagnosis or to institute a program of stretching and postural correction.

Mechanical backache secondary to poor posture is more common in sedentary children. Athletic children are less likely to report nonspecific back pain than their nonathletic counterparts. Children who do not walk to school and have a poor self-image of their health in general report more back pain. Multivariate analysis showed that the incidence of low back pain in adolescents is inversely related to time spent doing physical activity (e.g., regular walking or bicycling) and directly related to television or computer time.³³

Posture and inactivity contribute to low back pain. The intervertebral discs have the highest fluid content in the morning, which influences the pressure generated on spinal tissues during flexion.³⁴ Avoidance of flexion after arising in the morning significantly reduces nonspecific back pain.³⁵

Plain radiographs are indicated at the time of the first visit if there is a history of severe trauma, loss of neurologic function, or history of malignancy. For an adolescent athlete with a high-risk factor because of a repetitive hyperextension maneuver, oblique views are appropriate for evaluation of the pars interarticularis.

Spondylolysis

Spondylolysis is a stress fracture of the pars interarticularis. It is generally considered to be a low-risk fracture that heals on its own. The fracture occurs most frequently at L5, followed by L4 and L3. Spondylolysis occurs in 5% to 6% of the general population.¹ The lesion is usually asymptomatic and appreciated only incidentally on a radiograph. Generally, no single traumatic event causes spondylolysis; rather, repetitive stress produces fatigue defects, and a single event may complete the fracture. These fractures may develop fibrous nonunion or heal in an elongated state.³⁶

The incidence of pars defects is greater in adolescent athletes than in the general population and is a particular clinical problem for this population.³⁷ Sports that require repetitive hyperextension or extension combined with rotation such as gymnastics, wrestling, and weightlifting are more often associated with a stress fracture of the pars interarticularis. White female gymnasts experience a rate of spondylolysis (11%) five times that of the general white female population.³⁸ Certain participants in sports such as diving, weightlifting, wrestling, and gymnastics have disproportionately high rates of spondylolysis. A study of elite Spanish athletes showed the highest rates of spondylolysis in gymnasts and weightlifters followed by throwing athletes and rowers.³⁹ Other reports suggest that a wide variety of sports increase the risk of spondylolysis, including soccer, volleyball, and baseball.⁴⁰

A major concern for patients with defects in the pars interarticularis is the progressive development of symptomatic spondylolisthesis. The incidence of progressive spondylolisthesis is low (3% to 10%) and mainly occurs during adolescence.^41,⁴² There is no known correlation between active sports participation and either the occurrence or the progression of spondylolisthesis.