AUTHOR AND EDITOR INFORMATION

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• Introduction
• Clinical
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• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

INTRODUCTION

Section 2 of 11  

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• Introduction
• Clinical
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• Follow-up
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Background

Lumbar spondylolysis is a unilateral or bilateral defect of the pars interarticularis affecting one or more of the lumbar vertebrae.

The term is derived from the Greek words spondylos, meaning vertebra, and lysis, meaning break or defect. Numerous hypotheses have been proposed on the etiology of spondylolysis, as follows:

• Separate ossification centers

• Fracture during postnatal life

• Stress fracture (Arriaza, 1997; Morita, 1995)

• Increased lumbar lordosis

• Impingement of the articular process on the pars articularis

• Weakness of supporting structures (Aihara, 2000)

• Growth (Lonstein, 1999; Morita, 1995)

• Pathologic changes in the pars articularis

• Dysplasia of the pars interarticularis

However, mechanical factors are widely believed to be the cause or at least the trigger of the development of spondylolysis, especially when congenital abnormalities are present (Gans, 1998). Moreover, spondylolysis is argued to be related to the human erect posture and lumbar curve (Arriaza, 1997).

Ambulation may have a role in its genesis because no known cases exist in nonambulatory patients (Smith, 1999). As an acquired condition, no reports exist of its occurrence in stillborn fetuses or in the newborn (Dubousset, 1997). Heredity is also implicated (Albanese, 1982).

When the defect in the pars interarticularis is not associated with a forward displacement, the term spondylolysis applies (Stinson, 1993). Spondylolisthesis is from spondylos and listhesis, meaning movement or slipping, and refers to the slipping forward of one vertebra on the next caudal vertebra. Spondylolysis is most common at L5, accounting for 85% of all cases (Patel, 2000), and may be observed as high as L2 (Weiker, 1989). Therefore, a slip is most common at the level of L5 slipping forward on S1. Spondylolysis is the cause of the most common type of spondylolisthesis (Lonstein, 1999). Moreover, a case of spondylolysis that occurred at 3 sites in L5 involving the bilateral pars interarticularis and the center of the right lamina is reported (Ariyoshi, 1999).

Frequency

United States

Spondylolysis is more commonly observed in males (Patel, 2000), but this difference may not be significant (Commandre, 1998; Soler, 2000).

In the United States, a reported difference exists between the sexes and races, with an incidence of spondylolysis of 6.4% in white men, 2.8% in black men, 2.3% in white women, and 1.1% in black women. Pars defect is twice as common in boys than in girls, although high-grade slippage is 4 times more common in girls than in boys. Alaskan Eskimos (26%) have the highest incidence, with the highest rate in Eskimos from north of the Yukon River (Lonstein, 1999).

Functional Anatomy

Repetitive axial loading, especially in an extended lumbar spine is thought to be the most important contributing mechanism, leading to fatigue fracture of the pars interarticularis. Shear stresses on the isthmic pars are greater when the lumbar spine is extended. When repetitive extension stresses occur, the pars interarticularis becomes impinged from the inferior facet of the cephalad vertebrae, which results in microfractures and attempts at repair (Congeni, 1997).

Sport Specific Biomechanics

Spondylolysis occurs in 3-7% of the general population (Soler, 2000). The athletic population is believed to be more prone to the development of spondylolysis (Congeni, 1997) because its incidence in competitive athletes is higher than the percentage reported for the nonsports population (Rossi, 1990). The overall percentage of spondylolysis among athletes in a recent study is about 8%, a figure not significantly higher than that among the general population. However, certain sporting events were found to contribute higher percentages when each sport was considered separately, with the highest percentages occurring in throwing sports (26.67%), artistic gymnastics (16.96%), and rowing (16.88%) (Soler, 2000). In an earlier series, a high percentage of spondylolysis has been observed in diving (43.13%), wrestling (29.82%), and weightlifting (22.68%) (Rossi, 1990).

Other sports with high incidence rates of spondylolysis are ballet, dancing, football, volleyball, and fast bowlers in cricket. In ballet, the higher incidence rate is due in part to an inability to reach or maintain proper turn-out and thus overcompensation with lordosis.

In general, the presence of the repetitive actions of flexion, extension, rotation, and torsion, either alone or in combination, that are often associated with resistance are the biomechanical movements that show the highest prevalence of spondylolysis (Soler, 2000).

CLINICAL

Section 3 of 11  

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History

• Among the general population, most cases of spondylolysis are clinically inapparent, and spondylolysis is symptomatic in only 10% of patients (Soler, 2000). Many athletes with spondylolysis are likewise asymptomatic (Patel, 2000).
• Spondylolysis typically occurs in young people (Arriaza, 1997), with a mean age at diagnosis in athletes of about 15-16 years (Patel, 2000).
• Patients generally report low back pain aggravated by activity (Ralston, 1998), particularly with hyperextension maneuvers such as in gymnastics. In general, patients present without a history of neurologic symptoms (Weiker, 1989).

Physical

• The physical examination frequently yields minimal findings.
• • No tenderness to palpation is noted, but some discomfort can be elicited with deep percussion over the midline of the lumbar area.

  • Range of motion is full.

  • Because of the previously increased range of motion of dancers and gymnasts, they appear to have normal flexibility. Athletes suspected of having an injury must have their flexibility compared with that of the preinjury state.

  • Forward flexion does not increase symptoms.

  • Hyperextension mimicking the sporting movement generally elicits pain (Weiker, 1989).

  • Sciatica can occur but is rare (Omey, 2000).

  • Physical findings that may also be present include antalgic or normal gait, tight lumbar musculature and hamstrings, hyperlordosis, and buttock or thigh pain.

• If a unilateral defect is present, the 1-leg hyperextension test elicits pain on the involved side. This test is performed by the patient bearing weight on one leg with both the hip and knee of the other extremity flexed while hyperextending the lumbar spine (Weiker, 1989). The maneuver is performed on both sides, and asymmetric low back pain indicates unilateral disease. Bilateral disease may show symmetric or asymmetric pain with this maneuver (Ralston, 1998).
• The neurovascular examination findings are normal.
• The rest of the general low back pain examination must be performed, taking note of all dermatomes, myotomes, and reflexes (Omey, 2000).

Causes

• The repetitive actions of flexion, extension, rotation, and torsion, either alone or in combination, that are often associated with resistance are the biomechanical movements that show the highest prevalence of spondylolysis (Soler, 2000).
• In general, athletes may have an increased chance of having symptomatic spondylolysis. Whether the overall incidence is any different than the general population is unknown.

DIFFERENTIALS

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Other Problems to be Considered

Chronic or recurrent low back pain in the adolescent should indicate investigation of an underlying cause because idiopathic low back pain is rare in this age group in contrast to adults. Among the identified causes include the following (Patel, 2000):

Ankylosing spondylitis
Arthritis (eg, rheumatoid arthritis)
Aneurysmal bone cyst
Congenital anomalies
Diskitis
Disk herniation
Leukemia, lymphoma
Lumbar spine inflexibility
Lumbar hypermobility
Lumbosacral sprain
Osteoid osteoma
Osteoblastoma
Osteomyelitis
Osteosarcoma
Postural
Psychosomatic
Scoliosis
Scheuermann disease
Spondylolysis and spondylolisthesis
Spinal process apophysitis (Mannor, 2000)
Spinal stenosis
Schmorl nodes (Sward, 1992)
Trauma
Infections
Inflammations
Neoplasms (cancer)
Developmental abnormalities
Metabolic diseases
Degenerative disorders
Neurologic disorders
Referred pain
Psychological disorders
Miscellaneous

WORKUP

Section 5 of 11  

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Lab Studies

• No laboratory studies have been shown to aid in this diagnosis.

Imaging Studies

• Routine thoracolumbar radiography in an athlete should include anteroposterior (AP), lateral, and oblique views. Flexion and extension lateral radiographs can be added if spondylolisthesis is present or stability is in question.
• • AP radiographic findings are usually normal in spondylolysis (Omey, 2000).

  • The oblique views are particularly screened for the Scotty dog lesion in the pars interarticularis (Weiker, 1989). The pars defect is represented by the collar on the Scotty dog. Keep in mind that the oblique view must be of good quality and read by someone experienced in making the diagnosis. Considerable interobserver variation in making this diagnosis has been noted (Ralston, 1998).

  • The 30° cranially angulated AP view and the coned lateral view of the lumbosacral junction are proposed to display the majority of defects. Because the 30° cranially angulated AP view clearly depicts the pars interarticularis of L5 in the frontal plane, it also allows the distinction between unilateral and bilateral defects (Harvey, 1998). Suffice to say, plain radiography is used more to exclude unusual lesions and spondylolisthesis than to make the diagnosis of spondylolysis (Congeni, 1997).

• An athlete who is symptomatic with hyperextension and whose plain radiography results are normal requires additional investigations. A 99-m technetium ethylene diphosphonate bone scintigraphy identifies pars interarticularis stress fractures that were missed on oblique plain radiography. Those patients who have had recent trauma or strenuous activity and who are symptomatic show increased activity on the spondylolytic area. On the other hand, those with chronic low back pain show normal scans (Lowe, 1984).
• • The technetium bone scanning has its limitations (Bellah, 1991). When compared to the single-photon emission computed tomography (SPECT) scanning, the latter was found to be more sensitive and better at localization of abnormalities in those athletes with radiographically obvious spondylolysis/spondylolisthesis (Collier, 1985).

  • Bone scanning has a false-positive rate of 15% using CT scanning as the standard to establish the diagnosis of spondylolysis (Congeni, 1997). Therefore, SPECT scanning is needed to identify the more subtle stress reactions. Moreover, these scans can aid in establishing the acuity of the lesion or in identifying the site of the problem in an athlete with negative plain radiography results but whose clinical course is suggestive of a pars interarticularis fracture (Lowe, 1984). The main value of SPECT scanning lies in the identification of an acute stress reaction of the pars prior to its manifestation radiographically (Harvey, 1998).

• For more information about the defect in the bony structure involved, performing CT scanning through the fracture provides excellent detail. CT scanning also provides information regarding other features of spondylolysis such as facet joint changes, spondylolisthesis, and disc herniations, and it also helps prognosticate the potential for a lesion to heal (Elster, 1985). The technique for CT scanning is crucial because a lesion is optimally demonstrated when the plane of scanning is perpendicular to the plane of fracture. This is achieved if the CT scan gantry is reversed so that the scanning plane is perpendicular to the fracture (Harvey, 1998). CT scanning is not useful for impending stress fractures (Smith, 1999).
• MRI is inferior to CT scanning for direct visualization of defects of the pars interarticularis (Ulmer, 1997). However, MRI has utility to rule out disc herniations.

TREATMENT

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Acute Phase

Rehabilitation Program

Physical Therapy

The approach to the treatment of spondylolysis is based on the stage of the bony lesion as guided by radiography and nuclear medicine or SPECT scanning investigations as well as symptomatology (Weiker, 1989; Dutton, 2000). The complete healing of the bony lesion is the ultimate goal in treating patients with spondylolysis.

Acute phase: Some patients present with a spondylolytic defect on plain radiography and also have positive findings on bone scanning. This can represent a recent-onset defect on the pars interarticularis (Weiker, 1989) or a healing spondylolysis. Bracing and rest (Dutton, 2000) are the cornerstones of treatment for this type of lesion. Pain control and avoiding sports are also part of the acute phase or rehabilitation.

Physical therapy: A Boston overlapping brace is used to immobilize the pelvis for prevention of hyperextension and is worn in 0° lordosis for 23 hours per day and for as long as the patient is totally symptom free for a minimum of 3 months, after which a repeat bone scan is performed. Hamstring stretching and lumbar flexibility motions are performed in the brace. Most patients are said to have normal findings on scanning within 3-9 months (Weiker, 1989). Aquatic rehabilitation can also be performed in the acute phase.

Consultations

Consult neurosurgeons, orthopedic surgeons, neurologists, and physiatrists as indicated.

Recovery Phase

Rehabilitation Program

Physical Therapy

Recovery phase: The goals of this phase are the resolution of pain and the healing of the pars defect with either bony union or painless fibrous union if bony union is not possible.

Physical therapy: This phase of rehabilitation consists of a progressively shallower aquatic rehabilitation location so that graded gravitational forces are applied to the spine. Also, lumbar flexibility out of the brace as symptoms resolve is helpful, but inciting activities must still be avoided. Flexibility and strengthening of the paraspinal, iliopsoas, and abdominal muscles along with endurance training of the back (necessitated by deconditioning) are all especially important. One may advance to full participation in a brace as symptoms resolve.

Consultations

Consult neurosurgeons, orthopedic surgeons, neurologists, and physiatrists as indicated.

Other Treatment (Injection, manipulation, etc.)

Electromagnetic field therapy for persistent nonunion may be used in this phase.

Maintenance Phase

Rehabilitation Program

Physical Therapy

Maintenance phase: The single best predictor for a new injury during athletic activity is a history of a previous injury. Patients showing a spondylolytic defect on plain radiography but whose bone scanning result is negative are regarded as having an inactive spondylolytic defect (Weiker, 1989) or a pseudoarthrosis or old unhealed fracture (Dutton, 2000).

Physical therapy: Continue bracing for up to 6-9 months is indicated as necessary to heal the pars. These patients benefit from physical therapy that puts emphasis in deep abdominal muscles, specifically the internal oblique and transversus abdominis and the lumbar multifidus (O'Sullivan, 1997), in addition to flexibility exercises for the hamstrings and lower back. Hyperextension movements are avoided. One may need SPECT bone scanning or CT scanning to monitor healing.

Surgical Intervention

Some advocate surgery to prevent spondylolisthesis (Dutton, 2000).

Consultations

Consult neurosurgeons, orthopedic surgeons, neurologists, and physiatrists as indicated.

Other Treatment

Lumbar corsets and neoprene belts are also used (Weiker, 1989).

MEDICATION

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Tylenol (acetaminophen) and NSAIDs are the mainstays of pain control. Moreover, a short course of narcotic analgesics can help those who are in significant acute pain initially.

Muscle relaxants are overprescribed and have not been demonstrated to be of significant help.

Drug Category: Analgesics

Pain control is essential to quality patient care. Analgesics ensure patient comfort, promote pulmonary toilet, and have sedating properties, which are beneficial for patients who experience pain.

For the relief of moderate to severe pain, a short course of narcotic analgesic may be warranted. Opiates exert their effects by binding to different opioid receptors throughout the body, which produces a wide range of effects such as analgesia, euphoria, constipation, and respiratory depression.

Drug Category: Nonsteroidal anti-inflammatory drugs (NSAIDs)

Have analgesic, anti-inflammatory, and antipyretic activities. Their mechanism of action is not known, but they may inhibit cyclooxygenase (COX) activity and prostaglandin synthesis. Other mechanisms may exist as well, such as inhibition of leukotriene synthesis, lysosomal enzyme release, lipoxygenase activity, neutrophil aggregation, and various cell-membrane functions.

Drug Category: Muscle relaxants

Muscle relaxants are overprescribed and have not been demonstrated to be of significant help.

FOLLOW-UP

Section 8 of 11  

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Return to Play

Return to play is first begun with low-level sport activities after the follow-up visit at 4-6 weeks, after which gradual increase in intensity as tolerated is allowed under supervision (Moeller, 2001). Return to full activity is permitted only when patients are totally asymptomatic with full range of motion (Weiker, 1989). Patients must also have normal flexibility and normal strength and balance.

Complications

Complications include a progression to spondylolisthesis (ie, slippage of the vertebrae and its sequelae) as well as delayed diagnosis and nonunion with chronic pain.

Prevention

Because the etiology is unknown and factors that cause slippage are unknown, prevention suggestions are unavailable. However, athletes must be advised that preventing recurrences may prove difficult if they return to high-level competition.

Prognosis

If treatment is instituted early, lumbar spondylolysis can be successfully treated with conservative management (Morita, 1995). The cure rate for early spondylolysis with activity restriction and a thoracolumbosacral orthosis is 73%, while more advanced spondylolyses were found to be less responsive to this regimen (Morita, 1995).

With history and physical examination findings compatible with spondylolysis, athletes with normal findings on plain radiography and bone scanning are most likely to have pathology other than a pars defect. They are presumed to have a chronic back strain, and further investigation of the cause of the back pain is indicated while they are placed on physical therapy. Studies are repeated in 6-8 weeks if patients are still symptomatic with physical therapy (Weiker, 1989). MRI is appropriate in this setting (Dutton, 2000).

Surgical treatment is an option for persistently symptomatic patients who did not achieve bony healing with activity restriction and bracing (Buck, 1970; Morscher, 1984; Scott, 1987; Kakiuchi, 1997; Wu, 1999; Chen, 2000; De Gauzy, 2000). Bony union has also been reported with transcutaneous electrical stimulation in this group of patients (Fellander-Tsai, 1998).

Education

All athletes, especially those younger than 18 years, should know that not all sources of back pain are muscular and, therefore, should not be ignored if persistent. This is most important if the athlete is participating in gymnastics, football, dancing, or figure skating.

For excellent patient education resources, visit eMedicine's Back, Ribs, Neck, and Head Center. Also, see eMedicine's patient education article Back Pain.

MISCELLANEOUS

Section 9 of 11  

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Medical/Legal Pitfalls

• Misdiagnosis as benign back pain and progression to spondylolisthesis

Special Concerns

• Adults may have degenerative discs, facet arthrosis, or spinal stenosis along with spondylolysis, thus confounding treatment.
• An athlete younger than 18 years with low back pain has a 45% likelihood of having spondylolysis (Micheli, 1995).

MULTIMEDIA

Section 10 of 11  

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• Differentials
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• Miscellaneous
• Multimedia
• References

Media file 1:  Lumbosacral spondylolysis. Radiograph of L4 defect in the pars interarticularis.
	View Full Size Image
Media type:  X-RAY

Media file 2:  Lumbosacral spondylolysis. CT scan demonstrating defects in the left and right pars interarticularis.
	View Full Size Image
Media type:  CT

REFERENCES

Section 11 of 11

• Authors and Editors
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• Differentials
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Article Last Updated: Jul 22, 2005