AUTHOR AND EDITOR INFORMATION

Section 1 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

INTRODUCTION

Section 2 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

Background

Lumbar spondylolysis, a unilateral or bilateral stress fracture of the narrow bridge between the upper and lower pars interarticularis, is a common cause of low back pain (LBP) in adolescent athletes. The lifetime prevalence of LBP in those aged 11-17 years has been reported to be as high as 30.4% among adolescents participating in sports (Olsen, 1992). While a variety of disorders are likely responsible for these cases, lumbar spondylolysis must be considered in the differential diagnosis of LBP in this population.

Lumbar spondylolysis is a radiographic finding that is believed to develop, in most cases, during early childhood. Typically, it is not associated with any clinical symptomatology of significance, except in a particular subset of patients. This particular subset of patients is comprised of young and adolescent athletes participating in sports involving repetitive spinal motion, especially lumbar flexion/extension, and to a lesser degree, rotation.

Athletes who are involved in gymnastics, diving, weightlifting, wrestling, rowing, figure skating, dancing, volleyball, soccer, tennis, and football have been found to have a higher incidence of spondylolysis (Garry, 1998). The defect of the pars interarticularis is believed by most authors to represent a fatigue fracture caused by repetitive loading and unloading of this region of the vertebrae from physical activity. The natural history of the fracture appears to be relatively benign, and in most cases, there is no significant progression of the defect.

Spondylolysis can persist in some cases to become spondylolisthesis. Spondylolisthesis occurs when one vertebra slips forward in relation to an adjacent vertebra, usually in the lowest lumbar vertebral segment (L5). As a result, the L5 vertebral body slips forward on the S1 vertebral body. This also commonly occurs at the L4 and L5 levels. Spondylolisthesis is almost never due to trauma; it is usually discovered after a trauma or prolonged episode of back pain in an athlete prompts radiographic studies.

Most patients with either condition have excellent clinical outcomes with conservative measures, and surgical intervention rarely is necessary (Standaert, 2000). In selected cases, those patients unresponsive to nonoperative measures may benefit from surgical management. The approach to surgical management is dictated by the age of the patient and the degree of associated spondylolisthesis (Wu, 1999).

Frequency

United States

The incidence of isthmic spondylolysis varies according to different surveys, but it has been estimated to be approximately 3-6% in the general adult population. The incidence has been found to vary amongst different ethnic groups, possibly identifying genetic factors as having a degree of influence. Roche and Lowe examined 4200 cadaveric spines and found an overall incidence of 4.2%, with an incidence of 6.4% for Caucasian males, 2.3% for Caucasian females, 2.8% for African American males, and 1.1% for African American females. A study of Alaskan natives found the incidence to be 50% (Stewart, 1953). Lifestyle differences among cultural groups undoubtedly account for at least part of the difference in incidence among ethnic groups, and these findings must be treated with a degree of caution (Eisentein, 1978).

Most studies reveal that males consistently are affected 2-3 times as often as females and Caucasians are affected almost 3 times as often as African Americans. Most studies also show no significant change in incidence in individuals aged 20-80 years. Based on these studies, spondylolytic lesions generally are believed to occur in the early school-age years. A prospective study demonstrated a 4.4% incidence of spondylolysis in 500 first-grade children, which increased to an incidence of 6% in adulthood with a follow-up interval of 45 years (Beutler, 2003). The prevalence of spondylolytic lesions among adolescent athletes appears to be much higher than the prevalence among the general population. According to large-scale radiographic studies, the prevalence among adolescent athletes ranges from 8-15%, and among adolescent athletes referred for evaluation of back pain, this figure has been reported to be as high as 47% (Micheli, 1995).

A large screening study in Japan obtained from children who presented with LBP and who were participating in sports found that 32% of the patients younger than 19 years have at least one or more pars interarticularis defects (Morita, 1995). Morita et al investigated 185 adolescents younger than 19 years with spondylolysis and found 180 to be currently active in sports (Morita, 1995). Within competitive sports, increasing age and training more than 15 hours per week correlates with a higher incidence of spondylolytic defects (Duggleby, 1997). The most common level of a spondylolytic lesion is at the L5 level, estimated at 85-95%, followed by the L4 level, estimated at 5-15%.

Further evidence supporting the role of genetics as a significant factor was found by Fredrickson et al, who discovered an increased incidence of spondylolysis in fathers, mothers, and male siblings of affected people in their study (Fredrickson, 1984). As many as 26% of the immediate relatives of those with a demonstrable spondylolysis have been found to have a similar problem (Wiltse, 1962).

A strong association exists between lumbar spondylolysis and the presence of spina bifida occulta, which has been found to occur in 5-10% of the general population (Fredrickson, 1984; Roche, 1951; Bell, 1988). One theory is that spina bifida occulta may lead to instability of the lower lumbar segment, predisposing one to the development of pars interarticularis defects (Hoshina, 1980). Hyperlordosis of the lumbosacral spine, such as seen in Scheuermann kyphosis, has been associated with a higher incidence of spondylolysis (Ogilvie, 1987).

Spondylolysis is associated with spondylolisthesis in approximately 25% of cases; however, the progression of the spondylolisthesis to any significant degree generally is uncommon in those who participate in athletics and in those who do not participate in athletics. The tendency of progression of spondylolisthesis is correlated with the pubescent growth spurt; in a study involving a 20-year follow-up of 255 patients, the mean slip progression was 4 mm. Only 11% of adolescents and 5% of adults had slip progressions of greater than 10 mm in this radiological review.

Functional Anatomy

Spondylolysis is derived from the Greek word spondylo, which means vertebrae, and lysis, which means fracture. Spondylolysis is defined as a defect in the pars interarticularis of the vertebral arch. Often, it is described in association with spondylolisthesis, which can be found concurrently with spondylolysis. Spondylolisthesis is defined as the anterior or posterior displacement of a vertebral body on the one below it. These generally are described according to the following classification of Wiltse, Newman, and Macnab.

• Type I (dysplastic): Congenital abnormalities of L5 or the upper sacrum allow anterior displacement of L5 on the sacrum, which can occur with the pars interarticularis remaining intact.

• Type II (isthmic): A lesion in the pars interarticularis occurs. This type of spondylolysis is subclassified as a fatigue fracture (IIA), elongation (IIB), or acute fracture (IIC).

• Type III (degenerative): This type of spondylolysis is associated with long-standing segmental instability and alterations in the articular processes with associated remodeling of the articular process.

• Type IV (traumatic): Acute fractures of the vertebral arch occur in areas other than the pars.

• Type V (pathologic): This type of spondylolysis is due to generalized or focal bone disease affecting the vertebral arch.

This article focuses on isthmic spondylolysis as an independent entity from spondylolisthesis and its relationship to athletes, as this type of spondylolysis is a primary focus of concern in athletic adolescents.

CLINICAL

Section 3 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

History

The clinical presentation and reported findings of the historical examination of patients with spondylolysis may include the following:

• Although most patients with spondylolysis are asymptomatic, those who do develop symptoms typically present during the preadolescent growth spurt (Smith, 1999).
• Patients predominantly complain of focal LBP brought on by certain performance activities. Pain may be sharp and lancinating in the acute period or may become chronic, dull, and aching over time. The pain usually is of mild-to-moderate intensity. Pain may be located unilaterally or bilaterally, usually along the belt line. On occasion, the pain may radiate into the buttock or proximal lower extremity.
• The onset may be either insidious or acute. Often, mild symptoms may be present for a period of time, but then the symptoms may become exacerbated by a specific incident.
• Movements, particularly those involving spinal extension and to a lesser extent rotation, typically are described as exacerbating events. Pain often is improved with rest. One study showed up to 98% of adolescent patients with spondylolysis to have pain with extension and rotation movements of the spine (Blanda, 1993).

Physical

Common findings during the physical examination of a patient with spondylolysis may include the following:

• Upon inspection of the lumbar spine, a patient with LBP resulting from spondylolysis often exhibits a reduced lordotic posture with excessive hamstring tightness.
• The classically described Phalen-Dickson sign (ie, a knee-flexed, hip-flexed gait) may be demonstrated in patients with spondylolysis. Although this sign more often is seen in those with concomitant spondylolisthesis, it may be present regardless of the degree of vertebral slippage (Phalen, 1961).
• A gait pattern described as the pelvic waddle also has been described in association with spondylolysis. The hallmark of this gait abnormality includes a stiff-legged gait with a short stride length due to hamstring tightness.
• The clinician should also note the presence or absence of skin dimpling in the lumbosacral region that may signify the presence of spina bifida occulta, thereby raising the clinical suspicion of spondylolysis.
• Palpation of the overlying paraspinal region often produces tenderness, and there may be spasm of the paraspinal musculature causing splinting in acute cases (Garry, 1998). Take care to identify a possible "step-off" when palpating over the spinous process. This step-off is indicative of concomitant spondylolisthesis, particularly over the L5-S1 level.
• In assessing lumbar range of motion (ROM), forward flexion commonly is diminished secondary to hamstring tightness. Flexion typically does not increase symptoms, and in many cases, it provides relief. However, extension and rotation commonly cause discomfort for the patient.
• The preeminent physical examination maneuver thought to most reliably reproduce pain from spondylolysis is the one-legged hyperextension maneuver, also known as the stork test.
• • The patient is asked to stand on one leg and is brought backward into lumbar extension. Pain due to spondylolysis is thought to be elicited in unilateral lesions by standing on the ipsilateral leg.

  • While this maneuver most often is described in association with spondylolysis, it stresses other structures besides the pars interarticularis and can therefore be considered to be only suggestive of a pars interarticularis lesion within the context of the clinical picture.

• The neurological examination should include assessment of motor strength, sensation, and reflexes. The findings of the neurological examination should be within normal limits. Typically, radicular findings are absent in patients with isolated spondylolysis.

Causes

Spondylolysis is considered by most to represent a fatigue fracture resulting from repeated mechanical stress with microtrauma and eventual overload to the pars interarticularis rather than as a result of a single traumatic event (Wiltse, 1975). However, a traumatic event may result in the completion of a developing fracture (Wiltse, 1975). Studies have shown a remarkably low or absent rate of occurrence in newborns and very young children, as well as in those patients who have never been ambulatory.

Rosenberg studied 143 patients who had never walked, with an average age of 27 years, and found no cases of spondylolysis. This appears to support the theory that loading of the pars interarticularis during upright, weight-bearing activities plays a role in the pathogenesis of these lesions.

Another study investigating the mechanical loading of the spine tested cadaveric lumbar vertebrae that were cyclically loaded at the inferior articular processes simulating shear force. The authors found 55 of 74 vertebrae to sustain pars fractures. They concluded that the pars interarticularis was particularly vulnerable to this type of repetitive loading (Wiltse, 1975). Further analysis of the vertebrae of those subjects without a fracture revealed a larger cross-sectional area of cortical bone in the pars compared to the control group. This led the authors to hypothesize that a genetic predisposition may be related to the cortical bone density of the pars. This study also suggested that the strength of the neural arch may increase up to the 4th or 5th decade of life.

In an experimental model, Dietrich and Kurowski found that the greatest mechanical loads occur at L5 and S1 with flexion and extension movements. Furthermore, the greatest mechanical stress was found to occur at the region of the pars interarticularis. They also noted that the loads and stresses across this region are related to the physical dimensions of the vertebrae, which may offer a partial explanation to the varying incidence among different races and gender. Repeated flexion and extension maneuvers, and to a lesser degree rotation, typically have been thought to be the movements that are responsible for generating the forces across the pars interarticularis that result in spondylolysis (Cyron, 1978; Dietrich, 1985).

In a retrospective analysis of 213 young athletes, Gregory et al found left-sided lower lumbar pain was more common than right, and a marked increase in scintigraphic uptake was noted on the left side of the neural arch more often than the right side. Unilateral spondylolysis was identified by reverse gantry CT scanning on the left pars 36 times and on the right pars 16 times. These findings support the hypothesis that asymmetric repetitive movements associated with certain sports may be responsible for the development of unilateral spondylolysis (Gregory, 2005).

Green et al concluded from their cadaveric study on pars interarticularis stress investigating mechanical loading that activities involving alternating flexion and extension movements cause large stress reversals in the pars interarticularis, thereby creating the highest risk for developing a pars defect. They found compressive or axial loading to have little effect in generating these stresses likely responsible for spondylolysis (Green, 1994). Other anatomic studies have suggested that shear stresses on the isthmic pars are the greatest with lumbar spine extension (Letts, 1986).

The specific cause of LBP associated with spondylolysis and spondylolytic spondylolisthesis has not been definitively established. Theories include nerve root compression by floating laminae, intervertebral disc pain, lumbar facet joint pain resulting from spinal instability, or a combination of these pathologies (Edelson, 1986). A fibrocartilage mass of scar tissue forms at the site of lumbar spondylolysis and eventually develops into a structure frequently indistinguishable from a normal ligament by adulthood.

Eisenstein et al identified nerve fibers in the fibrocartilage masses histologically, and Nordstrom detected the existence of the slow-conducting type C pain fibers and substance P in spondylolytic tissue obtained from patients who underwent resection (Eisenstein, 1994; Nordstrom, 1994). Mechanoreceptors were later identified in these masses as well.

Hasegawa et al concluded that these fibrocartilage masses appear to be one source of pain, as LBP was induced by injecting hypertonic saline and was blocked by injecting lidocaine into these masses in all patients in their study prior to resection of the lesion. They hypothesized that the fibrocartilage mass plays a protective role by sensing instability through the mechanoreceptor and then conveying this information through nociceptive fibers as pain, while at the same time, stabilizing this area of instability by acting as a ligamentlike structure across the defect (Hasegawa, 1999).

Given the high number of asymptomatic spondylolytic lesions, an important issue that is lacking in the literature and warrants further investigation is determining the factors that are responsible for producing pain in one patient and not another.

DIFFERENTIALS

Section 4 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

WORKUP

Section 5 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

Lab Studies

• Laboratory studies are not indicated for diagnosing lumbosacral spondylolysis.

Imaging Studies

• Plain radiography



• • Traditionally, plain radiographs have been the hallmark of diagnostic imaging in cases of spondylolysis. The lateral oblique view, in which the pars interarticularis is best visualized, is described as having the appearance of a "Scotty dog." In isthmic spondylolytic lesions, the Scotty dog is described as having the appearance of a "collar" or a "broken neck," which is thought to be a pathognomonic finding (Standaert, 2000). In unilateral pars lesions, the contralateral region may demonstrate sclerosis secondary to the increased stresses in that area (Aland, 1986).
    
  
  
  • In studies comparing the different views of plain radiographs including anteroposterior (AP), lateral, and lateral oblique, 19% of pars interarticularis lesions were identified only on the lateral oblique view. Pierce reported the sensitivity of the AP view to be 32%, of the lateral view to be 75%, and of the lateral oblique view to be 77% (Pierce, 1987). The most sensitive view in one study was found to be the lateral spot view of the lumbosacral junction, which revealed 84% of pars interarticularis lesions.
    
  
  
  • Limitations of plain radiographs lie in the fact that to be optimally visualized, the lesion should ideally be aligned tangentially to the beam. Spondylolytic lesions often are not aligned within the plane of the standard 45 lateral oblique views. Although most authors support the belief that multiple views of the lumbosacral spine are necessary for optimal visualization of the pars interarticularis on plain radiography, the need for routine oblique radiographs has been questioned with concerns regarding increased radiographic exposure (Amato, 1984). Additionally, spondylolytic lesions seen on radiographs often are believed to represent an old injury that may not be symptomatic.
    
  
  
  • Flexion and extension lateral radiographs may be obtained if spondylolisthesis or spine instability is suspected.


• Single-photon emission tomography scan



• • In recent years radionuclide imaging studies, including planar bone scan and, more specifically, the single-photon emission computed tomography (SPECT) bone scan, have been found to be more sensitive than plain radiography in detecting pars lesions. Several authors comparing planar bone scan versus plain radiographs concluded that planar bone scans could potentially detect pars lesions earlier in the clinical course than could plain radiographs. Furthermore, it appears that bone scan may be more sensitive in differentiating pain-producing pars lesions from incidentally found lesions.
    
  
  
  • In a study by Lowe et al in 1984, a group of patients found to have spondylolysis on plain films were further imaged with a bone scan. A positive bone scan in each case correlated with the presence of LBP, while those with negative bone scans all were without pain. Similar results have been obtained in other studies, and it appears that bone scans may have a role in identifying those cases in which the spondylolytic lesion is the pain generator rather than just an incidental finding.
    
  
  
  • SPECT scans have been found to be more sensitive than either plain radiography or planar bone scintigraphy in detecting spondylolysis and have, for the most part, replaced planar bone scan as the radionuclide imaging study of first choice in suspected pars interarticularis lesions.
    
  
  
  • Studies carried out in 1988 and 1991 comparing plain radiography, planar bone scan, and SPECT scans by Bodner et al and Bellah et al, respectively, both found the SPECT scan to be more sensitive compared to the other 2 imaging studies. Furthermore, as with planar bone scans, SPECT scans may be helpful in detecting symptomatic pars lesions from asymptomatic lesions as they can identify metabolically active bone change. A particularly interesting study comparing the clinical outcome following surgery for pars interarticularis defects with SPECT scanning found that patients who became pain free after surgery have positive preoperative SPECT scans, while those in whom pain persisted after surgery had negative preoperative scans. This finding implies that those with negative scans may have been experiencing their symptomatology from a source other than the pars lesion.
    
  
  
  • A Japanese study was performed to clarify the role of SPECT scans. In this study, plain radiographs and SPECT scans were obtained in young patients (mean age 15.6 y) who had LBP and were clinically suspected of having spondylolysis. This study concluded that the SPECT scan primarily is indicated in patients with no apparent abnormality seen on plain radiograph and/or CT scan and who are still suspected of having spondylolysis from their history and physical examination. A positive study was thought to represent a stress reaction in the pars interarticularis, which may be amenable to rest and immobilization. A negative study at this point strongly suggests that spondylolysis is not the likely source of pain and may warrant further imaging to evaluate for a different pathology that may be causing symptomatology (Itoh, 1996).
    
  
  
  • Herring and Standaert offer the opinion that considering the relatively high radiation exposure one is subjected to in undergoing multiple views on plain film, along with the increased sensitivity of SPECT scan, the latter may be the most appropriate choice for the initial screening study. The authors feel with the advantages of SPECT, multiple plain radiographic views as an initial screening tool may not play a role in detecting spondylolytic lesions (Herring, 2001). In cases in which plain radiographs do reveal pars lesions, SPECT scan can be helpful in documenting the acuity of injury.
    
  
  
  • Interpretation of plain radiographs coupled with SPECT scan results
    
    
    • Table 1 outlines the interpretation of plain radiographs coupled with SPECT scan results.
      
    
    
    • Table 1 also offers treatment strategies based on these results, as followed by a British institution. These treatment strategies were outlined in a study conducted jointly by the Orthopaedic and Radiology departments investigating the role of SPECT scan in the management of patients with back pain and spondylolysis (Dutton, 2000).
      
    
    
    • While radionuclide imaging may have increased sensitivity in detecting pars defects compared to plain radiographs, they are not necessarily highly specific for this detection and have been found to yield positive results from pathologies other than spondylolysis, including infection and tumor such as osteoid osteoma and osteoblastoma.
      
      
    Outline of the Treatment Strategy Based on Results of Plain Radiographs and SPECT Scan in the Evaluation of Defects of the Pars Interarticularis in Patients Clinically Suspected of Having Symptomatic Pars Interarticularis Lesions

    Plain Radiograph	SPECT Scan	Interpretation	Management
    Negative	Negative	Pathology other than pars defect should be suspected	Further investigation of cause of back pain should be performed (eg, MRI)
    Negative	Positive	Early pars interarticularis fracture	Conservative management in form of rest, +/- bracing
    Positive	Healing	Spondylolysis	Conservative management in form of rest and bracing
    Positive	Negative	Pseudoarthrosis or old unhealed fracture	Consider surgical intervention for stabilization to prevent spondylolisthesis and to relieve pain. Consider further investigation to rule out alternative pathology.

  
  


• CT scan



• • As with the above mentioned radionuclide studies, CT scan has been found to be more sensitive than plain radiography in visualizing spondylolytic lesions (Harvey, 1998; Congeni, 1997).
    
  
  
  • In a study comparing plain radiography, CT scan, and bone scintigraphy (either bone scan or SPECT), CT scan was found to be more sensitive than plain radiographs and was found to be more specific than radionuclide imaging. Both standard axial views and reverse gantry CT imaging was used for this study, and the authors noted that some pars interarticularis defects were seen more clearly with one versus the other, though a direct comparison of views was not made.
    
  
  
  • CT scan has the added benefit of providing more detail about the nature of the pars interarticularis defect than bone scan or SPECT does. CT scan has the advantage of visualizing other spinal pathologies, most notably intervertebral disc pathology, which is not seen on the other radionuclide imaging studies. The relationship between CT scan and SPECT scan has not been fully established, and it is presently unclear as to which is the more sensitive study. The role of CT scan may be as an adjunctive study investigating the stage of healing in a pars fracture.


• MRI



• • MRI has not been studied as well as plain radiography, radionuclide scan, and CT scan. Initial studies revealed that MRI provides great difficulty identifying a normal intact pars interarticularis, resulting in a low positive predictive value.
    
  
  
  • MRI may be useful in detecting spondylolysis earlier in the clinical course than plain radiograph or CT scan do; this makes MRI comparable to radionuclide scan, while removing the disadvantages of radiation exposure. However, MRI typically has been associated with an excessively high rate of false-positive diagnoses (Yamane, 1993). Recent improvements in the technical aspects of MRI have increased its usefulness in imaging pars interarticularis lesions. T1 imaging with sagittal 3-mm slices has been shown to be most useful.
    
  
  
  • MRI offers some advantages. MRI is the criterion standard of imaging in most other lumbosacral spine pathologies. The lack of ionizing radiation makes MRI especially attractive for use on adolescent athletes.
    
  
  
  • The overall role of MRI has yet to be determined, as it is not clearly defined in the literature at this point. MRI is not a first-line imaging study in clinically suggested spondylolysis, but rather it is an adjunct study in evaluating for alternative pathologies.

TREATMENT

Section 6 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

Acute Phase

Rehabilitation Program

Physical Therapy

During the acute phase of rehabilitation for patients with spondylolysis, the focus is to reduce the pain. Instruction in posture and biomechanics with activities of daily living (ADL) can help to protect the injured pars, thus reducing symptoms, and preventing further injury. A period of rest for an average of 2-4 weeks can provide beneficial effects by modulating pain, decreasing inflammation, and decreasing the risk for further progression of a pars stress reaction to a frank fracture. Applying ice to the injured area for 20 minutes 3-4 times a day in conjunction with performing gentle ROM exercises and stretching of the quadriceps and hamstring muscles is strongly advised. Activity modification is recommended. The patient is advised to stop the activity or sport that evokes the back pain for an average of 2-4 weeks (Herring, 2001; Smith, 1999; King, 1999). In particular, the patient should avoid any activities involving hyperextension.

Bracing

Indications for the use of a brace are lack of symptom improvement by 2-4 weeks, the presence of a true fracture, the presence of a spondylolisthesis, the need for pain control, and the lack of patient compliance to activity restrictions (Seitsalo, 1991).

Currently, there are no randomized double-blinded studies of brace application in the treatment of spondylolysis; however, several authors have demonstrated good results. In 1985, a widely referenced study by Steiner and Micheli examined 67 patients with symptomatic spondylosis or low-grade spondylolisthesis via plain film or planar bone scan without a control group. A rigid antilordotic modified Boston brace was applied for 23 hr/day for 6 months, followed by 6 months of weaning. Follow-up at an average of 2.5 years demonstrated good or excellent results, and 23% showed bony healing on radiograph.

Furthermore, Blanda examined 62 patients with spondylolysis and found that 84% had excellent results with conservative treatment, which included using a lumbar brace, at an average follow-up of 4.2 years (Blanda, 1993). Overall, the results of bracing vary from complete healing with resolution of back pain to nonunion, persistence of pain, or progression to spondylolisthesis. Using return to sport as the end point, the success of bracing ranged widely from 7-84% (Ikata, 1996; Pizzutillo, 1989; Pettine, 1993; Micheli, 1980; Blanda, 1993).

In contrast to the above studies, several authors have reported on the treatment of patients with symptomatic spondylolysis using a soft brace or no brace instead of a rigid brace. In 1995, Morita studied 185 adolescents with spondylolysis and classified the pars defects into early, progressive, and terminal stages. Conservative management included the use of a conventional lumbar corset for 3-6 months. Follow-up radiographs showed healing without the use of a rigid brace in 73% of the patients in the early stage, in 38.5% of those in the progressive stage, and in 0% of those in the terminal stage (Morita, 1995).

In 1981, Jackson also examined 7 athletes with a positive bone scan with negative lumbosacral plain films and discovered that if the bony reaction was recognized early, healing at the subroentgenographic level could occur with rest and activity modification without using a brace (Jackson, 1981). Furthermore, Cogeni examined 40 young athletes diagnosed with spondylolysis on bone scan and followed a treatment protocol of nonrigid bracing, specific educational guidelines instructing patients to avoid hyperextension activities, flexibility training, strengthening, and cardiovascular activities. Only 2 out of 40 patients needed to switch to a rigid brace after 4 weeks due to persistent pain. None of the patients required surgical intervention at a follow-up period ranging from 3 months to 5 years (Cogeni, 1997).

Research on the biomechanical effects of bracing and its effect of immobilization on the spine has been performed. In 1992, Axelsson studied 7 patients following posterolateral lumbosacral fusions without internal fixation. These individuals were examined by roentgen stereophotogrammetric analysis in supine and erect positions one month postsurgery without lumbar support, with a molded rigid orthosis, and with a canvas corset with a molded plastic posterior support. Neither of the 2 types of lumbar support showed any evidence of a stabilizing effect on the sagittal, vertical, or transverse intervertebral translations.

Lantz also reviewed 4 trunk movements in 5 young men wearing a lumbosacral corset, a chairback brace, and a molded plastic thoracolumbosacral orthosis (TLSO) in standing and sitting positions. All 3 orthoses restricted some gross body motion, approximately one half to two thirds more than wearing no orthosis (Lantz, 1986). Both studies confirmed that a lumbosacral orthosis restricts gross motions of the trunk rather than intervertebral mobility in the lumbar spine.

Willems investigated whether plaster casts actually immobilize the lumbosacral joint. He studied 10 patients placed in a plaster cast. He examined the lumbosacral joint of these patients, using a 3-dimensional motion analysis system in static and dynamic test conditions. He found that plaster casting did decrease lumbosacral mobility during static test conditions and did not significantly decrease the mobility of the lumbosacral joint in dynamic test conditions (Willems, 1997). Hence, the most consistent effect of the lumbosacral orthoses appears to be the limitation of gross body motion. The rigid bracing seems to be the most effective.

Based on current literature, the need for bracing is limited. Bracing can be considered in patients who continue to have symptoms despite a period of rest. For most of these patients, nonrigid bracing is adequate.

Surgical Intervention

During the acute phase, it is the general consensus in the medical community to attempt conservative management prior to implementing surgical intervention. Many studies support the nonsurgical approach. In 1975, Wiltse demonstrated that 12 out of 17 young patients diagnosed with spondylolysis showed osseous healing with conservative treatment and no surgery (Wiltse, 1975). In 1985, Micheli and Steiner demonstrated radiologic healing in 18% of 67 patients with symptomatic spondylolysis or grade I spondylolisthesis (Steiner, 1985). Furthermore, Blanda examined 62 patients with spondylolysis and found 52 patients had excellent results with conservative treatment with an average follow-up of 4.2 years (Blanda, 1993). In a longitudinal study of young athletes with early detected spondylolysis and treated with conservative management, 29 of 32 respondents had good-to-excellent low back outcome scores at an average follow-up interval of 9 years (Miller, 2004).

Early diagnosis is an important factor for a good prognosis in bone healing. Ciullo and Jackson studied gymnasts and found that the longer the symptoms were present before treatment, the more likely that surgical intervention was needed (Ciullo, 1985). Jackson also examined 7 athletes with positive bone scans and negative lumbosacral plain films. Jackson discovered that if the bony reaction was recognized early, healing at the subroentgenographic level could occur with conservative treatment (Jackson, 1981). Furthermore, in 1995, Morita studied 185 adolescents with spondylolysis and classified the pars defects into early, progressive, and terminal stages. Conservative management produced healing in 73% of the early stage cases, in 38.5% of the progressive stage cases, and in 0% of the cases with terminal defects (Morita, 1995). These studies suggest that spondylolysis can successfully be treated using conservative treatment if diagnosed at an early stage.

Other Treatment

The use of external electrical stimulation for healing of spondylolysis has been reported in 2 cases in the literature.  Electrical stimulation has been used to heal fractures in all areas of the body.  Although the literature supports the efficacy of electrical stimulation in healing fractures, the use of electrical stimulation for healing of spondylosis is not well studied and generally not necessary (Stasinopoulos, 2004).

Recovery Phase

Rehabilitation Program

Physical Therapy

Once the LBP is controlled during the acute phase of treatment, a therapy program can be initiated. If the patient’s symptoms significantly decrease with rest and activity modification, a regimen of hamstring and hip flexor stretching, abdominal strengthening, lumbar flexion exercises, and cross-training with extension precautions can be instituted. If the patient requires the use of a brace, an initial program of hamstring stretching while wearing the brace can be started. As the symptoms continue to decrease, lumbar flexion exercises, abdominal strengthening, and hip flexor and hamstring stretching can be instituted without the use of the brace. Cross-training in nonextension activities can be performed, such as the stationary bike and hydrotherapy (Jackson, 1981; Morita, 1995; Wiltse, 1975; Steiner, 1985; Herring, 2001; Garry, 1998; Pizzutillo, 1989; Micheli, 1980; Cogeni, 1997; Axelsson, 1992).

These exercises eventually are incorporated into a more comprehensive rehabilitation program that includes spinal stabilization exercises. Spinal stabilization exercises help the patient in finding the neutral position of the spine, ie, the position that produces the least amount of pain. This position is dependent on the specific individual and is determined by the pelvic and spine posture that places the least stress on the elements of the spine and supporting structures. In classic spondylolysis pain, the neutral spine has a flexion bias. Dynamic lumbar stabilization exercises may be used to help provide dynamic muscular control and to protect the spine from biomechanical stresses, such as tension, compression, torsion, and shear (Kaul, 1994).

Surgical Intervention

See Maintenance Phase.

Maintenance Phase

Rehabilitation Program

Physical Therapy

The maintenance phase represents the final phase of the rehabilitation program. A home exercise regimen is prescribed and should be performed on a daily basis. An analysis of variables should be performed for each individual athlete so that further injuries can be prevented. Such variables include biomechanical errors, anthropomorphic features, posture, cardiovascular fitness, psychosocial factors, level of training, specific activities, medical pathology, and sports participation.

Biomechanical errors should be assessed with the specific requirements of the sport in mind. For example, movements in ballet dancing require maximal hip external rotation; therefore, a deficit may cause stretching of the abdominal muscles and thereby increase lumbar lordosis. Consequently, increased stress on the posterior elements of the spine may occur (Kaul, 1994; Hald, 1992).

Anthropomorphic features involve looking at predictive factors that may lead to back injury. For example, hypermobility of the spine in lumbar extension in female gymnasts may be predictive of back injuries (Steele, 1986; Nadler, 2000; Nadler, 1998). The posture of the athlete in the specific sport also is important to analyze, since it is well known that hyperextension of the back can cause increased stress on the posterior elements of the spine. A tight hip flexor muscle also can cause increased stress on the spine since it arises from the sides of the intervertebral disks and the adjacent ends of the vertebral bodies from T12-L4 and from the transverse processes of all the lumbar vertebrae (Hollinshead, 1985).

Intramuscular EMG recordings have shown that the only lumbar movement that consistently recruits the hip flexor is a deliberate increase in lumbar lordosis while standing erect (Basmajian, 1985). Therefore, if this muscle is tight, it can promote an increase in lumbar lordosis and, hence, increased stress on the posterior elements of the spine. Another study also showed an association of LBP with tight hip flexors (Kujala, 1992).

Cardiovascular fitness also should be stressed in order to increase endurance and decrease fatigue. Psychosocial factors also are important to incorporate into the maintenance phase, since pain can be magnified by depression.

Medical pathology should also be evaluated, especially in female athletes who are at risk for the female athlete triad, which includes disordered eating patterns, amenorrhea, and osteoporosis. Eating disorders include anorexia nervosa and bulimia nervosa. The prevalence of eating disorders in female athletes is 5-10% higher than in female nonathletes, and some reports indicate the prevalence is as high as 15-62% (Hoch, 2001). The prevalence of primary amenorrhea is reported to be as high as 4-66% in female athletes, compared to 2-5% in the general population (Hoch, 2001). Amenorrhea is postulated to occur as a result of poor diet and excessive exercise, which can cause hormonal changes that inhibit ovulation. Consequently, with low estrogen levels, early osteoporosis can occur; therefore, the risk for fracture is increased in this population.

Sports participation also should be examined. For instance, the athlete may be involved in more than one sport. The above variables also should be carefully analyzed for the second sport. Regardless of the sport, maintenance of proper spine positioning during play should focus on spinal stabilization and maintaining a neutral spine. The program should progress to a functional exercise regimen and then to sport-specific training. In general, the abdominal, gluteal, and back extensor muscles are the key muscles to strengthen and build endurance.

Surgical Intervention

Indications for surgery include (1) persistent pain unrelieved by rest and immobilization for more than 6 months, (2) progression to spondylolisthesis, (3) spondylolisthesis of greater than grade II in a patient about to undergo the preadolescent growth spurt, and (4) any significant neurologic abnormalities (King, 1999; Garry, 1998; Omey, 2000). As discussed above, the prognosis of bone healing is dependent on the stage of the spondylolytic lesion (Morita, 1995). In 1997, Dubousset reported that if treatment is delayed for 3 months or more after the fracture occurs, nonoperative treatment is unsuccessful (Dubousset, 1997). Surgical options include direct repair of the spondylolytic defect, fusion in situ, reduction and fusion, and vertebrectomy.

Ideal candidates for direct repair of the pars defect are those with early lesions, with lysis but no listhesis, and with the lytic defect between L1-L4. L5 lytic defects have been reported to yield less predictable results due to the fact that many L5 defects occur because of developmentally weakened and elongated pars (Smith, 1999). Surgical techniques generally employ debridement of the lytic defect, application of large amounts of autogenous iliac crest cancellous bone graft, and tension band wiring or screw fixation from the cephalad portion of the posterior element to the free-floating caudal fragment. Bone healing of 75% to greater than 90% and symptomatic relief in 70-90% of the patients have been reported with the screw fixation technique (Pederson, 1988; Roca, 1989). Tension band wiring with 73-100% bony union has been reported (Smith, 1999; Morscher, 1984).

Ideal candidates for a fusion-in-situ procedure are patients with a low-grade spondylolisthesis that remains symptomatic despite nonoperative measures or with high-grade spondylolisthesis with acceptable sagittal balance. Reports of fusion rates of 83-95% and good or excellent results in 75-100% of the patients have been reported (Newton, 1997; Wiltse, 1976).

Decompression and fusion are indicated when severe neurologic signs of compression are present, such as radiating leg pain, numbness, and weakness with corresponding imaging studies demonstrating nerve root or thecal sac compression. Reduction is indicated to prevent the complications of progression of slip, pseudoarthrosis, and cosmetic deformity associated with in-situ fusion; hence, reduction of high-grade slips often is performed. Reduction (closed or open) serves to correct lumbosacral kyphosis and to diminish the sagittal translation seen in high-grade slips. Also, correction of lumbosacral kyphosis decreases the compensatory hyperlordosis above the fusion site (Smith, 1999).

Spondyloptosis, complete slippage of one vertebra on the next lower vertebra, is an indication for vertebrectomy. This condition has a high rate of neurologic dysfunction, such as cauda equina syndrome. The Gaines procedure (stage 2) commonly is used. The first stage is anterior resection of the L5 vertebral body. Several days later, the second stage involves posterior resection of the remainder of the L5 pedicles and posterior elements after distraction via Harrington outriggers. Pedicle screws are placed in L4 and S1, and reduction is performed. This procedure is associated with iatrogenic neurologic deficits due to the preexisting neurologic dysfunction from the slipped vertebra. Reports of 25-30% of patients developing neurologic deficits postoperatively have been reported (Smith, 1999).

Complications of surgery include disk degeneration adjacent to previously fused segments; however, Szypryt reported that disk degeneration, either at the disk or adjacent disk, was uncommon in patients younger than 25 years (Schelegel, 1996). In fact, they found that patients who are older than 25 years and who are not treated developed a higher prevalence of disk degeneration at the deranged motion segment as well as the adjacent segment when compared to age-matched healthy patients (Szypryt, 1989). Other complications include slip progression after surgery and iatrogenic neurologic deficit (Smith, 1999).

Consultations

A consult to a spine surgeon may be indicated if conservative management is unsuccessful.

MEDICATION

Section 7 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

Medications recommended for treatment of pain in spondylolysis include nonsteroidal anti-inflammatory drugs (NSAIDs), acetaminophen, and muscle relaxants. Before prescribing these medications, review the contraindications, adverse side effects, and mode of action.

Drug Category: Nonsteroidal anti-inflammatory drugs

Have analgesic, anti-inflammatory, and antipyretic activities. Their mechanism of action is not known, but may inhibit cyclo-oxygenase 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

Help to relax the tight muscles and can be used in conjunction with NSAIDs.

Drug Category: Analgesics

Pain control is essential to quality patient care. Analgesics ensure patient comfort and have sedating properties, which are beneficial for patients who have sustained injuries.

FOLLOW-UP

Section 8 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

Return to Play

Return to play protocol depends on the individual's progress and the stage of the pars injury. Herring recommends that the athlete progressively return to the sport if he/she is asymptomatic after 4-6 weeks with a mature corticated fracture on CT scan. According to Herring, if the CT scan shows an earlier stage lesion with either a stress reaction or minimal separation with noncorticated or cystic margins, the potential for true bone healing exists and he recommends a more extensive rest protocol of 12 weeks, with no participation in sports and no extensive physical activity beyond that associated with normal daily activities. After a gradual rehabilitation program and no symptoms, the athlete can progressively return to the sport (Herring, 2001).

Cogeni recommends that after 8 weeks from the diagnosis, the athlete can return to play if he/she has been pain free during therapy, at rest, with hyperextension, and with the specific athletic activity (Cogeni, 1997). Omey and Micheli recommend that with early spondylolytic lesions, a rigid brace be applied for 6-9 months before returning to the sport. The athlete must be pain free when playing the sport with the brace applied before discontinuing its use (Omey, 2000).

In general, there is no official time guideline for return to play in the literature; however, the general consensus for return to play is for the athlete to be asymptomatic at rest, with activity, with hyperextension, and when playing the specific sport.

Prevention

See Physical Therapy, Maintenance Phase.

Prognosis

In general, early lesions have a greater chance for true bony healing. Early lesions usually yield good to excellent results. The chronic lesions have a decreased chance for true bony healing; however, even without complete bony union, the symptoms can resolve with proper therapy, rest, and sport-specific techniques.

Education

Overall, patient education in prevention of low back injuries is important. Maintaining proper flexibility and spinal stabilization with a home exercise program also are strongly advised. Teaching proper technique in the specific sport also can prevent recurrence of back injury. Seasonal athletes should be encouraged to cross-train year round or undergo preconditioning before participation in the sport.

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

REFERENCES

Section 9 of 9

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• References

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