The term spondylolysis is derived from the Greek roots spondylo and lysis meaning vertebrae and loosening, respectively. The defect exists in the isthmic portion of the vertebral pars interarticularis, may be unilateral or bilateral, and typically occurs at the L4 or L5 level.1 With bilateral spondylolysis, slippage of one vertebra on another may be seen. This is known as spondylolisthesis.
The most common classification utilized for spondylolisthesis was initially described by Wiltse et al.2
- Type I: congenital or dysplastic
- Type II: isthmic
- IIA: lytic separation of pars
- IIB: elongated but intact pars
- IIC: acute pars fracture
- Type III: degenerative
- Type IV: traumatic
- Type V: pathologic
- Type VI: postsurgical
Although the etiology of spondylolysis is likely multifactorial, biomechanical stress and genetics play major roles. Repeated mechanical stress on the lumbar spine is thought to cause a fatigue fracture of the pars interarticularis. Age and ability to bear weight with walking may also contribute to the development of spondylolysis because the disease has not been described in newborns or nonambulatory children.3
Epidemiology including risk factors and primary prevention
- Prevalence varies with ethnicity: 54% Inuit, 6% to 11% white, and 2% black.3
- Peak prevalence of unilateral spondylolysis in the context of a specific malformation in young infants under age 4 with normal pelvic incidence, followed by a progressive incidence in the prevalence of bilateral isolated spondylolysis thereafter. 
- More common in gymnastics, weightlifting, football, and diving athletes.4
- Increased risk with spina bifida occulta or positive family history of spondylolysis.5
Prospective study examining the natural history of spondylolysis and spondylolisthesis revealed the following:
- Initial recruitment period (1954-1957) revealed 22 (4.4%) of 500 of the 6-year-old subjects had pars interarticularis defects (early defect group: 16 bilateral defects, 6 unilateral defects).
- Ten (62.5%) of 16 subjects with bilateral pars defects also had spondylolisthesis at the time of diagnosis.
- Follow-up period (1977-1979) revealed 30 (6%) of 500 participants had spondylolysis (late defect group: 22 bilateral defects, 8 unilateral defects).
- Fifteen (68.2%) of 22 subjects with bilateral pars defects were found to have spondylolisthesis.
- Final follow-up (1999) revealed that 3 additional subjects with bilateral spondylolisthesis from the early defect group had developed spondylolisthesis as adults.
- In all, 18 (81.8%) of 22 subjects with bilateral spondylolysis also had spondylolisthesis.6
Lumbar extension causes the inferior articular process of the cephalad vertebra to abut the pars interarticularis of the caudal vertebra.7 Repeated lumbar hyperextension and rotation required in certain sports impart repetitive stress to the incompletely ossified pars interarticularis of a growing child or adolescent. This may eventually lead to a stress reaction, followed by spondylolysis.8 A higher rate of spondylolysis in athletes may be attributed to repetitive lumbar hyperextension, with spondylolytic defects overwhelmingly occurring at the L5 vertebral level.4
The most common types of spondylolisthesis in the pediatric population are dysplastic (type I) and isthmic (type II).9 Isthmic spondylolisthesis occurs when the posterior elements are compromised because of a pars interarticularis defect, allowing one vertebral segment to slip in relation with an adjacent level. Dysplastic spondylolisthesis may develop secondary to conditions, such as dysplastic facet joints, spina bifida at L5 or S1, or various bone morphology abnormalities.3
Disease progression including natural history, disease phases or stages, disease trajectory (clinical features and presentation over time)
Spondylolisthesis can be quantified using the Meyerding grading system
- Grade I: displacement of 0% to 25%
- Grade II: displacement of 25% to 50%
- Grade III: displacement of 50% to 75%
- Grade IV: displacement of 75% to 100%
- Grade V: displacement greater than 100% (spondyloloptosis)10
Beutler et al6 studied the natural history of spondylolysis and spondylolisthesis in subjects over a 45-year period. The average slip progression was 7% in the first decade, 4% in the second and third decades, and 2% in the forth decade of follow-up evaluation. No increased rates of low back pain or disability as measured by the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) were identified compared with the general population. In fact, of the 30 original study subjects, only 1 episode of pain was noted.
In summary, the development of spondylolisthesis and its progression appear to be most prominent during growth spurts, with minimal progression occurring after skeletal maturity.11 However, even with bilateral pars defects, most pediatric patients will remain asymptomatic through adulthood.6
Spondylolysis with grade I spondylolisthesis: clinical follow-up
In a 2009 meta-analysis of nonoperatively managed patients, 83.9% of 665 patients had a satisfactory outcome after 1 year.12
Spondylolysis with grade I spondylolisthesis: radiographic follow-up
In the same meta-analysis, unilateral pars defects healed at a rate of 71.1% compared with bilateral defects at 18.1% after 1 year.12
Bilateral spondylolysis: incidence of spondylolisthesis and slip progression
In a study of 255 patients (in contrast with asymptomatic subjects in the observational study previously mentioned) between the ages of 9 and 40 years diagnosed with bilateral L5 spondylolysis with or without spondylolisthesis, results on initial evaluation were as follows:
- 19% had spondylolysis without spondylolisthesis
- 54% had grade I spondylolisthesis
- 27% had grade II spondylolisthesis or higher
After a minimum of 20 year follow-up, 91% of these patients had experienced low back pain at some point. Mean progression of vertebral slippage in adolescents (< 18 years) was 2.5 mm. In 11% of this adolescent population, progression was greater than 10 mm.13
Specific secondary or associated conditions and complications
High-grade spondylolisthesis (>50% slip on the Meyerding scale) can be associated with chronic back pain, radicular symptoms, neurogenic claudication, and disk degeneration.
2. ESSENTIALS OF ASSESSMENT
Important aspects to include in the history are as follows:
- Back pain onset, quality, severity, location, and radiation, and associated symptoms
- Neurologic involvement (including sensation changes, muscle weakness, bladder or bowel incontinence)
- Exacerbating and remitting positions and activities
- Participation in sports
- Previous diagnostic work-up, treatments, and response
- Family history
- Review of systems
In general, most patients with spondylolysis and low-grade spondylolisthesis have unremarkable physical examinations. Those with high-grade spondylolisthesis may have more concerning findings.
- Flattening of lumbar lordosis or sacral prominence may be noted in high-grade spondylolisthesis.8
- Tenderness over the fracture site may be seen with spondylolysis because of trauma.3
- Palpable step-off at a level of high-grade spondylolisthesis.
Range of motion
- Limited range of motion in all planes in acutely symptomatic patients. Pain and range of motion limitations usually worsened with spine extension .
- Hamstring tightness in symptomatic patients.3
- Normative neurologic exam is expected with spondylolysis and low-grade spondylolisthesis, whereas radicular symptoms and bladder or bowel dysfunction may be noted with high-grade spondylolisthesis.
- Straight-leg raise test may reveal nerve root irritation.
- Reproduction of ipsilateral back pain with 1-legged hyperextension (Stork test) is the most common and reliable physical exam finding for diagnosis of spondylolysis.4
In patients with high-grade spondylolisthesis, observation of gait in a clinical setting may reveal a shortened stride length and knee hyperflexion because of dysfunctional spinopelvic biomechanics and hamstring contracture, respectively.8
|Anterior-posterior||Standing flexion/extension films assess alignment and dynamic anterior-posterior instability.|
|Lateral||Vertebral displacement, slip angle, pelvic incidence, and the sacral inclination can be assessed via lateral view.|
Degree of vertebral displacement can be quantified using the Meyerding grading system.
|Oblique||May reveal a pars lesion that corresponds to a collar on the Scotty dog.|
|Imaging modalities||Indications/special aspects|
|Computed tomography||Compared with a plain radiograph, a computed tompgraphy scan is more sensitive in visualizing pars interarticularis lesions.14|
|Bone scan||Metabolically active bony lesions can be visualized with a bone scan. Although it suggested to be more sensitive than plain radiographs in early spondylolysis, bone scan findings are nonspecific.14|
|Magnetic resonance imaging (MRI)||Primarily indicated if neurologic signs/symptoms are present. The sensitivity of an MRI is comparable with that of a bone scan.15 In contrast with a bone scan, the MRI does not require administration of radioactive isotopes and does not use radiation. The MRI uniquely assesses disease chronicity; hyperintensity of the pars interarticularis on T2-weighted or short TI inversion-recovery sequences suggests an acute process.16|
At present, there are no established guidelines for advanced imaging modalities in patients with spondylolysis. In children, MRI is favored to bone scan and computed tomography because of the avoidance of radiation exposure. Bone scan remains the gold standard, and is the most sensitive imaging test . Additional imaging may be indicated if symptoms persist despite a course of conservative treatment.17
Early predictions of outcomes
Results of a retrospective study on the natural history of spondylolysis and spondylolisthesis indicated that pediatric subjects with spondylolysis do not appear to have an increased likelihood of disability or chronic pain in adulthood as assessed by a back pain questionnaire at the 25 year follow-up and the SF-36 at the 45 year follow-up.6
Social role and social support system
Spondylolysis typically begins in adolescence; therefore, parental education is important to ensure proper follow-up with health care providers. Athletes participating in gymnastics, weight lifting, soccer, and football are reportedly at a higher risk given repetitive flexion/extension movements of the spine.
3. REHABILITATION MANAGEMENT AND TREATMENTS
Available or current treatment guidelines
At present, there are no consensus guidelines for symptomatic spondylolysis treatment. Clinical recommendations are mostly based on expert opinion. Current practice commonly entails a trial of conservative management, including relative rest, avoidance of exacerbating activities, bracing, and physical therapy.6
At different disease stages
Spondylolysis and Low-Grade Spondylolisthesis (<50%)
- Cessation of sporting activity4
- Nonsteroidal anti-inflammatory drugs
- ± Immobilization (thoraco-lumbo-sacral orthosis or body cast for 8-12 weeks)8
- Initiate physical therapy (PT) after discontinuation of immobilization, e.g. using TLSO and the patient is able to perform pain-free lumbar extension. Initially, precautions should be in place to avoid spine extension .
- PT should include exercises focusing on activation and strengthening of deep abdominal and multifidus muscles5
- Transition from PT to home exercise program18
- Asymptomatic spondylolysis and/or low-grade isthmic spondylolisthesis do not require routine follow-up or imaging
- Symptomatic (pain, deformity, or hamstring muscle tightness) spondylolysis and/or low-grade isthmic spondylolisthesis require serial examinations
- Low-grade dysplastic spondylolisthesis requires routine examination and imaging every 4 to 6 months8
- Required in up to 15% of patients with spondylolysis and/or low-grade spondylolisthesis4
- Indications: refractory pain despite conservative management for a minimum of 6 months, new or progressive neurologic deficits, instability as conferred by multilevel pars defects8
- Procedures: in situ posterolateral fusion without instrumentation (criterion standard), direct pars repair19
High-Grade Spondylolisthesis (>50%)
- Surgical reduction and fusion with instrumentation19
Coordination of care
The physiatrist plays an important role in maintaining open communication within the treatment team, which also consists of a primary care physician, physical therapists, and in some cases, surgeons. The outlined treatment plan must be transparent; therefore, the family members, coaches, and athletic trainers are well informed.
Patient & family education
Generally, pediatric patients with asymptomatic spondylolysis or low-grade spondylolisthesis may participate in sporting activities. Additionally, patients may anticipate a benign course into the sixth decade of life with only a small group likely to develop symptoms secondary to slip progression.6
Treatment outcomes can be measured with the following tools:
- Pain scores (visual analog scale)
- Range of motion
- Back pain questionnaire
- Pediatric Quality of Life Inventory module for pain
- Pediatric Outcomes Data Collection Instrument
- SF-36 (in adults)
These are available tools that may be used in a clinical setting, but no studies specifically monitoring disease outcomes with these scales were found.
Translation into practice: practice “pearls”/performance improvement in practice (PIPs)/changes in clinical practice behaviors and skills
- Accurate diagnosis, including the type and classification of spondylolisthesis, is crucial to guide follow-up, treatment, and counseling.
- Surgery may be indicated in patients with progressive slippage, neurologic deficits, or intractable pain after 6 months of conservative management.
4. CUTTING EDGE/EMERGING AND UNIQUE CONCEPTS AND PRACTICE
5. GAPS IN THE EVIDENCE-BASED KNOWLEDGE
Gaps in the evidence-based knowledge
Further research must be undertaken to clarify appropriate use of imaging and to provide management guidelines for various stages of spondylolysis and spondylolisthesis. At present, data assessing efficacy of various braces, casting, and surgical procedures are limited.
- Logroscino G, Mazza O, Aulisa G, et al. Spondylolysis and spondylolisthesis in the pediatric and adolescent population. Childs Nerv Syst. 2001;17:644-655.
- Wiltse LL, Newman PH, Macnab I. Classification of spondylolysis and spondylolisthesis. Clin Orthop. 1976;117:23-29.
- Tsirikos AI, Garrido EG. Spondylolysis and spondylolisthesis in children and adolescents. J Bone Joint Surg. 2010;92:751-759.
- Standaert CJ, Herring SA. Spondylolysis: a critical review. Br J Sports Med.2000;34:415-422.
- McNeely ML, Torrance G, Magee DJ. A systematic review of physiotherapy for spondylolysis and spondylolisthesis. Man Ther. 2003:8;80-91.
- Beutler WJ, Fredrickson BE, Murtland A, et al. The natural history of spondylolysis and spondylolisthesis: 45-year follow-up evaluation. Spine(Phila Pa 1976). 2003;28:1027-1035.
- Farfan HF, Osteria V, Lamy C. The mechanical etiology of spondylolysis and spondylolisthesis. Clin Orthop Relat Res. 1976;117:40-55.
- Herman MJ, Pizzutillo PD. Spondylolysis and spondylolisthesis in children and adolescents. Orthopedic Knowledge Update 4 Spine 2012; Chapter 41:477-488.
- Lonstein JE. Spondylolisthesis in children. Cause, natural history, and management. Spine(Phila Pa 1976). 1999;24:2640-2648.
- Meyerding HW. Spondylolisthesis.J Bone Joint Surg. 1931;13:39-48.
- Fredrickson BE, Baker D, McHolick WJ, et al. The natural history of spondylolysis and spondylolisthesis. J Bone Joint Surg Am.1984;66:699-707.
- Klein G, Mehlman CT, McCarty M. Nonoperative treatment of spondylolysis and grade I spondylolisthesis in children and young adults: a meta-analysis of observational studies. J Pediatr Orthop. 2009;29:146-156.
- Saraste H. Long-term clinical and radiological follow-up of spondylolysis and spondylolisthesis. J Pediatr Orthop.1987;7:631-638.
- Harvey CJ, Richenberg JL, Saifuddin A, et al. The radiological investigation of lumbar spondylolysis. Clin Radiol.1998;53:723-728.
- Lusins JO, Eliting JJ, Cicoria AD, et al. SPECT evaluation of lumbar spondylolysis and spondylolisthesis. Spine(Phila Pa 1976). 1994;19:608-612.
- Ulmer JL, Mathews VP, Elster AD, et al. MR imaging of lumbar spondylolysis: the importance of ancillary observations. AJR Am J Roentgenol. 1997;169:233-239.
- Miller R, Beck NA, Sampson NR, Zhu X, Flynn JM, Drummond D. Imaging modalities for low back pain in children: a review of spondylolysis and undiagnosed mechanical back pain. J Pediatr Orthop. 2013;33:282-288.
- O’Sullivan PB, Twomey LT, Allison GT. Evaluation of specific stabilizing exercise in the treatment of chronic low back pain with radiologic diagnosis of spondylolysis or spondylolisthesis. Spine(Phila Pa 1976). 1997;22:2959-2967.
- Cheung EV, Herman MJ, Cavalier R, et al. Spondylolysis and spondylolisthesis in children and adolescents: II. Surgical management.J Am Acad Orthop Surg. 2006;14:488-498.
- Lemoine T, Fournier J, Odent T, et al. The prevalence of lumbar spondylolysis in young children: a retrospective analysis using CT. Eur Spine J. DOI 10.1007/s00586-017-5339-5. March 2007.
- Brukner, Bahr, Blair et al. Clinical Sports Medicine, 4th ed. Pp. 480-485. Pediatric spondylolysis and spondylolisthesis. McGraw Hill: 2007. North Ryde, New South Wales, Australia.
Katherine Yao, MD
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Yodit Tefera, MD
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Original Version of the Topic
David S. Cheng, MD, Craig Best, DO, and Kashif Saeed, MD. Pediatric Spondylolysis and Spondylolisthesis. Original Publication Date: 02/12/2014Original Version of the Topic