THE ETIOLOGY OF SPONDYLOLISTHESIS

Prevalence and risk factors of lumbar spondylolisthesis in elderly Chinese men and women

OBJECTIVE

A screening survey for osteoporotic fractures in men and women in Hong Kong represents the first large-scale prospective population-based study on bone health in elderly (≥65 years) Chinese men and women. This study aims to identify the prevalence and potential risk factors of lumbar spondylolisthesis in these subjects.

METHODS

The lateral lumbar radiographs of 1,994 male and 1,996 female patients were analysed using the Meyerding classification.

RESULTS

Amongst the men, 380 (19.1%) had at least one spondylolisthesis and 43 (11.3%) had slips at two or more levels; 283 had anterolisthesis, 85 had retrolisthesis, whereas 12 subjects had both anterolisthesis and retrolisthesis. Amongst the women, 499 (25.0%) had at least one spondylolisthesis and 69 (13.8%) had slips at two or more levels; 459 had anterolisthesis, 34 had retrolisthesis, whereas 6 subjects had both anterolisthesis and retrolisthesis. Advanced age, short height, higher body mass index (BMI), higher bone mineral density (BMD) and degenerative arthritis are associated with spondylolisthesis. Lower Physical Activity Scale for the Elderly (PASE) score was associated with spondylolisthesis in men; higher body weight, angina and lower grip strength were associated with spondylolisthesis in women.

CONCLUSION

The male/female ratio of lumbar spondylolisthesis prevalence was 1:1.3 in elderly Chinese. Men are more likely to have retrolisthesis.

KEY POINTS

• The prevalence of spondylolisthesis is 19.1% in elderly Chinese men. • The prevalence of spondylolisthesis is 25.0% in elderly Chinese women. • Men are more likely to have retrolisthesis. • Anterolisthesis is most commonly seen at the L4/L5 level. • Retrolisthesis is most commonly seen at the L3/L4 level.

Radiologic evaluation of degeneration in isthmic and degenerative spondylolisthesis

Study Design

A cross-sectional imaging study.

Purpose

The objective was to assess the degree of degeneration and the associated factors through imaging studies of the lesion segment and the adjacent superior and inferior segments of isthmic and degenerative spondylolisthesis.

Overview of Literature

Few articles existed for degeneration and related factors in isthmic and degenerative spondylolisthesis.

Methods

The subjects were 95 patients diagnosed with spondylolisthesis. Simple plain radiographs including flexion and extension and magnetic resonance imaging were used to investigate the degree of translation, disc degeneration, high intensity zone (HIZ) lesion, Schmorl's node (SN) and Modic changes.

Results

Advanced disc degeneration, grade 5, was shown to be significant in the index segment of the isthmic type (p=0.034). Overall, type 2 Modic change was most common in both groups and also, it was observed more in the isthmus group, specifically, the index segment compared to the degenerative group (p=0.03). For the SN, compared to the degenerative type, the isthmus type had a significantly high occurrence in the index segment (p=0.04). For the HIZ lesions, the isthmus type had a higher occurrence than the degenerative type, especially in the upper segment (p=0.03).

Conclusions

Most advanced disc degeneration, fifth degree, SN and Modic change occurred more frequently in the lesions of the isthmus type. HIZ lesions were observed more in the isthmus type, especially in the segment superior to the lesion.

Experiencia del tratamiento de espondilolistesis lumbar degenerativa de un solo segmento con espaciador interespinoso

OBJETIVO: Evaluar a un año el resultado del uso de espaciadores dinámicos en listésis grado I de Meyerding utilizando la escala de incapacidad de Oswestry. MÉTODOS: Se revisa el historial electrónico y radiográfico de los pacientes según criterios en el período de enero 2008 a diciembre 2010, con el propósito de realizar un estudio de cohortes, retrospectivo, longitudinal y observacional. RESULTADOS: El Oswestry prequirúrgico fue de 3.4% leve, 55.2% moderado y 41.4% severo; mientras que el posquirúrgico fue de 79.3% leve y 20.7% moderado. La cirugía realizada más común fue exploración y liberación con un 72.4%, presentando discectomía únicamente el 27.6%. Los pacientes presentaron dolor irradiado a miembro pélvico derecho en el 37.9%, miembro pélvico izquierdo 44.8% y a ambos miembros pélvicos en un 17.2%. Se presentó dolor posquirúrgico irradiado a miembro pélvico únicamente en el 2.4% siendo que el 100% de los casos presentaron algún tipo de dolor irradiado. Se utilizó espaciador DIAM en 79.3% y Wallis en 20.7% CONCLUSIONES: El tratamiento con espaciador interespinoso presenta un bajo índice de reintervención y por lo menos a un año presenta mejoría significativa en el índice de incapacidad.

Osteoarthritis of the spine: the facet joints

Osteoarthritis (OA) of the spine involves the facet joints, which are located in the posterior aspect of the vertebral column and, in humans, are the only true synovial joints between adjacent spinal levels. Facet joint osteoarthritis (FJ OA) is widely prevalent in older adults, and is thought to be a common cause of back and neck pain. The prevalence of facet-mediated pain in clinical populations increases with increasing age, suggesting that FJ OA might have a particularly important role in older adults with spinal pain. Nevertheless, to date FJ OA has received far less study than other important OA phenotypes such as knee OA, and other features of spine pathoanatomy such as degenerative disc disease. This Review presents the current state of knowledge of FJ OA, including relevant anatomy, biomechanics, epidemiology, and clinical manifestations. We present the view that the modern concept of FJ OA is consonant with the concept of OA as a failure of the whole joint, and not simply of facet joint cartilage.

Facet joints arthrosis in normal and stenotic lumbar spines

STUDY DESIGN

A descriptive CT study of lumbar facet joint (FJ) arthrosis in general and spinal stenosis populations.

OBJECTIVE

To reveal the prevalence of FJ arthrosis in general and stenosis populations and to establish its relationship to age and sex.

SUMMARY OF BACKGROUND DATA

FJ arthrosis is a common radiographic finding and has been suggested as a cause of low back and lower extremity pain. It is also considered a dominant player in the genesis of lumbar spinal stenosis. Although it is well accepted that FJ arthrosis is an age dependent phenomenon, controversies still exist as to its association with sex and its prevalence at different spine levels. In addition, data on FJ arthrosis frequency in spinal stenosis population are missing.

METHODS

Two groups were studied. The first included 65 individuals with LSS (mean age = 66 ± 10 yr) and the second, 150 individuals (mean age = 52 ± 19 yr) without LSS related symptoms. Both left and right FJ arthrosis for each vertebral level (L3-S1) were evaluated on CT images (Brilliance 64, Philips Medical System, Cleveland, OH). Chi-square, Linear-by-Linear Association and McNemar test were carried out to reveal the correlation between FJ arthrosis and demographic factors (age, sex) and prevalence at different lumbar levels in both stenosis and nonstenosis groups. In addition, a two-way analysis of variance (ANOVA) was used to determine the association between body mass index (BMI) and FJ arthrosis.

RESULTS

The rate of FJ arthrosis at L3-L4 and L4-L5 were significantly higher (P < 0.001) in the stenotic group compared to the control. In the control group the prevalence of FJ arthrosis increases cephalocaudally (L3-L4 = 16%, L4-L5 = 28%, L5-S1 = 55%), whereas in the stenotic group there is a sharp increase from L3-L4 (27%) to L4-L5 (58%), but not from L4-L5 to L5-S1 (55%). No association between FJ arthrosis and sex was noted. Although, mean BMI was significantly smaller in the control group compared to the stenotic group, no association between BMI and facet arthrosis was found. In the general population the prevalence of FJ arthrosis at all three levels was greater for the right side; however, significant difference (P = 0.004) was obtained only for L3-L4. In all joints studied, the prevalence of FJ arthrosis increases considerably from the young age cohort (18-39) to the old age cohort (>60). Nevertheless, 10% of the young individuals (18-39) have already manifested FJ arthrosis at L5-S1. No arthrosis at that age was observed at L3-L4.

CONCLUSION

FJ arthrosis is an age-dependent and BMI and sex independent phenomenon. In the general population, the prevalence of FJ arthrosis increases cephalocaudally with the highest frequency at L5-S1. In the stenotic group, the highest frequency was observed at the two caudal levels; L4-L5 and L5-S1. The prevalence of FJ arthrosis was greater for the right side.

Correlation between disability and MRI findings in lumbar spinal stenosis: a prospective study of 109 patients operated on by decompression

BACKGROUND AND PURPOSE

MRI is the modality of choice when diagnosing spinal stenosis but it also shows that stenosis is prevalent in asymptomatic subjects over 60. The relationship between preoperative health-related quality of life, functional status, leg and back pain, and the objectively measured dural sac area in single and multilevel stenosis is unknown. We assessed this relationship in a prospective study.

PATIENTS AND METHODS

The cohort included 109 consecutive patients with central spinal stenosis operated on with decompressive laminectomy or laminotomy. Preoperatively, all patients completed the questionnaires for EQ-5D, SF-36, Oswestry disability index (ODI), estimated walking distance and leg and back pain (VAS). The cross-sectional area of the dural sac was measured at relevant disc levels in mm², and spondylolisthesis was measured in mm. For comparison, the area of the most narrow level, the number of levels with dural sac area < 70 mm², and spondylolisthesis were studied.

RESULTS

Before surgery, patients with central spinal stenosis had low HRLQoL and functional status, and high pain levels. Patients with multilevel stenosis had better general health (p = 0.04) and less leg and back pain despite having smaller dural sac area than patients with single-level stenosis. There was a poor correlation between walking distance, ODI, the SF-36, EQ-5D, and leg and back pain levels on the one hand and dural sac area on the other. Women more often had multilevel spinal stenosis (p = 0.05) and spondylolisthesis (p < 0.001). Spondylolisthetic patients more often had small dural sac area (p = 0.04) and multilevel stenosis (p = 0.06).

INTERPRETATION

Our findings indicate that HRQoL, function, and pain measured preoperatively correlate with morphological changes on MRI to a limited extent.

Posterior listhesis of a lumbar vertebra in spinal tuberculosis

The management of spinal tuberculosis, especially in children, is controversial. In children, vertebral destruction is more severe than adults because of the cartilaginous nature of their bone. Modern chemotherapy has significantly decreased mortality in spinal tuberculosis, but morbidity remains high. Without early surgery, patients can develop severe kyphosis leading to respiratory insufficiency, painful costopelvic impingement and paraplegia. Lumbar kyphosis results in early degenerative lumbar canal stenosis and is cosmetically unacceptable. We report a paediatric case of atypical spinal tuberculosis demonstrating the need for early surgical intervention to prevent significant spinal instability and neurologic deficit. A 12-year-old girl presented with increasing ambulatory difficulty and double incontinence 4 months after initiating treatment for pulmonary tuberculosis. There was no history of traumatic injury. Examination revealed severe lower limb neurologic deficit, with hypotonia, areflexia, marked sensory loss, and grade 0/5 power in both lower limbs. Plain radiographs and magnetic resonance imaging (MRI) demonstrated grade IV posterior listhesis of the L2 vertebral body over L3, cauda equina compression and bilateral psoas abscesses. Erosion of both the body and pedicle of L2 was observed. Both serology and pus drained from the psoas abscesses were negative for microorganisms. The patient underwent an L2 vertebrectomy via a left retroperitoneal approach. A titanium cage packed with autologous bone graft was inserted, and the spine was stabilized by fixation with screw and rods. Histopathology confirmed a diagnosis of tuberculosis. Eighteen months following the procedure, the patient has regained some power in her right leg and has completed her course of anti-tuberculous chemotherapy, but remains wheelchair-bound. To our knowledge, this is the first reported case of posterior listhesis secondary to spinal tuberculosis. Here, we discuss the possible management options in such a case, and the indications for surgery. As the global HIV/AIDS epidemic causes a resurgence in tuberculosis, increased awareness among the medical community regarding the atypical presentations of spinal tuberculosis is necessitated; both in the developing world where advanced clinical presentations are common, and in the developed world where spinal tuberculosis is an often-neglected diagnosis.

Spondylolysis and spondylolisthesis in children and adolescents

A review of the current literature shows that there is a lack of consensus regarding the treatment of spondylolysis and spondylolisthesis in children and adolescents. Most of the views and recommendations provided in various reports are weakly supported by evidence. There is a limited amount of information about the natural history of the condition, making it difficult to compare the effectiveness of various conservative and operative treatments. This systematic review summarises the current knowledge on spondylolysis and spondylolisthesis and attempts to present a rational approach to the evaluation and management of this condition in children and adolescents.

Anterior shear strength of the porcine lumbar spine after laminectomy and partial facetectomy

Degenerative lumbar spinal stenosis is the most common reason for lumbar surgery in patients in the age of 65 years and older. The standard surgical management is decompression of the spinal canal by laminectomy and partial facetectomy. The effect of this procedure on the shear strength of the spine has not yet been investigated in vitro. In the present study we determined the ultimate shear force to failure, the displacement and the shear stiffness after performing a laminectomy and a partial facetectomy. Eight lumbar spines of domestic pigs (7 months old) were sectioned to obtain eight L2-L3 and eight L4-L5 motion segments. All segments were loaded with a compression force of 1,600 N. In half of the 16 motion segments a laminectomy and a 50% partial facetectomy were applied. The median ultimate shear force to failure with laminectomy and partial facetectomy was 1,645 N (range 1,066-1,985) which was significantly smaller (p = 0.012) than the ultimate shear force to failure of the control segments (median 2,113, range 1,338-2,659). The median shear stiffness was 197.4 N/mm (range 119.2-216.7) with laminectomy and partial facetectomy which was significantly (p = 0.036) smaller than the stiffness of the control specimens (median 216.5, 188.1-250.2). It was concluded that laminectomy and partial facetectomy resulted in 22% reduction in ultimate shear force to failure and 9% reduction in shear stiffness. Although relatively small, these effects may explain why patients have an increased risk of sustaining shear force related vertebral fractures after spinal decompression surgery.

Lumbar vertebral morphology and isthmic spondylolysis in a British medieval population

The British medieval population from Wharram Percy, England, has a greater prevalence of isthmic spondylolysis (11.9% of skeletons, 8.5% at the L5 level) than in modern populations (3%-6%). This may in part be due to differences in activity patterns between groups. However, Ward and Latimer (Spine 30 [2005] 1808-1814) proposed that the likelihood of developing and maintaining spondylolytic defects is also influenced by a lack of sufficient increase in mediolateral separation between articular processes in the lowest lumbar segments, given the human lumbar lordosis. Here, we demonstrate that spondylolytic individuals from Wharram Percy tend to have a less pronounced difference between mediolateral facet joint spacing of adjacent segments in the lowest lumbar region than do unaffected individuals, as seen in modern clinical and skeletal populations. These comparisons suggest that regardless of lifestyle, insufficient mediolateral increase in facet spacing predisposes people to spondylolytic defects, and so interfacet spacing patterns may have predictive utility in a clinical context. We also compare the Wharram Percy sample to a modern sample from the Hamann Todd collection with a typically modern prevalence rate. Data do not support the hypothesis that the Wharram Percy individuals had a less pronounced interfacet increase than the Hamann Todd, although they do have narrower lumbar facet spacing at the lowest three levels. Further investigation of anatomical variation underlying population-specific prevalence rates needs to be conducted.

Facet joint orientation difference between cephalad and caudad portions: a possible cause of degenerative spondylolisthesis

STUDY DESIGN

A case-control study. OBJECTIVE.: To measure the orientation of the facet joints at both cephalad and caudad portions and to compare them between patients with degenerative spondylolisthesis (DS) and patients with lumbar spinal stenosis (LSS, controls).

SUMMARY OF BACKGROUND DATA

Several radiologic studies have indicated a correlation between DS and an increased sagittal orientation of the facet joints. However, the orientation of the facet joints have only been measured on 1 axial cut of computed tomography scans and magnetic resonance imaging.

METHODS

Thirty-two patients with DS only at the L4-L5 level were assigned to group-1, and 28 patients with LSS without DS were assigned to group-2. Two computed tomography scans for the cephalad and caudad portions of the facet joint were made for L3-L4 and L4-L5 levels, respectively. Delta facet angle was defined as facet angle (cephalad)-facet angle (caudad).

RESULTS

Facet angles of the cephalad portion were more sagittally oriented (P < 0.001) than those of the caudad portion in group-1. The mean facet angle of the cephalad portion was 72 degrees and that of the caudad portion was 57 degrees at L4-L5. The mean facet angle of the cephalad portion at L4-L5 was greater (P = 0.001) in group-1 (72 degrees ) than in group-2 (62 degrees ). Delta facet angles were significantly greater in group-1 than in group-2. Mean delta facet angle was 15 degrees in group-1 and 2 degrees in group-2 at L4-L5 (P < 0.001), and 4 degrees and 0 degrees , respectively, at L3-L4 (P = 0.046).

CONCLUSION

In this study, we confirmed that the cephalad portion of the facet joints were more sagittally oriented and that the caudad portion of the facet joints were more coronally oriented in patients with DS. These findings were observed not only at L4-L5 but also at the uninvolved L3-L4 level in patients with DS at the L4-L5 level.

Cerebral palsy lifetime care - four musculoskeletal conditions

Cerebral palsy (CP) has always been considered a static condition in the neurological sense. Secondary and associated conditions that occur in the patient with CPcan progress over time and cause unwanted sequelae. This paper discusses four musculoskeletal conditions that present across the lifetime and can lead to progressive loss of function in the patient with CP. Patella alta can be particularly painful in the early adult years, limiting mobility particularly when associated with crouch gait. Adults with lower-extremity weight-bearing status having hip dysplasia, progressive over time, often develop pain and severe degenerative arthritis, with or without arthrodesis. Spondylolysis, particularly at the L5 S1 level, is fairly common in the ambulatory adult with diplegia and may, if not diagnosed early, progress to spondylolisthesis. Cervical stenosis appears to be more prevalent in adults with spastic quadriparesis and dystonia and is often associated with myelomalacia and/or radiculopathy. All four of these conditions may be lessened, or even prevented, with intervention and diagnosis in the younger years. Possible interventions and outcomes over time are discussed in the context of multidisciplinary team management of the individual with CP.

Degenerative spondylolisthesis of the cervical spine: analysis of 58 patients treated with anterior cervical decompression and fusion

BACKGROUND CONTEXT

Degenerative spondylolisthesis has been well described as a disorder of the lumbar spine. Few authors have suggested that a similar disorder occurs in the cervical spine. To our knowledge, the present study represents the largest series of patients with long-term follow-up who were managed surgically for the treatment of degenerative spondylolisthesis of the cervical spine.

PURPOSE

To describe the clinical presentation and radiographic findings associated with degenerative cervical spondylolisthesis, and to report the long-term results of surgically managed patients.

STUDY DESIGN

Analysis of 58 patients treated with anterior cervical decompression and fusion for degenerative spondylolisthesis of the cervical spine.

PATIENT SAMPLE

From 1974 to 2003, 58 patients were identified as having degenerative spondylolisthesis of the cervical spine occurring in the absence of trauma, systemic inflammatory arthropathy, or congenital abnormality. These patients were identified from a database of approximately 500 patients with degenerative cervical spine disorders treated by the senior one of us.

OUTCOME MEASURES

Patient outcomes were evaluated with regard to neurologic improvement (Nurick grade myelopathy) and osseous fusion.

METHODS

The records of 58 patients were reviewed. The average follow-up period was 6.9 years (range, 2-24 years). Seventy-two cervical levels demonstrated spondylolisthesis. In all cases, there was radiographic evidence of facet degeneration and subluxation. All patients were treated with anterior cervical decompression and arthrodesis with iliac crest structural graft. This most commonly involved corpectomy of the caudal vertebrae. Three patients required additional posterior facet fusion.

RESULTS

Fifty-eight patients demonstrated 72 levels of involvement. The C4-C5 level was most frequently involved (43%). Two radiographically distinct types of listhesis were observed based on the amount of disc degeneration and the degree of spondylosis at adjacent levels. The average neurologic improvement was 1.5 Nurick grades. The overall fusion rate was 92%. Three patients were treated with combined anterior-posterior arthrodesis. The prevalence of myelopathy and instability pattern was greater in the listheses occurring adjacent to spondylotic levels.

CONCLUSIONS

Degenerative spondylolisthesis is relatively common in the cervical spine. Common to all cases is facet arthropathy and neurologic compression. Anterior cervical decompression and arthrodesis appears to yield excellent union rates and neurological improvement in those patients having cervical degenerative spondylolisthesis and significant neurological sequelae who have failed nonoperative treatments.

Prevalence of vertebral pars defects (spondylolysis) in a population with osteogenesis imperfecta

STUDY DESIGN

We performed a retrospective study of spinal roentgenograms of a large cohort of patients suffering from osteogenesis imperfecta.

OBJECTIVE

To determine the prevalence of vertebral pars defects (spondylolysis) in patients with osteogenesis imperfecta.

SUMMARY OF BACKGROUND DATA

Patients suffering from osteogenesis imperfecta are known to be prone to pathologic fractures. Pathologic fractures due to microtraumas, repetitive activities, and posture acting together on a congenitally weakened pars interarticularis may lead to vertebral pars defects. The prevalence of vertebral pars defects in patients with osteogenesis imperfecta has never been studied before to our knowledge.

METHODS

We performed a retrospective study of posterior-anterior and lateral, standing, roentgenograms of the spine of patients with osteogenesis imperfecta for the occurrence of vertebral pars interarticularis defects.

RESULTS

The patients (5.3%) in our series showed vertebral pars defects, this is not significantly different from the prevalence of vertebral pars defects in the general population.

CONCLUSION

5.3% of the patients with osteogenesis imperfecta showed vertebral pars defects, this does not differ significantly from the occurrence in the general population.

Spine patient outcomes research trial: radiographic predictors of clinical outcomes after operative or nonoperative treatment of degenerative spondylolisthesis

STUDY DESIGN

Subgroup analyses according to treatment received.

OBJECTIVE

To evaluate whether baseline radiographic findings predicted outcomes in patients with degenerative spondylolisthesis.

SUMMARY OF BACKGROUND DATA

The spine patient outcomes research trial combined randomized and observational DS cohorts.

METHODS

The Meyerding listhesis grade was determined on the neutral radiograph (n = 222). Patients were classified as having low disc height if disc height was less than 5 mm. Flexion-extension radiographs (n = 185) were evaluated for mobility. Those with greater than 10 degrees rotation or 4 mm translation were considered hypermobile. Changes in outcome measures were compared between listhesis (grade 1 vs. grade 2), disc height (low vs. normal), and mobility (stable vs. hypermobile) groups using longitudinal regression models adjusted for potential confounders. Outcome measures included SF-36 bodily pain and physical function scales, oswestry disability index (ODI), stenosis bothersomeness index, and low back pain bothersomeness scale.

RESULTS

Overall, 86% had a grade 1 listhesis, 78% had normal disc height, and 73% were stable. Baseline symptom severity was similar between groups. Overall, surgery patients improved more than patients treated nonoperatively. At 1 year, outcomes were similar in surgery patients across listhesis, disc height, and mobility groups (ODI: grade 1 -23.7 vs. grade 2 -23.3, P = 0.90; normal disc height -23.5 vs. low disc height -21.9, P = 0.66; stable -21.6 vs. hypermobile -25.2, P = 0.30). Among those treated nonoperatively, grade 1 patients improved more than grade 2 patients (bodily pain + 13.1 vs. -4.9, P = 0.019; ODI -8.0 vs. + 4.8, P = 0.010 at 1 year), and hypermobile patients improved more than stable patients (ODI -15.2 vs. -6.6, P = 0.041; stenosis bothersomeness index -7.8 vs. -2.7, P = 0.002 at 1 year).

DISCUSSION

Regardless of listhesis grade, disc height or mobility, patients who had surgery improved more than those treated nonoperatively. These differences were due, in part, to differences in nonoperative outcomes, which were better in patients classified as grade 1 or hypermobile.

Facet joint osteoarthritis and low back pain in the community-based population

STUDY DESIGN

Cross-sectional study.

OBJECTIVE

To evaluate the association between lumbar spine facet joint osteoarthritis (FJ OA) identified by multidetector computed tomography (CT) and low back pain (LBP) in the community-based Framingham Heart Study.

SUMMARY OF BACKGROUND DATA

The association between lumbar FJ OA and LBP remains unclear.

METHODS

This study was an ancillary project to the Framingham Heart Study. A sample of 3529 participants of the Framingham Heart Study aged 40 to 80 underwent multidetector CT imaging to assess aortic calcification. One hundred eighty-eight individuals were consecutively enrolled in this ancillary study to assess radiographic features associated with LBP. LBP in the preceding 12 months was evaluated using a self-report questionnaire. FJ OA was evaluated on CT scans using a 4-grade scale. The association between FJ OA and LBP was examined used multiple logistic regression models, while adjusting for gender, age, and BMI.

RESULTS

CT imaging revealed a high prevalence of FJ OA (59.6% of males and 66.7% of females). Prevalence of FJ OA increases with age. By decade, FJ OA was present in 24.0% of <40-years-olds, 44.7% of 40- to 49-years-olds, 74.2% of 50- to 59-years-olds, 89.2% of 60- to 69-year-olds, and 69.2% of >70-years-olds. By spinal level the prevalence of FJ OA was: 15.1% at L2-L3, 30.6% at L3-L4, 45.1% at L4-L5, and 38.2% at L5-S1. In this community-based population, individuals with FJ OA at any spinal level showed no association with LBP.

CONCLUSION

There is a high prevalence of FJ OA in the community. Prevalence of FJ OA increases with age with the highest prevalence at the L4-L5 spinal level. At low spinal levels women have a higher prevalence of lumbar FJ OA than men. In the present study, we failed to find an association between FJ OA, identified by multidetector CT, at any spinal level and LBP in a community-based study population.

Degenerative lumbosacral spondylolisthesis: possible factors which predispose the fifth lumbar vertebra to slip

We have analysed a number of radiological measurements in an attempt to clarify the predisposing factors for degenerative spondylolisthesis of the lumbosacral junction. We identified 57 patients with a slip and a control group of 293 patients without any radiological abnormality apart from age-related changes. The relative thickness of the L5 transverse process, the sacral table angle and the height of the iliac crest were measured and evaluated. The difference in these measurements between men and women was analysed in the control group. We found that the transverse process of L5 was extremely slender, the sacral table more inclined, and the L5 vertebra was less deeply placed in the pelvis in patients with a slip compared with the control group. The differences in these three parameters were statistically significant. We believe that the L5 vertebra is predisposed to slip when these factors act together on a rigidly-stabilised sacrum. This occurs more commonly in women, probably as a result of constitutional differences in the development of the male and female spine.

Spondylolysis and spondylolisthesis in the athlete

Spondylolysis and spondylolisthesis are common diagnoses made in the athlete suffering from persistent back pain. Although the etiology of this continuum of conditions is uncertain, genetic predisposition and repetitive trauma have been strongly implicated. Sports in which participants are subjected to repetitive hyperextension across the lumbar spine pose a risk for such injuries. Football lineman, oarsmen, dancers, and gymnasts show high rates of these conditions. Treating the athlete with spondylolysis and/or spondylolisthesis can be a challenge. An inherent drive for return to competition, pressure from coaches and family, and obligations to the team can confound decision making on both the part of the patient and the treating physician. Although this motivation for prompt return to sports must certainly be considered, a safe return to competition is paramount.

Lumbar intervertebral instability: a review

Intervertebral instability of the lumbar spine is thought to be a possible pathomechanical mechanism underlying low back pain and sciatica and is often an important factor in determining surgical indication for spinal fusion and decompression. Instability of the lumbar spine, however, remains a controversial and poorly understood topic. At present, much controversy exists regarding the proper definition of the condition, the best diagnostic methods, and the most efficacious treatment approaches. Clinical presentation is not specific, and the relationship between radiologic evidence of instability and its symptoms is controversial. Because of its simplicity, low expense, and pervasive availability, functional flexion-extension radiography is the most thoroughly studied and the most widely used method in the imaging diagnosis of lumbar intervertebral instability. In this article, we provide an overview of the current concepts of vertebral instability, focusing on degenerative lumbar intervertebral instability, and review the different imaging modalities most indicated in diagnosing vertebral instability.

An oblique paraspinal approach for intracanalicular disc herniations of the upper lumbar spine: technical case report

OBJECTIVE

To present our experience of treating the central or paramedian disc herniations of the upper lumbar levels through a paraspinal approach.

CLINICAL PRESENTATION

We present four patients with intracanalicular disc herniations at the L1-L2 or L2-L3 level. All patients had unilateral or bilateral radicular leg pain and motor weakness.

TECHNIQUE

Considering the unique characteristics of the upper lumbar spine, we performed the oblique paraspinal approach to expose the central portion of disc and removed the herniated disc effectively. Postoperatively, their symptoms were improved. There was no instability during the follow-up period.

CONCLUSION

The oblique paraspinal approach for the treatment of central disc herniations at the upper lumbar levels is an effective nonfusion technique that preserves most of the facet joint and provides a wide surgical field.

Low-Grade Spondylolisthesis

Spondylolisthesis is an often painful condition affecting millions of people in North America with some ethnic variability. It is characterized by the displacement, usually anterior, of on vertebral body upon another. There are familial predispositions to having the lesion, and a family history of spondylolisthesis may raise one's clinical suspicion. Although the diagnosis is easily made on radiographic evaluation, the pathoetiology and appropriate treatment modality are not always as clear. In the absence of severe neurological symptoms or an unsafe component of instability, a trial of conservative management is reasonable and prudent. Nevertheless, surgical management is more efficacious for enduring symptomatic relief and restoration of physical function. Whereas assessment of postoperative radiographic results lends insight to surgical technique, the true barometer of treatment success is improvement in patient quality of life.

Spondylolisthesis caused by extreme pedicle elongation in osteogenesis imperfecta

Although osteogenesis imperfecta is a well-known skeletal disorder, reports of spondylolisthesis in osteogenesis imperfecta are rare. Only very few cases of spondylolisthesis caused by elongation of lumbar pedicles have been described in the literature. Here we report three patients suffering from osteogenesis imperfecta showing a severe form of hyperlordosis caused by lumbar pedicle elongation and consecutive spondylolisthesis. Radiographs in the course of childhood and adolescence show a rapid progression of pedicle elongation and hyperlordosis with increased mechanical loads. The treatment strategy consists of physiotherapy, medical treatment with bisphosphonates, and orthopedic surgery and is preferably conservative. In the three patients reported here, one patient was treated with laminectomy and postero-lateral fusion, whereas in the other two patients surgery is currently not considered as necessary.

Radiographic assessment of lumbar facet distance spacing and spondylolysis

STUDY DESIGN

Spondylolytic defects at L5 are influenced by insufficient differential spacing between the inferior articular facets of L4 and superior facets of S1. These structures then impinge on the intervening L5 pars interarticularis during hyperlordosis, contributing to fracture and resorption of the pars.

OBJECTIVES

Articular facet spacing was evaluated on clinical radiographs of normal and spondylolytic patients.

SUMMARY OF BACKGROUND DATA

Spondylolysis ranges from a hairline fracture through the pars to a complete pseudarthrotic defect. Insufficient increase in the distance between articular facets from L4-L5 to L5-S1 has been associated with chronic lytic defects in a skeletal sample.

METHODS

Anteroposterior radiographs of 39 patients with L5-S1 spondylolysis were compared with radiographs from 42 normal individuals. Differences in transverse distances between lumbar articular facets and pedicles were compared using 2-tailed t tests.

RESULTS

Patients with spondylolysis exhibited a smaller increase in interfacet distance from the L3-L4 facet joints to the L5-S1 joints than do normal patients, even relative to vertebral size.

CONCLUSIONS

Spondylolytic fractures at L5 are influenced by an inadequate increase in interfacet distances between adjacent vertebrae. Individuals lacking sufficient increase in lower lumbar transverse interfacet dimensions are at greater risk of developing and maintaining spondylolytic defects.

Degenerative lumbar spondylolisthesis: an epidemiological perspective: the Copenhagen Osteoarthritis Study

STUDY DESIGN

A cross-sectional epidemiological survey of 4151 participants of the Copenhagen Osteoarthritis Study.

OBJECTIVE

To identify prevalences and individual risk factors for degenerative lumbar spondylolisthesis.

SUMMARY OF BACKGROUND DATA

The Copenhagen Osteoarthritis Study has registered health parameters since 1976. In 1993, standardized, lateral radiographs of the lumbar spine were recorded. There were 1533 men and 2618 women.

METHODS

Statistical correlations were made between degenerative spondylolisthesis, and physical, occupational, and general epidemiological data.

RESULTS

A total of 254 cases of lumbar slip were found (males 2.7%, females 8.4%). In females, no significant relationship between age at menopause or childbirths and the presence of degenerative spondylolisthesis were found. In women, relationships between body mass index (BMI) in 1976 and L4 olisthesis (P = 0.001), and between BMI in 1993 and both L4 and L5 olisthesis were found (L4: P = 0.003; L5: P = 0.006). Lumbar lordosis was associated with degenerative spondylolisthesis in women. Occupational exposures to daily lifting or smoking were not associated with degenerative spondylolisthesis. Degenerative spondylolisthesis was associated with increased age in both sexes (L4: P < 0.001; L5: P < 0.001).

CONCLUSIONS

BMI longitudinally and at index evaluations, age, and angle of lordosis were significantly associated with degenerative spondylolisthesis in women. In men, no individual risk factors for degenerative spondylolisthesis were found, save increased age.

Treatment of symptomatic spondyloptosis in an adult previously treated with in situ fusion and instrumentation by L5 vertebrectomy and L4-S1 instrumented reduction

BACKGROUND CONTEXT

One traditional treatment for spondylolisthesis is fusion. However, for high-grade spondylolisthesis and spondyloptosis, posterior fusion has had high rates of nonunion, progression, and persistent physical deformity. Thus, some surgeons have recommended reduction and instrumentation. One such technique (Gaines procedure) entails a two-stage procedure: L5 vertebrectomy anteriorly, followed by resection of the L5 posterior elements and instrumented reduction of L4 onto S1. However, to our knowledge, there is no report of reversing the fusion and deformity reduction in a symptomatic patient with previous solid fusion of the spondyloptosis at L5-S1.

PURPOSE

To present the first reported revision via the Gaines procedure for failed fusion secondary to spondyloptosis.

STUDY DESIGN

Patient report.

METHODS

A 24-year-old woman, who had undergone multiple procedures for L5-S1 spondylolisthesis and a final fusion and instrumentation attempt, presented with continued urinary retention, leg and back pain, and inability to stand. She subsequently underwent posterior hardware removal, followed by anterior L5 vertebral body resection. In the second stage, she had posterior osteotomy of the previous L5-S1 fusion, resection of the posterior elements of L5, and reduction and instrumentation of L4 to S1.

RESULTS

At the 2-year follow-up, she had full resolution of symptoms, full return of motor strength, and resolution of urinary retention.

CONCLUSIONS

The Gaines procedure has been performed successfully in patients without previous fusions at the level of spondylolisthesis or spondyloptosis. Patients for whom the traditional posterior fusion fails still may be candidates for this procedure, albeit at increased risk of neurologic injury.

Posterolateral fusion using laminectomy bone chips in the treatment of lumbar spondylolisthesis

We retrospectively reviewed the outcome of posterolateral fusion (PLF) in 136 patients with lumbar spondylolisthesis (LS), who had undergone posterior decompression laminectomy with foraminotomy and PLF using laminectomy bone chips as bone graft, with reduction of the slipped vertebra with transpedicle screws, between 1993 and 2003. Diagnosis of LS was confirmed by plain lumbar radiography, with computed tomography (CT) scan or magnetic resonance imaging (MRI) studies performed to confirm an associated condition, such as ruptured disc and spinal stenosis. The outcome of spinal fusion was good with 129 (94.85%) patients attaining solid fusion, while failed fusion was noted in seven (5.15%) patients. None of our patients complained of excessive postoperative wound pain. Additionally, no complications, such as wound infection, were encountered. Proper decortication of the posterior paravertebral gutters with an osteotome and removal of all soft tissues from the laminectomy bone chips are significant factors contributing to the successful outcome of the laminectomy bone chips in PLF. The fusion rate obtained with this type of autogenous bone graft is comparable to that of the iliac bone crest autogenous graft; hence, it is a good substitute for the iliac crest bone autogenous graft in performing PLF in treating lumbar spondylolisthesis.

[Surgical treatment of spondylolisthesis in Gabon]

PURPOSE

Spondylolisthesis is a spinal disease revealed by lombalgia and/or lombosciatalgia, which may persist under medical treatment and physiotherapy. Indications for surgery are impairing symptoms and emergency conditions. We report outcome in 21 patients (14 women, 7 men, aged from 30 to 60 years old) who underwent surgery for isthmic (n = 10) and degenerative (n = 11) spondylolisthesis. Radiographic staging was: I in seven patients, II in ten, and III in four.

METHOD

Many techniques were used: simple laminectomy (n = 4), Gill's operation (n = 4), Lapras' technique (n = 4), and Roy-Camille instrumentation (n = 9).

RESULTS

Immediate and long-term postoperative follow-up of sixteen patients confirm good results: excellent outcome in eleven patients, good in four, and fair in one.

CONCLUSION

Considering social and economic factors, we prefer Lapras' technique which provides very satisfactory results.

Spondylolysis and spondylolisthesis in children and adolescents: I. Diagnosis, natural history, and nonsurgical management

Spondylolysis and spondylolisthesis are often diagnosed in children presenting with low back pain. Spondylolysis refers to a defect of the vertebral pars interarticularis. Spondylolisthesis is the forward translation of one vertebral segment over the one beneath it. Isthmic spondylolysis, isthmic spondylolisthesis, and stress reactions involving the pars interarticularis are the most common forms seen in children. Typical presentation is characterized by a history of activity-related low back pain and the presence of painful spinal mobility and hamstring tightness without radiculopathy. Plain radiography, computed tomography, and single-photon emission computed tomography are useful for establishing the diagnosis. Symptomatic stress reactions of the pars interarticularis or adjacent vertebral structures are best treated with immobilization of the spine and activity restriction. Spondylolysis often responds to brief periods of activity restriction, immobilization, and physiotherapy. Low-grade spondylolisthesis (< or =50% translation) is treated similarly. The less common dysplastic spondylolisthesis with intact posterior elements requires greater caution. Symptomatic high-grade spondylolisthesis (>50% translation) responds much less reliably to nonsurgical treatment. The growing child may need to be followed clinically and radiographically through skeletal maturity. When pain persists despite nonsurgical interventions, when progressive vertebral displacement increases, or in the presence of progressive neurologic deficits, surgical intervention is appropriate.

Dynamic degenerative lumbar spondylolisthesis: diagnosis with axial loaded magnetic resonance imaging

STUDY DESIGN

Retrospective review of case notes and imaging.

OBJECTIVE

To show the advantage of axial loaded magnetic resonance imaging (MRI) for identification of dynamic degenerative spondylolisthesis as a suspected cause of spinal claudication.

SUMMARY OF BACKGROUND DATA

Degenerative spondylolisthesis typically occurs at L4/L5 and is usually evident on plain radiography. However, dynamic degenerative spondylolisthesis may become evident on erect radiographs when not shown on supine radiographs or MRI.

METHODS

The case notes and imaging (radiography, conventional MRI, and axial loaded MRI) in 2 patients with symptoms of spinal claudication were reviewed.

RESULTS

A 44-year-old female presented with a 3-year history of intermittent low back pain and right leg numbness after a fall. A 52-year-old female presented with a 4-year history of low back pain, bilateral leg weakness, and right leg numbness. In both cases, conventional MRI studies showed mild-to-moderate degenerative disc disease only with no evidence of abnormal spinal alignment or nerve root compression. Axial loaded MRI clearly showed the development of a degenerative spondylolisthesis with central canal stenosis and facet ganglion formation in 1 case.

CONCLUSIONS

Axial loaded MRI identified occult dynamic degenerative spondylolisthesis, which correlated with the clinical picture but was not shown on initial conventional MRI or plain radiography.

Spinal tuberculosis with concomitant spondylolisthesis: coexisting entities or ‘cause and effect’?

STUDY DESIGN

Report of three unusual cases of coexisting spondylolisthesis and tuberculosis in the same patient.

OBJECTIVES

To document the rare occurrence and attempt to postulate the probable reasons for such an association.

SETTING

Tertiary care teaching hospital in a developing country.

METHODS

This communication reports the outcome of three cases where there was spondylolisthesis and spinal tuberculosis in the same patient. The probable reason for such an occurrence is discussed along with a literature review relevant to this topic.

RESULTS

The cases responded favorably to conservative treatment with multidrug antitubercular chemotherapy and spinal braces.

CONCLUSIONS

Association of spondylolisthesis and spinal tuberculosis is extremely rare. If the tubercular process is fulminant, spondylolisthesis secondary to destruction of posterior elements by the infective process can occur. Gross destruction of anterior elements secondary to tuberculosis in some patients may place excessive stresses on the posterior elements and may precipitate a spondylolisthesis even if there was no active infection in the posterior elements. However, there remains a distinct possibility that pars defect may have existed prior to infective pathology.

Operative Therapie bei Spondylolyse und Spondylolisthese

The therapy for spondylolysis and spondylolisthesis is challenging in view of the large variety of treatment options. A general, standardized therapeutic concept has still not been established. Adequate therapy depends on different parameters and personal experience. Beside direct repair surgery of spondylolysis and low grade spondylolisthesis, dorsal, ventral and combined dorsoventral surgery, with or without instrumentation, are indicated depending on patients age and severity of the slip. Complications such as pseudarthrosis and progression of the slip develop in a given percentage of cases, but these are not significantly correlated with clinical symptoms. Decompression is necessary in high grade slippage with neurologic impairment, especially paresis. Reposition is associated with a higher risk of neurologic complications. Fusion in situ without instrumentation, even in moderate and severe spondylolisthesis, shows good clinical results with high fusion rates and without the increased risk of progression and pseudarthrosis. In many cases, it is an effective, safe and economic therapeutic option.

Human evolution and the development of spondylolysis

STUDY DESIGN

We propose that chronic spondylolytic defects at L5 are influenced by insufficient differential mediolateral distances between inferior articular facets of L4 and the superior facets of S1, which results in these structures impinging on adjacent sides of the par interarticularis during hyperlordosis. Individuals with adequate increase in interfacet distances from L4 through S1 are less likely to develop or maintain defects.

OBJECTIVES

We test the above hypothesis by comparing the transverse interfacet dimensions throughout the lumbar columns of normal and spondylolytic individuals.

SUMMARY OF BACKGROUND DATA

Spondylolysis is a common condition, yet its etiology is poorly understood. It is generally considered to be the result of a vaguely defined fatigue fracture through the pars interarticularis. The cause(s) of spondylolysis, however, have not been clearly identified.

METHODS

Lumbar vertebrae from the Hamann-Todd osteological collection at the Cleveland Museum of Natural History were examined. Thirty individuals with bilateral spondylolysis at L5 were compared with 30 age- and sex-matched controls. Differences in transverse distances between articular facets and in transverse breadths of vertebral bodies were compared using two-tailed t tests.

RESULTS

Results show that normal individuals have a significantly greater increase in interfacet dimensions progressing down the spine from L4 to S1 than do those with spondylolysis. These differences are not the result of normal individuals having increasingly large vertebrae, as results are significant even when standardized for vertebral body breadth. Vertebral body size itself does not differ systematically between groups.

CONCLUSIONS

Spondylolysis is the direct result of contact pressures on both sides of the pars interarticularis resulting from inadequate separation between the inferior articular processes of L4 and the superior articular facets of S1. Individuals lacking sufficient increase in transverse interfacet dimensions in their lumbar columns are at greater risk of developing and maintaining spondylolytic defects.

New concepts on the pathogenesis and classification of spondylolisthesis

STUDY DESIGN

A review of the literature in the English language pertaining to the pathogenesis and classification of spondylolisthesis.

OBJECTIVE

To review the morphology and biomechanics of the lumbosacral junction as it relates to spondylolisthesis. To present contemporary theories of the development and progression of spondylolisthesis and an etiology-based classification system.

SUMMARY OF BACKGROUND DATA

The proper treatment of spondylolisthesis is dependent on recognizing the type of slip and its natural history. Although a number of clinical and radiographic features have been identified as risk factors, their role as primary causative factors or secondary adaptive changes is not clear. In particular, confusion persists over the classification of slips with "isthmic defects." The early identification of spondylolisthesis that will progress to a high grade without intervention remains elusive.

METHODS

A review of English language literature regarding the pathogenesis and classification of spondylolisthesis. RESULTS.: Current literature suggests that spinopelvic parameters, in addition to the morphology and biomechanics of the lumbosacral junction, play a causative role in the development of spondylolisthesis. Progression of developmental slips may be due to growth deficiencies of the anterosuperior sacrum, analogous to Blount's disease at the knee. The Marchetti-Bartolozzi classification system emphasizes the distinction between developmental dysplastic slips and acquired laminar stress fractures, both of which may have isthmic defects. These two types of spondylolisthesis have significantly different natural histories, suggesting the need for different treatment strategies. The Marchetti-Bartolozzi system also allows for the classification of postsurgical, pathologic, and degenerative forms of spondylolisthesis.

CONCLUSIONS

The morphology of the lumbosacral junction resists high shear and compressive forces. The loss of the posterior restraint through an incompetent bony hook may result in the forward displacement of one vertebra on the subjacent vertebra. The spinopelvic parameters, such as pelvic incidence, may be greater determinants of development and progression than previously appreciated. The Marchetti-Bartolozzi classification system is applicable to all forms of lumbar spondylolisthesis,and seems to be clinically relevant in terms of treatment decisions. Their system emphasizes the distinction between developmental spondylolisthesis with lysis and acquired spondylitic spondylolisthesis, which have been included together in previous classification systems and caused confusion over natural history and treatment. Developmental slips have a greater propensity toward progression, which may be secondary to growth deficiencies of the upper sacrum. Further study is required to confirm these observations.

Adult low-grade acquired spondylolytic spondylolisthesis: evaluation and management

STUDY DESIGN

Literature review.

OBJECTIVE

To discuss the presentation and evaluation of adult patients with acquired spondylolytic spondylolisthesis of low-grade severity and to review surgical treatment options.

SUMMARY OF BACKGROUND DATA

Low-grade adult acquired spondylolytic spondylolisthesis is one of the most common forms of spondylolisthesis.

METHODS

Literature review.

RESULTS

Adults with symptomatic low-grade spondylolytic spondylolisthesis are treated predominantly nonoperatively, with activity modification, physiotherapy, nonsteroidal anti-inflammatory agents, and local injections. Surgical treatment is reserved for individuals with intractable back pain and/or radicular symptoms. A number of surgical options exist, including direct pars repair, and fusion with or without decompression. Fusion can be achieved by providing anterior column support alone, posterior support alone, or a combined circumferential approach; the optimal method by which fusion should be achieved has not been established.

CONCLUSIONS

The management of low-grade acquired spondylolytic spondylolisthesis requires a thoughtful and individualized approach, recognizing the frequently benign natural history of the deformity and the potentially good clinical outcomes from surgery in those select patients with intolerable back and leg pain. While fusion is the mainstay of surgical management, a prospective randomized study would be extremely useful to delineate the optimal fusion technique.

Expression of estrogen receptor of the facet joints in degenerative spondylolisthesis

STUDY DESIGN

Immunohistochemical study was done by harvesting articular cartilage of the facet joints during the decompressive surgery for spinal stenosis.

OBJECTIVES

To observe the expression of estrogen receptor on the articular cartilage of the facet joints in degenerative spondylolisthesis (DS) SUMMARY OF BACKGROUND DATA: Few attempts have been made to evaluate the effect of sex-hormone, although DS is more common in females than in males.

METHODS

After harvesting the articular cartilage of the facet joints in 17 DS and in 15 spinal stenosis (SS) patients, the expression of estrogen receptor and the severity of facet arthritis were observed by H-E and immunohistochemical staining, respectively. Measurements of both staining were made by using a semiquantitative analysis.

RESULTS

The significantly increased expression of estrogen receptor correlated with the severity of facet arthritis (r = 0.78, P < 0.05). There was a significantly increased expression of estrogen receptor of the facet joint in DS compared with SS (P < 0.01). The histologic-histochemical grading of cartilage lesion in DS was 12.4 (SEM, 0.6), which was significantly higher than in SS (P < 0.05).

CONCLUSIONS

These findings suggest that the higher expression of estrogen receptor might aggravate degenerative change of the facet articular cartilage and might also be considered one of the causative factors for DS in postmenopausal women.

Degenerative disease in lumbar spine of military parachuting instructors

Parachuting, be it static line or skydiving, places enormous stresses on the human spine. It is, therefore, important to determine the prevalence and severity of degenerative changes in the lumbar spine of subjects who practice this sport activity. Seventy four parachuting instructors, mean age 33 years and with an average of 410 static line and skydiving jumps, were included in the study. Past radiographs were examined and compared to current anterolateral and lateral views of the lumbar spine, in order to determine the prevalence of degenerative changes and document possible progression. Doubtful radiographic changes in the lumbar spine were identified in 47.4 percent of the parachuting instructors, mild degeneration in 9.6 percent, moderate degenerative disease in 10.9 percent and severe radiographic changes in 5.5 percent. Schmorll nodes were found in 8.1 percent of the subjects. Traction spurs--osteophytes were identified in 6.8 percent. The degenerative changes correlated with age and the number of jumps. Spondylolysis of L5-S1 and L3-L4 segments were observed in 12.2 and 1.4 percent respectively. Progressive spondylolisthesis was found in 2 subjects. No correlation was found between the severity of radiographic changes and either the prevalence and the severity of low back pain. The present findings provide a rational for considering repeated sheer stress as an etiology of degenerative changes in the spinal cord, and as a possible contributing factor to the pathogenesis of spondylolysis. Further study has to be done comparing parachuting instructors to a non-parachuting group, or equivalent physically active individuals, in order to assess the effect of sport-background on the development of degenerative changes.

Spondylolisthesis in pre-school children

Although the natural history of spondylolisthesis is poorly described, we know that it is rare to see the condition in children before they are 5 or 6 years old. Treatment in these patients may be confusing because there is very little literature on the subject, and most papers are case reports. We present a series of eight pre-school patients (mean age 3.5 years; range 9 months to 5 years) with spondylolisthesis with an average follow up of 11.5 years (range 9-14 years). In our experience, general guidelines for treatment as given by Wiltse and Jackson are useful in patients younger than 5 years. Nowadays we have to keep strict control of these patients due to their important capacity for growth that increases the possibility of further slippage.

Treatment of L5-S1 Spondyloptosis With Single-Stage Surgery Through the Posterior Approach-Case Report-

A 21-year-old male patient with L5-S1 spondyloptosis was treated by total L-5 laminectomy with foraminotomy and posterior fusion through the posterior approach. His complaints of severe low back pain and limited spine mobility were resolved. No new deficits occurred. The surgical management of spondyloptosis includes one-, two-, or three-stage operations with posterior, anterior, or combined approaches. Careful posterior decompression and posterior fusion without reduction may be adequate for the treatment of L5-S1 spondyloptosis.

Stress fractures of the lumbar pars interarticularis in athletes: a review based on long-term results of 18 professional cricketers

The physical demand of the modern game of cricket on the fast bowler is known to cause stress fractures of the lumbar spine. Between 1983 and 2001, we diagnosed pars interarticularis defects in 18 professional cricketers contracted to a single English County Cricket Club. Eight of these players were treated conservatively, with rest, supervised rehabilitation, bowling action analysis and re-education where necessary. The remaining 10 were treated operatively, 9 by Buck's repair of the spondylolytic lesion. All 18 players returned to professional sport.We recommend treatment of this select group of sportsmen in a unit consisting of a specialist physiotherapist, a bowling coach and a spinal surgeon. Should conservative measures fail, we recommend Buck's repair as the operation of choice.

Intraoperative biomechanical assessment of lumbar spinal instability: validation of radiographic parameters indicating anterior column support in lumbar spinal fusion

STUDY DESIGN

Lumbar spinal instability was evaluated using radiographic parameters and intraoperative biomechanical measurement.

OBJECTIVES

To validate a conventional radiographic assessment using an intraoperative biomechanical measurement and to determine the radiographic parameters indicating anterior column support in lumbar spinal fusion.

BACKGROUND

Posterior lumbar interbody fusion is gaining acceptance in the treatment of degenerative spondylolisthesis, whereas posterolateral fusion alone may result in good clinical outcomes. A quantitative biomechanical assessment of spinal instability is essential to determine the optimal method of spinal arthrodesis.

MATERIALS AND METHODS

Nineteen cases with symptomatic degenerative spondylolisthesis were included in this study. All were candidates for pedicle-screw instrumented lumbar arthrodesis. A total of five L3-L4 segments and seventeen L4-L5 segments were investigated. Radiographic assessment included disc angle, range of motion (ROM), percent of slip, and percent of posterior disc height. Distraction stiffness of the operative segment was measured intraoperatively using a strain-gauged spreader.

RESULTS

Disc angle in flexion and ROM were highly correlated to distraction stiffness. Severity of slip, disc space narrowing, and facet tropism did not influence the distraction stiffness. The cases with segmental kyphosis in flexion had significantly lower distraction stiffness than those showing segmental lordosis in flexion.

CONCLUSIONS

Disc angle in flexion and ROM were the most prognostic parameters of lumbar distraction instability. Although the option of spinal arthrodesis method should be determined based on both clinical manifestation and imaging studies, the current study demonstrated that providing of anterior column support is biomechanically reasonable for degenerative spondylolisthesis with segmental kyphosis in flexion.

The natural history of spondylolysis and spondylolisthesis: 45-year follow-up evaluation

STUDY DESIGN

A prospective study of spondylolysis and spondylolisthesis was initiated in 1955 with a radiographic and clinical study of 500 first-grade children.

OBJECTIVE

To determine the natural history of spondylolysis and spondylolisthesis.

SUMMARY OF BACKGROUND DATA

Most studies on the natural history of spondylolysis and spondylolisthesis are based on patient populations presenting with pain. Critical to any natural history investigation is the study of a population of affected individuals, whether symptomatic or not, from onset of the condition through their lives.

METHODS

By study of a population from the age of 6 years to adulthood, 30 individuals were identified to have pars lesions. Data collection at a 45-year follow-up assessment included magnetic resonance imaging, a back pain questionnaire, and the SF-36 Survey.

RESULTS

No subject with a pars defect was lost to follow-up evaluation once a lesion was identified. Subjects with unilateral defects never experienced slippage over the course of the study. Progression of spondylolisthesis slowed with each decade. There was no association of slip progression and low back pain. There was no statistically significant difference between the study population SF-36 scores and those of the general population the same age.

CONCLUSIONS

This report is the only prospective study to document the natural history of spondylolysis and spondylolisthesis from onset through more than 45 years of life in a population unselected for pain. Subjects with pars defects follow a clinical course similar to that of the general population. There appears to be a marked slowing of slip progression with each decade, and no subject has reached a 40% slip.

Magnetic resonance imaging of sports injuries of the spine

Spinal injuries are relatively frequent events in professional athletes. Greater popularity of recreational athletic activities has increased the occurrence of sports-related spinal injuries in the general population. The demand of high-intensity sports places a constant load on the vertebral column. Several studies have demonstrated higher prevalence of spinal abnormalities in athletes than nonathletes. Direct correlation of the number and extent of injuries with the length in years of sports activity has been established. Diagnostic imaging, particularly magnetic resonance imaging (MRI), plays a crucial role in evaluating and detecting sports-related spinal injuries. Subtle bone marrow, soft-tissue, and spinal cord abnormalities, which may not be apparent on other imaging modalities, can be readily detected on MRI. Early detection often leads to prompt accurate diagnosis and expeditious management, in many cases avoiding unnecessary procedures. This article reviews the technical aspects of MRI for evaluation of the spine and the role of MRI in the assessment of sports-related spinal injuries.

The lateral buttress: an anatomic feature of the lumbar pars interarticularis

STUDY DESIGN

A morphometric study of the lateral buttress region of the lumbar pars interarticularis from L1-L5 on 10 dried lumbar spines was performed.

OBJECTIVE

To qualitatively describe and quantitatively evaluate this portion of the pars and to discuss its clinical and surgical relevance.

BACKGROUND

The "lateral buttress" is a bony bridge connecting the superolateral edge of the inferior facet to the pedicle/transverse process junction, offering structural support to the pars interarticularis at upper lumbar levels. To date, no anatomic study has evaluated this structure.

METHODS

Direct measurements using vernier calipers were taken at each level, L1-L5, from 10 dried lumbar spines. Surface area of the buttress was calculated and compared statistically for differences between each level, as well as normalized relative to L3.

RESULTS

The surface areas of the buttresses at L1-L3 were similar, measuring near 80 +/- 10 mm2. At L4, it measured 50 +/- 10 mm2. And at L5, it measured 15 +/- 5 mm2. These differences were statistically significant. Normalized data showed the buttress at L4 to be 40% smaller and at L5 to be 80% smaller than at upper levels.

CONCLUSIONS

This study provides descriptive and anatomic data regarding the lateral buttress portion of lumbar pars interarticularis. The broad buttress of the upper lumbar levels offers support to the pars but can confuse anatomic guidelines for pedicle screw placement and paraspinal approaches. The narrow buttress of lower lumbar levels makes pedicle screw placement and the paraspinal approach easier, but it lessens support to the pars, making spondylolysis and iatrogenic instability more likely.

Surgical management of cervical and lumbosacral radiculopathies: indications and outcomes

The most common indication for the surgical management of compressive cervical and lumbar radiculopathies is a herniated disc in a patient who has not improved with conservative management. Even though a herniated disk is a common condition, it is paramount that the examining physician considers an extensive differential diagnosis when evaluating radiculopathies, especially in patients with a history of cancer, multiple medical illnesses, secondary gain, or advanced age. This consideration has become even more important as imaging studies have improved, because previously undetected degenerative changes are now clearly visualized on MRI and CT scans. These improved studies, however, do not replace a thorough history and physical examination, because a patient's signs and symptoms may not correlate with the radiographic findings. The authors have presented a series of surgical techniques used to manage cervical and lumbar discectomies to the most recent "minimally invasive" percutaneous techniques. Much debate and controversy surround these more recent techniques. There is no controversy, however, in stating that achieving good outcomes, regardless of technique, is predicated on proper patient selection. Because patient selection is the most important predictor of outcome and because serious complications have been reported with "minimally invasive" percutaneous procedures, the authors continue to advocate the proven traditional surgical approaches until prospective, randomized studies demonstrate a clear benefit to using alternative techniques.

Lumbar spinal stenosis, cauda equina syndrome, and multiple lumbosacral radiculopathies

Narrowing of the vertebral canal, the lateral recess, or the neural foramina causes lumbar spinal stenosis. Stenosis results from degenerative changes that usually are superimposed on a congenitally narrowed spinal canal and can result in significant pain and disability, especially in the elderly. Signs and symptoms are related to the compression of neural and vascular elements from the limited canal space. The article reviews the anatomy and pathophysiology, clinical syndrome, diagnostic workup, and natural history of lumbar spinal stenosis to aid in proper diagnosis and treatment.