Family study of spondylolysis and spondylolisthesis

Seventy index patients and 222 first-degree relatives with spondylolysis or spondylolisthesis have been studied by means of interview and clinical and radiological examinations. The index patients had an average age of 18 years, and included 43 females and 27 males. Following Wiltse's classification, 18 patients had dysplastic lesions and 52 had isthmic defects. The first-degree relatives included 99 parents and 125 siblings and children of the index patients. Both isthmic and dysplastic defects occurred in most families, regardless of the classification of the index patient. Isthmic defects were consistently more frequent than dysplastic defects. Spina bifida occulta occurred at the lumbosacral area in 61% of the index patients; in the first-degree relatives, spina bifida occulta was most common among the siblings and children of index patients, and occurred more often in relatives of index patients with dysplastic lesions than in those with isthmic lesions.     

峡部植骨治疗腰椎椎弓峡部裂和腰椎滑脱

介绍一种治疗腰椎椎弓峡部裂合并轻度腰椎滑脱的手术方法。手术通过在峡部及关节突关节处植骨使快部缺损得到直接修复并使腰椎获得稳定。共治疗46例98处病变，随访7个月～4年2个月，平均13个月。94处获得骨性融合，占95．9％。计优28例，良15例，可3例。作者认为峡部植骨修复融合术与其他融合术式相比，对腰椎的正常生理活动范围干扰及手术创伤均较小，操作技术亦相对简单，对于青少年及多节段推弓峡部裂患者尤为适合，但要求植骨确实可靠，以防骨不连发生。     

Long-term clinical and radiological follow-up of spondylolysis and spondylolisthesis

A clinical and radiological follow-up study with at least 20 years of observation was made of 255 spondylolysis and spondylolisthesis patients for examination of the clinical course and its possible correlation to radiographic findings. The progression of slipping was small and not correlated to age at diagnosis and initial degree of spondylolisthesis. Disc height reduction at the spondylolytic level occurred at an earlier age and was more severe than in a normal control group. Symptoms were correlated to radiographic pathology. Risk factors for low-back symptoms were greater than 25% slipping, low lumbar index in L5 spondylolysis, spondylolysis at the L4 level, and early disc degeneration.     

Surgical therapy for spondylolysis and spondylolisthesis

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.     

Isthmic spondylolisthesis and spondylolysis

Isthmic spondylolisthesis, or spondylolisthesis due to a lesion of the pars interarticularis, is a common source of pain and disability in both the pediatric and adult population. This review examines the current diagnostic and treatment options for patients with this condition. It also reviews the results of the various interventions to facilitate the surgeon in choosing the appropriate treatment option for any given patient.     

Mechanical factors in spondylolisthesis and spondylolysis.

Anterior displacement in spondylolisthesis is a slow process. The forces contributing to anterior shear arise from the vertical load on the spine above the lesion, from activity in the muscles of the spine and trunk, and from the effects of movements. The shear is normally resisted by the annulus fibrosus, compression of the facets at the apophyseal joints, and by tension in the anterolateral layers of cortical bone in the pars interarticularis. The anterior shear-strength of the disk is not known though Cyron and Hutton have shown that it is a major contributor to the total stiffness; in the early stages of spondylolysis it provides the only resistance. The capacity of the pars for resisting tensile forces anteriorly has been studied in tests of single vertebrae in which posterior forces were applied to the inferior articular processes. Forces at failure at L4 and L5 have been reported at up to 2500 N by Cyron et al. and up to 5800 N by Lamy et al. with means of 1800 N and 3200 N respectively. The mean posterior displacement of the inferior facets reported by Cyron et al. was 6.5 mm at failure. Too little is known of the mechanical factors in the etiology of spondylolysis for a definition of the postures and movements of the body which put the lumbar neural arch at greatest risk. While a combination of fatigue-failure and high strain-rate of forces induced in extended postures seems likely, further investigations are needed to elucidate the pathogenesis in many cases.     

Treatment of spondylolisthesis and spondylolysis in children.

There are 2 fairly common types of spondylolisthesis in children - dysplastic and isthmic. The dysplastic type is secondary to congenital defects at the lumbosacral joint. The isthmic is usually due to a fatigue fracture of the pars interarticularis but there is also an hereditary element in this type. Most children with spondylolisthesis never develop significant symptoms and even of those who do, the vast majority can be treated without surgery. If symptoms persist or if further olisthesis is occurring, a one-level spinal fusion done through a paraspinal approach is recommended. It is most important not to allow olisthesis to develop to the point that the child shows the cosmetically undesirable stigmata characteristic of the condition. Solid fusion can be obtained in every case and will stop further slip.     

The mechanical etiology of spondylolysis and spondylolisthesis.

There are 3 mechanisms that may result in failure of the neural arch with or without displacement of the vertebral body of the pathological vertebral: flexion overload, unbalanced shear forces and forced rotation. It is understood that all types of overload may be applied simultaneously and in various combinations. Of all the forces acting on the lumbar spine torsional violence is the most disruptive of the neural arch. Besides causing olisthesis, it is also capable of producing lysis of the pars especially if the dorsal spine has the added restraint of high tensile stresses in the posterior ligamentous system. Under normal conditions, the L5-S1 intervertebral joint is subject to the highest forces and it therefore receives the first damage. However, in the presence of antiverse process, damaging stress occurs in the next higher joint. While the antitorsional large transverse process may protect the L5-S1 joint from torsion, it may not protect the L5 vertebra from excessive flexional strains that may fracture the pars. Though lysis may occur in both instances, paradoxically spondylolysis and spondylolisthesis are mutually exclusive conditions. It has long been thought that shear force imbalance was the causative agent in olisthesis. This mechanism remains unconvincing except possibly in instances where there is a pathological condition affecting the skeletal tissue.     

Cervical spondylolysis with spondylolisthesis. Case report.

The authors describe as case in which cervical spondylolysis was found at multiple levels with spondylolisthesis and associated neurological deficits. Radiographic findings with the absence of history of trauma suggest a congenital etiology.     

Conservative management of spondylolysis and spondylolisthesis

Spondylolysis and spondylolisthesis are pathologic defects that can cause low back pain. While they are often asymptomatic, a thorough radiologic evaluation and correlation with the clinical presentation is necessary to guide appropriate intervention. The physician׳s role in these cases is a timely diagnosis, treatment, and follow-up given the risk of progression that accompanies this type of pathology. Conservative management is currently the first-line for many instances of mild-to-moderate spondylolysis and spondylolisthesis, with the goal of pain relief and return of function.     

Natural history of spondylolysis and spondylolisthesis

Spondylolysis refers to a defect in the pars interarticularis of the vertebrae; spondyolisthesis, or a slippage of one vertebral body on another, can result from spondylolysis or other conditions. Both conditions may be a cause of low back pain, but are also commonly seen as incidental findings in asymptomatic patients. The natural history of these conditions is important to understand in order to counsel patients and determine a course of action when either diagnosis is made, and varies based upon etiology as well as patient characteristics.     

腰椎峡部裂和滑脱症外科治疗的探讨

报告自１９６５～１９９１年９２例有症状的腰椎峡部裂和滑脱的外科治疗。１９６５～１９７１年采用经腹椎体间前植骨融合２２例； １９７１～１９７８年采取腹膜外入路椎间植骨融合或Ｒｏｍｂｏｌｄ法后外侧融合术２０例；１９８７～１９９１年峡部裂处植骨、螺钉和横突钢丝内固定１５例，短节段经椎寻根内固定３５例，其中改良Ｄｉｃｋ法７例．Ｓｔｅｆｆｅｅ槽式钢板２８例，同时行后外侧融合。作者认为，症状性的腰椎峡部裂或轻微滑脱，峡部可直接修整植骨、螺钉和横突钢丝固定。滑脱椎可采用经椎弓根Ｓｔｅｆｆｅｅ槽式钢板螺钉得到完全或部分复位．     

A biomechanical study of lumbar spondylolysis based on a three-dimensional finite element method.

Biomechanical analyses under compression only, and for a combination of flexion, extension, rotation, and lateral bending were performed to evaluate the stress of the interarticular portion of the lumbar vertebra using a nonlinear three-dimensional finite element method. A detailed three-dimensional L4-L5 motion segment model was developed that took into consideration the material nonlinearities of ligaments and annular fibers and the contact nonlinearities of facet joints. For a more accurate examination, the separation of cortical bone and cancellous bone for both posterior and anterior elements were also considered. The stress in the pars interarticularis was weakest under compression alone, but stronger under compression with lateral bending loading, with flexion, with rotation, and with extension. Under each loading condition, the region of the stress concentration was consistent with the separated region of the spondylolysis observed in clinical situations. Since the stress in the pars interarticularis was high under extension and rotation in particular, those loadings were suggested to be relatively high risk factors leading to spondylolysis.     

Surgical management of adult spondylolysis and spondylolisthesis

The surgical management of spondylolisthesis depends on the type of spondylolisthesis, the grade of slip, and the clinical setting. The surgical approaches may broadly be divided into decompression alone, fusion alone, and a combination of decompression and fusion. Fusion options can be further subdivided into non-instrumented vs. instrumented, anterior vs. posterior, with or without interbody support, and/or combined approaches, often referred to as circumferential fusions. The indication for surgical treatment of spondylolysis is persistent, disabling back pain refractory to conservative management. In conclusion, an evidence-based approach combined with shared decision making with informed patients will lead to successful outcomes.     

Nonoperative treatment for painful adolescent spondylolysis or spondylolisthesis

Eighty-two adolescent patients with symptomatic spondylolysis or spondylolisthesis were treated by nonoperative modalities. Patients' ages ranged from 6.5 to 21 years, and follow-up ranged from 1 to 14.3 years. Thirty-one patients became asymptomatic, 17 had significant but incomplete relief of pain, nine had no relief, and 25 required surgical treatment for pain. Of 12 patients with grade 3 or 4 slip, only one had significant relief of pain, whereas 48 of 70 patients with lesser degrees of slip had significant relief of pain. Nonoperative treatment of degrees of spondylolisthesis of less than or equal to grade 2 can reliably relieve pain in two-thirds of patients.     

Magnetic resonance tomography in spondylolysis and spondylolisthesis

40 patients with spondylolisthesis and/or spondylolysis were studied by magnetic resonance imaging (MR), 12 of whom with correlation to CT. CT proved to be more sensitive in detecting pars defects than MR. Sagittal MR, however, was more accurate in assessing spondylolisthesis than axial CT. At present, CT is superior to MR in demonstrating bony abnormalities. MR appears indicated in the patient undergoing spinal fusion in whom detection of intervertebral disc degeneration in the levels above or below intended fusion may lead to extension of fusion to the degenerated levels. Lack of ionizing radiation makes MR an ideal diagnostic method in evaluating spondylolisthesis in children and adolescents.     

Nerve root compression in spondylolysis and spondylolisthesis

Thirty-four bony specimens of isthmic spondylolysis were examined and, in a significant number (32%), stenosis of the intervertebral foramen was noted. Although not emphasised in previous reports, this finding may be an important factor in the aetiology of nerve root compression when this is associated with spondylolysis and spondylolisthesis. Anatomical guidelines for adequate surgical decompression are suggested.