Pars interarticularis

BACKGROUND CONTEXT: Isthmic spondylolisthesis (IS) is defined as the anterior translation of one lumbar vertebra relative to the next caudal segment as a result of a unilateral or bilateral fracture of the pars interarticularis. These fractures are interchangeably known as "pars defects" or "spondylolysis". Many risk factors have been proposed to explain the progression of a spondylolytic defect to IS, however, none are validated. PURPOSE: This systematic review provides an overview of various radiological and imaging parameters that can help predict the risk of progression of a spondylolytic defect into IS...

INTRODUCTION: The smiley face rod method is an effective treatment for symptomatic terminal-stage spondylolysis. However, the risk factors for treatment failure are unknown. We investigated the association of pars defect type with the treatment outcomes of this method. METHODS: We retrospectively examined data from 34 patients (18.0±6.7 years) with terminal-stage spondylolysis who underwent surgery using the smiley face rod method. The mean follow-up period was 44...

BACKGROUND: Lumbar spondylolysis involves a bony defect in the vertebral pars interarticularis, predominantly affecting the lower lumbar spine. This condition is a significant etiological factor in lumbar instability and recurrent lower back pain, particularly in young individuals. While conservative treatments are the primary intervention, they often fail to provide relief, necessitating surgical approaches. Notwithstanding, executing bone grafting and fixation in the pars interarticularis defect simultaneously through minimally invasive surgery remains challenging...

OBJECTIVE: To determine the effects of thoracic stiffness on mechanical stress in the lumbar spine during motion. METHODS: To evaluate the effect of preoperative thoracic flexibility, stiff and flexible spine models were created by changing the material properties of ligaments and discs in the thoracic spine. Total laminectomy was performed at L4/5 in stiff and flexible models. A biomechanical investigation and finite element analysis were performed preoperatively and postoperatively...

Recurrent stress on the isthmic pars interarticularis often leads to profound injury and symptom burden. When conservative and medical management fail, there are various operative interventions that can be used. The current review details the common clinical presentation and treatment of pars injury, with a special focus on the emerging minimally invasive procedures used in isthmic pars interarticularis repair. PubMed and Google Scholar database literature reviews were conducted. The keywords and phrases that were searched include but were not limited to; "history of spondylolysis", "pars interarticularis", "pars defect", "conventional surgical repair of pars", and "minimally invasive repair of pars"...

OBJECTIVE: Isthmic spondylolisthesis (IS) is distinguished by a congenital defect or acquired fracture of the pars interarticularis. Numerous studies on L5 low-grade IS have been carried out; however, there is a paucity of data regarding the condition of L5 IS concomitant with L4/5 disc herniation. This study aimed to identify the incidence rate and to illustrate the possible risk factors for L4/5 disc herniation in L5 low-grade IS patients. METHODS: A total of 268 consecutive patients diagnosed as L5/S1 low-grade IS between May 2017 and May 2022 were retrospectively enrolled in this study...

PURPOSE: The optimal management of hangman's fractures is controversial and the standard of care has been neither established nor supported by strong evidence. The Judet approach has been introduced in 1970 as surgical option to treat selected cases of hangman's fractures, harboring the advantage to preserve motion of the craniovertebral junction and to restore the C2 vertebra anatomy by insertion of transpedicular screws through the fracture line. This paper reviews the literature on hangman's fractures surgically managed by Judet approach, and reports two new illustrative cases...

INTRODUCTION: Pedicle stress fractures are an uncommon type of non-union often associated with contralateral neural arch interruption in young, active patients. Patients present with long-lasting low back pain, and the diagnosis is usually delayed. Treatment is generally conservative. Few cases treated surgically are described in the literature, with a high degree of treatment heterogeneity and no consensus on optimal treatment. PRESENTATION OF CASE: A 24-year-old male, following a sports-related trauma, developed persistent lower back pain...

Isthmic spondylolysis results in fracture of pars interarticularis of the lumbar spine, found in as many as half of adolescent athletes with persistent low back pain. While computed tomography (CT) is the gold standard for the diagnosis of spondylolysis, the use of ionizing radiation near reproductive organs in young subjects is undesirable. While magnetic resonance imaging (MRI) is preferable, it has lowered sensitivity for detecting the condition. Recently, it has been shown that ultrashort echo time (UTE) MRI can provide markedly improved bone contrast compared to conventional MRI...

INTRODUCTION AND IMPORTANCE: Traumatic subluxation of C2-C3 with Atlanto-Axial dislocation is very rare and uncommon condition. Only a very few case reported. What constitutes appropriate management in cases of traumatic C2-C3 subluxation with Atlato-axial dislocation is still controversial due to the infrequency of this injury. We managed a patient who had traumatic C2-C3 subluxation with Atlanto-axial dislocation following a history of trauma through posterior approach successfully...

OBJECTIVES: To assess how pars interarticularis fracture characteristics on T1-VIBE and STIR MRI relate to healing and identify anatomical parameters that may impact healing. MATERIALS AND METHODS: A retrospective review of an MRI series of lumbar pars interarticularis injuries in elite athletes over a 3-year period. Fracture configurations, signal intensities and anatomical parameters were recorded by two radiologists. Statistical analysis employed multilevel mixed-effects linear regressions, adjusted for repeated measures and baseline covariates...

INTRODUCTION: Lumbar spondylolysis is a common fatigue fracture of the pars interarticularis of the lamina of the lumbar spine in adolescent athletes presenting with pars clefts. Some pseudarthrotic lumbar spondylolysis causes low back pain or radiculopathy. This study presents a case of pseudarthrotic lumbar spondylolysis that was successfully treated using a modified smiley face rod technique. TECHNICAL NOTE: We developed a modified smiley face rod technique, which places pedicle screws in the lateral edge of the pedicle to preserve the erector spinae muscles and inserts a U-shaped rod between the spinous processes to preserve the supraspinous ligament...

OBJECTIVES: The aims were to (1) prospectively observe the incidence of bone marrow oedema in asymptomatic adult male domestic professional cricketers during a season and evaluate its relationship to the development of lumbar bone stress injury and (2) further understand the practicalities of implementing a Magnetic Resonance Imaging-based screening program to prevent lumbar bone stress injury in New Zealand cricket. DESIGN: Prospective observational cohort. METHODS: Adult male pace bowlers received 6-weekly pre-planned Magnetic Resonance Imaging scans over a single season to determine the presence and intensity of bone marrow oedema in the posterior vertebral arches of the lumbar spine...

The anatomy and pathogenesis of spondylolysis has been widely studied; however, the microanatomy of spondylolysis of the lumbar vertebra has not been well described. Therefore, we aim to better elucidate this anatomy. Twenty dry bone specimens of healed and unhealed spondylolysis of the L5 vertebra were collected from human skeletal remains. Twelve L5 vertebrae were examples of unhealed spondylolysis and eight specimens exhibited a healed (i.e., bony fusion of the lesion) spondylolysis lesion. The specimens underwent macro and microanatomical analysis followed by CT and microCT imaging...

INTRODUCTION: Hangman's fracture, also known as traumatic spondylolisthesis of the axis, is defined as a bilateral fracture of the C2 pars interarticularis. In 1965, Schneider used this term to describe a pattern of similarities seen in fractures associated with judicial hangings. However, this fracture pattern is only observed in approximately 10% of injuries associated with hangings. CASE REPORT: We present a case of an atypical hangman's fracture caused by a headlong dive into a swimming pool and striking the pool's bottom...

Introduction  A unilateral or bilateral pars interarticularis defect (spondylolysis) is a leading cause of axial back pain in adolescent athletes. Currently, a spectrum of imaging modalities is used for assessment of pars interarticularis defects. Objectives  The aim of this study is to compare the accuracy of chemical shift sequence (magnetic resonance imaging [MRI]) technique to conventional MRI sequences in the detection of pars defects. Patients and Methods  Conventional T1, T2, and short tau inversion recovery sagittal and axial, as well as "in-" and "out-" phase chemical shift sagittal MRI sequences of 70 consecutive patients referred for low back pain were reviewed...

INTRODUCTION: The atypical anatomy of the C2 vertebra has led to terminological discrepancies within reports and studies in the literature regarding the location of its pedicle, pars interarticularis, and isthmus. These discrepancies not only limit the power of morphometric analyses, but they also confuse technical reports regarding operations involving C2, and thus confuse our ability to properly communicate this anatomy. Herein, we examine the variations in nomenclature regarding the pedicle, pars interarticularis, and isthmus of C2, and via an anatomical study, propose new terminology...

Spondylolisthesis is characterized by the displacement of one vertebral body in relation to the adjacent vertebra. It is commonly observed in the lower lumbar region and can be caused by a variety of factors, including spondylolysis (a fracture in the pars interarticularis) or degenerative disease. Magnetic resonance imaging (MRI) is becoming increasingly popular as the primary modality for evaluation of low back pain and is often used in the absence of radiographs or Computed Tomography. However, it can be challenging for radiologists to differentiate between the two types of spondylolisthesis based on MRI alone...

PURPOSE: Surgical management of far lateral disc herniations remains challenging. Current transforaminal full-endoscopic approaches require non-visualized docking in the Kambin's triangle and have been associated with significant risk of inadvertent nerve injury. We develop a full-endoscopic approach based on reliable bony landmarks allowing for visualization of the exiting nerve root prior to the far lateral discectomy. METHODS: The surgical details of a full-endoscopic trans-pars interarticularis approach for far lateral discectomy are described...

Lumbar spondylolysis involves anatomical defects of the pars interarticularis, which causes instability during motion. The instability can be addressed through instrumentation with posterolateral fusion (PLF). We developed a novel pedicle screw W-type rod fixation system and evaluated its biomechanical effects in comparison with PLF and Dynesys stabilization for lumbar spondylolysis via finite element (FE) analysis. A validated lumbar spine model was built using ANSYS 14.5 software. Five FE models were established simulating the intact L1-L5 lumbar spine (INT), bilateral pars defect (Bipars), bilateral pars defect with PLF (Bipars_PLF), Dynesys stabilization (Bipars_Dyn), and W-type rod fixation (Bipars_Wtyp)...