Skip to content

Decompression & Resection

Surgical decompression and resection for neural compression, including minimally invasive techniques, open osteotomies, and neoplasm resections.

Overview

Anterior decompression for epidural compression by malignant tumors allows a large number of patients to regain the ability to walk [1], while posterior decompression and stabilization for spinal metastases yields similar results with less morbidity [11]. For degenerative lumbar canal stenosis, microscopic tubular unilateral laminotomy for bilateral decompression is a viable alternative to traditional open decompression, though broader validation in multicenter trials is needed [2]. In the setting of sacrococcygeal chordoma, a posterior approach is satisfactory for resection even at cephalic levels, with acceptable rates of operative and functional morbidity [24].

Absolute surgical indications for disc herniation include deteriorating neurological deficits with myelopathy or cauda equina syndrome [25]. Complete surgical excision of vertebral chordomata has been impossible, but worthwhile relief from pressure symptoms has been achieved by laminectomy and partial resection [10]. En bloc tumor resection with combined surgical approach and effective reconstructions can improve oncologic and functional prognosis in carefully selected spinal tumor patients, although complications may occur [4].

Regarding degenerative spondylolisthesis, the addition of dynamic stabilization to decompression does not yield significant benefits [3], and the NORDSTEN/DS trial has the potential to provide Level 1 evidence regarding whether decompression alone should be advocated as the preferred method [13]. Anterior removal of the intervertebral disc and interbody fusion offers less morbidity than laminectomy, foramen decompression, or posterior fusion, while allowing removal of a degenerated disc without disturbing the spinal canal [20]. This approach also permits interbody fusion at the specific intervertebral level from which symptoms arise [20].

Anatomy & Pathophysiology

Kinematics and Biomechanics

L4–5 dislocation may represent a variant of lumbosacral (L5-S1) dislocation resulting from hyperextension injury [27]. Kinematic MRI reveals dynamic pathoanatomical changes, including position-dependent canal stenosis, in patients with cervical spinal cord injury without fracture and dislocation [28]. Patients with Hirayama disease exhibit distinct cervical biomechanics compared to non-pathological individuals, a divergence that may precipitate cervical hypermobility and overload [53]. Interspinous devices reduce extension range of motion and disc pressure but often fail to fully compensate for destabilization in other planes or at adjacent levels [29]. In the lumbar spine, the movement-preserving properties of total disc replacement are not major determinants of clinical outcomes [30]. Finite element analysis indicates that cervical vertebrae demonstrate good biomechanical performance and stability following percutaneous posterior endoscopic cervical discectomy [31]. Conversely, osteoporosis deteriorates the biomechanical characteristics of the adjacent segment disc after percutaneous transforaminal endoscopic discectomy, potentially increasing the incidence of adjacent segment disease [37].

Surgical Resection and Stability

Following unilateral and bilateral facetectomy, extreme caution is required when placing the spine into extension and axial rotation to avoid biomechanical compromise [32]. Reducing the extent of facetectomy may lower the risk of biomechanical deterioration and subsequent failed back surgery syndrome [34]. The static biomechanical effects of modified anterior cervical discectomy and fusion are intermediate between standard ACDF and anterior cervical corpectomy and fusion [38]. Furthermore, the risk of vertebral body collapse is lower with modified ACDF than with ACCF [38]. While existing evidence supports the biomechanical advantage of the anterior reduction method over the posterior lever reduction method for lumbar spondylolisthesis [40], further biomechanical tests and clinical studies are required to confirm Tektona®'s capabilities for height and volume restoration in osteoporotic vertebral compression fractures [39].

Alignment and Adjacent Segment Management

Restoring sagittal alignment matched to spinopelvic morphology during degenerative lumbar surgery can optimize outcomes by preventing adjacent segment pathology [43]. Topping-off technology decreases stress and range of motion in the adjacent upper degenerated segment while increasing the range of motion in other upper segments, thereby protecting degenerated segments and compensating for lumbar mobility [50]. Decompression coupled with dynamic stabilization techniques more effectively alleviates postoperative lumbar stiffness and functional impairment compared to traditional decompression combined with rigid fusion [48]. Unilateral dynamic stabilization presents promising results regarding stability, improved clinical outcomes, and reduced operation time and cost for patients with unilateral spinal pathologies [51].

Reduction Techniques and Examination

Physical examination of the spine includes inspection, palpation, range of motion testing, and neurologic evaluation to identify spinal pathology, nonspinal conditions, and signs of symptom magnification [45]. Direct reduction of high-grade lumbosacral spondylolisthesis using an anterior cantilever technique achieved a high fusion rate, partially reduced slippage, and significantly improved the lumbosacral angle while minimizing common complications [46].

Classification

Malignant Tumor Decompression: Anterior decompression for epidural compression by malignant tumors can result in patients regaining the ability to walk [1]. En bloc tumor resection with combined surgical approach and effective reconstructions can improve oncologic and functional prognosis in carefully selected spinal tumor patients, although complications may occur [4]. En bloc resection and anterior column reconstruction is accompanied by a high incidence of complications, especially when a combined approach is necessary [58].

Lumbar Stenosis and Spondylolisthesis: Microscopic tubular unilateral laminotomy is a viable alternative to traditional open decompression for bilateral decompression in lumbar canal stenosis [2]. The addition of dynamic stabilization to decompression does not yield significant benefits for degenerative lumbar spondylolisthesis [3]. The NORDSTEN/DS trial has the potential to provide Level 1 evidence regarding whether decompression alone should be advocated as the preferred method for degenerative spondylolisthesis [13].

Cage Retropulsion: A practical classification system for cage retropulsion in degenerative lumbar disease has been proposed with preliminary feasibility in surgical approach selection [44]. Early revision may yield better outcomes for cage retropulsion in degenerative lumbar disease [44].

Thoracolumbar Fractures: Controversies exist regarding diagnostic tools, classification systems, and the evidence for conservative and surgical methods for thoracolumbar fractures without neurological impairment [14]. A reliable classification for assessing the stability of a healed vertebra after posterior short-segment fixation for thoracolumbar burst fractures was developed [47].

Subaxial Cervical Trauma: Definitive management of subaxial cervical spine trauma, whether surgical or nonsurgical, is based on the assessment of mechanical instability of the injury [59]. Definitive management of subaxial cervical spine trauma, whether surgical or nonsurgical, is based on the presence or absence of neurologic impairment [59]. Definitive management of subaxial cervical spine trauma, whether surgical or nonsurgical, is based on various patient factors that may influence outcome [59].

Other Considerations: Removal of intradural neurofibroma lesions resulted in complete relief of symptoms in most cases, despite all patients having neurological deficits at the time of definitive surgery [5]. Direct decompression of a ganglion cyst of the spinoglenoid notch does not lead to different results compared to SLAP repair alone [8]. Patients treated with posterior or combined anterior and posterior arthrodesis were far more likely to develop clinical adjacent-segment pathology requiring surgery than those treated with posterior decompression or anterior arthrodesis [9]. Anterior removal of the intervertebral disc and interbody fusion has less morbidity than laminectomy and foramen decompression or posterior fusion [20]. The operation of anterior removal of the intervertebral disc and interbody fusion allows removal of a degenerated disc without disturbing the spinal canal [20]. The operation of anterior removal of the intervertebral disc and interbody fusion permits interbody fusion at the specific intervertebral level from which symptoms arise [20]. Alternative operative approaches or preparations may be necessary for the management of large sacral dural defects in Marfan syndrome [57].

Clinical Presentation

The clinical presentation of spinal pathology varies by etiology but often centers on neurological deficits and functional impairment. Patients with intradural neurofibroma may present with symptoms mimicking lumbar-disc disease, frequently accompanied by neurological deficits at the time of definitive surgery [5]. Similarly, epidural compression from malignant tumors can manifest as an inability to walk, which may be restored following anterior decompression [1]. For cervical spondylotic myelopathy, the most favorable postoperative outcomes are observed in patients presenting with early mild findings, those managed within six months to one year of symptom onset, and those demonstrating a postoperative spinal cord transverse area greater than forty square millimeters [19].

Specific etiologies present with distinct clinical patterns requiring targeted assessment. Posterior paravertebral ossification causing cervical myelopathy typically presents with difficulty walking and sensory disturbance, for which laminectomy provides valuable decompression [15]. Solitary eosinophilic granuloma of a vertebral body can cause paraplegia, yet good functional recovery is achievable with posterior decompression and local radiation therapy [6]. In cases of lumbar epidural lipomatosis, clinical courses are generally satisfactory following laminectomy [17]. Symptomatic sacral meningeal cysts may also be managed surgically to yield long-term symptom resolution in appropriately selected patients [16].

Urgent surgical intervention is mandated for specific red-flag patterns. Regardless of the setting, the diagnosis of cauda equina syndrome requires urgent surgical decompression of the spinal canal [36]. For metastatic cervical spine tumors, management decisions must be stratified based on histology, clinical presentation, patient prognosis, and spinal stability [35].

Chronic or degenerative conditions often require nuanced decision-making regarding decompression and stabilization. Microscopic tubular unilateral laminotomy for bilateral decompression serves as a viable alternative to traditional open decompression for lumbar canal stenosis [2]. However, the addition of dynamic stabilization to decompression does not yield significant benefits for degenerative lumbar spondylolisthesis [3]. Patients treated with posterior or combined anterior and posterior arthrodesis are far more likely to develop clinical adjacent-segment pathology requiring surgery compared to those treated with posterior decompression or anterior arthrodesis [9]. A systematic approach involving patient assessment, differential diagnosis formulation, and familiarity with surgical approaches is required for adult patients presenting with late or chronic complications after spinal surgery [33].

Oncologic resection strategies depend on tumor type and patient selection. En bloc tumor resection with a combined surgical approach and effective reconstruction can improve oncologic and functional prognosis in carefully selected spinal tumor patients, though complications may occur [4]. Preoperative clinical and pathological factors are critical considerations for patients undergoing en bloc resection [7]. While complete surgical excision of vertebral chordomata is often impossible, laminectomy and partial resection can achieve worthwhile relief from pressure symptoms [10]. Surgical management of solitary osteochondroma of the twelfth rib with intraspinal extension, involving complete tumor excision with thoracolumbar fixation and fusion, has resulted in symptom improvement and no recurrence at one year [18].

For benign cystic lesions, the choice of procedure influences outcomes. Direct decompression of a ganglion cyst of the spinoglenoid notch does not lead to different results compared to SLAP repair alone [8]. In cases of intradural neurofibroma, removal of the lesion resulted in complete relief of symptoms in most cases [5].

Investigations

MRI: Magnetic resonance imaging is indicated for patients presenting with increasing symptoms or neurological deficits, particularly during reduction attempts for extrusion of an intervertebral disc associated with traumatic subluxation or dislocation of cervical facets [55]. Preoperative MRI showing erosions in acute shoulder infection suggests that open debridement is more likely to be appropriate than arthroscopic debridement [63]. Technological advances including CT, MRI, and SPECT were critical for the accurate diagnosis of fractures of the lumbar lamina with epidural hematoma simulating herniation of a disc, thereby avoiding unnecessary surgery [62].

CT: Technological advances including CT, MRI, and SPECT were critical for the accurate diagnosis of fractures of the lumbar lamina with epidural hematoma simulating herniation of a disc and avoiding unnecessary surgery [62].

Other Considerations: Preoperative clinical and pathological factors are important considerations for patients undergoing en bloc resection for spinal tumors [7]. Careful clinical and radiologic assessment should be performed for solid-variant aneurysmal bone cysts to tailor an appropriate surgical plan to prevent recurrence and neurologic sequelae [66]. Preoperative imaging studies cannot predict the clinical outcome of percutaneous lumbar discectomy [60]. Myelography provides the most reliable preoperative information for guiding cervical disc excision [61].

Treatment

Non-Operative

Conservative management serves as a primary consideration for specific pathologies where symptoms can be controlled or spontaneous resolution is possible. For large-sized lumbar facet synovial cysts, conservative treatment is a first-line option to prevent unnecessary surgery if symptoms are manageable [52], although nonsurgical management for lumbar facet cysts is associated with a high rate of recurrence and relatively low satisfaction [54]. Similarly, the magnitude of outcome differences between surgery and conservative treatment for rotator cuff tears may be small, with conservative success rates potentially being high [21].

Operative

Indications: Absolute surgical indications include deteriorating neurological deficits with myelopathy or cauda equina syndrome in disc herniation [25], as well as progressive neurological deficits in thoracic myelopathy caused by cervicothoracic diastematomyelia [49]. For degenerative lumbar spondylolisthesis, the NORDSTEN/DS trial aims to provide Level 1 evidence regarding whether decompression alone should be advocated as the preferred method [13]. In cases of recurrent lumbar disk herniation, surgical intervention is indicated when there is concomitant segmental instability or significant foraminal stenosis [64].

Surgical Approach / Technique: Anterior decompression for epidural compression by malignant tumors allows a large number of patients to regain the ability to walk [1]. Posterior decompression and stabilization for spinal metastases yield results similar to anterior decompression but with less morbidity [11]. Microscopic tubular unilateral laminotomy for bilateral decompression is a viable alternative to traditional open decompression for lumbar canal stenosis, though broader validation in multicenter trials is needed [2]. En bloc tumor resection with a combined surgical approach and effective reconstruction can improve oncologic and functional prognosis in carefully selected spinal tumor patients, despite the presence of complications [4]. A posterior approach is satisfactory for resection of sacrococcygeal chordoma even at cephalic levels, with acceptable rates of operative and functional morbidity [24]. Complete surgical excision of vertebral chordomata has been impossible, but worthwhile relief from pressure symptoms has been achieved by laminectomy and partial resection [10]. Direct decompression of a ganglion cyst of the spinoglenoid notch does not lead to different results compared to SLAP repair alone [8]. Selective decompression and fusion is a safe and effective method for multi-segment lumbar spinal stenosis with single-segment degenerative spondylolisthesis, offering shorter operative time, less blood loss, and more preservation of spinal motion segments compared with multi-segmental decompression and fusion [42]. Surgical management involving complete tumor excision with thoracolumbar fixation and fusion for solitary osteochondroma of the twelfth rib with intraspinal extension resulted in symptom improvement and no recurrence at 1 year [18]. Good recovery of function occurred after posterior decompression and local radiation therapy for solitary eosinophilic granuloma of a vertebral body causing paraplegia [6].

Adjuncts: The addition of dynamic stabilization to decompression does not yield significant benefits for degenerative lumbar spondylolisthesis [3]. Additional operations after primary disc surgery are needed more frequently than previously reported, and the outcome profoundly deteriorates after the second additional operation [12]. Decompression of a nerve root by excision of a lumbar disc is usually successful in treating radicular pain, but failures are primarily due to disabling low-back pain or recurrent herniation [41]. A review attempts to elucidate controversies regarding diagnostic tools, classification systems, and the evidence for conservative and surgical methods for thoracolumbar fractures without neurological impairment [14].

Complications

Neurological Outcomes: Anterior decompression for epidural compression by malignant tumors allows a large number of patients to regain the ability to walk [1]. Neurological survivorship following primary decompressive surgery for degenerative cervical myelopathy is 89.3% at 5 years and 77.3% at 10 years [22]. Surgical decompression by laminectomy is valuable for posterior paravertebral ossification causing cervical myelopathy when the patient's chief complaints are difficulty in walking and sensory disturbance [15]. Patients with intradural neurofibroma simulating lumbar-disc disease had neurological deficits at the time of definitive surgery, and removal of the lesions resulted in complete relief of symptoms in most cases [5]. Good recovery of function occurred after posterior decompression and local radiation therapy for solitary eosinophilic granuloma of a vertebral body causing paraplegia [6].

Instability and Adjacent Segment Pathology: Patients treated with posterior or combined anterior and posterior arthrodesis were far more likely to develop clinical adjacent-segment pathology requiring surgery than those treated with posterior decompression or anterior arthrodesis [9]. The addition of dynamic stabilization to decompression does not yield significant benefits for degenerative lumbar spondylolisthesis [3]. Long-term outcomes for posterior decompression and fusion surgery for thoracic ossification of the posterior longitudinal ligament revealed that while cervical and lumbar spinal lesions led to reoperations, they did not affect quality of life, and relative improvement was maintained even after 10 years [23]. Additional operations after primary disc surgery are needed more frequently than previously reported, and the outcome profoundly deteriorates after the second additional operation [12].

Oncologic Resection and Reconstruction: En bloc tumor resection with combined surgical approach and effective reconstructions can improve oncologic and functional prognosis in carefully selected spinal tumor patients, although complications may occur [4]. Preoperative clinical and pathological factors are important considerations for patients undergoing en bloc resection for spinal tumors [7]. Complete surgical excision of vertebral chordomata has been impossible, but worthwhile relief from pressure symptoms has been achieved by laminectomy and partial resection [10]. Posterior decompression and stabilization for spinal metastases yielded results similar to those attained after anterior decompression but with less morbidity [11].

Approach-Specific Morbidity: Microscopic tubular unilateral laminotomy for bilateral decompression is a viable alternative to traditional open decompression, though broader validation in multicenter trials is needed [2]. Anterior removal of the intervertebral disc and interbody fusion has less morbidity than laminectomy and foramen decompression or posterior fusion [20]. Clinical courses were satisfactory after laminectomy for lumbar epidural lipomatosis [17]. At short-term follow-up, subacromial decompression did not seem to significantly affect the outcome of arthroscopic rotator cuff repair [26].

Other Considerations: Evidence regarding specific complication categories such as infection, aseptic loosening, periprosthetic fracture, thromboembolism, patellar/extensor-mechanism failure, stiffness, nerve palsy, wound complications, and polyethylene wear is not present in the provided evidence base for this section.

Recovery

Light activity (weeks): Evidence regarding specific week ranges for light activity is not provided in the current evidence base. However, patients undergoing anterior decompression for epidural compression by malignant tumors may regain the ability to walk [1], and those with lumbar epidural lipomatosis report satisfactory clinical courses after laminectomy [17]. For symptomatic sacral meningeal cysts, long-term resolution of symptoms is achievable in appropriately selected patients following obstruction of communicating holes with muscle grafts [16].

Full activity (months): Specific month ranges for full activity are not detailed in the provided evidence. Long-term outcomes for posterior decompression and fusion surgery for thoracic ossification of the posterior longitudinal ligament demonstrate that relative improvement is maintained even after 10 years [23]. Similarly, removal of intradural neurofibromas resulted in complete relief of symptoms in most cases, despite all patients having neurological deficits at the time of definitive surgery [5].

Complete recovery / outcome plateau (months): The best postoperative results for cervical spondylotic myelopathy are obtained for patients managed with decompression within six months to one year after symptom onset [19]. Neurological survivorship following primary decompressive surgery for degenerative cervical myelopathy is 89.3% at 5 years and 77.3% at 10 years [22]. Additionally, the outcome of lumbar disc surgery profoundly deteriorates after the second additional operation, necessitating more frequent additional operations than previously reported [12].

Rehabilitation protocol: No specific rehabilitation protocols, PT phasing, or immobilisation durations are described in the available evidence.

Functional milestones: Functional outcomes are influenced by specific preoperative and postoperative factors. The best postoperative results for cervical spondylotic myelopathy are obtained for patients with early mild findings [19] and those with a postoperative spinal cord transverse area greater than forty square millimeters [19]. Developmental canal stenosis did not affect neurologic improvement postoperatively at short-term follow-up in patients with cervical spondylotic myelopathy undergoing anterior decompression and fusion [56].

Other Considerations: Surgical approaches vary in morbidity and efficacy based on pathology. Posterior decompression and stabilization for spinal metastases yielded results similar to anterior decompression but with less morbidity [11]. The addition of dynamic stabilization to decompression does not yield significant benefits for degenerative lumbar spondylolisthesis [3]. Microscopic tubular unilateral laminotomy for bilateral decompression is a viable alternative to traditional open decompression for lumbar canal stenosis, though broader validation in multicenter trials is needed [2]. Preoperative clinical and pathological factors are important considerations for patients undergoing total en bloc spondylectomy for spinal tumours [7]. Surgical decompression by laminectomy is valuable for posterior paravertebral ossification causing cervical myelopathy when the patient's chief complaints are difficulty in walking and sensory disturbance [15]. Good recovery of function occurred after posterior decompression and local radiation therapy for solitary eosinophilic granuloma of a vertebral body causing paraplegia [6]. At short-term follow-up, subacromial decompression did not significantly affect the outcome of arthroscopic rotator cuff repair [26]. Cervical and lumbar spinal lesions led to reoperations in patients undergoing posterior decompression and fusion surgery for thoracic ossification of the posterior longitudinal ligament, but these did not affect quality of life [23].

Key Evidence

  • [L4] In view of the large number of patients who regained the ability to walk after anterior decompression, the role of surgical intervention as a primary treatment for epidural compression by a malignant tumor should be reconsidered. (10.2106/00004623-198567030-00004)
  • [L4] The findings suggest it is a viable alternative to traditional open decompression, though broader validation in multicenter trials is needed. (10.1186/s13018-025-06564-8)
  • [L1] The addition of dynamic stabilization to decompression does not yield significant benefits. (10.1186/s13018-025-06550-0)
  • [Case_report] Although with complications, en bloc tumor resection with combined surgical approach and effective reconstructions could improve oncologic and functional prognosis in carefully selected spinal tumor patients. (10.1186/s12891-021-04208-6)
  • [L4] All patients had neurological deficits at the time of definitive surgery, and removal of the lesions resulted in complete relief of symptoms in most cases. (10.2106/00004623-197658070-00031)
  • [L4] Good recovery of function occurred after posterior decompression and local radiation therapy. (10.2106/00004623-196648080-00014)
  • [L3] In addition to preoperative clinical and pathological factors, it is therefore important to consider these factors in patients who undergo en bloc resection for spinal tumours. (10.1302/0301-620x.103b5.bjj-2020-1777.r1)
  • [L2] Furthermore, direct decompression of the cyst does not lead to different results. (10.1016/j.jse.2012.01.013)
  • [L3] Patients treated with posterior or combined anterior and posterior arthrodesis were far more likely to develop clinical adjacent-segment pathology requiring surgery than those treated with posterior decompression or anterior arthrodesis. (10.2106/jbjs.m.01482)
  • [L4] Complete surgical excision of vertebral chordomata has been impossible, but worthwhile relief from pressure symptoms has been achieved by laminectomy and partial resection. (10.2106/00004623-195335020-00013)
  • [L3] The results were similar to those attained after anterior decompression but with less morbidity. (10.2106/00004623-199704000-00006)
  • [L3] Additional operations after primary disc surgery are needed more frequently than previously reported, and the outcome profoundly deteriorates after the second additional operation. (10.1302/0301-620x.104b5.bjj-2021-1706.r2)
  • [L2] The NORDSTEN/DS trial has the potential to provide Level 1 evidence of whether decompression alone should be advocated as the preferred method or not. (10.1186/s12891-018-2384-0)
  • [L4] This review attempts to elucidate controversies regarding diagnostic tools, classification systems, and the evidence for conservative and surgical methods based on recent literature. (10.1302/2058-5241.1.000029)
  • [L4] Surgical decompression by laminectomy is valuable when the patient's chief complaints are difficulty in walking and sensory disturbance. (10.2106/00004623-196749070-00007)
  • [L4] Surgical treatment of symptomatic sacral meningeal cysts can yield a long-term resolution of the appropriately selected patient's symptoms. (10.1186/s12891-019-2998-x)
  • [L4] Clinical courses were satisfactory after laminectomy. (10.1186/s12891-018-1988-8)
  • [L4] Surgical management involved complete tumour excision with thoracolumbar fixation and fusion, resulting in symptom improvement and no recurrence at 1 year. (10.1186/1471-2474-13-57)
  • [L5] The best postoperative results are obtained for patients managed with decompression within six months to one year after symptom onset, those with early mild findings, and those with a postoperative spinal cord transverse area greater than forty square millimeters. (10.2106/00004623-199409000-00020)
  • [L4] The operation has less morbidity than laminectomy and foramen decompression or posterior fusion, allows removal of a degenerated disc without disturbing the spinal canal, and permits interbody fusion at the specific intervertebral level from which symptoms arise. (10.2106/00004623-195840030-00009)
  • [L1] However, the magnitude of the difference in outcomes between surgery and conservative treatment may be small and the 'success rate' of conservative treatment may be high, allowing surgeons to be judicious in choosing those patients who are most likely to benefit from surgery. (10.1302/0301-620x.101b9.bjj-2018-1591.r1)
  • [L3] The study reports neurological survivorship of 89.3% at 5 years and 77.3% at 10 years following primary decompressive surgery for DCM. (10.2106/jbjs.22.00218)
  • [L4] The long-term outcomes revealed that although cervical and lumbar spinal lesions led to reoperations, they did not affect QoL, and relative improvement was maintained even after 10 years. (10.2106/jbjs.23.01475)
  • [L4] A posterior approach is satisfactory for resection even at cephalic levels, with acceptable rates of operative and functional morbidity. (10.2106/00004623-199310000-00008)
  • [L5] Absolute surgical indications for disc herniation include deteriorating neurological deficits with myelopathy or cauda equina syndrome. (10.1302/2058-5241.6.210020)
  • [L1] At short-term follow-up, subacromial decompression did not seem to significantly affect the outcome of arthroscopic rotator cuff repair. (10.1016/j.arthro.2006.10.011)
  • [L4] The biomechanics of the lumbar spine may differ with each individual, and L4–5 dislocation may be a variant to lumbosacral (L5-S1) dislocation, owing to hyperextension injury. (10.1186/s12891-019-2921-5)
  • [L4] Kinematic MRI demonstrated dynamic pathoanatomical changes, such as canal stenosis in different positions, in patients with cervical spinal cord injury without fracture and dislocation. (10.1186/s13018-023-03745-1)
  • [L4] The paper reviews biomechanical studies to clarify the effects of interspinous devices on treated and adjacent spinal segments, noting that while devices reduce range of motion in extension and can reduce disc pressure, they often fail to fully compensate for destabilization in other planes or adjacent levels. (10.1155/2014/839325)
  • [L1] This suggests that in the lumbar spine the movement preserving properties of TDR are not major determinants of clinical outcomes. (10.1302/0301-620x.95b1.29829)
  • [L5] From the perspective of finite element analysis, the cervical vertebrae after PPECD treatment showed good biomechanical performance and stability. (10.1186/s13018-019-1113-1)
  • [L5] After unilateral and bilateral facetectomy, care must be taken when placing the spine into extension and axial rotation posture from the biomechanical point of view. (10.1155/2017/7981513)
  • [L5] A systematic approach to treatment is required for the adult patient presenting with late or chronic complications after spinal surgery, involving patient assessment, differential diagnosis formulation, and familiarity with different surgical approaches. (10.5435/jaaos-d-16-00530)
  • [L5] Less facetectomy is better because it may reduce the risk of biomechanical deterioration and consequently, that of FBSS. (10.1186/s12891-019-2751-5)
  • [L5] Management decisions should be based on histology, clinical presentation, patient prognosis, and spinal stability. (10.5435/jaaos-23-01-38)
  • [L5] Regardless of the setting, when cauda equina syndrome is diagnosed, the treatment is urgent surgical decompression of the spinal canal. (10.5435/00124635-200808000-00006)
  • [L5] Osteoporosis leads to the deterioration of biomechanical characteristics in the adjacent segment disc after PTED; this variation may also result in an increase in the incidence of ASD. (10.1186/s13018-019-1166-1)
  • [L5] The static biomechanical effects caused by Mod ACDF are intermediate between ACDF and ACCF, and the risk of vertebral body collapse is lower than that by ACCF. (10.1186/s13018-023-04033-8)
  • [L5] Further biomechanical tests and clinical studies have to proof Tektona®'s capabilities. (10.1186/s12891-020-03899-7)
  • [L5] The existing evidence supports the biomechanical advantage of the anterior reduction method, which might be one of the contributing factors to successfully treating high-grade lumbar spondylolisthesis with short-segment instrumentation. (10.1186/s12891-021-04758-9)
  • [L3] Decompression of a nerve root by excision of a lumbar disc is usually successful in treating radicular pain, but failures are primarily due to disabling low-back pain or recurrent herniation. (10.2106/00004623-198971050-00013)
  • [L3] Selective decompression and fusion is a safe and effective method for the treatment of MLSS, with the advantages of shorter operative time, less blood loss, and more preservation of spinal motion segments when compared with multi-segmental decompression and fusion. (10.1186/s13018-019-1092-2)
  • [L5] Restoring sagittal alignment matched to spinopelvic morphology during degenerative lumbar surgery can optimize surgical outcomes by preventing adjacent segment pathology. (10.5435/jaaos-d-24-00749)
  • [L4] The study proposes a practical classification system with preliminary feasibility in surgical approach selection for cage retropulsion, suggesting that early revision may yield better outcomes. (10.1186/s12891-026-09616-0)
  • [L4] It achieved a high fusion rate, partially reduced slippage, and significantly improved lumbosacral angle, while minimizing common complications. (10.1186/s12891-021-04439-7)
  • [L3] A reliable classification for assessing the stability of a healed vertebra was developed. (10.1186/s12891-020-03386-z)
  • [L3] Compared to traditional decompression combined with rigid fusion surgery, decompression coupled with dynamic stabilization techniques can more effectively alleviate postoperative lumbar stiffness and functional impairment in patients. (10.1186/s13018-025-05837-6)
  • [Case_report] A progressive neurological deficit is an absolute indication for operative treatment. (10.2106/00004623-198971020-00019)
  • [L5] Topping-off technology can decrease the stress and ROM of the adjacent upper degenerated segment, and increase the ROM of other upper segments, thereby protecting the degenerated upper adjacent segments and compensating the lumbar spine mobility. (10.1186/s12891-020-3128-5)
  • [L3] Unilateral dynamic stabilization presents promising results in terms of stability, improved clinical outcomes, and reduced operation time and cost for patients with unilateral spinal pathologies. (10.1186/s12891-024-08097-3)
  • [L5] Conservative treatment should be considered as a first-line option if symptoms can be controlled to prevent unnecessary surgery. (10.1186/s12891-025-08822-6)
  • [L5] Compared with non-pathological people, Hirayama disease patients have differences in cervical biomechanics, which may lead to cervical hypermobility and overload. (10.1186/s13018-022-02984-y)
  • [L4] First-line treatment is nonsurgical management, though it is associated with a high rate of recurrence and relatively low satisfaction. (10.5435/jaaos-d-14-00461)
  • [Case_report] The authors recommend that magnetic resonance imaging be performed for patients with increasing symptoms or neurological deficits, especially during reduction attempts. (10.2106/00004623-199173100-00014)
  • [L3] DCS did not affect neurologic improvement postoperatively at short-term follow-up. (10.1186/s12891-015-0728-6)
  • [Case_report] Alternative operative approaches or preparations for the management of dural defects may be necessary. (10.2106/00004623-199307000-00013)
  • [L4] En bloc resection and anterior column reconstruction is accompanied by a high incidence of complications, especially when a combined approach is necessary. (10.1186/s12891-024-07408-y)
  • [L5] Definitive management (surgical or nonsurgical) is based on the assessment of the mechanical instability of the injury, the presence or absence of neurologic impairment, and various patient factors that may influence outcome. (10.5435/00124635-200602000-00003)
  • [L3] Preoperative imaging studies cannot predict the clinical outcome of percutaneous lumbar discectomy. (10.2106/00004623-199504000-00011)
  • [Case_report] Technological advances including CT, MRI, and SPECT were critical for accurate diagnosis and avoiding unnecessary surgery. (10.2106/00004623-198971050-00023)
  • [L3] Therefore, if preoperative MRI showed erosions, open debridement is more likely to be appropriate than arthroscopic debridement. (10.1016/j.jse.2019.05.010)
  • [L5] Treatment includes aggressive medical management and surgical intervention, with fusion necessary in the presence of concomitant segmental instability or significant foraminal stenosis. (10.5435/00124635-201006000-00005)
  • [L4] Management of injuries to the craniocervical junction remains challenging, but good outcomes can be achieved with a comprehensive plan that consists of accurate and timely diagnosis and stabilization of the craniocervical junction. (10.5435/jaaos-22-11-718)
  • [L4] Solid-variant aneurysmal bone cysts are difficult to diagnose and treat, and careful clinical and radiologic assessment should be done to tailor an appropriate surgical plan to prevent recurrence and neurologic sequelae. (10.5435/jaaos-d-16-00315)

See Also

References

[1] Vertebral body resection for epidural compression by malignant tumors. Results of forty-seven consecutive operative procedures.. The Journal of Bone & Joint Surgery. 1985. DOI: 10.2106/00004623-198567030-00004

[2] Microscopic tubular unilateral laminotomy for bilateral decompression: a detailed surgical illustration and single-arm cohort study on outcomes in lumbar canal stenosis. Journal of Orthopaedic Surgery and Research. 2026. DOI: 10.1186/s13018-025-06564-8

[3] Decompression, decompression plus fusion and decompression plus dynamic stabilization for degenerative lumbar spondylolisthesis: a network meta-analysis. Journal of Orthopaedic Surgery and Research. 2025. DOI: 10.1186/s13018-025-06550-0

[4] En bloc resection and reconstruction of a huge chondrosarcoma involving multilevel upper thoracic spine and chest wall: case report. BMC Musculoskeletal Disorders. 2021. DOI: 10.1186/s12891-021-04208-6

[5] Intradural neurofibroma simulating lumbar-disc disease. Report of six cases. The Journal of Bone & Joint Surgery. 1976. DOI: 10.2106/00004623-197658070-00031

[6] Solitary Eosinophilic Granuloma of a Vertebral Body Causing Paraplegia. The Journal of Bone & Joint Surgery. 1966. DOI: 10.2106/00004623-196648080-00014

[7] Perioperative complications of total en bloc spondylectomy for spinal tumours. The Bone & Joint Journal. 2021. DOI: 10.1302/0301-620x.103b5.bjj-2020-1777.r1

[8] Ganglion cyst of the spinoglenoid notch: comparison between SLAP repair alone and SLAP repair with cyst decompression. Journal of Shoulder and Elbow Surgery. 2012. DOI: 10.1016/j.jse.2012.01.013

[9] Risk-Factor Analysis of Adjacent-Segment Pathology Requiring Surgery Following Anterior, Posterior, Fusion, and Nonfusion Cervical Spine Operations. The Journal of Bone and Joint Surgery-American Volume. 2014. DOI: 10.2106/jbjs.m.01482

[10] CHORDOMA OF LUMBAR VERTEBRA. The Journal of Bone & Joint Surgery. 1953. DOI: 10.2106/00004623-195335020-00013

[11] Posterior Decompression and Stabilization for Spinal Metastases. Analysis of Sixty-seven Consecutive Patients. The Journal of Bone & Joint Surgery*. 1997. DOI: 10.2106/00004623-199704000-00006

[12] Additional operations after surgery for lumbar disc prolapse. The Bone & Joint Journal. 2022. DOI: 10.1302/0301-620x.104b5.bjj-2021-1706.r2

[13] Decompression alone versus decompression with instrumental fusion the NORDSTEN degenerative spondylolisthesis trial (NORDSTEN-DS); study protocol for a randomized controlled trial. BMC Musculoskeletal Disorders. 2019. DOI: 10.1186/s12891-018-2384-0

[14] Thoracolumbar fractures without neurological impairment. EFORT Open Reviews. 2016. DOI: 10.1302/2058-5241.1.000029

[15] Posterior Paravertebral Ossification Causing Cervical Myelopathy. The Journal of Bone & Joint Surgery. 1967. DOI: 10.2106/00004623-196749070-00007

[16] Surgical management of sacral meningeal cysts by obstructing the communicating holes with muscle graft. BMC Musculoskeletal Disorders. 2019. DOI: 10.1186/s12891-019-2998-x

[17] Clinical and imaging characteristics in patients undergoing surgery for lumbar epidural lipomatosis. BMC Musculoskeletal Disorders. 2018. DOI: 10.1186/s12891-018-1988-8

[18] Solitary osteochondroma of the twelfth rib with intraspinal extension and cord compression in a middle-aged patient. BMC Musculoskeletal Disorders. 2012. DOI: 10.1186/1471-2474-13-57

[19] Evaluation and Management of Cervical Spondylotic Myelopathy. The Journal of Bone & Joint Surgery. 1994. DOI: 10.2106/00004623-199409000-00020

[20] The Treatment of Certain Cervical-Spine Disorders by Anterior Removal of the Intervertebral Disc and Interbody Fusion. The Journal of Bone & Joint Surgery. 1958. DOI: 10.2106/00004623-195840030-00009

[21] Surgical repair versus conservative treatment and subacromial decompression for the treatment of rotator cuff tears. The Bone & Joint Journal. 2019. DOI: 10.1302/0301-620x.101b9.bjj-2018-1591.r1

[22] Neurological Survivorship Following Surgery for Degenerative Cervical Myelopathy. Journal of Bone and Joint Surgery. 2022. DOI: 10.2106/jbjs.22.00218

[23] Ten-Year Follow-up of Posterior Decompression and Fusion Surgery for Thoracic Ossification of the Posterior Longitudinal Ligament. Journal of Bone and Joint Surgery. 2024. DOI: 10.2106/jbjs.23.01475

[24] Operative treatment of sacrococcygeal chordoma. A review of twenty-one cases.. The Journal of Bone & Joint Surgery. 1993. DOI: 10.2106/00004623-199310000-00008

[25] Herniated discs: when is surgery necessary?. EFORT Open Reviews. 2021. DOI: 10.1302/2058-5241.6.210020

[26] Arthroscopic Rotator Cuff Repair With and Without Subacromial Decompression: A Prospective Randomized Study. Arthroscopy. 2007. DOI: 10.1016/j.arthro.2006.10.011

[27] Traumatic bilateral L4-5 facet fracture dislocation: a case presentation with mechanism of injury. BMC Musculoskeletal Disorders. 2019. DOI: 10.1186/s12891-019-2921-5

[28] Dynamic evaluation of the cervical spine by kinematic MRI in patients with cervical spinal cord injury without fracture and dislocation. Journal of Orthopaedic Surgery and Research. 2023. DOI: 10.1186/s13018-023-03745-1

[29] Biomechanics of Interspinous Devices. BioMed Research International. 2014. DOI: 10.1155/2014/839325

[30] Segmental mobility, disc height and patient-reported outcomes after surgery for degenerative disc disease. The Bone & Joint Journal. 2013. DOI: 10.1302/0301-620x.95b1.29829

[31] Biomechanical comparison of percutaneous posterior endoscopic cervical discectomy and anterior cervical decompression and fusion on the treatment of cervical spondylotic radiculopathy. Journal of Orthopaedic Surgery and Research. 2019. DOI: 10.1186/s13018-019-1113-1

[32] Effect of Graded Facetectomy on Lumbar Biomechanics. Journal of Healthcare Engineering. 2017. DOI: 10.1155/2017/7981513

[33] An Approach to Lumbar Revision Spine Surgery in Adults. Journal of the American Academy of Orthopaedic Surgeons. 2017. DOI: 10.5435/jaaos-d-16-00530

[34] Reducing the extent of facetectomy may decrease morbidity in failed back surgery syndrome. BMC Musculoskeletal Disorders. 2019. DOI: 10.1186/s12891-019-2751-5

[35] Management of Metastatic Cervical Spine Tumors. Journal of the American Academy of Orthopaedic Surgeons. 2015. DOI: 10.5435/jaaos-23-01-38

[36] Cauda Equina Syndrome. Journal of the American Academy of Orthopaedic Surgeons. 2008. DOI: 10.5435/00124635-200808000-00006

[37] Biomechanical role of osteoporosis affects the incidence of adjacent segment disease after percutaneous transforaminal endoscopic discectomy. Journal of Orthopaedic Surgery and Research. 2019. DOI: 10.1186/s13018-019-1166-1

[38] Static mechanical analysis of the vertebral body after modified anterior cervical discectomy and fusion (partial vertebral osteotomy): a finite element model. Journal of Orthopaedic Surgery and Research. 2023. DOI: 10.1186/s13018-023-04033-8

[39] Height and volume restoration in osteoporotic vertebral compression fractures: a biomechanical comparison of standard balloon kyphoplasty versus Tektona® in a cadaveric fracture model. BMC Musculoskeletal Disorders. 2021. DOI: 10.1186/s12891-020-03899-7

[40] Biomechanical analysis of reduction technique for lumbar spondylolisthesis: anterior lever versus posterior lever reduction method. BMC Musculoskeletal Disorders. 2021. DOI: 10.1186/s12891-021-04758-9

[41] The development of low-back pain after excision of a lumbar disc.. The Journal of Bone & Joint Surgery. 1989. DOI: 10.2106/00004623-198971050-00013

[42] Selective versus multi-segmental decompression and fusion for multi-segment lumbar spinal stenosis with single-segment degenerative spondylolisthesis. Journal of Orthopaedic Surgery and Research. 2019. DOI: 10.1186/s13018-019-1092-2

[43] Segmental Lordosis Restoration During Lumbar Degenerative Spinal Fusion: Surgical Techniques and Outcomes. Journal of the American Academy of Orthopaedic Surgeons. 2024. DOI: 10.5435/jaaos-d-24-00749

[44] Revision surgical treatments and classification system for cage retropulsion in degenerative lumbar disease. BMC Musculoskeletal Disorders. 2026. DOI: 10.1186/s12891-026-09616-0

[45] Chapter 12 Physical Examination of the Spine. 2019.

[46] Direct reduction of high-grade lumbosacral spondylolisthesis with anterior cantilever technique - surgical technique note and preliminary results. BMC Musculoskeletal Disorders. 2021. DOI: 10.1186/s12891-021-04439-7

[47] Healing pattern classification for thoracolumbar burst fractures after posterior short-segment fixation. BMC Musculoskeletal Disorders. 2020. DOI: 10.1186/s12891-020-03386-z

[48] Effects of dynamic stabilization and fusion on postoperative paraspinal muscle degeneration and lumbar function recovery. Journal of Orthopaedic Surgery and Research. 2025. DOI: 10.1186/s13018-025-05837-6

[49] Thoracic myelopathy caused by cervicothoracic diastematomyelia. A case report.. The Journal of Bone & Joint Surgery. 1989. DOI: 10.2106/00004623-198971020-00019

[50] Biomechanical changes of degenerated adjacent segment and intact lumbar spine after lumbosacral topping-off surgery: a three-dimensional finite element analysis. BMC Musculoskeletal Disorders. 2020. DOI: 10.1186/s12891-020-3128-5

[51] Dynamic stabilization for unilateral spinal pathologies: clinical efficacy and safety outcomes. BMC Musculoskeletal Disorders. 2025. DOI: 10.1186/s12891-024-08097-3

[52] Spontaneous regression of large-sized lumbar facet synovial cysts: two case reports and literature review. BMC Musculoskeletal Disorders. 2025. DOI: 10.1186/s12891-025-08822-6

[53] How to reconstruct the lordosis of cervical spine in patients with Hirayama disease? A finite element analysis of biomechanical changes focusing on adjacent segments after anterior cervical discectomy and fusion. Journal of Orthopaedic Surgery and Research. 2022. DOI: 10.1186/s13018-022-02984-y

[54] Evaluation and Treatment of Lumbar Facet Cysts. Journal of the American Academy of Orthopaedic Surgeons. 2016. DOI: 10.5435/jaaos-d-14-00461

[55] Extrusion of an intervertebral disc associated with traumatic subluxation or dislocation of cervical facets. Case report.. The Journal of Bone & Joint Surgery. 1991. DOI: 10.2106/00004623-199173100-00014

[56] Relationship between developmental canal stenosis and surgical results of anterior decompression and fusion in patients with cervical spondylotic myelopathy. BMC Musculoskeletal Disorders. 2015. DOI: 10.1186/s12891-015-0728-6

[57] Large sacral dural defect in Marfan syndrome. A case report.. The Journal of Bone & Joint Surgery. 1993. DOI: 10.2106/00004623-199307000-00013

[58] Perioperative complications of en bloc resection and anterior column reconstruction for thoracic and lumbar spinal tumors. BMC Musculoskeletal Disorders. 2024. DOI: 10.1186/s12891-024-07408-y

[59] Subaxial Cervical Spine Trauma. Journal of the American Academy of Orthopaedic Surgeons. 2006. DOI: 10.5435/00124635-200602000-00003

[60] Percutaneous lumbar discectomy. Preoperative and postoperative magnetic resonance imaging.. The Journal of Bone & Joint Surgery. 1995. DOI: 10.2106/00004623-199504000-00011

[61] Cervical-Disc Resection: A FOLLOW-UP OF MYELOGRAPHIC AND SURGICAL PROCEDURE.. The Journal of Bone and Joint Surgery. American Volume. 1964.

[62] Fractures of the lumbar lamina with epidural hematoma simulating herniation of a disc. A case report.. The Journal of Bone & Joint Surgery. 1989. DOI: 10.2106/00004623-198971050-00023

[63] Treatment of acute shoulder infection: can osseous lesion be a rudder in guideline for determining the method of débridement?. Journal of Shoulder and Elbow Surgery. 2019. DOI: 10.1016/j.jse.2019.05.010

[64] Recurrent Lumbar Disk Herniation. American Academy of Orthopaedic Surgeon. 2010. DOI: 10.5435/00124635-201006000-00005

[65] Upper Cervical Spine Trauma. Journal of the American Academy of Orthopaedic Surgeons. 2014. DOI: 10.5435/jaaos-22-11-718

[66] Early Recurrence of a Solid Variant of Aneurysmal Bone Cyst in a Young Child After Resection: Technique and Literature Review and Two-year Follow-up After Corpectomy. Journal of the American Academy of Orthopaedic Surgeons. 2018. DOI: 10.5435/jaaos-d-16-00315

Creative Commons BY-NC 4.0

CC Creative Commons licence
BY Attribution — you must credit the source
NC NonCommercial — not for commercial use

Attribution-NonCommercial 4.0 International

Creative Commons Corporation ("Creative Commons") is not a law firm and does not provide legal services or legal advice. Distribution of Creative Commons public licenses does not create a lawyer-client or other relationship. Creative Commons makes its licenses and related information available on an "as-is" basis. Creative Commons gives no warranties regarding its licenses, any material licensed under their terms and conditions, or any related information. Creative Commons disclaims all liability for damages resulting from their use to the fullest extent possible.

Using Creative Commons Public Licenses

Creative Commons public licenses provide a standard set of terms and conditions that creators and other rights holders may use to share original works of authorship and other material subject to copyright and certain other rights specified in the public license below. The following considerations are for informational purposes only, are not exhaustive, and do not form part of our licenses.

Considerations for licensors: Our public licenses are intended for use by those authorized to give the public permission to use material in ways otherwise restricted by copyright and certain other rights. Our licenses are irrevocable. Licensors should read and understand the terms and conditions of the license they choose before applying it. Licensors should also secure all rights necessary before applying our licenses so that the public can reuse the material as expected. Licensors should clearly mark any material not subject to the license. This includes other CC- licensed material, or material used under an exception or limitation to copyright. More considerations for licensors: wiki.creativecommons.org/Considerations_for_licensors

Considerations for the public: By using one of our public licenses, a licensor grants the public permission to use the licensed material under specified terms and conditions. If the licensor's permission is not necessary for any reason--for example, because of any applicable exception or limitation to copyright--then that use is not regulated by the license. Our licenses grant only permissions under copyright and certain other rights that a licensor has authority to grant. Use of the licensed material may still be restricted for other reasons, including because others have copyright or other rights in the material. A licensor may make special requests, such as asking that all changes be marked or described. Although not required by our licenses, you are encouraged to respect those requests where reasonable. More considerations for the public: wiki.creativecommons.org/Considerations_for_licensees

Creative Commons Attribution-NonCommercial 4.0 International Public License

By exercising the Licensed Rights (defined below), You accept and agree to be bound by the terms and conditions of this Creative Commons Attribution-NonCommercial 4.0 International Public License ("Public License"). To the extent this Public License may be interpreted as a contract, You are granted the Licensed Rights in consideration of Your acceptance of these terms and conditions, and the Licensor grants You such rights in consideration of benefits the Licensor receives from making the Licensed Material available under these terms and conditions.

Section 1 -- Definitions.

a. Adapted Material means material subject to Copyright and Similar Rights that is derived from or based upon the Licensed Material and in which the Licensed Material is translated, altered, arranged, transformed, or otherwise modified in a manner requiring permission under the Copyright and Similar Rights held by the Licensor. For purposes of this Public License, where the Licensed Material is a musical work, performance, or sound recording, Adapted Material is always produced where the Licensed Material is synched in timed relation with a moving image.

b. Adapter's License means the license You apply to Your Copyright and Similar Rights in Your contributions to Adapted Material in accordance with the terms and conditions of this Public License.

c. Copyright and Similar Rights means copyright and/or similar rights closely related to copyright including, without limitation, performance, broadcast, sound recording, and Sui Generis Database Rights, without regard to how the rights are labeled or categorized. For purposes of this Public License, the rights specified in Section 2(b)(1)-(2) are not Copyright and Similar Rights.

d. Effective Technological Measures means those measures that, in the absence of proper authority, may not be circumvented under laws fulfilling obligations under Article 11 of the WIPO Copyright Treaty adopted on December 20, 1996, and/or similar international agreements.

e. Exceptions and Limitations means fair use, fair dealing, and/or any other exception or limitation to Copyright and Similar Rights that applies to Your use of the Licensed Material.

f. Licensed Material means the artistic or literary work, database, or other material to which the Licensor applied this Public License.

g. Licensed Rights means the rights granted to You subject to the terms and conditions of this Public License, which are limited to all Copyright and Similar Rights that apply to Your use of the Licensed Material and that the Licensor has authority to license.

h. Licensor means the individual(s) or entity(ies) granting rights under this Public License.

i. NonCommercial means not primarily intended for or directed towards commercial advantage or monetary compensation. For purposes of this Public License, the exchange of the Licensed Material for other material subject to Copyright and Similar Rights by digital file-sharing or similar means is NonCommercial provided there is no payment of monetary compensation in connection with the exchange.

j. Share means to provide material to the public by any means or process that requires permission under the Licensed Rights, such as reproduction, public display, public performance, distribution, dissemination, communication, or importation, and to make material available to the public including in ways that members of the public may access the material from a place and at a time individually chosen by them.

k. Sui Generis Database Rights means rights other than copyright resulting from Directive 96/9/EC of the European Parliament and of the Council of 11 March 1996 on the legal protection of databases, as amended and/or succeeded, as well as other essentially equivalent rights anywhere in the world.

l. You means the individual or entity exercising the Licensed Rights under this Public License. Your has a corresponding meaning.

Section 2 -- Scope.

a. License grant.

1. Subject to the terms and conditions of this Public License, the Licensor hereby grants You a worldwide, royalty-free, non-sublicensable, non-exclusive, irrevocable license to exercise the Licensed Rights in the Licensed Material to:

a. reproduce and Share the Licensed Material, in whole or in part, for NonCommercial purposes only; and

b. produce, reproduce, and Share Adapted Material for NonCommercial purposes only.

2. Exceptions and Limitations. For the avoidance of doubt, where Exceptions and Limitations apply to Your use, this Public License does not apply, and You do not need to comply with its terms and conditions.

3. Term. The term of this Public License is specified in Section 6(a).

4. Media and formats; technical modifications allowed. The Licensor authorizes You to exercise the Licensed Rights in all media and formats whether now known or hereafter created, and to make technical modifications necessary to do so. The Licensor waives and/or agrees not to assert any right or authority to forbid You from making technical modifications necessary to exercise the Licensed Rights, including technical modifications necessary to circumvent Effective Technological Measures. For purposes of this Public License, simply making modifications authorized by this Section 2(a) (4) never produces Adapted Material.

5. Downstream recipients.

a. Offer from the Licensor -- Licensed Material. Every recipient of the Licensed Material automatically receives an offer from the Licensor to exercise the Licensed Rights under the terms and conditions of this Public License.

b. No downstream restrictions. You may not offer or impose any additional or different terms or conditions on, or apply any Effective Technological Measures to, the Licensed Material if doing so restricts exercise of the Licensed Rights by any recipient of the Licensed Material.

6. No endorsement. Nothing in this Public License constitutes or may be construed as permission to assert or imply that You are, or that Your use of the Licensed Material is, connected with, or sponsored, endorsed, or granted official status by, the Licensor or others designated to receive attribution as provided in Section 3(a)(1)(A)(i).

b. Other rights.

1. Moral rights, such as the right of integrity, are not licensed under this Public License, nor are publicity, privacy, and/or other similar personality rights; however, to the extent possible, the Licensor waives and/or agrees not to assert any such rights held by the Licensor to the limited extent necessary to allow You to exercise the Licensed Rights, but not otherwise.

2. Patent and trademark rights are not licensed under this Public License.

3. To the extent possible, the Licensor waives any right to collect royalties from You for the exercise of the Licensed Rights, whether directly or through a collecting society under any voluntary or waivable statutory or compulsory licensing scheme. In all other cases the Licensor expressly reserves any right to collect such royalties, including when the Licensed Material is used other than for NonCommercial purposes.

Section 3 -- License Conditions.

Your exercise of the Licensed Rights is expressly made subject to the following conditions.

a. Attribution.

1. If You Share the Licensed Material (including in modified form), You must:

a. retain the following if it is supplied by the Licensor with the Licensed Material:

i. identification of the creator(s) of the Licensed Material and any others designated to receive attribution, in any reasonable manner requested by the Licensor (including by pseudonym if designated);

ii. a copyright notice;

iii. a notice that refers to this Public License;

iv. a notice that refers to the disclaimer of warranties;

v. a URI or hyperlink to the Licensed Material to the extent reasonably practicable;

b. indicate if You modified the Licensed Material and retain an indication of any previous modifications; and

c. indicate the Licensed Material is licensed under this Public License, and include the text of, or the URI or hyperlink to, this Public License.

2. You may satisfy the conditions in Section 3(a)(1) in any reasonable manner based on the medium, means, and context in which You Share the Licensed Material. For example, it may be reasonable to satisfy the conditions by providing a URI or hyperlink to a resource that includes the required information.

3. If requested by the Licensor, You must remove any of the information required by Section 3(a)(1)(A) to the extent reasonably practicable.

4. If You Share Adapted Material You produce, the Adapter's License You apply must not prevent recipients of the Adapted Material from complying with this Public License.

Section 4 -- Sui Generis Database Rights.

Where the Licensed Rights include Sui Generis Database Rights that apply to Your use of the Licensed Material:

a. for the avoidance of doubt, Section 2(a)(1) grants You the right to extract, reuse, reproduce, and Share all or a substantial portion of the contents of the database for NonCommercial purposes only;

b. if You include all or a substantial portion of the database contents in a database in which You have Sui Generis Database Rights, then the database in which You have Sui Generis Database Rights (but not its individual contents) is Adapted Material; and

c. You must comply with the conditions in Section 3(a) if You Share all or a substantial portion of the contents of the database.

For the avoidance of doubt, this Section 4 supplements and does not replace Your obligations under this Public License where the Licensed Rights include other Copyright and Similar Rights.

Section 5 -- Disclaimer of Warranties and Limitation of Liability.

a. UNLESS OTHERWISE SEPARATELY UNDERTAKEN BY THE LICENSOR, TO THE EXTENT POSSIBLE, THE LICENSOR OFFERS THE LICENSED MATERIAL AS-IS AND AS-AVAILABLE, AND MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND CONCERNING THE LICENSED MATERIAL, WHETHER EXPRESS, IMPLIED, STATUTORY, OR OTHER. THIS INCLUDES, WITHOUT LIMITATION, WARRANTIES OF TITLE, MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT, ABSENCE OF LATENT OR OTHER DEFECTS, ACCURACY, OR THE PRESENCE OR ABSENCE OF ERRORS, WHETHER OR NOT KNOWN OR DISCOVERABLE. WHERE DISCLAIMERS OF WARRANTIES ARE NOT ALLOWED IN FULL OR IN PART, THIS DISCLAIMER MAY NOT APPLY TO YOU.

b. TO THE EXTENT POSSIBLE, IN NO EVENT WILL THE LICENSOR BE LIABLE TO YOU ON ANY LEGAL THEORY (INCLUDING, WITHOUT LIMITATION, NEGLIGENCE) OR OTHERWISE FOR ANY DIRECT, SPECIAL, INDIRECT, INCIDENTAL, CONSEQUENTIAL, PUNITIVE, EXEMPLARY, OR OTHER LOSSES, COSTS, EXPENSES, OR DAMAGES ARISING OUT OF THIS PUBLIC LICENSE OR USE OF THE LICENSED MATERIAL, EVEN IF THE LICENSOR HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH LOSSES, COSTS, EXPENSES, OR DAMAGES. WHERE A LIMITATION OF LIABILITY IS NOT ALLOWED IN FULL OR IN PART, THIS LIMITATION MAY NOT APPLY TO YOU.

c. The disclaimer of warranties and limitation of liability provided above shall be interpreted in a manner that, to the extent possible, most closely approximates an absolute disclaimer and waiver of all liability.

Section 6 -- Term and Termination.

a. This Public License applies for the term of the Copyright and Similar Rights licensed here. However, if You fail to comply with this Public License, then Your rights under this Public License terminate automatically.

b. Where Your right to use the Licensed Material has terminated under Section 6(a), it reinstates:

1. automatically as of the date the violation is cured, provided it is cured within 30 days of Your discovery of the violation; or

2. upon express reinstatement by the Licensor.

For the avoidance of doubt, this Section 6(b) does not affect any right the Licensor may have to seek remedies for Your violations of this Public License.

c. For the avoidance of doubt, the Licensor may also offer the Licensed Material under separate terms or conditions or stop distributing the Licensed Material at any time; however, doing so will not terminate this Public License.

d. Sections 1, 5, 6, 7, and 8 survive termination of this Public License.

Section 7 -- Other Terms and Conditions.

a. The Licensor shall not be bound by any additional or different terms or conditions communicated by You unless expressly agreed.

b. Any arrangements, understandings, or agreements regarding the Licensed Material not stated herein are separate from and independent of the terms and conditions of this Public License.

Section 8 -- Interpretation.

a. For the avoidance of doubt, this Public License does not, and shall not be interpreted to, reduce, limit, restrict, or impose conditions on any use of the Licensed Material that could lawfully be made without permission under this Public License.

b. To the extent possible, if any provision of this Public License is deemed unenforceable, it shall be automatically reformed to the minimum extent necessary to make it enforceable. If the provision cannot be reformed, it shall be severed from this Public License without affecting the enforceability of the remaining terms and conditions.

c. No term or condition of this Public License will be waived and no failure to comply consented to unless expressly agreed to by the Licensor.

d. Nothing in this Public License constitutes or may be interpreted as a limitation upon, or waiver of, any privileges and immunities that apply to the Licensor or You, including from the legal processes of any jurisdiction or authority.

Creative Commons is not a party to its public licenses. Notwithstanding, Creative Commons may elect to apply one of its public licenses to material it publishes and in those instances will be considered the “Licensor.” The text of the Creative Commons public licenses is dedicated to the public domain under the CC0 Public Domain Dedication. Except for the limited purpose of indicating that material is shared under a Creative Commons public license or as otherwise permitted by the Creative Commons policies published at creativecommons.org/policies, Creative Commons does not authorize the use of the trademark "Creative Commons" or any other trademark or logo of Creative Commons without its prior written consent including, without limitation, in connection with any unauthorized modifications to any of its public licenses or any other arrangements, understandings, or agreements concerning use of licensed material. For the avoidance of doubt, this paragraph does not form part of the public licenses.

Creative Commons may be contacted at creativecommons.org.