Minimally invasive resection of lumbar intraspinal synovial cysts via a contralateral approach: review of 13 cases

Outcomes and adverse events for spinal synovial cysts surgical treatment: a systematic review and meta-analysis

BACKGROUND

Spinal synovial cysts (SSCs) are a rare cause of nerve root and spinal cord compression. Surgical excision of SSCs remains the mainstay of treatment in the presence of unremitting symptoms or neurological deficits, but the choice of the surgical approach remains controversial. The goal of this study was to compare clinical outcomes and adverse events associated with traditional approaches (interlaminar or laminectomy/hemilaminectomy) and minimally invasive approaches (microsurgical tubular approaches or endoscopic approaches) for SSCs.

METHODS

Studies reporting surgical management of SSCs were searched in three online databases (PubMed, the Cochrane Library, and Web of Science). This meta-analysis was reported following the PRISMA Statement. It was registered at the International Prospective Register of Systematic Reviews (CRD42021288992). The Cochrane Collaboration's Risk of Bias in Nonrandomised Studies-of Interventions (ROBINS-I) was used to evaluate bias. Extracted research data were statistically analyzed using Stata 16 and SPSS statistics 25.

RESULTS

A total of 22 related relevant studies were included. Meta-analysis revealed no statistically significant difference in dural tear, residual cyst, recurrence, reoperation, and operation time between minimally invasive approaches and traditional approaches (p > 0.05), but minimally invasive approaches had a good functional improvement (p = 0.004). Postoperative length of hospital stays and intraoperative bleeding in traditional approaches were also higher than in minimally invasive approaches (p < 0.05).

CONCLUSION

Based on the available evidence, minimally invasive approaches may be better than traditional approaches in the treatment of SSCs. Minimally invasive approaches had the advantages of improving clinical satisfaction, with a similar complication rate to traditional approaches. Moreover, endoscopic and microsurgical tubular approaches had similar outcomes.

Efficacy of minimally invasive tubular approaches for management of the lumbar spinal synovial cysts: a meta-analysis

The treatment of lumbar spinal synovial cysts (LSCs) which are relatively rare but can cause neurogenic dysfunction and intractable pain has been a controversial topic for many years. Surgical excision of LSCs is the standard treatment for patients in whom conservative treatment options fail. This meta-analysis was undertaken to compare clinical outcomes between minimally invasive approaches using tubular retractors (microscopic vs. endoscopic) and traditional percutaneous approaches for LSCs. Studies reporting surgical management of LSCs were searched in the Cochrane Library, PubMed and Web of Science database. This meta-analysis was reported following the PRISMA Statement, registered in Prospero (CRD42021288992). A total of 1833 patients were included from both the related relevant studies (41 studies, n = 1831) and the present series (n = 2). Meta-analysis of minimally invasive tubular approaches revealed no statistically significant difference in pain improvement, dural tear, residual cyst, recurrence and operation time between minimal groups with traditional groups (p > 0.05). Minimal groups had better Functional improvement of 100% (95% CI 1.00-1.00; p < 0.001, I2 = 75.3%) and less reoperation rates of 0% (95% CI - 0.00-0.00; p = 0.007, I2 = 47.1%). Postoperative length of hospital stay and intraoperative bleeding in minimal groups were also less than traditional groups (p < 0.05). Subgroup analysis revealed endoscopic groups had less operation time (p = 0.004), and there was no significant difference in the rest. For patients with LSCs but without obvious clinical and imaging evidence of vertebral instability, even when preoperative stable grade 1 spondylolisthesis is present, minimally invasive tubular approaches without fusion may provide the best outcome in surgical management.

Awake transforaminal endoscopic lumbar facet cyst resection: technical note and case series

OBJECTIVE

The aim of this study was to describe a minimally invasive transforaminal surgical technique for treating awake patients presenting with lumbar radiculopathy and compressive facet cysts.

METHODS

Awake transforaminal endoscopic decompression surgery was performed in 645 patients over a 6-year period from 2014 to 2020. Transforaminal endoscopic decompression surgery utilizing a high-speed endoscopic drill was performed in 25 patients who had lumbar facet cysts. All surgeries were performed as outpatient procedures in awake patients. Nine of the 25 patients had previously undergone laminectomies at the treated level. A retrospective chart review of patient-reported outcome measures is presented.

RESULTS

At the 2-year follow-up, the mean (± standard deviation) preoperative visual analog scale leg score and Oswestry Disability Index improved from 7.6 ± 1.3 to 2.3 ± 1.4 and 39.7% ± 8.1% to 13.0% ± 7.4%, respectively. There were no complications, readmissions, or recurrence of symptoms during the 2-year follow-up period.

CONCLUSIONS

A minimally invasive awake procedure is presented for the treatment of lumbar facet cysts in patients with lumbar radiculopathy. Approximately one-third of the treated patients (9 of 25) had postlaminectomy facet cysts.

Minimally Invasive Surgical Decompression without Fusion for the Treatment of Lumbar Synovial Cysts: Feasibility and Long-Term Outcomes

BACKGROUND

Lumbar synovial cysts (LSCs) can cause painful radiculopathy and sensory and/or motor deficits. Historically, first-line surgical treatment has been decompression with fusion. Recently, minimally invasive laminectomy without fusion has shown equal or superior results to traditional decompression and fusion methods.

OBJECTIVE

This study investigates the long-term efficacy of minimally invasive laminectomy without fusion in the treatment of LSC as it relates to the rate of subsequent fusion surgery.

METHODS

A retrospective review was performed over a 10-year period of patients undergoing minimally invasive laminectomy for symptomatic LSCs. The primary end point was the rate of revision surgery requiring fusion.

RESULTS

Eighty-five patients with symptomatic LSCs underwent minimally invasive laminectomy alone January 2010-August 2020 at our institution. The most common location was L4-5 (72%). Preoperative imaging identified spondylolisthesis (grade 1) in 43 patients (57%), none of which was unstable on available dynamic radiographs. Average procedure duration was 93 minutes, with 78% of patients discharged home on the same day of surgery. Over 46 months of mean follow-up, 17 patients (20%) required 19 revision operations. Of those operations, 16 were spinal fusions (17.6%). Median time to fusion surgery was 36 months. There were no identifiable risk factors on multivariate regression analysis that predicted the need for fusion.

CONCLUSIONS

Minimally invasive laminectomy is an effective first-line treatment for symptomatic LSCs and avoids the need for fusion in most treated patients. Of our patients, 18% required a fusion over 46 months, suggesting that further studies are required to guide patient selection.

Five-Year Outcomes After Decompression and Fusion Versus Decompression Alone in the Treatment of Lumbar Synovial Cysts

BACKGROUND

Spinal synovial cysts are acquired, fluid-filled lesions of the facet joint that most commonly occur in the lumbar spine. They are thought to arise from degenerative changes and to result from segmental instability. Although the treatment of these lesions has been studied, the long-term implications and effects of the different strategies for surgical intervention (i.e., decompression and fusion vs. decompression alone) have not yet been elucidated or established.

METHODS

Using an all-payer database with 53 million patient records (MARINER-53), patients with a diagnosis of lumbar synovial cysts were identified. Patients who had undergone lumbar fusion versus laminectomy were matched 1:1 using binomial and gaussian logistic regression models to evaluate the need for future lumbar surgery within 5 years after their index procedure.

RESULTS

No statistically significant differences were noted between the 5-year rates of subsequent intervention, additional laminectomy, or fusion among patients who had undergone index decompression and fusion (n = 51; 10.5%) versus decompression alone (n = 43; 8.8%; P = 0.39). Furthermore, no significant differences were found in the odds of intervention type after index decompression and fusion versus decompression alone (subsequent laminectomy: odds ratio, 0.59; 95% confidence interval, 0.32-1.09; subsequent fusion: odds ratio, 1.14; 95% confidence interval, 0.64-2.02).

CONCLUSIONS

Patient-specific factors and surgeon-patient-shared decision-making should be used when planning interventions for these lesions. However, synovial cysts might not require a fusion procedure for presumed instability. Further investigation is required, using randomized and prospective studies, to further evaluate the effective treatment of this entity.

The Contralateral Approach to intra- and Extraforaminal Lumbar Disk Herniations: Surgical Technique and Review of Surgical Procedures

BACKGROUND

 Surgery for intra-/extraforaminal disk herniations (IEDH) is technically demanding due to the hidden location of the compressed nerve root section. Ipsilateral approaches (medial and lateral) are accompanied by extended resection of the facet joint and inadequate visualization of the pathology, especially at the L5-S1 level.

METHODS

 We describe a microsurgical interlaminar contralateral approach (MICA) suitable for IEDH at the lumbosacral junction that can also be used at L4-L5 and L3-L4.

CONCLUSION

 The MICA provides access and sufficient intraforaminal visualization for IEDH in the lumbosacral region without resection of stability-relevant structures or manipulation of the nerve root ganglion.

Minimally Invasive Posterior Tubular Microsurgical Approach for the Management of Symptomatic Synovial Cysts of the Lumbar and Cervical Spine

BACKGROUND

Synovial cysts are commonly associated with instability. Whether to fuse patients is a matter of controversy. Simple resection may offer favorable clinical outcomes but may come at the expense of recurrence rate. We describe our experience with the minimally invasive management of these lesions using microsurgical dissection through a tubular retractor system.

MATERIALS

A retrospective cohort study of symptomatic patients with synovial cysts treated by a minimally invasive tubular approach from 2001 to 2018 was performed. We evaluated variables such as preexisting spinal pathology, previous surgery, radiological findings, comorbidities, and secondary surgery requiring fusion. We used the visual analog scale (VAS), the Oswestry disability index (ODI), and the Macnab scale for clinical evaluation.

RESULTS

There were 35 patients with a mean age of 63 years. The mean duration of symptoms before surgery was 195 weeks. Axial pain was present in 77.1% of cases; radiculopathy was the main symptom in 94.3% of cases. The most frequent site was L4-L5 (62.8%). Presenting comorbidities were lumbar stenosis (28.6% of patients), spondylolisthesis (8.6%), and facet hypertrophy (31.4%). Mean surgical time was 143 minutes (range, 55-360 minutes). The mean hospital stay was 2 days, ranging from 1 to 5 days. No complications were encountered as a consequence of the surgical procedure. All patients showed neurophysiological improvement after surgical intervention. A total of 34 patients (97.14%) showed clinical improvement at the end of follow-up, averaging 17 months and ranging from 1 to 60 months, 28 patients (80%) had good to excellent Macnab outcomes, 6 patients (17.14%) were rated as fair, and 1 (2.86%) patient had a poor Macnab outcome. Radicular VAS significantly changed (P < .05) from a preoperative mean of 8.23 ± 1.24 to a postoperative mean of 2.23 ± 1.94. ODI significantly decreased (P < .05) from a preoperative of mean of 41.02 ± 12.56 to a postoperative of mean of 11.82 ± 10.56. We performed fusion at initial surgery in 37.1% of cases; however, 3 more patients required secondary fusion at follow-up.

CONCLUSION

Our series corroborates the prior literature with a low incidence of synovial cysts in the cervical spine and none in the thoracic spine. The present work shows the efficacy of minimally invasive surgery in the treatment of these lesions. Synovial cysts were associated with instability, ultimately requiring fusion in the majority of patients. The authors' study includes a large patient series with minimally invasive microsurgical decompression performed through a tubular retractor to date.

LEVEL OF EVIDENCE

3.

Outcomes and complications following minimally invasive excision of synovial cysts of the lumbar spine: A systematic review and meta-analysis

OBJECTIVE

Lumbar synovial cysts (LSC) are one of the manifestations of spinal degenerative cascade. Spinal stenosis or presence of instability in these patients can lead to various symptoms and surgery is indicated following failure of non-operative management for symptomatic synovial cysts. Surgery when performed consists of either decompression with resection of cyst with our without fusion. The efficacy and complications of minimally invasive techniques using tubular retractors (microscopic or endoscopic) in comparison to traditional open techniques remain to be studied.

METHODS

A comprehensive search of different databases was performed to retrieve studies describing the use of minimal invasive techniques using tubular retractors (both microscopic and endoscopic) in patients with LSC. Meta-analysis with subgroup analysis and metaregression was done.

RESULTS

Twenty articles were selected for the systematic review and meta-analysis with total of 388 patients. Eighty-six percent of patients (95% Confidence Interval (CI): 80-90%) had favorable outcome as per Macnab's criteria (excellent and good outcome) with the pooled standard mean difference between preoperative and postoperative Oswestry Disability Index (ODI) being -4.44 (95% CI -8.78 to -0.10, p-value=0.0474, I² 82%). The pooled percentage change in visual analogue scale (VAS) after surgery was 76.5% (95% CI 66.9-84%, I² 82%). The pooled proportion of incidental durotomies, cyst recurrence and patients requiring operation being 8% (95% CI 5-11%, I² 0%), 4% (95% CI 2-7%, I² 0%,) and 5% (95% CI 3-9%) respectively. Studies were homogeneous with an I² value of 0%. Subgroup analysis revealed no significant difference in the outcome rates or complication rates between the microscopic and endoscopic subgroups.

CONCLUSION

Minimally invasive techniques for the resection of LSC is a safe and effective alternative to traditional surgical approaches with no difference between the microscopic and endoscopic approaches.

Mini-Tubular Access Surgery: A Single Surgeon's 12 Years in the Corridors of the Neuroaxis

BACKGROUND

 Tubular approach surgery now includes complex spinal and cranial procedures. Aided by modified instrumentation and frameless stereotaxy, minimal access surgery is being offered for a growing array of neurosurgical conditions.

METHODS

 This article explores the flexibility and adaptability of the tubular retractor system for multiple indications by highlighting the 12-year experience of the primary surgeon using a tubular retractor system reported for the entire neuroaxis including intracranial, foramen magnum, and the craniocaudal extent of the spine for intra- and extradural pathologies. For this article we have not analyzed our experience with degenerative spinal disease. Patient characteristics, pathology, resection results, length of hospital stay, and complications are discussed.

RESULTS

 From August 2005 through March 2017, 538 patients underwent neurosurgical procedures with mini-tubular access. Of these, the 127 patients who underwent mini-tubular access operations for nontraditional indications are discussed here. There were 65 women and 61 men with an average age of 53.5 years. The cases by anatomical location are as follows: 27 cranial cases, 11 foramen magnum decompressions, and 89 for spinal indications. The cranial pathologies included primary and metastatic tumors. The spinal pathologies included intra- and extradural spinal tumors, spina bifida occulta, syringomyelia, and other cystic lesions in the spine. In the vast majority of the patients where gross total resection was the goal, it was achieved. The mean length of stay was 2.94 days.

CONCLUSIONS

 This report demonstrates that mini-tubular access surgery can be adapted to pathologies in the entire neuroaxis with outcomes that are comparable with open techniques. Limited tissue dissection, smaller incisions, and limited bone resection make the mini-tubular access approach a desirable option when feasible. Greater experience with all of these techniques is needed before the definitive status of these procedures in the neurosurgical armamentarium can be demonstrated.

Transdural Approach to Resection of Intraspinal Extradural Ventral Cysts in the Lumbar Spine

BACKGROUND

Intraspinal extradural ventral cysts in the lumbar spine can cause back pain and neurological deficits of the lower extremities. For the resection of this type of space-occupying lesion, the transdural approach has not been reported in the literature.

CASE DESCRIPTION

A 66-year-old man presented, suffering from progressive radiation pain of his bilateral lower extremities. Imaging examination revealed a cystic lesion in ventral side of lumbar spinal canal. We conducted the excision of the cyst with the transdural approach. The symptoms of the patient disappeared immediately after the operation and recurrence of the symptoms has not been observed in the 3-month follow-up.

CONCLUSIONS

This operation approach is safe and effective. Compared with the previous surgical approach reported in the literature, by this approach surgeons could achieve less injury, shorter operation time, and the same surgical outcomes in the short term. Therefore, we would like to present this approach to provide an alternative to deal with similar lesions.

[Minimally invasive resection of spinal synovial cysts: Technical note]

Objetivo:

Presentar el algoritmo de tratamiento, técnica quirúrgica y resultados de una serie de pacientes con quistes sinoviales espinales resecados con técnica mínimamente invasiva (MIS).

Introducción:

Los quistes sinoviales espinales se originan a partir de la dilatación y potencial ruptura de la vaina sinovial de una articulación facetaria, la resección quirúrgica es considerada el tratamiento de elección en pacientes sintomáticos. La utilización de técnicas MIS podrían disminuir la disrupción de la faceta articular comprometida reduciendo el riesgo de inestabilidad postoperatoria.

Material y métodos:

Se evaluaron retrospectivamente 21 pacientes con quistes sinoviales espinales operados mediante abordaje y descompresión MIS, se analizaron los signos, síntomas, tiempo quirúrgico, estadía hospitalaria, evolución y complicaciones. Se utilizó la escala visual analógica (EVA), para evaluar el dolor y la escala de Weiner y los criterios de Macnab modificados para medir la satisfacción posoperatoria del paciente.

Resultados:

Se trataron quirúrgicamente 21 pacientes (13 mujeres, 8 hombres), el 76,2% (n = 16) de los pacientes de la serie no requirió artrodesis, el 23,8% (n = 5) restante fue fusionado. Realizamos 13 (61,9%) hemilaminectomías contralaterales, 7 hemilaminectomías ipsilaterales (33,3%) y una laminectomía en el QS S1-S2 con técnica MIS. El seguimiento promedio fue de 26 meses, el tiempo de cirugía fue de 150,33 ± 63,31 min., con una estadía hospitalaria de 2,5 ± 1,78 días. La EVA disminuyó de 8,3 preoperatoria a 2,3 postoperatoria. Siguiendo la escala de Macnab; 16 pacientes refirieron resultados excelentes, 4 buenos y 1 regular, el 95,2% de los pacientes percibió que el procedimiento tuvo mucho/bastante éxito según la escala de Weiner.

Conclusión:

El abordaje mínimamente invasivo es un procedimiento seguro y eficaz para la resección completa de quistes sinoviales espinales. Proporciona resultados clínico-funcionales excelentes preservando músculos, ligamentos y facetas articulares.

Spinal synovial cysts. A case series and current treatment options

Synovial cysts constitute an uncommon degenerative lesion of the spine. They are usually asymptomatic but they may also cause symptoms of variable severity. The authors present three cases of such cysts, two in the lumbar region of a 55-year-old female and a 66 year old female and one in the cervical region of a 56-year-old male patient. All patients presented with radiculopathy. Magnetic Resonance Images revealed a cystic lesion at the L4/5 level in the first case, at L5/S1 level in the second case and at the C7/T1 junction level in the third case. Treatment has been microsurgical resection of all cysts with no post-operative complications and an excellent outcome. A discussion of current management options for this unusual disease is presented and a decision making flow chart is proposed.

Synovial cysts of the spine: long-term follow-up after surgical treatment of 141 cases in a single-center series and comprehensive literature review of 2900 degenerative spinal cysts

OBJECTIVE Synovial cysts of the spine are rare lesions, predominantly arising in the lumbar region. Despite their generally benign behavior, they can cause severe symptoms due to compression of neural structures in the spinal canal. Treatment strategies are still a matter of discussion. The authors performed a single-center survey and literature search focusing on long-term results after minimally invasive surgery. METHODS A total of 141 consecutive patients treated for synovial cysts of the lumbar spine between 1997 and 2014 in the authors' department were analyzed. Medical reports with regard to signs and symptoms, operative findings, complications, and short-term outcome were reviewed. Assessment of long-term outcome was performed with a standardized telephone questionnaire based on the Oswestry Disability Index (ODI). Furthermore, patients were questioned about persisting pain, symptoms, and further operative procedures, if any. Subjective satisfaction was classified as excellent, good, fair, or poor based on the Macnab classification. RESULTS The approach most often used for synovial cyst treatment was partial hemilaminectomy in 70%; hemilaminectomy was necessary in 27%. At short-term follow-up, the presence of severe and moderate leg pain had decreased from 93% to 5%. The presence of low-back pain decreased from 90% to 5%. Rates of motor and sensory deficits were reduced from 40% to 14% and from 45% to 6%, respectively. The follow-up rate was 58%, and the mean follow-up period was 9.3 years. Both leg pain and low-back pain were still absent in 78%. Outcome based on the Macnab classification was excellent in 80%, good in 14%, fair in 1%, and poor in 5%. According to the ODI, 78% of patients had no or only minimal disability, 16% had moderate disability, and 6% had severe disability at the time of follow-up. In this cohort, 7% needed surgery due to cyst recurrence, and 9% required a delayed stabilization procedure after the initial operation. CONCLUSIONS Surgical treatment with resection of the cyst provides favorable results in outcome. Excellent or good outcome persisting for a long-term follow-up period can be achieved in the vast majority of cases. Complication rates are low despite an increased risk of dural injury. With facet-sparing techniques, the stability of the segment can be preserved, and resection of spinal synovial cysts does not necessarily require segmental fusion.

Contralateral Approach for Minimally Invasive Treatment of Upper Lumbar Intervertebral Disc Herniation: Technical Note and Case Series

BACKGROUND

Upper lumbar disc herniations comprise only 1%-2% of all lumbar disc herniations. Patients exhibit nonspecific signs and symptoms in comparison to predictable radiculopathies, as seen in lower lumbar disc herniations. The unique anatomic characteristics of the upper lumbar spine present several challenges for safe and effective surgical treatment of disc herniations. The authors review the anatomy of the upper lumbar spine, describe a novel approach to upper lumbar disc herniations, and present 3 cases with a focus on clinical outcome and technical pearls.

METHODS

Conventional techniques for upper lumbar discectomy require a near complete facetectomy and pars interarticularis resection for adequate bony exposure, possibly leading to spinal destabilization. A tubular retractor system was used to approach upper lumbar disc herniation using a contralateral minimally invasive technique, while completely preserving the facet complex and pars interarticularis.

RESULTS

We report 3 cases of minimally invasive discectomy from a contralateral approach. The patients experienced complete resolution of presenting symptoms, and the facet complexes were preserved. All cases were free of complications.

CONCLUSION

A contralateral approach to perform a minimally invasive discectomy for paracentral and central upper LDH is a safe, efficient, and effective technique. The approach that we describe in this study preserves the facet complex and may prevent future spinal instability.

Minimally invasive surgery for lumbar synovial cysts with coexisting degenerative spondylolisthesis

BACKGROUND

About one third of lumbar synovial cysts are associated with degenerative spondylolisthesis. Segmental instability is thought to contribute to the pathogenesis and recurrence of synovial cysts and lumbar fusion has been advocated as a treatment of choice in the presence of spondylolisthesis. In patients with spondylolisthesis, minimally invasive resection of lumbar synovial cysts, without fusion, could minimize surgically induced segmental instability while providing good pain relief.

METHODS

Clinical and radiological outcomes of lumbar synovial cyst patients with and without spondylolisthesis were retrospectively compared. Pain outcomes were assessed with modified Macnab criteria.

RESULTS

Fifty-three patients (18 with grade 1 spondylolisthesis) underwent minimally invasive synovial cyst resection and all had either excellent or good pain outcome at ≤ 8 post- operative weeks (P = 1.000, n = 53). At > 8 post-operative weeks (mean (SD) follow-up of 200 (175) weeks), excellent or good outcomes were noted in 89% of patients without spondylolisthesis and in 75% of patients with spondylolisthesis (P = 0.425, n = 40). Four patients developed a new grade 1 spondylolisthesis at a mean follow-up of 2.6 ± 2.1 years. Nine patients were assessed for spondylolisthesis measurements at 1.2 ± 1.3 years of follow up and no significant difference was observed (5 ± 0 vs 5 ± 1 mm; P = 0.791). Two patients without spondylolisthesis and none of the patients with spondylolisthesis had a synovial cyst recurrence.

CONCLUSION

Patients with concomitant lumbar degenerative spondylolisthesis and synovial cyst can have good short- and long-term clinical outcomes with minimally invasive surgery without fusion. Post-operative segmental instability does not appear to be significant in patients with spondylolisthesis. All patients included in this article signed an informed consent for the use of their medical information for research.

[SENDS criteria from the diversification of MAST procedures. Implementation of preoperative simulation]

CLINICAL ISSUE

Minimal access spinal technologies (MAST) lead to a diversification of surgical procedures, which requires careful selection of the procedure and outcome monitoring. For a rational selection of the procedure simulation, endoscopy, navigation, decompression and stabilization (SENDS) criteria can be derived from the development of the MAST procedures. Preoperative simulation has diagnostic and therapeutic values. The SENDS criteria can be verified indirectly via outcome control.

STANDARD TREATMENT

Biomechanically meaningful diagnostic x-rays of the spinal segment to be surgically treated are currently carried out with the patient in inclination and reclination.

TREATMENT INNOVATIONS

Software-related preoperative simulation based on these x-ray images facilitates the selection and implementation of the MAST procedure.

DIAGNOSTIC WORK-UP

For preoperative simulation motion shots are needed in inclination, neutral position and reclination and the dimensions can be obtained using an x-ray ball or a computed tomography (CT) scan.

PERFORMANCE

The SENDS criteria are useful because established procedures based on these criteria reach a comparable outcome. Preoperative simulation appears to be a useful selection criterion.

ACHIEVEMENTS

Preoperatively it is necessary to collate patient and segment information in order to provide each patient with individualized treatment. So far there is no evidence for a better outcome after preoperative simulation but a reduction of surgery time and intraoperative radiation exposure could already be demonstrated.

PRACTICAL RECOMMENDATIONS

Minimally invasive methods should be preferred if there is a comparable outcome. The establishment of new procedures has to be accompanied by the maintenance of a spine register. Minimally invasive surgical procedures should be individualized for each patient and segment. Mobility X-ray images should be prepared for use with the preoperative simulation as the information content significantly increases with respect to the MAST procedure.