Minimal access spinal technologies: state-of-the-art, indications, and techniques

Open Versus Percutaneous Stabilization of Thoracolumbar Fractures: A Large Retrospective Analysis of Safety and Reoperation Rates

BACKGROUND

Thoracolumbar fractures (TLF) requiring surgical intervention can be treated with either open or percutaneous stabilization, each with some distinct risks and benefits. There is insufficient evidence available to support one approach as superior.

METHODS

Patients who underwent spinal fixation for TLF between 2008 and 2020 were reviewed. Patients with one or two levels of fracture treated with either open or percutaneous stabilization were included. Exclusion criteria were more than two levels of fracture, patients requiring corpectomy, stabilization constructs that crossed the cervicothoracic or lumbosacral junction, history of previous thoracolumbar fusion at the same level, spinal neoplasm, anterior or lateral fixation, and spinal infection. Demographic, operative, and clinical data were collected for all patients.

RESULTS

691 patients (377 open, 314 percutaneous) met the inclusion criteria. Patients in the percutaneous cohort sustained lower estimated blood loss (73 vs 334 ml; p< 0.001) and shorter length of surgery (114 vs. 151 minutes; p< 0.001). No differences were observed in the length of hospital stay or overall reoperation rates. Asymptomatic (7.0% vs 0.8%) and symptomatic (3.5% vs 0.5%) hardware removal was more common with the percutaneous cohort, while the incidence of revision surgery due to hardware failure requiring the extension of the construct (1.9% vs 5.8%) and infection (1.9% vs 6.4%) was greater in the open group.

CONCLUSION

Percutaneous stabilization for TLF was associated with shorter operative time, less blood loss, lower infection rate, higher rates of elective hardware removal, and lower rates of hardware failure requiring extension of the construct compared to open stabilization.

Fully Endoscopic Spine Separation Surgery in Metastatic Disease-Case Series, Technical Notes, and Preliminary Findings

Objective: This report aims to describe the surgical methodology and potential effectiveness of endoscopic separation surgery (ESS) in patients with metastatic spine disease. This concept may reduce the invasiveness of the procedure, which can potentially speed up the wound healing process and, thus, the possibility of faster application of radiotherapy. Materials and Methods: In this study, separation surgery for preparing patients for stereotactic body radiotherapy (SBRT) was performed with fully endoscopic spine surgery (FESS) followed by percutaneous screw fixation (PSF). Results: Three patients with metastatic spine disease in the thoracic spine were treated with fully endoscopic spine separation surgery. The first case resulted in the progression of paresis symptoms that resulted in disqualification from further oncological treatment. The remaining two patients achieved satisfactory clinical and radiological effects and were referred for additional radiotherapy. Conclusions: With advancements in medical technology, such as endoscopic visualization, and new tools for coagulation, we can treat more and more spine diseases. Until now, spine metastasis was not an indication for the use of endoscopy. This method is very technically challenging and risky, especially at such an early stage of application, due to variations in the patient's condition, morphological diversity, and the nature of metastatic lesions in the spine. Further trials are needed to determine whether this new approach to treating patients with spine metastases is a promising breakthrough or a dead end.

Surgical management of thoracolumbar junction fractures: An evidence-based algorithm

Background

The management of thoracolumbar junction (TLJ) fractures, involving the restoring anatomical stability and biomechanics properties, still remains a challenge for neurosurgeons.Despite the high frequency of these injuries, specific treatment guidelines, set on biomechanical properties, have not yet been assumed. The present study is meant to propose an evidence-based treatment algorithm. The primary aim for the protocol validation was the assessment of postoperative neurological recovery. The secondary objectives concerned the evaluation of residual deformity and rate of hardware failure. Technical nuances of surgical approaches and drawbacks were further discussed.

Methods

Clinical and biomechanical data of patients harboring a single TLJ fracture, surgically managed between 2015 and 2020, were collected. Patients' cohorts were ranked into 4 groups according to Magerl's Type, McCormack Score, Vaccaro PLC point, Canal encroachment, and Farcy Sagittal Index. The outcome measures were the early/late Benzel-Larson Grade and postoperative kyphosis degree to estimate neurological status and residual deformity, respectively.

Results

32 patients were retrieved, 7, 9, 8, and 8 included within group 1, 2, 3, and 4, respectively. Overall neurological outcomes significantly improved for all patients at every follow-up stage (p ​< ​0.0001). Surgeries gained a complete restoration of post-traumatic kyphosis in the entire cohort (p ​< ​0.0001), except for group 4 which experienced a later worsening of residual deformity.

Conclusions

The choice of the most appropriate surgical approach for TLJ fractures is dictated by morphological and biomechanical characteristics of fracture and the grade of neurological involvement. The proposed surgical management protocol was reliable and effective, although further validations are needed.

Efficacy of a novel percutaneous pedicle screw fixation and vertebral reconstruction versus the traditional open pedicle screw fixation in the treatment of single-level thoracolumbar fracture without neurologic deficit

Objective

The aim of this study was to compare the efficacy and safety of a novel percutaneous pedicle screw fixation and vertebral reconstruction (PPSR) vs. that of open pedicle screw fixation (OPSF) in the treatment of thoracolumbar fractures.

Methods

This retrospective study enrolled 153 patients who underwent PPSR and 176 patients who received OPSF. Periprocedural characteristics, radiographic parameters, and clinical outcomes were compared between the two groups.

Results

The operation duration was 93.843 ± 20.611 in PPSR group and 109.432 ± 11.903 in OPSF group; blood loss was 131.118 ± 23.673 in PPSR group and 442.163 ± 149.701 in OPSF group, incision length was 7.280 ± 1.289 in PPSR group and 14.527 ± 2.893 in OPSF group, postoperative stay was 8.732 ± 1.864 in PPSR group and 15.102 ± 2.117 in OPSF group, and total hospitalization costs were 59027.196 ± 8687.447 in PPSR group and 73144.432 ± 11747.567 in OPSF group. These results indicated that these parameters were significantly lower in PPSR compared with those in OPSF group. No significant difference was observed in the incidence of complications between the two groups. The radiographic parameters including height of the anterior vertebra, Cobb angle, and vertebral wedge angle were better in PPSR group than in OPSF group. Recovery rate of AVH was 0.449 ± 0.079 in PPSR group and 0.279 ± 0.088 in OPSF group. Analysis of clinical results revealed that during postoperative period, the VAS and ODI scores in PPSR group were lower than those in OPSF group.

Conclusions

Collectively, these results indicated that PPSR more effectively restored the height of anterior vertebra and alleviated local kyphosis compared with OPSF. Moreover, the VAS and ODI scores in PPSR group were better than those of OPSF group.

Percutaneous pedicle screw fixation without arthrodesis of 368 thoracolumbar fractures: long-term clinical and radiological outcomes in a single institution

PURPOSE

Traumatic thoracolumbar (TL) fractures are the most common vertebral fractures. Although a consensus on the preferred treatment is missing, percutaneous pedicle screw fixation (PPSF) has been progressively accepted as treatment option, since it is related to lower soft tissues surgical-injury and perioperative complications rate. This study aims to evaluate the long-term clinical-radiological outcomes after PPSF for TL fractures at a single tertiary academic hospital.

METHODS

This is a retrospective cohort study. Back pain was obtained at preoperative, postoperative and final follow-up using Visual Analog Scale. Patient-reported outcomes, the Oswestry Disability Index and the 36-Item Short Form, were obtained to asses disability during follow-up. Radiological measures included Cobb angle, mid-sagittal index, sagittal index (SI) and vertebral body height loss. A multivariate regression analysis on preoperative radiological features was performed to investigate independent risk factors for implant failure.

RESULTS

A total of 296 patients with 368 TL fractures met inclusion criteria. Mean follow-up was 124.3 months. The clinical and radiological parameters significantly improved from preoperative to last follow-up measurements. The multivariate analysis showed that Cobb angle (OR = 1.3, p < 0.001), SI (OR = 1.5, p < 0.001) and number of fractures (OR = 1.1, p = 0.05), were independent risk factors for implant failure. The overall complication rate was 5.1%, while the reoperation rate for implant failure was 3.4%.

CONCLUSIONS

In our case series, PPSF for TL injuries demonstrated good long-term clinical-radiological outcomes, along with low complication and reoperation rates. Accordingly, PPSF could be considered as a valuable treatment option for neurologically intact patients with TL fractures. Additionally, in this cohort, number of fractures ≥ 2, Cobb angle ≥ 15° and sagittal index ≥ 21° were independent risk factors for implant failure.

One-Year Clinical Outcomes of Minimal-Invasive Dorsal Percutaneous Fixation of Thoracolumbar Spine Fractures

Introduction: Minimal-invasive instrumentation techniques have become a workhorse in spine surgery and require constant clinical evaluations. We sought to analyze patient-reported outcome measures (PROMs) and clinicopathological characteristics of thoracolumbar fracture stabilizations utilizing a minimal-invasive percutaneous dorsal screw-rod system. Methods: We included all patients with thoracolumbar spine fractures who underwent minimal-invasive percutaneous spine stabilization in our clinics since inception and who have at least 1 year of follow-up data. Clinical characteristics (length of hospital stay (LOS), operation time (OT), and complications), PROMs (preoperative (pre-op), 3-weeks postoperative (post-op), 1-year postoperative: eq5D, COMI, ODI, NRS back pain), and laboratory markers (leucocytes, c-reactive protein (CRP)) were analyzed, finding significant associations between these study variables and PROMs. Results: A total of 68 patients (m: 45.6%; f: 54.4%; mean age: 76.9 ± 13.9) were included. The most common fracture types according to the AO classification were A3 (40.3%) and A4 (40.3%), followed by B2 (7.46%) and B1 (5.97%). The Median American Society of Anesthesiologists (ASA) score was 3 (range: 1−4). Stabilized levels ranged from TH4 to L5 (mean number of targeted levels: 4.25 ± 1.4), with TH10-L2 (12/68) and TH11-L3 (11/68) being the most frequent site of surgery. Mean OT and LOS were 92.2 ± 28.2 min and 14.3 ± 6.9 days, respectively. We observed 9/68 complications (13.2%), mostly involving screw misalignments and loosening. CRP increased from 24.9 ± 33.3 pre-op to 34.8 ± 29.9 post-op (p < 0.001), whereas leucocyte counts remained stable. All PROMs showed a marked significant improvement for both 3-week and 1-year evaluations compared to the preoperative situation. Interestingly, we did not find an impact of OT, LOS, lab markers, complications, and other clinical characteristics on PROMs. Notably, a higher number of stabilized levels did not affect PROMs. Conclusions: Minimal-invasive stabilization of thoracolumbar fractures utilizing a dorsal percutaneous approach resulted in significant PROM outcome improvements, although we observed a complication rate of 13.2% for up to 1 year of follow-up. PROMs were not significantly associated with clinicopathological characteristics, technique-related variables, or the number of targeted levels.

Risk Factors for Postoperative Loss of Correction in Thoracolumbar Injuries Caused by High-Energy Trauma Treated via Percutaneous Posterior Stabilization without Bone Fusion

Background and Objectives: Percutaneous pedicle screws were first introduced in 2001, soon becoming the cornerstone of minimally invasive spinal stabilization. Use of the procedure allowed adequate reduction and stabilization of spinal injuries, even in severely injured patients. This decreased bleeding and shortened surgical time, thereby optimizing outcomes; however, postoperative correction loss and kyphosis still occurred in some cases. Thus, we investigated cases of percutaneous posterior fixation for thoracolumbar injury and examined the factors affecting the loss of correction. Materials and Methods: Sixty-seven patients who had undergone percutaneous posterior fixation for thoracolumbar injury (AO classifications A3, A4, B, and C) between 2009 and 2016 were included. Patients with a local kyphosis angle difference ≥10° on computed tomography at the postoperative follow-up (over 12 months after surgery) or those requiring additional surgery for interbody fusion were included in the correction loss group (n = 23); the no-loss group (n = 44) served as the control. The degree of injury (injury level, AO classification, load-sharing score, local kyphosis angle, cuneiform deformity angle, and cranial and caudal disc injury) and surgical content (number of fixed intervertebral vertebrae, type of screw used, presence/absence of screw insertion into the injured vertebrae, and presence/absence of vertebral formation) were evaluated as factors of correctional loss and compared between the two groups. Results: Comparison between each group revealed that differences in the wedge-shaped deformation angle, load-sharing score, degree of cranial disc damage, AO classification at the time of injury, and use of polyaxial screws were statistically significant. Logistic regression analysis showed that the differences in wedge-shaped deformation angle, AO classification, and cranial disc injury were statistically significant; no other factors with statistically significant differences were found. Conclusion: Correction loss was seen in cases with damage to the cranial intervertebral disc as well as the vertebral body.

Does cage position affect the risk of cage subsidence after oblique lumbar interbody fusion in the osteoporotic lumbar spine: a finite element analysis

OBJECTIVE

This study aimed to evaluate the biomechanical effects of different cage positions with stand-alone (SA) methods and bilateral pedicle screw fixation (BPSF) in the osteoporotic lumbar spine after OLIF.

METHODS

A finite element (FE) model of an intact L3-L5 lumbar spine was constructed. After validation, an osteoporosis model (OP) was constructed by assigning osteoporotic material properties. SA models (SA1, SA2, SA3) and BPSF models (BPSF1, BPSF2, BPSF3) in which a cage was placed in the anterior, middle and posterior third of the L5 superior endplate (SEP) were constructed at the L4-L5 segment of the OP. The L4-L5 range of motion (ROM), the stress of the L5 SEP, the stress of the cage and the stress of fixation were compared among the different models.

RESULTS

According to the degree of ROM of L4-L5, the stress of the L5 SEP and the stress of the cage for most physiological motions, the SA and BPSF models were ranked as follows: SA2＜SA1＜SA3, BPSF2＜BPSF1＜BPSF3. In BPSF2, the stress of fixation was minimal in most motions. At the same cage position, the ROM of L4-L5, the stress of the L5 SEP and the stress of the cage in the BPSF models were significantly reduced compared with those in SA models; compared with SA2, BPSF2 had a maximum reduction of 83.24%, 70.71% and 73.52% in these parameters, respectively.results CONCLUSIONS: Placing the cage in the middle third of the L5 SEP for OLIF could reduce the maximum stresses of the L5 SEP, the cage and the fixation, which may reduce the risk of postoperative cage subsidence, endplate collapse and fixation fracture in the osteoporotic lumbar spine. Compared with SA OLIF, BPSF could provide sufficient stability for the surgical segment and may reduce the incidence of the aforementioned complications.

Surgical Techniques for Thoracolumbar Spine Fractures: WFNS Spine Committee Recommendations

To formulate the specific guidelines for the recommendation of thoracolumbar fracture regarding surgical techniques and nonfusion surgery. WFNS (World Federation of Neurosurgical Societies) Spine Committee organized 2 consensus meeting. For nonfusion surgery and thoracolumbar fracture, a systematic literature search in PubMed and Google Scholar database was done from 2010 to 2020. The search was further refined by excluding the articles which were duplicate, not in English or were based on animal or cadaveric subjects. After thorough shortlisting, only 50 articles were selected for full review in this consensus meeting. To generate a consensus, the levels of agreement or disagreement on each item were voted independently in a blind fashion through a Likert-type scale from 1 to 5. The consensus was achieved when the sum for disagreement or agreement was ≥ 66%. Each consensus point was clearly defined with evidence strength, recommendation grade, and consensus level provided. A magnitude of prospective papers were analyzed to formulate consensus on various surgical techniques that can be employed to address different types of thoracolumbar fractures. Surgical treatment of thoracolumbar fractures can be a better option over the nonoperative approach, especially for those who cannot tolerate months in an orthosis or cast, such as those with multiple extremity injuries, skin lesions, obesity, and so forth. It generally allows early mobilization, less hospital stay, reduced pulmonary complications, and better correction of sagittal balance. Current available literature fails to demonstrate any statistically significant benefit of fusion surgery over nonfusion in thoracolumbar fractures.

Single-center outcomes for percutaneous pedicle screw fixation in metastatic spinal lesions: can spontaneous facet fusion occur?

OBJECTIVE

Survival of cancer patients continues to improve with systemic treatment advancements, leading to an increase in cancer-related complications such as pathological spinal fractures. In this study, the authors aimed to evaluate the outcome of percutaneous stabilization with cement augmentation of the pedicle screws in the management of patients with metastatic cancer to the spine.

METHODS

The authors reviewed a retrospective case series of 74 patients with symptomatic pathological spine fractures treated with cement-augmented pedicle screws implanted with a percutaneous technique. The mean imaging follow-up was 11.3 months. Data on demographics, clinical outcomes, and complications were collected. Cement extravasation, spinal hardware integrity, and fusion rates were assessed on CT scans.

RESULTS

Among 50 patients with follow-up imaging, 23 patients (46%) showed facet joint fusion. The length of segmental stabilization was not a significant predictor of the occurrence of fusion. Pre- or postoperative radiation therapy, postoperative chemotherapy, and the location of spinal lesions did not have a statistically significant effect on the occurrence of fusion. Patients older than 60 years of age were more likely to have fusion across facet joints compared with younger patients. There was a significant difference in the mean visual analog scale pain score, with 6.28 preoperatively and 3.41 postoperatively, regardless of fusion status (p < 0.001). Cement extravasation was seen in 51% of the cohort, but in all instances, patients remained asymptomatic. Most importantly, the incidence of hardware failure was low (4%).

CONCLUSIONS

Percutaneous fixation with cement-augmented pedicle screws in patients with pathological spine fractures provides an improvement in mechanical back pain, with a low incidence of failure, and in some patients, spontaneous facet fusion was observed. Further research is necessary with regard to both short-term benefits and long-term outcomes.

Clinical Therapy of Metastatic Spinal Tumors

Metastatic spinal tumors (MST) have high rates of morbidity and mortality. MST can destroy the vertebral body or compress the nerve roots, resulting in an increased risk of pathological fractures and intractable pain. Here, we elaborately reviewed the currently available therapeutic options for MST according to the following four aspects: surgical management, minimally invasive therapy (MIT), radiation therapy, and systemic therapy. In particular, these aspects were classified and introduced to show their developmental process, clinical effects, advantages, and current limitations. Furthermore, with the improvement of treatment concepts and techniques, we discovered the prevalent trend toward the use of radiation therapy and MIT in clinic therapies. Finally, the future directions of these treatment options were discussed. We hoped that along with future advances and study will lead to the improvement of living standard and present status of treatment in patients with MST.

Minimally invasive spinal fixation in an aging population with osteoporosis: clinical and radiological outcomes and safety of expandable screws versus fenestrated screws augmented with polymethylmethacrylate

OBJECTIVE

The goal of this study was to compare the clinical and radiological outcomes between fenestrated pedicle screws augmented with cement and expandable pedicle screws in percutaneous vertebral fixation surgical procedures for the treatment of degenerative and traumatic spinal diseases in aging patients with osteoporosis.

METHODS

This was a prospective, single-center study. Twenty patients each in the expandable and cement-augmented screw groups were recruited. Clinical outcomes included visual analog scale (VAS), Oswestry Disability Index (ODI), and satisfaction rates. Radiographic outcomes comprised radiological measurements on the vertebral motion segment of the treated levels. Intraoperative data including complications were collected. All patients completed the clinical and radiological outcomes. Outcomes were compared preoperatively and postoperatively.

RESULTS

An average shorter operative time was found in procedures in which expandable screws were used versus those in which cement-augmented screws were used (p < 0.001). No differences resulted in perioperative blood loss between the 2 groups. VAS and ODI scores were significantly improved in both groups after surgery. There was no significant difference between the 2 groups with respect to baseline VAS or ODI scores. The satisfaction rate of both groups was more than 85%. Radiographic outcomes also showed no significant difference in segment stability between the 2 groups. No major complications after surgery were seen. There were 4 cases (20%) of approach-related complications, all in fenestrated screw procedures in which asymptomatic cement extravasations were observed. In 1 case the authors detected a radiologically evident osteolysis around a cement-augmented screw 36 months after surgery. In another case they identified a minor loosening of an expandable screw causing local back discomfort at the 3-year follow-up.

CONCLUSIONS

Expandable pedicle screws and polymethylmethacrylate augmentation of fenestrated screws are both safe and effective techniques to increase the pullout strength of screws placed in osteoporotic spine. In this series, clinical and radiological outcomes were equivalent between the 2 groups. To the authors’ knowledge, this is the first report comparing the cement augmentation technique versus expandable screws in the treatment of aging patients with osteoporosis.

Endoscopic surgical treatment for symptomatic spinal metastases in long-term cancer survivors

Background

To evaluate the feasibility of awake transforaminal endoscopic surgery in the management of symptomatic spinal metastases.

Methods

Transforaminal endoscopic spine procedures were performed by 1 surgeon in 325 patients over a period of 4 years from 2014 to 2018. Four of these patients suffered from radicular pain secondary to nerve compression from metastatic spine disease and are the basis of our analysis. Data was evaluated retrospectively in these patients with a minimum follow up of 1 year.

Results

All 4 patients treated with transforaminal endoscopic spine surgery for decompression of their metastatic spine disease had successful resolution of their symptoms without any perioperative complications and only brief recovery periods required.

Conclusions

Awake endoscopic surgery for the treatment of symptomatic metastatic spine disease is an effective outpatient surgical option for the treatment of patients suffering from radicular pain due to nerve compression from metastatic spine disease.

Minimally invasive spine surgeries for treatment of thoracolumbar fractures of spine: A systematic review

PURPOSE

Many minimally invasive surgical (MIS) techniques have been developed for instrumentation of spine. These MIS techniques restore stability, alignment while achieving return to function quite early as compared to open spine surgeries. The main aim of this review was to evaluate role, indications and complications of these MIS techniques in Thoracolumbar and Lumbar fractures.

METHODS

Pubmed search using key words such as"Percutaneous pedicle screw for Thoracolumbar fractures" and "Video Assisted Thoracoscopy, Thoracoscopic, VATS for thoracolumbar, Lumbar and Spine fractures" were used till July 2016 while doing literature search. Authors analyzed all the articles, which came after search; the articles relevant to the topic were selected and used for the study. Both prospective and retrospective case control studies and randomized control trials (RCT's) were included in this review. Case reports and reviews were excluded. Studies demonstrating use of MIS in cases other than spine trauma and studies with lack of clinical follow up were excluded from this review. Variables such as number of patients, operative time and complications were evaluated in each study.

RESULTS

After pubmed search, we found total 68 studies till July 2016 out of which eight studies were relevant for analysis of Video Assisted Thoracoscopy for thoracolumbar and lumbar fractures. Total 72 articles for Percutaneous pedicle screws in thoracolumbar and lumbar fractures were retrieved out of which percutaneous pedicle screws were analyzed in eleven studies and twelve studies involved comparison of percutaneous pedicle screws and conventional open techniques.

CONCLUSION

Role and Indications of the MIS techniques in spinal trauma are expanding quite rapidly. MIS techniques restore stability, alignment while achieving early return to function and lower infection rates as compared to open spine surgeries. In long term, they provide good kyphosis correction and stable fixation and fusion of spine. They are associated with long learning curve and technical challenges but with careful patient selection and in expert hands, MIS techniques may produce better results than open trauma spine surgeries.

Does the hip positioning matter for oblique lumbar interbody fusion approach? A morphometric study

PURPOSE

To evaluate whether left hip positioning widened the access corridor using oblique lateral interbody fusion (OLIF) approach during right lateral decubitus (RLD).

METHODS

Ten healthy adult volunteers underwent a T2 lumbosacral MRI (1.5 T) in the supine position, RLD position with left hip in extension and then in flexion. L2-L3 to L5-S1 disc spaces were identified. At each level, left psoas surface (in cm²), access corridor (in mm) and vessel movement were calculated in the three positions. Paired t test was used for comparison.

RESULTS

The mean surface of the left psoas ranged from 7.83 to 17.19 cm² in the three positions (p > 0.05). From L2-3 to L4-5, in RLD, when the left hip shifted from extension to flexion, nor the access corridor nor vessel movements were significantly different. When the volunteers shifted from supine to RLD position with hip in extension, arteries moved 3.66-5.61 mm to the right (p < 0.05 at L2-3, L3-4 and L5-S1), while the venous structures moved 0.92-4.96 mm (p < 0.05 at L2-3) to the right. When the position shifted from supine to RLD with hip in flexion, the arterial structures moved 0.47-4.88 mm (p < 0.05 at L2-3 and L3-4) to the right, while the venous structures moved - 0.94 to 4.13 mm (p < 0.05 at L2-3 and L3-4) to the right.

CONCLUSION

Hip positioning was not associated with a significant widening of the surgical corridor. To perform OLIF, we advocate for RLD position with left hip in extension to move away the vascular structures and reduce the psoas volume. These slides can be retrieved under Electronic Supplementary Material.

Minimally invasive lateral transpsoas approach for lumbar corpectomy and stabilization

Background

Here, we present our experience with the minimally invasive (MI) transpsoas approach for lumbar corpectomy and stabilization. Transpsoas approach accesses the lumbar spine and includes both the direct lateral interbody fusion and extreme lateral interbody fusion techniques. Both procedures utilize a tubular retractor system which facilitates adequate retraction and direct visualization of the target, while supposedly reducing soft tissue trauma.

Case Description

We evaluated two patients, one with a traumatic L2 wedge compression fracture and the other with an L3 pathological compression fracture due to multiple myeloma. Both patients underwent MI transpsoas lumbar corpectomy, anterior column reconstruction with an expandable cage, and posterior pedicle screw instrumentation to correct a kyphotic deformity. Both patients were mobilized on the 1^st postoperative day and experienced significant postoperative pain relief.

Conclusion

In two cases involving L2 and L3 compression fractures, MI transpsoas lumbar corpectomy was safely performed, with reduced perioperative and postoperative morbidity. Here, the transpsoas approach also allowed for early mobilization, adequate postoperative biomechanical stability, and resulted in immediate good outcomes.

Percutaneous Pedicle Screws in the Obese: Should the Skin Incision Be More Lateral?

Objective: To determine if the skin incision for lumbar percutaneous pedicle screws should be more lateral in the obese patient.

Methods: This was a retrospective radiographic analysis of 30 obese and non-obese lumbar spine computed tomography (CT) radiographs comparing the depth of soft tissue along the anatomic axis of the pedicle at L4 and L5.

Results: The average distance from the pedicle trajectory on the skin to the lateral border of the pedicle at L4 was 1.4 cm and 3.8 cm in the non-obese and obese groups, respectively. The average distance from the pedicle trajectory on the skin to the lateral border of the pedicle at L5 was 2.1 cm and 4.3 cm in the non-obese and obese groups, respectively; both these differences reached statistical significance, p <0.05.

Conclusions: This radiographic study supports a more lateral start point for percutaneous pedicle screws in obese patients to maintain an anatomic trajectory when inserting percutaneous pedicle screws into the lumbar spine at L4 and L5. If a skin incision is made at only 1 cm lateral to the pedicle in the obese patient, the surgeon often has to place significant traction on the skin edge to lateralize their instrumentation to achieve an appropriate angle of insertion. By making a more lateral skin incision, less manipulation of the skin and soft tissues is needed to maintain an anatomic trajectory of the pedicle screw. Decreasing soft tissue manipulation may decrease wound and instrumentation complications in this at-risk population.

Minimally Invasive Surgery for the Treatment of Traumatic Monosegmental Thoracolumbar Burst Fractures: Clinical and Radiologic Outcomes of 144 Patients With a 6-year Follow-Up Comparing Two Groups With or Without Intermediate Screw

STUDY DESIGN

This was a retrospective study of the clinical and radiologic outcomes of traumatic thoracolumbar (TL) burst fractures.

OBJECTIVES

We aimed to evaluate the clinical and radiologic outcomes after 6 years of follow-up of 144 patients with monosegmental TL burst fractures treated with percutaneous short-segment pedicle screw fixation, comparing two groups with versus without placement of an intermediate screw at the fractured vertebra.

SUMMARY OF BACKGROUND DATA

Traumatic TL fractures are the most common vertebral fractures, especially at the TL junction (T10-L2). Minimally invasive surgery (MIS) is a valuable treatment option for traumatic TL burst fractures.

MATERIALS AND METHODS

The clinical outcomes and radiologic parameters (Cobb angle, midsagittal index, and sagittal index) of 144 patients with traumatic monosegmental TL fractures treated with MIS were evaluated preoperatively, postoperatively, and after 3 and 6 years of follow-up. Patients were categorized into a nonintermediate screw group (nISG) and an intermediate screw group (ISG), and the groups were compared.

RESULTS

There were 71 patients (49.3%) in the nISG and 73 patients (50.7%) in the ISG. The radiologic parameters improved significantly more from the preoperative evaluation to the 6-year follow-up in the ISG than in the nISG (P<0.025). There were no significant differences in the mean Oswestry Disability Index (ODI) and Visual Analog Scale scores at the 6-year follow-up between the ISG and the nISG: 15.6% (ISG) versus 16.8% (nISG) for ODI (P<0.1) and 2.2 (ISG) versus 2.4 (nISG) for Visual Analog Scale score (P<0.85) (P<0.73).

CONCLUSIONS

MIS showed good clinical outcomes 6 years after surgery in both the ISG and the nISG. The additional intermediate screw significantly improved radiologic parameters but not clinical outcomes.

Risedronate-Loaded Macroporous Gel Foam Enriched with Nanohydroxyapatite: Preparation, Characterization, and Osteogenic Activity Evaluation Using Saos-2 Cells

The application of minimally invasive surgical techniques in the field of orthopedic surgery has created a growing need for new injectable synthetic materials that can be used for bone grafting. In this work, novel injectable thermosensitive foam was developed by mixing nHAP powder with a thermosensitive polymer with foaming power (Pluronic F-127) and loaded with a water-soluble bisphosphonate drug (risedronate) to promote osteogenesis. The foam was able to retain the porous structure after injection and set through temperature change of PF-127 solution to form gel inside the body. The effect of different formulation parameters on the gelation time, porosity, foamability, injectability, and in vitro degradation in addition to drug release from the prepared foams were analyzed using a full factorial design. The addition of a co-polymer like methylcellulose or sodium alginate into the foam was also studied. Results showed that the prepared optimized thermosensitive foam was able to gel within 1 min at 37°C, and sustain the release of drug for 72 h. The optimized formulation was further tested for any interactions using DSC and IR, and revealed no interactions between the drug and the used excipients in the prepared foam. Furthermore, the ability of the pre-set foam to support osteoblastic-like Saos-2-cell proliferation and differentiation was assessed, and revealed superior function on promoting cellular proliferation as confirmed by fluorescence microscope compared to the plain drug solution. The activity of the foam treated cells was also assessed by measuring the alkaline phosphatase activity and calcium deposition, and confirmed that the cellular activity was greatly enhanced in foam treated cells compared to those treated with the plain drug solution only. The obtained results show that the prepared risedronate-loaded thermosensitive foam would represent a step forward in the design of new materials for minimally invasive bone regeneration.

Percutaneous fixation of thoracolumbar vertebral fractures

Surgical treatment of patients with thoracolumbar vertebral fracture without neurological deficit is still controversial.

Management of vertebral fracture with percutaneous fixation was first reported in 2004.

Advantages of percutaneous fixation are: less tissue dissection; decreased post-operative pain; decreased bleeding and operative time (depending on the steep learning curve); better screw positioning with fluoroscopy compared with an open freehand technique; and a decreased infection rate.

The limitations of percutaneous fixation of vertebral fractures include increased radiation exposure to the patient and the surgeon, together with the steep learning curve for this technique.

Adding a screw at the level of the fractured vertebra has the advantages of incorporating fewer motion segments with less operative time and bleeding. This also increases the axial, sagittal and torsional stiffness of the construct.

Percutaneous fixation alone without grafting is sufficient for treating type A and B1 (AO classification) thoracolumbar fractures with satisfactory results concerning kyphosis reduction when compared with open instrumentation and fusion and with open fixation.

Type C and B2 fractures (ligamentous injuries) should undergo fusion since the ligamentous healing is mechanically weak, increasing the risk of instability.

This review offers a detailed description of percutaneous screw insertion and discusses the advantages and disadvantages.

Cite this article: EFORT Open Rev 2018;3:604-613. DOI: 10.1302/2058-5241.3.170026.

Indications for the monosegmental stabilization of thoraco-lumbar spine fractures

PURPOSE

To evaluate the efficacy and to underline the right indications of the posterior monosegmental stabilization for the treatment of thoraco-lumbar spine fractures.

METHOD

Twenty patients underwent a monosegmental stabilization at our Institution and were retrospectively reviewed with a minimum follow-up of two years. All the patients had a clinical and radiological assessment before, after the surgery and at final follow-up. All data were evaluated by one independent observer. Data collected were Denis pain and work scale, somatic kyphosis (SK), somatic height (SH), and compression percentage (CP).

RESULTS

The mean pre-operative SK angle measured between the upper and lower end plate of the fractured vertebra was 23.6°. The mean SK immediately after surgery was 12.8° and at final follow-up was 13.9°. The mean pre-operative SH was 21.9 mm, the mean value after surgery was 26.5 mm, and at final follow-up was 24.8 mm. The mean pre-operative CP was 66.7%, the mean value after surgery was 80.9%, and at final follow-up was 75.3%. At final follow-up, 75% of the patients had no pain or moderate pain and 95% of the patients returned to a full time work.

CONCLUSIONS

Monosegmental stabilization with fusion is a safe and effective method to treat well selected thoracolumbar spine fractures. The right indications are type A1, type B2, and type A3 with a load sharing of less than 7 points and some very well selected type C fractures in which there is not lateral and rotatory displacement.

Percutaneous versus open pedicle screw instrumentation in treatment of thoracic and lumbar spine fractures: A systematic review and meta-analysis

BACKGROUND

To assess the safety and efficacy of percutaneous short-segment pedicle instrumentation compared with conventionally open short-segment pedicle instrumentation and provide recommendations for using these procedures to treat thoracolumbar fractures.

METHODS

The Medline database, Cochrane database of Systematic Reviews, Cochrane Clinical Trial Register, and Embase were searched for articles published. The randomized controlled trials (RCTs) and non-RCTs that compared percutaneous short-segment pedicle instrumentation to open short-segment pedicle instrumentation and provided data on safety and clinical effects were included. Demographic characteristics, clinical outcomes, radiological outcomes, and adverse events were manually extracted from all of the selected studies. Methodological quality of included studies using Methodological Index for Non-Randomized Studies scale and Cochrane collaboration's tool for assessing the risk of bias by 2 reviewers independently.

RESULTS

Nine studies encompassing 433 patients met the inclusion criteria. Subgroup meta-analyses were performed according to the study design. The pooled results showed there were significant differences between the 2 techniques in short- and long-term visual analog scale, intraoperative blood loss, operative time, postoperative draining loss, hospital stay, and incision size, although there were no significant differences in postoperative radiological outcomes, Oswestry Disability Index, hospitalization cost, intraoperative fluoroscopy time, and adverse events.

CONCLUSION

Percutaneous short-segment pedicle instrumentation in cases with achieve satisfactory results, could replace in many cases extensive open surgery and not increased related complications. However, further high-quality RCTs are needed to assess the long-term outcome of patients between 2 techniques.

A novel, percutaneous, self-expanding, forceful reduction screw system for the treatment of thoracolumbar fracture with severe vertebral height loss

Background

Over the past decade, the techniques for minimally invasive spinal stabilization have improved significantly. The multiaxial screw utilized in minimally invasive operations is limited in restoring fracture height, reconstructing the anterior vertebral column, and improving kyphosis. Therefore, the percutaneous, minimally invasive approach is not recommended for a thoracolumbar fracture with severe vertebral height loss. We report our novel, percutaneous, self-expanding, forceful reduction screw system to address this problem.

Methods

Thirty-eight patients experiencing thoracolumbar fracture, with a vertebral height loss more than 50%, were treated with the novel, percutaneous, self-expanding, forceful reduction screw between March 2014 and June 2015. The patients’ charts and radiographs were reviewed. The vertebral body index (VBI), height of the anterior margin of fractured vertebra (HAMFV), vertebral body angle (VBA), bisegmental Cobb angle (BCA), and Oswestry disability index (ODI) scores were obtained before and after the operation, as well as during the 2-year follow-up. The scoring results were compared using t tests.

Results

The operation was completed successfully in 38 patients. A total of 152 screws were placed. The average operation time was 90.7 ± 21.9 min, and the average intraoperative bleeding amount was 89.2 ± 31.9 ml. The patients were discharged at a mean of 3.2 ± 0.9 postoperative days, with a mean hospital stay of 4.8 ± 1.0 days. The VBI, HAMFV, VBA, and BCA scores were significantly improved after treatment with the novel screw system; there was a significant difference between pre- and postoperative parameters (p < 0.05). Although the decreases in all of the parameters were variable during the 2-year follow-up, there were no statistical differences between the postoperative imaging parameters and the last follow-up imaging parameters (p > 0.05). The ODI score at the last follow-up examination was 5.9 ± 2.7, which was significantly improved compared with the preoperative score of 44.6 ± 2.3 (p < 0.05).

Conclusions

We believe that the novel, percutaneous, self-expanding, forceful reduction screw system developed by us not only successfully expands the minimally invasive percutaneous surgery to the thoracolumbar fracture with severe vertebral height loss but also achieves significant vertebral height restoration and kyphosis correction.

Accuracy of percutaneous pedicle screws for thoracic and lumbar spine fractures compared with open technique

BACKGROUND

This study aimed to compare the accuracy of screw placement between open pedicle screw fixation and percutaneous pedicle screw fixation (MIS) for the treatment of thoracolumbar spine fractures (TSF).

METHODS

forty-nine patients with acute TSF who were treated with transpedicular screw fixation from January 2013 to December 2016 were retrospectively reviewed. The patients were divided into Open and MIS groups. Laminectomy was performed in either group if needed. The accuracy of the screw placement, the evolution of the Cobb sagittal angle postoperatively and at 12-month follow-up and the neurological status were recorded. AO type of fracture and TLICS score were also recorded.

RESULTS

Mean age was 42 years old. Mean TLICS score was 6.29 and 5.96 for open and MIS groups respectively. Twenty-five MIS and 24 open surgeries were performed, and 350 (175 in each group) screws were inserted (7.14 per patient). Twenty-four and 13 screws were considered "out" in the open and MIS groups respectively (Odds ratio 1.98. 0.97-4,03 P=0.056). The Cobb sagittal angle went from 13.3º to 4.5º and from 14.9º to 8.2º in the Open and MIS groups respectively (both P<0.0001). Loss of correction at 12-month follow-up was 3.2º and 4.2º for the open and MIS groups, respectively. No neurological worsening was observed.

CONCLUSIONS

For the treatment of acute thoracolumbar fractures, the MIS technique seems to achieve similar results to the open technique in relation to neurological improvement and deformity correction, while placing the screws more accurately.

Outcomes of oblique lateral interbody fusion for degenerative lumbar disease in patients under or over 65 years of age

Background

Oblique lateral interbody fusion (OLIF) offers the solution to problems of anterior lumbar interbody fusion (ALIF) and lateral lumbar interbody fusion (LLIF). However, OLIF technique for degenerative spinal diseases of elderly patients has been rarely reported. The objective of this study was to determine the clinical and radiological results of OLIF technique for degenerative spinal diseases in patients under or over 65 years of age.

Methods

Sixty-three patients who underwent OLIF procedure were enrolled, including 29 patients who were less than 65 years of age and 34 patients who were over 65 years of age. Fusion rate, change of disc height and lumbar lordotic angle, Numeric Rating Scale (NRS), return to daily activity, patient’s satisfaction rate (PSR), and Oswestry disability index (ODI) were used to assess clinical and functional outcomes.

Results

The mean NRS scores for back and leg pain decreased, respectively, from 4.6 and 5.9 to 2.3 and 1.8 in the group A (less than 65 years) and from 4.5 and 6.8 to 2.6 and 2.2 in the group B (over 65 years) at the final follow-up period. The mean ODI scores improved from 48.4 to 24.0% in the group A and from 46.5 to 25.2% in the group B at the final follow-up period. In both groups, the NRS and ODI scores significantly changed preoperatively to postoperatively (p <  0.001). However, statistical analysis yielded no significant difference in postoperative NRS/ODI scores between two groups. In both groups, the changes in the disc height, segmental lordosis, and fusion rate between the preoperative and postoperative periods were significant. The amount of change between preoperative and postoperative disc height, segmental lordosis, and whole lumbar lordosis demonstrated significant intergroup differences (p <  0.05). Overall perioperative complications occurred in 8 of 29 (27.6%) patients in the group A and in 10 of 34 (29.4%) patients in the group B. In both groups, the major complication incidence was 0 and 3%, respectively.

Conclusion

Although there was the slightly high incidence of complication associated with high rate of co-morbidities in elderly patients, OLIF for degenerative lumbar diseases in elderly patients showed favorable clinical and radiological outcomes.

Technical pearls and surgical outcome of early transitional period experience in minimally invasive lumbar discectomy: A prospective study

Background:

There is growing indications of minimally invasive spine surgery. The inherent attitude and institutive learning curve limit transition from standard open surgery to minimally invasive surgery demanding understanding of new instruments and correlative anatomy.

Materials and Methods:

In this prospective study, 80 patients operated for lumbar disc prolapse were included in the study (between January 2016 and March 2018). Fifty patients (Group A) operated by various minimally invasive spine surgery (MISS) techniques for herniated disc disease were compared with randomly selected 30 patients (Group B) operated between the same time interval by standard open approach. Surgical outcome with Oswestry Disability Index (ODI) and patient satisfaction score was calculated in pre- and postoperative periods.

Results:

Mean preoperative ODI score in Group A was 31.52 ± 7.5 standard deviation (SD) (range: 6“46; interquartile range [IQR]: 8; median: 32.11) and postoperative ODI score was 9.20 ± 87.8 SD (range: 0“38; IQR: 11; median: 6.67). Mean preoperative ODI score in Group B was 26.47 ± 4.9 SD (range: 18“38; IQR: 4; median: 25) and postoperative ODI score was 12.27 ± 8.4 SD (range: 3“34; IQR: 12; median: 10.0). None of the patients was unsatisfied in either group. On comparing the patient satisfaction score among two groups, no significant difference (P = 0.27) was found.

Discussion:

On comparing the change in ODI and preoperative ODI among both groups, we found a significant difference between the groups. It is worth shifting from open to MISS accepting small learning curve. The satisfaction score of MISS in early transition period is similar to open procedure.

Conclusion:

The MISS is safe and effective procedure even in transition period for the central and paracentral prolapsed lumbar intervertebral disc treatment. The results are comparable, and patient satisfaction and symptomatic relief are not compromised.

[Percutaneous pedicle screw fixation and minimally invasive decompression in the same incision for type A3 thoracolumbar burst fracture]

Objective

To assess the effectiveness of percutaneous pedicle screw fixation and minimally invasive decompression in the same incision for type A3 thoracolumbar burst fracture.

Methods

Between May 2014 and February 2016, 43 cases of type A3 thoracolumbar burst fracture with or without nerve symptoms were treated with pedicle screw fixation and neural decompression. Of them, 21 patients underwent percutaneous pedicle screw fixation and minimally invasive decompression in the same incision (percutaneous group), and the other 22 patients underwent traditional open surgery (open group). There was no significant difference in gender, age, cause of injury, fractures level, preoperative American Spinal Injury Association (ASIA) grade, thoracolumbar injury classification and severity (TLICS) score, load-sharing classification, height of injury vertebrae, kyphotic Cobb angle, and spinal canal encroachment between 2 groups ( P>0.05). The length of soft tissue dissection, operation time, intraoperative blood loss, postoperative drainage, X-ray exposure times, and incision visual analogue scale (VAS) score at 1 day after operation were recorded and compared. At last follow-up, Japanese Orthopaedic Association (JOA) score and low back pain VAS score were recorded and compared respectively. The ASIA grade recovery was evaluated; the height of injury vertebrae, kyphotic Cobb angle, and spinal canal encroachment were assessed postoperatively.

Results

Percutaneous group was significantly better than open group in the length of soft tissue dissection, intraoperative blood loss, postoperative drainage, and incision VAS at 1 day after operation ( P<0.05), but no significant difference was found in operation time between 2 groups ( P>0.05); however, X-ray exposure times of open group were significantly better than that of percutaneous group ( P<0.01). The patients were followed up 12 to 19 months (mean, 15.1 months) in 2 groups. All patients achieved effective decompression. No complications of iatrogenic neurological injury and internal fixation failure occurred. The height of injury vertebrae, kyphotic Cobb angle, and spinal canal encroachment of the fractured vertebral body were significantly improved at 3 days after operation when compared with preoperative ones ( P<0.05), but no significant difference was found between 2 groups ( P>0.05). At last follow-up, JOA score and low back pain VAS score of percutaneous group were significantly better than those of open group ( P<0.05). The neurological function under grade E was improved at least one ASIA grade in 2 groups, but no significant difference was shown between 2 groups ( Z=0.480, P=0.961).

Conclusion

Percutaneous pedicle screw fixation and minimally invasive decompression in the same incision for type A3 thoracolumbar burst fracture has satisfactory effectiveness. And it has the advantages of minimal trauma, quick recovery, safeness, and reliableness.

Answer to the Letter to the Editor of Y. Zhao et al. concerning "Percutaneous versus traditional and paraspinal posterior open approaches for treatment of thoracolumbar fractures without neurologic deficit: a meta-analysis'' by Sun XY, Zhang XN, Hai Y: Eur Spine J (2016); doi:10.1007/s00586-016-4818-4

PURPOSE

This study evaluated differences in outcome variables between percutaneous, traditional, and paraspinal posterior open approaches for traumatic thoracolumbar fractures without neurologic deficit.

METHODS

A systematic review of PubMed, Cochrane, and Embase was performed. In this meta-analysis, we conducted online searches of PubMed, Cochrane, Embase using the search terms "thoracolumbar fractures", "lumbar fractures", ''percutaneous'', "minimally invasive", ''open", "traditional", "posterior", "conventional", "pedicle screw", "sextant", and "clinical trial". The analysis was performed on individual patient data from all the studies that met the selection criteria. Clinical outcomes were expressed as risk difference for dichotomous outcomes and mean difference for continuous outcomes with 95 % confidence interval. Heterogeneity was assessed using the χ ² test and I ² statistics.

RESULTS

There were 4 randomized controlled trials and 14 observational articles included in this analysis. Percutaneous approach was associated with better ODI score, less Cobb angle correction, less Cobb angle correction loss, less postoperative VBA correction, and lower infection rate compared with open approach. Percutaneous approach was also associated with shorter operative duration, longer intraoperative fluoroscopy, less postoperative VAS, and postoperative VBH% in comparison with traditional open approach. No significant difference was found in Cobb angle correction, postoperative VBA, VBA correction loss, Postoperative VBH%, VBH correction loss, and pedicle screw misplacement between percutaneous approach and open approach. There was no significant difference in operative duration, intraoperative fluoroscopy, postoperative VAS, and postoperative VBH% between percutaneous approach and paraspianl approach.

CONCLUSIONS

The functional and the radiological outcome of percutaneous approach would be better than open approach in the long term. Although trans-muscular spatium approach belonged to open fixation methods, it was strictly defined as less invasive approach, which provided less injury to the paraspinal muscles and better reposition effect.

Oblique Lumbar Interbody Fusion for Revision of Non-union Following Prior Posterior Surgery: A Case Report

We report the case of a 75-year-old lady who presented with a L2-3 non-union 18 months following a L2-3 and L3-4 posterior decompression and transforaminal lumbar interbody fusion. Halo of the L2 pedicle screws on imaging was consistent with a non-union at the L2-3 level. An anterior lumbar interbody fusion (ALIF) approach was originally considered. However, due to the high lumbar approach and patient habitus [body mass index (BMI) > 35], a decision was made to approach the L2-3 level using an oblique technique. This involved dissection anterior to the psoas muscle to access the L2-3 disc space. The psoas, kidney and retroperitoneum were retracted using a Synframe for the oblique trajectory. Removal of the prior trans-foraminal lumbar interbody fusion cage was performed via the oblique approach and insertion of a revised implant. The operation was completed successfully with no perioperative complications noted. Length of stay was 3 days, with the patient achieving rapid pain relief. In the present report, we report the first case using an oblique lumbar interbody fusion (OLIF) approach for revision of a prior posterior fusion non-union at the L2,3 level. The OLIF technique is feasible for revision of a non-union of upper lumbar levels, with satisfactory fusion achieved with acceptable feasibility.

Effect of the percutaneous pedicle screw fixation at the fractured vertebra on the treatment of thoracolumbar fractures

PURPOSE

The purpose of this study was to evaluate the efficacy and safety of percutaneous pedicle screw fixation at the fractured vertebra in the treatment of thoracolumbar fractures.

METHODS

Thirty-two consecutive patients were enrolled in the study. All patients received percutaneous pedicle screw fixation, and they were randomly divided into two groups to undergo either the placement of pedicle screws into the fractured vertebra (fractured group) or not (control group). The operation time and intra-operative blood loss were recorded. Oswestry disability index (ODI) questionnaire and visual analogue scale (VAS) as clinical assessments were quantified. Radiographic follow-up was defined by the vertebral body index (VBI), anterior vertebral body height (AVBH), and Cobb angle (CA).

RESULTS

No significant difference was observed in the operation time and intra-operative blood loss between the two groups. Clinical results (VAS and ODI scores) showed no significant difference during all the follow-up periods. In the fractured group, there were better correction and less loss of AVBH and VBI compared with the control group. However, post-operative correction of the CA immediately after surgery and the correction loss at the final follow-up showed no significant difference between the two groups.

CONCLUSION

Percutaneous screw fixation combined with intermediate screws at the fractured vertebra could more effectively restore and maintain fractured vertebral height, and is an acceptable, minimally invasive surgical choice for patients with type A thoracolumbar fractures.

Cost-utility of minimally invasive versus open transforaminal lumbar interbody fusion: systematic review and economic evaluation

PURPOSE

To assess the cost-utility and perioperative costs of minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) versus open-TLIF for degenerative lumbar pathologies.

METHODS

Relevant articles were identified from six electronic databases. Predefined end points were extracted and meta-analysis conducted from the identified studies.

RESULTS

For each study, the direct hospital cost for MI-TLIF was found to be less than that of open-TLIF. When these outcomes were pooled, direct hospital costs were found to be significantly lower in the MI-TLIF group [weighted mean difference (WMD), -$2820; I (2) = 61 %; P < 0.00001]. MI-TLIF was also associated with shorter hospitalization (WMD, 0.99; 95 % CI -1.81, -0.17; I (2) = 96 %; P = 0.02), trend toward reduced complications (relative risk 0.53; 95 % CI 0.23, 1.06; I (2) = 0 %; P = 0.07), and reduced blood loss (WMD, -246.40 mL; I (2) = 98 %; P = 0.003), but was not associated with a significant difference in operation time (WMD, -67.05; 95 % CI -169.44, 35.35; I (2) = 100 %; P = 0.20).

CONCLUSIONS

From the limited evidence, the available data suggest a trend of significantly reduced perioperative costs, length of stay, and blood loss for minimally invasive compared with open surgical approaches for TLIF. MI-TLIF may represent an opportunity for optimal utilization and allocation of health-care resources from both a hospital and societal perspective.

Short-segment percutaneous pedicle screw fixation with cement augmentation for tumor-induced spinal instability

BACKGROUND CONTEXT

Pathologic vertebral compression fractures (VCFs) represent a major source of morbidity and diminished quality of life in the spinal oncology population. Procedures with low morbidity that effectively treat patients with pathologic fractures are especially important in the cancer population where life expectancy is limited. Vertebroplasty and kyphoplasty are often not effective for mechanically unstable pathologic fractures extending into the pedicle and facet joints. Combination of cement augmentation and percutaneous instrumented stabilization represents a minimally invasive treatment option that does not delay radiation and systemic therapy.

PURPOSE

The objective of the study was to evaluate the safety and efficacy of cement-augmented short-segment percutaneous posterolateral instrumentation for tumor-associated VCF with pedicle and joint involvement.

METHODS

Forty-four consecutive patients underwent cement-augmented percutaneous spinal fixation for unstable tumors between 2011 and 2014. Retrospective analysis of prospectively collected data, including visual analog pain scale (VAS) response score and procedural complications, was performed.

RESULTS

Patients with a median composite Spinal Instability Neoplastic Scale score of 10 (range=8-15) were treated with constructs spanning one to four disk spaces (median of two spaces, constituting 84% of all cases). The proportion of patients with severe pain decreased from 86% preoperatively to 0%; 65% of patients reported no referable instability pain postoperatively. There was one adjacent-level fracture responsive to kyphoplasty, and one case of asymptomatic screw pullout. Two patients subsequently required decompression in the setting of disease progression despite radiation; there was no perioperative morbidity.

CONCLUSIONS

Percutaneous cement-augmented posterolateral spinal fixation is a safe and effective option for palliation of appropriately selected mechanically unstable VCF that extends into pedicle and/or joint.

Percutaneous versus open pedicle screw fixation for treatment of thoracolumbar fractures: Systematic review and meta-analysis of comparative studies

BACKGROUND

The main aims of managing thoracolumbar fractures involve stabilization of traumatized regions, to promote vertebral healing or segmental fusion. Recently, percutaneous pedicle screw fixation has evolved as an alternative approach for the treatment of thoracolumbar fractures, aiming to minimize soft tissue injury and perioperative morbidity. A systematic review and meta-analysis was conducted to compare outcomes of percutaneous versus open pedicle screw fixation for thoracolumbar fractures.

METHODS

Relevant articles were identified from six electronic databases from their inception to December 2014.

RESULTS

From 12 relevant studies identified, 279 patients undergoing percutaneous fixation were compared with 340 open fixation procedures. Operative duration was significantly shorter in the percutaneous group by 19 min (P = 0.0002). The percutaneous approach was also associated with shorter hospital stay by 5.7 days (P = 0.0007). Whilst there was no difference in screw malpositioning (RR, 0.77; 95% CI, 0.33, 1.83; P = 0.56), the percutaneous approach had lower rates of infections (RR, 0.36; 95% CI, 0.13, 1.00; P = 0.05), and superior visual analogue scale clinical outcomes (P = 0.001). No difference was found between the groups in terms of postoperative Cobb angle (P = 0.22), postoperative body angle (P = 0.66), and postoperative anterior body height (P = 0.19).

CONCLUSIONS

The percutaneous approach was associated with shorter operative duration and hospital stay, reduced intraoperative blood loss and reduced infection rates. Given the lack of robust clinical evidence, these findings warrant verification in large prospective registries and randomized trials.

Comparison of minimally invasive surgery with standard open surgery for vertebral thoracic metastases causing acute myelopathy in patients with short- or mid-term life expectancy: surgical technique and early clinical results

OBJECT Spinal metastasis is common in patients with cancer. About 70% of symptomatic lesions are found in the thoracic region of the spine, and cord compression presents as the initial symptom in 5%-10% of patients. Minimally invasive spine surgery (MISS) has recently been advocated as a useful approach for spinal metastases, with the aim of decreasing the morbidity associated with more traditional open spine surgery; furthermore, the recovery time is reduced after MISS, such that postoperative chemotherapy and radiotherapy can begin sooner. METHODS Two series of oncological patients, who presented with acute myelopathy due to vertebral thoracic metastases, were compared in this study. Patients with complete paraplegia for more than 24 hours and with a modified Bauer score greater than 2 were excluded from the study. The first group (n = 23) comprised patients who were prospectively enrolled from May 2010 to September 2013, and who were treated with minimally invasive laminotomy/laminectomy and percutaneous stabilization. The second group (n = 19) comprised patients from whom data were retrospectively collected before May 2010, and who had been treated with laminectomy and stabilization with traditional open surgery. Patient groups were similar regarding general characteristics and neurological impairment. Results were analyzed in terms of neurological recovery (American Spinal Injury Association grade), complications, pain relief (visual analog scale), and quality of life (European Organisation for Research and Treatment of Cancer [EORTC] QLQ-C30 and EORTC QLQ-BM22 scales) at the 30-day follow-up. Operation time, postoperative duration of bed rest, duration of hospitalization, intraoperative blood loss, and the need and length of postoperative opioid administration were also evaluated. RESULTS There were no significant differences between the 2 groups in terms of neurological recovery and complications. Nevertheless, the MISS group showed a clear and significant improvement in terms of blood loss, operation time, and bed rest length, which is associated with a more rapid functional recovery and discharge from the hospital. Postoperative pain and the need for opioid administration were also significantly less pronounced in the MISS group. Results from the EORTC QLQ-C30 and QLQ-BM22 scales showed a more pronounced improvement in quality of life at follow-up in the MISS group. CONCLUSIONS In the authors' opinion, MISS techniques should be considered the first choice for the treatment for patients with spinal metastasis and myelopathy. MISS is as safe and effective for spinal cord decompression and spine fixation as traditional surgery, and it also reduces the impact of surgery in critical patients. However, further studies are needed to confirm these findings.

Minimally invasive versus open transforaminal lumbar interbody fusion for treatment of degenerative lumbar disease: systematic review and meta-analysis

PURPOSE

While open TLIF (O-TLIF) remains the mainstay approach, minimally invasive TLIF (MI-TLIF) may offer potential advantages of reduced trauma to paraspinal muscles, minimized perioperative blood loss, quicker recovery and reduced risk of infection at surgical sites. This meta-analysis was conducted to provide an updated assessment of the relative benefits and risks of MI-TLIF versus O-TLIF.

METHODS

Electronic searches were performed using six databases from their inception to December 2014. Relevant studies comparing MI-TLIF and O-TLIF were included. Data were extracted and analysed according to predefined clinical end points.

RESULTS

There was no significant difference in operation time noted between MI-TLIF and O-TLIF cohorts. The median intraoperative blood loss for MI-TLIF was significantly lower than O-TLIF (median: 177 vs 461 mL; (weighted mean difference) WMD, -256.23; 95% CI -351.35, -161.1; P < 0.00001). Infection rates were significantly lower in the minimally invasive cohort (1.2 vs 4.6%; relative risk (RR), 0.27; 95%, 0.14, 0.53; I2) = 0%; P = 0.0001). VAS back pain scores were significantly lower in the MI-TLIF group compared to O-TLIF (WMD, -0.41; 95% CI -0.76, -0.06; I2 = 96%; P < 0.00001). Postoperative ODI scores were also significantly lower in the minimally invasive cohort (WMD, -2.21; 95% CI -4.26, -0.15; I2 = 93%; P = 0.04).

CONCLUSIONS

In summary, the present systematic review and meta-analysis demonstrated that MI-TLIF appears to be a safe and efficacious approach compared to O-TLIF. MI-TLIF is associated with lower blood loss and infection rates in patients, albeit at the risk of higher radiation exposure for the surgical team. The long-term relative merits require further validation in prospective, randomized studies.

Pure percutaneous pedicle screw fixation without arthrodesis of 32 thoraco-lumbar fractures: clinical and radiological outcome with 36-month follow-up

PURPOSE

To evaluate the outcome of pure percutaneous fixation of unstable single level fractures at the thoraco-lumbar junction (A1 to B2 Magerl/AO Spine).

METHOD

Neurological intact patients were included in a 2-year prospective study (follow-up 36 months). Two groups were considered: the group in which additional short bilateral screws in the fractured vertebra were placed was called lordorizing screw group (LSG), the other was called non lordorizing screw group (nLSG). Clinical outcome was evaluated using the SF-36, the Oswestry disability index and the recovery time needed to go back work. The following radiological parameters were also evaluated on the follow-up exams: the Mid-Sagittal Index, the Cobb's angle and the Sagittal Index.

RESULTS

In the LSG, the correction values of MSI, Cobb's angle and SI were statistically significantly higher than in nLSG.

CONCLUSION

When feasible we recommend a pure percutaneous short segment pedicle screw fixation adding a lordorizing screw.

Minimally invasive procedures on the lumbar spine

Degenerative disease of the lumbar spine is a common and increasingly prevalent condition that is often implicated as the primary reason for chronic low back pain and the leading cause of disability in the western world. Surgical management of lumbar degenerative disease has historically been approached by way of open surgical procedures aimed at decompressing and/or stabilizing the lumbar spine. Advances in technology and surgical instrumentation have led to minimally invasive surgical techniques being developed and increasingly used in the treatment of lumbar degenerative disease. Compared to the traditional open spine surgery, minimally invasive techniques require smaller incisions and decrease approach-related morbidity by avoiding muscle crush injury by self-retaining retractors, preventing the disruption of tendon attachment sites of important muscles at the spinous processes, using known anatomic neurovascular and muscle planes, and minimizing collateral soft-tissue injury by limiting the width of the surgical corridor. The theoretical benefits of minimally invasive surgery over traditional open surgery include reduced blood loss, decreased postoperative pain and narcotics use, shorter hospital length of stay, faster recover and quicker return to work and normal activity. This paper describes the different minimally invasive techniques that are currently available for the treatment of degenerative disease of the lumbar spine.

Complications with K-wire insertion for percutaneous pedicle screws

STUDY DESIGN

Retrospective study.

OBJECTIVE

To determine the risk profile and complications associated with anterior vertebral body breach by Kirschner (K)-wire during percutaneous pedicle screw insertion.

SUMMARY OF BACKGROUND DATA

Percutaneous techniques and indications are rapidly expanding with numerous studies now supporting the use of percutaneous pedicle screw stabilization as an adjunct for multiple pathologies such as degenerative, tumor, and trauma. With regards to complication rates, little has been documented.

MATERIALS AND METHODS

A total of 525 consecutive percutaneous pedicle screws were retrospectively reviewed and the rate of anterior vertebral body breach was recorded, including any potential adverse clinical outcomes.

RESULTS

Of 525 percutaneous pedicle screw insertions, there were 7 anterior breaches recorded. We rated the breaches as a minor breach (<5 mm; n=3), moderate breach (5-25 mm; n=2), and major breach (>25 mm; n=2). Two patients had a postoperative ileus with a retroperitoneal hematoma on postoperative computed tomography scan. No patient required reoperation or blood transfusion.

CONCLUSIONS

The indications for minimally invasive spinal fusion have expanded to include conditions such as degenerative, trauma, deformity, infection, and neoplasia. Although the rate of anterior K-wire breach is low, the technique requires the acquisition of a new set of skills including the safe passage of a K-wire, and knowledge of potential complications that may ensue.

Minimally invasive versus open surgery for cervical and lumbar discectomy: a systematic review and meta-analysis

INTRODUCTION

Minimally invasive surgery for discectomy may accelerate recovery and reduce pain, but it also requires technical expertise and is associated with increased risks. We performed a meta-analysis to determine the effects of minimally invasive versus open surgery on functional outcomes, pain, complications and reoperations among patients undergoing cervical or lumbar discectomy.

METHODS

We searched MEDLINE, Embase and the Cochrane Library for reports of relevant randomized controlled trials published to Jan. 12, 2014. Two reviewers assessed the eligibility of potential reports and the risk of bias of included trials. We analyzed functional outcomes and pain using standardized mean differences (SMDs) that were weighted and pooled using a random-effects model.

RESULTS

We included 4 trials in the cervical discectomy group (n = 431) and 10 in the lumbar discectomy group (n = 1159). Evidence overall was of low to moderate quality. We found that minimally invasive surgery did not improve long-term function (cervical: SMD 0.11, 95% confidence interval [CI] -0.09 to 0.31; lumbar: SMD 0.04, 95% CI -0.11 to 0.20) or reduce long-term extremity pain (cervical: SMD -0.21, 95% CI -0.52 to 0.10; lumbar: SMD 0.08, 95% CI -0.16 to 0.32) compared with open surgery. The evidence suggested overall higher rates of nerve-root injury (risk ratio [RR] 1.62, 95% CI 0.45 to 5.84), incidental durotomy (RR 1.56, 95% CI 0.80 to 3.05) and reoperation (RR 1.48, 95% CI 0.97 to 2.26) with minimally invasive surgery than with open surgery. Infections were more common with open surgery than with minimally invasive surgery (RR 0.24, 95% CI 0.04 to 1.38), although the difference was not statistically significant.

INTERPRETATION

Current evidence does not support the routine use of minimally invasive surgery for cervical or lumbar discectomy. Well-designed trials are needed given the lack of high-quality evidence.

Treatment of thoracolumbar trauma by short-segment percutaneous transpedicular screw instrumentation: prospective comparative study with a minimum 2-year follow-up

Object

The main aim of this study was to compare clinical and radiological outcomes after stabilization by a percutaneous transpedicular system and stabilization from the standard open approach for thoracolumbar spine injury.

Methods

Thirty-seven consecutive patients were enrolled in the study over a period of 16 months. Patients were included in the study if they experienced 1 thoracolumbar fracture (A3.1–A3.3, according to the AO/Magerl classification), had an absence of neurological deficits, had no other significant injuries, and were willing to participate. Eighteen patients were treated by short-segment, minimally invasive, percutaneous pedicle screw instrumentation. The control group was composed of 19 patients who were stabilized using a short-segment transpedicular construct, which was performed through a standard midline incision. The pain profile was assessed by a visual analog scale (VAS), and overall satisfaction by a simple 4-stage scale relating to performance of daily activities. Working ability and return to original occupation were also monitored. Radiographic follow-up was defined by the vertebral body index (VBI), vertebral body angle (VBA), and bisegmental Cobb angle. The accuracy of screw placement was examined using CT.

Results

The mean surgical duration in the percutaneous screw group was 53 ± 10 minutes, compared with 60 ± 9 minutes in the control group (p = 0.032). The percutaneous screw group had a significantly lower perioperative blood loss of 56 ± 17 ml, compared with 331 ± 149 ml in the control group (p < 0.001). Scores on the VAS in patients in the percutaneous screw group during the first 7 postoperative days were significantly lower than those in the control group (p < 0.001). There was no significant difference between groups in VBI, VBA, and Cobb angle values during follow-up. There was no significant difference in screw placement accuracy between the groups and no patients required surgical revision. There was no significant difference between groups in overall satisfaction at the 2-year follow-up (p = 0.402). Working ability was insignificantly better in the percutaneous screw group; previous working position was achieved in 17 patients in this group and in 12 cases in the control group (p = 0.088).

Conclusions

This study confirms that the percutaneous transpedicular screw technique represents a viable option in the treatment of preselected thoracolumbar fractures. A significant reduction in blood loss, postoperative pain, and surgical time were the main advantages associated with this minimally invasive technique. Clinical, functional, and radiological results were at least the same as those achieved using the open technique after a 2-year follow-up. The short-term benefits of the percutaneous transpedicular screw technique are apparent, and long-term results have to be studied in other well-designed studies evaluating the theoretical benefit of the percutaneous technique and assessing whether the results of the latter are as durable as the ones achieved by open surgery.

Kyphopasty and vertebroplasty

Vertebroplasty and balloon kyphoplasty are percutaneous techniques performed under radioscopic control. They were initially developed for tumoral and osteoporotic lesions; indications were later extended to traumatology for the treatment of pure compression fracture. They are an interesting alternative to conventional procedures, which are often very demanding. The benefit of these minimally invasive techniques has been demonstrated in terms of alleviation of pain, functional improvement and reduction in both morbidity and costs for society. The principle of kyphoplasty is to restore vertebral body anatomy gently and progressively by inflating balloons and then reinforcing the anterior column of the vertebra with cement. In vertebroplasty, cement is introduced directly under pressure, without prior balloon inflation. Both techniques can be associated to minimally invasive osteosynthesis in certain indications. In our own practice, we preferably use acrylic cement, for its biomechanical properties and resistance to compression stress. We use calcium phosphate cement in young patients, but only associated to percutaneous osteosynthesis due to the risk of secondary correction loss. The evolution of these techniques depends on improving personnel radioprotection and developing new systems of vertebral expansion.

Resultados postoperatorios inmediatos y a largo plazo de un abordaje mini-invasivo para la corrección de escoliosis idiopática del adolescente

OBJETIVO: Analizar los resultados de una nueva técnica quirúrgica mínimamente invasiva (MIS, por el inglés "minimally invasive surgery") por vía posterior aislada para la corrección quirúrgica de la escoliosis idiopática del adolescente (EIA). MÉTODOS: Se comparan dos grupos de pacientes con EIA tipo 1A de Lenke, similares en cuanto a edad, género, ángulo de Cobb, ápex de la curva, rotación vertebral, cifosis torácica, niveles de fusión, tipo de instrumentación y seguimiento. El Grupo 1 fue tratado con la técnica mínimamente invasiva que describiremos y el Grupo 2, de forma convencional. Se analizaron el tiempo quirúrgico, la pérdida sanguínea intraoperatoria, los requerimientos analgésicos en el postoperatorio inmediato, la estancia hospitalaria, la tasa de mal posición de los tornillos, la pérdida de corrección, la tasa de pseudoartrosis y la movilización de implantes. RESULTADOS: En el Grupo 1 (MIS) la cirugía disminuyó significativamente el sangrado y presentó menor número de casos de tornillos mal posicionados en la concavidad que el grupo tratado de forma convencional; sin embargo la cirugía tuvo mayor duración. Ambos grupos tuvieron requerimientos analgésicos similares y la estancia hospitalaria no presentó diferencias. A largo plazo en ninguno de los dos grupos se encontraron casos de no-unión, pérdidas de corrección, ni movilización de los implantes. CONCLUSIONES: La técnica MIS demostró prolongación del tiempo quirúrgico y menores pérdidas hemáticas, sin disminuir los requerimientos analgésicos ni la estancia hospitalaria. La corrección inicial de la escoliosis por la convexidad disminuyó la incidencia de tornillos mal posicionados en la concavidad, no dio lugar a pérdidas de corrección, movilización de implantes y no-unión.

Posterior fixation of thoracolumbar burst fractures: is it possible to protect one segment in the lumbar region?

Background

The treatment for thoracolumbar burst fractures is controversial. The aim of this retrospective study was to compare intermediate-segment (IS) and long-segment (LS) instrumentation in the treatment for these fractures.

Methods

IS instrumentation was considered as pedicle fixation two levels above and one level below the fractured vertebra (infra-laminar hooks attached to lower vertebra with pedicle screws). LS instrumentation was done two levels above and two levels below the fractured vertebra. Among a total of 25 consecutive patients, Group 1 included ten patients treated by IS pedicle fixation, whereas Group 2 included fifteen patients treated by LS instrumentation.

Results

The measurements of local kyphosis (p = 0.955), sagittal index (p = 0.128), anterior vertebral height compression (p = 0.230) and canal diameter expansion (p = 0.839) demonstrated similar improvement at the final follow-up between the two groups. However, there was a significant difference (p < 0.05) between Group 1 and Group 2 regarding clinical outcome [Hannover scoring system, Oswestry disability questionnaire and the range of motion of the lumbar region compared to neutral (0°)].

Conclusions

The radiographic parameters were the same between the two groups. However, the clinical parameters demonstrated that IS instrumentation is a more effective management of thoracolumbar burst fractures.

Subphrenic hematoma after thoracoscopic discectomy: description of a very rare adverse event and review of the literature on complications

The authors describe a very rare and previously unreported complication of thoracoscopic discectomy. Endoscopic spine surgery has evolved as a safe and effective treatment, and thoracoscopic discectomy, in particular, provides several advantages over open approaches, although it can be associated with intraoperative or postoperative complications. The most frequently observed adverse events are intercostal neuralgia, retained disc fragments, durotomies, atelectasis, extensive bleeding, and emergency conversion to open thoracotomy for vascular injuries. Even rare complications, such as chylorrhea or brain hemorrhagic infarction, have been reported. Nonetheless, a literature review did not reveal any case of postoperative intraabdominal hematoma following thoracoscopic discectomy. A 43-year-old woman, with no history of hematological or vascular disorders or thoracic surgery, underwent a right-sided thoracoscopic discectomy for T11–12 disc herniation. No apparent surgical technique–related complications were encountered, but intermittently repeated difficulties with single-lung ventilation occurred. The resultant dysventilation allowed partial right lung reexpansion, along with increased abdominal pressure. The latter induced an upward ballooning of the right diaphragm with consequent obstruction of the surgical field of view, requiring constant and continuous pressure applied to the thoracic surface of the diaphragm via a metal fan retractor and thus counteracting the increased abdominal pressure. Postoperatively, a large subdiaphragmatic hematoma originating from a bleeding right inferior phrenic artery was diagnosed and required urgent endovascular occlusion. The patient made an uneventful recovery with conservative treatment. A very rare and previously unreported complication—that is, early subdiaphragmatic hematoma after thoracoscopic discectomy—is described here. The authors submit that conversion to an open approach is safer when persistent anesthesia-related complications are encountered in thoracoscopic discectomy.

Advances made in the treatment of thoracolumbar fractures: current trends and future directions

Thoracolumbar fractures are common injuries after blunt trauma and are accompanied with significant morbidity, including neurologic deficit. Parallel to the evolution of initial management during the past few years, efforts have been concentrated on determining clear indications for surgical treatment, as there is no agreement over superiority of conservative or operative treatment. Various classification systems have been used for identifying those injuries requiring surgical intervention. Moreover, novel trends in surgical techniques, including minimal invasive surgery, implants and rehabilitation protocols have provided new, promising aspects regarding the treatment and outcomes of thoracolumbar fractures. The present review focuses on these recent advances.