A retrospective comparative study of clinical efficacy of percutaneous short segment pedicle screw fixation with or without screwing of the fractured vertebra with O-arm navigation.

OBJECTIVE: To retrospectively analyze the short and long-term efficacies of O-arm-navigated percutaneous short segment pedicle screw fixation, with or without screwing of the fractured vertebra. METHODS: A total of 42 patients who underwent O-arm-navigated percutaneous short segment pedicle screw fixation for the treatment of thoracolumbar fractures from February 2015 to December 2018 were selected for analysis. The patients were divided into two groups according to the surgical intervention they received: Group A received percutaneous short segment pedicle screw fixation with screwing of the fractured vertebra and Group B received percutaneous short segment pedicle screw fixation without screwing of the fractured vertebra. Radiographic analysis included Cobb angles and percentage of anterior vertebral height (AVH%). Clinical functional outcomes were assessed using the visual analog scale (VAS) for back pain and the oswestry disability index (ODI) scores. RESULTS: No significant differences were observed in the operation time and intraoperative blood loss between the two groups (P > 0.05). The length of incision was statistically significantly different between the two groups (P < 0.05). There was no significant difference in Cobb angle and AVH% between the two groups before and after the surgery (P > 0.05). However, the Cobb angle and AVH% were both significantly larger in Group A than Group B at the final follow-up (P < 0.05). In terms of clinical outcomes, there were no statistically significant differences in VAS and ODI scores between the two groups (P > 0.05). CONCLUSION: In the short term, both minimally invasive treatments were safe and effective in treating thoracolumbar fracture. Although there was significant difference between the two groups in Cobb angle and vertebral body height at the last follow-up, the difference was small. Therefore, these specific parameters will be an important outcome measure in further investigations.

Predictors of adverse events after percutaneous pedicle screws fixation in patients with single-segment thoracolumbar burst fractures.

BACKGROUND: Percutaneous pedicle screw fixation (PPSF) is the primary approach for single-segment thoracolumbar burst fractures (TLBF). The healing angle at the thoracolumbar junction is one of the most significant criteria for evaluating the efficacy of PPSF. Therefore, the purpose of this study was to analyze the predictors associated with the poor postoperative alignment of the thoracolumbar region from routine variables using a support vector machine (SVM) model. METHODS: We retrospectively analyzed patients with TLBF operated at our academic institute between March 1, 2014 and December 31, 2019. Stepwise logistic regression analysis was performed to assess potential statistical differences between all clinical and radiological variables and the adverse events. Based on multivariate logistic results, a series of independent risk factors were fed into the SVM model. Meanwhile, the feature importance of radiologic outcome for each parameter was explored. The predictive performance of the SVM classifier was evaluated using the area under the receiver operating characteristic curve (AUC), accuracy (ACC) and confusion matrices with 10-fold cross-validation, respectively. RESULTS: In the recruited 150 TLBFs, unfavorable radiological outcomes were observed in 53 patients (35.33%). The relationship between osteoporosis (p = 0.036), preoperative Cobb angle (p = 0.001), immediate postoperative Cobb angle (p = 0.029), surgically corrected Cobb angle (p = 0.001), intervertebral disc injury (Score 2 p = 0.001, Score 3 p = 0.001), interpedicular distance (IPD) (p = 0.001), vertebral body compression rate (VBCR) (p = 0.010) and adverse events was confirmed by univariate regression. Thereafter, independent risk factors including preoperative Cobb angle, the disc status and IPD and independent protective factors surgical correction angle were identified by multivariable logistic regression. The established SVM classifier demonstrated favorable predictive performance with the best AUC = 0.93, average AUC = 0.88, and average ACC = 0.87. The variables associated with radiological outcomes, in order of correlation strength, were intervertebral disc injury (42%), surgically corrected Cobb angle (25%), preoperative Cobb angle (18%), and IPD (15%). The confusion matrix reveals the classification results of the discriminant analysis. CONCLUSIONS: Critical radiographic indicators and surgical purposes were confirmed to be associated with an unfavorable radiographic outcome of TLBF. This SVM model demonstrated good predictive ability for endpoints in terms of adverse events in patients after PPSF surgery.

The History and Development of the Percutaneous Pedicle Screw (PPS) System.

Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) using the SEXTANT® system (Medtronic) featured the first generation of commercially available percutaneous pedicle screw (PPS) system in 2001. The innovative system has since become standard instrumentation used worldwide, and PPS is now used for long-segment minimally invasive surgery (MIS) spinal fixation from the thoracic spine to the pelvis for pathological conditions. PPS systems have been developed for approximately 20 years for the purpose of improving minimally invasive techniques, safety of instrumentation, and ease of use. The third-generation PPS systems established the insertion technique, and the development of the fourth-generation PPS systems have made great strides in minimizing the number of steps in the operative procedure. In the future, PPS systems are expected to continue making use of the latest technological advancements and to develop further with the aim of ensuring greater safety, reducing operator stress, and preventing complications such as insertion errors and infection. In this review article, we describe the historical evolution from the first-generation PPS system to the current PPS systems used today.

Minimally Invasive Spinal Treatment (MIST)-A New Concept in the Treatment of Spinal Diseases: A Narrative Review.

In the past two decades, minimally invasive spine surgery (MISS) techniques have been developed for spinal surgery. Historically, minimizing invasiveness in decompression surgery was initially reported as a MISS technique. In recent years, MISS techniques have also been applied for spinal stabilization techniques, which were defined as minimally invasive spine stabilization (MISt), including percutaneous pedicle screws (PPS) fixation, lateral lumbar interbody fusion, balloon kyphoplasty, percutaneous vertebroplasty, cortical bone trajectory, and cervical total disc replacement. These MISS techniques typically provide many advantages such as preservation of paraspinal musculature, less blood loss, a shorter operative time, less postoperative pain, and a lower infection rate as well as being more cost-effective compared to traditional open techniques. However, even MISS techniques are associated with several limitations including technical difficulty, training opportunities, surgical cost, equipment cost, and radiation exposure. These downsides of surgical treatments make conservative treatments more feasible option. In the future, medicine must become "minimally invasive" in the broadest sense-for all patients, conventional surgeries, medical personnel, hospital management, nursing care, and the medical economy. As a new framework for the treatment of spinal diseases, the concept of minimally invasive spinal treatment (MIST) has been proposed.

Intraoperative CT-guided navigation versus fluoroscopy for percutaneous pedicle screw placement in 192 patients: a comparative analysis.

BACKGROUND: Percutaneous pedicle screw (PPS) placement is a key step in several minimally invasive spinal surgery (MISS) procedures. Traditional technique for PPS makes use of C-arm fluoroscopy assistance (FA). More recently, newer intraoperative imaging techniques have been developed for PPS, including CT-guided navigation (CTNav). The aim of this study was to compare FA and CTNav techniques for PPS with regard to accuracy, complications, and radiation dosage. MATERIALS AND METHODS: A total of 192 patients with degenerative lumbar spondylolisthesis and canal stenosis who underwent MISS posterior fusion ± interbody fusion through transforaminal approach (TLIF) were retrospectively reviewed. Pedicle screws were placed percutaneously using either standard C-arm fluoroscopy guidance (FA group) or CT navigation (CTNav group). Intraoperative effective dose (ED, mSv) was measured. Screw placement accuracy was assessed postoperatively on a CT scan using Gertzbein and Robbins classification (grades A-E). Oswestry disability index (ODI) and visual analog scale (VAS) scores were compared in both groups before and after surgery. RESULTS: A total of 101 and 91 procedures were performed with FA (FA group) and CTNav approach (CTNav group), respectively. Median age was 61 years in both groups, and the most commonly treated level was L4-L5. Median ED received from patients was 1.504 mSv (0.494-4.406) in FA technique and 21.130 mSv (10.840-30.390) in CTNav approach (p < 0.001). Percentage of grade A and B screws was significantly higher for the CTNav group (96.4% versus 92%, p < 0.001), whereas there were 16 grade E screws in the FA group and 0 grade E screws in the CTNav group (p < 0.001). A total of seven and five complications were reported in the FA and CTNav group, respectively (p = 0.771). CONCLUSIONS: CTNav technique increases accuracy of pedicle screw placement compared with FA technique without affecting operative time. Nevertheless, no significant difference was noted in terms of reoperation rate due to screw malpositioning between CTNav and FA techniques. Radiation exposure of patients was significantly higher with CTNav technique. LEVEL OF EVIDENCE: Level 3.

Impairment-driven cancer rehabilitation in patients with neoplastic spinal cord compression using minimally invasive spine stabilization.

BACKGROUND: Neoplastic spinal cord compression is a cause of severe disability in cancer patients. To prevent irreversible paraplegia, a structured strategy is required to address the various impairments present in cancer patients. In this study, we aimed to identify the status where rehabilitation with minimally invasive spine stabilization (MISt) effectively improves ADL. METHODS: We retrospectively reviewed 27 consecutive patients with neoplastic spinal compression who were treated with MISt. We classified the impairments of patients through our multidisciplinary tumor board based on spine-specific factors, skeletal instability, and tumor growth. The neurological deficits, progress of pathological fracture, incidence of vertebral collapse, and postoperative implant failure were examined. Changes of the Barthel index (BI) scores before and after surgery were investigated throughout the clinical courses. RESULTS: The average duration to ambulation was 7.19 ± 11 days, and we observed no collapse or progression of paralysis except in four cases of complete motor paraplegia before the surgery. Neurological deficiency was improved to or maintained at Frankel's grade E in 16 patients, remained unchanged in 6 patients (in grades B, C, D), and worsened in 5 patients. BI score comparisons before and after surgery in all patients showed statistically significant increments (p < 0.05). On further analysis, we noted good functional prognosis in patients capable of ambulation within 7 days (p < 0.05) and in patients who could survive longer than 3 months after the surgery (p < 0.05). CONCLUSIONS: In various cancer patients with neoplastic spinal cord compression, skeletal instability as the primary impairment is a good indication for MISt, as the patients showed early ambulation with improved BI scores.

Modified mini-open SRS-Schwab grade 4 osteotomy combined with percutaneous pedicle screws fixation in post-traumatic thoracolumbar kyphosis.

BACKGROUND: We aimed to analyze the clinical results of Schwab grade 4 osteotomy combined with percutaneous pedicle screws (PPS) fixation for treatment of post-traumatic thoracolumbar kyphosis (PTK). METHODS: Thirty four patients with PTK (group A) were included in our study. The average age was 54.9 ± 3.3 years. All patients had severe back pain with 8.6 ± 1.3 VAS scores. The affected level was T12 in 16 patients and L1 in 18 patients. The average preoperative regional kyphosis angle (RKA) was 30.7 ± 6.00. Three patients had neurological dysfunction with ASIA grade D. All patients underwent Schwab grade 4 osteotomy combined with PPS fixation. The control group (Group B) were 26 PTK patients treated with Schwab grade 4 osteotomy and open pedicle screws fixation in our institution. RESULTS: Operation time in groups A and B was 280 ± 50 min and 210 ± 30 min, respectively (P < 0.05). Estimated blood loss in groups A and B was 310 ± 70 ml and 630 ± 40 ml, respectively (P < 0.05). No cerebral spinal fluid leakage, segmental nerve function damage, and other complications observed during and after the operations in both groups. RKA, SVA, and LL improved significantly after surgery in both groups (P < 0.05). The average correction rate in groups A and B was 64.5 and 66.3% (P > 0.05). CT showed that the misplacement rate in groups A and B was 5.5 and 6.6% (P > 0.05). The average follow-up in groups A and B was 25.2 ± 7.6 months and 30.6 ± 2.7 months. No fracture and other complications were observed in both groups. Solid bone fusion was showed in all cases at 6 months follow-up. In groups A and B, all patients with preoperative neurological dysfunction recovered to ASIA grade E at the last follow-up. The VAS score of back pain improved significantly from 8.6 ± 1.3 to 1.6 ± 1.0 at the last follow-up in group A (P < 0.05), while it improved significantly from 8.3 ± 1.2 to 3.0 ± 1.1 at the last follow-up in group B (P < 0.05). VAS of back pain was better in group A than that in group B. CONCLUSION: Schwab grade 4 osteotomy combined with percutaneous pedicle screws fixation is a minimally invasive, safe and effective method for PTK treatment.

[Comparison of percutaneous pedicle screw placement under O-arm navigation with traditional percutaneous pedicle screw placement in patients with thoracolumbar fractures without neurological symptoms].

Objective: To investigate the accuracy and clinical efficacy of percutaneous pedicle screw placement under O-arm navigation and traditional fluoroscopy in patients with thoracolumbar fractures without neurological symptoms. Methods: From July 2016 to July 2018, 72 patients with thoracolumbar fractures in Peking University International Hospital without neurological symptoms were divided into two groups, group A and group B. In group A, 36 patients underwent the surgery of percutaneous pedicle screw implantation under traditional fluoroscopy and 168 pedicle screws were inserted. In group B, 36 patients underwent the surgery of percutaneous pedicle screw implantation under O-arm guided fluoroscopy and 164 pedicle screws were inserted by the same surgeon. The general condition, operation condition, radiation dose, fluoroscopy time of single screw, screw placement time and accuracy, visual analogue score (VAS) score, Oswestry dysfunction index (ODI), kyphosis Cobb's angle, anterior edge height of 1 week and 6 months after surgery were compared. The data were compared with paired t test between the two groups. Results: There was no significant differences between the two groups in general condition, intraoperative blood loss, length of hospital stay, VAS, ODI, kyphosis Cobb's angle, and anterior edge height of the injured vertebra (all P>0.05). The operation time was (99±14) min in group A and (75±10) min in group B, the average screw setting time was (15.8±2.6) min in group A and (11.8±3.3) min in group B, the fluoroscopy time of each screw was (38.0±2.0) s in group A and (28.5±2.8) s in group B, the radiation dose of each surgery was (563±163) cGy/cm(2) in group A and (378±70) cGy/cm(2) in group B; the above-mentioned data of group A were all superior to those in group B and the differences between the two groups were all statistically significant (t=8.48, 5.73, 16.30, 6.25, all P<0.05). Rampersaud grading in group A was better than group B, and the differences between the two groups was statistically significant(χ(2)=12.2, P<0.05). Conclusion: The O-arm navigation system could not only provide high-definition navigation images and achieve high-precision navigation operations, which is more accurate than traditional pedicle screws placement, but also contribute to the reconstruction of spinal stability and reduce radiation dose, pedicle screws placement and operating time.

A new method to precisely control the depth of percutaneous screws into the pedicle by counting the rotation number of the screw with low radiation exposure: technical note.

STUDY DESIGN: Technique note. OBJECTIVES: To report a new method for precisely controlling the depth of percutaneous pedicle screws (PPS)-without radiation exposure to surgeons and less fluoroscopy exposure to patients than with conventional methods. PPS is widely used in minimal invasive spine surgery; the advantages include reduced muscle damage, pain, and hospital stays. However, placement of PPS demands repeated checking with fluoroscopy. Thus, radiation exposure is considerable for both surgeons and patients. METHODS: The PPS depth was determined by counting rotations of the screws. The distance between screw threads can be measured for particular screws; thus, full rotations of the PPS results in the screw advancing in the pedicle the distance between screw threads. To fully insert screws into the pedicle, the number of full rotations is equal to the number of threads in the PPS. RESULTS: We applied this technique in 58 patients with thoracolumbar fracture. The position and depth of the screws was checked during the operation with the C-arm and after operation by anteroposterior X-ray film or computed tomography. No additional procedures were required to correct the screws; we observed no neurological deficits or malpositioning of the screws. In the screw placement procedure, the radiation exposure for surgeons is zero, and the patient is well protected from extensive radiation exposure. CONCLUSIONS: This method of counting rotation of screws is a safe way to precisely determine the depth of PPS in the placement procedure. LEVEL OF EVIDENCE: IV.

Comparison of serum markers for muscle damage, surgical blood loss, postoperative recovery, and surgical site pain after extreme lateral interbody fusion with percutaneous pedicle screws or traditional open posterior lumbar interbody fusion.

BACKGROUND: The benefits of extreme lateral interbody fusion (XLIF) as a minimally invasive lumbar spinal fusion treatment for lumbar degenerative spondylolisthesis have been unclear. We sought to evaluate the invasiveness and tolerability of XLIF with percutaneous pedicle screws (PPS) compared with traditional open posterior lumbar interbody fusion (PLIF). METHODS: Fifty-six consecutive patients underwent open PLIF and 46 consecutive patients underwent single-staged treatment with XLIF with posterior PPS fixation for degenerative lumbar spondylolisthesis, and were followed up for a minimum of 1 year. We analyzed postoperative serum makers for muscle damage and inflammation, postoperative surgical pain, and performance status. A Roland-Morris Disability Questionnaire (RDQ) and Oswestry Disability Index (ODI) were obtained at the time of hospital admission and 1 year after surgery. RESULTS: Intraoperative blood loss (51 ± 41 ml in the XLIF/PPS group and 206 ± 191 ml in the PLIF group), postoperative WBC counts and serum CRP levels in the XLIF/PPS group were significantly lower than in the PLIF group. Postoperative serum CK levels were significantly lower in the XLIF/PPS group on postoperative days 4 and 7. Postoperative recovery of performance was significantly greater in the XLIF/PPS group than in the PLIF group from postoperative days 2 to 7. ODI and visual analog scale (VAS) score (lumbar) 1 year after surgery were significantly lower in the XLIF/PPS group compared with the PLIF group. CONCLUSIONS: The XLIF/PPS procedure is advantageous to minimize blood loss and muscle damage, with consequent earlier recovery of daily activities and reduced incidence of low back pain after surgery than with the open PLIF procedure.

Pars Interarticularis Fractures Treated with Minimally Invasive Surgery: A Literature Review.

Recurrent stress on the isthmic pars interarticularis often leads to profound injury and symptom burden. When conservative and medical management fail, there are various operative interventions that can be used. The current review details the common clinical presentation and treatment of pars injury, with a special focus on the emerging minimally invasive procedures used in isthmic pars interarticularis repair. PubMed and Google Scholar database literature reviews were conducted. The keywords and phrases that were searched include but were not limited to; "history of spondylolysis", "pars interarticularis", "pars defect", "conventional surgical repair of pars", and "minimally invasive repair of pars". The natural history, conventional presentation, etiology, risk factors, and management of pars interarticularis injury are discussed by the authors. The surgical interventions described include the Buck's repair, Morscher Screw-Hook repair, Scott's Wiring technique, and additional pedicle screw-based repairs. Minimally invasive techniques are also reviewed, including the Levi technique. Surgical intervention has been proven to be safe and effective in managing pars interarticularis fractures. However, minimally invasive techniques often provide additional benefit to patients such as reducing damage of surrounding structures, decreasing postoperative pain, and limiting the time away from sports and other activities.

Short-segment percutaneous fusion versus open posterior fusion with screw in the fractured vertebra for thoracolumbar junction burst vertebral fracture treatment.

Objectives: The treatment options for thoracolumbar junction burst fractures remain a topic of controversy. Short-segment percutaneous fixation (SSPF) and short-segment open fixation including the fractured level (SSOFIFL) are both viable procedures for managing these fractures. At present, there is a lack of evidence in the literature demonstrating the absolute superiority of one treatment over the other. This study aimed to compare these two surgical strategies with a focus on radiological and clinical outcomes. Materials and Methods: This retrospective case-control multicenter analysis involved patients with A3 and A4 vertebral fractures at the thoracolumbar junction (T11-L2) who underwent surgical treatment with either SSPF or SSOFIFL in the participating centers. Clinical outcomes were measured using the Oswestry Disability Index and visual analogue scale (VAS) both pre- and postoperatively. Radiological outcomes included kyphotic deformity (KD), anterior vertebral body height (AVBH), segmental kyphosis, and sagittal alignment parameters. Results: A total of 156 patients were enrolled in the study, with 81 patients in Group A (SSPF) and 75 patients in Group B (SSOFIFL). Group B demonstrated better correction of KD (Group B: 3.4 ± 2.7° vs. Group A: 8.3 ± 3.2°, P = 0.003), AVBH, and sagittal alignment. A minor loss of correction was observed in Group B with respect to Group A (0.9 ± 1.7° vs 4.3° ± 2.1°, P = 0.043). Blood losses were lower in Group A (78 ± 15 min vs. 118 ± 23 min, P = 0.021) as well as during surgery (121.3 ± 34 mL vs. 210.2 ± 52 mL, P = 0.031), but the post-operative hemoglobin levels were comparable between the two groups. Conclusion: SSOFIFL appears to show a major amount of KD correction and prevent loss of correction. This technique should be the preferred choice whenever possible. However, SSPF can be considered a valid alternative for damage control in polytrauma patients and fractures with low KD.

[Percutaneous pedicle screw anchored vertebral augmentation for the treatment of Kümmell disease without neurological symptoms].

OBJECTIVE: To explore the clinical effect of percutaneous pedicle screw anchored vertebral augmentation(PPSAVA) in the treatment of asymptomatic Kümmell disease without neurological symptoms. METHODS: The clinical data of 20 patients with Kümmell disease without neurological symptoms treated with PPSAVA in our hospital from January 2019 to December 2021 were analyzed retrospectively, including 5 males and 15 females, aged 56 to 88 (74.95±9.93) years old. and the course of disease was 7 to 60 days with an average of (21.35±14.46) days. All patients were treated with PPSAVA. The time of operation, the amount of bone cement injected and the leakage of bone cement were recorded. The visual analogue scale(VAS), Oswestry disability index(ODI), vertebral body angle(VBA), anterior edge height and midline height of vertebral body were compared among the before operation, 3 days after operation and during the final follow-up. The loosening and displacement of bone cement were observed during the final follow-up. RESULTS: All the 20 patients completed the operation successfully. The operation time was 30 to 56 min with an average of (41.15±7.65) min, and the amount of bone cement injection was 6.0 to 12.0 ml with an average of (9.30±1.49) ml. Bone cement leakage occurred in 6 cases and there were no obvious clinical symptoms. The follow-up time was 6 to 12 months with an average of (8.43±2.82) months. The VBA, anterior edge height and midline height of of injured vertebral body were significantly improved 3 days after operation and the final follow-up(P<0.05), and the VBA, anterior edge height and midline height of of injured vertebral body were lost in different degrees at the final follow-up (P<0.05). The VAS and ODI at 3 days after operation and at the final follow-up were significantly lower than those at preoperatively(P<0.05), but the VAS score and ODI at the final follow-up were not significantly different from those at 3 d after operation(P>0.05). At the last follow-up, no patients showed loosening or displacement of bone cement. CONCLUSION: PPSAVA is highly effective in treating Kümmell disease without neurological symptoms, improving patients' pain and functional impairment, and reducing the risk of cement loosening and displacement postoperatively.

Positioning accuracy and facet joints violation after percutaneous pedicle screws placement with robot-assisted versus fluoroscopy-guided technique: Systematic review and meta-analysis.

Introduction: Minimally invasive spine surgery became the gold standard for the treatment of many spinal diseases. Only a few comparative studies were performed regarding the superiority of robotic-assisted (RA) surgery over fluoroscopic guidance (FG) surgery during percutaneous pedicle screws placement. Therefore, the aim of the present study was to conduct a systematic literature review and meta-analysis to evaluate the accuracy and potential advantages of RA compared with FG. Material and Methods: This study is a systematic literature review conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. The review questions were formulated following the PICO scheme. Measured outcomes were presented using Forest plots. Heterogeneity among the included studies was assessed using the χ2 test, and the I2 statistic was utilized to estimate the proportion of total variation among the studies. A value exceeding 50% was considered indicative of substantial heterogeneity. Results: Seven studies that met inclusion criteria were finally included in this meta-analysis. These seven studies include: 447 patients, 228 patients (931 screws) treated with robotic guide, and 219 patients (767 pedicle screws) using fluoroscopic guide, with a mean age of 55.2. The percentages of clinically acceptable screws were 94.3% in the robot-assisted group and 89% in the fluoroscopic guided group. The percentages of non-acceptable screws were 5.7% in the robot-assisted group and 11% in the fluoroscopic-guided group. Discussion: Significant differences were observed between the two groups in terms of radiographic and clinical outcomes, with the robotic-assisted pedicle screw group exhibiting longer operative times. Robot technology serves as a valuable tool for assisting surgeons in challenging scenarios such as anatomical variants or patients with spinal deformities, ensuring accurate screw placement. Conclusion: The accuracy of pedicle screw placement with robotic technology is higher than with FG. In fact, the robotic approach allows significantly lower complication rates, fewer cases of violation of the proximal articular facet, less intraoperative exposure to radiation, even if it requires longer surgical times than the FG technique.

Radiological Assessment of Postoperative Paraspinal Muscle Changes After Lumbar Interbody Fusion With or Without Minimally Invasive Techniques.

STUDY DESIGN: Retrospective cohort study. BACKGROUND: Percutaneous pedicle screws (PPS) have the advantage of being able to better preserve the paraspinal muscles when compared with a traditional open approach. However, the nature of changes in postoperative paraspinal muscle after damage by lumbar fusion surgery has remained largely unknown. It is clinically important to clarify and compare changes in paraspinal muscles after the various surgeries. OBJECTIVE: (1) To determine postoperative changes of muscle density and cross-sectional area using computed tomography (CT), and (2) to compare paraspinal muscle changes after posterior lumbar interbody fusion (PLIF) with traditional open approaches and minimally invasive lateral lumbar interbody fusions (LLIF) with PPS. METHODS: We included data from 39 consecutive female patients who underwent open PLIF and 23 consecutive patients who underwent single-staged treatment with LLIF followed by posterior PPS fixation at a single level (L4-5). All patients underwent preoperative, 6 months postoperative, and 1-year postoperative CT imaging. Measurements of the cross-sectional area (CSA) and muscle densities of paraspinal muscles were obtained using regions of interest defined by manual tracing. RESULTS: We did not find any decrease of CSA in any paraspinal muscles. We did find a decrease of muscle density in the multifidus at 1 year after surgery in patients in the PILF group, but not in those in LLIF/PPS group. CONCLUSIONS: One year after surgery, a significant postoperative decrease of muscle density of the multifidi was observed only in patients who underwent open PLIF, but not in those who underwent LLIF/PPS.

Computed Tomography Evaluation of Percutaneous Pedicle Screws Inserted during Minimally Invasive Transforaminal Lumbar Interbody Fusion: Long-term Follow-up Results of Screw Violation.

Background: To evaluate the accuracy of percutaneous pedicle screw (PPS) insertion in degenerative lumbar disease treated with minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) and to analyze risk factors and long-term clinical outcomes of screw violation. Methods: Sixty-two consecutive patients (262 screws) were included. Based on postoperative computed tomography (CT) axial images, a PPS that perforated out of the pedicle was classified into a violation group, while screws surrounded by pedicular cortical bone were classified into a correct group. A logistic regression model was used for risk factor analysis of violation. We also observed the long-term clinical outcomes using the Oswestry disability index and visual analog scale. Results: Of the 262 screws, 14 (5.3%) were considered to be violated (10 medial violations and 4 lateral violations). All violations of S1 and L5 were in the medial direction. In contrast, entire violations of L4 were always lateral and of the 2 violations of L3, one was lateral and the other was medial. There were no cases of superior or inferior violation. The mean pedicle convergence angle (CA) was significantly higher in the violation group (mean ± standard deviation, 27.0° ± 6.2°) than in the correct group (21.7° ± 5.4°). There were no significant differences according to vertebral rotational angle, body mass index, bone mineral density, and surgical timing (learning curve) between the two groups. Logistic regression analyses demonstrated that a high CA was a significant risk factor for pedicle wall violation (p = 0.002). There were no significant differences in clinical or radiographic results between the two groups in 60 patients who were followed up for more than 1 year and in 40 patients who were followed up for more than 5 years. There were 2 patients who required reoperation to replace a screw due to leg pain. Conclusions: With PPS insertion during MI-TLIF, the rate of pedicle violation was 5.3% (14/262). An understanding of the anatomical characteristics of each vertebra and the unique structures of the patient is essential to prevent pedicle violations. Even in the violation group, PPS fixation was found to be a safe and useful procedure with successful long-term radiographic and clinical outcomes.

Patient-Reported Outcomes of Minimally Invasive versus Open Transforaminal Lumbar Interbody Fusion for Degenerative Lumbar Disc Disease: A Prospective Comparative Cohort Study.

Background: Comparative outcomes of minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) and traditional open TLIF (O-TLIF) for degenerative lumbar disc disease have been poorly studied. The purpose of this study was to prospectively compare the outcomes between MI-TLIF and O-TLIF for patients with a degenerative disc disease, focusing on the functional capacity of patients in daily life. Methods: A prospective cohort study was performed, comparing 54 patients who underwent O-TLIF and 55 patients who underwent MI-TLIF with a follow-up of 4 years. Clinical evaluation was performed using the Oswestry Disability Index (ODI), 36-item short form survey (SF-36), and a visual analog scale for pain (VAS pain). Radiological evaluation was also performed. Results: At the final follow-up, compared with O-TLIF, MI-TLIF was associated with significantly better intraoperative results, including similar operative time (p = 0.246), lower estimated blood loss (p = 0.001), and shorter hospital stay (p = 0.001). The final ODI score was significantly better in the MI-TLIF group (p = 0.031). The SF-36-physical (p = 0.023) and VAS pain (p = 0.024) scores were significantly better in the MI-TLIF group. There was no significant difference in the fusion rate (p = 0.747). Conclusions: The MI-TLIF technique is an effective and safe procedure for degenerative lumbar disc disease. Compared to traditional O-TLIF, MI-TLIF was associated with less disability and higher quality of life, with a low rate of intraoperative and postoperative complications.

Assessing Procedural Accuracy in Lateral Spine Surgery: A Retrospective Analysis of Percutaneous Pedicle Screw Placement with Intraoperative CT Navigation.

Percutaneous pedicle screws (PPSs) are commonly used in posterior spinal fusion to treat spine conditions such as trauma, tumors, and degenerative diseases. Precise PPS placement is essential in preventing neurological complications and improving patient outcomes. Recent studies have suggested that intraoperative computed tomography (CT) navigation can reduce the dependence on extensive surgical expertise for achieving accurate PPS placement. However, more comprehensive documentation is needed regarding the procedural accuracy of lateral spine surgery (LSS). In this retrospective study, we investigated patients who underwent posterior instrumentation with PPSs in the thoracic to lumbar spine, utilizing an intraoperative CT navigation system, between April 2019 and September 2023. The system's methodology involved real-time CT-based guidance during PPS placement, ensuring precision. Our study included 170 patients (151 undergoing LLIF procedures and 19 trauma patients), resulting in 836 PPS placements. The overall PPS deviation rate, assessed using the Ravi scale, was 2.5%, with a notably higher incidence of deviations observed in the thoracic spine (7.4%) compared to the lumbar spine (1.9%). Interestingly, we found no statistically significant difference in screw deviation rates between upside and downside PPS placements. Regarding perioperative complications, three patients experienced issues related to intraoperative CT navigation. The observed higher rate of inaccuracies in the thoracic spine suggests that various factors may contribute to these differences in accuracy, including screw size and anatomical variations. Further research is required to refine PPS insertion techniques, particularly in the context of LSS. In conclusion, this retrospective study sheds light on the challenges associated with achieving precise PPS placement in the lateral decubitus position, with a significantly higher deviation rate observed in the thoracic spine compared to the lumbar spine. This study emphasizes the need for ongoing research to improve PPS insertion techniques, leading to enhanced patient outcomes in spine surgery.

Reduction in Radiation Exposure in Minimally Invasive Pedicle Screw Placement Using a Tubular Retractor: A Pilot Study.

BACKGROUND AND OBJECTIVES: Percutaneous pedicle screw (PPS) placement is a minimally invasive spinal procedure that has been rapidly adopted over the last decade. However, PPS placement has elicited fear of increased radiation exposure from some surgeons, medical staff, and patients. This is because PPS placement is performed using a K-wire, and the operator must perform K-wire insertion into the pedicle under fluoroscopy. In order to prevent erroneous insertion, there are many occasions when direct insertion is required during radiation exposure, and the amount of radiation exposure to hands and fingers in particular increases. Although these problems are being addressed by navigation systems, these systems are still expensive and not widely available. Attempts have been made to address this situation using instrumentation commonly used in spinal surgery. First, it was considered to visualize anatomical bone markers using a tubular retractor and a microscope. In addition, the use of a self-drilling pin was adopted to locate the pedicle in a narrower field of view. Based on these considerations, a minimally invasive and highly accurate pedicle screw placement technique was developed while avoiding direct radiation exposure. This study evaluated radiation exposure and accuracy of pedicle screw placement using this new procedure in one-level, minimally invasive, transforaminal lumbar interbody fusion (MIS-TLIF). MATERIALS AND METHODS: Data were collected retrospectively to review pedicle screw placement in single-level MIS TLIFs using a tubular retractor under a microscope. The total fluoroscopy time, radiation dose, and screw placement accuracy were reviewed. Extension of operating time was also evaluated. RESULTS: Twenty-four patients underwent single-level MIS TLIFs, with placement of 96 pedicle screws. There were 15 females and 9 males, with an average age of 64.8 years and a mean body mass index of 25.5 kg/m2. The mean operating time was 201.8 min. The mean fluoroscopic time was 26.8 s. The mean radiation dose of the area dose product was 0.0706 mGy∗m2. The mean radiation dose of air kerma was 6.0 mGy. The mean radiation dose of the entrance skin dose was 11.31 mGy. Postoperative computed tomography scans demonstrated 93 pedicle screws confined to the pedicle (97%) and three pedicle screw breaches (3.2%; two lateral, one medial). A patient with screw deviation of the medial pedicle wall developed right-foot numbness necessitating reoperation. There were no complications after reoperation. The average added time with this combined procedure was 39 min (range 16-69 min) per patient. CONCLUSIONS: This novel pedicle screw insertion technique compares favorably with other reports in terms of radiation exposure reduction and accuracy and is also useful from the viewpoint of avoiding direct radiation exposure to hands and fingers. It is economical because it uses existing spinal surgical instrumentation.

Posterior Percutaneous Pedicle Screws Fixation Versus Open Surgical Instrumented Fusion for Thoraco-Lumbar Spinal Metastases Palliative Management: A Systematic Review and Meta-analysis.

Background: Surgical palliative treatment of spinal metastases (SM) could influence the quality of life (QoL) in cancer patients, since the spine represents the most common site of secondary bony localization. Traditional open posterior instrumented fusion (OPIF) and Percutaneous pedicle screw fixation (PPSF) became the main surgical treatment alternatives for SM, but in Literature there is no evidence that describes the absolute superiority of one treatment over the other. Materials and Methods: This is a systematic review and meta-analysis of comparative studies on PPSF versus OPIF in patients with SM, conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The outcomes of interest were: complications, blood loss, infections, mortality, pain and also the Quality of Life (QoL). Results: There were a total of 8 studies with 448 patients included in the meta-analyses. Postoperative complications were more frequent in OPIF (odds ratio of 0.48. 95% CI, 0.27 to 0.83; p= 0.01), PPFS was associated with blood loss (odds ratio -585.70. 95% IC, -848.28 to -323.13.69; p< 0.0001) and a mean hospital stay (odds ratio -3.77. 95% IC, -5.92 to -1.61; p= 0.0006) decrease. The rate of infections was minor in PPFS (odds ratio of 0.31. 95% CI, 0.12 to 0.81; p= 0.02) whereas the occurrence of reinterventions (0.76. 95% CI, 0.25 to 2.27; p= 0.62) and the mortality rate was similar in both groups (odds ratio of 0.79. 95% CI, 0.40 to 1.58; p= 0.51). Finally, we also evaluated pre and post-operative VAS and the meta-analysis suggested that both techniques have a similar effect on pain. Discussion and Conclusion: The PPSF treatment is related with less complications, a lower rate of infections, a reduction in intraoperative blood loss and a shorter hospital stay compared to the OPIF treatment. However, further randomized clinical trials could confirm the results of this meta-analysis and provide a superior quality of scientific evidence.