CT navigation in spinal deformity surgery

Does intraoperative CT navigation increase the accuracy of pedicle screw placement in pediatric spinal deformity surgery? A systematic review and meta-analysis.

Study design/methodsReview article.ObjectivesThe goal of this article is to review the available evidence for computerized navigation and robotics as an accuracy improvement tool for spinal deformity surgery, as well as to consider potential complications, impact on clinical outcomes, radiation exposure, and costs.Summary of background data/resultsPedicle screw and rod construct are widely utilized for posterior spinal fixation in spinal deformity correction. Freehand placement of pedicle screws has long been utilized, although there is variable potential for inaccuracy depending on surgeon skill and experience. Malpositioned pedicle screws may have significant clinical implications ranging from nerve root irritation, inadequate fixation, CSF leak, perforation of the great vessels, or spinal cord damage. Computer-based navigation and robotics systems were developed to improve pedicle screw insertion accuracy and consistency, and decrease the risk of malpositioned pedicle fixation. The available evidence suggests that computer-based navigation and robotic-assisted guidance systems for pedicle cannulation are at least equivalent, and in several reports superior, to freehand techniques in terms of accuracy. CT and robotic navigation systems do appear to decrease radiation exposure to the operative team in some reports. Published reports do indicate longer operative times with use of robotic navigation compared with traditional freehand techniques for pedicle screw placement. To date, there is no conclusive evidence that use of CT or robotic navigation has any measurable impact on patient outcomes or overall complication reduction. There are theoretical advantages with robotic and CT navigation in terms of both speed and accuracy for severe spinal deformity or complex revision cases, however, there is a need for studies to investigate this technology in these specific cases. There is no evidence to date demonstrating the cost effectiveness of CT or robotic navigation as compared with traditional pedicle cannulation techniques.ConclusionsThe review of available evidence suggests that computer-based navigation and robotic-assisted guidance systems for pedicle cannulation are at least equivalent, and in several reports superior, to freehand techniques in terms of radiographic accuracy. There is no current clinical evidence that the use of navigation or robotic techniques leads to improved patient outcomes or decreased overall complications or reoperation rates, and the use of these systems may substantially increase surgical costs.Level of evidenceV.

A consecutive case series. To determine the revision rate for pedicle screws placed using intraoperative CT and image-guided navigation in children 10 years or younger. Screws are frequently used for spinal instrumentation in young children, although this is only by physician-directed use. This is a multicenter retrospective study of patients aged 10 years or younger, who underwent spinal screw instrumentation with image-guided navigation. We hypothesized that intraoperative navigation would result in a high rate of accuracy for screw placement. Between 2007 and 2013, 130 pedicle and 7 lateral mass screws were placed in 16 consecutive patients undergoing a total of 17 surgeries at 2 institutions. Mean age at surgery was 6.9 years (range, 0.8-10.9 y). Screws were placed using an open technique with intraoperative CT (O-arm) and image-guided navigation (Stealth). Procedures included: growing spine device (3), hemivertebrae excision (4), posterior fusion (7), cervical fusion (2), and vertebral column resection (1). Congenital deformity was the most common diagnosis. Primary outcome measures were need for intraoperative screw revision or complication associated with screw placement. Mean number of screws used per procedure was 8.1 (range, 2-17). Screws were placed from C1 to L5. Of the 137 screws, 3 required revision to shorter screws for an overall accuracy rate of 97.8%. In 1 case, a right T3 screw was revised due to anterior penetration. In another case, left-sided T1 and T2 pedicle screws were shortened 5 mm because they had penetrated the anterior aspect of their respective vertebral bodies. There were no screw-related complications. In this series, image-guided navigation resulted in accurate placement of screws in patients aged 10 years or younger with no associated intraoperative complications. The navigated accuracy rate (97.8%) is significantly higher (P=0.01) than the reported 90.9% pedicle screw accuracy rate without navigation in the same age group by Baghdadi and colleagues. Intraoperative CT and image guidance were useful in our practice for placement of screws in skeletally immature patients.

To evaluate the accuracy and safety of C1–C2 pedicle screw placement using O-arm navigation, individualized 3D-printed guides, and C-arm fluoroscopy. Clinical data of 47 patients who underwent C1–C2 spinal fixation surgery at our institution between January 2015 and December 2020 were retrospectively analyzed. The cohort included 28 males and 19 females, aged 15–59 years (mean age: 46.23 ± 9.97 years). Patients were categorized into three groups based on the screw placement technique: navigation group (11 cases; O-arm S8 navigation system), guide group (15 cases; individualized 3D-printed guides), and fluoroscopy group (21 cases; C-arm fluoroscopy guided by anatomical landmarks). Outcome measures included surgical time, screw placement time, intraoperative blood loss, single-pass screw placement success rate, screw placement accuracy, and complication rate. Surgical Metrics: The Navigation group demonstrated a mean surgical time of 120.72 ± 11.14 min, screw placement time of 20.00 ± 1.09 min, and blood loss of 225.81 ± 25.58 ml. The Guide group reported significantly shorter surgical time (97.46 ± 9.03 min, P < 0.001), shorter screw placement time (15.80 ± 1.93 min, P < 0.001), and reduced blood loss (162.66 ± 18.52 ml, P < 0.001). The Fluoroscopy group showed longer surgical time (121.04 ± 12.81 min) and higher blood loss (239.04 ± 24.54 ml) compared to the other groups. Screw Placement Success and Accuracy: A total of 188 screws were placed (44 in the Navigation group, 60; guide group, and 84; Fluoroscopy group). The single-pass success rates were 100% (44/44) in the navigation group, 93.3% (56/60) in the guide group, and 80.9% (68/84) in the fluoroscopy group (P = 0.002). Screw placement accuracy was 100% (44/44) in the navigation group, 98.3% (59/60) in the guide group, and 85.7% (72/84) in the fluoroscopy group (P = 0.039). Notably, three screws in the fluoroscopy group breached the vertebral artery foramen; however, no cerebrovascular ischemic events were observed. Complications: Two patients in the fluoroscopy group developed postoperative occipitocervical pain owing to intraoperative irritation of the C2 nerve root. Symptoms resolved after corticosteroid and diuretic therapy. No occipitocervical pain or other complications were reported in the Navigation or Guide group. All the incisions healed without infection or delayed recovery. O-arm S8 navigation system and individualized guide plate assisted atlantoaxial screw placement can achieve high and stable accuracy, which is better than the traditional freehand screw placement technique under fluoroscopy; O-arm navigation technology has an advantage in the one-time success rate of atlantoaxial screw placement, which is higher than that of the guide plate group and the fluoroscopy group; Individualized guide plate combined with lateral fluoroscopy can accurately place atlantoaxial screws, save operation time and reduce bleeding.

Spine surgery still remains a challenge for every spine surgeon, aware of the potential serious outcomes of misplaced instrumentation. Though many studies have highlighted that using intraoperative cone beam CT imaging and navigation systems provides higher accuracy than conventional freehand methods for placement of pedicle screws in spine surgery, few studies are concerned about how to reduce radiation exposure for patients with the use of such technology. One of the main focuses of this study is based on the ALARA principle (as low as reasonably achievable). A prospective randomized trial was conducted in the hybrid operating room between December 2015 and December 2016, including 50 patients operated on for posterior instrumented thoracic and/or lumbar spinal fusion. Patients were randomized to intraoperative 3D acquisition high-dose (standard dose) or low-dose protocol, and a total of 216 pedicle screws were analyzed in terms of screw position. Two different methods were used to measure ionizing radiation: the total skin dose (derived from the dose-area product) and the radiation dose evaluated by thermoluminescent dosimeters on the surgical field. According to Gertzbein and Heary classifications, low-dose protocol provided a significant higher accuracy of pedicle screw placement than the high-dose protocol (96.1 versus 92%, respectively). Seven screws (3.2%), all implanted with the high-dose protocol, needed to be revised intraoperatively. The use of low-dose acquisition protocols reduced patient exposure by a factor of five. This study emphasizes the paramount importance of using low-dose protocols for intraoperative cone beam CT imaging coupled with the navigation system, as it at least does not affect the accuracy of pedicle screw placement and irradiates drastically less.

What's New in Spine Surgery.

Wednesday, September 26, 2018 7:35 AM–9:00 AM ePosters

A retrospective analysis of patients undergoing spinal deformity correction surgery by the assistance of intraoperative computed tomography (iCT) with or without navigation system. To share our preliminary experience and analysis of the iCT navigation system applied to spinal deformity surgery. The iCT navigation system has been shown to improve accuracy and safety in posterior instrumentation. It not only decreased the operation time but also prevented excessive radiation exposure to the medical staff. To date, there are only few reports about the application of the iCT navigation system in spinal deformity surgery. From April 2009 to September 2010, 59 patients who had a diagnosis of scoliosis, kyphosis, or scoliokyphosis and underwent iCT-assisted surgical correction were included. Without randomization, 28 patients were operated with the iCT-navigation system, and the other 31 patients were operated with standard procedure under iCT assistance. The detailed procedures, preoperative and intraoperative images were illustrated. The accuracy of screw placement, time for screw insertion, postoperative correction rate, and iCT scanning data were analyzed. There were significant differences between 2 groups in (1) the preoperative Cobb angle (76.2° and 62.6° in the navigation and non-navigation groups), (2) the accuracy and the revision rate of thoracic pedicle screws and total pedicle screws, and (3) the average screw insertion time. The breach rate and the revision rate of thoracic pedicle screws and total pedicle screws were significantly lower and the average screw insertion time was significantly lesser in the navigation group than in the non-navigation group. There were no statistically significant difference in (1) the breach rate and the revision rate of lumbar pedicle screws, (2) the mean iCT scanning time and time-out, (3) the mean number of fusion segments, (4) the mean number of iCT scans, and (5) the postoperative correction rate. Complications were encountered in 2 patients in the non-navigation group but none in the navigation group. There was no reoperation due to implant malposition in both groups. The iCT navigation system provides desirable accuracy of posterior spinal instrumentation for patients during surgical correction of spinal deformity without radiation exposure to the medical staff, especially in thoracic spine instrumentation. Meanwhile, the iCT in itself is an effective means of assessing complex instrumentation of the spinal deformity.

Introduction: Although many studies have evaluated the accuracy of pedicle screw (PS) placement using various techniques, few have conducted large-scale comparisons of open and percutaneous approaches using CT navigation and fluoroscopy within a single institution. This study aimed to evaluate the accuracy of lumbar PS placement based on four different insertion techniques and to identify factors influencing screw placement accuracy.Methods: A total of 237 cases (1,081 screws) of PS placement at the L1-S1 level were retrospectively analyzed. Patients were divided into four groups: open CT navigation, percutaneous PS (PPS) CT navigation, PPS fluoroscopy, and open freehand. Screw accuracy was assessed using the Gertzbein-Robbins classification based on postoperative CT or intraoperative O-arm images. The proportions of grade A (no breach) and grade A or B (≤2 mm breach) screws were compared among the groups. Statistical analyses included Fisher’s exact test with Bonferroni correction.Results: The proportion of grade A screws was highest in the open CT navigation group (96.4%), followed by PPS fluoroscopy (89.3%), open freehand (88.0%), and PPS CT navigation (81.0%) (p < 0.05). Grade A or B screws exceeded 95% in all groups with no significant differences. Lateral breaches were the most frequent, particularly in the PPS CT navigation (93.3%) and PPS fluoroscopy (82.0%) groups. No grade D or E medial or caudal breaches or neurological complications were observed. Screw repositioning was required in two cases (three screws) due to lateral breaches >4 mm with screw tips located outside the vertebral body.Conclusions: All four insertion techniques achieved high accuracy, with more than 95% of screws classified as acceptable placements and no neurological complications observed. These findings suggest that lumbar PS placement can be performed safely and reliably across different techniques when applied appropriately.

Background and purposeAlthough navigation is increasingly used in spinal surgery, the advantage of different navigation technologies is still a matter of debate. Conventional image-guided navigation is currently the gold standard. However, modern, Augmented reality-based navigation methods are increasingly gaining ground. Surgical navigation in deformity surgery allows placement of pedicle screws in small and deformed pedicles and may result in both a higher accuracy and density of pedicle screw placement. The aim of this trial is to compare AR and conventional surgical navigation to free-hand technique.Patients and methodsThis is a single center, open label, parallel assignment, three arm, randomized, controlled trial, comparing: Augmented reality surgical navigation (ARSN), Infrared surgical navigation (IRSN) and Free-hand (FH) technique. Individuals scheduled for spinal deformity surgery are eligible for inclusion. The inclusion criteria are written informed consent, age ≥ 12 years and spinal deformity. Subjects will be randomized intraoperatively and strictly sequentially.OutcomesThe primary endpoint is accurately placed pedicle screws based on intraoperative verification cone beam computed tomography (CBCT) scan. All radiological image analyses, on both intra- and postoperative imaging will be performed postoperatively by blinded reviewers.Several secondary outcome measures including revision rate, radiation exposure, implant density and final accuracy will be analyzed. Patient reported outcomes will also be assessed. Finally, a cost–benefit analysis will be performed.Start of trial and estimated durationThe SPINAV trial started recruiting patients in January 2022 and will continue for approximately 2.5 years.Trial registrationThe trial is registered at clinicaltrials.gov (NCT05107310) on 2021–11-03.

Introduction Intraoperative CT and navigation systems may provide an opportunity to improve precision and accuracy of pedicle screw placement, and in so doing, improve patient outcomes. Adult spinal deformity provides unique anatomical challenges potentially amenable to spinal navigation. Our study aimed to examine the efficacy and safety of intraoperative cone beam CT navigation for pedicle screw placement in complex spinal deformity cases. Material and Methods We identified all patients treated at our institution with spinal fusion for the primary diagnosis of major adult deformity between January 2008 and December 2012 in whom O-arm and StealthStation navigation was used (NAV). A historic control cohort (non-NAV) was matched based on age, number of levels, curve type and size, and previous fusion. The number and timing (intraoperative, early symptomatic postoperative, late symptomatic postoperative, and incidental) of screw malposition and the need for revision screw placement were recorded. All patients had a minimum follow-up of 1 year. Any screw with pedicle breach greater than 0 mm was recorded as misplaced. The direction and anatomical level of misplaced screws were also determined. Quantitative statistical analysis compared screw placement between NAV and non-NAV cases. Results A total of 56 patients met the inclusion criteria in both cohorts (112 patients). The mean number of screws placed in each group was not significantly different (17.29 in NAV and 17.71 in non-NAV, p = 0.75). Thirty-eight (34%) patients in the non-NAV group had misplaced screws compared with 21 (19%) in the NAV group ( p = 0.002). The detection of incidental screw malposition was significantly higher in the non-NAV cases (44.6 vs. 23.2%, p &lt; 0.05) and the need for intraoperative screw revision favored navigation ( p &lt; 0.03). Six cervical screws, 16 cervicothoracic, 90 thoracic, and 112 lumbar screws were placed. Early postoperative screw revision rates approached significance ( p &lt; 0.06) favoring navigation. The number of adverse events and length of stay (mean 17 vs. 20.4 days in NAV and non-NAV groups, respectively) were not significantly different. The mean number of postoperative CT scans was significantly fewer in the NAV group (9 vs. 22 in non-NAV group, p = 0.004), while mean OR time was statistically different between groups (492 minutes in the NAV group vs. 408 minutes in the non-NAV, p = 0.002). Conclusion Our results demonstrate that intraoperative CT-guided navigation provides an equally safe and more accurate and precise tool for pedicle screw placement than traditional techniques in adult spinal deformity surgery. There were more intraoperative screws adjusted and fewer postoperative screws revised with NAV. Far fewer patients required postoperative CT examination with the use of NAV.

Over the past 2 years, the COVID-19 pandemic has impacted the entire health-care profession, and spinal surgery had to adjust along with it. Although it may take years to truly assess the overall effect, early trends have clearly pointed toward a patient demand for telemedicine. Additionally, as COVID strained our hospitals and diverted critical resources away from elective surgical procedures, non-time-sensitive cases have been increasingly pushed out to outpatient surgical centers. Decreased inpatient elective surgical capability has also forced more patients to pursue extended nonoperative treatment modalities. Although it remains too early to determine the long-term impact of these shifts, we expect future studies to examine these issues extensively. This annual update on spine surgery includes an examination of peer-reviewed literature for all spinal conditions, in addition to abstracts presented at annual society meetings, over the past year. We chose these articles due to their potential to impact and advance our profession, with a preference toward the highest levels of evidence. Spondylotic Cervical Myelopathy Several interesting studies published recently added to our understanding of optimal surgical treatment for spondylotic cervical myelopathy. In the Cervical Spondylotic Myelopathy Surgical (CSM-S) randomized clinical trial, Ghogawala et al. compared the impact of anterior surgery with that of posterior surgery on patient outcomes1. In a select population in which clinical equipoise existed (exclusion of patients with kyphosis of >5°, ossification of the posterior longitudinal ligament, or segmental kyphotic deformity), 1-year and 2-year Short Form-36 (SF-36) Physical Component Summary (PCS) scores were not different between the 2 groups. The authors did identify a higher complication rate in the anterior surgery group, with dysphagia predominating. The major complication rates did not differ. Interestingly, in the nonrandomized analysis comparing laminoplasty, posterior cervical fusion, and anterior cervical fusion, the patients who underwent laminoplasty fared significantly better in physical function, complication rate, and resource utilization. Posterior cervical fusion is more commonly performed in the United States, and a recent study demonstrated that laminoplasty is likely underutilized despite growing evidence for improved performance metrics2. Current literature has mixed results with regard to determination of the optimal lower instrumented vertebra (LIV) in long posterior cervical fusions. In addressing the question of crossing the cervicothoracic junction, Truumees et al.3 evaluated patient-reported outcomes, radiographic outcomes, and revision rates in fusions stopping at C6/7 or T1/2 in a retrospective analysis of 264 patients with at least a 2-year follow-up. Patient-reported outcome measures improved equally in both groups. Radiographic outcomes were similar between groups, with both groups demonstrating similar improvement in cervical lordosis. The study did not detect a difference in revision rates, but was not powered to do so. Patients who underwent fusions into the thoracic spine did have more blood loss and longer operative time. Similarly, in a retrospective cohort study with a 4-year follow-up, Guppy et al. did not identify a difference in reoperation rates for adjacent segment disease4 or pseudarthrosis5 when cervical fusions were stopped at C7 or T1/T2. In the absence of extenuating factors, stopping at C7 may be a reasonable option given the lower morbidity and complication rate, although further work is needed in this area. Cervical Radiculopathy Numerous studies have been published comparing cervical disc arthroplasty with anterior cervical discectomy and fusion (ACDF). However, many of these studies may have been biased by industry sponsorship and a lack of blinded outcome assessment. The Norwegian Cervical Arthroplasty Trial (NORCAT) was designed as a blinded and randomized clinical trial of 136 patients comparing patient-reported outcomes after ACDF or cervical disc arthroplasty for single-level disease6. The patients and surgeons were blinded, with the treatment arm revealed to the surgeon only after neurologic decompression was completed. Both groups demonstrated a significant improvement in the Neck Disability Index (NDI) at 5 years, without a difference observed between groups. Secondary outcomes, including neck pain, arm pain, and adjacent segment disease, were not different between groups. The reoperation rate was not significantly different between groups, and nearly all reoperations were at the index level. Only 1 patient underwent reoperation for adjacent segment disease at 5 years. This study demonstrates that clinical outcomes are likely independent of implant choice; however, the effect on adjacent segment disease needs to be addressed with longer-term follow-up. The 10-year Investigational Device Exemption (IDE) trial data for the Bryan and Mobi-C cervical disc arthroplasty devices are now available. In a study comparing adverse events between the Bryan cervical disc arthroplasty and ACDF, Loidolt et al. demonstrated a similar rate of adverse events over a 10-year period7. The rate of revision surgery at the index level was not significantly different between the 2 groups. The rate of adjacent level surgery in the ACDF group trended higher (15.8% compared with 9.7%) but did not reach significance at 10 years. Additionally, the 10-year outcomes from the Mobi-C IDE trial were published8. This study was limited by lack of an ACDF control group and had an approximately 73% follow-up rate from the original cohort. At 10 years, the authors identified a rate of revision surgery of 5.1% at the index level and 4.3% at the adjacent level. No serious adverse events were reported between 7 and 10 years. One of the most common symptoms after anterior cervical surgery is dysphagia. In a meta-analysis of 7 randomized controlled trials, Garcia et al. evaluated the dysphagia rate after ACDF with prophylactic administration of local or intravenous corticosteroid9. The study provides moderate-quality evidence that the administration of corticosteroids reduces the dysphagia rate and severity after ACDF. A subgroup of studies on the pseudarthrosis rate did not identify a difference. No infections were reported in this meta-analysis. In a recent, well-designed, randomized, and double-blinded controlled trial, Kim et al.10 corroborated these results: after undergoing multilevel ACDF, patients received retropharyngeal corticosteroid or placebo. Dysphagia was assessed with validated outcomes. The corticosteroid group had significantly better scores at all time points up to 1 month. These results suggest that corticosteroid administration likely reduces dysphagia rates, although the effect on pseudarthrosis remains to be fully elucidated. Lumbar Disc Herniation and Lumbar Degenerative Conditions Lumbar disc herniation remains a common clinical problem11. Several recent studies have examined options for the management of lumbar disc herniation. In a randomized controlled trial, Wilby et al. compared microdiscectomy with transforaminal epidural corticosteroid injection in patients with persistent radicular pain for <1 year secondary to disc herniation12. The authors found that there were no significant differences in pain scores between the epidural injection group and the surgery group, although 18% of the injection group underwent a surgical procedure prior to the completion of the study. The authors also posited that a surgical procedure is less cost-effective than an epidural injection, although this work is ongoing. In a systematic review and meta-analysis, Wei et al. compared open microdiscectomy, microendoscopic discectomy, percutaneous endoscopic discectomy, tubular discectomy, and percutaneous discectomy13. The authors found no significant differences between most approaches, except that percutaneous endoscopic discectomy had the best safety and efficacy, although this review was limited by the heterogeneity of the included studies. Ran et al. compared computed tomography (CT)-navigated percutaneous endoscopic discectomy with open microdiscectomy in 68 patients and found that the percutaneous discectomy group reported less postoperative back pain and the percutaneous approach generated lower serum markers of muscle trauma14. In a systematic review and meta-analysis, Gadjradj et al. found that moderate-quality evidence supports percutaneous transforaminal endoscopic discectomy as an equivalent treatment to open microdiscectomy, but there is a paucity of high-quality evidence comparing the 2 approaches15. Additionally, the topic of annular repair or other implants to reduce reherniation rates has been reexamined in the last 2 years. In a systematic review, Rickers et al. found a trend toward improved outcomes with annular repair. In contradistinction to the prior study, the authors also found that percutaneous discectomy performed the worst of all current surgical approaches, although, overall, there were no significant differences between treatments16. Additionally, the risk of bias was high in 15 of the 32 included studies. The debate with regard to the optimal management protocol for lumbar degenerative spondylolisthesis has continued lately. Heemskerk et al.17 compared open transforaminal lumbar interbody fusion (TLIF) and minimally invasive surgery (MIS)-TLIF for patient-reported outcomes, and Droeghaag et al.18 compared open TLIF and MIS-TLIF for cost-effectiveness. Heemskerk et al. found that MIS-TLIF and open TLIF had equivalent outcomes at the 2-year follow-up; Droeghaag et al. found that MIS-TLIF is more cost-effective than open TLIF. These results suggest that MIS-TLIF may be an important tool in the long-term management of lumbar degenerative spondylolisthesis. However, in a meta-analysis of 7 studies, Zhang et al. found that oblique lateral interbody fusion with supplementary posterior fixation yielded better improvements in symptoms compared with MIS-TLIF and was associated with a shorter operative time19. Furthermore, the type of posterior fixation for lumbar fusion remains controversial. In a systematic review and meta-analysis, Chang et al. compared traditional pedicle screws with cortical-based trajectory screws for the treatment of lumbar degenerative spondylolisthesis in patients who underwent interbody fusion20. The authors found that cortical screws were associated with decreased operative time and less blood loss during the surgical procedure, but the overall fusion rates were similar at 1 year. Additionally, Zhu et al. performed a systematic review and meta-analysis comparing MIS-TLIF and endoscopic TLIF, which demonstrated the noninferiority of the endoscopic approach compared with traditional minimally invasive techniques21. The applications of navigation and robotics continue to rapidly expand in the field of spinal surgery. Fu et al.22 and Zhou et al.23 both performed meta-analyses comparing the freehand placement of pedicle screws with robotic-assisted placement. Both studies found significant improvements in pedicle screw accuracy, including reduced violation of the cephalad facet joint and intraoperative radiation dose, with robotic assistance, although revision rates for screw malpositioning were similar in the latter article. Klingler et al. performed a randomized trial of fluoroscopically assisted MIS-TLIF and navigated TLIF and found that the type of navigation used in the study did not significantly reduce radiation exposure to the surgeon, while simultaneously increasing radiation exposure to the patient24. Therefore, the role of navigation and robotics is still being developed. There has also been increasing interest in single-position prone lateral lumbar interbody fusion as an option for patients requiring surgical stabilization for spondylolisthesis. Walker et al. performed a retrospective review of 30 patients with spondylolisthesis undergoing either prone or lateral decubitus lateral interbody fusion with posterior instrumentation25. The authors found that the prone position yielded significantly improved segmental lordosis compared with the traditional position. Additionally, Guiroy et al. performed a systematic review comparing these approaches and found that single-position lateral decubitus trended toward shorter operative time and hospital stay, although only 4 studies were included26. Interestingly, in a separate systematic review and meta-analysis, Mills et al. examined lateral decubitus compared with the prone position without repositioning and found that the single-position lateral decubitus reduced operative time and radiation exposure compared with the prone position, and the improvement in segmental lordosis was higher in the prone group27. However, pedicle screws placed using the lateral decubitus position had a higher rate of complications. Perioperative Pain Management There has been increasing interest in the utilization of local or regional anesthesia for pain control in patients undergoing lumbar spinal surgery. Erector spinae plane blockade continues to gain traction in this regard. In randomized controlled trials, Jin et al.28 examined the efficacy of an erector spinae plane block in patients undergoing lumbar laminoplasty, and Zhu et al.29 and Goel et al.30 examined the efficacy of an erector spinae plane block in patients undergoing single-level lumbar fusion. The authors found that erector spinae plane blockade resulted in significantly reduced postoperative pain scores, reduced opioid consumption, and higher patient satisfaction, suggesting that erector spinae plane blockade should become more routinely utilized in the perioperative period. Liposomal bupivacaine injection is an additional multimodal pain management technique to reduce postoperative pain and opioid consumption. Nguyen et al. performed a systematic review of retrospective cohort studies and randomized controlled trials investigating this technique and found that lower-quality evidence supports its use and moderate-quality studies were equivocal31. The authors maintained that higher-quality studies are needed before the efficacy of this technique can be fully appreciated. Multimodal anesthesia and various enhanced recovery after surgery (ERAS) postoperative pain management protocols have been developed to expedite patient recovery and improve satisfaction after spinal surgery. Recently, there have been several high-quality studies adding to the data on this topic. Soffin et al. published a trial of 56 patients randomized to either the ERAS protocol after lumbar fusion or traditional postoperative pain management, finding decreased opioid consumption and improved patient-reported pain scores in the immediate postoperative period with the ERAS protocol32. However, significant clinical impact was not proven with the ERAS protocol, which was possibly related to the small sample size. In a randomized controlled trial, Kraiwattanapong et al. similarly evaluated multimodal drug infiltration in the postoperative wound bed, demonstrating that this technique reduced postoperative pain scores and opioid consumption33. Sharaf et al. performed a randomized controlled trial comparing postoperative physical therapy with and without neural mobilization in patients who underwent lumbar decompression for stenosis; the authors found that the addition of neural mobilization improved outcomes across all patient-reported outcome measures34. Lastly, Ma et al. performed a prospective randomized trial evaluating the utility of postoperative spinal orthoses after MIS-TLIF35. The authors found that the use of a postoperative orthosis had no significant effect on the Oswestry Disability Index (ODI) or visual analog scale pain score at 6 or 12 months after MIS-TLIF. Additionally, the orthosis had no effect on the fusion rate at the final follow-up. Adult Spinal Deformity Surgical decision-making for patients with adult spinal deformity is complex. In several recent studies, authors have examined the risk-and-benefit calculation that aids our surgical indications, patient optimization, and preoperative counseling. The Prospective Evaluation of Elderly Deformity Surgery (PEEDS)36 study illustrates the potential benefit of spinal deformity surgery: this prospective, multicontinental study evaluated disability (ODI) in patients ≥60 years of age who underwent spinal deformity surgery. The authors demonstrated that, after an initial recovery period, 70% of patients experienced at least 10% improvement from their baseline disability, which was sustained at 2 years. Meanwhile, approximately 25% of patients reported no change from baseline and approximately 5% of patients reported worsening of the disability. Importantly, although there was an overall significant improvement in disability, the mean ODI of 27% at 2 years was still worse than normative values, and was consistent with moderate disability. This article also stratified the shift in ODI based on preoperative ODI deciles, which is a useful counseling tool for shared decision-making. Similar findings were identified in the 5-year outcomes reported by the Scoli-RISK-1 Study Group37. This study was limited by a 5-year follow-up rate of 28%, but identified a significant improvement in patient-reported outcomes, with 62% of patients having a clinically meaningful improvement in the ODI score. Numerous studies have shown the complication profile of deformity surgery. The 5-year results from the Scoli-RISK-1 Study Group demonstrated worse lower-extremity motor scores in 9.3% of patients who were available for follow-up at 5 years38. This rate was improved from 14% at the time of hospital discharge and was unchanged from 2 years postoperatively. In a recent study, Lakomkin et al.39 helped to contextualize the surgical invasiveness of deformity surgery by comparing it with other major operations. Using a variation of the validated Postoperative Morbidity Survey score, the authors added length of hospital stay and operative time to develop the novel Surgical Invasiveness and Morbidity Score (SIMS). Using the National Surgical Quality Improvement Program (NSQIP) database and controlling for comorbidities, the authors compared SIMS across major surgical procedures. Adult spinal deformity surgery fared better than coronary artery bypass grafting, abdominal aortic aneurysm repair, and cystectomy, performed similarly to mitral valve replacement, and was, overall, worse than prostatectomy, total shoulder arthroplasty, and hip fracture fixation. This study provides an intuitive counseling tool for patients considering adult spinal deformity surgery. Several studies have shown the importance of patient frailty as a predictor of outcomes and complications. Passias et al.40 demonstrated that frailty was independent of chronological age in predicting positive outcomes in adult spinal deformity surgery. Patients ≥70 years of age who were not frail fared better than elderly patients who were frail or severely frail. Gum et al.41 demonstrated that the cost of quality-adjusted life-year (QALY) was impacted more by patient frailty than by surgical invasiveness. Frail and severely frail patients had significantly and incrementally higher costs per QALY than non-frail patients. Surgical invasiveness did not have a substantial impact on cost per QALY. The authors recommended focusing on patient optimization with respect to modifiable risk factors to improve cost optimization. These studies help to understand the risk and benefit of adult spinal deformity surgery and provide an increased awareness of patient factors that may impact outcomes. Nonoperative Treatments Spine surgery continues to evolve with the rest of the surgical profession, and, as many have proven, high-quality randomized controlled trials are difficult to perform with surgical procedures. In contrast, our interventional pain colleagues may be better positioned to conduct studies within this gold standard of evidence-based medicine. Their ability to do so, coupled with an increase in the nonoperative treatment environment, has created an exponential growth across the United States at a time when our patients were hesitant to seek hospital-based care. A thorough discussion of all available pain management procedures is beyond the scope of this update, but we believe that it is particularly important that all orthopaedic surgeons understand the basics behind these procedures and the early evidence to support their use. We do advise the reader that each of the studies in this section was industry-funded. The minimally invasive lumbar decompression (mild) procedure is approved by the U.S. Food and Drug Administration (FDA) for the treatment of neurogenic claudication and gained approval for reimbursement by the U.S. Centers for Medicare & Medicaid Services (CMS) in 2017. The procedure uses a small portal to remove part of the lamina and ligamentum flavum using radiographic assistance. Most recently, in 2021, Deer et al. published the 6-month results of a randomized controlled trial comparing the mild procedure with conventional medical management and found the mild procedure to have superior results, albeit in very early results42. Multiple interspinous devices are currently available on the market, and we have seen an increased use among our pain management colleagues. These devices have an established role in the management of neurogenic claudication, but their specific indications continue to evolve. Schenck et al. recently reported the results of their 5-year randomized controlled trial of interspinous devices compared with decompressive surgery and found similar results, but with a higher risk of reoperation within the first 2 years following use of interspinous devices43. Intraosseous basivertebral nerve ablation procedure was approved by the FDA in 2016 for the treatment of chronic low back pain in patients with disc degeneration and Modic end plate changes. This procedure has recently demonstrated positive results. Fischgrund et al. performed a double-blinded randomized trial, finding that the ablation of the basivertebral nerve yielded continued improvement in pain and function at a mean of 6.4 years postoperatively in this challenging patient population44. Telemedicine in Spine Surgery With the COVID-19 nearly the entire spine a in surgical procedures and an increase in The of and there has been exponential growth within the most of the literature on the and with articles evaluating the long-term outcomes of so. Several authors validated the performance of the with an on the neurologic Similar to the rest of the the spine to back with Over the past 2 years, we have different and expect to continued growth of this important advance forced by the Although this has been a of the it not the among colleagues in At the time of this all future society are currently to be at the Spine in in the Cervical Spine in in the in in the Lumbar Spine in in the Spine in and the of in in The of a of recently published studies related to the that received a higher of In addition to articles in this update, 6 other articles to spine surgery are to this review after the standard with a each article to help further in an evidence-based in this area. with or without fusion in degenerative lumbar spondylolisthesis. In a noninferiority study, et al. evaluated all patients with lumbar degenerative spondylolisthesis with a of who were randomized to either decompression or decompression and fusion. The of and evidence of a were not into their The outcome was an improvement of the ODI score by At 2 years, an equivalent of patients had a clinically important improvement of the ODI in the group and in the decompression and fusion at 2 years, reoperation rates trended higher in the group at than in the decompression and fusion group at but this difference was not This study was limited by the heterogeneity of the included as the and of degenerative spondylolisthesis were not included in the reoperation rates be useful in understanding the of decompression in the of degenerative spondylolisthesis. this study useful to the debate fusion for degenerative but of the of patients who benefit most from decompression and fusion compared with decompression Current of adjacent segment following lumbar fusion a systematic review and meta-analysis of recent Spine The risk of adjacent segment degeneration at adjacent levels to lumbar fusion remains a clinical surgery has been developed to this et al. performed a systematic review comparing these and the reported rate of adjacent segment The authors found no significant differences in adjacent segment disease or reoperation between groups, although the analysis demonstrated lower of adjacent segment degeneration in the The of included studies was there still is no on surgery decreased adjacent segment a systematic review and meta-analysis comparing Spine In a systematic review and meta-analysis, et al. compared stabilization with fixation for lumbar had improved length of stay, operative and blood loss but worse loss of deformity at final Patient-reported outcomes were not significantly different between groups. The literature remains on which surgical approach is of arthroplasty fusion for patients with cervical a randomized clinical et al. performed a randomized clinical trial comparing single-level ACDF with cervical disc Patients were blinded to and surgeons were blinded to treatment neurologic decompression was completed. The outcome was the and the secondary outcomes were arm and neck pain scores, of reoperation rate, and adjacent segment There were 136 patients with follow-up at 5 years. scores significantly improved in both groups, without a difference observed between groups. No differences were in reoperation rate or adjacent segment This study demonstrated that neck disability scores were not significantly different between groups within 5 years. for adjacent segment disease and reoperation longer-term follow-up. of to surgical after spine surgery: a systematic review and meta-analysis. Pain et al. performed a systematic review and meta-analysis of studies only 6 were randomized controlled and found that the addition of in the wound after spinal as as and a of the 2 yielded significant in surgical corroborated by this systematic review, reduce after spine surgery. in a systematic review and meta-analysis of randomized controlled Spine et al. performed a systematic review and meta-analysis of the available literature comparing the use of orthoses with no in the management of The authors found that, overall, there were no significant differences between the group orthoses and the group with no with regard to pain scores or radiographic and recommended that treatment of not These findings studies on the topic.

Introduction The improved screw accuracy of intraoperative 3D imaging with navigation has been primarily reported in cadaveric studies and spinal deformity surgeries. Revision surgery poses unique technical challenges for pedicle screw instrumentation because of an established fusion mass, lack of reliable anatomical landmarks, and limited fixation options. The aim of this study was to examine our early experience of pedicle screw malposition rates in revision surgeries comparing O-arm and StealthStation navigated cases to the traditional freehand technique and evaluate the impact on patient outcome. Materials and Methods This ambispective study compared two matched cohorts of patients undergoing revision thoracolumbar surgery. The study group comprised 56 consecutive patients who underwent O-arm and StealthStation navigation-assisted pedicle screw instrumentation (NAV) between January 1, 2008 and December 31, 2012. The control group comprised 34 historical matched cases with surgery between January 1, 2006 and December 31, 2008, using traditional (freehand or with fluoroscopy), nonnavigated techniques (non-NAV). Cases were matched on age, gender, surgical location, number of surgical levels, and primary diagnosis. We examined the differences in screw placement and accuracy, patient outcomes, and surgery-related adverse events. Results There was a significant difference in the number of misplaced screws between the NAV and non-NAV groups (31 vs. 54, p &lt; 0.001). The average number of misplaced screws per case was 0.57 (SD = 0.92) with navigation and 1.86 (SD = 2.49) without ( p = 0.01). No difference existed in the number of screws revised intraoperatively (10 vs. 7, p = 0.54). One patient in the NAV group and two patients in the non-NAV group required early postoperative screw revision during the same admission ( p = 0.33). No screws in the NAV group required revision during subsequent admissions. No difference was observed in grade of screw malposition ( p = 0.11) or anatomical location of malposition ( p = 0.26). Anatomically, a majority of misplaced screws were located below T6 in both groups. The use of navigation resulted in a significant difference in intraoperative massive blood loss (&gt; 2L in 3 hours), 3.3% of the NAV cases compared with 7.8% of the non-NAV cases. There was no significant difference in the duration of surgery ( p = 0.11), incidence of intraoperative dural tear ( p = 1.00), wound infection ( p = 1.00), or length of stay ( p = 0.78). Conclusion This early analysis of our experience in revision surgery demonstrates an increased accuracy of pedicle screw placement utilizing O-arm imaging and StealthStation navigation systems, without an increase in OR time. Small case numbers likely explain the comparable early screw revision rates, as our experience with a larger number of degenerative cases demonstrates a statistically significant reduction in reoperation for symptomatic screw misplacement. The use of intraoperative 3D imaging and navigation in revision spine surgeries results in lower mean blood loss, and fewer cases of massive intraoperative blood loss may occur because navigation avoids the extent of dissection normally required and facilitates safe pedicle screw instrumentation while minimizing surgical exposure. Data collection and analysis is ongoing to examine diagnosis-specific incidence of screw malposition and patient outcome.

Objective: To comparing the accuracy of pedicle screw placement in posterior surgery for adult degenerative scoliosis (ADS) between robotic-assisted and traditional freehand techniques. Methods: This retrospective study included 92 patients with ADS who underwent posterior spinal surgery at the First Affiliated Hospital of Nanjing Medical University (Jiangsu Province Hospital) between March 2019 and December 2023. There were 19 males and 73 females with a mean age of (63.6±9.8) years. The patients were divided into two groups based on the technique used for pedicle screw placement: robot-assisted group (34 cases) and manual group (58 cases). Operative duration, intraoperative blood loss, facet joint violation, postoperative complications, magnitude of curve correction, visual analogue scale (VAS) and Oswestry Disability Index (ODI) scores preoperatively, 1 week postoperatively, and 1 month postoperatively were compared and analyzed between the two groups. The Gertzbein-Robbins classification criteria was used to assess the accuracy of screw placement. Results: Differences in baseline data, operative duration, intraoperative blood loss, magnitude of curve correction, and VAS and ODI scores preoperatively, 1 week postoperatively, and 1 month postoperatively between the two groups exhibited no statistically significant differences (all P>0.05). The accuracy of pedicle screw placement in the robot-assisted group was significantly higher than that in the manual group [90.9% (416/458) vs 80.1% (697/870), P<0.001]. In terms of surgical segments, in T1-T12 and L1-S1 segments, the accuracy of pedicle screw placement in the robot group were both significantly higher than those in the control group [91.5% (130/142) vs 77.8% (186/239), P=0.001; 90.3% (271/300) vs 80.8% (502/621), P<0.001]. However, no significant differences was observed in the accuracy of S2-alar-iliac (S2AI) screw placement between the two groups [90.0%(9/10) vs 93.8%(15/16), P=0.727]. Moreover, no significant differences was found in the deviation direction of the cortical screw penetration between both groups (P=0.133). Significant differences were observed in the accuracy of screw placement between the Nash Moe 2 and 3 vertebral bodies in the robot group compared with those in the control group [88.9% (88/99) vs 71.0% (115/162), P=0.001; 89.2% (83/93) vs 60.2% (68/113), P<0.001]. Additionally, the incidence and grade of facet joint violation in the manual group were both significantly higher than those in the robot-assisted group (both P<0.001). No statistically significant differences was identified in postoperative complications between the two groups (P=0.841). Conclusion: It suggests that robot-assisted pedicle screw placement in posterior surgery for patients with ADS can significantly improve the accuracy of screw placement and reduce the incidence of facet joint violation.

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.