Which components of the global alignment proportionality score have the greatest impact on outcomes in adult spinal deformity corrective surgery?

PURPOSE: To investigate the impact of the Global Alignment and Proportion (GAP) score components on patient outcomes in Adult Spine Deformity (ASD) surgery. METHODS: Patients included underwent assessment via the GAP score and its individual components: pelvic version (GAP PV), lumbar lordosis (GAP LL), lumbar distribution index (GAP LDI) and spinopelvic component (GAP SP). Multivariable analyses assessed the association between alignment in these components and clinical outcomes in ASD patients. RESULTS: 762 ASD patients met inclusion criteria. Alignment in GAP SP independently predicted meeting MCID for SR-22S and ODI and was associated with a lower likelihood of developing mechanical complications. Patients aligned in GAP SP were less likely to develop proximal junctional kyphosis (OR 0.42, 0.26-0.73, p = 0.01) and PJF (OR 0.3, 0.13-0.74, p = 0.01). Proportioned alignment in GAP SP with disproportioned alignment in GAP LDI contributed to an increased risk of PJK and PJF (OR 2.67, 95% CI 1.95-6.82, p = 0.045). There was no significant association of GAP SP proportionality and GAP RPV (OR 1.1, 0.86-2.15, p = 0.253) or GAP LL (OR 1.34, 0.78-4.23, p = 0.673) disproportionality with outcomes. Disproportioned alignment in GAP SP but proportioned alignment in both GAP LL and GAP LDI was associated with decreased likelihood of PJK (OR 0.53, 95% CI 0.39-0.94, p = 0.02) and PJF (OR 0.31, 95% CI 0.19-0.67, p = 0.001). CONCLUSION: The spinopelvic component of the GAP score is the most significant independent predictor of clinical outcomes. Its interaction with the other components of the GAP score also aids assessment of the risk for mechanical complications.

High-Impact Chronic Pain Transition in Lumbar Surgery Recipients.

OBJECTIVE: High-impact chronic pain (HICP) is a term that characterizes the presence of a severe and troubling pain-related condition. To date, the prevalence of HICP in lumbar spine surgery recipients and their HICP transitions from before to after surgery are unexplored. The purpose was to define HICP prevalence, transition types, and outcomes in lumbar spine surgery recipients and to identify predictors of HICP outcomes. METHODS: In total, 43,536 lumbar surgery recipients were evaluated for HICP transition. Lumbar spine surgery recipients were categorized as having HICP preoperatively and at 3 months after surgery if they exhibited chronic and severe pain and at least one major activity limitation. Four HICP transition groups (Stable Low Pain, Transition from HICP, Transition to HICP, and Stable High Pain) were categorized and evaluated for outcomes. Multivariate multinomial modeling was used to predict HICP transition categorization. RESULTS: In this sample, 15.1% of individuals exhibited HICP preoperatively; this value declined to 5.1% at 3 months after surgery. Those with HICP at baseline and 3 months had more comorbidities and worse overall outcomes. Biological, psychological, and social factors predicted HICP transition or Stable High Pain; some of the strongest involved social factors of 2 or more to transition to HICP (OR = 1.43; 95% CI = 1.21-1.68), and baseline report of pain/disability (OR = 3.84; 95% CI = 3.20-4.61) and psychological comorbidity (OR = 1.78; 95% CI = 1.48-2.12) to Stable Stable High Pain. CONCLUSION: The percentage of individuals with HICP preoperatively (15.1%) was low, which further diminished over a 3-month period (5.1%). Postoperative HICP groups had higher levels of comorbidities and worse baseline outcomes scores. Transition to and maintenance of HICP status was predicted by biological, psychological, and social factors.

How dimensions can guide surgical planning and training: a systematic review of Kambin's triangle.

OBJECTIVE: The authors sought to analyze the current literature to determine dimensional trends across the lumbar levels of Kambin's triangle, clarify the role of imaging techniques for preoperative planning, and understand the effect of inclusion of the superior articular process (SAP). This compiled knowledge of the triangle is needed to perform successful procedures, reduce nerve root injuries, and help guide surgeons in training. METHODS: The authors performed a search of multiple databases using combinations of keywords: Kambin's triangle, size, measurement, safe triangle, and bony triangle. Articles were included if their main findings included measurement of Kambin's triangle. The PubMed, Scopus, Ovid, Cochrane, Embase, and Medline databases were systematically searched for English-language articles with no time frame restrictions through July 2022. RESULTS: Eight studies comprising 132 patients or cadavers were included in the study. The mean ± SD age was 66.69 ± 9.6 years, and 53% of patients were male. Overall, the size of Kambin's triangle increased in area moving down vertebral levels, with L5-S1 being the largest (133.59 ± 4.36 mm2). This trend followed a linear regression model when SAP was kept (p = 0.008) and removed (p = 0.003). There was also a considerable increase in the size of Kambin's triangle if the SAP was removed. CONCLUSIONS: Here, the authors have provided the first reported systematic review of the literature of Kambin's triangle, its measurements at each lumbar level, and key areas of debate related to the definition of the working safe zone. These findings indicate that CT is heavily utilized for imaging of the safe zone, the area of Kambin's triangle tends to increase caudally, and variation exists between patients. Future studies should focus on using advanced imaging techniques for preoperative planning and establishing guidelines for surgeons.

Treatment of L5-S1 spondyloptosis with stand-alone anterior lumbar interbody fusion in a patient with neurofibromatosis.

BACKGROUND: Neurofibromatosis type 1 (NF1) is a multisystem disorder that causes multiple tumor formations throughout the nervous system. Common spinal dysplasias seen with NF1, such as dural ectasia (DE), often undergo modulation and predispose these patients to spondylolisthesis, making surgical treatment challenging. CASE DESCRIPTION: A patient with NF1 presented with a 12-year-history of back and left lower extremity radicular pain. Lumbar spine magnetic resonance imaging revealed developmental anomalies with severe DE and associated scalloping of the L4-S1 vertebral bodies and severe L5-S1 Meyerding grade 4 spondylolisthesis. During surgery, post-positioning x-rays demonstrated a grade 5 spondyloptosis. The patient underwent an L5-S1 stand-alone anterior lumbar interbody fusion (ALIF). The final construct was an ALIF cage with one screw into S1, without an anterior plate. By 3-months post-operative, there was complete resolution of preoperative symptoms and at 2 year follow-up the patient was asymptomatic with stable hardware and solid bony fusion. To the authors' knowledge, this is the first report of spondyloptosis treated with a stand-alone ALIF in a patient with NF1 and severe DE.

Single-position prone transpsoas fusion for the treatment of lumbar adjacent segment disease: early experience of twenty-four cases across three tertiary medical centers.

PURPOSE: Prone transpsoas fusion (PTP) is a minimally invasive technique that maximizes the benefit of lateral access interbody surgery and the prone positioning for surgically significant adjacent segment disease. The authors describe the feasibility, reproducibility and radiographic efficacy of PTP when performed for cases of lumbar ASD. METHODS: Adult patients undergoing PTP for treatment of lumbar ASD at three institutions were retrospectively enrolled. Demographic information was recorded, as was operative data such as adjacent segment levels, operative time, blood loss, laterality of approach, open versus percutaneous pedicle screw instrumentation and need for primary decompression. Radiographic measurements including segmental and global lumbar lordosis, pelvic incidence, pelvic tilt, sacral slope and sagittal vertical axis were recorded both pre- and immediately post-operatively. RESULTS: Twenty-four patients met criteria for inclusion. Average age was 60.4 ± 10.4 years and average BMI was 31.6 ± 5.0 kg/m2. Total operative time was 204.7 ± 83.3 min with blood loss of 187.9 ± 211 mL. Twenty-one patients had pedicle screw instrumentation exchanged percutaneously and 3 patients had open pedicle screw exchange. Two patients suffered pulmonary embolism that was treated medically with no long-term sequelae. One patient had transient lumbar radicular pain and all patients were discharged home with an average length of stay of 3.0 days (range 1-6). Radiographically, global lumbar lordosis improved by an average of 10.3 ± 9.0 degrees, segmental lordosis by 10.1 ± 13.3 degrees and sagittal vertical axis by 3.2 ± 3.2 cm. CONCLUSION: Single-position prone transpsoas lumbar interbody fusion is a clinically reproducible minimally invasive technique that can effectively treat lumbar adjacent segment disease.

Pseudarthrosis rate following anterior cervical discectomy with fusion using an allograft cellular bone matrix: a multi-institutional analysis.

OBJECTIVE: The use of osteobiologics, engineered materials designed to promote bone healing by enhancing bone growth, is becoming increasingly common for spinal fusion procedures, but the efficacy of some of these products is unclear. The authors performed a retrospective, multi-institutional study to investigate the clinical and radiographic characteristics of patients undergoing single-level anterior cervical discectomy with fusion performed using the osteobiologic agent Osteocel, an allograft mesenchymal stem cell matrix. METHODS: The medical records across 3 medical centers and 12 spine surgeons were retrospectively queried for patients undergoing single-level anterior cervical discectomy and fusion (ACDF) with the use of Osteocel. Pseudarthrosis was determined based on CT or radiographic imaging of the cervical spine. Patients were determined to have radiographic pseudarthrosis if they met any of the following criteria: 1) lack of bridging bone on CT obtained > 300 days postoperatively, 2) evidence of instrumentation failure, or 3) motion across the index level as seen on flexion-extension cervical spine radiographs. Univariate and multivariate analyses were then performed to identify independent preoperative or perioperative predictors of pseudarthrosis in this population. RESULTS: A total of 326 patients met the inclusion criteria; 43 (13.2%) patients met criteria for pseudarthrosis, of whom 15 (34.9%) underwent revision surgery. There were no significant differences between patients with and those without pseudarthrosis, respectively, for patient age (54.1 vs 53.8 years), sex (34.9% vs 47.4% male), race, prior cervical spine surgery (37.2% vs 33.6%), tobacco abuse (16.3% vs 14.5%), chronic kidney disease (2.3% vs 2.8%), and diabetes (18.6% vs 14.5%) (p > 0.05). Presence of osteopenia or osteoporosis (16.3% vs 3.5%) was associated with pseudarthrosis (p < 0.001). Implant type was also significantly associated with pseudarthrosis, with a 16.4% rate of pseudarthrosis for patients with polyetherethereketone (PEEK) implants versus 8.4% for patients with allograft implants (p = 0.04). Average lengths of follow-up were 27.6 and 23.8 months for patients with and those without pseudarthrosis, respectively. Multivariate analysis demonstrated osteopenia or osteoporosis (OR 4.97, 95% CI 1.51-16.4, p < 0.01) and usage of PEEK implant (OR 2.24, 95% CI 1.04-4.83, p = 0.04) as independent predictors of pseudarthrosis. CONCLUSIONS: In patients who underwent single-level ACDF, rates of pseudarthrosis associated with the use of the osteobiologic agent Osteocel are higher than the literature-reported rates associated with the use of alternative osteobiologics. This is especially true when Osteocel is combined with a PEEK implant.

Interhospital transfer status for spinal metastasis patients in the United States is associated with more severe clinical presentations and higher rates of inpatient complications.

OBJECTIVE: In patients with metastatic spinal disease (MSD), interhospital transfer can potentially impact clinical outcomes as the possible benefits of transferring a patient to a higher level of care must be weighed against the negative effects associated with potential delays in treatment. While the association of clinical outcomes and transfer status has been examined in other specialties, the relationship between transfer status, complications, and risk of mortality in patients with MSD has yet to be explored. The purpose of this study was to examine the impact of transfer status on in-hospital mortality and clinical outcomes in patients diagnosed with MSD. METHODS: The National (Nationwide) Inpatient Sample (NIS) database was retrospectively queried for adult patients diagnosed with vertebral pathological fracture and/or spinal cord compression in the setting of metastatic disease between 2012 and 2014. Demographics, baseline characteristics (e.g., metastatic spinal cord compression [MSCC] and paralysis), comorbidities, type of intervention, and relevant patient outcomes were controlled in a multivariable logistic regression model to analyze the association of transfer status with patient outcomes. RESULTS: Within the 10,360 patients meeting the inclusion and exclusion criteria, higher rates of MSCC (50.2% vs 35.9%, p < 0.001) and paralysis (17.3% vs 8.4%, p < 0.001) were observed in patients transferred between hospitals compared to those directly admitted. In univariable analysis, a higher percentage of transferred patients underwent surgical intervention (p < 0.001) when compared with directly admitted patients. After controlling for significant covariates and surgical intervention, transferred patients were more likely to develop in-hospital complications (OR 1.34, 95% CI 1.18-1.52, p < 0.001), experience prolonged length of stay (OR 1.33, 95% CI 1.16-1.52, p < 0.001), and have a discharge disposition other than home (OR 1.70, 95% CI 1.46-1.98, p < 0.001), with no significant difference in inpatient mortality rates. CONCLUSIONS: Patients with MSD who were transferred between hospitals demonstrated more severe clinical presentations and higher rates of inpatient complications compared to directly admitted patients, despite demonstrating no difference in in-hospital mortality rates.

Robotic-assisted percutaneous iliac screw fixation for destructive lumbosacral metastatic lesions: an early single-institution experience.

BACKGROUND: Robotic-assisted surgery is becoming more widely applied in surgical subspecialties due to its intraoperative and postoperative advantages such as minimally invasive approach, reduced blood loss, shorter hospital stay, and decreased incidence of postoperative complications. However, robotic devices were only recently introduced in the field of spinal surgery. Specifically, percutaneous approaches involving computer-assisted image guidance are relatively new in iliac screw fixation. Previous methods focused on the use of S2-alar-iliac (S2AI) screw fixation which allows for pelvic fixation without a need for side connectors. However, for patients with destructive lesions of the sacrum, placement of these S2AI screws may not be feasible. The purpose of this technical note is to illustrate the implementation of robotic-assisted percutaneous iliac screw fixation in two cases which allows for minimally invasive attachment to the proximal lumbar screws without a side connector and eliminates a potential source of instrumentation failure. METHODS: Robotic-assisted percutaneous iliac screw fixation was performed on two patients. The robotics system was used to merge the fluoroscopic images with intraoperative computed tomography (CT) images to plan the trajectories for placement of bilateral pedicle and iliac screws. Intraoperative CT scan was again performed to confirm proper placement of all screws. Rods were then engaged bilaterally with the pedicle and iliac screws without the use of side connectors. RESULTS: The patients did not experience immediate postoperative complications and had stable hardware at one-month follow-up. Our cases demonstrate the surgical efficiency of robotic-assisted lumbo-iliac instrumentation which obviates the need to use a side connector, which is commonly used in iliac fixation. This eliminates a step, which can reduce the possibility of instrumentation failure. CONCLUSION: Robotic-assisted percutaneous iliac screw fixation is a safe and feasible technique to improve operative and clinical outcomes in complex spinal instrumentation surgeries.

The medicolegal impact of misplaced pedicle and lateral mass screws on spine surgery in the United States.

Spine surgery has been disproportionately impacted by medical liability and malpractice litigation, with the majority of claims and payouts related to procedural error. One common area for the potential avoidance of malpractice claims and subsequent payouts involves misplaced pedicle and/or lateral mass instrumentation. However, the medicolegal impact of misplaced screws on spine surgery has not been directly reported in the literature. The authors of the current study aimed to describe this impact in the United States, as well as to suggest a potential method for mitigating the problem.This retrospective analysis of 68 closed medicolegal cases related to misplaced screws in spine surgery showed that neurosurgeons and orthopedic spine surgeons were equally named as the defendant (n = 32 and 31, respectively), and cases were most commonly due to misplaced lumbar pedicle screws (n = 41, 60.3%). Litigation resulted in average payouts of $1,204,422 ± $753,832 between 1995 and 2019, when adjusted for inflation. The median time to case closure was 56.3 (35.2-67.2) months when ruled in favor of the plaintiff (i.e., patient) compared to 61.5 (51.4-77.2) months for defendant (surgeon) verdicts (p = 0.117).

IgG4-related disease presenting as intradural extramedullary lesion: a case report and review of the literature.

Object: IgG4-related disease (IgG4-RD) is a fibro-inflammatory disorder affecting various anatomical sites, and only recently was identified to affect the dura of the spine. The authors present the second reported case of an intradural extramedullary lesion consistent with IgG4-related spinal disease. Methods: A literature review was performed that identified 15 other cases of spinal disease, and common features of all known reported spinal IgG4-RD are discussed. Results: Spinal IgG4-RD typically affects males of approximately 50 years of age, and often presents as a T1 and T2 hypo- or isointense lesion that homogenously enhances. Surgical intervention typically involves subtotal resection or biopsy, and histopathologic findings include increased IgG4-positive cells or an IgG4:IgG ratio >40%. The disease responds well to steroids early on, and treatment can include adjuvant therapy such as azathioprine. Conclusions: Systemic involvement is possible, and, early treatment can quickly minimize disease burden. Thus, increased suspicion would result in early diagnosis and improved prognosis.

Two-level reverse Bohlman transsoseous approach for treatment of symptomatic pseudarthrosis.

Surgical treatment for high-grade spondylolisthesis with high sacral slope remains controversial and no definitive gold standard procedure has been identified. The Bohlman technique, in which a fibular strut is reamed posteriorly across the L5-S1 disc space in an oblique, inferior to superior trajectory, has been increasingly utilized. Recently, a Reverse Bohlman technique has been described, in which a graft is reamed anteriorly across a single disc space in a superior to inferior trajectory. Case Report A 55 year-old male with complete lumbarization of S1 (referred to as L6) and previous L5-L6-S1 posterior instrumented fusion presented, with progressively worsening low back pain and lower extremity radicular pain. After failing conservative management, he underwent a 2-level Reverse Bohlman approach to place a titanium mesh interbody graft (cage) anteriorly from L5 to S1, crossing the L5-6 and L6-S1 disc spaces. Here we describe for the first time a Reverse Bohlman technique spanning two disc spaces in a patient with a transitional lumbosacral anomaly and high sacral slope. At 6 months post-operative follow up, the patient reported near complete resolution of symptoms.

Complication rates associated with open versus percutaneous pedicle screw instrumentation among patients undergoing minimally invasive interbody fusion for adult spinal deformity.

OBJECTIVE High-quality studies that compare outcomes of open and minimally invasively placed pedicle screws for adult spinal deformity are needed. Therefore, the authors compared differences in complications from a circumferential minimally invasive spine (MIS) surgery and those from a hybrid surgery. METHODS A retrospective review of a multicenter database of patients with spinal deformity who were treated with an MIS surgery was performed. Database inclusion criteria included an age of ≥ 18 years and at least 1 of the following: a coronal Cobb angle of > 20°, a sagittal vertical axis of > 5 cm, a pelvic incidence-lumbar lordosis angle of > 10°, and/or a pelvic tilt of > 20°. Patients were propensity matched according to the levels instrumented. RESULTS In this database, a complete data set was available for 165 patients, and after those who underwent 3-column osteotomy were excluded, 137 patients were available for analysis; 76 patients remained after propensity matching (MIS surgery group 38 patients, hybrid surgery group 38 patients). The authors found no difference in demographics, number of levels instrumented, or preoperative and postoperative radiographic results. At least 1 complication was suffered by 55.3% of patients in the hybrid surgery group and 44.7% of those in the MIS surgery group (p = 0.359). Patients in the MIS surgery group had significantly fewer neurological, operative, and minor complications than those in the hybrid surgery group. The reoperation rates in both groups were similar. The most common complication category for the MIS surgery group was radiographic and for the hybrid surgery group was neurological. Patients in both groups experienced postoperative improvement in their Oswestry Disability Index and visual analog scale (VAS) back and leg pain scores (all p < 0.05); however, MIS surgery provided a greater reduction in leg pain according to VAS scores. CONCLUSIONS Overall complication rates in the MIS and hybrid surgery groups were similar. MIS surgery resulted in significantly fewer neurological, operative, and minor complications. Reoperation rates in the 2 groups were similar, and despite complications, the patients reported significant improvement in their pain and function.

Failure of a polyether-ether-ketone expandable interbody cage following transforaminal lumbar interbody fusion.

PURPOSE: Expandable cages are a more recent option for maintaining or restoring disc height and segmental lordosis with transforaminal lumbar interbody fusion (TLIF). Complications associated with expandable cages have not yet been widely reported. We report a case of postoperative failure of a polyether-ether-ketone (PEEK) expandable interbody device used during TLIF. METHODS: A 50-year-old man presented with severe back and right leg pain after undergoing L4-5 and L5-S1 TLIFs with expandable cages and L3-S1 posterior instrumented fusion. Imaging showed retropulsion of a portion of the interbody cage into the spinal canal causing nerve compression. Displacement occurred in a delayed manner. In addition, pseudoarthrosis was present. RESULTS: The patient underwent re-exploration with removal of the retropulsed wafer and redo fusion. CONCLUSIONS: Expandable cages are a recent innovation; as such, efficacy and complication data are limited. As with any new device, there exists potential for mechanical failure, as occurred in the case presented.

Comparison of minimally invasive transspinous and open approaches for thoracolumbar intradural-extramedullary spinal tumors.

OBJECT Spinal tumor resection has historically been performed via open approaches, although minimally invasive approaches have recently been found to be effective in small cohort series. The authors compare surgical characteristics and clinical outcomes of surgery in patients undergoing mini-open and open approaches for intradural-extramedullary tumor resection. METHODS The authors retrospectively reviewed 65 consecutive intradural-extramedullary tumor resections performed at their institution from 2007 to 2014. Patients with cervical tumors or pathology demonstrating neurofibroma were excluded (n = 14). The nonparametric Mann-Whitney U-test and Pearson chi-square test were used to compare continuous and categorical variables, respectively. Statistical analyses were performed using SPSS, with significance set at p < 0.05. RESULTS Fifty-one thoracolumbar intradural-extramedullary tumor resections were included; 25 were performed via the minimally invasive transspinous approach. There were no statistically significant differences in age, sex, body mass index, preoperative American Spinal Injury Association (ASIA) score, preoperative symptom duration, American Society of Anesthesiologists (ASA) physical status class, tumor size, or tumor location. There was no statistically significant difference between groups with respect to the duration of the operation or extent of resection, but the mean estimated blood loss was significantly lower in the minimally invasive surgery (MIS) cohort (142 vs 320 ml, p < 0.05). In each group, the 2 most common tumor pathologies were schwannoma and meningioma. There were no statistically significant differences in length of hospitalization, ASIA score improvement, complication rate, or recurrence rate. The mean duration of follow-up was 2 years for the MIS group and 1.6 years for the open surgery group. CONCLUSIONS This is one of the largest comparisons of minimally invasive and open approaches to the resection of thoracolumbar intradural-extramedullary tumors. With well-matched cohorts, the minimally invasive transspinous approach appears to be as safe and effective as the open technique, with the advantage of significantly reduced intraoperative blood loss.

Sleep apnea and cervical spine pathology.

PURPOSE: Sleep apnea is a multi-factorial disease with a variety of identified causes. With its close proximity to the upper airway, the cervical spine and its associated pathologies can produce sleep apnea symptoms in select populations. The aim of this article was to summarize the literature discussing how cervical spine pathologies may cause sleep apnea. METHODS: A search of the PubMed database for English-language literature concerning the cervical spine and its relationship with sleep apnea was conducted. Seventeen published papers were selected and reviewed. RESULTS: Single-lesion pathologies of the cervical spine causing sleep apnea include osteochondromas, osteophytes, and other rare pathologies. Multifocal lesions include rheumatoid arthritis of the cervical spine and endogenous cervical fusions. Furthermore, occipital-cervical misalignment pre- and post-cervical fusion surgery may predispose patients to sleep apnea. CONCLUSIONS: Pathologies of the cervical spine present significant additional etiologies for producing obstructive sleep apnea in select patient populations. Knowledge of these entities and their pathophysiologic mechanisms is informative for the clinician in diagnosing and managing sleep apnea in certain populations.

Independent predictors for local recurrence following surgery for spinal metastasis.

BACKGROUND: Local recurrence of spinal metastasis after surgical resection is relatively common. We sought to determine risk factors and independent predictors for local recurrence after primary surgical resection of spinal metastasis. METHODS: Demographic and clinical variables were collected for patients who underwent surgery for spinal metastasis June 2005 to June 2011. Primary outcome of interest was local recurrence. Significant associations between covariates of interest and recurrence were identified using the chi-square test. Multivariable logistic regression models for recurrence risk were fit and adjusted for potential confounders. RESULTS: A total of 99 patients were analyzed. Mean time to metastatic recurrence was 9.8 months. Thirty-two patients (32.3 %) had local recurrence of metastatic disease following initial surgery. Patients who underwent radiotherapy had significantly higher recurrence rates than patients who did not (39.2 % vs. 12.0 %, respectively; P = 0.012). Patients with metastatic disease affecting more levels had significantly lower recurrence rates. On multivariate analysis, older age was an independent predictor of decreased likelihood of local recurrence. Melanoma was the only cancer type independently associated with higher risk for recurrence. Patients with recurrence had significantly higher 1- and 2-year survival rates than patients without recurrence. Median length of survival was longer in the recurrent group as well. CONCLUSIONS: Other than melanoma, covariates significantly associated with recurrence were factors likely associated with increased survival, including less-extensive spinal disease and radiotherapy. Thus, longer survival time following surgery likely results in a greater chance for local recurrence. As advancements in treatment provide prolonged survival, local recurrence rates will likely increase.

Proximal lumbar anterior column realignment for iatrogenic sagittal plane adult spinal deformity correction: a retrospective case series.

BACKGROUND AND OBJECTIVES: Anterior column realignment (ACR) is a powerful minimally invasive surgery (MIS) technique to restore sagittal alignment in adult spinal deformity (ASD). This can accomplish similar segmental lordosis restoration as 3-column osteotomy with less blood loss and comparable complication rates. ACR can be performed at adjacent disease segments in the proximal lumbar spine in revision cases. However, two-thirds of physiologic lordosis occurs between L4-S1, and concerns remain about altered lumbar morphology. We evaluated patients who underwent proximal lumbar ACR for iatrogenic flatback deformity. METHODS: A total of 19 consecutive patients who underwent L1-2 or L2-3 ACR were retrospectively analyzed. All patients were treated with lateral MIS interbody technique, followed by posterior reconstruction with Smith-Peterson osteotomy (SPO). Pre- and post-operative radiographic and clinical outcomes were obtained. RESULTS: Mean follow-up was 19-months. All but one patient had a history of prior lumbar or lumbo-sacral fusion. SVA and PI-LL decreased from 11.9 cm to 6.1 cm (p<0.0001) and 34.2° to 12.8° (p<0.0001). Segmental lordosis increased from -2.7° to 21.9° (p<0.0001). Proximal lumbar lordosis (PLL) increased from -0.4° to 22.6° (p<0.0001), and lordosis distribution index (LDI) decreased from 79.5% to 48.9% (p<0.0001). Mean ODI and NPRS back pain decreased from 58.0 to 36.2 (p=0.0041) and 7.9 to 3.4 (p<0.0001). PROMIS-10 Physical and Mental Health T-scores increased from 34.1 to 43.3 (p=0.0049) and 40.4 to 45.0 (p=0.0993). Major complication rate was 15.8%. One patient required revision for mechanical failure. There were no permanent neurological or vascular injuries. CONCLUSION: Proximal lumbar ACR plus SPO can achieve sagittal correction with low major complication rates in patients with ASD and prior distal fusion. Differentially increasing PLL and lowering LDI did not have deleterious effects on radiographic or clinical outcomes. Further work is needed to understand the effect of proximal ACR in the surgical management of ASD.

Advancing Prone-Transpsoas Spine Surgery: A Narrative Review and Evolution of Indications with Representative Cases.

The Prone Transpsoas (PTP) approach to lumbar spine surgery, emerging as an evolution of lateral lumbar interbody fusion (LLIF), offers significant advantages over traditional methods. PTP has demonstrated increased lumbar lordosis gains compared to LLIF, owing to the natural increase in lordosis afforded by prone positioning. Additionally, the prone position offers anatomical advantages, with shifts in the psoas muscle and lumbar plexus, reducing the likelihood of postoperative femoral plexopathy and moving critical peritoneal contents away from the approach. Furthermore, operative efficiency is a notable benefit of PTP. By eliminating the need for intraoperative position changes, PTP reduces surgical time, which in turn decreases the risk of complications and operative costs. Finally, its versatility extends to various lumbar pathologies, including degeneration, adjacent segment disease, and deformities. The growing body of evidence indicates that PTP is at least as safe as traditional approaches, with a potentially better complication profile. In this narrative review, we review the historical evolution of lateral interbody fusion, culminating in the prone transpsoas approach. We also describe several adjuncts of PTP, including robotics and radiation-reduction methods. Finally, we illustrate the versatility of PTP and its uses, ranging from 'simple' degenerative cases to complex deformity surgeries.

So Close yet So Far: The impact of undercorrection of cervical sagittal alignment during adult cervical deformity surgery - An Incremental correction analysis.

BACKGROUND: To compare degrees of cSVA correction and to theorize possible minimum and maximum thresholds of cSVA correction for patients to benefit clinically. METHODS: 657 operative ACD patients in a retrospective cohort study of a prospectively enrolled database with complete baseline and two year radiographic and HRQL data were examined. Patients were grouped into an optimally corrected cohort (OC; postop cSVA ≤ 4 cm) and an undercorrected cohort (UC; postop cSVA > 4 cm) based on postoperative radiographs. RESULTS: 265 patients met inclusion criteria (mean age 58.2 ± 11.4 years, BMI 28.9 ± 7.5, CCI 0.9 ± 1.3). 11.2 % of patients were UC, while 88.8 % of patients were OC. UC cohort experienced a significantly greater occurrence of radiographic complications (47.8 % v. 27.6 %, p = 0.046). UC also demonstrated a significantly greater rate of severe 6 M DJK (p < 0.001) and 1Y DJK (26.1 % v. 2.7 %, p < 0.001). In terms of HRQLs, the OC cohort demonstrated significantly greater 2Y EQ5D-Health values (76.9 v. 46.7, p = 0.012). Being UC was a significant predictor of moderate-high 1Y mJOA score (OR 3.0, CI 95 % 1.2-7.3, p = 0.015) Still, in terms of CIT, the threshold for DJF risk increased significantly (p = 0.026) when the cSVA were surgically corrected greater than 5 cm. CONCLUSION: Undercorrection of cSVA yielded worse clinical outcomes and posed a significant risk for radiographic complications. Although undercorrection does not seem to be efficacious, surgical correction beyond certain thresholds should still be respected as there is a risk for DJK on either end of the spectrum.

Clinical and radiographic outcomes after index anterior cervical discectomy and fusion with interbody spacer with integrated anchor fixation: a single-surgeon case study.

Background: The use of plate-cage systems in anterior cervical discectomy and fusion (ACDF) has been shown to produce fusion and good clinical outcomes though it has been associated with complications such as dysphagia at higher rates than stand-alone implant devices. This study aimed to assess the incidence of dysphagia and radiographic outcomes in adult patients who have undergone ACDF with interbody spacer with integrated anchor fixation (ISa). Methods: Patients who underwent index ACDF with a commercially available ISa by a fellowship-trained spine surgeon between January 2018 and December 2021 were retrospectively included. Patients with less than 90-days follow-up or those who underwent ACDF for trauma, infection, or tumor were excluded. Demographic data, perioperative data, radiographic data and perioperative complications were collected. Results: Forty-five patients were included for study. Eight patients (17.8%) experienced dysphagia immediately following surgery, which resolved by 6 months post-op, barring 1 patient. Preoperative global and segmental lordosis were 10.4°±9.3° and 6.9°±7.3° respectively. At three months postoperatively, global and segmental lordosis were 8.9°±7.9° (P=0.50) and 7.0°±5.9° (P=0.56) respectively. Fusion rate at six months was 78.3% (18/23) and 100% (18/18) at 1 year. Conclusions: ACDF with ISa is a viable alternative to traditional plate-cage systems. ISa shows lower rates of immediate, 3-month and 6-month dysphagia than traditional plate-cage systems described in the literature. More controlled studies on larger populations will help formulate a concrete conclusion on the advantages of ISa spacers.