Developing a risk score to inform the use of rhBMP-2 in adult spinal deformity surgery.

BACKGROUND: Recombinant human bone morphogenetic protein-2 (rhBMP-2) has not shown superior benefit overall in cost-effectiveness during adult spinal deformity (ASD) surgery. STUDY DESIGN/SETTING: Retrospective PURPOSE: Generate a risk score for pseudarthrosis to inform the utilization of rhBMP-2, balancing costs against quality of life and complications. METHODS: ASD patients with 3-year data were included. Quality of life gained was calculated from ODI to SF-6D and translated to quality-adjusted life years (QALYs). Cost was calculated using the PearlDiver database and CMS definitions for complications and comorbidities. Established weights were generated for predictive variables via logistic regression to yield a predictive risk score for pseudarthrosis that accounted for frailty, diabetes, depression, ASA grade, thoracolumbar kyphosis and three-column osteotomy use. Risk score categories, established via conditional inference tree (CIT)-derived thresholds were tested for cost-utility of rhBMP-2 usage, controlling for age, prior fusion, and baseline deformity and disability. RESULTS: 64% of ASD patients received rhBMP-2 (308/481). There were 17 (3.5%) patients that developed pseudarthrosis. rhBMP-2 use overall did not lower pseudarthrosis rates (OR: 0.5, [0.2-1.3]). Pseudarthrosis rates for each risk category were: No Risk (NoR) 0%; Low-Risk (LowR) 1.6%; Moderate Risk (ModR) 9.3%; High-Risk (HighR) 24.3%. Patients receiving rhBMP-2 had similar QALYs overall to those that did not (0.163 vs. 0.171, p = .65). rhBMP-2 usage had worse cost-utility in the LowR cohort (p < .001). In ModR patients, rhBMP-2 usage had equivocal cost-utility ($53,398 vs. $61,581, p = .232). In the HighR cohort, the cost-utility was reduced via rhBMP-2 usage ($98,328 vs. $211,091, p < .001). CONCLUSION: Our study shows rhBMP-2 demonstrates effective cost-utility for individuals at high risk for developing pseudarthrosis. The generated score can aid spine surgeons in the assessment of risk and enhance justification for the strategic use of rhBMP-2 in the appropriate clinical contexts. LEVEL OF EVIDENCE: III.

Early Experience with Prone Lateral Interbody Fusion in Deformity Correction: A Single-Institution Experience.

Background/Objectives: Lateral spine surgery offers effective minimally invasive deformity correction, but traditional approaches often involve separate anterior, lateral, and posterior procedures. The prone lateral technique streamlines this process by allowing single-position access for lateral and posterior surgery, potentially benefiting from the lordosing effect of prone positioning. While previous studies have compared prone lateral to direct lateral for adult degenerative diseases, this retrospective review focuses on the outcomes of adult deformity patients undergoing prone lateral interbody fusion. Methods: Ten adult patients underwent single-position prone lateral surgery for spine deformity correction, with a mean follow-up of 18 months. Results: Results showed significant improvements: sagittal vertical axis decreased by 2.4 cm, lumbar lordosis increased by 9.1°, pelvic tilt improved by 3.3°, segmental lordosis across the fusion construct increased by 12.2°, and coronal Cobb angle improved by 6.3°. These benefits remained consistent over the follow-up period. Correlational analysis showed a positive association between improvements in PROs and SVA and SL. When compared to hybrid approaches, prone lateral yielded greater improvements in SVA. Conclusions: Prone lateral surgery demonstrated favorable outcomes with reasonable perioperative risks. However, further research comparing this technique with standard minimally invasive lateral approaches, hybrid, and open approaches is warranted for a comprehensive evaluation.

Osteoimmunology: Interactions With the Immune System in Spinal Fusion.

Spinal fusion is important for the clinical success of patients undergoing surgery, and the immune system plays an increasingly recognized role. Osteoimmunology is the study of the interactions between the immune system and bone. Inflammation impacts the osteogenic, osteoconductive, and osteoinductive properties of bone grafts and substitutes and ultimately influences the success of spinal fusion. Macrophages have emerged as important cells for coordinating the immune response following spinal fusion surgery, and macrophage-derived cytokines impact each phase of bone graft healing. This review explores the cellular and molecular immune processes that regulate bone homeostasis and healing during spinal fusion.

Clinical and Radiographic Outcomes for Patients with Cervical Adjacent Segment Disease Treated with Anterior Cervical Discectomy and Fusion with Integrated Interbody Spacers.

INTRODUCTION: Anterior cervical discectomy and fusion (ACDF) is among the most common spine procedures. Adjacent segment disease (ASD), characterized by degenerative disease at an adjacent spinal level to a prior fusion, is a well-recognized and significant sequela following ACDF. Adjacent segment ACDF may be considered after the failure of non-surgical options for patients with symptomatic ASD. This study aimed to assess the incidence of dysphagia and other complications as well as radiographic outcomes in adult patients who have undergone ACDF with an integrated interbody spacer device for symptomatic ASD. METHODS: This was a retrospective review of patients who underwent ACDF for symptomatic ASD with commercially available integrated interbody spacers by three spine surgeons at an academic institution from March 2018 to April 2022. Demographic, radiographic, and postoperative data were collected, including dysphagia, device-related complications, and the need for revision surgery. RESULTS: There were 48 patients (26 male, 22 female) who met inclusion criteria (mean age 59.7 years, mean body mass index 19.5 kg/m2) who underwent ACDF for symptomatic ASD (1one-level, n = 44; 2-level, n = 4). Overall, 12 patients (25%) experienced dysphagia postoperatively before the first follow-up appointment. Nine of 44 (20.4%) of 1-level ACDF patients experienced dysphagia, and 3 of 4 (75%) of 2-level ACDF patients experienced dysphagia. Three patients had severe dysphagia which prompted an otolaryngology referral. Two of those patients remained symptomatic at 6 weeks postoperatively. Of 43 patients with prior plate cage systems, none required hardware removal at the time of surgery. Preoperative global and segmental lordosis were 9.07° ± 8.36° (P = 0.22) and 3.58° ± 4.57° (P = 0.14), respectively. At 6 weeks postoperatively, global and segmental lordosis were 11.44° ± 9.06° (P = 0.54) and 5.11° ± 4.44° (P = 0.44), respectively. This constitutes a change of +2.37° and +1.53° in global and segmental lordosis, respectively. The mean anterior disc height change between preoperative and immediate postoperative time points was 6.3 ± 3.1 mm. Between the immediate postoperative and 6-week postoperative time points, the mean anterior disc height change was -1.5 ± 2.7 mm. Between the immediate postoperative and 3-month postoperative time points, the mean anterior disc height change was -3.7 ± 5.0 mm. The posterior disc height changes at the same time points were 2.5 ± 1.7 mm, -0.4 ± 1.8. and -0.5 ± 1.4 mm, respectively. This fusion rate was 50% and 70% at 6 months and 1 year post-surgery, respectively. CONCLUSIONS: ACDF with integrated spacer is a viable alternative to traditional plate-cage systems for symptomatic ASD. An advantage over traditional plate-cage systems is that the removal of prior instrumentation is not needed in order to place implants. Based on a review of the literature, these standalone systems allowed for a shorter operative time and had less incidence of dysphagia than plate-cage systems for ASD after ACDF. The different standalone and plate-cage systems used in treating ASD after ACDF surgeries should be compared in prospective studies.

Two-Level Minimally Invasive Lumbar Laminectomy and Foraminotomy: 2-Dimensional Operative Video.

Minimally invasive lumbar laminectomies utilize tubular retractors to minimize tissue disturbance, blood loss, and hospital length of stay compared to open operations. Here, we highlight the operative treatment of a 68-yr-old male entailing a 2-level minimally invasive lumbar laminectomy and foraminotomy at L2-L3 and L3-L4. The patient initially presented with symptoms of treatment-refractory lower extremity numbness and limited ambulation. His imaging demonstrated coronal scoliosis and severe lumbar central and foraminal stenosis at L2-L3 and L3-L4, with enlarged spinous processes, laminae, and facets. The patient consented to the procedure and publication of their image. The operation proceeded with the patient in a prone position with paramedian dissection to the lamina through a minimally invasive tubular retractor. Laminectomies and foraminotomies were performed at each level with high-speed drill and a Kerrison rongeur, with care to identify and protect the relevant spinal nerve roots. Postoperatively, the patient reported significantly reduced numbness and improved ambulation, with a well-healed surgical incision notably smaller than those produced in an open operation.

Minimally Invasive Management of Civilian Gunshot Wounds to the Lumbar Spine: A Case Series and Technical Report.

BACKGROUND: Treatment of penetrating gunshot wounds (GSW) to the spine remains controversial. The decision to operate is often based on surgeon preference and experience. We present a case series of 7 patients who underwent minimally invasive thoracolumbar/sacral decompression and bullet removal at a level 1 trauma center. OBJECTIVE: To describe the use of minimally invasive techniques to achieve decompression and bullet removal for GSW to the spine. METHODS: From 2010 to 2017, 7 patients with spinal GSW underwent minimally invasive decompression and bullet removal at an academic level 1 trauma center. RESULTS: Patient ages ranged from 20 to 55 yr (mean: 31 yr). The mechanisms of injury were GSW to the abdomen/pelvis (n = 6) and direct GSW to the spine (n = 1). Based on the neurological examination, the injuries were characterized as complete (n = 1) or incomplete (n = 6). Decompression and bullet removal were performed using a tubular retractor system. All patients with incomplete injuries who had postdischarge follow-up demonstrated some neurologic recovery. There were no postoperative wound infections, cerebrospinal fluid (CSF) fistulas, or other complications related to the procedure. CONCLUSION: Minimally invasive decompression and bullet removal is a safe technique that may help reduce the risk of postoperative infections and CSF fistulas in patients with GSW to the lumbar spine compared to the standard open technique. This approach appears to be particularly beneficial in patients with incomplete injuries and neuropathic pain refractory to medical treatment.

Primary pain generator identification by CT-SPECT in patients with degenerative spinal disease.

OBJECTIVE: Axial spinal pain generators are difficult to identify using current diagnostic modalities. Merging CT with SPECT (CT-SPECT) scans allows for accurate identification of areas with increased osteoblastic activity, which may reflect pain generators. In this study, the authors aimed to evaluate the degree of pain improvement in patients who underwent surgery, addressing primary pain generators identified by CT-SPECT. METHODS: The authors retrospectively reviewed all patients with chronic axial spine pain who underwent diagnostic CT-SPECT at their institution and analyzed pain improvement in those who underwent surgical treatment in order to determine whether CT-SPECT correctly identified the primary pain generator. RESULTS: A total of 315 patients underwent diagnostic CT-SPECT between January 2014 and August 2018. Forty-eight patients underwent either cervical or lumbar fusion; there were 26 women (16 cervical, 10 lumbar) and 22 men (9 cervical, 13 lumbar). The overall axial spinal pain, as assessed through self-reporting of visual analog scale scores at 6 months postoperatively, improved from 9.04 ± 1.4 to 4.34 ± 2.3 (p = 0.026), with cervical fusion patients improving from 8.8 ± 1.8 to 3.92 ± 2.2 (p = 0.019) and lumbar fusion patients improving from 9.35 ± 0.7 to 4.87 ± 2.3 (p = 0.008). CONCLUSIONS: CT-SPECT may offer a diagnostic advantage over current imaging modalities in identifying the primary pain generator in patients with axial spinal pain.

Change in Policy Allowing Overlapping Surgery Decreases Length of Stay in an Academic, Safety-Net Hospital.

BACKGROUND: The practice of surgeons running overlapping operating rooms has recently come under scrutiny. OBJECTIVE: To examine the impact of hospital policy allowing overlapping rooms in the case of patients admitted to a tertiary care, safety-net hospital for urgent neurosurgical procedures. METHODS: The neurosurgery service at the hospital being studied transitioned from routinely allowing 1 room per day (period 1) to overlapping rooms (period 2), with the second room being staffed by the same attending surgeon. Patients undergoing neurosurgical intervention in each period were retrospectively compared. Demographics, indication, case type, complications, outcomes, and total charges were tracked. RESULTS: There were 59 urgent cases in period 1 and 63 in period 2. In the case of these patients, the length of stay was significantly decreased in period 2 (13.09 d vs 19.52; P = .006). The time from admission to surgery (wait time) was also significantly decreased in period 2 (5.12 d vs 7.00; P = .04). Total charges also trended towards less in period 2 (${\$}$150 942 vs ${\$}$200 075; P = .05). Surgical complications were no different between the groups (16.9% vs 14.3%; P = .59), but medical complications were significantly decreased in period 2 (14.3% vs 30.5%; P = .009). Significantly more patients were discharged to home in period 2 (69.8% vs 42.4%; P = .003). CONCLUSION: As a matter of policy, allowing overlapping rooms significantly reduces the length of stay in the case of a vulnerable population in need of urgent surgery at a single safety-net academic institution. This may be due to a reduction in medical complications in these patients.

A case series of penetrating spinal trauma: comparisons to blunt trauma, surgical indications, and outcomes.

OBJECTIVEWhile blunt spinal trauma accounts for the majority of spine trauma, penetrating injuries affect a substantial number of patients. The goal of this study was to examine the epidemiology of penetrating spine injuries compared with blunt injuries and review the operative interventions and outcomes in the penetrating spine injury group.METHODSThe prospectively maintained trauma database was queried for spinal fractures from 2012 to 2018. Charts from patients with penetrating spine trauma were reviewed.RESULTSA total of 1130 patients were evaluated for traumatic spinal fractures; 154 injuries (13.6%) were secondary to penetrating injuries. Patients with penetrating injuries were significantly younger (29.2 years vs 44.1 years, p < 0.001), more likely male (87.7% vs 69.2%, p < 0.001), and more commonly African American (80.5% vs 33.3%, p < 0.05). When comparing primary insurers, the penetrating group had a significantly higher percentage of patients covered by Medicaid (60.4% vs 32.6%, p < 0.05) or prison (3.9% vs 0.1%, p < 0.05) or being uninsured (17.5% vs 10.3%, p < 0.05). The penetrating group had a higher Injury Severity Score on admission (20.2 vs 15.6, p < 0.001) and longer hospital length of stay (20.1 days vs 10.3 days, p < 0.001) and were less likely to be discharged home (51.3% vs 65.1%, p < 0.05). Of the penetrating injuries, 142 (92.2%) were due to firearms. Sixty-three patients (40.9%) with penetrating injuries had a concomitant spinal cord or cauda equina injury. Of those, 44 (69.8%) had an American Spinal Injury Association Impairment Scale (AIS) grade of A. Ten patients (15.9%) improved at least 1 AIS grade, while 2 patients (3.2%) declined at least 1 AIS grade. Nine patients with penetrating injuries underwent neurosurgical intervention: 5 for spinal instability, 4 for compressive lesions with declining neurological examination results, and 2 for infectious concerns, with some patients having multiple indications. Patients undergoing neurosurgical intervention did not show a significantly greater change in AIS grade than those who did not. No patient experienced a complication directly related to neurosurgical intervention.CONCLUSIONSPenetrating spinal trauma affects a younger, more publicly funded cohort than blunt spinal trauma. These patients utilize more healthcare resources and are more severely injured. Surgery is undertaken for limiting progression of neurological deficit, stabilization, or infection control.

The increasing frequency of intravenous drug abuse-associated spinal epidural abscesses: a case series.

OBJECTIVEFew studies have been published specifically examining intravenous drug abuse (IVDA)-associated spinal epidural abscesses (SEAs), an unfortunate sequela of the opioid crisis in the United States. Here, the authors examined a series of patients with IVDA-associated SEAs in order to shed light on this challenging disease entity.METHODSThis study is a retrospective chart review of patients presenting with IVDA-associated SEAs at the authors' institution from 2013 to 2018, spanning the statewide implementation of opioid-prescribing restrictions.RESULTSA total of 45 patients presented with IVDA-associated SEAs; 46.5% presented with a neurological deficit. Thirty-one patients underwent surgery for neurological deficit, failure of medical therapy, or both. Nineteen surgical patients underwent a fusion procedure along with decompression. The complication rate was 41.9%, and the mortality rate was 6.7%. The average length of stay was 27.6 days. Patients who underwent surgery within 24 hours of onset of neurological symptoms trended toward more improvement in their American Spinal Cord Association Impairment Scale grade than those who did not (0.5 vs -0.2, p = 0.068). Methicillin-resistant Staphylococcus aureus was isolated as the causative pathogen in 57.8% of patients. Twenty-three patients (51.5%) kept their scheduled clinic follow-up appointments. Of the fusion patients with adequate follow-up, 5 showed bony arthrodesis and 3 had pseudarthrosis. The rate of IVDA-associated SEAs increased after opioid-prescribing restrictions were put in place, from 0.54 cases per month to 1.15 cases per month (p = 0.017).CONCLUSIONSPatients with IVDA-associated SEAs are challenging to treat, with high complication rates and poor follow-up. This disease is increasing in frequency, and opioid-prescribing restrictions did not slow that rise. Community outreach to promote prevention, early medical attention, and medication compliance would benefit this largely publicly funded patient population.

The Safety and Efficacy of CT-Guided, Fluoroscopy-Free Vertebroplasty in Adult Spinal Deformity Surgery.

OBJECTIVE: The goal of this study is to analyze the safety and efficacy of a novel technique of computed tomography-guided, fluoroscopy-free vertebroplasty as an adjunct to help prevent proximal junction kyphosis (PJK) in long-segment posterior spinal fusions. METHODS: We performed a retrospective analysis of 118 consecutive patients with adult spinal deformity who underwent long-segment fusion with vertebroplasty augmentation from 2013-2016 at a single institution. For each patient, we collected demographics, surgical information, length of stay, discharge disposition, and complications, including reoperation, PJK, and PJK requiring reoperation. We reviewed all postoperative radiographs to assess for cement leakage from vertebroplasty. These patients were compared to a historical control of 253 patients who underwent adult spinal deformity surgery without vertebroplasty augmentation. RESULTS: The PJK rate of 14% and the PJK requiring reoperation rate of 3% in the cohort of 118 patients who underwent vertebroplasty-augmented fusion was significantly lower than that of the 253 historical controls at our institution who did not undergo vertebroplasty (40% PJK rate, 17% PJK-rate requiring reoperation; both P < 0.001). After controlling for patient and other surgical factors in multivariate analyses, vertebroplasty was significantly associated with lower rates of PJK and PJK requiring reoperation (P < 0.001 and P = 0.003). CONCLUSIONS: Our novel vertebroplasty technique is safe, and it eliminates the need for additional fluoroscopy in cases already using the O-arm to verify screw placement. In addition, it is an effective technique for reducing PJK in adult spinal deformity surgery compared with historical institutional controls.

A modified, less invasive posterior subscapular approach to the brachial plexus: case report and technical note.

The traditional posterior subscapular approach offers excellent exposure of the lower brachial plexus and has been successfully used in patients with recurrent thoracic outlet syndrome after an anterior operation, brachial plexus tumors involving the proximal roots, and postirradiation brachial plexopathy, among others. However, this approach also carries some morbidity, mostly related to the extensive muscle dissection of the trapezius, rhomboids, and levator scapulae. In this article, the authors present the surgical technique and video illustration of a modified, less invasive posterior subscapular approach, using a small, self-retaining retractor and only a partial trapezius and rhomboid minor muscle dissection. This approach is likely to result in decreased postoperative morbidity and a shorter hospital stay.