STUDY DESIGN: Retrospective case series. OBJECTIVE: To characterize failure rates of cervical cages based on manufacturer and design characteristics using the nationwide database of reported malfunctions. BACKGROUND: The Food and Drug Administration (FDA) aims to ensure the safety and efficacy of cervical interbody implants postimplantation; however, intraoperative malfunctions may be overlooked. MATERIALS AND METHODS: The FDA's Manufacturer and User Facility Device Experience database was queried for reports of cervical cage device malfunctions from 2012 to 2021. Each report was categorized based on the failure type, implant design, and manufacturer. Two market analyses were performed. First, "failure-to-market share indices" were generated by dividing the number of failures per year for each implant material by its yearly US market share in cervical spine fusion. Second, "failure-to-revenue indices" were calculated by dividing the total number of failures per year for each manufacturer by their approximate yearly revenue from spinal implants in the US. Outlier analysis was performed to generate a threshold value above which failure rates were defined as greater than the normal index. RESULTS: In total, 1336 entries were identified, and 1225 met the inclusion criteria. Of these, 354 (28.9%) were cage breakages, 54 (4.4%) were cage migrations, 321 (26.2%) were instrumentation-related failures, 301 (24.6%) were assembly failures, and 195 (15.9%) were screw failures. Poly-ether-ether-ketone implants had higher failure by market share indices for both migration and breakage compared with titanium. Upon manufacturer market analysis, Seaspine, Zimmer-Biomet, K2M, and LDR exceeded the failure threshold. CONCLUSION: The most common cause of implant malfunction was breakage. Poly-ether-ether-ketone cages were more likely to break and migrate compared with titanium ones. Many of these implant failures occurred intraoperatively during instrumentation, which underscores the need for FDA evaluation of these implants and their accompanying instrumentation under the appropriate loading conditions before commercial approval.
Spinal Fusion , Titanium , United States , Humans , United States Food and Drug Administration , Retrospective Studies , Ketones , Ethers
Purpose: Lumbar interlaminar decompression with interspinous fixation is an established safe and effective treatment for spinal stenosis. Early maintenance of improvements in pain intensity and function are critical for durability of symptom relief. The purpose of this study was to investigate the efficacy of minimally invasive treatments for low back pain during the early period after treatment and their utility in setting the course for longer term success. Patients and Methods: This study utilized patient evaluations at 3- and 6-months following treatment and is part of an actively enrolling, institutional review board (IRB) approved, single-arm, multicenter, prospective, open-label 12-month study. Clinical efficacy was assessed primarily using the change from baseline in Oswestry Disability Index (ODI), Visual Analog Scale (VAS) of the back and leg pain during walking and standing, and Zurich Claudication Questionnaire (ZCQ), and secondarily using the Patient Global Impression of Change (PGIC) and Patient-Reported Outcomes Measurement Information System (PROMIS) 29 v2.1. The safety endpoints were the adverse events and reoperations or revisions at the index level(s). Results: At 6-month post-op, 76%, 62%-64%, and 64% of patients demonstrated clinical meaningful, and statistically significant improvement in their pain as defined by ZCQ, VAS (back and leg), and ODI, respectively. In addition, 78% of patients noted improvement in PGIC. Two procedure-related adverse events were noted which fully resolved without surgical intervention. Conclusion: This 6-month interim analysis at 42% enrollment of patients was conducted to determine prolonged safety and efficacy of the interspinous fusion device. Our analysis showed a sustained improvement in clinical efficacy, and safety endpoints, when compared to the 3-months evaluations, across both interventional pain and neurosurgery specialties.
INTRODUCTION: Pedicle screw loosening is a significant complication of posterior spinal fixation, particularly among osteoporotic patients and in deformity constructs. In orthopedic trauma surgery, locking plates and screws have revolutionized the fixation of osteoporotic fractures. We have combined the traumatology principle of fixed-angle locking plate fixation with the spine principles of segmental instrumentation. METHODS: A novel spinolaminar locking plate was designed based on morphometric studies of human thoracolumbar vertebrae. The plates were fixed to cadaveric human lumbar spines and connected to form 1-level L1-L2 or L4-L5 constructs and compared to similar pedicle screw constructs. Pure moment testing was performed to assess range of motion before and after 30,000 cycles of cyclic fatigue. Post-fatigue fixture pullout strength was assessed by applying a continuous axial tensile force oriented to the principal axis of the pedicle until pullout was observed. RESULTS: Spinolaminar plate fixation resulted in superior pullout strength compared to pedicle screws (1,065 ± 400N vs. 714 ± 284N, p = 0.028). Spinolaminar plates performed equivalently to pedicle screws in range of motion reduction during flexion/extension and axial rotation. Pedicle screws outperformed the spinolaminar plates in lateral bending. Finally, no spinolaminar constructs failed during cyclic fatigue testing, whereas one pedicle screw construct did. CONCLUSIONS: The spinolaminar locking plate maintained adequate fixation post-fatigue, particularly in flexion/extension and axial rotation compared to pedicle screws. Moreover, spinolaminar plates were superior to pedicle screw fixation with respect to cyclic fatiguing and pullout strength. The spinolaminar plates offer a viable option for posterior lumbar instrumentation in the adult spine.
BACKGROUND: Posterior and lateral techniques have been described as approaches to sacroiliac joint arthrodesis. The purpose of this study was to compare the stabilizing effects of a novel posterior stabilization implant and technique to a previously published lateral approach in a cadaveric multidirectional bending model. We hypothesized that both approaches would have an equivalent stabilizing effect in flexion-extension and that the posterior approach would exhibit better performance in lateral bending and axial rotation. We further hypothesized that unilateral and bilateral posterior fixation would stabilize both the primary and secondary joints. METHODS: Ranges of motion (RoMs) of six cadaveric sacroiliac joints were evaluated by an optical tracking system, in a multidirectional flexibility pure moment model, between ± 7.5 N-m applied moment in flexion-extension, lateral bending, and axial rotation under intact, unilateral fixation, and bilateral fixation conditions. RESULTS: Intact RoMs were equivalent between both samples. For the posterior intra-articular technique, unilateral fixation reduced the RoMs of both primary and secondary joints in all loading planes (flexion-extension RoM by 45%, lateral bending RoM by 47%, and axial RoM by 33%), and bilateral fixation maintained this stabilizing effect in both joints (flexion-extension at 48%, lateral bending at 53%, and axial rotation at 42%). For the lateral trans-articular technique, only bilateral fixation reduced mean RoM of both primary and secondary sacroiliac joints, and only under flexion-extension loads (60%). CONCLUSION: During flexion-extension, the posterior approach is equivalent to the lateral approach, while producing superior stabilization during lateral bend and axial rotation.
Sacroiliac Joint , Spinal Fusion , Humans , Sacroiliac Joint/surgery , Spinal Fusion/methods , Bone Screws , Biomechanical Phenomena , Lumbar Vertebrae/surgery , Range of Motion, Articular , Cadaver
Introduction: Knowing the risk factors for poor outcomes following hip fracture surgery is necessary for appropriate patient care. The objective of this study was to determine if the first post-operative visit (POV) following hip fracture surgery is a risk factor for increased mortality, complications, and re-admissions. Methods: This was a retrospective review of 285 patients who underwent operative fixation of a hip fracture at an academic acute care hospital. Outcome measurements were 90-day and one year mortality, 90-day complications, and 90-day re-admission rates in patients who missed or attended their first post-operative visit following hip fracture surgery. Results: 279 patients met inclusion criteria and had sufficient data for analysis, of which 213 (76.3%) made their first post-operative visit. 90-day and one-year mortality were significantly higher in the patients who missed their first POV (31.8% vs. 4.2%; 51.5% vs. 12.7%). Independent risk factors for 90-day complications were missing the first POV, coronary artery disease, and lower pre-injury status (ORs = 10.65, 2.80, 7.89, respectively). Independent risk factors for 90-day re-admission were missing the first POV, chronic obstructive pulmonary disease on home oxygen, and lower re-injury status (ORs = 8.04, 5.44, 5.47, respectively). Conclusion: Missing the first POV was the strongest independent risk factor for 90-day complications and 90-day readmission. Patients who miss their first POV have significantly higher 90-day and one year mortality rates.
