Eugene Y. Koh

Background/Objectives: Poor bone quality compromises pedicle screw fixation, and cement augmentation of fenestrated screws improves fixation at the screw–bone interface. Whether low interface-failure rates translate into low all-cause reoperation rates in routine practice is not established. We characterized the institutional use of cement-augmented fenestrated pedicle screws, the retrospectively measured vertebral computed tomography (CT) attenuation of selected patients, and subsequent interface failure and reoperation. Methods: We reviewed all patients undergoing thoracolumbar pedicle screw fixation between January 2016 and June 2022 at one tertiary referral center. Vertebral attenuation was measured retrospectively in Hounsfield units (HU) at L1 through L4. Outcome proportions are reported with Wilson 95% confidence intervals. Comparisons across surgical indications used exact tests with Holm correction and were treated as exploratory. Cement leakage and other cement-specific safety events could not be ascertained and were not study outcomes. Results: Cement augmentation was used in 101 of 2285 screened patients (4.4%), and 68 met the criteria for the outcome cohort (median follow-up, 44.9 weeks). Median attenuation was 94 HU, and 35 of 53 measurable patients (66.0%) fell below 110 HU, whereas formal densitometry was documented in 3. Screw loosening and pullout each occurred in three patients (4.4%), and reoperation for any cause occurred in nine (13.2%). Reoperation was more frequent among deformity constructs (30.4%) than for trauma (6.1%) or oncologic disease (0%); omnibus exact p = 0.016, although this result did not remain significant after Holm correction (adjusted p = 0.10). Conclusions: Cement augmentation was applied selectively, and retrospective CT measurements identified low vertebral attenuation in most measurable patients, despite infrequent formal densitometry. Failure at the screw–bone interface was infrequent, whereas all-cause reoperation remained clinically relevant and varied by surgical context. This study describes the selection and outcomes after augmentation but cannot establish comparative effectiveness or the safety of the augmentation technique.

Background/Objectives: Lumbar fusion for degenerative pathology is increasingly common, yet revision surgery, often due to adjacent segment disease, remains a major concern. While sagittal alignment has been widely studied, the role of preoperative lumbar retrolisthesis is less clear. This study evaluated the prevalence, distribution, and clinical significance of preoperative retrolisthesis in patients undergoing single-level L4–L5 fusion, with a focus on its association with revision surgery. Materials and Methods: A retrospective cohort study of 116 adult patients undergoing single-level L4–L5 posterior fusion with multilevel decompression from 2018 to 2022 was performed. Retrolisthesis was defined as posterior translation ≥ 2 mm and assessed across lumbar levels. Patients were stratified by revision status. Statistical comparisons and Cox proportional hazards models were used to evaluate associations between retrolisthesis burden, radiographic parameters, and revision risk. Results: Preoperative retrolisthesis was present in 78.4% of patients, most commonly at L3–L4 and L2–L3, and frequently involved multiple levels. Presence of retrolisthesis alone was not associated with revision (85.7% vs. 77.5%, p = 0.73). However, patients with ≥3 retrolisthesis levels demonstrated reduced revision-free survival, with a higher hazard of revision on univariate analysis (HR 3.65, p = 0.055). In multivariate analysis, ≥3 levels (HR 5.50, p = 0.018) and greater absolute L4–S1 lordosis change (HR 1.09 per degree, p = 0.031) were independent predictors of revision. Conclusions: Retrolisthesis is highly prevalent in patients undergoing L4–L5 fusion but is not predictive of revision when considered alone. A greater multilevel retrolisthesis burden, particularly when combined with larger segmental lordosis change, may represent a mechanically vulnerable spine phenotype associated with increased revision risk. These findings should be interpreted as exploratory and require validation in larger cohorts.

Background/Objectives: Posterior C1–C2 fusion is commonly used for unstable traumatic odontoid injuries, but it is less commonly used for patients who initially undergo nonoperative management and later require salvage fusion. This study compared hospital length of stay, short-term complications, and postoperative radiographic alignment between salvage posterior C1–C2 fusion after failed nonoperative management and primary posterior C1–C2 fusion. Materials and Methods: A retrospective cohort study was performed of 106 adult patients who underwent posterior C1–C2 instrumented fusion for traumatic cervical spine injuries from 2011 to 2023. Patients were stratified into the salvage fusion group after radiographic nonunion following attempted nonoperative management with external immobilization or the primary fusion group, who underwent initial surgical management. The primary outcome was hospital length of stay. Secondary outcomes included postoperative radiographic alignment, screw loosening, hardware failure, revision surgery, and 30-day emergency department visits. Propensity score matching and full-cohort augmented inverse probability weighting were used to account for baseline differences between groups. Results: Twenty-seven patients underwent salvage fusion and 79 underwent primary fusion. Propensity score matching produced 25 matched pairs. In the matched cohort, salvage fusion was associated with significantly shorter length of stay than primary fusion, with a median of 2 versus 5 days, respectively (p < 0.001). This remained significant in the full-cohort augmented inverse probability weighting analysis, where salvage fusion was associated with a 2.41-day reduction in length of stay (95% CI, −3.63 to −1.19; p < 0.001). Short-term complications were uncommon in both groups, and no clear sign of increased screw loosening, hardware failure, revision surgery, or 30-day emergency department visits was observed in the salvage cohort. Salvage fusion was also associated with lower postoperative C2–C7 lordosis and a greater C1 lamina–occiput distance. Conclusions: Salvage posterior C1–C2 fusion for radiographic nonunion after attempted nonoperative management was not associated with higher short-term complication rates compared with primary fusion. While surgical-admission length of stay was shorter in the salvage cohort, this difference should be interpreted cautiously because salvage and primary fusion occur in different admission contexts and do not reflect the total episode-of-care burden. Early postoperative alignment differences were observed, but these were not correlated with clinical outcomes or longitudinal imaging, and their long-term significance remains unclear. Future multicenter studies should evaluate total healthcare utilization, fusion status, longitudinal alignment, and patient-reported outcomes after salvage C1–C2 fusion.

Background/Objectives: Postoperative cervical spine radiographs are routinely obtained during in-hospital and follow-up period. We aim to evaluate the utility of postoperative radiographs for identifying instrumentation failure and the subsequent need for revision surgery in patients with traumatic cervical spine injuries. Materials and Methods: A retrospective chart review of patients who had surgical treatment for traumatic cervical spine injury was conducted. Clinical notes and radiographic reports were evaluated. Postoperative radiographs were obtained prior to discharge from the hospital, and subsequently at 2, 6, 12, 24 weeks, and 1 year. Patients who underwent revision surgery, described as any reoperation, were identified. The patients’ indications for surgery were evaluated. The results of postoperative radiographs that prompted a change in management and reoperation were analyzed. Sensitivity and specificity for postoperative radiographs were calculated. Results: A total of 295 patients were reviewed. The rate of revision surgery was 3.7% (n = 11). All 11 patients presented changes in clinical findings and physical exam, but only 3 patients (1%) were identified to have undergone revision surgery due to instrumentation failure seen on radiographs at 13, 89, and 112 days postoperatively, and none within the inpatient period. Two patients underwent revision surgery due to epidural hematoma, and six patients due to wound infection. The overall sensitivity and specificity of routine postoperative radiographs were 27% and 100%, respectively. Conclusions: Postoperative radiographs after cervical spine trauma have low clinical utility for predicting instrumentation failure in the absence of clinical findings, particularly in the inpatient period.

Background/Objectives: Patient-reported outcome measures (PROMs) are widely used tools in orthopedic surgery for evaluating clinical outcomes, guiding research, and supporting value-based care. However, the optimal timing for collecting baseline PROMs, whether in clinic prior to surgery or on the day of surgery, remains uncertain. This study investigated whether the clinical setting (preoperative clinic vs. day of surgery) affects baseline PROMs in patients undergoing anterior cervical discectomy and fusion (ACDF). Methods: Patients undergoing elective, primary ACDF at a single institution between August 2019 and June 2021 were prospectively enrolled. Inclusion criteria included age over 18, English literacy, and eligibility for primary ACDF. Participants completed PROMIS domains, Neck Disability Index (NDI), Modified Japanese Orthopaedic Association (mJOA) score, and Visual Analog Scale (VAS) at two time points: during the preoperative clinic visit and again in the perioperative area on the day of surgery. A subgroup analysis was performed for patients with anxiety, defined as a PROMIS anxiety score ≥ 59.4. Results: A total of 63 patients were enrolled, with 48 completing both sets of surveys. The average time between the two assessments was 7.9 days (95% CI: 6.4–9.3). After Bonferroni correction (α = 0.005), no significant differences were observed in any PROMs across the two time points, including PROMIS physical function (p = 0.398), pain interference (p = 0.682), fatigue (p = 0.019), social satisfaction (p = 0.331), anxiety (p = 0.047), depression (p = 0.042), NDI (p = 0.072), mJOA (p = 0.566), VAS neck pain (p = 0.054), or VAS overall pain (p = 0.335). Subgroup analysis of anxious patients similarly revealed no statistically significant changes between settings. Conclusions: PROM scores were not meaningfully different between the preoperative clinic and the day of surgery in patients undergoing ACDF. These results are most applicable when baseline PROMs are collected within about one week of ACDF. These findings support flexibility in workflow design for PROM collection, as the timing and setting do not significantly impact baseline responses.

Background/Objectives: Cutibacterium acnes (C. acnes), formerly known as Propionibacterium acnes (P. acnes), is an anaerobic, low-virulent bacterium that has been associated with postoperative infections of the shoulder, knee, and cervical spine. Recent studies have highlighted an association between C. acnes and the development of degenerative disc disease (DDD). The aim of this study is to ascertain whether C. acnes increases the risk of subsidence following anterior cervical discectomy and fusion (ACDF). Methods: After IRB approval, consecutive patients undergoing elective ACDF for DDD from 2017 to 2018 were enrolled in this prospective cohort study. Intervertebral disc samples were taken at each affected level and cultured. A total of 66 patients with radiographic follow-ups were included in the final analysis. The extent of subsidence and cervical lordosis was determined immediately postoperatively and at the 3- and 6-month follow-ups. Results: No significant difference in subsidence was observed at 3 months (p = 0.07) or 6 months (p = 0.11) between culture-positive and -negative cohorts. Additionally, there was no significant difference detected in the change in cervical lordosis observed at 3 months (p = 0.16) or 6 months (p = 0.27) between culture-positive and -negative cohorts. For the most inferiorly fused segment, there was a significant difference in subsidence observed at 3 months (1.5 mm, 95% CI: 0.2–2.7 mm, p = 0.02) but not at 6 months (p = 0.17). Conclusions: Intervertebral discs with a positive C. acnes culture were not associated with greater levels of subsidence at 3 or 6 months following ACDF for DDD. Further research is necessary to endorse these results and to gauge the clinical significance of C. acnes infection.

Background/Objectives: A superinfection occurs when a new, secondary organism colonizes an existing infection. Spine infections are associated with high patient morbidity and sometimes require multiple irrigations and debridements (I&Ds). When multiple I&Ds are required, the risk of complications increases. The purpose of this study was to report our experience with spine superinfections and determine which patients are typically affected. Methods: A retrospective case series of spine superinfections and a retrospective case–control analysis were conducted. Data were collected manually from electronic medical records. Spine I&Ds were identified. Groups were created for patients who had multiple I&Ds for (1) a recurrence of the same causative organism or (2) a superinfection with a novel organism. Preoperative demographic, clinical, and microbiologic data were compared between these two outcomes. A case series of superinfections with descriptive data was constructed. Lastly, two illustrative cases were provided in a narrative format. Results: A total of 92 patients were included in this analysis. Superinfections occurred after 6 out of the 92 (7%) initial I&Ds and were responsible for 6 out of the 24 (25%) repeat I&Ds. The preoperative erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) of the patients with a superinfection were significantly lower than those in the control group (p = 0.022 and p = 0.032). Otherwise, the observed differences in the preoperative variables were not statistically different. In the six cases of superinfection, the presence of high-risk comorbidities, a history of substance abuse, or a lack of social support were commonly observed. The superinfecting organisms included Candida, Pseudomonas, Serratia, Klebsiella, Enterobacter, and Staphylococcus species. Conclusions: Superinfections are a devastating complication requiring reoperation after initial spine I&D. Awareness of the possibility of superinfection and common patient archetypes can be helpful for clinicians and care teams. Future work is needed to examine how to identify, help predict, and prevent spine superinfections.