Study design: Retrospective cohort study. Objectives: This study evaluated the outcomes of radiation therapy (RT) as the initial treatment for Bilsky grade 2 metastatic epidural spinal cord compression (MESCC) and identified the risk factors associated with RT failure. Methods: This retrospective cohort study enrolled 151 patients diagnosed with Bilsky grade 2 MESCC. Patients were divided into 2 groups, viz. those who initially underwent RT (n = 127) and those treated with surgery at presentation (n = 24). The patient demographics, treatment outcomes, and risk factors for RT failure were analyzed. The Spinal Instability Neoplastic Score (SINS) and clinical outcomes such as ambulatory status and neurological function were compared. Logistic regression was performed to identify factors predictive of RT failure. Results: RT was successful in 85.8% (109/127) of patients, and only 14.2% (18/127) required surgery due to symptom progression. The SINS were significantly higher in the RT-failure group (9.6 ± 3.2) than in the RT-success group (7.4 ± 2.8, P = 0.003). SINS scores >8 were associated with a higher risk of RT failure. Patients the surgery group were younger and presented more frequently with neurological deficits. No significant differences in final ambulatory status or survival were observed between the RT-success and RT-failure subgroups. Conclusions: RT can be a viable initial treatment option for Bilsky grade 2 MESCC in the absence of neurological deficits or severe mechanical pain. However, patients with greater spinal instability (SINS >8) face a higher risk of RT failure and may benefit from surgical intervention at diagnosis.

Kim J, et al. J Korean Med Sci. 2021 Nov;36(47):e326. https://doi.org/10.3346/jkms.2021.36.e326

Background/Objectives: This study aimed to identify risk factors associated with mechanical failure in patients undergoing spinal instrumentation without fusion for metastatic spinal tumors. Methods: We retrospectively evaluated data from 220 patients with spinal tumors who underwent instrumentation without fusion. Propensity scores were used to match preoperative variables, resulting in the inclusion of 24 patients in the failure group (F group) and 72 in the non-failure group (non-F group). Demographic, surgical, and radiological characteristics were compared between the two groups. Logistic regression and Kaplan–Meier survival analyses were conducted to identify predictors of mechanical failure. Results: Propensity score matching resulted in a balanced distribution of covariates. Lower Hounsfield unit (HU) values at the lowest instrumented vertebra (LIV) were the only independent predictor of implant failure (p = 0.037). A cutoff value of 127.273 HUs was determined to predict mechanical failure, with a sensitivity of 59.1%, specificity of 73.4%, and area under the curve of 0.655 (95% confidence interval: 0.49–0.79). A significant difference in survival was observed between the groups with HU values above and below the cutoff (p = 0.0057). Cement-augmented screws were underutilized, with an average of only 0.2 screws per patient in the F group. Conclusions: Preoperative LIV HU values < 127.273 were strongly associated with an increased risk of mechanical failure following spinal instrumentation without fusion. Alternative surgical strategies including the use of cement-augmented screws are recommended for patients with low HU values.

Study Design: Retrospective cohort study.Purpose: To evaluate whether untreated foraminal stenosis (FS) at levels not included in anterior cervical discectomy and fusion (ACDF) impacts postoperative outcomes in patients with cervical radiculopathy and assess if residual FS increases the risk of adjacent segment disease (ASD).Overview of Literature: Level selection for ACDF for cervical radiculopathy is complex, considering variable patient anatomy and symptoms. It is unclear whether treating only potentially symptomatic levels could provide equivalent results to managing all pathologic levels.Methods: This was a retrospective cohort study of 188 patients undergoing ACDF for degenerative cervical radiculopathy between 2014 and 2020. Patients were divided into two groups: those with all symptomatic levels decompressed (No-FS group, n=162) and those with untreated FS at levels not targeted in surgery (FS group, n=26). Postoperative outcomes, including neck pain, arm pain, and Neck Disability Index (NDI), were evaluated at 3 months and 2 years. Radiographic parameters and ASD incidence were also compared between groups.Results: Both groups showed significant improvement in neck pain, arm pain, and NDI postoperatively, with no significant intergroup differences at 3 months and 2 years. C2–C7 lordosis and sagittal vertical axis showed similar improvement in both groups postoperatively. Rates of ASD and revision surgery did not differ significantly between No-FS and FS groups (5.6% vs. 7.7%, respectively; p=0.652). Logistic regression revealed no significant predictors of NDI improvement >50% among preoperative demographic or radiographic factors.Conclusions: Untreated FS at levels outside the surgical target area did not adversely affect ACDF outcomes or increase ASD risk over a 2-year follow-up. These findings suggest that ACDF can be safely limited to levels directly associated with patient symptoms without compromising clinical outcomes, potentially reducing the surgical extent and associated risks.

Study Design: Retrospective cohort study. Objectives: To determine whether preoperative cervical bone quality assessed by computed tomography Hounsfield units (CT HU) predicts pseudarthrosis, cage subsidence, or loss of cervical lordosis after anterior cervical discectomy and fusion (ACDF) and to identify perioperative predictors. Methods: Consecutive patients who underwent 1-3-level ACDF with ≥5-year follow-up were reviewed. Outcomes included neck/arm pain visual analog scale scores, Neck Disability Index, and C2-C7 lordosis and segmental height. Bone quality was assessed by preoperative CT HU. Subgroup comparisons, multivariable regression, and receiver operating characteristic (ROC) analyses evaluated predictors. Results: Among 253 patients, subsidence, pseudarthrosis, and loss of lordosis occurred in 15 (5.9%), 26 (10.3%), and 41 (16.2%), respectively. Index HU and clinical outcomes did not differ between subgroups defined by subsidence or pseudarthrosis. HU ≤ 231.5 was associated with a higher incidence of loss of lordosis. On regression, higher BMI and greater segmental lengthening independently predicted subsidence, while multilevel surgery predicted pseudarthrosis. Greater preoperative C2-C7 lordosis predicted loss of lordosis; very low HU (≤231.5) was significant in univariable analysis but not after multivariable adjustment. On ROC analysis, Index HU did not predict subsidence (AUC: 0.511), pseudarthrosis (AUC: 0.414), or loss of lordosis (AUC: 0.551). In contrast, segmental lengthening predicted subsidence (AUC 0.695) with threshold around 3 mm (3.12 mm). Conclusion: Preoperative cervical CT HU did not predict pseudarthrosis or subsidence over ≥5 years after ACDF; low HU showed an unadjusted association with loss of lordosis. Bone quality alone may be insufficient to justify avoiding ACDF. Limiting segmental lengthening to ∼3 mm may mitigate subsidence risk.