Forearm bone mineral density predicts subsidence of titanium mesh cage after anterior cervical corpectomy and fusion in patients with cervical spondylosis.
Background: Subsidence of the titanium mesh cage (TMC) is a frequent and difficult adverse effect following anterior cervical corpectomy and fusion (ACCF). Since low bone mineral density (BMD) has also been identified as an independent risk factor for TMC, forearm BMD measurement has gained more interest recently because of its accuracy and convenience. Systematic research on the precise correlation between titanium mesh subsidence risk following ACCF surgery and forearm bone mineral density is, however, insufficient.
Methods: This study retrospectively evaluated 114 patients who were treated with ACCF at the Affiliated Hospital of North Sichuan Medical College between September 2020 and September 2023. Patients were divided into two groups according to whether the titanium mesh subsidence occurred during the follow-up period: the non-subsidence group and the subsidence group. The patient's age, sex, smoking history, body mass index, diabetes history, surgical stage,disease type, HU value of upper and lower vertebrae, forearm bone density, Restored height of fused segmental vertebrae and other basic information were obtained. Potential risk factors of TMC subsidence were screened by single factor analysis, and independent risk factors were found by Logistic regression analysis. ROC curve and area under curve (AUC) were used to assess forearm bone mineral density to predict TMC subsidence.
Results: There were 39 incidences of titanium mesh subsidence among the 114 patients who were followed for at least 12 months. Significant differences were seen between the subsidence and non-subsidence groups in the restored height of fused segmental vertebrae, forearm BMD, HU value of upper vertebral body, and HU value of lower vertebral body. After multivariate logistic regression analysis, forearm BMD (OR 0.934; 95% CI 0.895-0.973, P = 0.034) and lower vertebral body HU value (OR 0.915; 95% CI 0.857-0.963, P = 0.023) were identified as independent risk variables for titanium mesh subsidence. Each 0.1 g/cm2 increase in forearm BMD decreased the probability of titanium mesh subsidence by 6.6%. For every 1 HU rise in lower vertebral body HU value, the chance of titanium mesh subsidence decreased by 8.5%. The risk of mesh subsidence was significantly higher in patients with low forearm BMD and lower vertebral body HU value. The AUC for forearm BMD value and HU value in predicting titanium mesh subsidence were 0.858 and 0.897, respectively.
Conclusions: Forearm BMD is an independent risk factor for titanium mesh subsidence after ACCF. Forearm BMD can be a valid predictor of titanium mesh subsidence after ACCF, as can HU value of the lower vertebral body.