Abstract
OBJECTIVE: Kümmell's disease (KD) represents a delayed form of osteoporotic vertebral collapse and shares clinical features with osteoporotic vertebral compression fractures (OVCF). Percutaneous kyphoplasty (PKP) is commonly performed for both conditions, yet comparative evidence and predictors of 1-year outcomes in KD remain limited. This study aimed to evaluate the efficacy and safety of PKP for the treatment of stage I and II KD and to identify factors associated with the outcomes at 1-year follow-up. METHODS: We included 387 inpatients with KD or OVCF who underwent PKP from January 2016 to December 2022. All patients were assigned to the KD group (n = 107) and the OVCF group (n = 280). The difference of demographic data (age, gender, surgical segment, osteoporosis severity and disease duration), clinical efficacy (visual analog scale and Oswestry disability index of pre-operation, 3-day post-operation, 3-month post-operation, and 1-year post-operation), complications (bone cement leakage during surgery and postoperative refractures), and radiographic parameters (anterior vertebral height and kyphotic angle of pre-operation, post-operation, and 1-year follow-up) was analyzed. Intergroup comparisons of continuous variables were performed using the Student's t-test. Repeated measures ANOVA with Bonferroni post hoc correction was used to evaluate intra-group differences of visual analog scale (VAS), Oswestry disability index (ODI), anterior vertebral height (AVH) and kyphotic angle (KA) across different time points. Multivariate logistic regression analysis was employed to identify the independent factors influencing VAS and ODI scores during the follow-up period. RESULTS: The disease duration of the KD group was much longer than that of the OVCF group. Significant improvements in VAS and ODI were observed at three-day, three-month, and one-year after PKP. Multivariate regression analysis identified the blocky cement distribution pattern, higher preoperative VAS, and higher preoperative ODI as independent risk factors for suboptimal recovery during follow-up. Besides, the KD group had lower AVH and larger KA than the OVCF group preoperatively. Both groups showed significant improvements in AVH and KA after PKP. However, the KD group had a higher rate of type II bone cement leakage (BCL) and more severe cemented vertebral collapse at the final follow-up. The mean bone cement volume was significantly greater in the KD group. Refracture rates were similar between the two groups during follow-up. CONCLUSIONS: PKP can effectively alleviate back pain, improve functional impairment, and correct local deformity in KD patients, with the risks of BCL and vertebral collapse or refractures during follow-up. It is suitable for KD treatment without nerve injury symptoms. Appropriate measures should be taken to reduce the risk of complications.