[Effectiveness of TiRobot-assisted and free-hand percutaneous kyphoplasty via pedicle of vertebra in treatment of osteoporotic vertebral compression fracture of thoracic vertebra].

Objective: To compare the effectiveness of TiRobot-assisted and C-arm X-ray fluoroscopy assisted percutaneous kyphoplasty (PKP) via pedicle of vertebra in the treatment of osteoporotic vertebral compression fracture (OVCF) of thoracic vertebrae.

Methods: The clinical data of 85 patients with OVCF of thoracic vertebrae who were admitted between January 2020 and March 2023 and met the selection criteria was retrospectively analyzed including 40 patients (50 vertebrae) undergoing PKP assisted by TiRobot (group A) and 45 patients (50 vertebrae) undergoing PKP assisted by C-arm X-ray fluoroscopy (group B). There was no significant difference in the comparison of baseline data such as gender, age, body mass index, bone mineral density T-value, fracture segment, trauma history, and preoperative numerical rating scale (NRS) score, Oswestry disability index (ODI), and Cobb angle of injured vertebra between the two groups ( >0.05). The effectiveness evaluation indexes of the two groups, including the operation time, the volume of injected cement, the times of fluoroscopies, the length of hospital stay, and the occurrence of postoperative complications were collected and compared. Anteroposterior and lateral X-ray films and CT of the injured vertebra were reviewed at 1 day after operation to observe whether there was cement leakage and to evaluate the distribution of cement in the injured vertebra. Before and after operation, pain was assessed using the NRS score, dysfunction was assessed using the ODI, and vertebral height recovery was assessed by measuring the Cobb angle of the injured vertebrae by X-ray films.

Results: Both groups of patients successfully completed the operation, the operation time, the volume of injected cement, the times of fluoroscopies, and the length of hospital stay in group A were significantly less than those in group B ( <0.05). The patients in two groups were followed up 4-12 months (mean, 9.6 months). Bone cement leakage occurred in 5 vertebrae in group A and 15 vertebrae in group B after operation, all of which leaked to the intervertebral space and around the vertebral body, and the patients had no obvious clinical symptoms. The difference of bone cement leakage between the two groups was significant ( <0.05). No severe complication such as intraspinal leakage, infection, or vascular embolism was found in the two groups. At 1 day after operation, the distribution index of bone cement in group A was mostly grade Ⅴ, which was well dispersed; while in group B, it was mostly grade Ⅱ and grade Ⅴ; the difference of bone cement distribution index between the two groups was significant ( <0.05). The NRS score, ODI, and Cobb angle of injured vertebra in both groups were significantly improved at 1 day after operation when compared with preoperative ones ( <0.05). There was no significant difference in the difference of the above indexes between the two groups before and after operation ( >0.05).

Conclusion: TiRobot-assisted unilateral PKP in the treatment of OVCF of thoracic vertebrae is safe and effective, which can reduce the X-ray transmission times during operation, shorten the operation time, reduce the volume of bone cement injection, and thus decrease incidence of bone cement leakage.