ACADEMIC FRONTIER
Osteoporotic vertebral compression fractures (OVCF) pose a serious threat to the health of the elderly population.Traditional percutaneous vertebroplasty relies heavily on the surgeon’s experience, leading to challenges such as uneven bone cement distribution, high risk of cement leakage, and significant radiation exposure during surgery.Perlove Medical has independently developed an orthopedic surgical robot that integrates intelligent 3D planning and sub-millimeter navigation technology, providing a precise solution for OVCF treatment. A recently published international SCI paper in《BMC Musculoskeletal Disorders》has validated its clinical advantages.
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Background Introduction
Paper Title：A relevant investigation of the degree of cement diffusion after robot-assisted percutaneous vertebroplasty
Authors: Yan cheng Zhu, Hai long Chen , Liang Li, Yong kang Yang , Yi shi Jia,Chang Liu , Xiao fei Xu , Jian Ruan
Corresponding Authors: Bo yao Wang, Jun Liu
Published in：BMC Musculoskeletal Disorders
BMC Musculoskeletal Disorders is a U.S.-based academic journal specializing in research on musculoskeletal system diseases. Published by BioMed Central, the journal has been committed to providing a platform for researchers, clinicians, and experts in related fields to exchange insights on the prevention, diagnosis, management, and scientific research of musculoskeletal disorders since its inception in 2000.
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Excerpt from the Paper
❐ Research Background:
Osteoporotic vertebral compression fracture (OVCF) is a prevalent disease among the elderly population, which significantly affects their quality of life and has emerged as a prominent public health issue.Percutaneous vertebroplasty(PVP) is a procedure designed to restore the structural integrity and biomechanical stability of a fractured vertebral body. It has emerged as the preferred treatment for osteoporotic vertebral compression fractures (OVCF) due to its minimally invasive nature, rapid recovery time, and ability to effectively correct kyphosis . However, the conventional method of administering bone cement under fluoroscopic guidance with a C-arm machine necessitates multiple punctures and fluoroscopic exposures, leading to increased tissue injury, radiation exposure, and potential complications such as cement leakage and persistent postoperative pain. In recent years, significant progress has been made in the use of orthopedic surgical robots, particularly in robot-assisted pedicle screw placement, where accuracy has significantly improved compared to non-robotic methods. However, there is still limited literature on the application of orthopedic surgical robots in percutaneous vertebroplasty (PVP).
❐ Sample Study：This research analyzed OVCF patients who received PVP treatment at the Second Affiliated Hospital of Nanjing Medical University from January 2023 to November 2023. The study included 96 patients with OVCF, with 48 undergoing PVP and 48 undergoing robot-assisted PVP. Informed consent was obtained from each patient for the use and analysis of clinical data.
❐ Robot-assisted operation:（Perlove Medical）The spinal surgery robot(PL300B) is equipped with a 3D C-arm, an optical tracking system trolley, a mechanical arm trolley, and a variety of supporting surgical and positioning tools(Fig.1A). Prior to the surgical procedure, the patient’s pertinent information was recorded, and the orientation information for the 3D image was deter- mined based on the patient’s positioning and the movement of the C-arm.During the surgical procedure, a tracer holder and an optical locator were used to identify the tracking spheres of the orthopedic localizer. After positioning the device and acquiring a 3D image, the image was sent from the 3D C-arm workstation to the optical tracking system trolley(Fig.1B).
The robot arm was positioned at the designated point in accordance with a pre-established trajectory, the operator initiates the execution phase by foot-operated input, moving the robotic arm to travel to the planned location and confirming that the accuracy of the on-screen display meets the requirements (Fig.1.C and D). Using a long-handled sharp knife, the operator cut open the skin in the direction of the guide, inserts the sleeve, and drives in the puncture needle with an electric drill, guided by the sleeve. The process is repeated for the contralateral puncture needle (Fig.1E). The working sleeve is then placed according to the K-wire puncture path and bone cement is injected(Fig.1F).
❐ Data collection：Baseline characteristics of OVCF patients including age, sex, BMD T-value and vertebral fracture segment were collected. The degree of cement diffusion was determined from preoperative, postoperative, and 3-month postoperative follow-up lumbar frontal and lateral views. During the procedure, we recorded the number of fluoroscopes used, the total radiation dose, and whether there was any cement leakage. We used the Visual Analogue Scale (VAS) to evaluate the patient’s pain after the vertebral fracture, and the Oswestry Disability Index (ODI) to assess their recovery and rehabilitation. The preoperative, 3-day postoperative, and 3-month postoperative VAS and ODI scores were recorded. The angle of abduction perforation was measured and recorded based on the cross-section of the patient’s fractured vertebrae onthe postoperative follow-up CT scan.
❐ Statistical analysis：Analysis was conducted using SPSS version 27.0 statistical software. Normality tests were performed on measurement data, which were found to conform to a normal distribution.Mean±SD was used to express the data, and independent samples t-tests were used to compare groups.Univariate and multivariate logistic regression analyses were conducted to assess the factors influencing postoperative bone cement distribution. Patients’ clinical characteristics were used as independent variables and postoperative bone cement distribution grade as the dependent variable. The statistical difference was significant at P<0.05.
❐ Demographic and clinical characteristics of patients with OVCF
The PVP group consisted of 34 females and 14 males with an average age of (70.79±7.91) years, while the R-PVP group consisted of 36 females and 12 males with an average age of (70.96±7.87) years.There were no statistically significant differences between the two groups in terms of age and gender. The T-value of each patient’s bone density was assessed, and no significant difference was found between the two Groups. There was no statistically significant difference in the distribution of fractured vertebrae between the two groups.
① According to the cross-sectional measurements of the puncture abduction angle from postoperative follow-up CT scans, there was a significant difference between the two groups (P<0.05).
②The amount of bone cement injected was (6.135+1.818) ml in the PVP group and (7.563+1.420) ml in the R-PVP group, with a statistically significant difference between the two groups.
③Intra operative fluoroscopy was used less frequently in the R-PVP group compared to the PVP group with a meaningful statistical difference between the two groups.
④The degree of cement diffusion between the two groups：The extent of diffusion of the bone cement was evaluated using the Image J, and the outcomes were classified into four categories: Degree I represents a bone cement coverage of less than 50% on both orthopantomograms and lateral radiographs. Degree II represents the proportion of the area occupied by bone cement on the orthopantomograph or lateral radiographs, one of which is more than 50%, but less than 75%. Degree III classification is defined as the proportion of area occupied by bone cement exceeding 50% but less than 75% on both orthopantomograms and lateral radiographs. The proportion of the area occupied by bone cement in both orthopantomograms and lateral radiographs is more than 75%, which represents Degree IV.The difference between the two groups was statistically significant.
Diffusion degree of bone cement. Postoperative X-rays show diffusion of bone cement. In comparison to the PVP group, the R-PVP group demonstrated a greater ability to converge at the vertebral midline on postoperative X-rays.
❐ Postoperative VAS and ODI scores were used to evaluate the clinical effect
To evaluate the clinical outcomes of the patient’s postoperative recovery, VAS and ODI scores were used.The scores were performed preoperatively, 3 days post operatively, and 3 months postoperatively.The postoperative VAS and ODI scores were significantly lower thanthe preoperative scores (both P<0.05). Additionally, the VAS and ODI scores at 3 months postoperatively were lower than both the preoperative and 3-day postoperative scores (P<0.05). The VAS score and ODI score of the R-pvp group were lower than those of the PVP group at3 days after surgery, with statistical significance(P<0.05).
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CONCLUSION
Overall, the application of robotic-assisted percutaneous vertebroplasty resulted in a more uniform distribution of bone cement within the vertebral body, while achievinga higher midline confluence rate. Postoperative review of X-rays and CT scans revealed a lower incidence of cement spillage and better clinical improvement in both VAS and ODI scores during postoperative follow-up.
