Lollipop Technique for Treatment of osteoporotic vertebral compression simultaneous with pedicle fractures

Technical Summary: The Lollipop Technique for Osteoporotic Vertebral Compression Fractures with Pedicle Fractures

Problem Statement
Osteoporotic vertebral compression fractures (OVCFs), particularly those associated with Kümmell disease (KD) and concomitant pedicle or vertebral-pedicle junction fractures, present a complex clinical challenge. While Percutaneous Kyphoplasty (PKP) is a standard minimally invasive treatment for pain relief and vertebral stabilization, it primarily addresses the anterior and middle spinal columns. In cases involving posterior column instability (pedicle fractures), conventional PKP may fail to provide sufficient biomechanical stability. This deficiency can lead to persistent pain, progressive kyphotic deformity, cement displacement, and a high incidence of adjacent vertebral fractures (AVF). Traditional open pedicle screw fixation offers stability but involves extensive soft-tissue dissection, prolonged operative time, and significant blood loss, making it less suitable for elderly patients with multiple comorbidities. There is a recognized need for a minimally invasive strategy that combines the benefits of vertebral augmentation with posterior column stabilization.

Methodology
This retrospective comparative study analyzed 54 patients with OVCFs accompanied by pedicle fractures treated between May 2023 and March 2025. Patients were divided into two groups based on the surgical technique:

1. Anchoring Group (n=26): Treated with the "Lollipop technique," a novel approach combining PKP with hollow screw anchoring.
2. Non-Anchoring Group (n=28): Treated with conventional PKP alone.

The Lollipop Technique Procedure:

• Preparation: Under fluoroscopic guidance, a small skin incision is made, and a guide needle is advanced through the pedicle into the posterior third of the vertebral body.
• Augmentation: For patients with intravertebral vacuum clefts (KD), sclerotic bone is drilled to facilitate anchorage, followed by balloon kyphoplasty to restore vertebral height.
• Cement Injection: Polymethylmethacrylate (PMMA) bone cement is injected into the vertebral body.
• Anchoring: Before the cement fully polymerizes, the delivery cannula is removed. A cannulated hollow screw (5.0–5.5 mm diameter) is inserted through the pedicle and driven through the vertebral body until the tip reaches the anterior third.
• Mechanism: The screw anchors directly into the hardened bone cement, creating a "cement-screw composite" structure. The cement acts as the "lollipop body," and the screw acts as the "stick," mechanically stabilizing the pedicle and vertebral-pedicle junction fractures without the need for connecting rods or extensive instrumentation.

Key Results

• Operative Efficiency: There was no significant difference in operative time between the two groups (52.1 ± 12.8 min vs. 49.5 ± 11.7 min, p > 0.05), indicating the anchoring procedure does not significantly prolong surgery.
• Clinical Outcomes: Both groups showed significant postoperative improvements in Visual Analog Scale (VAS) scores and Oswestry Disability Index (ODI). However, the anchoring group demonstrated significantly superior pain relief and functional recovery at 3-month and 12-month follow-ups compared to the non-anchoring group (p < 0.05).
• Radiological Stability: The anchoring group achieved better immediate restoration of anterior vertebral height and kyphotic angle correction. Crucially, the anchoring group maintained these radiological improvements significantly better over 12 months, with less loss of vertebral height and less progression of kyphosis (p < 0.05).
• Complications: The anchoring group exhibited a significantly lower rate of cement displacement (4.5% vs. 16.3%, p < 0.05) and a reduced incidence of adjacent vertebral fractures within 12 months (6.6% vs. 21.3%, p < 0.05). No screw-related complications (loosening or displacement) or severe adverse events were reported in the anchoring group.

Key Contributions and Significance
The paper claims to be the first study to evaluate the "Lollipop technique" (hollow screw–anchored bone cement augmentation) specifically for the distinct clinical entity of osteoporotic vertebral compression fractures accompanied by pedicle fractures.

• Biomechanical Innovation: The study demonstrates that anchoring bone cement with hollow screws provides superior biomechanical stability compared to conventional PKP alone. This approach addresses the posterior column instability often missed in standard augmentation, effectively treating the "three-column" instability in a minimally invasive manner.
• Clinical Efficacy: The technique offers a favorable balance of efficacy and safety, providing better long-term maintenance of vertebral height and kyphotic correction while significantly reducing the rates of cement displacement and adjacent segment fractures.
• Feasibility: The procedure is shown to be feasible without significantly increasing operative time or blood loss, making it a viable option for elderly, osteoporotic patients who might not tolerate open fixation.

Limitations
The authors acknowledge the study's limitations, including its retrospective design, potential selection bias, relatively small sample size, and a follow-up duration of only 12 months. They note that long-term outcomes regarding screw loosening or cement fatigue were not assessed and that further biomechanical testing (e.g., cadaveric models) is required to fully elucidate the optimal screw configurations.