A Comparative Study of 2 Techniques to Avoid Bone Cement Loosening and Displacement After Percutaneous Vertebroplasty Treating Unstable Kummell Disease

Abstract

Objective: Percutaneous vertebroplasty (PVP) is currently the most common surgical procedure for unstable Kummell disease (KD), but cement loosening or displacement often occurs after PVP. We had been using percutaneous pediculoplasty (PPP) or a self-developed bone cement bridging screw system to avoid this severe complication. This study intends to compare these novel surgical procedures through a 2-year follow-up evaluation.

Methods: From May 2017 to May 2021, 77 patients with single-level unstable KD were included in the PPP group, and 42 patients received the PVP-bone cement bridging screw system were included in the screw group. The changes in the vertebral body index (VBI), bisegmental Cobb angle, visual analogue scale (VAS) and Oswestry Disability Index (ODI) and the cement loosening rate and displacement rate at different follow-up time points were used to evaluate the clinical efficacy.

Results: There was no significant difference in VBI or bisegmental Cobb angle between the 2 groups (p > 0.05) before operation, immediately after operation and at 6-month followup, while at 1-year and 2-year postoperative evaluations, the screw group had higher VBI and bisegmental Cobb angle than the PPP group (p < 0.05). Before operation, immediately after operation, at 6-month and 1-year follow-up, there was no significant difference in VAS or ODI score between the 2 groups (p > 0.05), while at 2-year follow-up, the screw group still had higher VAS and ODI scores than the PPP group (p < 0.05). No bone cement displacement occurred in both groups, but the rate of bone cement loosening was 14.29% in group PPP, and 0 in screw group (p < 0.05).

Conclusion: This 2-year follow-up study shows that the PVP-bone cement bridging screw system combined therapy had better midterm treatment efficacy than the PVP-PPP combined therapy in patients with unstable KD, and the bone cement bridging screw system is a preferred therapy with better anti cement loosening ability.

Keywords: Bone cement bridging screw; Bone cement loosening; Kummell disease; Pediculoplasty; Vertebroplasty.

Fig. 1.

Pediculoplasty combined with vertebroplasty and bone cement bridging screw system combined with vertebroplasty to treat Kummell disease surgical operation diagram. (A) Kummell disease causes vertebral body collapse and kyphosis. (B) After the collapsed vertebral body is reset and the spine hyperextension is corrected, the anterior edge of the vertebral body has a bone defect. (C) Use bone cement to fill the bone defect and the pedicle to complete the pediculoplasty combined with vertebroplasty treatment. (D) Sagittal view after pediculoplasty combined with vertebroplasty. (E) Schematic diagram of the postoperative axial position after pediculoplasty combined with vertebroplasty. (F) The vertebroplasty treatment is completed by the minimally invasive implantation of a bone cement bridging screw. (G) Sagittal view of the bone cement bridging screw system combined with vertebroplasty. (H) Schematic diagram of the postoperative axial position of the bone cement bridging screw system combined with vertebroplasty.

Fig. 2.

Postoperative x-ray data of 2 typical patients. (A) Pediculoplasty combined with vertebroplasty treatment. (B) Unilateral novel bone cement bridging screw combined with vertebroplasty treatment. Postoperative computed tomography data of 2 typical patients. (C) Pediculoplasty combined with vertebroplasty treatment. (D) Unilateral novel bone cement bridging screw combined with vertebroplasty treatment.

Fig. 3.

Schematic diagram of imaging parameter measurement. The measurement methods of bisegmental Cobb angle is shown in the figure, and the measurement method of vertebral body index is (a/b)×100%.

Fig. 4.

Comparison of preoperative and postoperative vertebral body index (VBI) between percutaneous pediculoplasty (PPP) group and screw group at different time points. p < 0.05, VBI of patients in PPP group compared with screw group.

Fig. 5.

Comparison of preoperative and postoperative bisegmental Cobb angle between percutaneous pediculoplasty (PPP) group and screw group at different time points. p < 0.05, bisegmental Cobb angle of patients in PPP group compared with screw group.

Fig. 6.

Comparison of preoperative and postoperative visual analogue scale (VAS) score between percutaneous pediculoplasty (PPP) group and screw group at different time points. p < 0.05, VAS score of patients in PPP group compared with screw group.

Fig. 7.

Comparison of preoperative and postoperative Oswestry Disability Index (ODI) score between percutaneous pediculoplasty (PPP) group and screw group at different time points. p < 0.05, ODI score of patients in PPP group compared with screw group.