Objective: Percutaneous vertebroplasty (PVP) is currently the most common surgical procedure for unstable Kummell disease (KD), but bone cement loosening or displacement often occurs after the operation. 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 the safety, advantages and disadvantages of these 2 novel surgical procedures through a 2-year follow-up evaluation.
Methods: In accordance with the inclusion and exclusion criteria, from May 2017 to May 2021, 77 patients with single segmental unstable KD who had received the PVP-PPP combined therapy were included in the PPP group, and 42 patients with the same who had received the PVP-bone cement bridging screw system combined therapy were included in the screw group. All patients received the operation through unilateral approach. The changes in the vertebral body index (VBI), bisegmental Cobb angle, visual analogue scale (VAS) and Oswestry Disability Index (ODI) and the bone cement loosening rate and displacement rate at different follow-up time points were used to evaluate the clinical efficacy.
Results: The average operation duration of the PPP group was 85.52±10.78 minutes (range, 70-115 minutes), and its average bone cement injection volume was 4.98±0.67 mL (range, 4-6 mL). The average operation duration of the screw group was 52.07±9.90 minutes (range, 36-65 minutes), and its average bone cement injection volume was 4.43±0.89 mL (range, 2.5-6 mL). Before operation, immediately after operation and at 6 months after operation, there was no significant difference in VBI or bisegmental Cobb angle between the screw group and the PPP group (p>0.05), while at 1-year and 2-year midterm 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 months after operation and at 1 year after operation, there was no significant difference in VAS or ODI score between the screw group and the PPP group (p>0.05), while at 2 years after operation, 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.