Effectiveness of ZOL as a First-line Therapeutic Strategy After Percutaneous Kyphoplasty

21 Mar, 22

Introduction

Zoledronic acid (ZOL) is a 3rd generation nitrogen-containing bisphosphonate.

To determine the efficacy of annual zoledronic acid (ZOL) administration against previously treated recompression vertebral fractures (RVF) and new vertebral fractures (NVF) in initial percutaneous kyphoplasty (PKP) patients with osteoporotic vertebral compression fractures (OVCF) over a 3-year follow-up period.

Patient Profile

Primary OVCF in the thoracolumbar or lumbar area within 2 weeks at the single level
MRI showing T1 hypointense signals and T2 hyperintense signals
Patients with lower back pain, local spinous process tenderness, and/or corresponding vertebral body pain with percussion

Methods

Placebo-controlled, double-blind prospective trial
154 Patients were randomly assigned to receive a
- 78 patients were assigned single infusion of ZOL (5 mg) at 1 week, 12 and 24 months postoperatively.
- 76 patients were assigned placebo (78 ZOL vs. 76 placebo) at 1 week, 12 months, and 24 months after surgery

Patients were followed-up for 36 months
Patients were assessed for radiographic assessments, VAS and ODI scores, BMD and bone turnover markers, safety measurements

Results

ZOL treatment lowered the risk of RVF by ~ 65% over the 36-month period when compared to placebo controls

Figure 1: Incidence of RVF in ZOl group vs placebo group

ZOL also reduced the risk of NVF by ~ 73%

Figure 2: Incidence of NVFs ZOL group vs placebo group

ZOL significantly reduced the vertebral height lost rate (HLR) at 6, 12, 24, and 36 months

Figure 1: Vertebral height lost rate (%)

ZOL improved the visual analog scale (VAS), Oswestry disability index (ODI) scores, and bone mineral density (BMD)
Both the VAS and ODI scores of the two groups showed significant levels of pain relief after PKP surgery (preop. vs. postop., P < 0.05)
Compared to the placebo group, the VAS and ODI scores significantly declined in the ZOL group at 6, 12, 24, and 36 months (P < 0.05)

Table 1: Clinical outcomes

Outcomes	Zoledronic acid (N = 78)	Placebo (N = 76)	P value
Oswestry disability index score
Preop.	39.18 ± 4.78	39.32 ± 5.51	0.870
Postop. 1 week	27.60 ± 8.29	27.37 ± 8.38	0.862
Postop. 6 months	21.18 ± 6.96	24.30 ± 10.84	0.036*
Postop. 12 months	15.89 ± 6.61	19.42 ± 9.74	0.010*
Postop. 24 months	15.11 ± 6.44	19.43 ± 12.12	0.007*
Postop. 36 months	13.53 ± 6.70	21.36 ± 13.74	< 0.001
Complications (no., %)
Pyrexia	36 (46.15)	2 (2.63)	< 0.001
Myalgia	15 (19.23)	1 (1.32)	< 0.001
Influenza-like symptoms	15 (19.23)	0 (0)	< 0.001
Headache	9 (11.54)	1 (1.32)	0.024*
Arthralgia	9 (11.54)	1 (1.32)	0.024*
Cement leakage	6 (7.69)	5 (6.58)	0.789

Conclusion

3-year follow-up results showed that annual ZOL administration can minimize the risk of recompression vertebral fractures and new vertebral compression fractures, improving the clinical outcomes in initial PKP patients.