[Posterior medial branch block for persistent pain after percutaneous vertebral augmentation in osteoporotic...

To evaluate the short-and medium-term efficacy of posterior medial branch block in the treatment of persistent pain after percutaneous vertebral augmentation.

From January 2018 to January 2023, a total of 1, 062 patients with osteoporotic vertebral compression fractures underwent percutaneous vertebral augmentation. Among them, 32 elderly patients who experienced persistent low back pain after surgery and subsequently received posterior medial branch block and cryoablation were included. Six patients died during follow-up, leaving 26 patients for final analysis (1 male, 25 females). The mean age was (82.96±5.66) years (ranged, 76 to 94 years). The mean body mass index was (23.76±3.08) kg·m^-2(ranged 18.1 to 27.2 kg·m^-2). The bone mineral density T-value ranged from -2.5 to -4.3 with a mean of (-3.09±0.56). The mean volume of bone cement injected was 6.00 (5.38, 7.00) ml. Fracture locations were T₁₁ (2 cases), T₁₂ (7 cases), L₁ (10 cases), L₂ (6 cases), and L₃ (1 case). The mean interval from vertebral augmentation to block treatment was (7.12±2.22) months (rangd 6 to 12 months). The vertebral augmentation procedures were percutaneous kyphoplasty(PKP) in 12 cases and percutaneous vertebroplasty (PVP) in 14 cases. At the 2nd week, 3rd month, and 6th month after the block, the numerical rating scale(NRS), Oswestry disability index(ODI), patient satisfaction, and pain relief rate at the 6th month were evaluated. Relationships between pain relief rate at the 6th month after the last treatment and possible influencing factors were analyzed.

Compared with X-ray films after percutaneous vertebral augmentation, the X-ray films before block showed an increase in kyphotic angle and vertebral compression rate, with statistically significant differences(P<0.05). At the 2nd week, 3rd month, and 6th month after posterior medial branch block and cryoablation, NRS and ODI scores were significantly lower than before the block(P<0.05). Among the 26 patients, 5 received additional cryoablation. At the 6th month after the last treatment, 19 patients reported excellent or good satisfaction. Univariate binary Logistic analysis showed all P>0.05, and no independent factor affecting final satisfaction or pain relief at 6 months after the last treatment was identified.

Posterior medial branch block(with cryoablation) can effectively improve short-and medium-term symptoms and function in patients with persistent axial low back pain after percutaneous vertebral augmentation for osteoporotic vertebral fractures.