Spinal medial branch nerve root block (MBNB) intervention compared to standard care-vertebroplasty (VP) for the treatment of painful osteoporotic vertebral fractures in frail, older hospitalised patients: a feasibility study

Abstract

Our study aimed to assess the feasibility outcomes comparing spinal medial branch nerve root block intervention to standard care vertebroplasty for the treatment of painful osteoporotic vertebral fractures in frail, hospitalised older patients. We found the study to be feasible and now propose a clinical effectiveness, cost effectiveness and safety evaluation.

Introduction: Vertebroplasty (VP) is a key-hole procedure involving injection of bone cement into a fractured vertebral body, to reduce pain and increase vertebral body stability, although it is associated with a small risk of complications, particularly in frail, older hospitalised patients. Medial branch spinal nerve block (MBNB) may be an alternative treatment to alleviate pain symptoms, with less complications; however, no study has prospectively compared the clinical effectiveness, cost-effectiveness and safety of MBNB to VP, in frail, older hospitalised patients. The aim of our study was to conduct a 1st stage feasibility study, exploring recruitment, retention and several outcomes measures (means and SDs), together with qualitative interviews to assess participant and clinician views, to inform a definitive larger study.

Methods: We conducted a two-arm feasibility randomised controlled trial with participants allocated to continue with routine surgical care-VP or MBNB treatment, with an embedded qualitative study. Data was collected at baseline, week 1, 4, and week 8.

Results: Out of 40 eligible patients, 30 (75%) consented to take part in the study. The overall median time from randomisation to intervention was 3 days, IQR 1-7 days, 5 (1-7) days for VP and 2 (1-3) days for MBNB. Median (IQR) length of hospital stay for the VP group was 20 (8) days and for the MBNB 15(22) days. The proportion of completeness of outcome data collection at weeks 1, 4 and 8 was at least 77%: 14 (100%), 12 (85.7%) and 11(78.9%) for VP and 13 (100%), 12 (92.3%) and 10 (76.8%) for MBNB, respectively. There were no significant difference in the clinical outcomes or adverse events between the two groups.

Discussion: Our study was feasible in achieving is target recruitment, participants adhered to the randomisation and at least 77% completeness of data at the 8 week end-point (target 75%). We now plan to conduct a definitive clinical effectiveness, cost effectiveness and safety outcome study, comparing VP to MBNB in frail, older patients hospitalised with an acute vertebral osteoporotic fracture.

Keywords: Frail older; Hospitalised; Medial branch spinal nerve block; Osteoporosis; Vertebral osteoporotic fracture; Vertebroplasty.