MON-365 Novel Use of Abaloparatide to Augment Spinal Fusion in Patient Undergoing Cervicothoracic Revision Surgery

Objective To present a case of using Abaloparatide (PTHrP 1–34 analogue) to promote spinal fusion in a patient with history of cervical instability s/p multiple cervical operations with non-union. Case Presentation 66 year-old female with a history of multiple sclerosis, obesity and hypothyroidism underwent neurosurgical evaluation of neck pain. She was found to have cervical spinal stenosis causing neck pain, radiculopathy, motor deficits and ataxia. Initially underwent anterior cervical discectomy and fusion which temporarily alleviated symptoms before suffering nonunion. Subsequently underwent two additional surgeries which also eventually failed. She presented to our facility for revision corpectomy and spinal fusion. Given her history of nonunion, endocrinology was consulted for evaluation of metabolic bone disease. No known personal or family history of metabolic bones disease. No history of chronic steroid use. Initial endocrine evaluation excluded common pathologies. A decision was made to pursue anabolic osteoporosis therapy to attempt to augment the spinal fusion process. Patient started on Abaloparatide 80mcg daily 2 weeks post procedure with planned 12-week therapy course. Cervical CT at 3 and 6 months showed post-surgical cervicothoracic fusion with no signs of non-union. Discussion Abaloparatide is a 34 amino acid synthetic analogue of parathyroid hormone related peptide (PTHrP) which works by selectively activating PTH1 receptor found on osteoblasts. Currently anabolic therapies are only FDA approved for treatment of osteoporosis but there is reported off label use in cases of spinal fusions, arthroplasty and fracture healing. Studies have shown that presence of PTH and PTHrP are necessary for fracture healing. Animal studies have also shown that intermittent PTH promotes spinal fusion. This case represents a novel use for Abaloparatide to augment spinal fusion in a human clinical model. Conclusion Further studies are warranted to better understand mechanism of action, drug timing and duration for optimal treatment of anabolic therapies in bone fractures and healing. The use of anabolic therapies like Abaloparatide can be considered in patients undergoing spinal fusion surgery at high risk for non-union or undergoing revision for failed fusion.ReferencesO’Loughlin PF, Cunningham ME, Bukata SV et al. Parathyroid Hormone Augments spinal fusion, fusion mass, and fusion mass quality in a rabbit spinal fusion model. Spine 2009 January; 34: 121–130