Introduction: Few studies have reported on adjunctive use of biologic therapies to promote bony fusion and their prevention of future adjacent level vertebral body compression fractures. Teriparatide (Forteo) a drug commonly used for the treatment of the osteoporosis, rapidly enhances bone formation and increases bone strength by selectively promoting osteoblast activity. Forteo has been shown to directly stimulate bone formation and improve bone density, but there is a lack of evidence regarding its use in spinal fusion and nonoperative spinal fracture management. We have used Forteo following spine surgery in a selective cohort of patients who were at risk for pseudoarthroses, and in select fractures which were treated nonoperatively.

Methods: Radiographs of 23 patients with documented osteoporosis or spinal fractures were reviewed before and after a minimum of 12 months of Forteo treatment. Among them, 13 patients were treated with Forteo (minimum 3 months) (group I) after surgical fusion procedures, and 10 patients who sustained spinal fractures were treated with Forteo without surgery (group II). All patients were followed at 3 weeks, 6 weeks, 3 months, 6 months and one year with radiographs to confirm final bony fusion. Furthermore, for the surgical cohort (Group1) we measured radiographic fusion and bony cortico-cancellous bridging on postoperative CT scans. For the fracture population treated with Forteo alone, we measured kyphosis and wedge angle of the fractured vertebral body, and ratios of anterior, middle, and posterior heights of the fractured body to posterior height of the normal adjacent level vertebrae to ascertain any degree of adjacent level collapse or asymptomatic progression of osteoporosis.

Results: The progression of spinal cortical and cancellous fusion was shown in 100% of our surgical cohort (Group 1). At the last follow-up, mean increments of kyphosis and wedge angle were unchanged in Group 2 (6.3 and 5.3 deg) and in adjacent level vertebral bodies. In both groups, Forteo also demonstrated improved post treatment bone mineral densities in both groups.

Conclusions: Forteo has the unique potential as a biological non-invasive strategy to improve and encourage bony healing and fusion in at risk patients while halting detrimental side effects of osteoporosis.

Patient Care: This study demonstrates that for patients who have a documented pseduoarthrosis and in select fractures which are treated nonoperatively can achieve successful bony consolidation using Forteo as Biologic therapy.

Learning Objectives: Each spinal fusion and fracture carries the potential to develop a mal union, or pseudoarthrosis. Biologic therapies to promote and/or accelerate an otherwise problematic fusion may constitute a new treatment modality for patients who are at risk.

References: Clin Cases Miner Bone Metab. 2013 Sep;10(3):210-2. Tensile type of stress fracture neck of femur: role of teriparatide in the process of healing in a high risk patient for impaired healing of fracture. Malhotra R, Meena S, Digge VK.