Preoperative Teriparatide Use on Insertional Torque of Pedicle Screws for Lumbar Fusion Surgery

This project aims to investigate any difference of insertional torque strength for osteoporotic patients with preoperative 1-month teriparatide injections versus those without. The increased insertional torque of pedicle screws during surgery after only 1 month of teriparatide use has also been studied. However, the effect of teriparatide on vertebral body bone mineral density (BMD) prior to and after fusion surgery has not been studied. The effects on screw insertional torque has also not been studied via a randomized controlled trial method.

For this project, adult patients (\>40 years) undergoing lumbar spinal fusion will be randomized to undergo teriparatide treatment for 1 month prior to surgery. Patients will have their baseline BMD assessed by DEXA scan must be considered as osteoporotic (\>2.5 SD from sex-matched young adult, or previous vertebral and/or femoral fractures) and indicated for spinal fusion surgery to undergo study. Exclusion criteria included Paget disease of bone, high laboratory tests for serum alkaline phosphatase or calcium, previous radiation treatment or fusion surgery to lumbar spine, bone tumors, metabolic bone disease, and hypersensitivity to teriparatide. Surgery involving single- or multi-level lumbar spinal fusion for any of the conditions: lumbar spinal stenosis, degenerative/isthmic/congenital spondylolisthesis, degenerative scoliosis. Only the surgeon and assessors will be blinded as patients will know their treatment arm.

Patients undergo a quantitative CT prior to initiation of teriparatide treatment. After one month of Teriparatide treatment, the drug is discontinued with another DEXA scan to see the changes in BMD. A quantitative CT will be performed after surgery and at 6 months postoperatively. Follow-up schedules include preoperative, immediate postoperative, postoperative 6 weeks, 3 months, 6 months, 12 months and at 24 months. At all follow-up timepoints, any complications, fusion demonstrated by cross-trabeculation on x-rays (with final confirmation at the 6 month CT), and objective questionnaires for quality of life including the EuroQoL 5 dimensions 5-level questionnaire (EQ-5D-5L), back pain numeric rating scale (NRS), osteoporosis assessment questionnaire-physical function (OPAQ-PF) and ambulatory status assessment (ASA) questionnaires will be recorded. Other quality-of-life scores include ODI and SF-36, along with adherence evaluation of osteoporosis treatment (ADEOS), osteoporosis attitude questionnaire and osteoporosis knowledge questionnaire. Once a patient is identified to be suitable for this protocol, they will need to be assessed by a medical social worker to be unable to afford this entire treatment regimen before institutional support for the drug treatment is provided.

Eligibility Criteria:
Inclusion Criteria:

* Patients must be osteoporotic: baseline BMD assessed by DEXA scan must be considered as osteoporotic (\>2.5 SD from sex-matched young adult, or previous vertebral and/or femoral fractures) and indicated for spinal fusion surgery

Exclusion Criteria:

* Paget disease of bone, high laboratory tests for serum alkaline phosphatase or calcium, previous radiation treatment or fusion surgery to lumbar spine, bone tumors, metabolic bone disease, and hypersensitivity to teriparatide