clinical investigation of montage in adults with spinal deformity undergoing pedicle subtraction osteotomy

Conditions: Fused Vertebrae; Ankylosing Spondylitis; Sagittal Deformities; Thoracolumbar Kyphosis

Summary: this study evaluates the difference in postoperative bleeding between two study groups, fda cleared montage settable resorbable hemostatic bone putty and standard of care (no bone hemostat) during pedicle subtraction osteotomy procedures.

pedicle subtraction osteotomy (pso) is a surgical option for treating several spinal deformities. it has been utilized in alignment disorders of the fused spine, in the lumbar spine to treat large sagittal deformities and in patients with ankylosing spondylitis with thoracolumbar kyphotic deformity. pso typically results in substantial loss of blood (as much as 2l) with a significant portion of the loss likely occurring at the osteotomy surfaces post-surgically. the control of peri-operative blood loss is considered a critical issue by spine surgeons. a variety of methods have been proposed for the reduction of blood loss during or immediately after spine surgery, including preoperative use of erythropoietin, autologous blood, cell salvage, intra-operative controlled hypotension, and the use of anti-fibrinolytic drugs. bone hemostats have traditionally not been part of the standard of care to promote hemostasis probably because most traditional options (e.g., bone wax) are nonabsorbable and thus might interfere with fusion at the osteotomy site. montage is a settable (hardening) bioabsorbable polymer and hydroxyapatite/beta tricalcium phosphate based putty, used in the control of bleeding from bone during spine, orthopedic, craniomaxillofacial, thoracic and other surgical procedures, and has been fda cleared.

Eligibility criteria:
inclusion criteria: * presence of spinal deformity requiring a pso at a single site level, such as for patients with thoracolumbar kyphotic deformity, sagittal imbalance, and spinal global malalignment. * non-smokers (have proven to quit smoking for at least 6 months prior to surgery) and current smokers. * female subjects of childbearing potential must be willing to use acceptable methods of contraception (birth control pills, barriers, or abstinence). a pregnancy test at the week 0 visit must be administered, and must be negative, for inclusion into the study. * subject understands and is willing to participate in the clinical study and can comply with required visits and the follow-up regimen. * subject has read and signed the institutional review board (irb)/independent ethics committee (iec) approved informed consent form before screening procedures are undertaken. exclusion criteria: * subjects whose spinal deformity is deemed by the investigator to be of such severity that a possible surgical intervention would be either harmful or not warranted. * subjects with morbid obesity (i.e. a body mass index \[bmi\] ≥ 40). * subjects who have a known allergy to the components of montage. * subjects who are non-mobile (i.e. not ambulatory, or have significant impairment of their mobility making them completely bedridden). * subjects who, in the opinion of the investigator, show evidence of infection, cellulitis, and/or osteomyelitis. * subjects with abnormally low platelets, abnormal coagulation parameters, or with documented bleeding disorders, including a prior history of excessive bleeding during surgery. * subjects with a history of a malignancy, not in remission for five years or more, or a newly diagnosed malignancy, treated with cytotoxic therapies or radiation therapy. * subjects on any investigational drug(s) within 30 days preceding randomization (i.e. week 0); or subject or physician anticipates use of any of these therapies by the subject during the course of the study. * subjects with: (i) alcohol abuse as recorded by an average daily intake of \> 4 units in females, \> 5 units in males (i.e. 1 oz. of spirit, glass of wine, or can of beer per unit). (ii) drug abuse as evidenced by the subject's use of illegal drugs or prescription drugs that have not been prescribed for him/her. * subjects with one or more medical conditions, as determined by medical history, including renal, hepatic, hematologic, active auto-immune or immune diseases that, in the opinion of the investigator, would make the subject an inappropriate candidate for this study. * subjects with a history of osteoporosis, as defined by imaging, or on medication for osteoporosis or documented fracture of fragility (hip fracture, osteoporotic compression fracture, distal radius fracture). if there are any concerns these may be arbitrated by the study pi. * subject has previously participated in any montage trial. * subjects who are unable to understand the aims and objectives of the trial and/or unwilling to return for the follow-up examinations.