SAN FRANCISCO — Typical bone union rates after posterior lumbar interbody fusion may be expected in women who take bisphosphonates for longer than 3 years prior to surgery, according to data presented at the International Society for the Study of the Lumbar Spine Annual Meeting, here.
“At 2-year follow-up, we cannot find any statistical difference between the two groups’ fusion rates,” Si Young Park, MD, PhD, said.
Because the use of bisphosphonates can be associated with such complications as atypical hip fracture, osteonecrosis of the jaw and delayed fracture healing, Park, of the Department of Orthopaedic Surgery at Korea University College of Medicine, in Seoul, and colleagues explored their impact in a retrospective study of 95 postmenopausal women treated from 2008 to 2012.
All the patients underwent conventional open posterior lumbar interbody fusion (PLIF) with bone graft obtained from the laminectomy; 62 patients used bisphosphonates long-term (BP group), and 33 patients did not use bisphosphonates (control group). The study’s endpoint was 2 years.
The researchers identified four nonunions in the control group and 10 nonunions in the BP group; however, the clinical outcomes based on the Oswestry Disability Index and VAS scores improved in both groups.
Despite having extremely decreased serum cross-linked C-telopeptide levels (P < .05), the BP group had an 82% fusion rate compared with an 87% fusion rate in the control group at 2 years.
“However, at 6 months after surgery, [the] bone union rate in the BP group was somewhat lower than controls,” according to Park.
“This is the first study of the effect of long-term preoperative bisphosphonate usage on spine fusion,” he said. – by Susan M. Rapp
Park SY, et al. Paper #47. Presented at: International Society for the Study of the Lumbar Spine Annual Meeting; June 8-12, 2015; San Francisco.
Disclosure: Park reports no relevant financial disclosures.