to speed the healing process. He says fusion rates are 92% to 95% and
healing takes 3 to 4 months.
Bone substitutes
Many bone alternative materials designed to help new bone growth
are available in various moldable forms — including injectable paste,
putty or gel. Your surgeons might prefer a certain material, but they
should focus on using cost-effective products that demonstrate osteo-
conduction and osteoinduction. Here's a quick review:
• Bone morphogenetic protein (BMP) is a naturally occurring pro-
tein found in human bone and is a strong stimulant for bone formation,
according to Dr. Corenman. He says the substance has significantly
improved outcomes of spinal fusions involving iliac crest bone grafts.
Without the use of BMP, Dr. Corenman says fusions following posterior
fusion surgeries typically take 1 year to mature and have a fusion per-
centage with local bone grafts between 85% and 90%. When using BMP,
Dr. Corenman's patients achieve fusion in 5 to 6 months and have a
fusion percentage of 99%.
The FDA has approved BMP for use during posterior spine fusion
procedures, including transforaminal lumbar interbody fusion (TLIF)
and posterior lumbar interbody fusion (PLIF). Dr. Corenman says
many insurance companies now reimburse for BMP use during PLIF,
but acknowledges that many surgeons don't use the protein because
of problems getting pre-authorization from payers due to its expense.
Some surgeons instead combine synthetic bone extender grafts
— such as a collagen-calcium sulfate mixture — with autografts or
use stem cell derivatives aspirated from the iliac crest to increase
fusion rates.
• Demineralized bone matrix (DBM) is allograft bone that has had
its mineral content (calcium) removed to leave behind protein-based
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