Bone graft materials for posterolateral fusion made simple: a systematic review

Area of Science:

• Spinal Surgery
• Biomaterials Science
• Orthopedics

Background:

• Iliac crest bone graft (ICBG) is a traditional standard for lumbar fusion but has donor site morbidity.
• Research into bone graft substitutes is extensive, yet consensus on optimal materials for fusion remains elusive.
• Posterolateral lumbar fusion necessitates effective bone graft materials to achieve successful outcomes.

Purpose of the Study:

• To systematically review and evaluate bone graft materials for maximizing fusion rates in posterolateral lumbar fusion surgery.
• To assess the efficacy of various autograft, allograft, and synthetic bone graft options.
• To identify current trends and optimal combinations for lumbar spine fusion.

Main Methods:

• A PRISMA-compliant systematic review of PubMed, EMBASE, and Web of Science databases.
• Inclusion of clinical human research studies from 2000-2015 focusing on posterolateral lumbar fusion with reported radiographic fusion rates.
• Analysis of studies evaluating iliac crest bone graft (ICBG), local allograft (LAG), bone morphogenetic proteins (BMPs), demineralized bone matrix (DBM), and bone marrow aspirate (BMA).

Main Results:

• 48 studies were included, assessing fusion rates via radiographs and/or CT scans.
• Combinations involving ICBG yielded mean fusion rates from 68.0% to 91.5%.
• Local allograft (LAG) and its combinations showed mean fusion rates from 75% to 95.5%, with LAG+BMA demonstrating the highest efficacy. Allograft alone had a mean fusion rate of 40.0%.

Conclusions:

• Layered allograft with bone marrow aspirate (LAG+BMA) demonstrated the highest fusion rate in this review.
• Most analyzed bone graft materials, excluding allograft alone, exceeded 70% fusion rates, indicating comparable outcomes.
• The ideal bone graft should integrate osteoconductive, osteoinductive, and osteogenic properties for optimal spinal fusion.