In the JournalsPerspective

Subtalar arthrodesis with adipose-derived cellular bone matrix had lower fusion rate vs autograft

J. Chris Coetzee

Use of adipose-derived cellular bone matrix in subtalar arthrodesis augmentation had lower rates of radiographic fusion compared with autograft, according to results.

J. Chris Coetzee, MD, and colleagues randomly assigned 140 patients undergoing subtalar arthrodesis to receive adipose-derived cellular bone matrix implantation or autograft. Researchers collected standard three-view weight-bearing radiographs at 6 weeks, 3 months, 6 months, 1 year and 2 years postoperatively and CT scans at 6 months postoperatively. Fusion, defined at 45% or greater osseous bridging across the posterior facet of the subtalar joint as measured on CT scan, was considered the primary radiographic endpoint, and secondary endpoints included American Orthopaedic Foot & Ankle Society Ankle-Hindfoot Scale, foot function index-long form, SF-12, VAS pain scale, adverse events and complications.

Overall, 52 and 57 patients underwent arthrodesis with adipose-derived cellular bone matrix and autograft, respectively. Results showed 30.8% of patients in the adipose-derived cellular bone matrix group and 54.4% of patients in the autograft group achieved fusion at 6 months as measured on CT. When assessed by clinical and radiographic evaluation, 78.8% of patients in the adipose-derived cellular bone matrix group and 87.7% of patients in the autograft group achieved fusion at 6 months. Both groups had significant functional improvement from baseline in quality of life outcome measures, according to results. Researchers noted 10.5% of patients in the autograft group experienced serious adverse events vs. 23.1% of patients in the adipose-derived cellular bone matrix group.

Coetzee told Healio.com/Orthopedics, “There are a few take-home messages [to this study]: 1) The subtalar joint continues to be a complicated joint to fuse, no matter what message is used; 2) Always looking at new technology objectively before adopting it as gospel; [and] 3) Standard X-rays are of very little, if any value to determine whether the subtalar joint is fused. The only reliable imaging study is a CT scan.” – by Casey Tingle

 

Disclosures: Coetzee reports he received grants from AlloSource and other support from Integra, Paragon, Arthrex, the American Orthopaedic Foot & Ankle Society, American Academy of Orthopaedic Surgeons, Zimmer, AlloSource, Tornier, Foot and Ankle International, Biomet and Stryker. Please see the study for a list of all other authors’ relevant financial disclosures.

J. Chris Coetzee

Use of adipose-derived cellular bone matrix in subtalar arthrodesis augmentation had lower rates of radiographic fusion compared with autograft, according to results.

J. Chris Coetzee, MD, and colleagues randomly assigned 140 patients undergoing subtalar arthrodesis to receive adipose-derived cellular bone matrix implantation or autograft. Researchers collected standard three-view weight-bearing radiographs at 6 weeks, 3 months, 6 months, 1 year and 2 years postoperatively and CT scans at 6 months postoperatively. Fusion, defined at 45% or greater osseous bridging across the posterior facet of the subtalar joint as measured on CT scan, was considered the primary radiographic endpoint, and secondary endpoints included American Orthopaedic Foot & Ankle Society Ankle-Hindfoot Scale, foot function index-long form, SF-12, VAS pain scale, adverse events and complications.

Overall, 52 and 57 patients underwent arthrodesis with adipose-derived cellular bone matrix and autograft, respectively. Results showed 30.8% of patients in the adipose-derived cellular bone matrix group and 54.4% of patients in the autograft group achieved fusion at 6 months as measured on CT. When assessed by clinical and radiographic evaluation, 78.8% of patients in the adipose-derived cellular bone matrix group and 87.7% of patients in the autograft group achieved fusion at 6 months. Both groups had significant functional improvement from baseline in quality of life outcome measures, according to results. Researchers noted 10.5% of patients in the autograft group experienced serious adverse events vs. 23.1% of patients in the adipose-derived cellular bone matrix group.

Coetzee told Healio.com/Orthopedics, “There are a few take-home messages [to this study]: 1) The subtalar joint continues to be a complicated joint to fuse, no matter what message is used; 2) Always looking at new technology objectively before adopting it as gospel; [and] 3) Standard X-rays are of very little, if any value to determine whether the subtalar joint is fused. The only reliable imaging study is a CT scan.” – by Casey Tingle

 

Disclosures: Coetzee reports he received grants from AlloSource and other support from Integra, Paragon, Arthrex, the American Orthopaedic Foot & Ankle Society, American Academy of Orthopaedic Surgeons, Zimmer, AlloSource, Tornier, Foot and Ankle International, Biomet and Stryker. Please see the study for a list of all other authors’ relevant financial disclosures.

    Perspective
    Andrew R. Hsu

    Andrew R. Hsu

    Will we ever be able to completely replace bone autograft? This paper provides one piece of evidence that the answer is likely no. 

    In this prospective, multicenter, randomized controlled trial comparing adipose-derived cellular bone matrix (ACBM) with autograft (mainly tibia) in subtalar fusions, ACBM had lower fusion rates and higher complications compared to autograft. While both groups had improved outcome scores at 6 months postop, CT analysis showed significantly higher nonunion rates in the ACBM group. 

    As more novel bone graft substitutes come to market, it is critical that we carefully evaluate the safety and efficacy of each one with high-quality studies to better determine what works and what doesn’t. While a product should work in theory and basic science, we have been shown time and time again that whether it produces a clinically relevant benefit in patients is an entirely different matter. 

    Of note, ACBM is no longer commercially available as of December 2017. In my opinion, bone autograft will always be a viable option to assist with bony fusion as we continually to search for new and improved potential substitutes that can stand up to the test of randomized controlled trials.

    • Andrew R. Hsu, MD
    • Chief, division of foot and ankle surgery Assistant clinical professor of orthopedic surgery
      University of California, Irvine
      Orange, California

    Disclosures: Hsu reports he is a paid consultant for Arthrex Inc.