Does Demineralized Bone Matrix Affect the Nonunion Rate in Arthroscopic Ankle Arthrodesis?

SLR - January 2023 - Aria Mansoori, DPM, PGY3

Title: Does Demineralized Bone Matrix Affect the Nonunion Rate in Arthroscopic Ankle Arthrodesis?

Reference: Schlickewei C, Neumann JA, Yarar-Schlickewei S, Riepenhof H, Valderrabano V, Frosch KH, Barg A. Does Demineralized Bone Matrix Affect the Nonunion Rate in Arthroscopic Ankle Arthrodesis? J Clin Med. 2022 Jul 4;11(13):3893. doi: 10.3390/jcm11133893. PMID: 35807177; PMCID: PMC9267684.

Level of evidence: III

Reviewed by: Aria Mansoori, DPM, PGY3

Residency Program: MedStar Health

Podiatric Relevance: 
Demineralized bone matrix (DBM) has been shown to improve union rates in orthopedic surgery. There are not many studies on bone graft substitutes in foot and ankle surgery that show evidence of DBM improving (or not improving) outcomes. Fusions in the foot and ankle have a 12% nonunion rate with ankle fusions being one of the higher rates of nonunion for an isolated fusion procedure, with rates of nonunion reported as high as 40%. 
Ankle arthritis is the most common diagnosis leading to the treatment of ankle fusion. There are open and minimally invasive techniques for ankle arthrodesis. Nonunion is the most common complication. To increase the likelihood of union, surgeons may choose to add DBM to their fusion site. This study aimed to compare union rates and complication rates in patients undergoing arthroscopic ankle fusions with and without DBM. Additional outcomes include complication rates. 

Methods: 
A retrospective analysis of 58 ankles with arthroscopic ankle fusions performed between March 2002 and May 2016 was performed. Inclusion criteria were: severe ankle joint arthritis, failure of conservative treatment, over the age of 18, arthroscopic ankle arthrodesis, and at least 6 months of radiographic follow up. Open surgeries and revision surgeries were excluded. 31 ankles used DBM and 27 were performed without the use of DBM.

Results:
Ankle fusions treated with DBM or without DBM had no statistical difference in preoperative joint deformity. The nonunion rate was 12.9% for the DBM ankle fusion group. The nonunion rate was 14.8% for the group of ankle fusions without use of DBM. There is no statistical difference in nonunion rate with use of DBM or without DBM in ankle fusions. Additionally, there was no difference in rates of complications such as wound infections, blood clots, or return to OR. 

Conclusions:
As podiatric surgeons, we often have various choices when it comes to surgical approaches and procedures. With new technology, there have become minimally invasive ways of performing traditionally open procedures. Arthroscopic ankle fusions have been shown to increase the speed of postoperative recovery as well as decrease wound complications. This study looked at arthroscopic ankle arthrodesis with and without the use of DBM and compared nonunion and complication rates. Ankle fusions using DBM had a 12.9% nonunion rate as opposed to the non DBM group which had a 14.8% nonunion rate. The rate of nonunion was a little better in the DBM group, but it was not statistically significant. Secondary outcome measures showed no difference in complication rates, including blood clots, wound infections, or return to OR. Additional things to consider as a foot and ankle surgeon would be use of DBM or other bone graft substitute in a primary ankle arthrodesis versus a revision arthrodesis. Cost and availability may also play a role. DBM was not proven to negatively impact fusion rate or complications.