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

Abstract

Demineralized bone matrix (DBM) has been shown to have positive effects on union rates in many orthopedic subspecialties; however, minimal evidence exists about bone graft substitutes in foot and ankle surgery. The purpose of this study is to compare nonunion rates in arthroscopic ankle arthrodesis in patients receiving DBM with those without. We hypothesized DBM to be associated with a decreased risk of nonunion. This retrospective review includes 516 consecutive ankle arthrodesis cases from March 2002 to May 2016. Of these, 58 ankles (56 patients) that underwent primary arthroscopic ankle arthrodesis met the inclusion criteria, and 31 of these ankles received DBM, while 27 did not. Nonunion was assessed by clinical examination and routine postoperative radiographs. If nonunion was suspected, a computed tomography (CT) scan was performed. The primary outcome measure was nonunion rate. Secondary outcome measures included wound complications, return to operating room (OR), and rate of postoperative deep vein thrombosis (DVT) or pulmonary embolism (PE). From the study cases, 58 were available for final follow-up. The average age was 55.9 years (±17.4), and mean follow-up was 43.0 months (range 6.3–119.4). There was no difference in nonunion rate in patients who received DBM (4/31, 12.9%) versus those who did not (4/27, 14.8%) (p = 0.83). Similarly, when comparing the two groups, there were no statistically significant differences in superficial wound complications (6.5% vs. 3.7%, p = 1.0) or rate of return to OR (29% or 0.037/person-years vs. 37% or 0.099/person-years; p = 0.20). No major complications including deep wound infections, DVTs, or PEs occurred. This is the largest study to directly compare nonunion rates and complications for patients receiving DBM versus those who did not in primary arthroscopic ankle arthrodesis. No significant association was found between DBM usage and risk of nonunion, wound complications, return to OR, or postoperative DVT or PE development.

Comparative Studies of Bone Graft and Orthobiologics for Foot Ankle Arthrodesis: A Critical Review

“…29 The surgical methods used in the included studies in this review and the indications for fusion were variable, and this constitutes a major limitation. 7,23,25,26,32 Posttraumatic osteoarthritis or primary osteoarthritis was likely the most common indication for ankle fusion; however, patients with other diagnosis such as rheumatoid arthritis or Charcot disease were also included in the included studies, but the outcomes were not analyzed by surgical indication. 4,11,[15][16][17]31,32 In the surgical techniques, there was variability in the fixation construct used among the included articles and occasionally among the patients included in the same study population such as plate and screws, screws only, or intramedullary nails and/or combination of the above.…”

“…The interpretation of the outcomes in clinical trials can be challenging given multiple follow-up points and the utilization of functional outcomes scores in combination with the corresponding variable minimal clinically important difference values that have not always be validated for the diagnosis of interest. 32 As an example, most of the reported minimal clinically important difference values for FFI or AOFAS stemmed from study populations undergoing common procedures such as correction of hallux valgus and not necessarily ankle/hindfoot fusion. 33,34 In addition, there was a lack of consistency in the time interval and definition of nonunion versus delayed-union, and the defined benchmark for successful fusion varied greatly, as well as the level of accuracy in the imaging method used to assess fusion (CT versus plain radiograph).…”

“…7,23,25,26,32 Posttraumatic osteoarthritis or primary osteoarthritis was likely the most common indication for ankle fusion; however, patients with other diagnosis such as rheumatoid arthritis or Charcot disease were also included in the included studies, but the outcomes were not analyzed by surgical indication. 4,11,[15][16][17]31,32 In the surgical techniques, there was variability in the fixation construct used among the included articles and occasionally among the patients included in the same study population such as plate and screws, screws only, or intramedullary nails and/or combination of the above. The latter can have a notable effect on the interpretation of outcomes, and this review categorizes the study based on the types of biologic agents used in comparative series with somewhat similar surgical fixation technique between the study groups.…”

“…Notable heterogeneity was noticed among the non-RCT studies comparing the effectiveness of various bone graft options and orthobiologics in the healing rates and functional outcomes after foot and ankle arthrodesis. [15][16][17][18]20,21,[23][24][25][26]30,32 The heterogeneity among those studies can be attributed to the different types of bone grafts reported, the various combinations of autograft or allograft tissue with biologic molecules, lack of more than one study analyzing the effect of a certain biologic agent or medication on bone healing in ankle/foot fusion surgery (except for the BMP, see section above), and inconsistency in the reported clinical outcomes. [15][16][17][18]20,21,23,24,27,30,32 More research is necessary to understand the role of allograft bone tissue and/or orthobiologics as alternatives to autograft use to facilitate bone healing in patients undergoing foot and ankle arthrodesis.…”

“…The latter can have a notable effect on the interpretation of outcomes, and this review categorizes the study based on the types of biologic agents used in comparative series with somewhat similar surgical fixation technique between the study groups. 26,27,30,32 Again, the heterogeneity among patient characteristics, surgical fixation method, indication for fusion, and biologic agent used are factors that need to be taken into account when interpreting the results of this review.…”