Study Finds Iliac Crest Bone the Graft of Choice for Fracture Nonunion

A study that investigated the efficacy of various “graft types” used as a biologic stimulant in the repair of fracture nonunion found that iliac crest bone graft (ICBG) remains the preferred option for this clinical situation.

The study, presented at the AAOS 2024 Annual Meeting by Jack C. Adams, a medical student at the George Washington University School of Medicine and Health Sciences, was a retrospective review involving 445 patients undergoing nonunion repair at a single academic medical center over the course of 7.4 years. The authors compared patients treated with ICBG versus various other graft types. Outcome measures included radiographic healing, time to union, postoperative complications, and need for revision. Patients were reevaluated at a minimum follow-up of 1 year.

A total of 311 patients (approximately 70 percent) were treated with an autogenous ICBG, obtained via a separate open approach. There was no difference between nonunion classification percentages between cohorts. The remaining 134 patients (approximately 30 percent) were treated with an alternative bone graft type (iliac crest aspirate, allograft, bone morphogenic protein, reamer-irrigation aspirator, and/or demineralized bone matrix [all others]).

Table 1 lists patient factors and outcomes between the two treatment groups. Compared with the all-others cohort, the ICBG group showed significantly greater healing success after a single nonunion surgery (94 percent ICBG 20 versus 79 percent for the others; P <0.001). additionally, cases in which icbg was used resulted in faster healing times for all of those who healed after one surgery; however, this finding only approached significance (4.8 months versus 5.5 months,>P = 0.07). The complication rate associated with ICBG harvest was 2.6 percent and included six incidents of iliac crest wound infection and two iliac wing fractures. Patients treated with persistent nonunions had more surgery than those who did heal. There was no difference in rates of positive culture at time of surgery (P = 0.911), postoperative fracture-related infection (P = 0.216), hardware failure (P = 0.854), or neurovascular injury (P = 0.358).</0.001).>

Mr. Adams told AAOS Now that the clinical takeaway is that “study subjects treated with ICBG showed significantly greater healing success after a single nonunion surgery. “When a patient presents with a symptomatic fracture nonunion requiring surgical intervention, our study suggests use of ICBG is preferred over other biological stimuli in prompting fracture union,” he said. “Additionally, the ICBG cohort demonstrated a faster time to healing. Although this only approached significance.”

The authors observed that their findings “support the long-held belief that ICBG is the ‘gold standard’ biologic agent for treatment of nonunion.” They explained that the osteogenic, osteoinductive, and osteoconductive nature of the ICBG make it “the perfect theoretical option,” while noting that “the added risk of complications associated with the harvest site—including numbness, postoperative and chronic pain to harvest site, iliac wing fracture, and infection—is key to understanding why other grafting types have been explored.”

The authors concluded: “Despite the increased risk of complications related to the harvesting process, we believe the relatively low frequency of these complications in this study combined with the remarkable success of ICBG use justifies the risk.” They noted that in their study, the complications at the graft harvest site were limited to wound infections and iliac wing fractures, while other studies have reported severe long-term pain and nerve injury at the harvest site. Acknowledging that “while the incidence is low, the impact on quality of life after these complications can be significant,” the authors stated, “Although there is a possibility for complications to occur, we believe the success of ICBG in achieving bone healing compared to other graft types—and thereby the decreased probability for a secondary revision surgery—outweighs the risks associated with its use.”

Addressing limitations of the study, Mr. Adams said that due to its retrospective design, selection bias is a possibility, as patients were not randomly assigned to the ICBG and alternative graft cohorts. Further, he said, “It is important to consider the heterogeneity of the alternative
grafting cohort—which comprised patients treated with iliac crest aspirate, allograft, bone morphogenic protein, reamer-irrigation aspirator, and demineralized bone matrix, each of which may have different healing properties and success rates.”

Finally, Mr. Adams said, the study did not account for potentially confounding factors, such as variations in surgical techniques, surgeon experience, or patient compliance with postoperative care, which may have influenced the outcomes.

Mr. Adams’s coauthors for “For Fracture Nonunion: Crest is Best, Better than the Rest When Put to the Test” are Sanjit R. Konda, MD; Abhishek Ganta, MD; Philipp Leucht, MD, PhD; Steven M. Rivero, MD; and Kenneth A. Egol, MD.