‘Unacceptable’ failure rate discovered with iliac crest aspirate injections

Investigator advises against using ‘simplistic’ procedure: 67% of study cases failed to heal.

Issue: February 2007

PHOENIX — While some surgeons look to percutaneous iliac crest aspirate injections as an alternative to open bone grafting for nonunions, a new study reveals high failure rates with the procedure.

Researchers reviewing 54 procedures using iliac crest aspirate injections for the treatment of delayed and ununited long bone fractures found that 67% failed to heal.

"Our patient population demonstrated marginal results with regard to healing and had an unacceptable high rate of failure with this simplistic procedure," Kevin J. Quigley, MD, of St. Louis, said during his presentation at the Orthopaedic Trauma Association annual meeting. "Based on these results, we cannot recommend routine use of this procedure that was performed in this study."

During a minimum 2-year follow-up, Quigley and his colleagues discovered that only 16 of the 44 patients included in the study achieved healing after one round of treatment.

"There was no significant difference noted between the group of patients that healed vs. those who did not with regards to mode of skeletal stabilization, fracture grade — whether it was closed vs. open — history of smoking or type of nonunion," Quigley said.

Cellular concentrate

Investigators from St. Louis University School of Medicine retrospectively reviewed the cases of 51 patients who underwent percutaneous injection of iliac crest aspirate. They performed the procedures at a single center between 1995 and 2003, according to the study abstract. The patients ranged between 16 and 79 years old and had delayed or ununited long bone fractures for more than 3 and 6 months, respectively. The cohort included delayed unions or nonunions in the tibia, femur and humerus.

During the procedure, surgeons used large bore needles to extract marrow from patients' anterior or posterior iliac crests in 4-cc to 5-cc increments. They placed the aspirate in a centrifuge for 10 minutes to obtain a cellular concentrate. "The cellular concentrate was subsequently injected directly into the site of the nonunion under fluoroscopic guidance," Quigley said.

The surgeons extracted an average 48 cc of aspirate and injected an average 28 cc of cellular concentrate into the defect. "The procedures themselves yielded no intraoperative or short-term postoperative complications," Quigley said, though some patients reported irritation at the aspiration and injection sites.

In the study, researchers aspirated marrow in increments of 4 cc to 5 cc.

Images: Quigley K

To extract the aspirate, surgeons placed a large bore needle between the inner and outer table of the iliac crest.

Limited success

The researchers excluded cases with inadequate follow-up or aspirates combined with composite graft materials and noted factors that could have influenced union such as the type of mechanical stabilization, smoking and fracture type.

Overall, they included 44 patients in the final analysis and found that most patients did not achieve union with the treatment. Twenty-six of 44 patients or 59% treated with aspiration injection did not heal their nonunion, Quigley said. Sixteen of 44 or 36% went on to bone union after their first procedure. Two patients who underwent a second injection of iliac crest aspirate also healed, according to the abstract.

"Thirty-six of the 54 total procedures performed or 67% during the 8-year [study] period failed," Quigley said. While researchers found an overall high failure rate for the long bones included in the study, they discovered that femurs had the highest rate of continued nonunion.

Twenty patients who did not achieve union from the iliac crest aspirate injections underwent surgical procedures at a later time. "Of these 20, 16 involved some form of open bone grafting procedures," Quigley said. "Of those, 13 or 81% of these ultimately healed," he said.

Despite the study results, Quigley said new and more complex techniques involving aspirated grafts or higher cellular concentrations might yield better outcomes. "These techniques, in combination, may demonstrate an increased clinical efficacy for the use of autogenous aspirate grafting technologies and we feel that further randomized control trial studies in this area are necessary," he said.

For more information:

Watson JT, Quigley KJ and Mudd CD. Percutaneous injection of iliac crest aspirate for the treatment of long bone delayed union and nonunion. #13. Presented at the Orthopaedic Trauma Association 22nd Annual Meeting. Oct. 4-7, 2006. Phoenix.

Kevin J. Quigley, MD, house staff resident orthopedist, St. Louis University School of Medicine, 1402 South Grand, St. Louis, MO 63104; 314-577-8850; quigleyk@slu.edu. None of the study's authors received anything of value regarding the research or had any disclosures relevant to this study.