A study investigating surgical fixation of unstable chest wall and flail chest injury found no improvement in ventilator-free days (VFDs) or other outcomes compared to nonsurgical treatment across the entire patient population. However, the study, presented as a poster at the AAOS 2021 Annual Meeting in San Diego, did record a lower rate of mortality with surgical treatment. Also, in the subset of patients who were intubated and mechanically ventilated at the time of randomization, results showed improvement in VFDs and length of hospital stay.

Presenting author Niloofar Dehghan, MD, chief of trauma at the CORE Institute in Phoenix and an associate professor at the University of Arizona College of Medicine, said the idea for the study came to her during her orthopaedic trauma residency rotation, when she saw a patient with a severe flail chest injury who “was having a hard time being weaned off the ventilator due to pain from his rib fractures.” The intensive care unit (ICU) team asked the orthopaedic trauma team “to fix his ribs,” Dr. Dehghan recalled. “The procedure was very rare at the time, and it captured my attention. I started looking at outcomes of flail chest injuries, and I thought it would be interesting to look at surgical fixation of rib fractures in a well-organized, prospective, randomized, controlled trial.”

The study involved 207 patients, recruited from 15 sites across Canada and the United States from 2011 to 2018. All participants were aged 16 to 85 years with flail chest (≥3 consecutive, segmental, displaced rib fractures) or severe deformity of the chest wall. Exclusion criteria were severe pulmonary contusion, severe head trauma, randomization more than 72 hours after injury, inability to perform surgical fixation within 96 hours from injury, fractures of the floating ribs, or fractures adjacent to the spine not amenable to surgical fixation. Patients were seen for follow-up in one year.

The primary outcome was VFDs in the first 28 days following injury. Secondary outcomes were days in the ICU, pneumonia, sepsis, need for tracheostomy, mortality, and surgical complications.

Of the enrolled patients, 99 were randomized to nonsurgical treatment, and 108 were randomized to surgical fixation. Mean age was 53 years, 75 percent of patients were male, and mean number of rib fractures was 10.

Mean VFDs were 22.7 for the surgical group and 20.6 for the nonsurgical group, with a mean difference of 2.1 days between the two groups (P = 0.089). Mortality was significantly higher in the nonsurgical group: 6 percent versus zero in the surgical group (P = 0.011). No difference was seen between the two groups with regard to complications or length of ICU or hospital stay. A prespecified subgroup analysis of patients who were intubated and mechanically ventilated at the time of randomization demonstrated a mean difference of 2.8 VFDs in favor of surgery (P = 0.04), as well as a shorter total hospital stay.

Dr. Dehghan noted she was surprised to find that surgery did not affect complications such as pneumonia, ventilator-associated pneumonia, sepsis, or length of ICU stay. “Several retrospective studies report reduced risk of these complications with surgical treatment,” she said. “However, our study did not demonstrate this. It is possible that the modern nonoperative treatment strategies are superior to what was used in prior studies, affecting the results.”

Overall, these study findings demonstrate that patients who are not on mechanical ventilation do not benefit from surgical fixation over nonoperative treatment, Dr. Dehghan summarized. “Their outcomes are much better than the subset of patients who require mechanical ventilation,” she said. “However, in patients who require mechanical ventilation, surgery has the potential to decrease time on mechanical ventilation and reduce length of stay. Patients in the surgical group also had a lower rate of mortality, although it is difficult to know if this is because of surgery or potentially due to chance alone.”

Dr. Dehghan noted that appropriate patient selection is important in this setting.

“If the patient has minimal displacement of ribs or is comfortable, able to take deep breaths, and able to cough, then surgery will probably not be beneficial,” she said. “Patients who benefit the most are those on mechanical ventilation and who have gross disruption of their ribs and chest wall.”

Limitations are that the study was powered to look at all patients, intubated and non-intubated, Dr. Dehghan said.

“It was not powered for the subgroup analysis or secondary outcomes (such as mortality), and the results of these analyses should be regarded with caution,” she said.

Dr. Dehghan’s coauthors of PO487, “Operative vs. Nonsurgical Treatment of Acute Unstable Chest Wall Injuries: A Multicenter Randomized Controlled Trial,” were Aaron Nauth, MD, MSc; Emil H. Schemitsch, MD, FRCSC; Milena Vicente, RN; Richard Jenkinson, MD, MSc, FRCSC; Hans J. Kreder, MD, MPH, FRCSC; Michael D. McKee, MD; the Canadian Orthopaedic Trauma Society; and the Unstable Chest Wall RCT Study Investigators.

Terry Stanton is the senior medical writer for AAOS Now. He can be reached at tstanton@aaos.org.