The Study to Prospectively Evaluate Reamed Intramedullary [IM] Nails in Tibial Fractures (SPRINT) found virtually no difference between the results achieved with either reamed or nonreamed IM nailing in tibial shaft fractures, according to a presentation given at the 2007 annual meeting of the Orthopaedic Trauma Association (OTA). The study’s primary objective was to assess “the impact of reamed versus nonreamed IM nailing on rates of reoperation at 1 year in patients with open or closed fractures of the tibial shaft.”

SPRINT challenges the results of previous smaller studies, which had encouraged the use of reaming to reduce the risk of nonunion. Investigators in the SPRINT study could not find any data to support assertions that reamed IM nailing was superior to nonreamed nailing.

SPRINT sets new research standard
SPRINT is one of the largest orthopaedic studies ever conducted. “SPRINT raises the bar for all future orthopaedic studies with its comprehensive methodology and strict adherence to protocol. It is the largest study of tibia fractures ever done,” said Timothy Bhattacharyya, MD, who attended the OTA presentation.

“All of the important methodological criteria consorts were in place—multicenter, multinational, blinded, computerized randomization, power analysis. The investigators really established a new standard, a gold standard, in Level 1, prospective, surgical trials,” said Dr. Bhattacharyya.

The study design was developed by primary investigator Mohit Bhandari, MD, in 1997. A few years later, the Canadian Institutes of Health Research (CIHR) underwrote a pilot study, and in 2002, the CIHR and the U.S. National Institutes of Health provided full funding for SPRINT.

Strict protocol followed
The multiyear, multinational study was conducted at 29 clinical sites, with 1,339 patients who were blinded to the treatment method. More than 200 surgeons from three countries—Canada, the Netherlands, and the United States—participated.

To be eligible for inclusion in the study, patients had to be skeletally mature, have either a closed or an open tibial shaft fracture (Gustilo Type I-IIIB), and agree to the insertion of a statically interlocked IM nail. A total of 2,974 patients were screened for the study, and 1,319 patients were randomized into the two groups. The final study included 622 patients who received a reamed IM nail and 604 patients who were given a nonreamed IM nail. Researchers followed the 1,226 patients for 1 year.

A strict protocol was established for all phases of the study, explained Dr. Bhandari. Several measures were taken to ensure objectivity and accuracy.

Patients, outcome assessors, and data analysts were not informed of the treatment method—reamed or nonreamed IM nailing. A novel approach was used to randomize the patients. When a patient met the inclusion criteria for the study, the clinical site called a 24-hour, toll-free “randomization” line to learn which treatment method should be used.

“By having a study that was much larger, multicenter, multinational, with strict criteria for randomization of patients, blinding of surgeons, and independent assessments of outcomes, our results were very different than previous smaller trials,” said Dr. Bhandari.

Standardization helped ensure objectivity
All perisurgical care was standardized, including open-wound care, the use of prophylactic antibiotics, and postsurgical weightbearing.

The most critical standard, according to the researchers, was a prohibition of surgery for at least 6 months following the initial procedure to foster healing. Surgery was allowed only if the patient had bone loss greater than 50 percent. Patients were followed at discharge, at 2 weeks postdischarge, and at 3, 6, 9, and 12 months postsurgery.

All patient notes and radiographs were blinded to the surgeons and hospital staff. The word reamed was deleted from patient notes and radiographs were adjusted so the surgeon could not tell if a reamer had been used. A blinded “central adjudication committee,” consisting of eight orthopaedic surgeons, reviewed all outcomes to ensure absolute objectivity.

Primary outcome measures
Reoperation to promote healing, treat infection, or preserve the limb (fasciotomy for compartment syndrome after nailing) was identified as the primary outcome. “Reoperation was the composite end point; a number of conditions could lead to reoperation, such as bone graft, implant exchange, or dynamization,” said Dr. Bhandari.

“Treating infection or a compartment syndrome were also reasons for reoperation. We found that reamed and unreamed nails had different effects on healing, on infection rates, and on risk of compartment failure,” he continued. In closed fractures, postsurgical compartment syndromes were slightly higher in patients who were treated with reamed nails.

Results show no differences
The rate of reoperation between the two treatment groups was virtually the same—17 percent in the reamed treatment group and 19 percent in the nonreamed group.

Compared with previous studies, the SPRINT study had a lower rate of revisions. Study investigators believe the standardization of care and strict adherence to established protocols resulted in superior care from both surgeons and SPRINT centers. Prohibiting surgery for at least 6 months also contributed to the reduction in revision surgeries.

Dr. Bhandari noted that the “6-month rule” provided an unexpected lesson. “One unique feature of this trial was that we wanted surgeons to simply wait for 6 months. Don’t operate on patients. The most surprising result was the reduction of the overall incidence of reoperation from about 40 percent to 10 percent just by using modern techniques of managing tibial fractures.”

In addition to Dr. Bhandari, the SPRINT steering committee included Gordon Guyatt, MD; Paul Tornetta III, MD; Marc F. Swiontkowski, MD; Emil H. Schemitsch, MD; David W. Sanders, MD; and Stephen Walter, MD.

Annie Hayashi is the senior science writer for AAOS Now. She can be reached at hayashi@aaos.org