Study reveals no significant differences in outcome between IM nails and plate fixation in Medicare population

Intramedullary (IM) nails are becoming increasingly more popular than plate fixation for treatment of intertrochanteric hip fractures. Despite surgeon preference, however, study data presented at the Orthopaedic Trauma Association annual meeting suggest that in older patients, improvement in outcomes for IM nail fixation is limited compared with plate fixation.

Researchers from the University of Louisville (Ky.) evaluated the temporal trends in treatment patterns for intertrochanteric hip fractures using IM nails and plate fixation and compared the postoperative complication and mortality risks associated with each procedure.

Their analysis of the National Medicare 5 Percent Sample claims database found that the proportion of patients with intertrochanteric hip fractures who were treated with IM nailing increased from 3.3 percent in 1998 to 63.1 percent in 2007.

The researchers also uncovered another trend.

“We discovered that, from 1998 to 2007, the incidence of intertrochanteric hip fractures declined by approximately 20 percent,” said presenter Craig S. Roberts, MD, MBA.

“We had anticipated finding an epidemic of hip fractures, but the data show the contrary,” added lead author Arthur L. Malkani, MD. “We believe the reason for the decline is multifactorial, but is due in large part to the increased awareness and medical treatment of osteoporosis.”

Study methods
The researchers identified 9,157 IM nail procedures and 27,687 plate fixation procedures and compared postoperative complication and mortality data within 90 days and 1 year for each procedure. Complications evaluated within 90 days of surgery included deep venous thrombosis (DVT); infection; pulmonary embolism (PE); and mechanical, neurologic, and cardiac complications. Incidences of death, malunion/nonunion, conversion to hip replacement, and reoperation with subsequent internal fixation were evaluated for up to 1 year post surgery.

Evaluating the results
Based on the 1998–2007 data, IM nail patients had a higher adjusted risk of PE at 90 days (+39 percent; p = 0.003) and a higher adjusted risk of mortality at 1 year (+9 percent; p < 0.001) compared with plate fixation patients. IM nail patients, however, had a lower adjusted risk of conversion to hip replacement at 1 year (–22 percent; p = 0.054). Both treatment groups showed relatively high incidences of short-term DVT (Table 1).

The researchers also assessed the risk factors for complications and mortality, which were determined using regression analysis. In general, they found that elderly, sicker, and male patients were at higher risk of mortality at 1 year, regardless of the type of fixation used.

“The incidence of mortality at 1 year was concerning,” said Dr. Malkani. “We believe it relates to the underlying medical status of the hip-fracture patient and the number of comorbidities.”

To identify possible early adopter or learning curve phenomena in the use of IM nails, the researchers performed a subgroup analysis of 2006–2007 Medicare data. The subgroup cohorts included 4,074 IM-nail patients and 2,869 plate-fixation patients.

The lower adjusted risk of conversion to hip replacement at up to 1 year was still observed for IM-nail patients (–36 percent; p = 0.037). No other significant differences were found. DVT (4 percent) and mortality (25 percent) were the most frequently reported 90-day and 1-year complications, respectively, in both treatment groups.

Conclusions
Based on their overall and subgroup analyses, the researchers concluded that complication rates are comparable between the two treatment groups and that risk factors—including age, gender, race, comorbidity, year of procedure, socioeconomic status, and inpatient and outpatient service—can vary by procedure and follow-up duration.

Future studies on the subject, according to Dr. Roberts, would ideally include longer follow-up, examination of cost effectiveness, and analysis of the causes of death. “At this time, however, our data do not support recommending using one implant over another,” he said.

“We found no major differences in outcomes between the use of IM nails and compression plate hip screw fixation of intertrochanteric hip fractures that justify the dramatic increase in the use of IM nails and a corresponding decline in the use of plates for the treatment of these fractures,” added Dr. Malkani.

Drs. Malkani’s and Roberts’ coauthors of “Risk of Complications Following Treatment of Intertrochanteric Hip Fractures with Intramedullary Nail and Plate Fixation in the Medicare Population,” include Colin Carroll; David Seligson, MD; Edmund Lau, PhD; Steven Kurtz, PhD; and Kevin Ong, PhD.

Disclosure information: Dr. Malkani—Stryker, Synthes; Dr. Roberts—Synthes, Skeletal Trauma; Dr. Seligson—Stryker; the other authors reported no conflicts.

Maureen Leahy is assistant managing editor of AAOS Now. She can be reached at leahy@aaos.org

Bottom Line

• Intertrochanteric hip fracture rates are declining in the Medicare population, but the proportion of these fractures treated with IM nails is increasing.
• DVT, infection, mechanical, neurological, and cardiac complication rates for IM nails and plate fixation are comparable.
• IM-nail patients have a lower adjusted risk of conversion to hip replacement at up to 1 year post surgery.
• The relatively high incidences of DVT and PE associated with both IM nails and plate fixation in treating these fractures underscore the need for prophylactic treatment of these conditions in the Medicare population.