Session VII - Tibia

Tibia Fractures: A Patient-Based Decision Analysis

Paul Tornetta, III, MD; Timothy Bhattacharyya, MD; Jonathan Kuo, MD; Boston University Medical Center, Boston, Massachusetts, USA

Purpose: We analyzed patients' perceived outcomes from functional bracing and intramedullary nailing for tibial shaft fractures with use of the statistical method of decision analysis.

Background: The best treatment for tibial shaft fractures is debated. Functional bracing provides a high union rate but has a higher malunion rate, and there is a longer time to full weightbearing. Intramedullary nailing provides faster healing and a lower nonunion rate but carries attendant risks of surgery and knee pain. The statistical method of decision analysis allows judgments to be made based on reported complication rates. It can determine the "utility" of each treatment, including known potential complications.

Methods: The literature on functional bracing and tibial nailing was reviewed to determine the probabilities of union with proper alignment, delayed union, malunion, nonunion, infection, and other complications. The utilities of ten possible outcomes (for example, union with brace, union with tibial nail, nonunion with brace, etc.) were determined by surveying a cohort of healthy people recruited from the community. The survey used lay language and pictures to explain tibia fractures, outline the treatment options, and describe the possible outcomes. To avoid survey bias, half of the surveys presented surgery as the first option and half presented bracing first. Utilities were measured by the direct rating method on a 100-point scale (100 being the best score). Decision analysis was then performed with use of Excel software, and statistical analysis was performed with SPSS 10.0.

Results: Patients assigned equally high utilities to union achieved by functional bracing and intramedullary nailing, despite the faster healing time of surgical treatment (P = 0.16; power = 98%). Patients assigned a low utility to the outcome of union with knee pain after tibial nailing (average 44 points). Union with knee pain had a lower utility than that of nonunion requiring secondary surgery. Nonunion after nailing had a lower utility than that of nonunion after functional bracing (57 vs. 51 points, P<0.003). Combining the probabilities of complications for each method with the patient-assigned utilities, decision analysis concluded that 84% of patients would best be served by functional bracing. Even if the worst reported values for the rates of union, malunion, and nonunion for bracing were used (sensitivity analysis), functional bracing remained the treatment of
choice for 81% of patients. Only when the rate of knee pain was decreased to 12% or less did intramedullary nailing become the treatment of choice.

Conclusions: Patients' perceived utility of treatment options did not rely on time to union. Surgery for nonunion was perceived to be worse if surgery was the original treatment. Knee pain and was the most critical factor in decision making for this sample cohort. Surgeons should specifically address the incidence of persistent knee pain with their patients when functional treatment and nailing are both considered options for a particular shaft fracture.