Sat., 10/6/12 Tibial Fractures, PAPER #114, 4:03 pm OTA-2012
Character, Incidence, and Predictors of Knee Pain and Activity After Intramedullary Nailing of an Isolated Tibia Fracture
William T. Obremskey, MD, MPH1; Julie Agel, ATC2; Kristin Archer, PhD1;
Paul Tornetta III, MD3; for the SPRINT (Study to Prospectively evaluate Reamed
Intramedullary Nails in Tibial fractures) Investigators;
1Vanderbilt University Medical Center, Nashville, Tennessee, USA;
2Harborview Medical Center, Seattle, Washington, USA;
3Boston Medical Center, Boston, Massachusetts, USA
Purpose: Knee pain is the most common complication following intramedullary nailing of the tibia with the incidence of knee pain reported to vary from 49% to 69%. The primary purpose of the study is to describe the incidence and predictors of knee pain in the large cohort of patients enrolled in the SPRINT (reamed vs unreamed intramedullary nails [IMNs]) study. A secondary goal is to compare impact on common activities of patients after an isolated tibia fracture.
Methods: The study included 437 patients from 30 sites who had an isolated tibia fracture treated with an IMN. 393 and 428 patients completed 6-month and 12-month assessments on pain, respectively. Self-reported activity at 12 months was completed by 390 patients for stairs outcome, 387 for kneel outcome, and 385 for run and walk prolonged outcomes. Self-reported activity at 12 months was completed by 390 patients for stairs outcome, 387 for kneel outcome, and 385 for run and walk prolonged outcomes. In addition to standard demographic information (age, sex, race, smoking status), injury characteristics (fracture location, wound type, fasciotomy, injury type, AO classification) and surgical technique (tendon approach, entry portal, nail type, and 2+ locking screws) were recorded. Knee pain was defined on a scale from 1 to 7, with 1 being “no pain” and 7 being a “very great deal of pain.” Knee pain >4 was considered clinically significant. Patients reported if they were “able,” “able with difficulty,” or “unable” to perform the following activities: stairs, kneel, run, walk prolonged. Variables that were significant in univariate analyses and a priori variables were tested in multivariable mixed-model regression analyses that included a random effect to control for the clustering of patients by site.
Results: 437 patients had a mean age of 41.9 years (standard deviation, 15.6); 71% were male. 76% were closed injuries and 9 (2%) had a fasciotomy. There were 19% midshaft, 8% proximal, and 73% distal fractures. The paratendinous approach was used in 77% of cases and a superior portal was used 75% of the time. Knee pain: Reaming did not influence knee pain so the remainder of the evaluations were performed across these groups. The percent of patients with a “good” to a “very great” deal of pain (>4) was 13% at 6 months and 11% at 12 months. 45% and 51% of patients reported “no” or “very little” pain at 6 and 12 months, respectively. At 12 months, smoking was the only risk factor for increased knee pain (β = 0.48; P <0.001). Activity at 12 months: 45% and 26% of patients were “able with difficulty” or “unable” to kneel, respectively. For run, 37% of patients were “able with difficulty” and 29% were “unable.” The percent of patients who said they were “able with difficulty” or “unable” to climb stairs was 35% and walk prolonged was 31%. Female sex (odds ratio [OR] = 1.1; P = 0.01) was a significant predictor of being unable to kneel at 12 months. Older age (OR = 1.01; P <0.001) and having a fasciotomy (OR = 1.6; P = 0.002) were significant predictors of being unable to run. Risk factors for “able with difficulty” or “unable to perform” stairs and walk prolonged at 12 months were: stairs: older age (OR = 1.01; P = 0.001), smoking (OR = 1.1; P = 0.01), proximal fracture (OR = 1.2; P = 0.04), and superior portal (OR = 1.1, P = 0.02); walk prolonged: older age (OR = 1.01; P = 0.001), smoking (OR = 1.2; P = 0.001), and open fracture (OR = 1.2, P = 0.003).
Conclusion: Clinically significant knee pain (>4 of 7) was present in 11% of patients 1 year after an isolated tibia fracture. An open fracture, fasciotomy, fracture location, and surgical technique did not predict pain at 12-month follow-up. Patient smoking was the most consistent factor that predicted knee pain. 26% to 45% of patients had difficulty performing or were unable to perform routine daily activities of kneeling, running, stair-climbing, or walking prolonged distances.
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• The FDA has not cleared this drug and/or medical device for the use described in this presentation (i.e., the drug or medical device is being discussed for an “off label” use). ◆FDA information not available at time of printing. Δ OTA Grant.