Orthopaedic trauma clinical research: is 2-year follow-up necessary? Results from a longitudinal study of severe lower extremity trauma.

BACKGROUND: The ideal length of follow-up for orthopedic trauma research studies is unknown. This study compares 1- and 2-year complications, clinical recovery, and functional outcomes from a large prospective clinical study.
METHODS: Patients (n = 336) with limb threatening unilateral lower extremity injuries were followed at the 12, 24, and 84 months. Major outcomes observed were complications requiring hospital re-admission, fracture and wound healing, attainment of full weight bearing status, return to work, and self-reported functional outcome using the Sickness Impact Profile.
RESULTS: The rate of newly observed complications beyond year 1 was small, ranging from 0 to <2%. In addition, 85% to 90% of the clinical recovery outcomes were attained by 1 year, and patients not achieving clinical recovery during the first year had significantly worse functional outcomes. Only 5% of patients returned to work between 1 year and 2 years. Although, a substantial number of patients achieved functional recovery between 1 year and 2 years, of the patients not achieving functional recovery at year 1, 85% of those who would go on to achieve functional recovery during the second year could be predicted using year 1 data.
CONCLUSIONS: Although long-term follow-up provides a more complete picture of final outcomes and rate of recovery, follow-up beyond 1 year is difficult and expensive. In our study, it accounted for 20% of the total cost. The analysis of our data suggests that 1-year data were sufficient to address our major study hypotheses.