Associations of musculoskeletal dysfunction, time to brake, and patient reported outcomes following lower extremity trauma

Introduction: Inability to drive a motor vehicle due to lower extremity injury is a major inconvenience. Timing of safe return to driving has not been much studied. Objective measurements such as time to brake (TTB) have been proposed; however, utility and concordance of functional outcome measurements have not been previously evaluated. The purpose of this project is to measure these parameters and to assess for associations with ability to safely return to driving, improving the ability of clinicians to assess for measurements of driving readiness without specifically measuring TTB. Methods: A prospective, cohort study of 232 patients with complex lower extremity injuries to the pelvis, acetabulum, hip, femur, knee, tibia, ankle, and foot was performed. Time to brake (TTB) was measured once weightbearing was allowed. Function was assessed by the Musculoskeletal Function Assessment (MFA) questionnaire, and pain, mobility, and physical functions, via patient reported outcome measurement information system (PROMIS) surveys. Results: Patients with longer TTB had significantly elevated MFA scores indicating increased musculoskeletal dysfunction post-injury. As the MFA score increased by 1 point, TTB increased by 0.013 s (p<0.001). PROMIS metrics were also significantly associated with patients experiencing more pain and worse mobility as TTB increased. Discussion: Many patients continue to exhibit musculoskeletal dysfunction several months post-treatment for complex lower extremity injuries. Patients with better PROMIS metrics and MFA scores, and shorter TTB are more appropriate to return to driving. Surgeons may be better informed about safe driving ability by considering these measurements.