An analysis of gait changes and functional outcome in patients surgically treated for displaced acetabular fractures.

OBJECTIVES: To determine the relationship between gait, muscle strength, and functional outcome in patients who underwent Open Reduction Internal Fixation (ORIF) of a displaced acetabular fracture using an anterior ilioinguinal approach and to compare gait and functional outcome in patients who have undergone ORIF via an anterior approach with a similar group of patients who have undergone ORIF of a displaced acetabular fracture via a posterior approach and a group of able-bodied cohorts and to investigate relationships between gait, strength, and functional outcome within the entire group of patients.
DESIGN: Case series.
SETTING: University Medical Center. PATIENTS: Thirty patients were studied, each with an isolated displaced acetabular fracture who were surgically treated; 15 patients were treated using an anterior ilioinguinal approach, and 15 were treated using a posterior Kocher-Langenbeck approach. MAIN OUTCOME MEASURES: Primary outcome measures included gait analysis (speed and kinematics), hip muscle strength, and functional outcome as assessed with the Musculoskeletal Function Assessment (MFA) questionnaire.
RESULTS: Several of the limb kinematics for the affected and the unaffected limbs was different when patients treated by an anterior surgical approach were compared with those treated from a posterior approach and able-bodied cohorts. Maximum ankle dorsiflexion was greater in the unaffected limb of the anterior group versus the posterior approach group but was equal to the able-bodied cohorts (AB). Both the affected and the unaffected limbs of the anterior group had larger angles for knee flexion at the time of initial contact compared with the posterior group and AB. Both limbs of the anterior group had significantly more knee flexion and less hip rotation than the posterior group but not from AB. There were no differences in trunk inclination between the surgical groups, but the combined group had greater inclination compared with AB. Average MFA score was 17 +/- 12 (range, 0-47) for the anterior group and 22 +/- 17 (range, 0-57) for the posterior group, respectively. MFA scores did not differ significantly based on surgical approach, fracture pattern, or sex. When gait was compared with MFA scores, an inverse relationship was discovered for the group as a whole. That is, worsening function (increased MFA) correlated with decreased kinematics and stride length. Additionally, greater hip strength was associated with additional hip rotation and increased gait speed. A multivariate regression analysis indicated that both hip rotation (which was associated with hip strength) and hip adductor work strength were important predictors of final MFA scores.
CONCLUSIONS: Detailed gait analysis and functional outcome determination indicate that patients treated surgically for a displaced acetabular fracture, either via an anterior or posterior approach, have alterations in their gait, muscle strength, and functional outcome. Maximizing hip muscle strength may improve gait, and improvement in hip muscle strength and gait is likely to improve functional outcome as measured by the MFA. Finally, because both surgical approaches seem to produce the same gait outcomes, it suggests that gait changes after injury and treatment are related to factors other than surgical approach.