Recovery after neurologic injury in operative acetabular and pelvic fractures: Defining the natural history of foot drop.

Introduction: Dorsiflexion weakness, or footdrop, is a well-described sequela of high-energy acetabular and pelvic trauma, but little data exists describing the factors related to neurologic recovery and the timeline therein. An improved understanding of these factors would facilitate prognostication, patient education, and treatment decision-making. The aim of this study was to compare neurologic recovery between acetabular and pelvic fractures, delineate factors associated with recovery, and determine the expected timeline of recovery.

Methods: A retrospective chart review was conducted at a level 1 tertiary referral center from 2000 to 2021 using CPT codes and keyword search functions to identify adult patients with neurologic injury in the setting of operative acetabular and/or pelvic ring trauma. Patients were included if they had documented, graded weakness not clearly explained by a concomitant injury (extremity or spine) following a pelvic/acetabular injury. Patients were followed to a minimum of 6 months follow-up or to neurologic recovery. Primary outcomes were the presence of motor recovery and time to initial and maximum recovery. The contributions of injury type and initial neurologic status were analyzed using logistic regression for impact on neurologic recovery.

Results: We identified 121 patients with neurologic injury and resultant footdrop in the setting of an operative pelvic ring or acetabular fracture. From this cohort, 58 patients (47.9 %) demonstrated some degree of neurologic recovery in follow-up. There was no difference in recovery when comparing injury type (pelvis vs. acetabulum). Any motor function (including flicker) at time of initial evaluation was predictive of recovery (OR 6.18, [2.00 - 19.14]; p = 0.002). Initial neurologic function also correlated with more rapid recovery in comparison to patients with initial absent neurologic function both in time to initial recovery (56 days vs 107 days; p = 0.016) and time to maximum recovery (153 days vs 241 days; p = 0.027).

Conclusions: These results highlight the relatively poor prognosis for neurologic recovery in operative pelvic and acetabular injuries. Any initial neurologic function is predictive of likelihood of neurologic recovery and correlates with a more expedient neurologic recovery. Ultimately, this enables providers to better educate patients and facilitates decisions regarding further intervention.