This retrospective study from Mayo Clinic analyzed 27,004 primary THAs to identify risk factors for and prognosis of motor nerve palsy. Forty-seven patients (0.17%) developed a clinically relevant motor nerve palsy. The study defined risk factors and quantified recovery rates with a minimum 2-year follow-up.
The prevailing assumption before this paper was that incomplete palsies carried a favorable prognosis. Farrell et al. Directly challenged this — showing that the majority of nerve injuries after THA, complete or incomplete, never fully resolved.
When consenting a patient with DDH or posttraumatic arthritis for primary THA, explicitly discuss nerve palsy risk. These diagnoses carry odds ratios above 3.5, and the patient deserves to know that if palsy occurs, full recovery is the exception, not the rule.
If a patient wakes from THA with acute sciatic loss and the limb has been lengthened, return to the OR promptly. Exchange the modular head to shorten the limb. If hematoma is suspected as the cause of a progressive sciatic palsy, early decompression is warranted and can yield full recovery.
Obtain electromyography at 8-12 weeks in any patient with no neurologic recovery. It confirms the injury level and helps frame prognosis in the counseling conversation.
This retrospective study from Mayo Clinic analyzed 27,004 primary THAs to identify risk factors for and prognosis of motor nerve palsy. Forty-seven patients (0.17%) developed a clinically relevant motor nerve palsy. The study defined risk factors and quantified recovery rates with a minimum 2-year follow-up.
The prevailing assumption before this paper was that incomplete palsies carried a favorable prognosis. Farrell et al. Directly challenged this — showing that the majority of nerve injuries after THA, complete or incomplete, never fully resolved.
When consenting a patient with DDH or posttraumatic arthritis for primary THA, explicitly discuss nerve palsy risk. These diagnoses carry odds ratios above 3.5, and the patient deserves to know that if palsy occurs, full recovery is the exception, not the rule.
If a patient wakes from THA with acute sciatic loss and the limb has been lengthened, return to the OR promptly. Exchange the modular head to shorten the limb. If hematoma is suspected as the cause of a progressive sciatic palsy, early decompression is warranted and can yield full recovery.
Obtain electromyography at 8-12 weeks in any patient with no neurologic recovery. It confirms the injury level and helps frame prognosis in the counseling conversation.