Attending Physician St. Charles Hospital/CHSLI Port Jefferson, New York, United States
Case Diagnosis: 63 year old Male with history of recent right total hip arthroplasty, right medial meniscectomy who presented to the ED with intense pain in the right hip after standing from chair. On presentation, patient unable to bear weight and had profound weakness in the right leg. Initially had no associated paresthesia. Patient had a R THA done two weeks prior and was recently discharged from acute rehabilitation. CT imaging demonstrated right prosthetic hip dislocation which resulted in sciatic nerve palsy.
Case Description: On discharge to acute rehabilitation, patient had continued weakness in his right foot and donned a Bledsoe brace. Muscle strength for RLE dorsiflexion 0/5 and plantarflexion 1/5. Patient had limited ambulation, developed paresthesia, and had an antalgic gait with decreased foot clearance. During the rehabilitation course, therapy focused on functional mobility, gait training, transfer training and education on hip precautions. Pain was controlled with a combination of acetaminophen/roxicodone, muscle spasms improved with tizanidine. Patient had functional improvement in RLE during rehabilitation course, improvement in sensory deficits, increased endurance and was fitted with AFO.
Discussions: The sciatic nerve is the most commonly injured nerve in posterior hip dislocations with innervation to the biceps femoris, semitendinosus, semimembranosus, and adductor magnus. The overall prevalence of nerve palsy following a hip replacement is 1% with the sciatic nerve being most common. The occurrence of sciatic nerve palsy after a THA is even more scarce (< 0.1%). Recovery can take on average 21 months based severity of entrapment.
Conclusions: Prosthetic hip dislocations leading to sciatic nerve palsy is a rare occurrence with an overall low prevalence rate. Functional recovery is based on severity of nerve compression and the time it takes to decompress the nerve. Rehabilitation plays a vital role in improving functional recovery with primary focus on muscle strengthening, gait training, and awareness/education of hip precautions.