summary THA Sciatic Nerve Palsy is an uncommon, but potentially devastating complication following THA that may lead to persistent foot drop. Diagnosis can be made clinically with post-operative complaints of numbness and paresthesias along the sciatic nerve distribution and weakness of the dorsiflexors of the foot. Treatment is placing the hip in extension and knee in flexion immediately post-operatively. Observation and AFO in the presence of foot drop are recommended to monitor for recovery of the nerve. epidemiology Incidence uncommon (0-3%) most common cause for medical malpractice litigation following THA Anatomic location peroneal division of sciatic nerve most commonly affected (80%) sciatic nerve travels closest to acetabulum at level of ischium exercise care with posterior acetabular retraction when hip in flexed position less commonly affected nerves include femoral obturator superior gluteal Etiology Causes direct trauma stretch compression due to hematoma heat from polymethylmethacralate polymerization unrecognized lumbar lateral recess stenosis unknown (40%) Risk factors for motor nerve palsies include developmental dysplasia of the hip revision surgery female gender limb lengthening posttraumatic arthritis surgeon self-rated procedure as difficult pre-existing lumbar stenosis Presentation Post-operative complaints of numbness, paresthesias, or weakness Imaging Post-operative CT may be helpful if hematoma suspected Ultrasound may be helpful if hematoma suspected Studies EMGs may be used post-operatively to confirm level of injury and guide discussion with patient regarding prognosis Treatment Intraoperative adult hip dysplasia undergoing THA subtrochanteric osteotomy downsizing components Immediate postoperative place hip in extension and knee in flexion indications immediate post-operative palsy technique decreases tension along sciatic nerve immediate evacuation in operating room indications post-operative hematoma Persistent foot drop AFO orthosis indications first line of treatment for persistent foot drop Prognosis Only 35% to 40% recover full strength after complete palsy
QUESTIONS 1 of 17 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Previous Next Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (SBQ16HK.11) A 65-year-old woman undergoes an uncomplicated right total hip arthroplasty as seen in Figure A. Preoperatively her right leg length was 2mm shorter than the left side. On the evening of surgery she has full motor strength and intact sensation. On the morning of postoperative day two she develops an inability to dorsiflex her ankle. There is no wound drainage and her anticoagulation levels are within normal limits. What is the next best step in treatment? QID: 211229 FIGURES: A Type & Select Correct Answer 1 Maintain head of the bed flat with non-weight bearing restrictions 1% (10/1479) 2 Obtain an EMG 2% (35/1479) 3 Radiograph of the knee 2% (23/1479) 4 Place the hip in flexion and the knee in extension 3% (38/1479) 5 Place the hip in extension and the knee in flexion 92% (1366/1479) L 1 Question Complexity A Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 5 Review Tested Concept Review Full Topic (OBQ13.231) Immediately following a total hip arthroplasty (THA), a healthy 55-year-old patient is unable to dorsiflex her ankle or extend her great toe. After 4 weeks she continues to ambulate with a "slapping gait." Examination reveals passive ankle joint dorsiflexion to 10 degrees. What is the most appropriate next treatment option? QID: 4866 FIGURES: A B Type & Select Correct Answer 1 MRI of her spine and pelvis 3% (137/4360) 2 Revision total hip arthroplasty 4% (177/4360) 3 Ankle-foot orthosis 89% (3859/4360) 4 Posterior tibial tendon transfer to navicular bone 2% (84/4360) 5 Neurology consult 2% (81/4360) L 1 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review Tested Concept Review Full Topic (OBQ13.30) After total hip arthroplasty (THA) for osteoarthritis a patient is unable to dorsiflex her ankle or extend her great toe. She is treated conservatively with an orthosis and after 3 months on physical therapy she ambulates with a "slapping gait." What is the most appropriate next treatment option? QID: 4665 Type & Select Correct Answer 1 MRI of her spine 7% (384/5770) 2 Ankle Fusion 1% (60/5770) 3 Continue Ankle-Foot Orthosis 87% (5037/5770) 4 Revision total hip arthroplasty 1% (56/5770) 5 Sural nerve grafting 4% (204/5770) L 1 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review Tested Concept Review Full Topic (OBQ12.164) A 45-year-old man has had the gait disturbance shown in Video A ever since a total hip replacement two years ago. Since then he has undergone physical therapy and nerve exploration without any clinical improvement. Extensive AFO bracing was attempted but was not tolerated by the patient. A recent ankle radiograph is shown in Figure A. The Silfverskiold test reveals dorsiflexion of 20 degrees with knee flexion, and 10 degrees with full knee extension. The results of muscle testing using a Cybex dynamometer are shown in Figure B. What is the most appropriate next step in in treatment. QID: 4524 FIGURES: V A B Type & Select Correct Answer 1 Ankle arthrodesis in 30 degrees of dorsiflexion 1% (43/4096) 2 Posterior tibial tendon transfer to the lateral cuneiform through the interosseous membrane 73% (3009/4096) 3 Split anterior tibial tendon transfer to the cuboid 3% (131/4096) 4 Peroneus longus transfer to the navicular and gastrocnemius recession 7% (290/4096) 5 Flexor hallucis transfer to the navicular and tendo Achilles lengthening (TAL) 15% (595/4096) L 2 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review Tested Concept Review Full Topic (OBQ11.208) A 65-year-old female with a history of developmental dysplasia of the hip (DDH) undergoes a total hip arthroplasty (THA) utlizing a posterior approach. Following THA, she notices an inability to dorsiflex the ankle of her operative extremity. Her pre-operative and post-operative radiographs are seen in figues A and B. Which of the following intra-operative techniques could have avoided this complication in this patient? QID: 3631 FIGURES: A B Type & Select Correct Answer 1 Utilization of an anterior approach 4% (155/4381) 2 Modular components 1% (49/4381) 3 Use of a larger femoral head 1% (24/4381) 4 Femoral shortening osteotomy 93% (4096/4381) 5 Acetabular osteotomy 1% (48/4381) L 1 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review Tested Concept Review Full Topic Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (SBQ10HK.20.1) A 60 year-old man with a history of atrial fibrillation and a mechanical aortic valve replacement undergoes total hip athroplasty via a posterior approach. Post-operatively, at the recommendation of his cardiology team, he is restarted on warfarin. Four days after discharge, the patient returns to the emergency department with a 10% drop in hematocrit (now 20%) and a new complete sciatic nerve palsy. His INR is 6 and his dressing is saturated. What is the best course of action? QID: 210734 Type & Select Correct Answer 1 Reversal of INR, application of incisional wound vac, clinical monitoring of nerve palsy 14% (224/1598) 2 Transfusion to raise the hematocrit to 30%, sequential neurovascular examinations 3% (43/1598) 3 Reversal of INR, urgent surgical irrigation and debridement 57% (912/1598) 4 Hold warfarin and transition to enoxaparin, application of incisional wound vac, sequential neurovascular examinations 10% (153/1598) 5 Reversal of INR, placement of a temporary vena cava filter, exploration of the sciatic nerve 16% (253/1598) L 3 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review Tested Concept Review Full Topic Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ09.155) A 67-year-old woman undergoes a total hip arthroplasty. Postoperatively, she develops a complete peroneal palsy that does not improve with flexion of the knee and removal of compressive dressings. All of the following are associated with a post-operative nerve palsy EXCEPT: QID: 2968 Type & Select Correct Answer 1 Developmental dysplasia of the hip 2% (36/2394) 2 Lengthening of the extremity 0% (7/2394) 3 Surgeon self-rating the procedure as being a difficult intervention 11% (259/2394) 4 Avascular necrosis of the femoral head 63% (1516/2394) 5 Posttraumatic arthritis 24% (565/2394) L 3 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review Tested Concept Review Full Topic (OBQ08.267) Risk factors for a motor nerve palsy following primary total hip arthroplasty include all of the following EXCEPT? QID: 653 Type & Select Correct Answer 1 Developmental dysplasia of the hip 3% (40/1536) 2 Limb lengthening 1% (13/1536) 3 Posttraumatic arthritis 27% (409/1536) 4 Obesity 45% (685/1536) 5 Posterior approach 25% (382/1536) L 4 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review Tested Concept Review Full Topic (OBQ08.224) What percentage of patients with complete peroneal nerve palsy after total hip arthroplasty will never recover full strength? QID: 610 Type & Select Correct Answer 1 90% to 95% 7% (137/1907) 2 60% to 65% 43% (828/1907) 3 40% to 45% 18% (339/1907) 4 20% to 25% 23% (448/1907) 5 0% to 5% 8% (146/1907) L 4 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review Tested Concept Review Full Topic This is an AAOS Self Assessment Exam (SAE) question. Orthobullets was not involved in the editorial process and does not have the ability to alter the question. If you prefer to hide SAE questions, simply turn them off in your Learning Goals. (SAE07HK.89) Which of the following factors increases the risk of sciatic nerve injury in primary total hip arthroplasty (THA)? QID: 6049 Type & Select Correct Answer 1 Male gender 2% (7/374) 2 Anterolateral approach 1% (5/374) 3 Posterior superior quadrant acetabular screw placement 17% (62/374) 4 Osteonecrosis 1% (2/374) 5 Developmental dysplasia of the hip 79% (296/374) L 1 Question Complexity E Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 5 Review Tested Concept Review Full Topic (OBQ07.110) All of the following are risk factors for developing a sciatic nerve palsy following total hip arthroplasty EXCEPT: QID: 771 Type & Select Correct Answer 1 Female gender 39% (1014/2575) 2 Developmental dysplasia of the hip 1% (37/2575) 3 Revision surgery 1% (21/2575) 4 Rheumatoid arthritis 58% (1490/2575) 5 Lengthening of the extremity 0% (6/2575) L 3 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review Tested Concept Review Full Topic (OBQ04.142) Figures A and B are pre-operative and intra-operative radiographs of a 67-year-old male that has undergone a left total hip arthroplasty under general anesthesia. The patient had no motor deficits pre-operatively. During the operation, the trial acetabular and femoral components were positioned and reduced with no complication. Intra-operative leg lengths were equal. Before implanting the real components, the surgeon and anaesthesiologist performed a wake up test, which revealed that the patient was unable to dorsiflex the left foot. What would be the most appropriate next step in the management of this patient? QID: 1247 FIGURES: A B Type & Select Correct Answer 1 Urgent electromyogram and nerve conduction study 3% (92/2774) 2 Continue with sized trial components and observe the motor function in surgical recovery area 19% (540/2774) 3 Remove all implants and insertion of cement spacer 5% (128/2774) 4 Perform a shortening subtrochanteric osteotomy 72% (1989/2774) 5 Urgent neurology consult 0% (5/2774) L 3 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review Tested Concept Review Full Topic (OBQ04.249) During revision total hip arthroplasty (THA), adjunctive motor-evoked potentials (MEPs) and electromyography (EMG) are utilized to monitor the sciatic and peroneal nerves. During the procedure, a conduction abnormality arises in the sciatic nerve. Which of the following actions would decrease tension on the sciatic nerve? QID: 1354 Type & Select Correct Answer 1 Provide traction to the leg 0% (5/2843) 2 Pulsatile irrigation in the wound to remove blood clots 0% (3/2843) 3 Flex the hip 6% (158/2843) 4 Extend the hip 94% (2660/2843) 5 Extend the knee 0% (6/2843) L 1 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review Tested Concept Review Full Topic