Introduction Introduction epidemiology uncommon (0-3%), but potentially devastating complication following THA 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 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 prognosis only 35% to 40% recover full strength after complete palsy 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
QUESTIONS 1 of 14 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Previous Next Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (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? Tested Concept QID: 4866 FIGURES: A B Type & Select Correct Answer 1 MRI of her spine and pelvis 3% (114/4122) 2 Revision total hip arthroplasty 4% (159/4122) 3 Ankle-foot orthosis 89% (3671/4122) 4 Posterior tibial tendon transfer to navicular bone 2% (80/4122) 5 Neurology consult 2% (77/4122) L 1 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review tested concept (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? Tested Concept QID: 4665 Type & Select Correct Answer 1 MRI of her spine 6% (352/5460) 2 Ankle Fusion 1% (54/5460) 3 Continue Ankle-Foot Orthosis 88% (4785/5460) 4 Revision total hip arthroplasty 1% (54/5460) 5 Sural nerve grafting 3% (187/5460) L 1 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review tested concept (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? Tested Concept QID: 3631 FIGURES: A B Type & Select Correct Answer 1 Utilization of an anterior approach 3% (147/4222) 2 Modular components 1% (43/4222) 3 Use of a larger femoral head 1% (24/4222) 4 Femoral shortening osteotomy 94% (3955/4222) 5 Acetabular osteotomy 1% (45/4222) L 1 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review tested concept Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK 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: Tested Concept QID: 2968 Type & Select Correct Answer 1 Developmental dysplasia of the hip 1% (31/2267) 2 Lengthening of the extremity 0% (6/2267) 3 Surgeon self-rating the procedure as being a difficult intervention 10% (231/2267) 4 Avascular necrosis of the femoral head 64% (1448/2267) 5 Posttraumatic arthritis 24% (540/2267) L 3 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review tested concept (OBQ08.267) Risk factors for a motor nerve palsy following primary total hip arthroplasty include all of the following EXCEPT? Tested Concept QID: 653 Type & Select Correct Answer 1 Developmental dysplasia of the hip 3% (37/1348) 2 Limb lengthening 1% (11/1348) 3 Posttraumatic arthritis 26% (350/1348) 4 Obesity 44% (598/1348) 5 Posterior approach 26% (346/1348) L 4 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review tested concept (OBQ08.224) What percentage of patients with complete peroneal nerve palsy after total hip arthroplasty will never recover full strength? Tested Concept QID: 610 Type & Select Correct Answer 1 90% to 95% 7% (125/1735) 2 60% to 65% 44% (756/1735) 3 40% to 45% 18% (312/1735) 4 20% to 25% 23% (396/1735) 5 0% to 5% 8% (137/1735) L 4 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review tested concept 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)? Tested Concept QID: 6049 Type & Select Correct Answer 1 Male gender 2% (5/243) 2 Anterolateral approach 1% (2/243) 3 Posterior superior quadrant acetabular screw placement 18% (44/243) 4 Osteonecrosis 1% (2/243) 5 Developmental dysplasia of the hip 77% (188/243) L 1 Question Complexity E Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 5 Review tested concept (OBQ07.110) All of the following are risk factors for developing a sciatic nerve palsy following total hip arthroplasty EXCEPT: Tested Concept QID: 771 Type & Select Correct Answer 1 Female gender 39% (937/2416) 2 Developmental dysplasia of the hip 1% (35/2416) 3 Revision surgery 1% (20/2416) 4 Rheumatoid arthritis 58% (1411/2416) 5 Lengthening of the extremity 0% (6/2416) L 3 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review tested concept (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? Tested Concept QID: 1247 FIGURES: A B Type & Select Correct Answer 1 Urgent electromyogram and nerve conduction study 3% (84/2656) 2 Continue with sized trial components and observe the motor function in surgical recovery area 20% (520/2656) 3 Remove all implants and insertion of cement spacer 5% (123/2656) 4 Perform a shortening subtrochanteric osteotomy 72% (1905/2656) 5 Urgent neurology consult 0% (5/2656) L 3 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review tested concept (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? Tested Concept QID: 1354 Type & Select Correct Answer 1 Provide traction to the leg 0% (4/2641) 2 Pulsatile irrigation in the wound to remove blood clots 0% (3/2641) 3 Flex the hip 5% (142/2641) 4 Extend the hip 94% (2476/2641) 5 Extend the knee 0% (5/2641) L 1 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review tested concept