Introduction Common causes of LLD congenital disorders hemihypertrophy dysplasias PFFD DDH unilateral clubfoot paralytic disorders spasticity (cerebral palsy) polio physis disruption infection trauma tumor Epidemiology 2cm LLD occurs in up to 2/3 of the population Associated conditions back pain increased prevalence of back pain osteoarthritis decreased coverage of femoral head on long leg side leads to osteoarthritis 84% of the time functional scoliosis inefficient gait equinus contracture of ankle Classification Static malunion of femur or tibia Progressive physeal growth arrest congenital absolute discrepancy increases proportion stats the same Presentation Symptoms usually asymptomatic Physical exam block testing with the patient standing, add blocks under the short leg until the pelvis is level, then measure the blocks to determine the discrepancy block testing is considered the best initial screening method tape measurement measure from the anterior superior iliac spine to the medial malleolus with a tape measure evaluate for hip, knee and ankle contractures affect apparent limb length hip adduction contracture causes apparent shortening of adducted side Imaging Radiographs teleoroentgenography (scanography) measure discrepancy with single exposure from 2m away bone age hand films determine bone age with bone age xray (hand) CT Scanography CT scanography is the most accurate diagnostic test with contractures of the hip, knee, or ankle LLD Projections General assumptions growth continues until 16 yrs in boys and until 14 yrs in girls Methods to project LLD at maturity Mosley graph estimation technique leg grows 23 mm/year, with most of that coming from the knee (15 mm/yr) proximal femur - 3 mm / yr (1/8 in) distal femur - 9 mm / yr (3/8 in) proximal tibia - 6 mm / yr (1/4 in) distal tibia - 5 mm / yr (3/16 in) Can be tracked with Green-Anderson tables uses extremity length for a given age Moseley straight line graph improves on Green-Anderson method by reformatting data in a graph form accounts for differences between skeletal and chronologic age minimizes error averages serial measurements Multiplier method prediction based on multiplying the current discrepancy by a sex and age specific factor most accurate for congenital LLD 1/2 of final leg length girls at age 3 boys at age 4 Treatment Nonoperative shoe lift or observation only indications < 2 cm projected LLD at maturity outcomes not associated with scoliosis or back pain Operative shortening of long side via epiphysiodesis of femur, tibia, or both indications 2-5 cm projected LLD limb lengthening of short side indications > 5 cm projected LLD lengthening often combined with a shortening procedure (epiphysiodesis, ostectomy) on long side physeal bar excision indications bony bridge involves <50% of physis at least 2 years left of growth amputation and prosthetic fitting indications non-reconstructable limb > 20 cm projected LLD Surgical Techniques Distraction osteogenesis (Ilizarov principles) initiation perform osteotomy and place fixator metaphyseal corticotomy to preserve medullary canal and blood supply distraction wait 5-7 days then begin distraction distract ~ 1 mm/day following distraction keep fixator on for as many days as you lengthened concurrent procedures may lengthen over a nail so ex-fix can be removed sooner lengthening often combined with a shortening procedure (epiphysiodesis, ostectomy) on long side Complications Incomplete arrest/ angular deformity open technique percutaneous technique Pin site infections Fracture Delayed union Premature cessation of lengthening Joint subluxation/dislocation Mechanical axis deviation (MAD) lengthening along the anatomical axis of the femur leads to lateral MAD shortening along the anatomical axis of the femur leads to medial MAD
Technique Guide Technique guide are not considered high yield topics for orthopaedic standardized exams including the ABOS, EBOT and RC. Growth Guided Hemiepiphysiodesis Lindsay Andras Paul D Choi Pediatrics - Hemihypertrophy
QUESTIONS 1 of 20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Previous Next (OBQ13.107) A 12-year-old male patient is scheduled to undergo femoral lengthening. The 2 techniques at your disposal are (1) femoral lengthening along the mechanical axis of the limb with an external fixator, and (2) femoral lengthening along the anatomical axis of the femur with a telescoping nail. What happens to the mechanical axis of the limb when performing these techniques? Review Topic QID: 4742 1 There is no mechanical axis deviation in (1), and medial mechanical axis deviation in (2). 32% (1137/3604) 2 There is lateral mechanical axis deviation in (1) and medial mechanical axis deviation in (2). 6% (230/3604) 3 There is no fixed direction of mechanical axis deviation in either technique. 10% (354/3604) 4 There is medial mechanical axis deviation in (1) and lateral mechanical axis deviation in (2). 6% (213/3604) 5 There is no mechanical axis deviation in (1), and lateral mechanical axis deviation in (2). 46% (1644/3604) ML 4 Select Answer to see Preferred Response PREFERRED RESPONSE 5 This is an AAOS Self assessment question. Orthobullets was not involved into the editorial process, and does not have the ability to alter. If you prefer to hide SAE questions on topics simply turn them off in your Content Settings (SAE07PE.81) A teenager is undergoing a correction of deformity and lengthening of the femur. Distractions are proceeding as expected; however, during his 6-week follow-up examination, the patient reports that the distraction motors have become harder to turn over for the past 2 to 3 days. Figures 37a and 37b show current radiographs. What is the most likely complication being encountered? Review Topic QID: 6141 FIGURES: A B 1 Incomplete corticotomy 7% (3/41) 2 Knee subluxation 2% (1/41) 3 Wire breakage 5% (2/41) 4 Poor regenerate bone formation 0% (0/41) 5 Premature consolidation 85% (35/41) ML 1 Select Answer to see Preferred Response PREFERRED RESPONSE 5 This is an AAOS Self assessment question. Orthobullets was not involved into the editorial process, and does not have the ability to alter. If you prefer to hide SAE questions on topics simply turn them off in your Content Settings (SAE07PE.31) A 14-year-old boy undergoes application of a circular frame with tibial and fibular osteotomy for gradual limb lengthening. He initiates lengthening 7 days after surgery. During the first week of lengthening, he reports that turning of the distraction devices is becoming increasingly difficult. On the 9th day of lengthening, he is seen in the emergency department after feeling a pop in his leg and noting the acute onset of severe pain. What complication has most likely occurred? Review Topic QID: 6091 1 Joint subluxation and acute ligament rupture 7% (13/175) 2 Incomplete corticotomy at the time of surgery with spontaneous completion and acute distraction 67% (117/175) 3 Premature consolidation of the osteotomy with breakage of bone transfixation wire 7% (12/175) 4 Fracture through the bone regenerate 8% (14/175) 5 Fracture of the tibia through a unicortical half-pin track 10% (18/175) ML 3 Select Answer to see Preferred Response PREFERRED RESPONSE 2 This is an AAOS Self assessment question. Orthobullets was not involved into the editorial process, and does not have the ability to alter. If you prefer to hide SAE questions on topics simply turn them off in your Content Settings (SAE07PE.19) An 8-year-old girl was treated for a Salter-Harris type I fracture of the right distal femur 2 years ago. Examination reveals symmetric knee flexion, extension, and frontal alignment compared to the contralateral knee. She has 1-cm of shortening of the right femur. History reveals that she has always been in the 50th percentile for height, and her skeletal age matches her chronologic age. Radiographs are shown in Figure 9. What is the expected consequence at maturity? Review Topic QID: 6079 FIGURES: A 1 6-cm limb-length discrepancy with the right femur longer 5% (3/62) 2 6-cm limb-length discrepancy with the left femur longer 90% (56/62) 3 12-degree varus deformity 0% (0/62) 4 18-degree valgus deformity 5% (3/62) 5 20-degree recurvatum deformity 0% (0/62) ML 1 Select Answer to see Preferred Response PREFERRED RESPONSE 2 This is an AAOS Self assessment question. Orthobullets was not involved into the editorial process, and does not have the ability to alter. If you prefer to hide SAE questions on topics simply turn them off in your Content Settings (SAE07PE.15) Which of the following is considered the best method to measure limb-length discrepancy in a patient with a knee flexion contracture? Review Topic QID: 6075 1 Obtain a standard scanogram 9% (8/89) 2 Obtain a lateral CT scanogram 66% (59/89) 3 Measure the distance from the anterior superior iliac spine to the medial malleolus 12% (11/89) 4 Measure the distance from the umbilicus to the medial malleolus 1% (1/89) 5 Stand the patient on blocks to measure the difference in the heights of the iliac wings 11% (10/89) ML 3 Select Answer to see Preferred Response PREFERRED RESPONSE 2 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 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 Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ11.203) A 13-year-old boy presents with a leg-length discrepancy with the right leg shorter than the left. He has normal height for his age and his skeletal age is equal to his chronologic age. History and examination of Tanner staging reveals that he began puberty 1 month ago. His final leg length discrepancy at skeletal maturity is projected to be 4.0cm. Which of the following surgical options is the most appropriate? Review Topic QID: 3626 1 Physeal stapling of the medial left tibial and femoral physis now with staged removal of staples at age 16 10% (281/2799) 2 Immediate lengthening of the right femur with ring external fixator 2% (59/2799) 3 Epiphysiodesis of the left femur 1 year after the onset of puberty 21% (591/2799) 4 Epiphysiodesis of the left femur and tibia 6 months from now 65% (1823/2799) 5 Epiphysiodesis of the bilateral femurs and shortening of the left tibia now 1% (23/2799) ML 3 Select Answer to see Preferred Response PREFERRED RESPONSE 4 (OBQ12.29) At what age does longitudinal growth usually arrest in boys at the distal femur physeal growth plate? Review Topic QID: 4389 1 18 10% (295/3040) 2 16 83% (2517/3040) 3 14 6% (180/3040) 4 12 1% (22/3040) 5 10 0% (7/3040) ML 2 Select Answer to see Preferred Response PREFERRED RESPONSE 2 (OBQ05.159) A 9-year-old girl presents with a history of juvenile rheumatoid arthritis, and a 20 degree flexion contracture of her left knee. A clinical photo is shown in Figure A. Which of the following is the most accurate method of determining leg length discrepancy in this patient? Review Topic QID: 1045 FIGURES: A 1 Teloradiograph 5% (67/1253) 2 Orthoradiograph 15% (184/1253) 3 Scanogram 20% (249/1253) 4 CT scanogram 59% (738/1253) 5 Bone scan 0% (6/1253) ML 3 Select Answer to see Preferred Response PREFERRED RESPONSE 4 (OBQ08.6) A 14-year-old boy sustains a significant distal femoral physeal fracture. Assuming that he has a complete growth arrest, what is the predicted leg length discrepency? Review Topic QID: 392 1 1cm 4% (87/2303) 2 2cm 88% (2017/2303) 3 3cm 5% (106/2303) 4 4cm 3% (66/2303) 5 5cm 1% (23/2303) ML 1 Select Answer to see Preferred Response PREFERRED RESPONSE 2 (OBQ04.62) A 14-year-old boy has complete growth arrest of his left proximal tibia after a skateboarding injury. He currently has a 3mm leg-length discrepancy with left shorter than the right. A radiograph of the patients left hand, wrist, and fingers demonstrate a bone-age of 14 years. What is the most appropriate management of this patient? Review Topic QID: 1167 1 Observation 63% (358/569) 2 Left tibial lengthening 1% (7/569) 3 Right tibia epiphysiodesis 30% (173/569) 4 Right femur epiphysiodesis 5% (28/569) 5 Amputation 0% (1/569) ML 3 Select Answer to see Preferred Response PREFERRED RESPONSE 1 (OBQ06.108) A 14-year-old male patient with a leg-length discrepancy undergoes a distal femoral and proximal tibial epiphysiodesis on the longer leg. What is the anticipated amount of correction achieved with this procedure in this child? Review Topic QID: 294 1 1.6 cm 3% (81/2419) 2 2 cm 6% (153/2419) 3 3.2 cm 83% (2016/2419) 4 4 cm 5% (122/2419) 5 6.4 cm 2% (37/2419) ML 1 Select Answer to see Preferred Response PREFERRED RESPONSE 3 (OBQ07.255) A 9-year-old male sustains the fracture seen in Figure A. If a complete growth arrests occurs, his expected leg length discrepancy at skeletal maturity would be? Review Topic QID: 916 FIGURES: A 1 2 cm 2% (26/1234) 2 3 cm 3% (35/1234) 3 4 cm 6% (78/1234) 4 5 cm 11% (134/1234) 5 6 cm 78% (960/1234) ML 2 Select Answer to see Preferred Response PREFERRED RESPONSE 5 Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK
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