BACKGROUND: Achondroplasia is the most common form of skeletal dysplasia. Although the radiographic features are well described, MRI features of the knee in achondroplasia have not been reported. OBJECTIVE: To describe common MRI characteristics of the knee joint in symptomatic children and adolescents with achondroplasia. MATERIALS AND METHODS: We retrospectively evaluated 10 knee MRI examinations in 8 children and young adults (age range 11-20 years, mean 16.3 years) with achondroplasia. We measured modified Insall-Salvati index, knee flexion angle, anterior cruciate ligament (ACL)-Blumensaat line angle, ACL-tibial angle, posterior cruciate ligament (PCL) angle, intercondylar notch width index, and intercondylar notch depth index. We compared our findings with an age- and gender-matched control group of 20 children (age range 15-18 years; mean 16 years) with normal knee MRIs. RESULTS: All 10 knees in the achondroplasia group had discoid lateral meniscus; 8 meniscal tears were identified. Patella baja was present in half of the study cases. Greater knee flexion and increased ACL-Blumensaat line and PCL angles were seen in all achondroplasia knees. ACL-tibial angle was similar in the study and in the control group. Children with achondroplasia had deeper A-shape femoral notches that extended more anteriorly than those seen in the control group. MRI findings were confirmed in all seven knees with arthroscopic correlation. CONCLUSION: Discoid lateral meniscus, often with tear, is a consistent feature in knee MRIs of symptomatic children and adolescents with achondroplasia. Other findings include patella baja, knee flexion, deep A-shape intercondylar notch, increased ACL-Blumensaat line angle and taut PCL.
BACKGROUND:Achondroplasia is the most common form of skeletal dysplasia. Although the radiographic features are well described, MRI features of the knee in achondroplasia have not been reported. OBJECTIVE: To describe common MRI characteristics of the knee joint in symptomatic children and adolescents with achondroplasia. MATERIALS AND METHODS: We retrospectively evaluated 10 knee MRI examinations in 8 children and young adults (age range 11-20 years, mean 16.3 years) with achondroplasia. We measured modified Insall-Salvati index, knee flexion angle, anterior cruciate ligament (ACL)-Blumensaat line angle, ACL-tibial angle, posterior cruciate ligament (PCL) angle, intercondylar notch width index, and intercondylar notch depth index. We compared our findings with an age- and gender-matched control group of 20 children (age range 15-18 years; mean 16 years) with normal knee MRIs. RESULTS: All 10 knees in the achondroplasia group had discoid lateral meniscus; 8 meniscal tears were identified. Patella baja was present in half of the study cases. Greater knee flexion and increased ACL-Blumensaat line and PCL angles were seen in all achondroplasia knees. ACL-tibial angle was similar in the study and in the control group. Children with achondroplasia had deeper A-shape femoral notches that extended more anteriorly than those seen in the control group. MRI findings were confirmed in all seven knees with arthroscopic correlation. CONCLUSION: Discoid lateral meniscus, often with tear, is a consistent feature in knee MRIs of symptomatic children and adolescents with achondroplasia. Other findings include patella baja, knee flexion, deep A-shape intercondylar notch, increased ACL-Blumensaat line angle and taut PCL.
Authors: Ravi Savarirayan; Penny Ireland; Melita Irving; Dominic Thompson; Inês Alves; Wagner A R Baratela; James Betts; Michael B Bober; Silvio Boero; Jenna Briddell; Jeffrey Campbell; Philippe M Campeau; Patricia Carl-Innig; Moira S Cheung; Martyn Cobourne; Valérie Cormier-Daire; Muriel Deladure-Molla; Mariana Del Pino; Heather Elphick; Virginia Fano; Brigitte Fauroux; Jonathan Gibbins; Mari L Groves; Lars Hagenäs; Therese Hannon; Julie Hoover-Fong; Morrys Kaisermann; Antonio Leiva-Gea; Juan Llerena; William Mackenzie; Kenneth Martin; Fabio Mazzoleni; Sharon McDonnell; Maria Costanza Meazzini; Josef Milerad; Klaus Mohnike; Geert R Mortier; Amaka Offiah; Keiichi Ozono; John A Phillips; Steven Powell; Yosha Prasad; Cathleen Raggio; Pablo Rosselli; Judith Rossiter; Angelo Selicorni; Marco Sessa; Mary Theroux; Matthew Thomas; Laura Trespedi; David Tunkel; Colin Wallis; Michael Wright; Natsuo Yasui; Svein Otto Fredwall Journal: Nat Rev Endocrinol Date: 2021-11-26 Impact factor: 47.564
Authors: M Del Pilar Duque Orozco; N C Record; K J Rogers; M B Bober; W G Mackenzie; A Atanda Journal: J Child Orthop Date: 2017-06-01 Impact factor: 1.548
Authors: David T Sims; Gladys L Onambélé-Pearson; Adrian Burden; Carl Payton; Christopher I Morse Journal: Front Physiol Date: 2018-07-20 Impact factor: 4.566