Hunter, D J4; Lohmander, Stefan10; Makovey, J5; Tamez-Peña, J6; Totterman, S7; Schreyer, E8; Frobell, R B9
1 Department of Sports Science and Clinical Biomechanics, Det Sundhedsvidenskabelige Fakultet, SDU2 Musculoskeletal Function and Physiotherapy, Department of Sports Science and Clinical Biomechanics, Det Sundhedsvidenskabelige Fakultet, SDU3 Orthopaedics, Department of Clinical Research, Det Sundhedsvidenskabelige Fakultet, SDU4 Rheumatology Department, Royal North Shore Hospital and Kolling Institute, University of Sydney, Sydney, NSW, Australia. Electronic address: David.Hunter@sydney.edu.au.5 Rheumatology Department, Royal North Shore Hospital and Kolling Institute, University of Sydney, Sydney, NSW, Australia.6 Escuela de Medicina, Tecnológico de Monterrey, Monterrey, NL, México; Qmetrics Technologies, Rochester, NY, USA.7 Qmetrics Technologies, Rochester, NY, USA.8 Qmetrics Technologies, Rochester, NY, USA.9 Department of Orthopedics, Clinical Sciences Lund, Lund University, Lund, Sweden.10 Orthopaedics, Department of Clinical Research, Det Sundhedsvidenskabelige Fakultet, SDU
exploratory analysis in the KANON trial
OBJECTIVE: Investigate the 5-year longitudinal changes in bone curvature after acute anterior cruciate ligament (ACL) injury, and identify predictors of such changes. METHODS: In the KANON-trial (ISRCTN 84752559), 111/121 young active adults with an acute ACL tear to a previously un-injured knee had serial 1.5 T MR images from baseline (within 5 weeks from injury) to 5 years after injury. Of these, 86 had ACL reconstruction (ACLR) performed early or delayed, 25 were treated with rehabilitation alone. Measures of articulating bone curvature were obtained from computer-assisted segmentation of MR images. Curvature (mm(-1)) was determined for femur, tibia, medial/lateral femur, trochlea, medial/lateral tibia. Age, sex, treatment, BMI, meniscal injury, osteochondral fracture on baseline MR images were tested for association. RESULTS: Over 5 years, curvature decreased in each region (P < 0.001) suggesting flattening of convex shapes and increased concavity of concave shapes. A higher BMI was associated with flattening of the femur (P = 0.03), trochlea (P = 0.007) and increasing concavity of the lateral tibia (LT) (P = 0.011). ACLR, compared to rehabilitation alone, was associated with flatter curvature in the femur (P < 0.001), medial femoral condyle (P = 0.006) and trochlea (P = 0.003). Any meniscal injury at baseline was associated with a more flattened curvature in the femur (P = 0.038), trochlea (P = 0.039), lateral femoral condyle (P = 0.034) and increasing concavity of the LT (P = 0.048). CONCLUSION: ACL injury is associated with significant changes in articulating bone curvature over a 5 year period. Higher BMI, baseline meniscal injury and undergoing ACL reconstruction (as distinct from undergoing rehabilitation alone) are all associated with flattening of the articulating bone.
Osteoarthritis and Cartilage, 2014, Vol 22, Issue 7