Methods of Assessing Skeletal Maturity When Planning Surgeries About the Knee

Increased participation in youth sports has led to more knee injuries necessitating surgical intervention. Among the youngest athletes, such procedures typically involve physeal-respecting techniques for anterior cruciate ligament reconstruction, medial patellofemoral ligament reconstruction for patellar instability, osteochondritis dissecans fixation, and implant-mediated guided growth procedures. In each case, the choice of appropriate intervention is critically dependent on a patient's skeletal maturity. Compared with chronologic age, skeletal age accounts for individual maturation and is the benchmark for determination of development in orthopaedics. This is historically assessed using the Greulich and Pyle method, in which bone age is determined through comparison of a patient's hand radiograph with the closest standard radiograph from an atlas of American children from the early 1900s. In the setting of knee pathology, obtaining additional imaging requires further radiation and time. Several bone age determination methods exist incorporating radiographic characteristics of the distal femur, proximal tibia, and/or proximal fibula. This study therefore sought to review available methods for determination of skeletal age when planning surgeries about the knee using readily available, routine knee imaging. The review focuses on both radiograph and MRI-based skeletal maturity staging systems that surgeons may use to guide appropriate treatment while describing the strengths and weaknesses of each method.