Assessment of skeletal maturity in scoliosis patients to determine clinical management: a new classification scheme using distal radius and ulna radiographs

Abstract Background Assessment of skeletal maturity in patients with adolescent idiopathic scoliosis (AIS) is important to guide clinical management. Understanding growth peak and cessation is crucial to determine clinical observational intervals, timing to initiate or end bracing therapy, and when to instrument and fuse. The commonly used clinical or radiologic methods to assess skeletal maturity are still deficient in predicting the growth peak and cessation among adolescents, and bone age is too complicated to apply. Purpose To address these concerns, we describe a new distal radius and ulna (DRU) classification scheme to assess skeletal maturity. Study design A prospective study. Patient sample One hundred fifty young, female AIS patients with hand x-rays and no previous history of spine surgery from a single institute were assessed. Outcome measures Radius and ulna plain radiographs, and various anthropomorphic parameters were assessed. Methods We identified various stages of radius and ulna epiphysis maturity, which were graded as R1–R11 for the radius and U1–U9 for the ulna. The bone age, development of sexual characteristics, standing height, sitting height, arm span, radius length, and tibia length were studied prospectively at each stage of these epiphysis changes. Results Standing height, sitting height, and arm span growth were at their peak during stages R7 (mean, 11.4 years old) and U5 (mean, 11.0 years old). The long bone growths also demonstrated a common peak at R7 and U5. Cessation of height and arm span growth was noted after stages R10 (mean, 15.6 years old) and U9 (mean, 17.3 years old). Conclusions The new DRU classification is a practical and easy-to-use scheme that can provide skeletal maturation status. This classification scheme provides close relationship with adolescent growth spurt and cessation of growth. This classification may have a tremendous utility in improving clinical-decision making in the conservative and operative management of scoliosis patients.