Recent advances have allowed successful resection of partial physeal arrest in children whose physes have been damaged by trauma, infection, irradiation, and other causes. Underlying physeal anatomy and the relationship of overlying structures to the physis are vital in preparing for precise surgical excision of the bony bar. The cadaver of a 5-year-old child was dissected with special emphasis on the surgical accessibility of the physes and adjacent metaphyses of the distal radius, distal femur, proximal tibia, and distal tibia and fibula. The physis of the distal radius was found to be completely extracapsular. The synovial reflection of the suprapatellar pouch obscured portions of the anterior, medial, and lateral aspects of the distal femur. The capsular attachment extended to the level of the physis anteriorly and posteriorly. The capsular attachment to the medial distal femur was more distal and peripheral than to the lateral. The insertion of the adductor magnus tendon medially and the intermuscular septum laterally served as landmarks to the level of the physis. The physis of the proximal tibia was completely extracapsular. The posterior aspects of the physis and the metaphysis were obscured in the midline by the popliteus muscle, and this posterolateral region was the least surgically accessible of any of the regions studied. The distal tibial physis was entirely extracapsular. The anterior and posterior tibiofibular ligaments inserted across the anterolateral and posterolateral aspects of the physis of the distal fibula. This physis on its medial aspect lay intraarticularly at the level of the articular cartilage of the distal tibia.(ABSTRACT TRUNCATED AT 250 WORDS)