The tibial tuberosity is the bony lump on the shin below the kneecap (patella) where the patellar tendon attaches. It is also called the tibial tubercle.
Why is the tibial tuberosity sometimes problematic?
The tibial tuberosity develops separately from the main tibia bone, and has its own growth plate. This growth plate closes after puberty. In young people who do a lot of jumping sport, there may be traction on the growth plate (osgood Schlatter's disorder) or the bone may fracture there. There are also various alignment disorders of the several elements of the chain that allows the knee to extend (quads, patella, patellar groove), and this may also cause stress on the tibial tuberosity.
Factors Affecting Tibial Tuberosity-Trochlear Groove Distance in Recurrent Patellar Dislocation Prakash J, Seon J-K, Ahn H-W, Kyu-Jin Cho, Im C-J and Song EK. Clin Orthop Surg. 2018 Dec; 10(4): 420–426.
Tibial Tuberosity Osteotomy for Patellofemoral Realignment Alters Tibiofemoral Kinematics Mani S, Kirkpatrick MS, Saranathan A, Smith LG, Cosgarea AJ and Elias JJ. Am J Sports Med. 2011 May; 39(5): 1024–1031.