Anyone with a teenager is well aware of growth spurts, which lead to clothes being outgrown and fridges emptied of food. This occurs from growth plates, which are cartilaginous areas at the end of bones; upon maturity these fuse with the bone itself and growth is no longer possible.
Because of these growth plates, injuries which might result in muscle or ligament damage in an adult can cause fractures in both children and adolescents. Bone plates actually become thicker and more vulnerable in the teenage years. Avulsion fractures are common, where part of the bone is ripped off while still attached to the tendon. Cartilage at the site of tendon insertion is also weaker than in an adult, and prone to injury. Periods of rapid growth are times of higher risk, with the end of long bones, or their protuberances, often involved.
Osgood-Schlatter Disease is a common cause of knee pain in teenagers. Essentially, the patellar tendon (which runs from the kneecap) becomes inflamed where it attaches to the tibia tubercle (a lumpy protuberance on the shinbone, which covers a growth plate.), This causes tenderness just below the knee.
Osgood-Schlatter Disease often occurs during a period of a growth spurt, when the structure and alignment of bones, tendons and muscles undergo rapid change. Add on top of this the high activity level of a teenager – especially which sports requiring running and jumping – which adds to the risk of developing the condition. When active, the quadriceps muscles (of the thigh) pull on the patellar tendon, which in turns exerts traction on the tibial tubercle. This repetitive action can result in inflammation on the growth plate, with the tubercle becoming quite pronounced.
Pain is usually brought on by activities such as running or jumping. Either one or both knees can be affected, but one knee is usually more painful than the other.
Initial treatment involves simple measures such as initial rest, with simple analgesics (such as paracetamol and ibuprofen) to help relieve the pain. Both stretching and strengthening exercises (of both quadriceps and hamstrings) can also be of benefit, allowing an eventual return to usual activities. Exercise will initially need to be modified, usually until the pain disappears – pain on activity is a good gauge of healing and recovery. In rarer cases this may take a few months.
Osgood-Schlatter Disease may appear intermittently over one to two years before finally disappearing when growth spurts finish, (on average, around age14 for girls and 16 for boys). The tibial tuberosity may remain prominent but should cause no problems.
Joint preservation can start at any age, and like other health management strategies, the sooner the better. Learn more here.