Osgood-Schlatter disease (OSD) is a common cause of knee pain seen in active children and teenagers during periods of rapid growth. The condition involves irritation and inflammation where the patellar tendon attaches to the shinbone, just below the kneecap. While OSD is a self-limiting problem of youth, many adults who experienced it in adolescence continue to have related issues later in life. Understanding OSD beyond skeletal maturity is important for addressing the persistent discomfort and structural changes some adults experience.
Why Osgood-Schlatter Disease is a Condition of Adolescence
Osgood-Schlatter disease is fundamentally tied to the presence of a growth plate, making it unique to adolescence. The growth plate, specifically the tibial tubercle apophysis, is an area of soft, growing cartilage near the top of the shinbone that serves as the attachment point for the patellar tendon.
During a growth spurt, bones often lengthen faster than surrounding muscles and tendons, increasing tension in the quadriceps muscle group. This tension is transmitted through the patellar tendon, pulling forcefully on the vulnerable cartilage of the growth plate. Repetitive stress from sports causes microtrauma, inflammation, and sometimes small avulsions, or separations, of cartilage and bone fragments. This constant mechanical irritation of actively growing tissue is why OSD occurs almost exclusively in adolescents.
The Status of OSD After Skeletal Maturity
The active disease process of Osgood-Schlatter cannot exist once a person reaches skeletal maturity. Skeletal maturity occurs when the growth plates fuse, meaning the soft cartilage hardens into solid bone. This fusion usually occurs around age 14 for girls and age 16 for boys, resolving the mechanical problem that caused the condition.
Once the tibial tubercle apophysis has completely ossified and fused to the tibia, the patellar tendon attachment site is no longer susceptible to repetitive traction injury. While the inflammatory disorder known as OSD is self-limiting, the structural aftermath of the condition may remain, leading to complications in adulthood.
Residual Pain and Adult Complications
Although the active disease is gone, approximately 10% of individuals who had OSD in their youth continue to experience symptoms into adulthood. The most common residual feature is a persistent, noticeable bony prominence, or “bump,” at the top of the shinbone. This prominence results from the body’s healing response to microtrauma and can cause chronic, localized pain, especially upon direct pressure or kneeling.
A specific complication causing significant adult pain is the presence of an ununited ossicle. An ossicle is a small piece of bone torn away from the growth plate during adolescence that never fully fused back into the tibia. This non-union fragment can remain embedded within the patellar tendon or adjacent soft tissue, causing ongoing irritation and pain that worsens with activity.
The prominent bump can also lead to secondary issues. These include localized bursitis, which is inflammation of the fluid-filled sac over the protrusion, or soft tissue impingement when the knee is fully extended.
Treatment Options for Adult Symptoms
Management of adult symptoms resulting from prior OSD begins with conservative, non-surgical approaches. Initial treatment focuses on reducing inflammation and managing pain using over-the-counter non-steroidal anti-inflammatory drugs (NSAIDs). Physical therapy is a cornerstone of conservative care, aiming to improve flexibility and strengthen surrounding muscles, particularly the quadriceps and hamstrings, to reduce tension on the patellar tendon attachment.
Activity modification, such as avoiding excessive jumping or kneeling, is often recommended. Using protective padding or specialized knee straps can help cushion the prominent bony bump and alleviate discomfort caused by direct pressure.
For cases where conservative management fails to relieve severe, chronic pain, surgical intervention may be considered, particularly when an ununited ossicle is confirmed. The surgical procedure typically involves the excision, or removal, of the painful ossicle or the shaving down of a severely prominent tibial tubercle. Ossicle excision can offer significant symptom resolution when residual fragments are the primary source of adult discomfort.