What is the most likely diagnosis for a 14-year-old boy with pain and swelling on both knees, tenderness over the tibial (shin bone) tuberosity?

Osgood-Schlatter Disease

This 14-year-old basketball player most likely has Osgood-Schlatter disease, a traction apophysitis of the tibial tuberosity caused by repetitive strain from the patellar tendon during sports activities involving jumping and running. 1, 2

Clinical Presentation

The classic presentation includes:

• Bilateral knee pain and swelling over the tibial tuberosity in an active adolescent athlete 2, 3
• Age 12-15 years in boys (8-12 years in girls), coinciding with peak growth velocity 2
• Tenderness directly over the tibial tuberosity on examination, which is the hallmark finding 2, 4
• Pain exacerbated by activities involving jumping (basketball, volleyball), running, or kneeling 2, 3
• Pain relieved by rest 4

Pathophysiology

This condition represents a traction apophysitis where the powerful quadriceps muscle-patellar tendon complex repeatedly pulls on the secondary ossification center of the tibial tuberosity, which has not yet fused to the tibial bone in adolescents 2, 5. This creates a form of avulsion injury at the insertion site 5.

Diagnostic Approach

Plain radiographs are the first imaging study, showing: 6

• Irregularity and fragmentation of the tibial tubercle apophysis 2, 4
• Soft tissue swelling in acute stages (margins of patellar tendon become blurred) 3
• Heterotopic ossification of the patellar tendon 4
• Separated bone fragments at the tibial tuberosity 5

MRI is rarely needed but can be obtained if the diagnosis is uncertain or to exclude other pathology 6

Critical Differential Diagnoses to Exclude

While Osgood-Schlatter disease is most likely, you must exclude:

• Osteosarcoma or Ewing sarcoma: These present with persistent non-mechanical pain, night pain, or progressive swelling—not the activity-related pain pattern seen here 1, 6
• Osteochondroma of the tibial tuberosity: Can mimic Osgood-Schlatter but is a distinct bony lesion requiring imaging differentiation 7
• Baker's cyst: Would present with posterior knee swelling in the popliteal fossa, not anterior tibial tuberosity tenderness 8

Treatment Algorithm

90% of patients respond to conservative management: 2

1. Activity modification: Reduce or temporarily restrict sports activities involving jumping and running until symptoms resolve 2, 3
2. Ice application after activities 2
3. NSAIDs for pain relief 5
4. Quadriceps stretching exercises before sports activities 5
5. Knee band/strap to reduce traction forces on the tibial tuberosity 5

Expected timeline: Pain typically resolves within 6 months, though some cases require several months of activity restriction 3, 5

Surgical intervention is reserved for skeletally mature patients with persistent pain from a non-union ossicle that fails conservative treatment for months—this involves excision of the ossicle, surrounding bursa, and bony prominence 2, 3

Prognosis and Common Pitfalls

The condition is self-limiting and resolves with closure of the tibial growth plate, with complete recovery expected in the vast majority 2. A small percentage may experience residual discomfort with kneeling 2.

Key pitfall: Do not assume all anterior knee pain in adolescents is benign growing pains. The specific finding of tenderness directly over the tibial tuberosity distinguishes Osgood-Schlatter disease from other causes 2, 4. If the patient has persistent non-mechanical pain, night pain, or systemic symptoms, obtain imaging immediately to exclude bone malignancy 6, 1.