Patient Presentation
A 14-year-old female came to clinic with a history of bilateral knee pain. She noticed more pain when she was playing late winter volleyball and had added 3 times/week indoor soccer practice to get ready for the spring high school season. The pain was symmetric and would worsen during the practices and improve after stopping practice and with ice. She did not limp during the day but said that going up stairs seemed to make it worse. She denied any specific trauma but was falling on her knees with volleyball and would get tackled in soccer. She denied anything that made sounds and her knees did not “catch,” and did not have morning stiffness or swelling. The past medical history was positive for an ankle sprain more than 12 months before.

The pertinent physical exam showed a healthy female in no specific distress. Bilateral tibial tuberosities were slightly swollen and the pain was reproduced with palpation of the area and quadriceps activity. The patella did not appear misaligned at rest and through range of motion. There was no pain along the joint line and meniscal and cruciate maneuvers were normal. She did seem to have tight quadriceps and hamstring muscle groups.

The diagnosis of Osgood-Schlatter apophysitis was made. Bilateral knee plain radiographs were normal and were completed to confirm no specific osseous problems as the patient had ongoing knee trauma due to her sports.

The patient’s clinical course 2 months later, showed that she had stopped winter soccer training and had started physical therapy and cross-training. She did continue modified volleyball practices in the winter, and transitioned to soccer practices in the early spring. Her pain was markedly improved and only mildly affecting her with intensive soccer practice or competition. She continued supervised athletic training and physical therapy.

Discussion
An apopysis is a secondary ossification center located at the tendinous insertion into a bone. Site irritation is called apophysitis and several proposed causes include genetics, rapid growth, trauma (compression or traction), anatomical differences and diet. Whatever the etiological factors, it causes pain. Examples include Sever’s disease of the calcaneus.

Anterior knee pain is a common presenting problem in the pediatric age group, and the differential diagnosis is broad. Trauma, infection, tumors, and referred pain need to be considered but soft tissue problems tend to predominate if not a traumatic cause. Trauma could be overlooked by the patient though. The knee’s anatomy is complex, and this along with normal pubertal growth and biomechanics can make the diagnosis more challenging. Sports participation for recreational or competition is a common cause. Females have had increased knee problems because of increased activity and hips/legs anatomy (e.g. anterior cruciate ligament problems have rapidly increased in female athletes) in the past few years. High levels of repetitive activity where the knee is loaded such as kicking, jumping, squatting and sprinting place increased risk for overuse knee injuries. Thus common sports include baseball/softball, basketball, gymnastics, soccer and volleyball.

Osgood-Schlatter apophysitis is one of the most common apophysites (21% of teen athletes and 4.5% of non-athletes) and affects the tibial tuberosity. The cause is felt to be repetitive overload of the patella, knee and tibial structures, along with potential alignment problems, tight tissue and muscle imbalances, which may cause strain and small avulsion fractures of the tibial tuberosity. The pain commonly has a gradual onset and is worsened with specific loading knee activities such as walking up stairs, kneeling or repetitive sport activity. Pain is localized to the tibial tuberosity which may be mildly swollen, and the patellar tendon may feel thickened. Pain may be provoked with quadriceps activity even in the office. The pain usually is improved with stopping or decreasing activity. Even with treatment, pain can persist until the tibial tubercle apophysis closes or after.
While a patient’s gender, size and height are usually not modifiable risk factors for prevention, training programs and routines can be. Increased training should be done stepwise with small increases. Cross-training and multiple sport participation can also help. Training surfaces should provide safety and comfort and be exchanged on a regular basis.

Learning Point
Treatment for Osgood-Schlatter apophysitis is symptomatic and rehabilitative. About 90% of patients respond to this treatment. Symptomatically rest and icing can improve the pain. Non-steroidal anti-inflammatory drugs can also help. Rehabilitation includes physical therapy to help with biomechanics, flexibility, and strength. Although patients and families often wish to focus solely on the painful area, all areas of the lower extremity need improved flexibility and strengthening to help with muscular imbalance. Important areas do include quadriceps, iliotibial bands, hamstrings, and gluteals. Strengthening of the core musculature and overall balance is also helpful.

Patients should rest the affected joint but still can exercise. Patients can cross-train to continue cardiovascular fitness and maintain conditioning of other body areas. Good non-impact, non-loading choices would be swimming, biking or an elliptical.

Knee braces or sleeves and taping can help with short-term pain but have not been shown to be helpful long-term. The outcomes of cushioning devices such as shoe inserts are inconclusive. Steroid injections are usually not used because of the potential for patellar tendon rupture. Other injections may have some effects and more studies are being completed. Surgical interventions can be used for potential relief long-term pain if necessary but usually are not needed.

Patients can return to activity if they are pain-free, or for some patients if supervised, they can return if pain can be tolerated, is not increasing with the exercise using proper form, and does not cause other functional problems such as difficulty walking, sitting etc.

Questions for Further Discussion
1. How do you treat anterior knee pain and what are your indications for referral?
2. What is the long-term outcome of anterior cruciate ligament repair? A review can be found here
3. What causes limping? A review can be found here

Related Cases

Disease: Osgood-Schlatter Apophysitis | Knee Injuries and Disorders

Symptom/Presentation: Lower Extremity Trauma | Pain

Specialty: Orthopaedic Surgery and Sports Medicine | Physical Medicine and Rehabilitation / Physical Therapy

Age: Teenager

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for this topic: Knee Injuries and Disorders

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Slotkin S, Thome A, Ricketts C, Georgiadis A, Cruz A, Seeley M. Anterior Knee Pain in Children and Adolescents: Overview and Management. J Knee Surg. 2018;31(05):392-398. doi:10.1055/s-0038-1632376

Ladenhauf HN, Seitlinger G, Green DW. Osgood-Schlatter disease: a 2020 update of a common knee condition in children. Curr Opin Pediatr. 2020;32(1):107-112. doi:10.1097/MOP.0000000000000842

Kraus E, Rizzone K, Walker M, et al. Stress Injuries of the Knee. Clin Sports Med. 2022;41(4):707-727. doi:10.1016/j.csm.2022.05.008

Molony JT, Greenberg EM, Weaver AP, Racicot M, Merkel D, Zwolski C. Rehabilitation After Pediatric and Adolescent Knee Injuries. Clin Sports Med. 2022;41(4):687-705. doi:10.1016/j.csm.2022.05.007

Author
Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa