Iliotibial band (friction) syndrome is a common cause of lateral knee pain related to intense physical activity resulting in chronic inflammation. Alternatively, the same pathology can occur over the greater trochanter and is considered the same diagnosis.
Commonly affect young patients who are physically active, most often long-distance runners or cyclists. The exact prevalence is unknown, but one study has found the prevalence among actively training marines to be higher than 20% 5. Iliotibial band syndrome accounts for 12% of running-related overuse injuries 4.
Classically, iliotibial band syndrome is diagnosed by history and physical examination. Pain over the greater trochanter or at the lateral knee joint is the presenting symptom with point tenderness 1-2 cm above the lateral joint line. Pain is usually worse with downhill running and increases throughout an episode of activity 4.
When the knee flexes, the iliotibial band (ITB) moves posteriorly over the lateral femoral epicondyle. When the band is excessively tight or stressed, the ITB rubs against the epicondyle irritating the lateral synovial recess.
WIth hip flexion, the ITB slides anteriorly over the greater trochanter and may cause a painful clunking sensation or audible snap.
The following physical factors are reported to be associated with the development of the syndrome 4:
- limb length discrepancy
- genu varum
- hip adductor weakness
- myofascial restriction
The histologic analysis demonstrates inflammation and hyperplasia in the synovium.
Allows visualization of the impingement by assessing dynamic motion of the ITB through knee flexion and extension.
MRI is reserved for when the diagnosis is unclear and to exclude other etiologies of lateral knee pain such as a meniscal tear or lateral collateral ligament injury.
MR findings of ITB syndrome include ill-defined signal abnormality within the fatty soft tissues interposed between the ITB and bone. In the knee, the soft tissues lateral to the lateral femoral condyle show low T1 and high on T2 signal, in keeping with edema/fluid. In the hip, similar soft tissue changes are present and there may also be tendinopathy or tear of the gluteus medius or minimus tendons. There may also be marrow edema in the affected bone.
Cystic areas representing primary or secondary (adventitious) bursae may be identified.
Chronic MR findings include thickening of the ITB and increased T2 signal intensity superficial to the ITB are occasionally seen. Soft tissue fibrosis and bony proliferation may be present.
Treatment and prognosis
Initial treatment is conservative, consisting of physical therapy, anti-inflammatory medication, and steroid injections 3.
Surgical treatment is reserved only for those who fail conservative treatment and includes resection of the posterior aspect of the ITB 3.
General imaging differential considerations include:
- 1. Haims AH, Medvecky MJ, Pavlovich R et-al. MR imaging of the anatomy of and injuries to the lateral and posterolateral aspects of the knee. AJR Am J Roentgenol. 2003;180 (3): 647-53. AJR Am J Roentgenol (full text) - Pubmed citation
- 2. Muhle C, Ahn JM, Yeh L et-al. Iliotibial band friction syndrome: MR imaging findings in 16 patients and MR arthrographic study of six cadaveric knees. Radiology. 1999;212 (1): 103-10. Radiology (full text) - Pubmed citation
- 3. Khaund R, Flynn SH. Iliotibial band syndrome: a common source of knee pain. Am Fam Physician. 2005;71 (8): 1545-50. Am Fam Physician (link) - Pubmed citation
- 4. Hong JH, Kim JS. Diagnosis of iliotibial band friction syndrome and ultrasound guided steroid injection. Korean J Pain. 2013;26 (4): 387-91. doi:10.3344/kjp.2013.26.4.387 - Free text at pubmed - Pubmed citation
- 5. Linenger JM, West LA. Epidemiology of soft-tissue/musculoskeletal injury among U.S. Marine recruits undergoing basic training. Mil Med. 1992;157 (9): 491-3. - Pubmed citation
- 6. Jelsing EJ, Finnoff JT, Cheville AL et-al. Sonographic evaluation of the iliotibial band at the lateral femoral epicondyle: does the iliotibial band move?. J Ultrasound Med. 2013;32 (7): 1199-206. doi:10.7863/ultra.32.7.1199 - Pubmed citation
- 7. William Palmer, Laura Bancroft, Fiona Bonar, Jung-Ah Choi, Anne Cotten, James F. Griffith, Philip Robinson, Christian W.A. Pfirrmann. Glossary of terms for musculoskeletal radiology. (2020) Skeletal Radiology. doi:10.1007/s00256-020-03465-1 - Pubmed
- 8. Jiménez Díaz F, Gitto S, Sconfienza LM, Draghi F. Ultrasound of iliotibial band syndrome. (2020) Journal of ultrasound. 23 (3): 379-385. doi:10.1007/s40477-020-00478-3 - Pubmed
Related Radiopaedia articles
The knee is a complex synovial joint that can be affected by a range of pathologies:
- bone and cartilage
- distal femoral condyle fracture
- tibial plateau fracture (classification)
- patella fracture
avulsion fractures of the knee
- arcuate complex avulsion fracture (arcuate sign)
- anterior cruciate ligament avulsion fracture
- biceps femoris avulsion fracture
- iliotibial band avulsion fracture
- patella fracture
- posterior cruciate ligament avulsion fracture
- reverse Segond fracture
- Segond fracture
- semimembranosus tendon avulsion fracture
- Stieda fracture
- chondromalacia patellae
- osteoarthritis of the knee
- osteochondral defects
- osteochondritis dissecans of the knee
- patterns of bone bruise in knee injury
- knee fractures
- anterior cruciate ligament tear
- anterior cruciate ligament ganglion cyst
- anterior cruciate ligament mucoid degeneration
- posterior cruciate ligament tear
- medial collateral ligament tear
- lateral collateral ligament tear
- medial patellofemoral ligament tear
- posterolateral corner injury
- posteromedial corner injury
- meniscal lesions
- longitudinal tear
- radial tear
- root tear
- displaced tear
- MRI grading system for meniscal signal intensity
- meniscal contusion
- meniscal extrusion
- meniscal/parameniscal cyst
- meniscal flounce
- meniscal fraying
- meniscal maceration
- meniscocapsular separation
- floating meniscus
- meniscal tear
- bursosynovial lesions
- fat pad
- popliteal fossa
- patellar instability
- patella alta
- patella baja