Iliotibial Syndrome (Part 2) Diagnosis
The identification of iliotibial syndrome (ITBS) is tricky because there has not been an internationally recognized clinical diagnostic criteria for it. Hence to me, the main diagnosis involves the elimination of differential diagnosis, correlation with patient history, muscular and provocative test and gait cues. Imaging too could be used to confirm diagnosis and to remove ambiguity of possible differential diagnosis.
Differential Diagnosis
As adapted (Not exhaustive) by (Rosenthal, 2008), these are the possible diagnosis for lateral knee pain.
• Patellofemoral syndrome • Iliotibial band syndrome • Lateral meniscus tear • Lateral collateral ligament sprain • Lateral compartment osteochondral injury/arthritis • Patellar instability and tendinopathy• Common fibular (peroneal) nerve injury • Popliteal artery entrapment • Lumbar radiculopathy • Distal femur/Proximal Tibia bone stress injury
There are many structures that pass through or are at the location of the lateral knee complex and it is no surprise that there could be many possible causes of discomfort at that area.
- Nerve related pathologies
The key distinguishing difference is that with nerve related pathologies, the pain/discomfort/irritation usually covers a wide diffuse area that travels distally. The nature of pain would also be representative of nerve injury which is numbing, burning or ‘’pins and needles’’- like. Compression related nerve pain would also be classically elicited with certain specific movements. The straight leg raise test and it’s variations are useful in its determination.
- Popliteal artery entrapment
Similar to the presentation of pain of nerve related pathologies, but this is accompanied by a feeling of tiredness and heaviness of the leg. Skin and temperature changes could also be a sign. It is usually relieved on rest just after exercise(If there isn’t a clot or a sign of peripheral artery disease). Simple tests would be to feel the pulse of the artery and palpate again after some light exercise or movement. An Ultrasound could also be useful to see how the artery behaves under passive/active compression of surrounding muscles.
- Bone stress injuries
A bone stress injury could occur with overloading of the structures or a blunt trauma. Focal intense pain along the bone margins, night pain and pain upon traumatic actions (Such as single hops) are good signs to suspect bone injuries. A fulcrum test could also be done depending on the location of the injury. However, a clearer picture would have to be found with consideration of pathologies that surround the knee joint capsule.
- Knee articular related structures
Knee joint swelling, effusion or skin changes across the knee joint point to intra-articular injuries of the knee. This leads to more plausible pathologies as mentioned below.
- Osteoarthritis
Relevant medical history related to Osteoarthritis should be considered (Age, Obesity, previous injury). Morning stiffness and pain which gets better with movement, crepitus, pain upon movement and restricted range of motion are key signs in OA.
2. Lateral Knee meniscus injury
Trauma when the knee is in flexion, torsional blunt force in sport or long term overload of high impact forces can cause meniscus injury. Tests include the McMurray Test and knee joint line palpation.
3. Lateral collateral ligament sprain
Trauma is the key determiner here, with an outward blunt trauma to the medial side of the knee a tell tale factor. However, any force that causes the knee to buckle outwards through jumping, start-stop sprints or changes in direction are also indicative. Test include the varus knee test for pain and laxity.
- Patellofemoral tendinopathy and patella tendinopathy
These 2 pathologies are closely related to the diagnosis of iliotibial syndrome and writing on how to distinguish these 2 from ITBS and even within itself would require different articles on their own. However, the location and pattern of pain, sport and medical history is important in distinguishing them. A good roundup video is provided by Physiotutors (Link below)
- Iliotibial syndrome
With suspecting ITBS for lateral knee pain, the elimination of its differential diagnosis is required for its clearer diagnosis. This is particularly due to ITBS not having a specific diagnosis criteria.
The typical patient profile would be those involved in cyclic sports such as running or cycling. Training errors such as improper/sudden increasing of mileage with lack of accompanied strength training, and hill training with an emphasis of downhill running are key clues for ITBS. Feelings of knee frontal plane instability, feeling that the band would snap and pain that would stop exercise are also noteworthy.
ITBS typically presents as tenderness at 2–3cm above the lateral knee joint line, with pain more pronounced when the knee is flexed at about 20–30 degrees (Noble, 1979) during mid stance to late stance (Which is the purported region of compression of the fat pad between the epicondyle at the iliotibial band). You would commonly hear patients saying that the pain occurred suddenly during exercise. Although, cases of increasing noticeable pain around the lateral knee area can be common. Pain reproduction in the stance limb during squatting down and climbing down the stars are classic complaints (Hutchinson, Lichtwark, Willy and Kelly, 2022., Geiser, 2021., Geisler and Lazenby, 2017.,Aderem and Louw, 2015).
For less acute cases, the patient might comment that the pain only resurfaces upon exercise. Usually, pain is then reproduced at a specific/reliable point in the exercise with a increase in intensity (Louw and Deary, 2013)
Clinical Tests for ITBS
Again, there are no specific tests to confirm ITBS. But the 2 most commonly commented for ITBS are the Noble and Ober Test, despite them having no known studies being done to determine sensitivity and specificity for the pathology.
- Noble test
This test involves placing pressure on area of concern with the knee initially flexed at 90 degrees. The knee is gradually extended whilst keeping the pressure on the area. A positive result would be when the pain is worse experienced when the knee is flexed to 20–30 degrees.
This test was first described in 2 key papers by C.A. Noble in 1979 and 1980 and was then adopted into many clinical rooms ever since. Although the test has not been validated, we could see how theory-wise it could suggest ITB. This, however, has to be done in tandem with your clinical cues and judgement.
- Ober Test and the Modified Ober Test (Rosenthal, 2008)
The original Ober test involves letting the patient lie on their side with their hips in neutral flexion. Make sure that there is open space unrestricted by the couch behind the patient to allow the affected leg to drop below the waist. (But don’t let them fall!) With the affected leg, flex the knee to 90 degrees while adducting and extending the hip posterior to the unaffected leg, letting gravity further adduct the leg. A positive result would result in the leg being unable to go beyond the plane on the unaffected leg. In other words, the affected leg does not drop down and is held by the tight soft tissues at the hip and knee level. Again, what was thought was that this indicated that the ITB itself was tight and that it was of a short length.
The modified Ober test has the same procedure with the difference being the affected knee being extended instead of flexing it to 90 degrees. To help the patient, the pelvis is also manually stabilized so that they do not fall off the couch and go into lumbar flexion. This in theory, reduces the influence of a tight Rectus Femoris affecting results when the knee is flexed to 90 degrees.
- Appropriateness of Ober Test
However, the Ober test does not necessarily tell us a patient has ITBS.
Firstly, considering its function; its composition of multiple distal aspects of large muscle bodies, attachment points and that it is a thickened fascia made up of collagenous and tendinous components; the iliotibial band was going to be a tight structure to begin with. Thinking of how important tension is to the plantar fascia (although not exactly similar), we would expect the iliotibial band to have some relative stiffness.
Secondly, there has been no studies to show that a positive Ober test is strongly associated to ITBS. In a study to determine the normative and critical criteria for ITB by (Ferber, Kendall and McElroy, 2010), 169 subjects were deemed to have a positive Ober test whereas the subject pool only had 31 reported subjects with ITBS. Moreover, (Friede, Klauser, Fink and Csapo, 2020) also found that baseline characteristics for those with ITBS and healthy controls did not show any significant difference in stiffness of the ITBS.
Lastly, a study by (Willett, Keim, Shostrom and Lomneth, 2016) used 18 cadavers and found that transecting the ITB did not have any significant changes in the values of modified Ober test and Ober test. A notable difference was only found after the gluteus Medius and Minimus were transected.
The key takeaway here is that a positive Ober test in clinic should not be a key indicator that a patient is suffering from ITBS. It is not a useless test though as it is still able to determine a rough baseline of how stiff the ITB and its associated structures are pre-intervention. This hence, provides a comparison point during the treatment.
- Gait and Biomechanical cues
Gait cues include
A contralateral pelvic drop, hip internal rotation and adduction (Especially during loading phase of stance), dynamic knee valgus and adduction and excessive foot pronation leading to tibial internal rotation.
Statically observing the patient; a pelvic slouch from an asymmetrical standing position, a Varus knee position, internally rotated tibia, or a pes planus foot type could also be associated with ITB.
An observed contralateral pelvic drop (Geiser, 2020) could lead to an excessive knee adduction moment. This is measured by drawing the ground reaction force vector straight up to the medial side of the knee upon heel strike. This is speculated to cause tensile strain on the ITB. A lack of observed contralateral pelvic drop could also be compensated by increased ipsilateral trunk flexion, which have been observed in female runners.
Hip abduction, internal rotation, and dynamic knee valgus (Geisler and Lazenby, 2017., Louw and Deary, 2013) during mid stance, elongates the ITB and possibly increases tensile and torsional strain on the ITB. This might also induces greater stress on the innervated fat pad between the femoral epicondyle and the ITB band causing inflammation.
A varus stance position or a varus thrust upon initial contact could lead to an increased speed in dynamic valgus collapse of the knee. This is due to the knee having to travel a greater distance in the same amount of time as compared to a neutral knee position. Consequently, this increases the strain rate of the ITB which could be another factor behind ITBS (Noehren et al., 2014., Hamill, Miller, Noehren and Davis, 2008). Giving some support to this theory, a study of 26 cadets by (Stickley et al., 2018) found that there was an increased knee varus thrust in the early stance phase of gait for army cadets that went on to develop ITBS.
Biomechanical Cues
Weakness in Hip abductor and external rotator strength has been indicated to be a potential factor towards ITBS. While external rotator strength has been fairly less documented and more of in agreement (Noehren et al., 2014., Friede, Klauser, Fink and Csapo, 2020), studies for hip abductor strength are largely splintered. There has been an increasing trend to not find any differences in hip abductor strength between ITBS runners and controls (Friede, Klauser, Fink and Csapo, 2020., Foch et al., 2015, Noehren et al., 2014., Grau et al., 2011). However it is still hard to definitively exclude it as part of a clinical clue due to the biomechanical implications poor hip abductor strength can cause. Especially when prospective studies for iliotibial band syndrome has found biomechanical factors that could be related to hip abduction strength (Hamill, Miller, Noehren and Davis, 2008). Hopefully, future prospective studies can help to alleviate this fog on hip abductor weakness.
Similarly, an increased hip internal rotation to external rotation could also indicate an increased propensity for an observed dynamic knee valgus. This can be also associated to poor hip muscle strength (Ferreira et al., 2018)
Overall Hip and knee postural stability would be indicative as this could increase strain and strain rates on the ITB to control frontal plane knee stability. A good thing to try out would be to allow your patients to balance on 1 single leg and progress with a single leg squat, keeping a good eye on how the hip and knee behave in the frontal plane.
Factors that affect excessive foot pronation could also be indicative. Hence, things like calf equinus can be something to look out for.
Limitations
Although most of the above cues can give us a general direction of what to look out for, there are limitations to relating certain research variables to the actual patient. Many of the research towards biomechanical reasonings behind ITB are largely based on subjects undergoing running trials, hence, the above mentioned cues might not be totally transferable to walking gait. Moreover, there has been reported significant differences between gender thus certain cues might hold more or less weight depending on who you are seeing in clinic(Phinyomark et al., 2015).
Imaging
Specific pathology involving the ITBS would be best visualized by MRI which would be able to identify adjacent edema or intrasubstance signal changes. It could also identify specific differential diagnosis surrounding the lateral component of the knee (Agridag Ucpinar, Bankaoglu, Eren and Erturk, 2020., Flato et al., 2017). Ultrasound of the ITB can also correlate findings if available in clinic.
Conclusion
In terms of diagnosis, I feel it is important to relate the pathogenesis of ITB to guide the clinical reasoning behind diagnosis. With that, certain factors that the patient presents at that time would make more sense leading to a clearer diagnosis. ITBS is not an easy pathology and I have yet to see enough patients to say that I have got a slight hold on the topic. Will be looking forward to more learning opportunities in clinic to understand even more on this interesting pathology.
References
Aderem, J. and Louw, Q., 2015. Biomechanical risk factors associated with iliotibial band syndrome in runners: a systematic review. BMC Musculoskeletal Disorders, 16(1).
Agridag Ucpinar, B., Bankaoglu, M., Eren, O. and Erturk, S., 2020. Measurement of iliotibial band diameter in iliotibial band friction syndrome and comparison with an asymptomatic population. Acta Radiologica, 62(9), pp.1188–1192.
Ferber, R., Kendall, K. and McElroy, L., 2010. Normative and Critical Criteria for Iliotibial Band and Iliopsoas Muscle Flexibility. Journal of Athletic Training, 45(4), pp.344–348.
Ferreira, A., de Oliveira Silva, D., Briani, R., Ferrari, D., Aragão, F., Pazzinatto, M. and de Azevedo, F., 2018. Which is the best predictor of excessive hip internal rotation in women with patellofemoral pain: Rearfoot eversion or hip muscle strength? Exploring subgroups. Gait & Posture, 62, pp.366–371.
Flato, R., Passanante, G., Skalski, M., Patel, D., White, E. and Matcuk, G., 2017. The iliotibial tract: imaging, anatomy, injuries, and other pathology. Skeletal Radiology, 46(5), pp.605–622.
Foch, E., Reinbolt, J., Zhang, S., Fitzhugh, E. and Milner, C., 2015. Associations between iliotibial band injury status and running biomechanics in women.
Friede, M., Klauser, A., Fink, C. and Csapo, R., 2020. Stiffness of the iliotibial band and associated muscles in runner’s knee: Assessing the effects of physiotherapy through ultrasound shear wave elastography. Physical Therapy in Sport, 45, pp.126–134.
Geisler, P., 2020. Current Clinical Concepts: Synthesizing the Available Evidence for Improved Clinical Outcomes in Iliotibial Band Impingement Syndrome. Journal of Athletic Training, 56(8), pp.805–815.
Geisler, P. and Lazenby, T., 2017. Iliotibial Band Impingement Syndrome: An Evidence-Informed Clinical Paradigm Change. International Journal of Athletic Therapy and Training, 22(3), pp.1–11.
Grau, S., Krauss, I., Maiwald, C., Axmann, D., Horstmann, T. and Best, R., 2011. Kinematic classification of iliotibial band syndrome in runners. Scandinavian Journal of Medicine & Science in Sports, 21(2), pp.184–189.
Hamill, J., Miller, R., Noehren, B. and Davis, I., 2008. A prospective study of iliotibial band strain in runners. Clinical Biomechanics, 23(8), pp.1018–1025.
Hutchinson, L., Lichtwark, G., Willy, R. and Kelly, L., 2022. The Iliotibial Band: A Complex Structure with Versatile Functions. Sports Medicine, 52(5), pp.995–1008.
Louw, M. and Deary, C., 2013. The biomechanical variables involved in the aetiology of iliotibial band syndrome in distance runners — A systematic review of the literature.
Noble, C., 1979. The treatment of iliotibial band friction syndrome. British Journal of Sports Medicine, 13(2), pp.51–54.
Noehren, B., Schmitz, A., Hempel, R., Westlake, C. and Black, W., 2014. Assessment of Strength, Flexibility, and Running Mechanics in Men With Iliotibial Band Syndrome. Journal of Orthopaedic & Sports Physical Therapy, 44(3), pp.217–222.
Phinyomark, A., Osis, S., Hettinga, B., Leigh, R. and Ferber, R., 2015. Gender differences in gait kinematics in runners with iliotibial band syndrome. Scandinavian Journal of Medicine & Science in Sports, 25(6), pp.744–753.
Rosenthal, M., 2008. Clincal testing for extra-articular lateral knee pain. A modification and combination of traditional tests. North American Journal of Sports Physical Therapy, 3(2), pp.107–109.
Stickley, C., Presuto, M., Radzak, K., Bourbeau, C. and Hetzler, R., 2018. Dynamic Varus and the Development of Iliotibial Band Syndrome. Journal of Athletic Training, 53(2), pp.128–134.
Willett, G., Keim, S., Shostrom, V. and Lomneth, C., 2016. An Anatomic Investigation of the Ober Test. The American Journal of Sports Medicine, 44(3), pp.696–701.
Physiotutor Video (2020):
