Who Wants to be IT: An Underappreciated Cause of Lateral Thigh Pain and Paresthesias

The IT band is a taut fibrous band that is a continuation of the tensor fascia latae (TFL) and attaches to the hip abductors and vastus lateralis.1 Distally, it spans to the lateral border of the patella and onto Gerdy’s tubercle.1 It assists with hip abduction and is an antagonist with TFL for controlling hip adduction during gait.1 It slides over the lateral femoral condyle at 30° of knee flexion and when taut causes friction and irritation.1 TFL and hip abductor dysfunction are associated with ITBS.1 Simons et al. described radiating patterns of pain and paresthesias of TFL trigger points that extend over the lateral thigh, overlapping with the lateral femoral cutaneous nerve (LFCN) territory.2 While the mechanism is unclear, there is an increasing understanding that myofascial pain can cause paresthesia and dysesthesia, thus mimicking a true neurogenic pain generator.3 While meralgia paresthetica can present distinctly from ITBS, it may co-exist with other causes of lateral thigh pain and paresthesia, including ITBS.4 The IT band also overlies the greater trochanter, which has discrete bursae that serve to cushion tendinous attachments.5 Inflammation of the greater trochanteric area elicits pain and often burning, extending along the length of the lateral thigh with highest concentration at the greater trochanter5 mimicking the geographic pattern of meralgia paresthetica. When assessing patients with lateral thigh paresthesias, it is paramount to palpate for greater trochanteric tenderness, perform modified Thomas test for hip flexor tightness, as well as Ober’s and Noble’s tests to confront the IT band’s tautness.1,10 These tests are especially important when sensory examination disturbance is not well demarcated to the exact LFCN distribution, which would remain persistent and well circumscribed in meralgia paresthetica. [...]identifying the correct or even concurrent diagnoses is important for patient outcome.