Hip Bursitis

Hip bursitis involves inflammation of the fluid-filled sacs (bursae) that cushion the hip joint. The most commonly affected bursae are the trochanteric bursa (lateral hip) and iliopsoas bursa (anterior hip). However, true isolated bursitis is actually less common than previously thought.

What was traditionally called "trochanteric bursitis" is now understood to be primarily Greater Trochanteric Pain Syndrome (GTPS) - a gluteal tendinopathy affecting the gluteus medius and minimus tendons. For years, lateral hip pain was attributed to an inflamed bursa, and the presumed treatment was rest, ice, and anti-inflammatory injections. Research has shown that the primary issue is frequently not an inflamed bursa, but a distressed gluteus medius or minimus tendon. The bursa can become secondarily irritated, but it's rarely the main driver.

This distinction is crucial because treating a tendinopathy is not about rest and inflammation control; it's about managing load and progressively strengthening the tendon. True isolated bursitis typically occurs secondary to other conditions, direct trauma, or in rare cases, infection or inflammatory conditions. The bursa becomes inflamed due to mechanical irritation or repetitive friction, but this is usually part of a broader mechanical problem rather than an isolated inflammatory condition.

Bursae exist at locations where friction occurs between moving tissues - serving as fluid-filled cushions that reduce mechanical irritation. The trochanteric bursa sits between the iliotibial (IT) band and the greater trochanter bone, while the iliopsoas bursa sits between the iliopsoas tendon and the hip joint capsule or bony pelvis. Under normal circumstances, these bursae allow smooth gliding of these structures during hip movement. Inflammation develops when repetitive or excessive friction overwhelms the bursa's protective capacity.

For trochanteric bursitis, the mechanical problem involves the same compression forces discussed in Greater Trochanteric Pain Syndrome (GTPS). When your hip moves into adduction - bringing your thigh across your body's midline - the IT band tightens and compresses the trochanteric bursa against the greater trochanter. Positions that commonly create this compression include standing with weight shifted to one side, crossing your legs, and side-lying sleep postures where the top leg falls forward. Hip adduction substantially increases compressive load on the trochanteric bursa compared to neutral hip alignment.

Repetitive activities that involve hip abduction and adduction cycles create a "bow-stringing" effect where the IT band repeatedly slides over the greater trochanter, generating friction forces on the underlying bursa. Running, particularly on banked surfaces where one hip experiences more adduction than the other, creates thousands of friction cycles per mile. Repeated stance-phase loading generates shear and friction forces over the greater trochanter that can accumulate over time to irritate the underlying bursa.

The iliopsoas bursa experiences different mechanical stresses. This bursa sits at the front of the hip where the iliopsoas tendon crosses the brim of the pelvis and hip joint capsule. During hip flexion and extension movements - such as running, climbing stairs, or performing sit-ups - the iliopsoas tendon slides back and forth across the bursa. In individuals with tight hip flexors or those performing high volumes of hip flexion activities, this repetitive motion generates friction that can inflame the bursa. Runners performing high weekly mileage with inadequate hip flexor flexibility are at greater risk of iliopsoas bursa irritation than recreational runners.

Body positioning during sleep creates sustained compression on hip bursae that prevents overnight recovery. When lying on your side, direct pressure compresses the trochanteric bursa for hours at a time. This sustained compression impedes blood flow to the bursal tissues and prevents the normal inflammatory healing processes from occurring during sleep. Clinically, sustained side-lying compression on the affected hip is a recognised aggravating factor, with the mechanical stress of prolonged compression impeding recovery.

Muscle weakness, particularly of the hip abductors, creates abnormal loading patterns that increase friction forces on the bursae. When your gluteus medius is weak, the IT band and tensor fasciae latae must work harder to stabilize the pelvis during single-leg stance. This increased muscle tension translates to greater compression and friction forces on the trochanteric bursa. Hip abductor weakness is associated with increased IT band tension during walking compared to normal strength, contributing to greater bursal compression.