The femur, commonly known as the thigh bone, is the longest and strongest bone in the human body. The greater trochanter is a prominent bony projection located on its upper part. This landmark serves as a crucial attachment point for various muscles, enabling a wide range of hip and leg movements and contributing significantly to overall mobility.
Understanding the Greater Trochanter
The greater trochanter is a large, irregular, quadrilateral-shaped bony eminence on the upper lateral aspect of the proximal femur. It projects superolaterally from the junction where the femoral neck meets the shaft, making it easily felt on the upper, outer side of the thigh.
The gluteus medius and gluteus minimus muscles, originating from the ilium, insert onto the lateral and anterior surfaces of the greater trochanter. These muscles are primarily responsible for abducting the thigh, moving the leg away from the body’s midline, and also contribute to medial rotation.
The piriformis muscle, a pear-shaped muscle located deep within the gluteal region, also inserts onto the superior aspect of the greater trochanter. The piriformis, along with other deep gluteal muscles like the obturator internus and gemelli, functions as a lateral rotator of the hip, turning the thigh outward. These muscle attachments allow the greater trochanter to act as a powerful lever arm, amplifying the force generated by the muscles to produce strong hip and leg movements. This mechanical advantage is important for activities such as walking, running, and maintaining balance.
Common Issues Affecting the Greater Trochanter
Pain and discomfort around the greater trochanter are common concerns, often stemming from conditions affecting the surrounding soft tissues. One frequent cause is trochanteric bursitis, which involves inflammation of the bursa sac located over the greater trochanter. This fluid-filled sac cushions the space between the bone and overlying tendons and muscles, but it can become irritated or damaged. Common causes include repetitive motions, such as prolonged standing, stair climbing, or cycling, as well as direct trauma or falls onto the hip.
Greater Trochanteric Pain Syndrome (GTPS) is a broader term encompassing trochanteric bursitis and other sources of lateral hip pain. GTPS often involves gluteal tendinopathy, which is the irritation or degeneration of the gluteus medius and gluteus minimus tendons where they attach to the greater trochanter.
While less common than other hip fractures, the greater trochanter can also sustain fractures. These injuries can occur from high-energy trauma in younger individuals, or low-energy trauma in older individuals due to weakened bones from osteoporosis. General symptoms include pain on the outside of the hip, tenderness to the touch over the greater trochanter, and pain that worsens with specific movements like walking, climbing stairs, or lying on the affected side.