- Referred pain from back and pelvis to the hip like lumbar radiculopathy, pelvic diseases, ovarian problems, and hernias.
- Primary Tissue disorders
a. Bone – AVN, bone marrow edema, tumors, infections, fractures
b. Cartilage – skeletal dysplasias, chondropathy
c. Synovium – synovitis, rheumatological diseases.
d. Neuromuscular – muscular dystrophy, myopathy, neuropathy
- Morphological variations of the femur and acetabulum causing pain with movements (Mechanical hip pain). Morphology and mechanics often go together. Most morphological variations are well compensated and do not cause any problem until one of the following essential requirements of good hip function are affected. Risk factors for each are
1.Good articular cartilage surface – osteochondral defects, foveal loading, loose bodies
2. Stable femoral head – acetabular dysplasia, coxa valga, version changes, impingement induced instability
3.Impingement free motion – coxa vara, breva, plana, magna, aspherical head, protrusio, retroversion, overgrown GT, LT, AIIS
4.Adequate motor control – coxa vara, breva, version problems, snapping over bone prominence, strains secondary to hip stiffness
Almost all the morphological variations are visible on plain x-rays. Clinical examination is often adequate to understand their role in causing pain. CT, MRI, and diagnostic injections can be used when necessary. Activity modification decreases mechanical pain. Goal of elective surgical treatment is to relieve pain and improve function by correcting the likely causes. Labral tears are secondary to dysplasia and impingement and are addressed as needed.