Other Hip Disorders

Avascular necrosis of the femoral head, and labral tears / femoroacetabular impingement (FAI).

Avascular necrosis (AVN) of the femoral head

• Demographics: 20–50 yrs (average ~38). Often follows subcapital fracture (~40% progress to AVN) or untreated SCFE/Perthes.
• Risk factors: corticosteroid use, SLE, sickle cell disease, past hip fracture/dislocation, pregnancy, alcoholic liver disease.
• History: deep groin/hip pain; patients can often still walk.
• Examination: pain especially on internal rotation; limited ROM; antalgic gait.
• Investigations: X-ray first; MRI is the modality of choice if X-ray is normal (detects early disease).
• Management: orthopaedic referral — usually needs surgery; conservative measures while waiting (beware falls and thrombotic events from reduced activity). See also osteonecrosis for the general condition at other sites.

Labral tears & femoroacetabular impingement (FAI)

• Demographics: any age; commonly active females, dancers/athletes, and after motor vehicle accidents.
• History: sharp impingement pain in the hip or groin with painful clicking, catching or locking.
• Examination:
  • FADIR impingement test — supine, hip at 90° flexion and maximal internal rotation, then adduct: pain suggests intra-articular pathology such as a labral tear.
  • Patrick (FABER) test — distinguishes hip (anterior/groin pain → FAI) from SIJ (posterior pain) — see sacroiliac dysfunction.
• Investigations: X-ray first to exclude bony pathology; MRI is the investigation of choice; hip arthroscopy is also diagnostic.
• Management: unclear — refer to orthopaedics if suspected. Hip arthroscopic surgery is not proven effective for labral tears but is the main option available.