Orthopaedics: Hip

Hip

Hip Fracture

General Features

·                 acute onset of hip pain

·                 unable to weight-bear

·                 shortened and externally rotated leg

·                 painful ROM

Arthritis of the Hip

Etiology

·                 osteoarthritis (OA), inflammatory arthritis, post-traumatic arthritis, late effects of congenital hip disorders or septic arthritis

Clinical Features

·                 pain (groin, medial thigh) and stiffness aggravated by activity

·                 morning stiffness, multiple joint swelling, hand nodules (RA)

·                 decreased ROM (internal rotation is lost first)

·                 crepitus

·                 ± fixed flexion contracture leading to apparent limb shortening (Thomas test)

·                 ± Trendelenberg sign

Investigations

·                 x-ray

o       OA: joint space narrowing, subchondral sclerosis, subchondral cysts, osteophytes

o       RA: osteopenia, joint space narrowing, subchondral cysts

·                 bloodworic ANA, RF

Treatment

·                 conservative: weight reduction, activity modification, PT, analgesics, walking aids

·                 operative: realign = osteotomy; replace = arthroplasty; fuse = arthrodesis

·                 complications with arthroplasty: component loosening, dislocation, heterotopic bone formation, thromboembolus, infection, neurovascular injury

·                 arthroplasty is standard of care in most patients with hip arthritis

Hip Dislocation after THA

Etiology

·                 total hip arthroplasty (THA) that is unstable when hip is flexed, adducted and internally rotated or extended and externally rotated (avoid flexing hip >90 degrees or crossing legs for approximately 6 weeks after surgery)

Epidemiology

·                 occurs in 1-4% of primary THA and 10-16% of revision THAs

·                 risk factors: neurological impairment, post-traumatic arthritis, revision surgery, substance abuse

Treatment

·                 external abduction splint to prevent hip adduction

·                 constrained acetabular component for recurrent dislocation if no issue with position of acetabular/femoral implants

Complications

·                 sciatic nerve palsy in 25% (10% permanent)

·                 heterotopic ossification (HO)