"Stress shielding of the proximal femur refers to local bone demineralisation due to the alleviation of normal weight-bearing stresses after hip arthroplasty. This is more common in non-cemented arthroplasties 4 . Some degree of radiographically evident stress shielding is common and clinically acceptable 1, but advanced cases can increase the risk of periprosthetic fracture 2."
"Grade 1 :represents mild proximal medial cortical changes, with rounding of the femoral neck."
"Grade 2 :shows more definite resorption of the medial cortex around the lesser trochanter."
"Grade 4 :represents extensive proximal cortical loss extending further into the femoral diaphysis."
"Grade 1 :represents mild proximal medial cortical changes, with rounding of the femoral neck."
"Grade 2 :shows more definite resorption of the medial cortex around the lesser trochanter."
"Grade 4 :represents extensive proximal cortical loss extending further into the femoral diaphysis."
"Pathophysiology"
"Risk factors"
"Imaging findings"
"Complications"
"Management"
"Reduced mechanical stimulus to the proximal femur"
"Progressive proximal bone remodelling and resorption"
"Redistribution of load towards the distal femur"
"Cementless femoral stems"
"Larger stem diameter"
"Greater stem stiffness"
"Low preoperative bone mineral density"
"Thin/atrophic femoral cortices"
"Older age"
"Higher body weight"
"Stem designs that transfer a greater proportion of load distally"
"Proximal femoral osteopenia"
"Reduction in cortical thickness"
"Resorption/rounding of the medial femoral neck or calcar"
"More pronounced changes in Gruen zones 1 and 7"
"Distal cortical hypertrophy may accompany proximal stress shielding"
"Grade 1 :represents mild proximal medial cortical changes, with rounding of the femoral neck."
"Grade 2 :shows more definite resorption of the medial cortex around the lesser trochanter."
"Grade 3 :the cortical resorption extends below the lesser trochanter"
"Grade 4 :represents extensive proximal cortical loss extending further into the femoral diaphysis."
Expected headings
"Pathophysiology"
"Risk factors"
"Imaging findings"
"Plain radiograph"
"Complications"
"Management"
"The degree of stress shielding is influenced by the stiffness, geometry and fixation characteristics of the femoral stem as well as the patient’s pre-existing bone quality."
"Severe or progressive bone loss with implant loosening, fracture or significant symptoms may require revision arthroplasty"