Does cam osteochondroplasty compromise proximal femur strength?

Area of Science:

• Orthopedic biomechanics
• Surgical outcomes research

Background:

• Femoral acetabular impingement (FAI) is a common cause of hip pain.
• Osteochondroplasty is a surgical procedure to address FAI.
• The impact of osteochondroplasty volume on femoral load-bearing capacity is not well understood.

Purpose of the Study:

• To evaluate the effect of varying osteochondroplasty resection volumes on the load-bearing ability of cam-type femurs.
• To compare the deformation of dry-bone femur models after different surgical resection volumes.

Main Methods:

• Ten dry-bone replicas of cam-type femurs (cam A and B) underwent three increasing volumes of resection (conservative, adequate, radical).
• Deformation was measured under cyclic loading (700 N for five cycles) after each resection stage.
• Surgical efficacy was assessed using the 360° alpha angle and changes in the head-to-neck ratio.

Main Results:

• Conservative resection (Surgery I) significantly reduced axial displacement in cam A models and all resections in cam B models.
• Radical resections (Surgery III) in cam A models led to increased axial displacement compared to controls.
• Intermediate resections (Surgery II) showed no significant change in displacement for cam A models.

Conclusions:

• Conservative osteochondroplasty may enhance the axial load-bearing capacity of cam-type femurs.
• Extensive bone resection during osteochondroplasty can compromise the fracture-resistant properties of the femur.
• Surgical planning should consider the potential biomechanical consequences of resection volume.