Mechanical factors explain development of cam-type deformity

Area of Science:

• Biomechanics
• Skeletal Biology
• Osteoarthritis Research

Background:

• Cam-type deformity significantly elevates the risk of hip osteoarthritis (OA).
• This skeletal anomaly is more common in young, active adults.
• Mechanical loading during physical activities may contribute to cam-type deformity formation.

Purpose of the Study:

• To investigate if mechanical factors during adolescence stimulate cam-type deformity development.
• To determine if growth plate shape influences the impact of mechanical factors on cam-type deformity.
• To explore mechanobiological mechanisms underlying cam-type deformity and hip OA.

Main Methods:

• Utilized finite element (FE) models of the proximal femur with an open growth plate.
• Simulated four distinct loading conditions representing various physical activities.
• Assessed three growth plate extension levels towards the femoral neck.
• Calculated the osteogenic index (OI) to quantify mechanical stimuli at the tissue level.

Main Results:

• Both loading conditions and growth plate shape affect the distribution of the osteogenic index (OI) in open growth plates.
• Specific physical activity-related loads and greater growth plate extension towards the femoral neck increase cam-type deformity likelihood.
• Mechanical stimuli distribution is a key factor in cam-type deformity development.

Conclusions:

• Specific loading patterns appear to promote cam-type deformity by altering mechanical stimulus distribution.
• Findings align with recent clinical observations and elucidate the mechanobiology of cam-type deformity.
• Avoiding certain loading patterns during skeletal growth could be a preventative strategy for hip OA.