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Impact-absorbing properties of the human knee
1Queen's Medical Centre, Nottingham, England.
The Journal of Bone and Joint Surgery. British Volume
|November 1, 1987
Summary
This study reveals knee joints absorb impact through multiple structures. Damage or removal of these structures, including knee replacements, significantly increases transmitted force, potentially causing bone damage.
Area of Science:
- Orthopedics
- Biomechanics
- Biomedical Engineering
Background:
- The knee joint's natural load-absorbing mechanisms are crucial for joint health.
- Osteoarthritis and knee replacements can alter these mechanisms, impacting joint function and longevity.
Purpose of the Study:
- To biomechanically investigate the impact load-absorbing capacity of the knee joint.
- To quantify force transmission through intact, damaged, and replaced knee joints.
Main Methods:
- Utilized 20 cadaveric knees for biomechanical testing.
- Applied impact loads to the proximal femur and measured transmitted forces at the distal tibia via a load transducer.
- Sequentially damaged or removed knee structures (meniscus, cartilage, bone) and tested implanted knee replacements.
Main Results:
- Peak transmitted force increased with sequential damage or removal of the meniscus, articular cartilage, and subchondral bone.
- Implanted knee replacements transmitted 180% more force than intact knees.
- Osteoarthritic knees exhibited reduced shock absorption compared to normal knees.
Conclusions:
- Each segment of the knee joint contributes to impact absorption.
- Damage to natural structures or implantation of prosthetics compromises the knee's shock-absorbing ability.
- Elevated forces in replaced knees may lead to cancellous bone microfractures and loosening.