Perren built a strain-gauge load-cell plate to continuously measure axial compression in living cortical bone over weeks. The study asks whether static compression under rigid internal fixation causes pressure necrosis and how compression changes over time. It then applies this to a new titanium Dynamic Compression Plate.
The core teaching point: compression under a plate is not permanent, and that is fine. Static compression of 60-140 Kp does not cause pressure necrosis. Instead compression fades over 3-5 months as Haversian remodelling replaces the compressed osteons. This is the mechanism behind primary (direct) bone healing.
The decisive detail for boards is sensitivity: a 10-20 micron loss of bone would abolish compression instantly. Since no sudden pressure drop ever occurred, the fixation stayed rigid and the interfaces never resorbed. Sudden pressure loss would signal instability or necrosis.
This is why we chase absolute stability for direct healing. Motion, which is intermittent pressure reaching zero, does induce resorption. The counterpoint is stress protection: rigid plates shield the cortex, causing osteoporosis and later fatigue fracture, which motivated the lower-modulus titanium DCP.
Perren built a strain-gauge load-cell plate to continuously measure axial compression in living cortical bone over weeks. The study asks whether static compression under rigid internal fixation causes pressure necrosis and how compression changes over time. It then applies this to a new titanium Dynamic Compression Plate.
The core teaching point: compression under a plate is not permanent, and that is fine. Static compression of 60-140 Kp does not cause pressure necrosis. Instead compression fades over 3-5 months as Haversian remodelling replaces the compressed osteons. This is the mechanism behind primary (direct) bone healing.
The decisive detail for boards is sensitivity: a 10-20 micron loss of bone would abolish compression instantly. Since no sudden pressure drop ever occurred, the fixation stayed rigid and the interfaces never resorbed. Sudden pressure loss would signal instability or necrosis.
This is why we chase absolute stability for direct healing. Motion, which is intermittent pressure reaching zero, does induce resorption. The counterpoint is stress protection: rigid plates shield the cortex, causing osteoporosis and later fatigue fracture, which motivated the lower-modulus titanium DCP.