Surgical Fixation of Calcaneal Beak Fractures- Biomechanical Analysis of Different Osteosynthesis Techniques

SLR - November 2023 - Patel

Title: Surgical Fixation of Calcaneal Beak Fractures- Biomechanical Analysis of Different Osteosynthesis Techniques  

Reference: Jordan MC, Hufnagel L, McDonogh M, et al. Surgical Fixation of Calcaneal Beak Fractures-Biomechanical Analysis of Different Osteosynthesis Techniques. Front Bioeng Biotechnol. 2022;10:896790. Published 2022 Aug 4. doi:10.3389/fbioe.2022.896790Level of Evidence 

Level of Evidence: Level III 

Scientific Literature Review 

Reviewed By: Neathie Patel 

Residency Program: East Liverpool City Hospital- East Liverpool, Ohio 

Podiatric Relevance: With multiple methods of fixation available, it is difficult to determine which method of fixation is the most resilient to stress, provides best anatomic alignment and is the most cost effective for addressing calcaneal beak fracture fixation. The authors aim to model multiple methods of fixation of calcaneal beak fractures and their strength in a cadaveric model in an attempt to help elucidate the most reliable technique of fixation of a calcaneal beak fracture.  

Methods: 50 synthetic bone specimen of the calcaneus were fractures in a Beavis Type II fracture pattern using an oscillating saw. A braided synthetic knot was attached to the calcaneus to simulate the Achilles tendon. The specimen was mounted in a fixation device to stimulate weight bearing. 5 groups were tested: 2 6.5 mm cannulated screws with a washer, 2 cannulates 4.0 mm screws and a washer, 2 headless cannulated 5.0 mm Screws 2.3 mm plate fixation, and 2.8 mm plate fixation. A 10 N preload was followed by 10 setting cycles between 10 and 40 N. This was followed by cyclic loading from 10 to 100 N for 1000 cycles and the final load level was 10-1300 N for 1,000 load repeats. A static ultimate strength test was performed after cyclic testing to measure load failure and failure mode. Peak to Peak displacement, stiffness, plastic deformation, total displacement, and load to failure and mode of failure were tested.  

Results: The plates were not able to bear 200 and 300 N tension. There was a significant different between 2 6.5 cannulated screws and a washer, 2.0 mm Cannulated screws and 2 5.0 mm headless cannulated screw group in peak to peak displacement, total displacement. There was no significant difference in plastic deformation and stiffness for the 100 N load level but a significant difference between the 2 6.5 mm cannulated screw and washer and the 2 4.0 mm screw and washer group at 200 and 300 N. There was no significant difference found in maximal load to failure between the three groups. 

Conclusions: The authors concluded that 6.5 mm partially threaded screws and 5.0 mm headless cannulated compression screws have the best overall stability but 2 4.0 mm partially threaded screws area a good alternative. 2.3-mm and 2.8 mm bend plates are note recommended however, if they are used, fixation should be reinforced with anchors or other fixation techniques. Screw cut out is a mode of Failure in partially threaded screws with fragment pull out occurring in 5.0 mm headless cannulated compression screws and with plates. As well as being less invasive and technically less difficult to perform, screw fixation provides a superior method of fixation of and should be therefore be adopted as surgical fixation of calcaneal beak fracture.