**Figure 21.**

*(A) Angular stable plate and XS nail osteosynthesis and (B) alternating load test.*

will necessitate hemi or total shoulder arthroplasty, but the vast majority of fractures can be treated by osteosynthesis with multidirectional angular stability plates or other types of plates (**Figures 23** and **24**).

**Figure 22.** *Deformation values under load are higher for the plate than the XS nail.*

**Figure 23.** *Locked polyaxial plate for proximal humerus.*

**Figure 24.** *(A) Proximal humerus fracture type AO 11-B1 and (B and C) locked polyaxial plate fixation.*

The angular stable fixation of proximal humerus fractures has significantly improved the possibilities of anatomical reconstruction and postsurgical rehabilitation. Optimal screw positioning is hard to be achieved using classic T plates or monoaxial locked plates, especially in large bone defects or osteoporotic bones (**Figures 25** and **26**).

In a biomechanical study from 2006, the authors [43] compared on 18 sawbones the efficiency of osteosynthesis with multidirectional angular stability plate versus

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**Figure 26.**

**Figure 25.**

*Clinical and Experimental Biomechanical Studies Regarding Innovative Implants in Traumatology*

*(A) Proximal humerus fracture type AO 11-B3 and (B) fixation with polyaxial stability plate.*

monodirectional angular stability plate and normal (classic) T plate, with the same configuration and thickness. The bone-implant constructs were subjected to an alternating pressure load test of 1000 cycles between 50 and 200 N (**Figures 27** and **28**). After 1000 cycles, the total deformation was 0.7 mm in the PAS group, 1 mm in the MAS group, and 1.5 mm in the T-plate group. In all the tests, the highest resistance and the lowest deformation were seen in the polyaxial stability plate group.

*(A) Proximal humerus fracture type AO 11-B3 fracture and (B) fixation with polyaxial stability plate.*

*DOI: http://dx.doi.org/10.5772/intechopen.91728*

*Clinical and Experimental Biomechanical Studies Regarding Innovative Implants in Traumatology DOI: http://dx.doi.org/10.5772/intechopen.91728*

**Figure 25.** *(A) Proximal humerus fracture type AO 11-B3 and (B) fixation with polyaxial stability plate.*

**Figure 26.** *(A) Proximal humerus fracture type AO 11-B3 fracture and (B) fixation with polyaxial stability plate.*

monodirectional angular stability plate and normal (classic) T plate, with the same configuration and thickness. The bone-implant constructs were subjected to an alternating pressure load test of 1000 cycles between 50 and 200 N (**Figures 27** and **28**).

After 1000 cycles, the total deformation was 0.7 mm in the PAS group, 1 mm in the MAS group, and 1.5 mm in the T-plate group. In all the tests, the highest resistance and the lowest deformation were seen in the polyaxial stability plate group.

*Recent Advances in Biomechanics*

*Deformation values under load are higher for the plate than the XS nail.*

The angular stable fixation of proximal humerus fractures has significantly improved the possibilities of anatomical reconstruction and postsurgical rehabilitation. Optimal screw positioning is hard to be achieved using classic T plates or monoaxial locked plates, especially in large bone defects or osteoporotic bones

*(A) Proximal humerus fracture type AO 11-B1 and (B and C) locked polyaxial plate fixation.*

In a biomechanical study from 2006, the authors [43] compared on 18 sawbones the efficiency of osteosynthesis with multidirectional angular stability plate versus

**Figure 22.**

**Figure 23.**

*Locked polyaxial plate for proximal humerus.*

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**Figure 24.**

(**Figures 25** and **26**).

**Figure 27.**

*Sawbones with polyaxial angular stability (PAS) plate, monoaxial plate (MAS), or classic T plate (T).*

**Figure 28.**

*(A) No deformations at the PAS plate under load and (B) the closing of the osteotomy segment at T plate under load.*

In conclusion, the polyaxial angular stability plate offers not only an improved placement option for the screws but also a lower risk of reduction loss than the monoaxial plate or T plate [43].

## **8. Conclusions**

The authors enhance the advantages of these innovative implants for difficult clinical trauma cases. For supracondylar fractures simulated on plastic composite bones, DCS is better than CBP in most loading tests. In complex midshaft humeral fracture, the shorter locked plate (LCP—Synthes) seems to be the most rigid implant; the intramedullary nail proved to be the most elastic, while the DCP

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**Author details**

Paul-Dan Sirbu1

Andrei Scripcaru1

and Razvan Cosmin Tudor3

2 Rotkreuzklinik Wertheim, Germany

provided the original work is properly cited.

3 Vaslui County Hospital, Romania

\*, Wilhelm Friedl2

, Norin Forna1

\*Address all correspondence to: pdsirbu@yahoo.com

, Dan Mihailescu1

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

1 Grigore T. Popa University of Medicine and Pharmacy Iasi, Romania

, Mihnea Theodor Sirbu1

, Liliana Savin1

,

, Mihaela Pertea1

*Clinical and Experimental Biomechanical Studies Regarding Innovative Implants in Traumatology*

gives surprising values of torsion forces relatively close to the longer locked plate (AxSOS—Stryker). Clinical and biomechanical studies revealed the superiority of intramedullary gliding nail over DHS and gamma nail due to the double-T blade profile. The XS nail is a secure device for ankle and pilon fractures; in osteoporotic bone and difficult soft tissue conditions, it shows significant advantage over the plate fixation. In fractures of the patella and olecranon, the XS nail allows uniform compression of the fracture surface and overcomes the disadvantages of the AO tension band. Clinical and biomechanical tests proved the superiority of the polyaxial locked plates in distal radius and proximal humerus fractures due to the adjustable trajectory of the screws; in distal radius, the XS nail is stronger than the plates.

*DOI: http://dx.doi.org/10.5772/intechopen.91728*

### *Clinical and Experimental Biomechanical Studies Regarding Innovative Implants in Traumatology DOI: http://dx.doi.org/10.5772/intechopen.91728*

gives surprising values of torsion forces relatively close to the longer locked plate (AxSOS—Stryker). Clinical and biomechanical studies revealed the superiority of intramedullary gliding nail over DHS and gamma nail due to the double-T blade profile. The XS nail is a secure device for ankle and pilon fractures; in osteoporotic bone and difficult soft tissue conditions, it shows significant advantage over the plate fixation. In fractures of the patella and olecranon, the XS nail allows uniform compression of the fracture surface and overcomes the disadvantages of the AO tension band. Clinical and biomechanical tests proved the superiority of the polyaxial locked plates in distal radius and proximal humerus fractures due to the adjustable trajectory of the screws; in distal radius, the XS nail is stronger than the plates.
