**5. Locked intramedullary XS nail for ankle and pilon fractures: design, biomechanics, and clinical results**

Fractures around the ankle are very frequent injuries, and the aim of the treatment is reconstruction of the anatomy with stable and minimally invasive osteosynthesis techniques [22, 23] while avoiding further trauma of soft tissue in a local region with anatomical peculiarities: the skin is thin, with limited mobility, with almost nonexistent skin excess, a very poorly represented subcutaneous soft tissue, and poor blood supply [24, 25].

Plate osteosynthesis is the "gold standard" procedure for distal fibula, pilon, and lower leg fractures, but Zaghloul et al. reported a rate of 21.5% complications, with 2% infections and 10.8% operative revisions [26].

The severe wound complications associated with an extramedullary implant due to the compromised blood supply (arterial occlusion diseases, diabetes, and postthrombotic sequels) and the thin soft tissue envelope require removal of the plate (with secondary stability impairment) and additional challenging reconstructive technical solutions including split-thickness skin grafts and local or locoregional flaps [27–29]. With regard to the use of split-thickness skin grafts, they are often impossible to use in the case of soft part defects in the ankle, due to bone or tendinous exposure. Lately, a solution worthy of consideration is the use of negative pressure therapy, so that a good, vascularized bed can be created, which will allow the use of a split-thickness skin graft (**Figure 9**).

Intramedullary implants had biomechanical advantages over plates by reducing the lever arm and increasing the stability of the construct [27, 30]. The limitations of simple wires, intramedullary pins, and distally locked flexible nails,

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**Figure 7.**

*(A) AO/OTA A3.3 pertrochanteric fracture and (B) osteosynthesis with gliding nail.*

The double-T profile has a higher stiffness due to its rotational stability and due to its reduced risk of damage in osteoporotic bone. The nail curvature of 6° in frontal plane and straight in sagittal plane allows the entry point on the tip of the trochanter (thus having a lower risk of circulatory disorders to the femoral head

*(A) Axial view of the double-T blade profile inside the femoral head (sawbone); (B) lateral view of the GN in* 

Another important characteristic is the dynamic impaction possibility in the femoral neck direction with dynamic stability in the femoral shaft direction

The first study from 1996 [18], which compared the gliding nail system with the gamma nail, showed better intraoperative and postoperative results for the GN. The rate of intraoperative complications for the GN was 2.7%, while for the gamma nail, it was between 17.2 and 42.2%. The difference in outcome is highlighted by the longterm results, where the gliding nail had only 3.9% rate of complications, while the

Following the promising results, a biomechanical study from 1998 showed the importance of the blade geometry for the stability of fixation in proximal femoral fractures. The alternating load examinations on Sawbone femoral heads revealed no instability of the implant after 100,000 cycles at a load of 2000 N. The displacement of the double-T blade after 1000 cycles at 1500 N was 1–4 mm, while for the

than opening the piriformis fossa) (**Figure 7**).

*three sizes; and (C) 3D view of the gliding nail.*

10 mm, screw of the gamma nail was 4–8 mm [19].

(**Figure 8**).

**Figure 6.**

gamma nail had 6–13.8% [18].

#### **Figure 9.**

*Wound complication after fibular plate osteosynthesis; (A) necrosis and exposure of the osteosynthesis material; (B) soft tissue defect after debridement; (C) granular bed after negative pressure therapy; and (D) granular bed covered with skin graft.*

regarding no maintenance of length and rotation, prompted the surgeons to look for alternative techniques for osteosynthesis; the crucial requirements were minimally invasive approaches with less soft tissue irritation and high biomechanical stability. When a soft tissue problem occurs, the treatment is much easier because there is no implant on the bone surface, so that only excision and split skin graft can be performed.

From 1999, some investigators in Germany [27, 30] started to use a novel intramedullary cannulated small-diameter straight locked nail system for the fibula osteosynthesis, which was primarily designed for the treatment of fractures under tension: the XS nail. The intramedullary device length was improved to the needs of the fibula osteosynthesis (**Figure 10**). The advantages of this nail allowed their use for fractures of the fibula and tibial pilon.

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**Figure 11.**

*wires; and (5) cross-locking threaded K wire.*

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

The XS(L) nail used in the treatment of malleolar fractures has a rounded figure and a width varying from 4.5 to 3.5 mm in the case of XXS(L) nail [27, 28, 30]. The type of fracture dictates the number of locking holes needed, with an availability between 4–11 spaced (9 mm) locking holes and 3, 4, 6, 8, or 10 locking holes for the smaller XXS(L) nail (**Figure 11**). Two holes closest to the fixation have a longitudinal oval alignment. For XSL long nails, there are available lengths of up to 272 mm,

Before starting with the clinical application of this innovative implant, experimental tests were performed comparing a standard plate and compression screw

Eighteen sawbones were used to create Weber type B, type C, and suprasyndesmotic fractures by resection osteotomy. In each group, three sawbones were "treated" by plate and compression screw, and three with XS nail. Load was applied in 1000 cycles of 40–100 N with a frequency of 1 Hz using a MTS® machine (www. mts.com). Both plastic and total deformations were recorded. The tests showed that

Based on these promising results, from May 2000 to January 2002, the surgeon designers operated 194 ankle joint fractures (one-third bimalleolar injuries) using the innovative XS nail [27, 30]. The results (according to Olerud score) were

encouraging (excellent outcome—58.6%, a good one—33.3%, a fair one—5.5%, and an unsatisfactory outcome—2.5%), with very few soft tissue problems and only one

The nail insertion is realized after open fracture reduction in displaced ankle fractures (**Figure 12**) and percutaneously for pilon and lower leg fractures (with extraarticular involvement) [27, 28, 30]. The preoperative planning is crucial including the analysis of diameter of the medullary canal up to the optimal level of stabilization. XS nail is not indicated in rare cases when the canal is too narrow, and for a very thin medullary space, the XXS nail should be used. It is essential that the medullary canal must have a diameter of at least 3 mm in case of XS nail osteosynthesis [27, 28, 30]. The nail insertion requires the division of the retinaculum distal

*Standard XS nail with aiming device: (1) X-ray transparent carbon aiming device; (2) XS standard (4–5 mm) nail, here 12-hole nail; (3) adapter for the nail on the aiming device; (4) lateral drill sleeve for the locking* 

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

and 197 mm for the XXSL nails [28].

nonunion.

with the XS nail in fibula osteotomies [27, 31].

the nail group showed a lower deformation and higher stability.

to the fibula and retraction of the peroneal tendons.

**Figure 10.** *Ankle fracture before and after XS nail osteosynthesis.*

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

The XS(L) nail used in the treatment of malleolar fractures has a rounded figure and a width varying from 4.5 to 3.5 mm in the case of XXS(L) nail [27, 28, 30]. The type of fracture dictates the number of locking holes needed, with an availability between 4–11 spaced (9 mm) locking holes and 3, 4, 6, 8, or 10 locking holes for the smaller XXS(L) nail (**Figure 11**). Two holes closest to the fixation have a longitudinal oval alignment. For XSL long nails, there are available lengths of up to 272 mm, and 197 mm for the XXSL nails [28].

Before starting with the clinical application of this innovative implant, experimental tests were performed comparing a standard plate and compression screw with the XS nail in fibula osteotomies [27, 31].

Eighteen sawbones were used to create Weber type B, type C, and suprasyndesmotic fractures by resection osteotomy. In each group, three sawbones were "treated" by plate and compression screw, and three with XS nail. Load was applied in 1000 cycles of 40–100 N with a frequency of 1 Hz using a MTS® machine (www. mts.com). Both plastic and total deformations were recorded. The tests showed that the nail group showed a lower deformation and higher stability.

Based on these promising results, from May 2000 to January 2002, the surgeon designers operated 194 ankle joint fractures (one-third bimalleolar injuries) using the innovative XS nail [27, 30]. The results (according to Olerud score) were encouraging (excellent outcome—58.6%, a good one—33.3%, a fair one—5.5%, and an unsatisfactory outcome—2.5%), with very few soft tissue problems and only one nonunion.

The nail insertion is realized after open fracture reduction in displaced ankle fractures (**Figure 12**) and percutaneously for pilon and lower leg fractures (with extraarticular involvement) [27, 28, 30]. The preoperative planning is crucial including the analysis of diameter of the medullary canal up to the optimal level of stabilization. XS nail is not indicated in rare cases when the canal is too narrow, and for a very thin medullary space, the XXS nail should be used. It is essential that the medullary canal must have a diameter of at least 3 mm in case of XS nail osteosynthesis [27, 28, 30]. The nail insertion requires the division of the retinaculum distal to the fibula and retraction of the peroneal tendons.

#### **Figure 11.**

*Standard XS nail with aiming device: (1) X-ray transparent carbon aiming device; (2) XS standard (4–5 mm) nail, here 12-hole nail; (3) adapter for the nail on the aiming device; (4) lateral drill sleeve for the locking wires; and (5) cross-locking threaded K wire.*

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**Figure 10.**

can be performed.

*bed covered with skin graft.*

**Figure 9.**

*Ankle fracture before and after XS nail osteosynthesis.*

for fractures of the fibula and tibial pilon.

regarding no maintenance of length and rotation, prompted the surgeons to look for alternative techniques for osteosynthesis; the crucial requirements were minimally invasive approaches with less soft tissue irritation and high biomechanical stability. When a soft tissue problem occurs, the treatment is much easier because there is no implant on the bone surface, so that only excision and split skin graft

*Wound complication after fibular plate osteosynthesis; (A) necrosis and exposure of the osteosynthesis material; (B) soft tissue defect after debridement; (C) granular bed after negative pressure therapy; and (D) granular* 

From 1999, some investigators in Germany [27, 30] started to use a novel intramedullary cannulated small-diameter straight locked nail system for the fibula osteosynthesis, which was primarily designed for the treatment of fractures under tension: the XS nail. The intramedullary device length was improved to the needs of the fibula osteosynthesis (**Figure 10**). The advantages of this nail allowed their use

**Figure 12.**

*XS nail osteosynthesis for a left distal fibula fracture; (A and B) preoperative X-rays; (C and D) postoperative X-rays; (E) insertion of the guiding wire; (F) insertion of the nail with the aiming device; and (G) locking with transfixing threaded wires.*

After open reduction of distal fibular fracture and compression with a reduction forceps, a guide wire (1.6–2 mm thickness) is inserted under fluoroscopic control in the medullary canal. The position of the wire is verified in two radiological views, and a cannulated drill is used to the desired length of the nail, using the same diameter. The best stability is obtained by placing a nail, which is at least 2.7 cm (3 holes) longer than the fracture site.

A crucial step is to choose the biggest nail diameter fitting into the medullary canal, in order to obtain the stability of the syndesmosis without fibulotibial set screw [27, 28].

The radiolucent aiming device is used to place the nail tightly in the canal, and afterward, cross-locking is realized with threaded K wires at 90°; 2.4 or 2.0 mm wires are used depending on the type of nail (XS or XXS). Maximum stability is obtained by securing the nail with two proximal and two distal wires. The hole diameter is 0.2 mm smaller and ensures an angle stable locking for the wires. Additional interfragmentary compression can be achieved in transverse or short oblique fracture by placing a compression screw after the removal of the aiming device. For oblique or comminuted fracture, the compression realized with reposition forceps can be preserved by threaded wires that cross the fracture site [27, 28, 30]. In type C fractures, with a larger medullar canal than the nail diameter, an additional fibulotibial set screw must be used in order to ensure a stable syndesmosis [28].

At the end of the surgery, the threaded wires are cut with a special device, in order to minimize the implant over the bone surface.

The XS nail can additionally be used in percutaneous technique for concomitant fractures of the fibula in distal metaphyseal fractures of the lower leg, pilon fractures and for fixation of the tibia following joint reconstruction [28, 32, 33]. A perfect anatomical reduction of the fibula is not needed, so no additional damage will compromise the thin soft tissue and impaired blood supply (**Figure 13**).

The percutaneous osteosynthesis with an XS nail is first performed for the fibular fracture and then tibia is fixed with one XS nail introduced from the medial malleolus to the proximal lateral cortical bone; if it is necessary, a second XS nail is inserted from the distal lateral tibia aiming at the proximal medial cortical bone [28, 32, 33].

The minimally invasive osteosynthesis of pilon fracture using the XS nail, as well as the absence of plates on the bone surface, reduces significantly the healing problems and the rate of complication for these difficult fractures [33].

All the clinical and biomechanical studies enhanced that XS and XXS nails are important alternatives to classic plate osteosynthesis for distal fibula, pilon, or

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**Figure 14.**

*nail osteosynthesis.*

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

lower leg fractures while avoiding soft tissue complications and ensuring a stable

**6. The XS nail for the treatment of fractures under tension: patella** 

These advantages highlight the XS nail as an "ideal" implant for patients with poor bone and soft tissue healing problems due to vascular conditions, diabetes, or trauma.

In patella fractures, the surgical treatment with the AO tension belt osteosynthesis system is the golden standard today, but the results are not always good on the long term. Dislocation and functional deficit (limited mobility) can be as high as

One explanation is that the tendon insertions and the retinaculum create a gap between the tension-band wires and the bone, thus a very tight fixation cannot be

Moreover, due to the fact that the AO tension band is placed on the anterior surface of the patella, there is a distraction in the fracture site on the articular surface, which causes fracture gaps, dislocations, nonunion, and finally implant failure (**Figure 14**).

*(A and B) AO 34-C1 fracture of the patella; (C and D) internal fixation with tension band and cerclage wire; (E and F) failure of the construct tension band and cerclage wire; and (G and H) revision surgery with XS* 

fracture fixation with a higher weight bearing tolerance.

*Distal metaphyseal lower leg fracture and XS nail osteosynthesis.*

achieved; because of this, loosening occurs after loading [35].

**and olecranon**

**Figure 13.**

20–50% of all cases [34].

*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 13.**

*Recent Advances in Biomechanics*

(3 holes) longer than the fracture site.

screw [27, 28].

**Figure 12.**

*with transfixing threaded wires.*

After open reduction of distal fibular fracture and compression with a reduction forceps, a guide wire (1.6–2 mm thickness) is inserted under fluoroscopic control in the medullary canal. The position of the wire is verified in two radiological views, and a cannulated drill is used to the desired length of the nail, using the same diameter. The best stability is obtained by placing a nail, which is at least 2.7 cm

*XS nail osteosynthesis for a left distal fibula fracture; (A and B) preoperative X-rays; (C and D) postoperative X-rays; (E) insertion of the guiding wire; (F) insertion of the nail with the aiming device; and (G) locking* 

A crucial step is to choose the biggest nail diameter fitting into the medullary canal, in order to obtain the stability of the syndesmosis without fibulotibial set

The radiolucent aiming device is used to place the nail tightly in the canal, and afterward, cross-locking is realized with threaded K wires at 90°; 2.4 or 2.0 mm wires are used depending on the type of nail (XS or XXS). Maximum stability is obtained by securing the nail with two proximal and two distal wires. The hole diameter is 0.2 mm smaller and ensures an angle stable locking for the wires. Additional interfragmentary compression can be achieved in transverse or short oblique fracture by placing a compression screw after the removal of the aiming device. For oblique or comminuted fracture, the compression realized with reposition forceps can be preserved by threaded wires that cross the fracture site [27, 28, 30]. In type C fractures, with a larger medullar canal than the nail diameter, an additional fibulotibial set

At the end of the surgery, the threaded wires are cut with a special device, in

The XS nail can additionally be used in percutaneous technique for concomitant fractures of the fibula in distal metaphyseal fractures of the lower leg, pilon fractures and for fixation of the tibia following joint reconstruction [28, 32, 33]. A perfect anatomical reduction of the fibula is not needed, so no additional damage will compromise the thin soft tissue and impaired blood supply (**Figure 13**). The percutaneous osteosynthesis with an XS nail is first performed for the fibular fracture and then tibia is fixed with one XS nail introduced from the medial malleolus to the proximal lateral cortical bone; if it is necessary, a second XS nail is inserted from the distal lateral tibia aiming at the proximal medial cortical bone

The minimally invasive osteosynthesis of pilon fracture using the XS nail, as well as the absence of plates on the bone surface, reduces significantly the healing

All the clinical and biomechanical studies enhanced that XS and XXS nails are important alternatives to classic plate osteosynthesis for distal fibula, pilon, or

problems and the rate of complication for these difficult fractures [33].

screw must be used in order to ensure a stable syndesmosis [28].

order to minimize the implant over the bone surface.

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[28, 32, 33].

*Distal metaphyseal lower leg fracture and XS nail osteosynthesis.*

lower leg fractures while avoiding soft tissue complications and ensuring a stable fracture fixation with a higher weight bearing tolerance.

These advantages highlight the XS nail as an "ideal" implant for patients with poor bone and soft tissue healing problems due to vascular conditions, diabetes, or trauma.
