VOLT™ Mini Fragment and VOLT Small Fragment Plating Systems
Fig 1: VOLT™ Mini and Small Fragment Plating System Overview. Developed by the Next Generation Plating Task Force of the AO Technical Commission in collaboration with Johnson & Johnson MedTech, the Variable Angle Optimized Locking Technology (VOLT™) Mini and Small Fragment Plating Systems are instrument and implant sets intended for the internal fixation of bones and bone fragments of the appendicular skeleton appropriate for the implant size. The main objective of the Task Force was to create a robust system with exceptional locking performance and stability for a wide range of implant shapes and sizes in both stainless steel and titanium.
The VOLT™ system features new variable angle locking technology while maintaining the proven Dynamic Compression Unit (DCU). It delivers the stability of the Locking Compression Plate (LCP) system and the flexibility of the Variable Angle Locking Compression Plate (VA-LCP) system. The VOLT™ System includes mini (2.0 mm, 2.4 mm, and 2.7 mm) and small (3.5 mm, and 4.0 mm) fragment generic plates and VA locking, cortex, and cancellous screws (Figs 1–4) as well as instruments for open reduction and internal fixation of bone fragments.
VOLT™ implants are available in stainless steel and titanium in all sizes.
System description
Both the Mini Fragment and Small Fragment Plating Systems are intended for adults, children (2–12 years), and adolescents (12–21 years) in which growth plates (physes) have fused, or in which unfused growth plates will not be compromised by fixation.
The indication is such that the plating systems support auxiliary plating techniques and education. Instructions for use and surgical technique are available from Johnson & Johnson MedTech with details of indications, contraindications, side effects, warnings, and precautions.
Fig 2: Overview of the VOLT Mini Fragment generic plates. Note: The Quarter Tubular Plate is an existing non-locking plate, not a new VOLT plate. The new plates are designed to offer various options regarding plate shape and profile as well as hole density appropriate to different fracture patterns. The instrument functionality has been improved and a consistent look and feel has been implemented to ensure ease of use.
The Mini Fragment and Small Fragment Plating Systems are designed in a modular way, to be assembled according to customers’ preferences. Color-coded universal and size-specific instrument and implant trays support the surgeon and the tech staff in choosing the right instruments for the selected plates.
Fig 3: Overview of the VOLT Small Fragment generic plates. 
Fig 4: Overview of the VOLT Mini Fragment screws. 
Fig 5: Overview of the VOLT Small Fragment screws. VOLT locking technology
A key innovation of the VOLT platform is the novel variable angle locking technology (Figs 5–6). The VOLT holes appear round but actually have a subtle triangular shape with threads that are precisely engineered with tight manufacturing tolerances. The unique shape of the VOLT holes enables the plate threads to adapt to the screw threads as the screw is inserted. The result is excellent plate to screw engagement and robust cantilever strength. The technology allows for a screw angulation of up to 15°, hence a locking cone of 30°.
Fig 6: Shown here on a 3.5 metaphyseal plate are examples of all VOLT hole types: VOLT hole, VOLT combi hole, and VOLT elongated combi hole. The combi and elongated combi hole incorporate the DCU, known from the LCP and Limited Contact Dynamic Compression Plate (LC-DCP) systems, as well as the variable angle locking screw hole. 
Fig 7: VOLT variable angle locking is designed to enhance engagement between the screw and the plate for maximum interface locking strength. The combi holes feature the new locking technology in the locking part of the combi hole as well as the proven DCU functionality in the non-locking part of the hole. The cantilever strength of a VOLT plate/screw (2.4 mm, 2.7 mm, 3.5 mm) interface at nominal (0°) is equivalent to the LCP plate/screw interface at nominal (0°), yet VOLT delivers variable angle capability (Static Cantilever Strength; Fig 7). Thus, the VOLT technology combines the advantages of an LCP with the option of variable angle locking technology. Also, the new combi holes benefit from the VOLT locking technology in the locking part of the combi hole.
All VOLT hole types accept the use of either locking or cortex and cancellous screws. Accordingly, the same fixation principles apply as with previous LCP and VA-LCP systems, facilitating education and transition to VOLT.
Fig 8: Static cantilever strength of 3.5 mm locking interfaces at 0° screw insertion. Values above 4Nm indicate that something other than the plate/screw interface failed. This means that the plate/screw interface is stronger than the implants. Screws
A combination of locking, cortex, and cancellous screws offers versatile options tailored to the VOLT plates. To streamline the surgical steps, instruments are color-coded according to screw diameter. Additionally, a single- or double-band etching assists in identifying complementary parts.
Screws, equipped with an optimized Stardrive recess design (Fig 8), along with new screwdrivers, are intended to enhance the user experience. In addition to the optimized recess design, cortical and cancellous screws have lower profile heads compared to previous designs due to soft-tissue considerations.
The locking screws are designed for locking performance, while offering cutting flutes for ease of insertion and a rounded screw tip (Fig 8), both designed to reduce the risk of soft-tissue irritation.
In the VOLT Small Fragment system, the 4.0 mm cancellous screw offers better hold in the bone compared to the 3.5 mm cortical screw and remains an important fixation option in epi-metaphyseal zones. To support removal, the cancellous shaft screw features back-cutting flutes.
The system offers longer screws compared to its predecessor, providing greater versatility (2.0 mm: up to 50 mm; 2.4 mm and 2.7 mm: up to 90 mm; 3.5 mm: up to 110 mm).
Fig 9: Screw features that aim to provide excellent handling and fixation. Plates
The VOLT Mini and Small Fragment Plating Systems feature a wide range of generic plates (Fig 1) . Generic plates, also called non-anatomic or utility plates, are a key pillar in trauma surgery due to their adaptability and versatile application as primary fixation or as an auxiliary fixation device to other implants. All new generic plates feature VOLT technology (Fig 9).
Several new plate shapes and lengths have been introduced. Design features on the plates such as rounded profiles and tapered tips are beneficial as they respect soft tissue and can be used in less invasive surgical techniques. VOLT plate shapes and screw hole patterns are intended to optimize plate function, whether for locking, compression, or buttressing, ensuring efficacy and stability in various orthopedic applications. Furthermore, plate options with increased screw hole density are available, offering more fixation options and thereby providing surgeons with greater flexibility and precision to meet daily fracture fixation challenges.
VOLT titanium plates and screws are anodized and then treated with an electropolish finish. Electropolishing the titanium plates and screws produces a surface texture (Fig 10) similar to stainless steel. This smooth surface finish reduces bony ongrowth and soft-tissue adhesion, which has been shown to ease implant removal.
Fig 10: (a) standard 8-hole VOLT 2.7 mm plate with combi holes and (b) compact 8-hole VOLT 2.7 mm plate. (c) electropolished VOLT titanium implant. (d) Electropolishing generates a surface smoothness similar to stainless steel. Plate types and features
Straight plates
Straight plates are available for all sizes and are optimized for strength. The proven plate undercuts from LC-DCP and LCP are maintained to give the plate a widely uniform stiffness, supporting continuous bending while limiting contact with the bone when applied with non-locking screws. While keeping the rounded, smooth tip to support less invasive insertion, holes are also placed close to the ends of the plate, offering a wide fixation range (Fig 11). Two K-wire holes give an additional option for temporary fixation. The 2.0 mm, 2.4 mm, and 2.7 mm plates are also available in a compact version.
Fig 11 (a) straight plate with K-wire holes and tapered tips to support insertion. (b) the holes at either end of the plate are very close to the tip. Mini Fragment generic plates
- Adaption plates
Adaption plates offer the surgeon greater freedom to adapt the plate to specific anatomical situations. Accordingly, they are optimized to allow in-plane, out-of-plane, and torsional bending and cutting to trim the plate to the length needed. Additional focus was given to producing a low and smooth plate profile as these plates are often used in soft-tissue critical zones. Depending on the adaption plate type, the plates offer the VOLT hole, combi hole, elongated combi hole. or a combination thereof (Fig 12). Adaption plates were developed for sizes 2.0 mm, 2.4 mm, and 2.7 mm.
- Straight adaption plates
These plates are available with a combi hole and in a compact version (Fig 13). The plates are offered in a length of up to 20 holes.
Fig 12: (a) Adaption plate profile with various hole options. (b) 12-hole adaption plate with combi hole and (c) 12-hole adaption plate compact version. - Condylar, Y, and T plates
These plates feature a head element (Fig 14) and are suited for fracture situations where additional fixation options are required.
- Hook plates
The hook plate’s adaptability and sharp hooks (Fig 15) allow the plate to grab and hold small fracture fragments close to a joint and compress them to the shaft. A recess between the hooks (Fig 16) supports the secure placement of a cortical screw if needed.
- Triangle plates
The triangle plate (Fig 17) is designed to offer a broader buttressing surface with multiple fixation options. Therefore, the plate has a triangular head shape.
- Tine plates
The tine plate (Fig 18) was developed to give a broader buttress surface and to offer additional support to hold small fragments. Therefore, the plate features a two-hole wide head and two tines that grab the bone.
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