The LCP can be used as conventional plate with conventional screws. It may then have one of five functions: ie, compression, bridging, buttress, protection, and tension band. With the use of an eccentric drill guide, axial compression can be obtained or a lag screw can be placed through any plate hole. This classical fixation is still applicable for articular fractures and in simple type A and B1 fractures in the meta-/diaphyseal area, where anatomical reduction and absolute stability is recommended and can easily be achieved without wide exposure. Other indications are closed wedge osteotomies as well as delayed and nonunions, where absolute stability is recommended. The LCP can also be used as a plate to protect a lag screw fixation. If only locking head screws are used then this could be considered to be a “protecting internal fixator”.

Compression with a LCP providing absolute stability for complex articular fracture: 20-year-old male with a displaced distal intraarticular humerus fracture (13-C3) after a fall on the right elbow while cycling.

Initial AP and lateral x-rays.

AP and lateral x-rays

AP and lateral x-rays after open reduction and internal fixation (ORIF) with two LCP reconstruction plates 3.5. Note the interfragmentary lag screw through the ulnar side plate and the (eccentrically drilled hole for the) cortex screw on the radial side plate for axial compression. Olecranon osteotomy was used for better access to the joint.

10-month follow-up with anatomical joint congruity and return to full function after primary bone healing.

10-month follow-up with anatomical joint congruity and return to full function after primary bone healing.

LCP used as “protecting internal fixator”.

a Simple oblique radius shaft fracture (22-A2).

b ORIF with plate-independent lag screw. To protect it and to obtain absolute stability the LCP 3.5 is applied as internal fixator with four monocortical locking head screws.

c 5-month follow-up showing direct fracture healing.

Fixation of a short oblique fracture with a lag screw. LCP used as a “protecting internal fixator”.

The LCP can be used with both conventional and locking head screws inserted in the same fracture segment, but the order of screw insertion is critical.

• Once a locking head screw has been inserted in one segment of a fracture, no further conventional screws should be added to this segment, as this will introduce unwanted forces. “Lag first, lock second”.

In articular fractures (requiring an anatomical reduction and fixation by interfragmentary compression) lag screws may be essential for the reconstruction of the articular components. At the same time, a locking head screw can provide angular stability, to prevent secondary displacement.

The use of both types of screws (conventional and locking head) can be considered in the following situations [12, 13]:

• fracture reduction onto a plate in case of residual axial malalignment of a fracture
• providing interfragmentary compression by a lag screw for an intraarticular fracture combined with angular stability with a LHS, eg, tibial plateau fracture;
• segmental fracture with two different fracture types (one simple, the other complex), which require different kinds of stability (one absolute, the other relative stability);
• malalignment of the plate with respect to the long bone axis. When the plate is not ideally aligned to the axis of the diaphyseal segment, the screw at the plate end may not
  meet the bone cortex when a locked screw (with its predefined screw direction) is used.

A conventional, cortical screw is used to correct malalignment and reduce the fracture onto the plate. This is particularly helpful in the tibia where displacement can cause tenting of the skin by the plate, and pressure necrosis. Final fixation is completed with locking head screws to provide angular stability.

• A conventional, cortical screw is used to correct malalignment and reduce the fracture onto the plate. This is particularly helpful in the tibia where displacement can cause tenting of the skin by the plate, and pressure necrosis. Final fixation is completed with locking head screws to provide angular stability.

Initial AP and lateral x-rays.

LCP used with conventional and locking head screws to provide absolute stability for the articular fracture and relative stability for the complex meta-/diaphyseal fracture: 46-year old male with a displaced pilon fracture.

CT scan after spanning external fi xation (demonstrating central impaction).

7 days later, ORIF for the fibula (one-third tubular plate 3.5), limited ORIF for articular reconstruction, and minimally invasive plating of the meta-/diaphyseal fracture. Two lag screws (conventional cortex screws) are placed distally through the LCP providing compression and absolute stability of the articular block. At the metaphysis, a conventional screw (“reduction screw”, arrow) is placed through the plate for approximation of the grossly displaced fragment.

1-year follow-up demonstrating primary bone healing (without callus) of the articular segment and secondary bone healing (with callus) of the meta-/diaphyseal part. The patient demonstrates no osteoarthritis and full return of function.

Choosing to use the LCP depends on bone quality, fracture pattern, anatomical region and the surgeon’s preference. It is the surgeon who determines the type of stability/fixation, and thus the mode of healing, and not the plate per se. By making the correct decision in using the LCP in specific cases, the surgeon can significantly contribute to the improvement in the clinical outcome after fracture [14].

However, there are also hazards if the principles are not correctly applied.

Some rules, shortcomings, and disadvantages of bridging the fracture zone with locked internal fixators include:

• Careful preoperative planning, including the order of screw insertion, is highly recommended.
  • When inserting the first locking head screw with the power drive it is important to firmly secure the LCP. As the locking head engages the plate, high torque can cause the plate to spin and result in soft-tissue damage.
• Precise placement of locking head screws and the use of a torque limiting screw driver are mandatory to achieve an angular-stable connection. This predetermines the screw direction and facilitates screw removal.
• When inserting the first locking head screw in a fracture fragment with hard cortical bone, the threads of the screw may fail to engage the far cortex. The head then engages the plate and moves the plate away from the bone, potentially causing a loss of reduction.
• In periarticular fractures, care must be taken to avoid penetration into the joint by angular-stable screws.
• The stability of the fracture fixation depends on the stiffness of the construct. The plate and screws are exposed to higher loads.
• Closed reduction and intraoperative imaging of alignment can be demanding, potentially leading to a higher percentage of malalignment or malunion.
• Minimally invasive plate application and fixation is technically demanding and requires practice.
• Excess traction on the skin, to achieve a smaller incision, should be avoided.

The LCP can be used as a pure locked internal fixator based on the principle of relative stability by bridging the fracture zone. Here, locking head screws are used exclusively. After indirect reduction, the complex type C fracture zone is not exposed but bridged by a long, locked plate. Preserving vascularity in combination with internal splinting allows rapid fracture healing with external callus formation. The fractured bone should be appropriately aligned before the LCP  is applied. While temporarily, inserted conventional cortex screws may be used as a reduction aid or to approximate a large fragment, little or no contouring of the plate is needed.

Initial AP (a) and lateral (b) x-rays.

48-year-old male who sustained a closed fracture: distal tibia shaft (42-B3) in combination with a lateral malleolar fracture with Volkmann triangle (44-C2). Example of the LCP used in two mechanical modes in the same patient. The fibula is fixed with lag screws and the LCP acts as a protection plate to provide absolute stability. The multifragmentary tibia is fixed using MIPO with a bridge technique providing relative stability.

Fibula with one large spiral wedge allowing open, direct anatomical reduction as the first step (c). The tibia has at least two intermediate fragments. Therefore, a minimal invasive plate osteosynthesis (MIPO) with a LCP 4.5 bridging the fracture zone is a safe alternative, provided that correct alignment and rotation is achieved by indirect reduction (d).

X-rays after 6 weeks.

After 14 months. The tibia has healed with callus formation and the remodeling process has been completed. There has been primary healing of the fibula without callus formation.

The LCP used as an internal fi xator to bridge a multifragmentary fracture.

Final fixation is secured with locking head screws. The plate is not pressed against the bone, nor are the fragments pulled towards the plate. This facilitates percutaneous plate insertion and the use of monocortical as well as bicortical screws. Furthermore, in osteoporotic bone the angular stability provided by every LHS appears to be very effective because of the higher resistance to pull-out than with conventional cortex screws.

In osteoporotic bone, locking head screws are less likely to fail than conventional screws.

Other indications for the use of the LCP as a pure internal fixator include the stabilization of periprosthetic fractures, secondary fractures or rotational instability after intramedullary nailing as well as applications in tumor surgery. When using the LCP, careful preoperative planning is essential. The surgeon must understand the differences of the two principles of fracture fixation: absolute and relative stability. He/she should also take into consideration that the biomechanical environment created by the plate will greatly influence the mode of fracture healing. It is important to understand both methods—compression and splinting—their different techniques, and their different applications.

The benefits of the internal fixator principle are enhanced by the combination hole concept because

• angular stability is provided by locking head screws (even if monocortical);
• accurate plate contouring is not required;
• there is less damage to the periosteum and its blood supply;
• there are more options and greater versatility in fracture management, especially of complex articular and metaphyseal fractures;
• there is better fixation in osteoporotic bone.

[1] Schatzker J (1995) Changes in the AO/ASIF principles and methods. Injury; 26(Suppl 2):51–56.

[2] Ganz R, Mast J, Weber BG, et al (1991) Clinical aspects of biological plating. Injury; 22(Suppl 1):4–5.

[3] Mast J (1991) Preoperative planning and principles of reduction. Müller ME, Allgöwer M, Schneider R, et al (eds), Manual of Internal Fixation. Berlin Heidelberg New York: Springer-Verlag, 159–178.

[4] Perren SM (1991) Basic aspects of internal fixation. Müller ME, Allgöwer M, Schneider R, et al (eds), Manual of Internal Fixation. Berlin Heidelberg New York: Springer-Verlag, 1–112.

[5] Perren SM, Buchanan JS (1995) Basic concepts relevant to the design and development of the Point Contact Fixator (PC-Fix). Injury; 26(Suppl 2):1–4.

[6] Tepic S, Perren SM (1995) The biomechanics of the PC-Fix internal fixator. Injury; 26(Suppl 2):5–10.

[7] Perren SM (2002) Evolution of the internal fixation of long bone fractures. The scientific basis of biological internal fixation: choosing new balance between stability and biology. J Bone Joint Surg Br; 84 (8):105–113.

[8] Krettek C (1997) Concepts of minimally invasive plate osteosynthesis. Injury; 28(Suppl 1):1–2.

[9] Krettek C, Schandelmaier P, Miclau T, et al (1997) Minimally invasive percutaneous plate osteosynthesis (MIPPO) using the DCS in proximal and distal femoral fractures. Injury; 28(Suppl 1):A20–30.

[10] Wagner M, Frigg R (2006) Internal Fixators—Concepts and Cases Using LCP and LISS; Stuttgart New York: Georg Thieme Verlag.

[11] Wagner M (2003) General principles for the clinical use of the LCP. Injury; 34(Suppl 2):31–42.

[12] Schütz M, Südkamp NP (2003), Revolution in plate osteosynthesis: new internal fixator systems. J Orthop Sci; 8(2):252–258.

[13] Gautier E, Sommer C (2003) Guidelines for the clinical application of the LCP. Injury; 34(Suppl 2):B63–76.

[14] Sommer C, Gautier E, Müller M, et al (2003) First clinical results of the Locking Compression Plate (LCP). Injury; 34(Suppl 2):B43–54.