Basic Orthopedic Hardware

Internal Fixation Hardware

1. Screws 2. Plates

3. Pins and Wires

4. Intramedullary rods and nails

5. Anchors

Screws Overview

Screws are the most common general purpose fixation devices. They may be the only hardware used in reparative or reconstruction surgery. More commonly, however, they are used with other hardware devices, particularly plates, to fixate the associated device to bone. For fractures that have large well-defined components, screws are used both to fixate plates and as standalone devices to fixate the fracture fragments.

The main features of a screw are shown to the right along with the standard names for its parts. Each of the parts can be modified to produce screws with specific characteristics. The most common variations are differences in spacing between the threads (pitch), core diameter, and tip design. Screws can have hollow (cannulated) or solid central axes and can be fully or partially threaded. Screws tips are designed to be tapping or nontapping (see glossary). Screws are often referred to by the outer diameter of

the threaded portion, 3.5, 4.5, and 6.5 mm screws being the most common.

Upper Extremity Buttress Plates

 

 

 

 

Medial Distal Humeral  Plate

Lateral Distal Humeral  Plate

Greater Tuberosity Humeral  Plate

Posterior Ulna/Olecranon Plate

Tibial Buttress Plates

 

    

 Proximal Medial Tibial Plate

 Proximal Lateral Tibial Plate

 Distal Medial Tibial  Plate

 Distal Lateral Tibial Plate

Lateral Tibial Buttress Plate

 

Lateral tibial buttress plate: AP and lateral views. Note the L-shape which is only apparent in the lateral view. Two cancellous screws inserted through the tibial plateau act as lag screws. Four cortical screws transfix the vertical portion of the plate to the tibial diaphysis.

Calcaneal Buttress Plate

 

Calcaneal Buttress  Plate: The plate is similar in appearance to a reconstruction plate. There are several different designs which can be tailored to the fracture pattern of the calcaneus.

 

Calcaneal Buttress Plate

Kirschner (K) Wires

  

Kirschner wires have many uses. They can be used as the primary fixation device for fractures in the hands and feet. They can also be used as adjunctive fixation devices for complex fractures of larger bones. The x-ray on the right shows a bimalleolar fracture. The medial malleolus is fixated with a plate with screws and by two K-wires. There is a Rush rod in the fibula.

Cables

Cables are used primarily as adjunctive fixation devices for fractures of the long bones. Their use is illustrated in the x-ray at the right. The cables around the proximal femur provide compression to the bone and help improve contact with the femoral prosthesis. This prosthesis is a noncemented, bone ingrowth type and the compression improves bone ingrowth.

Tension Band Wiring

Tension band wiring of a patellar fracture, lateral and AP views of the knee. The tension band wire has a characteristic figure of eight appearance and has been reinforced with K-wires. Note on the lateral view that the wires are placed anteriorly. 

FEMORAL NAIL

Illustration of how a femoral nail is inserted and how the locking pins are placed. In this example, the nail has been placed in a retrograde fashion. Typical femoral nail with one proximal and two distal transverse locking pins. Used primarily for diaphyseal fractures.

PROXIMAL FEMORAL NAIL

Intertrochanteric fracture fixated with a proximal femoral intramedullary nail. This nail is designed for proximal femoral fractures, especially in the intertrochanteric region.  Nails for proximal fractures must be thicker to withstand the high stress  in the intertrochanteric and subtrochanteric regions.

LONG PROXIMAL FEMORAL NAIL

Femoral neck and diaphyseal fractures fixated with a long  femoral intramedullary nail and proximal locking lag screw. This nail is designed for combined fractures of the proximal femur and the  diaphysis.  Nails for proximal fractures must be thicker to withstand the high stress in the intertrochanteric and subtrochanteric regions.

TIBIAL INTRAMEDULLARY NAIL

Pre-op image of proximal diaphyseal fractures of the tibia and fibula. Intramedullary tibial nail inserted in a static configuration with proximal and distal locking screws Typical tibial nails with proximal and distal transverse holes for locking pins.

Antibiotic Rods

  

  

Treatment of infections of intramedullary rods is difficult. The rod must be removed, but standard intravenous antibiotic treatment cannot deliver high concentrations of antibiotics to the affected bone. One method of accomplishing such delivery is with an antibiotic rod as shown on the right. The infected tibial rod was removed. A chest tube was used to contain a slurry of antibiotics and a biocompatible material such as polymethylmethacrylate that quickly hardens. The material is placed in a chest tube with a thin diameter wire. When the material hardens sufficiency, it is extracted and inserted into the tibial medullary space.The antibiotic leaches from the rod achieving higher concentrations than could be obtained with intravenous administration.