Cannulated Screw Short Thread 4.5mm

Description

REF. NO. LENGTH 682.20   20 mm 682.22   22 mm 682.24   24 mm 682.26   26 mm 682.28   28 mm 682.30   30 mm 682.32   32 mm 682.34   34 mm 682.36   36 mm 682.38   38 mm 682.40   40 mm 682.42   42 mm 682.44   44 mm 682.46   46 mm

REF. NO. LENGTH 682.48   48 mm 682.50   50 mm 682.52   52 mm 682.54   54 mm 682.56   56 mm 682.58   58 mm 682.60   60 mm 682.62   62 mm 682.64   64 mm 682.66   66 mm 682.68   68 mm 682.70   70 mm 682.72   72 mm 682.74   74 mm

Technical Specification Thread Diameter                            4.5 mm Drill Bit for Threaded Hole            3.2 mm Shaft Diameter                               3.1 mm Core Diameter                                2.7 mm Hexagonal Socket                           3.5 mm Head Diameter                             6.5 mm Cannulation                                    1.75 mm Guide Wire                                     1.6 mm

4.5 mm Locking Cannulated Screw Specification

• 4.5 mm Locking Cannulated Screw available lengths are 20mm, 22mm, 24mm, 26mm, 28mm, 30mm, 32mm, 34mm, 36mm, 38mm, 40mm, 42mm, 44mm, 46mm, 48mm, 50mm, 52mm, 54mm, 56mm, 58mm, 60mm, 62mm, 64mm, 66mm, 68mm, 70mm, 72mm & 74mm.
• 4.5 mm Locking Cannulated Screw has Cancellous thread. Cancellous thread profile uses deep cutting threads with a large pitch to increase resistance to pullout. Large pitch also accelerates screw insertion and removal.
• 4.5 mm Locking Cannulated Screw is made from pure Titanium and SS 316L.
• Any additional length sizes of this screw will be made on demand.
• This is Self Tapping Screw. Self Tapping Screws cuts its own thread while being driven into the bone. It makes a small hole while entering the bone which creates a tight friction fit between the threads. This helps fight vibration loosening and allows the parts to be taken apart if needed..
• Instruments are available for this screw such as Bone Taps, Combined Drill & Tap Sleeve, Counter Sink, Depth Gauge, Drill Bits, Drill Guide, Drill Sleeve, Hollow Mill Screw Removal, Reverse Measuring Device, Screw Drivers and Screw Holding Forceps etc.

4.5 mm Locking Cannulated Screw uses

4.5 mm Locking Cannulated Screw is intended for fixation of fractures, fusions, and osteotomies of Small and large bones appropriate for the size of the device.

Cannulated screw have a hollow central shaft. Both cortical and cancellous screws can be cannulated. Cannulated cancellous screws are used for metaphyseal fractures while cannulated and non-cannulated cortical screws are used as lag screws for fixation of diaphyseal fractures.

Partially threaded screws may be used to lag one bone fragment to another, where the bone fragment is captured by the threads of the screw and pulled toward the near cortex fragment on the head side of the screw. Fully threaded screws are intended to be used to stabilize fractures with little to no compression across the fracture.

Cannulated screw system provide emergency closed reduction, percutaneous screw fixation and excellent stability.

Cannulated bone screws in comparation with traditional screws decrease surgical time, allow more precise screw placement and reduce possibility of errors.

One special type of cannulated cancellous screw is the Knowles pin which is a Cannulated screws used for fixation of slipped capital femoral epiphysis in children.

Bone screws are the most commonly used orthopedic implants. There are many different types and sizes of screws for different types of bones. Most bone screws are made out of stainless steel or titanium alloys. The outer diameter, root diameter, and thread pitch and angle are important in determining screw mechanics.

In orthopedics, screws are typically described by their outer diameter, for example, a “4.5 mm Locking Cannulated Screw” has an outside diameter of 4.5 mm. The pitch of a screw is the linear distance travelled by a screw for one full turn of the screw. The screw advances by a distance equal to the distance between the threads with each full turn. Cortical screws have a lower pitch and therefore more number of threads. Cancellous bone screws have a greater depth of the screw to increase the surface area and therefore improve the purchase, as the bone is weaker.

Screws function by converting the tightening torque into internal tension in the screw and elastic reactions in the surrounding bone. This creates compression between the fracture fragments that the screw is holding together. 4.5 mm Locking Cannulated Screw is typically inserted into holes drilled equal to the root diameter and are either self-tapping or are inserted tapped (threaded) holes. The torque to insert cortical bone screws can be high, so the screws must be properly inserted into the correct size drilled hole and designed to with stand insertion torque levels expected in cortical bone. Cancellous bone screws have large, deep threads that grip the spongy bone well. Because of the relatively low strength of the cancellous bone, failure of the screw itself during insertion is rare, but pull out can be an issue.