Chapter 3: Table of contents
Other Instruments (in alphabetical order):
AMEROID CONSTRICTOR:
An ameroid constrictor is a device used to slowly and gradually occlude a shunt (often used for extrahepatic portosystemic shunts). By gradually occluding the shunting vessel, the ameroid constrictor allows for vascular compensation preventing sudden portal hypertension. They are constructed of a stainless steel ring and a casein insert and key (the key is the small cylindrical piece). The ring is gently placed around the vessel and the key is inserted to ensure the ring remains around the vessel. Casein swells within the steel ring as it absorbs body fluid, constricting the vessel over time.
BONE CUTTING FORCEPS:
Bone cutting forceps are single or double-action instruments that have two sharp, chisel-like blades that enable the surgeon to sharply cut bone.
- Stille-Liston Double Action:
Stille-Liston double action, bone cutting forceps are large and bulky which can limit their use in smaller patients or in confined spaces. Their double-action mechanism provides a mechanical advantage by decreasing the force required to cut bone.
- Liston Bone-Cutting Forceps:
These single-action bone-cutting forceps resemble the Stille-Liston bone cutting forceps.
- Ruskin Bone-Cutting Forceps:
These double action bone-cutting forceps are smaller and more delicate than the Stille-Liston and Liston bone cutting forceps.
BONE HOLDING FORCEPS:
Bone holding forceps are used to maintain bone alignment during fracture repair or to obtain a firm grasp of a bony structure during surgery. Bone holding forceps can also be used to appose and maintain the exact position of a bone plate along a fractured bone during repair. Bone holding forceps are generally self retaining and easy to use.
- Kern and Lane:
Kern and Lane bone holding forceps have two jaws each equipped with two sharp prongs at the distal tip to ensure a good grasp of the bone. These instruments are available with or without a ratchet and in various sizes. Care must be taken not to tightened the ratchet excessively to prevent bony fissure or fragmentation.
- Speedlock:
These reduction forceps are equipped with a clam-shell jaw and a speedlock mechanism allowing the surgeon to rapidly reduce and maintain bone fragments while fracture repair is accomplished.
- Sharp Bone Reduction:
Sharp Bone Reduction Forceps description: Sharp bone reduction forceps are equipped with pointed tips and a ratchet mechanism allowing the surgeon to rapidly reduce and maintain bone fragments while fracture repair is accomplished.
- Lowman:
This clamp is not useful to manipulate bones but can be used to hold a reduced long bone fracture and a bone plate during fracture repair.
BONE RASP:
A bone rasp is often used to remove bony irregularities during orthopedic surgery. For example, a rasp can be used to smooth the cut edge of the proximal femur after femoral head and neck osteotomy.
BONE SCREWS AND PLATES:
Metal implants such as bone plates and screws are frequently used to maintain reduction of fractured bones during the healing period. In addition to providing a stable fixation, they can provide compression (DCP), or bridging/buttress at a fracture site. These implants come in various sizes, configurations and are made with various materials (e.g. titanium and 316-L stainless steel). Bone plates (and screws) are typically not removed after the bone has healed unless they are associated with significant problems such as infection, irritation, breakage or loosening, cold conduction, etc.
CURRETTES:
- Neurological Currettes:
These miniature currettes are designed to remove small disc fragments from the spinal canal or from a disc space. Because of their small size, care must be taken not to place too much pressure on the currette to prevent breakage. For this reason, these currettes are not recommended to remove bony fragments at the edge of a laminectomy.
- Spratt Bone Currettes:
This curette has a round or oval cup on the end of a strong steel shaft. The sharp edges of the cup enable to collect bone grafts and debride soft or bony tissues.
- Volkman Bone Currettes:
Volkman bone curettes are double-ended with an oval or rounded cup at either end. These serve the same purpose as Spratt bone currettes.
DRILLS:
- A/O:
The A/O drill is a hand-held, air driven drill used to drill holes or insert metal implants such as pins into bones during orthopedic procedures.
- Hall:
The Hall air drill is a hand-held, air driven drill that is used to burr through bone especially during neurosurgical procedures such as laminectomies.
GIGLI WIRE:
Gigli wire is a grooved, single stranded wire used to cut through bone. Unlike bone cutting forceps, it does not crush bone as it cuts. The T-shaped handles provide a secure grasp of the wire, allowing the surgeon to saw with a back and forth motion. Caution should be taken to prevent damage to the surrounding soft tissue from the heat produced by friction.
- Gigli Wire vs. Embryotomy Wire: Gigli wire (top) is a grooved, single stranded wire used to cut through bone. Embryotomy wire is made of several strands of fine wire that are braided and twisted (bottom).
HOBBY SAW:
Hobby saws (also known as X-Acto saw) are typically purchased in hardware stores and are fairly inexpensive. They can be sterilized in an autoclave and are used to perform precise cartilage and sub-chondral bone cuts in orthopedic surgery (e.g. trochleoplasty to treat patellar luxation).
JACOB’S CHUCK AND KEY:
A Jacob’s chuck is often used to manually insert pins or Kirshner wires into bones. An alternative to this instrument is to use an air driven drill.
KIRSHNER WIRE AND PINS:
Stainless steel pins and wires of various sizes are used to appose bony fragments in orthopedic surgery. These can be driven through the bone by hand (e.g. using a Jacob’s chuck) or with air-powered instruments.
MALLET:
A mallet is a surgical hammer that is used to strike the striking surface of an osteotome in order to cut bone. The metal striking surface of the mallet is sometimes covered with a synthetic material.
MICHELLE TREPHINE
This T-shaped instrument is used to obtain a relatively large, cylindrical bone biopsy sample (usually includes cortex and medullary bone) thus creating a relatively large cortical defect. The instrument is graduated along it’s shaft to indicate penetration depth and is available in different sizes. The blunt stylet is removed during sample collection and used to retrieve the sample from the instrument core.
OSTEOTOMES:
Osteotomes are double beveled instruments (compared to chisels which are single-beveled)used to shape or cut bones in orthopedic surgery. A mallet is used to strike the striking surface of the osteotome. Various types and sizes of osteotomes are available.
On the left, a Hoke osteotome (with a circular striking surface) is demonstrated. The Hibbs osteotome (not seen here) is very similar to the Hoke osteotome only it is larger. The Army pattern osteotome (middle) has a prominent circular striking surface. The Lambotte osteotome (seen on the right) is flat and is characterized by a rectangular striking surface.
PERIOSTEAL ELEVATORS:
Periosteal elevators are used to elevate muscles from bones during orthopedic and neurosurgical procedures. Several types of periosteal elevators are available with a variety of tip shapes and widths. Some are single ended and others such as the Freer elevator are double ended.
- Wooden Handle:
Some periosteal elevators are single ended with wooden handles shaped to improve handling.
- Freer:
Some periosteal elevators are single ended and others such as the Freer elevator are double ended.
PIN BOX:
The pin box holds a collection of Kirschner wires (K-wires) and Steinmann pins used for intrafragmentary or intramedullary bone pinning. The Kirschner wires are smaller in diameter and can be used for a variety of orthopedic techniques (tension bands etc.). The Steinmann pins are larger in diameter and are often used for intramedullary pinning.
PIN CUTTERS:
Pin or wire cutters are forceps-like instruments used to cut metal implants during orthopedic surgery. These instruments are available in various sizes and shapes.
RETRACTORS:
Retractors greatly increase the visibility of structures in a surgical site. Several kinds of retractors have been developed for various purposes. The two major categories of retractors are hand-held retractors and self-retaining retractors.
Hand Held Retractors:
Hand held retractors require that an assistant retract tissues by holding the retractor in the desired direction.
- Mathew-Senn:
Senn retractors have three curved, sharp prongs at one end (The Mathew retractor is similar but has three blunt prongs at one end) and a right angle blade at the other end of the instrument. These are used to retract skin and superficial muscles.
- Hohmann:
Hohmann retractors have a large blade with a central extension known as a ‘beak’. This instrument allows exposure of the shaft of a bone while the blade is pushing away surrounding muscle. Hohmann retractors are available in various lengths and blade widths. A mini-Hohmann retractor is also available.
- Army Navy:
Army-navy retractors are relatively flat instruments with 90-degree blades at either end. The blades on the retractor come in varying sizes, depending on the depth required. This instrument is commonly used to retract large muscle groups during neurological and orthopedic procedures.
- Rake:
These retractors are wider than Mathew or Senn retractors and are available with blunt or sharp tips. These are typically used to retract skin and muscle.
- Maleable:
Maleable retractors can be bent repeatedly and conformed as needed to fit various angles or depths. They are useful during abdominal and thoracic surgery but tend to look rather unaesthetic after repeated use. The instrument is available in various lengths and blade widths.
- Finger:
Finger retractors are shaped similarly to Army-navy retractors with 90-degree blades at either end but are significantly smaller requiring that they be held with fingers rather than the palm. This instrument is used for gentle retraction of small structures.
- Desmarres:
Desmarres retractors are typically used to gently retract soft tissue structures such as the eyelids and blood vessel walls during ophtalmic and cardiovascular surgery.
Self Retaining Retractors:
Self retaining retractors are characterized by a mechanism (ratchet or bolt) that locks them into place allowing the surgeon to have both hands free for the procedure.
- Gelpi:
Gelpi retractors are available in varying sizes. Their curved arms and sharp angled tips provide good leverage on tissues being retracted. A ratchet mechanism allows this instrument to remain in the spread position after retraction. They were developed for perineal retraction but are frequently used for deep muscle retraction during neurologic or orthopaedic surgery.
- Weitlaner:
Weitlaner retractors are available in varying sizes. Just like Gelpi retractors, Weilaner retractors have curved arms but instead of having a sharp pointed tip they have varying numbers of curved (sharp or blunt) prongs on either end. A ratchet mechanism allows this instrument to remain in the spread position (with various degree of spread) after engaging the ratchet. These retractors are often used for soft tissue, orthopedic or neurologic procedures.
- Inge Lamina Spreader:
Lamina spreaders are equipped with a ratchet mechanism at the tip of the handles that allows to maintain hands-free retraction. These retractors are designed to accomplish temporary distraction of vertebrae and can be used in neurosurgical procedures such as distraction/stabilization of Wobbler lesions in dogs. Another common use in veterinary surgery is during stifle exploration in order to distract the tibia from the femur allowing the menisci to be visualized. When used in this fashion, great care must be taken not to damage the articular cartilage.
- Balfour:
The Balfour retractor is an indispensable instrument used to retract the abdominal wall during abdominal procedures. The instrument is available in various sizes providing variable spread and with solid or fenestrated side blades. Balfour retractors also typically have a central blade. The retaining mechanism of the Balfour retractor is less secure than the ratchet mechanism as it relies on the blades binding against the head bar when retraction is applied. Some instruments also have a tightening bolt mechanism to allow further security.
- Gosset:
The Gosset retractor functions similarly to the Balfour retractor, but it is generally smaller and does not have a central blade.
- Finochietto:
The Finochietto retractor is a rib spreader and is thus used for thoracic surgery requiring a sturdy self-retaining retractor. These retractors are available in 6 to 12 inch spread on either curved or straight arms. Blade depth is also variable. The spread is obtained by turning a handle until adequate exposure is obtained. This instruments is secure and very sturdy.
RONGEURS:
Rongeurs are forceps-like instruments equipped with sharp-edged, cupped jaws. These instruments are used to remove small or large sections of bone during orthopedic and neurosurgical procedures. Rongeurs of various sizes and jaw configurations are available; smaller, more specialized rongeurs are used for delicate procedures (e.g. Kerrison rongeur is often used for spinal surgery). Double action instruments provide a mechanical advantage over single action instruments by lessening the force required to cut bone.
- Duck Bill:
This rongeur can be designed as a single or double action instrument and is characterized by the shape of its jaw.
- Lempert:
These rongeurs are single-action with tapered jaws and are typically used for delicate and fine procedures such as neurosurgery
- Kerrison:
This very specific rongeur is composed of one long blade that ends as a footplate at the tip of the instrument while the other blade has a cutting end that meets the footplate when the instrument is closed. Kerrison rongeurs are frequently used in neurosurgical procedures by gently sliding the footplate between the spinal cord and the bony lamina to remove small bony fragments exposing the spinal cord further. This instrument is especially useful in the cervical and lumbosacral areas because of the relatively greater space between the spinal cord/nerve roots and the bone. The cutting action of this instrument can be up- or down-cutting.
- Double Action Ruskin:
This is a rongeur with tapered jaws used to grip smaller bites of bone. The double action configuration provides a mechanical advantage over a single action instrument by lessening the force required to cut bone.
- Stille-Luer:
This is a large double-action rongeur with blunted jaws. The double action configuration provides a mechanical advantage over a single action instrument by lessening the force required to cut bone.
RUMEL TOURNIQUET:
A Rumel tourniquet is used to temporarily occlude large vessels, often during a venotomy or arteriotomy. They are often constructed from sterile tubing and umbilical tape. Hooked, stainless steel wire is used to thread the tape through the tubing.
SPAY HOOK:
Spay hooks are long, thin instruments with a blunt hook at one end that can be used to retrieve a uterine horn during an ovariohysterectomy. This allows the surgeon to perform the procedure through a relatively small incision. There are two main types of hooks, the Snook (pictured here) and Covault hooks, which differ only slightly in their tips and handles.
SPINAL KITS:
Spinal kits are specialized surgical packs that are used during surgeries of the spine. The instruments will vary between institutions, but generally they contain a pair of Lempert rongeurs, various neurological curettes, periosteal elevators, and a Frazier-Ferguson suction tip.
SPONGES:
Laparotomy sponges are large sponges often used to keep externalized organs moist during a laparotomy and thorocotomy procedures. Smaller sponges such as 3 x 3 sponges are used in most small animal procedures. It is important that all sponges be counted before and after surgery, to ensure that none are left within the patient. Manufacturers have developed radiopaque markers on sponges that allow for radiographic detection.
STAINLESS STEEL WIRE:
Stainless steel wire is commonly used during fracture repair to temporarily or permanently appose and compress bony fragments. Full and hemi-cerclage wires are most commonly used. Standard wire can be twisted around the bone with wire twisting forceps (or other wire twisters) whereas eyed cerclage wire requires the use of a specialized wire tightener for application.
- Eyed Cerclage Wire:
The eyed cerclage wire is commonly used during fracture repair to temporarily or permanently appose and compress bony fragments. This wire requires the use of a specialized wire tightener.
- Standard Cerclage Wire:
Standard cerclage wire is composed of stainless steel and is commonly used during fracture repair to temporarily or permanently appose and compress bony fragments. This wire can be wrapped around the fractured bone and twisted using a variety of tools, including wire twisting forceps.
SUCTION TIPS:
Suction is used to remove small or large amounts of fluid from a surgical site as it is more efficient than sponging.
- Yankauer:
The Yankauer suction tip is an appropriate choice during thoracic and abdominal surgery. I find this instrument helpful when delicate and localized suction is necessary.
- Frazier-Ferguson:
Frazier-Ferguson suction tips are designed to allow the surgeon to control the amount of suction delivered at the tip by covering or not the decompression hole located near its handle. This suction tip is often used during neurosurgical procedures where strong suction could damage spinal cord tissue.
- Poole:
The Poole suction tip has numerous fenestrations around the tip and the length of the instrument. This suction tip is especially useful to suction large amounts of fluid from the abdominal cavity since the multiple fenestrations reduce the likelihood of omental plugging. Disposable Poole suction tubes are also available.
- Flexible/Dental:
A variety of disposible suction tips are available. Flexible (dental) suction tips are useful for hard to reach areas when performing delicate procedures.
WIRE TIGHTENER/TWISTERS:
Wire tighteners are used with eyed cerclage wire; the wire is placed around the bone and free end is passed through the eye. The wire is then inserted through the shaft and the crank of the tightener. The crank is turned to tighten the cerclage wire to a desired tension, and the entire instrument is then used to bend the wire over, forming a looped knot in order to maintain the tension.
Wire twisters are used with standard cerclage wire, they create a twisted knot that is more slip resistant than looped knots, but typically lose tension when they are bent over or cut.
WIRE PASSER:
A wire passer is used to insert a cerclage wire around a bone with minimal disruption of the soft tissue. The wire passer is inserted at the site of cerclage wire placement, directly against the periosteum of the bone. The clerclage wire is then inserted through a hole at one end of the wire passer and the wire passer is removed, leaving the cerclage wire in its place.