Preoperative planning has always been a significant component of the complete strategy of fracture care by surgical intervention.
Preoperative planning enables the surgeon to perform the operation in his mind prior to the actual surgical procedure. It gives him an opportunity to prepare the equipment that might be needed and allows him to plan the steps of the operation, including the location of the incisions, choice of trauma implants, reduction technique and techniques of application.
With preoperative planning the orthopedic surgeon is better prepared for surgery, therefore ensuring a higher chance of success as well as avoiding possible complications. Another benefit is that the surgeon may provide the patient with a detailed explanation of the operation so that he may obtain informed consent and forge a good patient-surgeon relationship.
Planning in MIPO
In MIPO, preoperative planning plays an even more important role. Since the fracture sites aren’t visualized or exposed, the surgeon must plan each step of the surgical procedure to make sure that the operation proceeds smoothly, precious time isn’t wasted, and that unnecessary exposure to irradiation is prevented.
The following guidelines can be helpful in the decision-making process as well as the preparation of a preoperative plan for MIPO.
Appropriate assessment of the patient and the injury is essential for correct decision making. This includes a detailed history, relevant laboratory tests, a careful physical examination, x-rays, and other ancillary imaging studies if specified.
Patient factors that need to be considered in the decision-making process include:
- Post-trauma status including hemodynamic stability
- Future expectations
- Patient compliance
- General medical status and comorbidities
- Quality of bone
- Preinjury functional status
- Patient compliance
- Future expectations
This evaluation aids to decide whether the patient is an appropriate candidate for surgery and is fit for anesthesia.
For proper assessment of the fracture, good quality x-rays are essential. Traction films are beneficial in some instances. Other imaging studies that can be helpful include CT scans, MRI, 3-D reconstructions, and vascular studies.
The fracture factors that should be taken into consideration include:
- Duration after injury
- Closed open fracture
- Simple, wedge or complex
- Associated fractures
- Location- articular, metaphyseal or diaphyseal
- Condition of the skin and soft tissues
- Neurovascular injuries
- Associated injuries
Good indications for MIPO are complex or multifragmentary fractures of the metaphysis and diaphysis and fractures of intraarticular with extension into the diaphysis.
Relative indications are simple diaphyseal fractures and some open fractures.
Graphic preoperative plan
One of the necessities of a good preoperative plan is to make a graphic representation of the fracture fragments, manipulating the fragments on paper to attain a reduction, selecting the suitable orthopedic implants and superimposing them on the reduced fracture utilizing templates, and reviewing the plan to see whether the desired result is attained.
To prepare the preoperative plan, the following are important:
- X-rays of good quality, including views of the normal side if possible
- Tracing paper (or transparencies)
- Colored felt-tipped pens and pencils
- Additional imaging such as CT scans (especially for intra-articular fractures)
- Relevant implant templates of the correct scale
- A goniometer
The following planning techniques are usually used.
- Direct overlay
- Use of the physiological axes for articular fractures
- Overlay using the normal side
Distal Femur is the part of thighbone above Knee joint, which pans out like an inverted funnel. A fracture in this bone is termed a Distal Femur Fracture.
Such fractures commonly occur in people whose bones are weak due to old age, or in younger people who have suffered high energy injuries like a car crash. In both, the elderly and the young, the injury may extend into the knee joint and may shatter the bone into many pieces.
The largest weight-bearing joint in the body is the Knee. While distal femur bone makes up the top part of the knee, the upper part of Tibia bone supports the bottom part of the knee joint.
Articular cartilage, a smooth, slippery substance covers the ends of the femur. When we bend or straighten our knee, this cartilage protects and cushions the bone.
Normal knee anatomy
Knee Joint is supported by strong muscles. Muscle in the front of our thigh is called Quadriceps, while the one at the back of thigh is Hamstrings. Apart from supporting, they also allow us to bend and straighten our knee.
There are different types of Distal Femur Fractures. The bone may break in transverse plane or into many pieces (comminuted fracture). Sometimes the fracture may extend into the knee joint and separate the surface of the bone into a few (or many) parts. Such fractures are called intra-articular. Due to damage to the cartilage surface of the bone, intra-articular fractures can be more difficult to treat.
Various fracture types of distal femur:
(Left) A transverse fracture across the distal femur.
(Center) An intra-articular fracture that extends into the knee joint.
(Right) A comminuted fracture that extends into the knee joint and upwards into the femoral shaft.
Distal femur fractures can be closed — if the skin is intact — or can be open. An open fracture is when a bone breaks in such a way that bone fragments stick out through the skin or a wound penetrates down to the broken bone.
Open fractures often have associated damage to the surrounding muscles, tendons, and ligaments. Thus, they have a higher risk of complications and take a longer time to heal.
The hamstrings and quadriceps muscles, both tend to contract and shorten when the distal femur breaks. In such case, the bone fragments change position and it is difficult to line up with a cast.
Distal femur fracture in which the bones are out of alignment
In this x-ray of the knee taken from the side, the muscles at the front and back of the thigh have shortened and pulled the broken pieces of bone out of alignment.
As discussed earlier, Fractures of distal femur occur mostly in younger people (under age 50) or the elderly.
Younger patients suffer high energy injuries usually caused by falls from significant heights or motor vehicle collisions. Due to the high energy impact, many patients also often have injuries of the head, chest, abdomen, pelvis, spine, and other limbs.
In Elderly people, with age the bone quality becomes poor. Bone become thinner and become very weak and fragile. A lower-force impact, like a fall from standing, can also cause a distal femur fracture. Although elderly patients do not often have other injuries, they may have concerning medical problems, such as conditions of the heart, lungs, and kidneys, and diabetes.
The most common symptoms of distal femur fracture include:
Pain with weight-bearing
Swelling and bruising
Tenderness to touch
Deformity — the knee may look “out of place” and the leg may appear shorter and crooked
While in majority of cases, these symptoms occur around the knee, but there may also be symptoms in the thigh area.
The following are some general guidelines when using these implants for Locking compression plate-LCP
- Whenever possible, the fracture is first reduced by indirect means.
- If required, the reduction is then maintained using external fixators or distractors.
- If a well-contoured or anatomically preshaped plate is utilized, the implant may be used as a reduction aid when utilized with standard screws.
- If the compression purpose of the LCP is to be utilized, for example in simple transverse fractures, correct contouring of the plate is first performed; axial compression may then be carried out utilizing standard screws in the dynamic compression unit of the combination holes. It’s significant to note that the LCP combination holes are arranged asymmetrically on the plate. This asymmetry enables axial dynamic compression to be exerted unidirectionally. After exerting axial compression by the standard screws, further LHS may then be inserted.
- If it’s desired to apply interfragmentary compression in spiral or simple oblique fractures, this should first be accomplished utilizing standard screws as lag screws prior the application of LHS.
- To insert standard screws, the universal drill guide is utilized. The screw holes are predrilled, either eccentrically or neutrally, depending on the screw’s intended function. The depth of the screw hole is then measured as well as tapped, and the suitable standard screw inserted.
- If plate contouring is required, it should be performed using the suitable bending instruments. Bending should be done between the combination holes and not done through the holes as this can cause deformation of the holes and lead to difficulty in the following insertion of LHS. One way of preventing this deformation is to insert an LHS or a threaded drill sleeve into the threaded portion of the combination hole before carrying out the bending.
- If wanted, an LCP spacer be screwed into the plate before its insertion. The spacer ensures a gap of 2 mm between the plate and underlying cortex, therefore minimizing plate-bone contact and preserving periosteal circulation. This spacer may be removed after insertion of the LHS.
- Skin incisions are made, corresponding in location to the ends of the plate.
- A tunneler can be used to create a submuscular extra-periosteal tunnel for the bone plate.
- The bone plate is then passed into the tunnel. This may be done in one of many ways. If a tunneler is utilized, one end of the plate is tied with a suture to the end of the tunneler. As the tunneler is withdrawn, the bone plate is pulled into position. Another way is to fix plate’s one end with a plate holder or a threaded LCP drill guide which is then utilized to guide the plate into position along the track made by the tunneler.
- Once the plate is in place, bone screw insertion may follow. If the first inserted bone screw is an LHS, before locking, the other end of the plate should be temporarily stabilized with either a standard screw, a K-wire, a threaded LCP drill guide, or another LHS that isn’t locked. This is to avoid the plate from rotating and causing damage to the surrounding soft tissue as the 1st LHS is tightened and locked.
- If the equally of fracture reduction satisfactory, the rest of the LHS are inserted.
- To insert a self-tapping LHS percutaneously, a threaded LCP drill guide is 1st introduced through a stab incision in the skin, and then screwed into the threaded part of the selected combination hole. The drill guide makes sure that drilling is done in the accurate direction so that the screw is appropriately locked to attain maximal angular stability. The screw hole is then drilled and measured, and the suitable LHS inserted, first utilizing a power tool with the screwdriver shaft and then performing the final tightening by hand with the torque-limiting until clicking happens.
- Predrilling and depth measurement aren’t essential if a self-drilling, self-tapping LHS is used monocortically. This, though, is only possible in good-quality bone with a thick cortex. Monocortical screw fixation is also specified in periprosthetic fractures.
There are two bones in the forearm – radius and the ulna. When one or both the bones of the forearm have a fracture, we term it as Forearm Fracture. Both bones are important not only for proper motion of the elbow and wrist joints but also serve as important attachments to muscles of the upper extremity.
A most common reason for fractures is due to a fall on the hand, or a direct blow to the forearm (commonly seen in altercations, sports injuries, and car accidents). Pain, swelling, and deformity of the forearm indicate a forearm fracture. Proper diagnosis can be made with physical examination and x-ray studies.
Radial shaft fractures, ulnar shaft fractures, and fractures of both forearm bones are discussed below. Siora Surgicals has manufacture locking implants for hand fracture. Other Fractures that occur around the elbow (radial head fractures and olecranon fractures) and those that occur around the wrist (wrist fractures), will be covered separately.
Radial Shaft Fractures
It is not common to suffer an isolated fracture of the radial shaft. Most fractures of the radial shaft are associated with injury to the ulna (see ‘both bones forearm fracture’ below) or injury to one of the joints around the wrist (Galeazzi fracture).
An isolated radial shaft fracture, if it occurs, commonly requires surgery unless the fracture is non-displaced. If the fracture is out of position, then fracture is realigned to allow forearm rotation. Hence, surgery is the preferred treatment option to realign and hold the bones in the proper position.
Ulnar Shaft Fractures
An isolated fracture to the ulna is most often caused during an altercation and is called a “nightstick” fracture. Raising of the forearm in a protective posture exposes the ulna bone, which can be damaged by a blunt traumatic hit. The name is derived from the defensive gesture of people trying to shield themselves from a policeman’s nightstick leading to ulnar fractures.
If the fracture is well aligned, an isolated ulna fracture can be treated with immobilization in a cast. However, if the fracture is badly displaced, or the skin is broken causing an open fracture, then surgical treatment is advised.
Both Bones Forearm Fracture
Fracture of Both bones almost always require surgery in an adult patient. Without surgery, the forearm is generally unstable and to cast this type of fracture in a proper orientation is very difficult if possible. In younger children, nonsurgical treatment can be considered, but in adolescents, surgery may have to be carried out.
Fractures of both bones of the forearm are most commonly treated by fixing a metal plate and screws on both the radius and ulna bones. These bones have to be approached through a separate incision, necessitating, therefore, you will have two incisions on your forearm. Some surgeons may use a rod within the bone to maintain the position of the bone, but this cannot be done in fractures where rotational stability is required. Hence, both bones forearm fractures are mostly treated with plate and screws.
Complications of Forearm Fractures
The complications that are commonly encountered in such fractures include:
- Limited Motion: After the treatment of forearm fractures, decreased motion capability is common. It can be limited in the elbow and wrist joints but is most commonly noticed in forearm rotation (i.e. opening a jar or turning a door handle).
- Non-Healing Fracture: Due to inadequate healing of the bones of the forearm, there may be persistent pain. In open Fractures or where the bone is lost (i.e. many small pieces), this problem is more likely to occur. In such cases, repeat surgery for bone grafting may be necessary.
- Infection: Post-surgery, possibility of Infection is common. An infection in forearm fracture after surgery may require removal of the metal plate and screws to cure the infection.
Painful Hardware: Many times, the metal implants used during surgery can be felt under the skin and are painful. They can be removed, after the bone has properly united, usually at least a year after surgery.
The overview of the internal fixator has made MIPO a more practical theory and expanded its scope and range of applications.
The internal fixator is a submuscular or subcutaneously positioned external fixator. The design feature that is unique of the internal fixator is the locking head screw (LHS)- the screw head incorporates a double conical thread for safe fixation into a corresponding conical thread in the hole of the plate. This characteristic imparts a degree of angular stability to the construct because the locked screw head can no longer toggle within the plate hole. Also, because the screw head is secured within the plate hole, it doesn’t press the plate against the underlying bone as the screw is tightened, in contrast to standard screws such as cancellous or cortex bone screws.
The internal fixator, therefore, possesses characteristics that make it suitable for MIPO. These include:
- LHS which prevent the bone plate from being pressed against the underlying bone, therefore sparing the periosteal blood supply.
- Since the bone isn’t pulled against the plate by the LHS because the bone screws are tightened, there is no loss of primary reduction if the fracture has previously been reduced.
- Consequently, correct contouring of the plate isn’t necessary, a definite benefit in MIPO as the bone isn’t exposed for templating.
- Angular stability of the construct also avoids secondary loss of fracture’s reduction when placed under load.
- As the LHS are either self-tapping and self-drilling or only self-tapping, application of screw is made easier in the MIPO setting as drilling and/or tapping is no longer needed as is the situation with the application of standard screws.
The 1st internal fixator specifically intended for use in MIPO was the less invasive stabilization system (LISS) for the distal femur. As the benefits of the LISS became apparent, demand for a more versatile system risen, and this result in the development of the locking compression plate (LCP) with a specially intended combination hole, one half of which is intended as a dynamic compression until that enables the use of standard screws for interfragmentary or axial compression, while the other half is threaded to enable the application of LHS. Therefore, the LCP may function as a compression plate or as an internal fixator when only LHS are utilized.
In theory, no contouring of the LCP is essential when used as an internal fixator, however in practice, some degree of contouring is usually required, especially in the bone’s epi-metaphyseal segments. Otherwise, the plate can stand proud and become prominent subcutaneously or cause irritation of the adjacent soft tissue. To overcome this issue, specially intended metaphyseal plates were introduced. The special characteristics of this plate are that the juxta-articular end of the plate is thinned out to aid contouring and the two distal holes in this thinned part of the plate are angled at 11⁰ toward the center of the plate to enable optimal application of the LHS in the epiphyseal part in order to avoid penetration of the articular surface. A further refinement of this is the progress of anatomically preshaped LCP for use in specific epi-metaphyseal portions of the skeleton. The metaphyseal end of such a plate enables the insertion of a cluster of LHS in a convergent or divergent manner to improve their pull-strength. Additionally, no contouring of the plate is usually required. An added benefit of this anatomical preshaped LCP is that they may be used as an aid for indirect fracture reduction when utilized with standard screws. These may draw the bone toward the plate and therefore effect an adaptation of the bony fragments to the shape of the bone plate. Examples of anatomically preshaped LCP are the LCP distal humerus, locking proximal humerus plate (LPHP), LCP distal radius, LCP distal femur, LCP distal tibia, and LCP proximal lateral tibia.