Teknik operasi orif femur
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Transcript of Teknik operasi orif femur
Teknik ORIF Teknik ORIF Shaft FemurShaft Femur
Azis Aimaduddin AI
Skin incision An incision is made along an imaginary line between the lateral femoral epicondyle and the greater trochanter, along the length of the femur required by the specific fracture pattern.
Opening the fascia lata
The fascia lata is incised with a scalpel and split with scissors parallel to the skin incision, along its fibers.
The muscle fascia over the vastus lateralis is exposed.
SEPARATION OF VASTUS LATERALIS FROM FASCIA LATA
In the next step, the vastus lateralis is separated by blunt dissection from the fascia lata.
Incision of the fascia vastus lateralis
The vastus lateralis is now retracted anteromedially.
The muscle fascia investing the vastus lateralis is incised about 1 cm anterior to the intermuscular septum.
Mobilization of vastus lateralis from intermuscular septum
The muscle is detached from the lateral intermuscular septum and the linea aspera with a periosteal elevator.
Ligation of perforating vessels
The perforating vessel bundles must be identified.These vessels perforate the lateral intermuscular septum from the posterior side and run anteriorly, remaining closely applied to the femoral shaft.
Larger vessel bundles must be ligated, smaller ones can be alternatively cauterized with the diathermy.
Exposure of the bone After further detachment of the vastus
lateralis, using the elevator, the femoral shaft is exposed extraperiosteally
Exposure of the proximal femoral shaft If exposure of the proximal femoral shaft is necessary, mostly only for subtrochanteric fractures, the origin of the vastus lateralis must be identified.The muscle is retracted anteriorly and an L-shaped incision is made down to the bone. The muscle origin is then dissected off with the
periosteal elevator.
The proximal femoral shaft is exposed after the L-shaped detachment of the vastus lateralis has been performed. The vertical part of the incision lies in the interval between gluteus medius and vastus lateralis.
ORIF plate ORIF plate Compression plating provides fixation with
absolute stability for two-part fracture patterns, where the bone fragments can be compressed.
Compression plating can only be applied by an open procedure.
The objective of compression plating is to produce absolute stability, eliminating all interfragmentary motion.
Dynamic compression principle Compression of the fracture is usually produced by eccentric screw placement at one or more of the dynamic compression plate holes.
The screw head slides down the inclined plate hole as it is tightened, with the head forcing the plate to move along the bone, thereby compressing the fracture.
Plate position on the femur / tension band principle As a general rule the plate should be positioned on the lateral aspect of the femur.A plate acts as a dynamic tension band when applied to the tension side of the bone and when stable cortical contact is present on the opposite side to the plate.With vertical load, the curved femur creates a tension force laterally and a compression force medially.A plate positioned on the side of the tensile force resists it at the fracture site, provided there is stable cortical contact opposite to the plate.
Plate selection
For an A3-type fracture of the femoral shaft, at least three bicortical screws must be inserted into each fragment. Preferably, a nine-hole broad 4.5 mm plate is chosen. In this way, the second to the last screw hole at each plate end, as well as one plate hole over the fracture, can be left unoccupied.
Reduction
After extraperiosteal exposure of the lateral aspect of the femur, the direct reduction is carried out by using manual traction/traction table, and/or bone reduction forceps. With purely transverse fractures, it is rarely possible to achieve reduction by forceful longitudinal traction alone. It is usually necessary to increase the angulation (apex anteriorly) to reduce the posterior cortices, and then straighten the bone to reduce the whole fracture
Anatomical fracture reduction can be observed directly.
The plate will be positioned on the lateral aspect of the femur.
Contouring the plate
Fitting the plate to the bone Depending on the planned plate location, some contouring of the plate may become necessary. This applies distally as well as proximally.Contouring is aided by a stable provisional reduction and a malleable template that can be shaped along the bone surface. The malleated template is then used as a guide for shaping the plate to the bone.
Drilling for the first screw The first screw hole is drilled close to the fracture site. Its depth is measured through the plate, and tapping is required if non self-tapping screws are used.
Fixation of the plate with a first screw The plate should be attached with one screw to the predrilled fragment. The screw should not be tightened completely. The surgeon should check that the plate fits properly and that the alignment as well as the fracture reduction are adequate. Next proceed to drill the other fragment
Insert a second screw eccentrically A second screw is inserted eccentrically into the other fragment, near the fracture
Tighten screws to compress fracture As shown in this illustration, tightening the eccentrically placed screw compresses the fracture by pulling the proximal fragment towards the fracture.It should be confirmed that the fracture surfaces are anatomically reduced, and that both ends of the plate fit satisfactorily.Both screws should be tightened, and the reduction should be secured and compressed satisfactorily.
Finish screw insertion The remaining screws are inserted.If the femur has a strong cortex, three cortical screws should be sufficient in each fracture fragment. In case of an osteoporotic bone, it may be safer to fill all screw holes.
Reduction
General considerations In more proximal fractures, due to the pull of the iliopsoas muscle, the upper main fragment may be flexed and externally rotated, and the distal segment lies posteriorly due to gravity.Several options for fracture reduction can be considered:Elevation of the distal fragment by use of a crutch.Lowering of the proximal fragment by external pressure from a mallet.A wrap around the femur.A Schanz screw inserted into one of the fragments.Use of a bone hook.(Manual reduction)
The proximal fragment may be flexed and externally rotated by the iliopsoas muscle.
Elevation of the distal fragment by use of a crutch This option may only be used if the patient is on traction. A crutch is slid beneath the distal main fragment in order to elevate it to the level of the proximal fragment.
Lowering of the proximal fragment by external pressure from a mallet Firm manual pressure is usually required to achieve fracture reduction
A wrap around the femur Based on the nature of the fracture, the wrap is usually placed around the larger fragment.Reducing the fracture using a wrap
A Schanz screw inserted into one of the fragments A monocortical Schanz screw (preferably 5 mm) can be helpful for providing direct control of the displaced fragments. It is superior to reduction maneuvers through the skin.
Bone hook Direct reduction with a bone hook may be helpful for securing an anatomic alignment. Careful insertion and manipulation must be performed, in order to minimize soft-tissue trauma and to prevent injury to the femoral artery.
Reduction using a bone hook.
Manual reduction Manual reduction may be attempted, but radiation of the surgeon‘s hands may be unavoidable.
Guide wire insertion A guide wire is advanced into the distal main fragment until it is about 5 mm proximal to the intercondylar notch. It is important that the guide wire be centered in order to prevent eccentric reaming and subsequent malposition of the nail, which can result in varus/valgus/antecurvatum/retrocurvatum malalignment.
Unreamed nailing does not require a guide wire. When unreamed nailing is performed, the nail is used as a reduction tool.
To ensure maintenance of alignment of the K-wire throughout the reaming process, it may be gently be tapped in order to provide purchase in the cancellous subchondral bone. If this is not achieved, the guide wire may displace on removal and exchange of the reamers.
Nail diameter It is important to measure the medullary diameter at the mid portion of the femur, which represents the narrowest segment of the medullary canal.The inner cortical edge should touch with the inner numbered disk of the ruler aperture. In the illustration an inner cortical diameter of 14 mm is shown.
Reaming
Insertion of reaming rod After the tissue protector has been introduced, the reaming shaft, fitted with the first reamer head, is inserted over the guide wire. Usually reaming begins with a 9 mm medullary reamer.
SEQUENTIAL REAMER SIZE INCREASE
Reaming is performed in sequential steps by increments of 0.5 mm each.
As soon as chatter from cancellous bone can be felt and heard, the inner cortex has been reached. This may not be the case in segmental fractures or when severe comminution is present.
Adequate reaming must be performed in order to allow for smooth nail insertion. For example, for a nail width of 10 mm, drill bits of up to 10.5 or 11 mm diameter are used. If a very tight fit of the reamer can be detected before the desired reaming size is reached, one should consider using a smaller nail than previously planned.
Pitfalls: eccentric and overaggressive reaming Eccentric reamingEccentric reaming can cause weakening of the adjacent cortex which may interfere with healing or even cause a fatigue fracture.Trapping of reamer by slow spinningIf the reamer becomes trapped while reaming, it must be gently removed by the most senior surgeon, because breakage of the reamer tip in this situation can be a devastating complication.Heat necrosis by overaggressive reamingOveraggressive reaming should be avoided because it may cause heat necrosis of the femoral canal. This applies especially for narrow midshaft canals (9 mm or less in diameter).
Rapid thrusting/systemic fat embolizationCare should be taken to use sharp reamers, to advance the reamers slowly, and to allow sufficient time between reaming steps in order for the intramedullary pressure to normalize.
Rapid thrusting of the reamer may worsen the intramedullary pressure increase that is observed during nailing. This image demonstrates fat extrusion in a human cadaver specimen with a window in the proximal section.
This may cause pulmonary embolization of medullary fat, which in turn may lead to pulmonary dysfunction (lower image in the enlarged view shows an example of fat embolization through the right atrium).
Nail insertion
Connecting handle to nail The insertion handle is connected to the nail by the corresponding connecting screw. It is attached using the hexagonal screwdriver through the hole in the insertion handle. It is recommended that the nail be inserted manually and rotated about 90 degrees from its point of entry to its finalorientation.
Introduction of nail Under control with the image intensifier, the nail is pushed down as far as the fracture zone. After the driving cap has been fixed to the insertion handle, the nail is further advanced into the medullary cavity by gentle hammer blows, whilst verifying the position of the tip of the nail under the image intensifier.In this intraoperative view, the nail is about to pass the fracture site in the intensifier image.
In this intraoperative view an unreamed nail is inserted and the external fixator is used as a joystick to help to reduce the fracture anatomically.
Once past the fracture, the nail is advanced by hand or by gentle hammer blows.
Passing the fracture zone It is important that the tip of the nail does not become trapped in the distal main fragment because blow out fractures can occur. Each gentle hammer blow should advance the nail. Do not force the nail through a tight canal – if necessary, re-ream to another 0.5 mm diameter.In many cases, the nail will help to align the fracture.
Nail locking
General considerations Purpose of lockingLocking was developed in order to provide and maintain rotational stability and length. It can also be used to finalize fracture reduction.
Assessment of alignment Before the patient is moved from the fracture table, rotation of the leg is observed clinically and compared to the contralateral leg. With the femur now stable, it is possible to perform a thorough examination of the knee joint to rule out additional ligamentous injuries.
Wound closure and assessment of alignment
Wound closure The procedure ends with the closure of the fascia and the skin as separate layers.
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