ORIF of the Tibia and Fibula - Research Paper Example

?ORIF of the Tibia and Fibula By Fractures of the tibia and fibula may occur at any age but is most common during adolescence and active adulthood. Among all fractures in the long bones, the highest incidence of nonunion occurs with tibial shaft fractures. In addition, open tibia fracture also has the highest rate of infection. Furthermore, an isolated fracture of either fibula or tibia is uncommon, although it can occur with a direct blow to the side of the lower leg or as an indirect injury such as a torsional movement, respectively. On the other hand, injury mechanisms range from low- energy rotational injuries to violent, high- energy injuries, as in vehicular accidents. These are clearly different injuries with different types and incidences of complications, different rates of healing and in many cases very different goals of treatment (Doherty 1144). The degree of trauma itself dictates whether or not surgical intervention is necessary in each case. Surgical approaches in the management of fractures radically depend on a variety of factors such as age, general health condition and degree of bone trauma. In fact, modern orthopedics is plagued with arguments of different experts as to the relative efficiency of surgical techniques based on the incidence of infection, non union and delayed union, soft tissue involvement, and estimated duration of rehabilitation. Meanwhile, Open Reduction with Internal Fixation (ORIF) is a novel surgical approach in lower leg fractures. Considerations Indications: Absolute indications for surgical treatment with ORIF plating include open fractures, short oblique shaft fractures with associated comminution, transverse shaft fracture, fractures of the shaft with displaced intraarticular fracture of the knee and ankle, fractures with associated nerve or vascular injury, or fractures with associated compartment syndrome (Doherty 1149). Acute compartment syndrome can be caused by increased pressure in a closed fascial space, compromising perfusion of nerves and muscles. The increase in pressure interferes with the blood supply of the tissues inside that compartment. Clinical signs include swelling and palpable tenseness over a muscle compartment, paresthesias, pallor, pulselessness, and paralysis. Once compartment syndrome is detected, an emergency surgery should be performed since severe ischemia may lead to muscle and nerve death. Relative indications for surgical treatment with ORIF plating include multiple injury patients, and patients with compromised soft tissue around the fracture site. Contraindications: ORIF is contraindicated when there is not enough evidence that the client can tolerate the surgical experience, such as no cardiopulmonary clearance from a cardiologist and other recommendation documents from the primary care physician and other specialists. Furthermore, it may also be contraindicated when there are fracture blisters due to significant soft tissue damage, nonviable soft tissue envelope, and acute open fractures with gross contamination. On the other hand, majority of tibia fractures are now treated with intramedullary fixation because this form of treatment allows early functional rehabilitation of the knee and ankle, permits early weight- bearing, and imposes the lowest risk of infection and soft tissue complications. Also, application of external fixators can also help stabilize the fracture while allowing soft tissue repair. The physician carefully evaluates the patient so that the most appropriate procedure is performed. Tests: As with most orthopedic cases, frequent radiographic studies are needed in order to establish an exact diagnosis, guide appropriate treatment, prevent unnecessary surgical interventions, and monitor client response to treatment. Specifically, x- rays in the anteroposterior, lateral and oblique projections of the entire lower leg are needed, including both the knee and ankle joints. A CT scan may be needed if the client is suspected to have other injuries aside from the bones in the lower legs, such as involvement of the bones of the feet. Normally, the bones should have an intact integrity and in a normal alignment. As for any client undergoing surgery, a complete blood count should include the hemoglobin level (which is frequently lower after bleeding associated with trauma) and the white blood cell count (which is elevated in acute infections, trauma, and acute hemorrhage). Before surgery, coagulation studies are performed to detect bleeding tendencies (because bone is very vascular tissue). Infection should be managed carefully so as not to interfere with the normal wound and bone healing processes. With fractures, creatine kinase (CK) and lactate dehydrogenase (LDH) values elevate as a result of muscle trauma. Incisions: Whether the fracture occurs only in tibia or fibula or both, the incision made over the fracture site must be straight and longitudinal. This is preferably done so as not to cause unnecessary transverse cuts to the muscles and blood vessels. Muscle structures are retracted to expose the fracture. The periosteum (which is a protective connective tissue covering of the shaft) is stripped at the fracture site just enough to allow plate application. Too much stripping of the periosteum will interfere with the blood supply to the bone at the fracture site. Other considerations: If possible, the surgery might be delayed to stabilize the client’s condition and reduce the surrounding tissue inflammation. However, it should be performed before surrounding muscles become contracted and atrophied and serious structural abnormalities occur. The decision on timing is therefore complex and requires that each fracture be evaluated on a case- by- case basis. Significantly traumatized, yet closed, soft tissue envelope should delay surgical fixation until swelling has decreased and any blisters in the surgical incision site are re- epithelialized (Bucholz 1999). Many patients donate their own blood during the weeks preceding their surgery. This blood is used to replace blood lost during surgery. Autologous blood transfusions eliminate many of the risks of transfusion therapy. Also, during surgery blood is conserved to minimize loss. A pneumatic tourniquet may be applied after exsanguination of the limb with bandages to produce a “bloodless field.” Intraoperative blood salvage with reinfusion is used when a large volume of blood loss is anticipated. Postoperative blood salvage with intermittent autotransfusion also reduces the need for blood transfusion. Normal bone healing occurs as follows: Stage one – formation of a hematoma (13 days) Blood clot forms and surrounds damaged structures, provides primitive cells for bone healing. Stage two – granulation (3 days- 2 weeks) Formation of tissue, granular in appearance, containing blood vessels, fibroblasts, osteoblasts. Stage three – callus formation (26 weeks) Maturation of granulation tissue into scaffolding of mineralized bone matrix and collagen. Stage four – ossification of consolidation (3 weeks- 6 months) Osteoblasts and fibroblasts continue to multiply, bridging gaps in bone (culminating in union). Stage five – return of the bone to preinjury state (remodeling) Differential resorption of bone along lines of stress, reestablish of medullary canal, return of bone to preinjury state. When fractures are treated with open rigid compression plate fixation techniques, the bony fragments can be placed in direct contact. Primary bone healing occurs through cortical bone (Haversian) remodeling. Little or no cartilaginous callus develops. Immature bone develops from the endosteum. There is an intensive regeneration of new osteons, which develop in the fracture line by a process similar to normal bone maintenance. Fracture strength is obtained when the new osteons have become established. Serial x-ray films are used to monitor the progress of bone healing. The type of bone fractured, the adequacy of blood supply, the surface contact of the fragments, and the general health of the person influence the rate of fracture healing. Adequate immobilization is essential until there is x-ray evidence of bone formation with ossification. Internal fixation devices (metallic pins, wires, screws, plates, nails, or rods) ensure firm approximation and fixation of the bony fragments until ossification occurs. Incisional Anatomy For tibia and fibula surgery, incisions are to be made longitudinally on the medial side (tibia) or lateral side (fibula). Using a sharp knife, the incision is made perpendicular to the skin. The skin receives significant blood supply from the underlying fascia by way of small perforating arteries. These are disrupted by subcutaneous dissection or degloving injuries, which separate the subcutaneous fat from the underlying fascia. Therefore, dissection should proceed beneath, rather than superficial to, the deep fascia so as to decrease the risk of skin necrosis and take advantage of the subfascial arterial plexus, which is raised raised off the underlying muscle with the fascia. The dermal plexus is the terminal vascular bed of the skin. Its patency and perfusion are demonstrated clearly by puncture bleeding after tangential excision of a split- thickness layer of skin. A significant development has been the development of fasciocutaneous flaps, nourished by local vessels, often those accompanying superficial sensory nerves (Browner et. al 2324). After the skin is incised, the subcutaneous tissue should be visible. This fatty layer can be very thick especially in obese client, except over the malleolus, which appears to be superficial. There is very little subcutaneous dissection distally (Morrey and Morrey 225). Usually, the subcutaneous layer is not dissected from the skin, because this might cut off its vascular supply. Deep next to the subcutaneous layer is the fascia. This layer separates the subcutaneous with the muscular layer. The fascia is a tough fibrous tissue, which acts to increase the force of muscle contractions. In the deeper areas of incision, dissection is done in a gentle blunt technique. Surgical Anatomy Tibia and Fibula: The tibia and fibula form the skeleton of the leg. The tibia is larger and more medial. It is considered as the weight- bearing. It articulates with the condyles of the femur superiorly and the talus (ankle bone) inferiorly. Muscles such as the tibialis anterior, tibialis posterior, and the flexor digitorum longus are attached to the tibia. On the other hand, the fibula does not have a weight- bearing function. It is attached to the tibia through the interosseous membrane. It is not part of the knee joint and is mainly for the attachment of muscles: the peroneal, extensor digitorum, flex hallucis longus and the tibialis posterior. It also forms the lateral malleolus at the ankle and thus provides additional stability. Basically, the structures of tibia and fibula are similar with other long bones of the body. The entire length of the bone is called diaphysis, while both proximal and distal ends are called epiphyses. Metaphysis is the flared region of bone between the diaphysis and epiphysis. This is the growing portion, which has the greatest area of blood supply. Epiphyseal plate is the area between the metaphysis and epiphysis, which allows for growth in cartilage and length of bone. Specifically, the diaphysis is covered and protected by a fibrous connective tissue membrane called periosteum. This periosteum also covers the nutrient arteries and nerve supply. The epiphysis consists of a thin layer of compact bone enclosing an area filled with spongy bone. Articular cartilage covers its external surfaces instead of periosteum. This hyaline covering is primarily important in decreasing friction at joint surfaces. Removal of a portion of the fibula decreases but does not abolish tension strain on the tibia’s anterior surfaces. The fibular shaft is a significant muscle origin. The distal end of the fibula, or lateral malleolus, has a major role in the structural integrity of the ankle joint. It is securely attached to the distal tibia through the ligaments of the ankle syndesmosis—the anterior and posterior distal tibiofibular ligaments, the inferior transverse ligament, and the interosseous membrance. Disruption of these ligaments, with resultant loss of fibular support for the talus, may occur in association with tibial shaft fractures; therefore, the integrity of the ankle joint should always be assessed in patient with tibial fractures. The tibia and fibula are surrounded by soft tissues that are most important in any consideration of injuries to this region. The surgeon who pays more attention to the bones than to these soft tissues may commit irretrievable errors in evaluating and treating fractures of the tibia and fibula. The soft tissue envelope of the leg is injured to a greater or lesser extent whenever a fracture occurs. Open wounds are usually obvious, though they may be small and underrepresent the extent of damage within. Subcutaneous degloving may soon result in extensive skin necrosis. Initially, hoever, such a wound can appear quite benign (Browner et. al. 2324). There are three muscular compartments in the lower leg: the anterior, lateral, and posterior compartments. The anterior compartment contains the tibialis anterior, which provides inversion and dorsiflexion of foot. Extensor digitorum longus provides toe extension. Extensor hallucis longus gives great toe extension and ankle dorsiflexion. Peroneus tertius provides eversion and dorsiflexion of foot. The deep peroneal nerve is also housed in this compartment which has a sensory distribution in the dorsal web space. The lateral compartment contains the peroneus longus, which provides plantar flexion, abduction and eversion of the foot. The superficial peroneal nerve runs in this compartment which is responsible for sensory distribution in the dorsal aspect of foot. The posterior muscle structures are superficial or deep. The superficial muscles are popliteus, which provides flexion and internal rotation of the leg. Plantaris provides foot plantar flexion. Soleus provides ankle plantar flexion. Gastrocneumius is knee flexion and gastrocnemius and soleus tendons unite to form the achilles tendon, which inserts on the posterior calcaneus. The deep muscles are the tibialis posterior, which provides inversion and plantar flexion of the foot. Flexor digitorum longus provides toe flexion and foot extension and flexor hallucis longus provides great toe flexion. The posterior tibial nerve in this compartment provides sensory function in the plantar surface of foot. Because such compartments are wrapped by strong septa, any trauma to the lower leg may pose significant risk on the integrity of each component. Pressure increases in these compartments as a result of tissue inflammation, accumulation of blood from the torn blood vessels, and adherence of bodily enzymes and other substances as a result of trauma. With increasing pressure, the blood supply can be shut off, causing severe tissue ischemia and nerve damage, which can start the vicious cycle leading to the development of a compartment syndrome. Compartment syndrome requires an emergency fasciotomy to reduce the pressure build- up in the affected compartment. Blood Supply: The popliteal artery trifurcates posterior to the knees as it branches to enter the anterior and posterior aspects of the leg. The posterior tibial artery enters the deep posterior compartment of the leg, traveling just posterior to the tibialis posterior muscle. The deep peroneal artery also runs in the deep compartment, lateral to the tibial nerve. The anterior tibial artery crosses superior to the interosseous membrane and travels just anterior to it. In the distal third of the leg it begins to proceed anteriorly (Morrey and Morrey 215). Nerve Supply: The saphenous nerve is the large sensory continuation of the femoral nerve, which innervates the medial aspect of the distal thigh around the level of Hunter’s canal and continues distally in a curvilinear pattern to provide sensation along the medial leg and proximal ankle. One of its larger branches, the infrapatellar branch of the saphenous nerve, crosses medially to laterally across the anterior aspect of the leg near the level of the inferior pole of the patella. This is frequently transected during the anterior approaches of the knee. The saphenous nerve travels primarily down the medial aspect of the leg on the medial head of the gastrocnemius, along with the greater saphenous vein. The tibial nerve runs in the deep posterior compartment, just lateral to the posterior tibial artery. The sural cutaneous nerve is a branch of the tibial nerve, which is located in the midline of the posterior aspect of the leg and is usually lateral to the small saphenous vein, supplying cutaneous branches through the fascia to the posterior aspect of the calf. The superficial peroneal nerve is one of two branches of the common peroneal nerve at the level of the proximal fibula. Along with innervating the muscles of the lateral compartment of the leg, the nerve continues to the dorsum of the foot after piercing the anterior fascial compartment (Morrey and Morrey 215). Patient preparation Preoperatively, informed consent should be obtained by the surgeon from the patient after a brief review and explanation about what is to be done and how the patient can help. Proper identification is verified by putting an identification wrist band, following the institution’s policy. The surgical assistant is usually asked to be present as a witness. The patient’s chart is checked for completeness of necessary cardiopulmonary clearance and updated lab values. Intravenous lines are checked for patency. The patient may also need to have urinary catheterization, depending on the surgeon’s orders. The patient is wheeled on a gourney to the OR. At the same time in the OR, equipment necessary for surgery are prepared and sterility is established. In ORIF, the number of personnel to assist the surgeon is usually greater than other surgical operations. Then the patient is transferred to the operating table and usually positioned supine, taking necessary precautions to prevent falls and other unnecessary injury. The unaffected limbs may need to be strapped securely. The anesthesiologist attaches a blood pressure cuff on the patient’s right arm and a pulse oximeter on the left middle finger. The patient is then put to sleep and general anesthesia is infused depending on the anesthesiologist’s preferences. The expected time duration of the surgery is an important point to be considered in choosing the appropriate anesthetic agents. Supplemental oxygen is administered via inhalation mask. After the general anesthesia is infused, a five- pound sand bag is placed on the ipsilateral buttock, flank, and shoulder region to maintain alignment by preventing external rotation. The ankle of the operative side may need to be stabilized using a sterile bump. To control bleeding, a 34- inch sterile tourniquet is placed on the mid thigh of the operative side. It is also important that x- ray results be placed on illuminated plates visible to the surgical team. Then the circulating nurse prepares the skin area from the toes to the mid- thigh using an antiseptic solution based on the agency’s standard protocol. After this, the surgeon and assistant are scrubbed, completely gowned and gloved. Lead aprons may also be worn by the patient and surgical team, in anticipation of radiological procedures to be performed intraoperatively. The surgeon and the assistant then drape the operative leg, exposing only the area to be manipulated in the procedure. The surgical technician also prepares by passing sterile handles on the overhead lights, and suction cords. The time of first incision is recorded by the circulating nurse. Surgical Procedure Incision: Using the #10 blade, the surgeon incises the skin longitudinally and parallel to the fibular fracture, or in an anteromedial incision around the medial malleolus in a curvilinear direction for a distal tibial fracture. When both tibia and fibula are fractured, it would be the surgeon’s preference on which bone to fix first. The surgeon ensures that incisions are centered over the fractured site based on the radiographic results. Major veins and arteries should be avoided with utmost care in every incision. The surgical assistant makes it sure that bleeders are meticulously detected using Raytec sponge. The surgeon then grasps the bleeders using the Adson forceps with teeth and the assistant touches the forceps with the bovie to cauterize the vessels. Surgery: It is very important to note that deep exploration of the lower leg bones and compartments should be made gentle and blunt dissection techniques should be used in separating muscles to expose the fractured bones. Once the fracture site is exposed, self- retaining retractors are needed to keep the soft tissues away from the site. The surgeon also needs to identify the superior and inferior borders of the fracture. Using the periosteal elevator, the periosteum is raised 2mm proximally and distally from the fracture site. The periosteal layer is stripped off just enough for the placement of plating. Since the periosteum covers most of the vascular and nerve supply in the diaphysis of the bone, too much stripping may compromise blood supply in its supported area. The operative area is also freed from debris and hematoma formation using a curette and consequently irrigated. Measurement and fitting of plates are the responsibility of the surgeon. However, the surgical assistant needs to assist the surgeon in these procedures. The surgeon may need to contour a compression or neutralization plate to fit the bone. The correct size plate is chosen and held in place over the fracture site on the bone. The length of the plate should be a least five times the diameter of the bone. The surgeon decides on the placement of interfragmentary screws and the specific points to drill holes through the opening of the plate and into the bone. The surgical assistant supports this critical procedure to ensure that the measured alignment is maintained and may be asked to drill the succeeding holes for the application of the plate. Besides, drilling holes requires stability and strength and therefore would require additional personnel for support. The first screw in each main fragment determines alignment. Locked screws are not placed through the plate until a satisfactory reduction is achieved in all planes. Lag screws may be used prior to locking screws in most situations when using a combination of both types of screws. Locking screws will not reduce fragments to the plate. The use of a whirlybird device (or one proximally and distally) is indicated to reduce the fracture and/or bone to the plate. Alignment may be improved by varying distance between implant and bone. The depth of drilling holes is specifically measured, usually at 3mm, but still largely depends on the thickness of the bone itself. The screws may have to be inserted in a semidiagonal fashion to prevent hitting the interfragmentary screw. The general rule is that to provide stability while not invoking unnecessary injury to the inner bone structures and function. Actually, the mechanism of plating technique varies largely on the extent of fractures and involvement of ligaments. A radiographic procedure or fluoroscopy may be needed to confirm the proper application of the plate and check the placement of screws. Lastly, the surgical assistant also helps ensure that no retractors, pins and other unwarranted objects are left in the operative site prior to closing. Wound Closure: Usually, the surgeon uses 20 undyed vicryl on CT2 needle to pull the fascia together in interrupted simple stitches. The surgical assistant may also be asked to close the skin with 30 prolene on a PS2 needle using the vertical mattress technique. The wound sites are cleaned and dressings are applied using xeroform, 4x4, webril and splint material with 4 and 6 inch aces. Patient is then transferred to the PACU with the vital signs and neurovascular checks ordered as a routine procedure. Unusual postoperative bleeding, apart from the normally associated in every surgery, is reported as this may compromise vascular and nerve integrity in the operated leg. Bibliography Current Surgical Diagnosis and Treatment 12th ed. Gerard M. Doherty Pages1144-1149 Copyright 2006 by McGraw- Hill Companies Skeletal Trauma Basic Science, Management, and Reconstruction Bruce D. Browner, Alan M. Levine, Jesse B. Jupiter, Peter G. Trafton, Christian Krettek - 2009 Pages 2324 Copyright 2009, Elsevier Science (USA) Surgical treatment of orthopaedic trauma James P. Stannard,Andrew H. Schmidt,Philip J. Kregor Pages 72- 76 Copyright 2007, Thieme Medical Publishing Relevant surgical exposures Bernard F. Morrey, Matthew C. Morrey Pages 215- 232 Copyright 2008, Lippincott Williams and Wilkins Rockwood and Green's Fractures in Adults Robert W Bucholz, Charles Court-Brown, James D. Heckman Pages 1931- 1999 Copyright 2009, Lippincott Williams and Wilkins Read More