Monday, August 26, 2019

Flexion Distraction Injury of the Lumbar Spine


Flexion Distraction Injury of the Lumbar Spine

It is sometimes called a seat belt injury or “chance fracture”. Usually, the patient is restrained, back seat passenger that is involved in a car accident and the person is wearing only a lap seat belt. The chance fracture is a variant of the flexion/distraction injury. The terminology is sometimes confusing, but a chance fracture could indicate a bony injury. It may present itself with a minimal compression fracture of the vertebral body, however, in this case all three columns of the spine are injured from distraction and tension. When you deal with a traumatic compression fracture in a young patient that is involved in a car accident, rule out a seat belt injury or “chance fracture”. This condition could be misdiagnosed or not diagnosed. Bowel trauma occurs in these cases due to crushing of the bowel between the lap seat belt and the spinal column, which results in devascularization and acute bowel rupture. In flexion/distraction injury, there will be an anterior wedge fracture of the vertebral body plus horizontal fracture of the posterior elements or distraction of the facet and the spinous processes. If it goes unrecognized, it may lead to progressive kyphosis with pain and deformity. This injury usually occurs in the thoracolumbar junction or in the midlumbar are. The posterior column fails first because of the axis of rotation is anterior to the vertebral body. The flexion/distraction injury is unstable in flexion and usually needs surgery to restore the disrupted tension band and prevent progressive deficit and pain, as well as enhance the functional recovery of the patient. In patients with flexion/distraction injury of the lumbar spine, up to 50% of these patients have associated potential life threatening injures such as visceral and gastrointestinal injury. Look for transabdominal ecchymosis; you will probably need to consult a general surgeon, and this condition occurs more in children. The hallmark of this injury is the axial split of the pedicle which is seen on the sagittal CT scan. There will be little comminution and since the center of rotation is the anterior longitudinal ligament, the posterior ligaments will be disrupted or the posterior neural arch is fractured transversely. Flexion/distraction injury or seat belt injury can be purely bony, purely ligamentous, or mixed. The treatment of flexion/distraction injury, especially if the injury is ligamentous, is usually a posterior reconstruction of the tension part of the spine with short segment fusion with instrumentation. Ligamentous injuries of the spine do not heal (needs to be fused). The bony chance fracture can be stable in extension and the fracture can heal. The fracture could heal, but the fracture will probably need long term follow-up. The fracture could be treated in a TLSO (Thoracic Lumbar Sacral Orthosis) brace and watch the fracture for the development of kyphosis.

Monday, August 19, 2019

Brown-Sequard Syndrome


Brown-Sequard Syndrome (BSS)

Brown-Sequard Syndrome results from an injury to one half of the spinal cord as seen in penetrating injuries. The spinothalamic tract fibers cross the midline below the level of the lesion resulting in contralateral loss of pain and temperature sensation. The posterior column and the corticospinal tracts carry vibration, position, light touch sensation, and motor function that are lost from the ipsilateral side of the body. The prognosis is usually good. 90% of the patients recover. If the patient has a wound on the right side, the patient will feel it on the left side. It is a hemisection lesion. There is loss of vibratory, light touch and motor on the same side while pain and temperature is lost on the other side.

Monday, August 12, 2019

Open Fractures of the Tibia


Open Fractures of the Tibia

25% of tibial shaft fractures can be open. Open fractures can lead to complications including wound problems, osteomyelitis, nonunions, and infected nonunions. The treatment of open fractures of the tibia can be challenging. A lot of the concepts are not black and white; they may be in the grey zone. We don’t know the best time for debridement. We don’t know what the optimal irrigation solution is and what the optimal pressure for the fluid is. We don’t know for sure the ideal duration of giving antibiotic prophylaxis, but we know that it is important to give the appropriate antibiotics early and do meticulous debridement. We know that the IM rod is better than the plate fixation or external fixator, and the result of the reamed IM rod or unreamed IM rod is the same. We need to close or cover the wound before 1 week and the vac can be used provisionally when we cannot close the wound, primarily at the optimal time. A grade I fracture is less than 1 cm. a grade II fracture is 1-10cm. A grade III fracture is more than 10 cm, and there is contamination. Grade III fractures are divided into three types. Grade IIIa fractures require adequate tissue for closure (or skin graft). Grade IIIb fractures require extensive periosteal stripping and the patient will need a flap (rotational or free flap). Grade IIIc fractures have a vascular injury that requires repair or amputation. The relative indication for amputation is warm ischemia for more than 6 hours, absent plantar sensation and severe ipsilateral foot trauma.
The most predictive factor for amputation is the severity of the soft tissue injury in the ipsilateral extremity. When comparing limb salvage versus amputation, the patient’s outcome is generally the same at 1-5 years. Lack of plantar sensation does not predict poor outcome after limb salvage. Segmental fractures are Grade III fractures, even if the open fracture is 1 cm. The ideal irrigation solution and the pressure used to controversial. Timing of the initial debridement is controversial. Irrigation and debridement within 6 hours was the gold standard in the past. Debridement is performed as a priority procedure no later than the morning after admission. There is no difference in infection rate for a patient who has the initial surgery before or after 6 hours, including patients with Type III open fractures. More than 40% of the patients usually wait longer than 6 hours for their initial surgery after arrival at the hospital. Delayed surgery for less severe fractures is acceptable as long as the debridement is done as a priority the following day. Unless there is a gross contamination, evidence is not clear as to when is the best time for the debridement. It seems like giving the patient antibiotics promptly is more important than the time of debridement. The preferred solution is normal saline and low pressure irrigation. Low pressure lavage may reduce reoperation rates due to infection, nonunions, and wound healing problems. Normally the tradition is to use 3, 6, and 9 liters of solution for Type I, Type II, and Type III open fractures (just recommendations). There is increased risk of wound healing with antibiotic solution. Meticulous irrigation and debridement of open fractures is important in decreasing the infection risk. Prophylaxis should be started as soon as possible. All patients with open fractures should receive first generation Cephalosporin’s that will cover gram-positive bacteria. You can give penicillin for farm injuries and clostridia prone wounds. You will give clindamycin if there is a penicillin allergy. In Type III open fractures, add aminoglycoside, such as gentamicin. It was found that local antibiotics delivery at the site of injury decreased the infection risk, such as cement beaded loaded with antibiotics. Antibiotic should be given within 3 hours of the time of injury (preferably given as soon as possible). There is reduction of 59% of acute infection in patients with open fractures treated with antibiotics. The infection rate is 1.6 times greater if antibiotics are given after 3 hours. Type I and Type II open fractures require antibiotic coverage for 24 hours after wound closure. For Type III open fractures, antibiotic administration should be given for a period of 72 hours after the injury and no more than 24 hours after wound closure. After the initial debridement, the patient will need staged debridement within 24-48 hours. There is a reduction infection rate, acute and chronic, for Type III open fractures with the use of systemic antibiotics and aminoglycoside cement beads compared with antibiotics alone. This combination of antibiotics lowers the infection rate for any open tibial fracture that is treated with an IM rod. Its affect is more noticed in Type III injuries. Plating of open fractures may cause chronic infection and infected nonunion. The healing time is doubled with plated open fractures. The IM rod resulted in a better alignment and lower reoperation rate than using external fixator. Also, no difference in the infection rate between the IM rod and the external fixator. You can use a reamed nail or an unreamed nail. They both have a comparable result and no difference in the outcome.
When reaming, you can use a bigger rod that provides better stability. Reamed nailing is superior in closed tibial fractures, but it is not superior in open tibial fractures. Reaming can cause increased pressure and disruption of the endosteal blood supply, can cause thermal necrosis and fat embolism with increased intramedullary risk of infection. The unreamed rod uses smaller nails and results in less stability but preserves the endosteal blood supply. Unreamed IM tibial rod appears to have a shorter time to union and fewer incidence of knee contractures when compared with circular wire external fixator. Nowadays, more and more orthopedic surgeons are using reamed nails for open fractures of the tibia. If you have a spiral fracture of the distal 1/3 of the tibia, you will need to get a CT scan of the ankle to identify a posterior malleolar fracture, which should be fixed before insertion of the IM rod. There is a lack of evidence to support the value of external fixator over the IM rod in open factures of the tibia. Due to patient discomfort, the high incidence of pin tract infection and loss of alignment, external fixator should not be used as a definitive fixation. Use external fixator temporarily (less than 4 weeks) and replace it with a rod in about 14 days. External fixator may be utilized for severely contaminated open fractures. Tibial fractures treated with a shorter duration of external fixator has reduction of the infection risk by 80%. When there is a shorter interval between removal of the external fixator and insertion of the IM rod of the tibia, there is a reduction of the risk of infection by 85%. In less severe soft tissue injuries, you do primary closure without tension. In cases of delayed closure, soft tissue coverage should be done within 7 days. Soft tissue coverage beyond 7 days will increase the infection. There is no difference in the incidence of infection in patients who had primary closure and delayed closure of the wound. It is recommended to do primary closure for Type I, Type II, and Type IIIa fractures with tension free closure and after timely antibiotic prophylaxis and adequate debridement. Intraoperative culture after debridement has no value. It does not predict future infection. In the upper 1/3 of the tibia, you can treat it by a medial gastrocnemius flap. In the middle 1/3 of the tibia, you can treat it by a soleus rotational flap. The use of a free flap for soft tissue coverage was less likely to have wound complications than the use of a rotational flap. The zone of injury may be larger than expected, and it may include the rotated muscle flap. The negative pressure wound therapy (the vac) is used frequently. The vac provides provisional coverage for wounds where the physician cannot do primary closure. There is decreased infection rate when using the vac. The vac is used for coverage after the initial debridement of the open fracture until the definitive coverage is done. It is a good temporizing dressing and can also be used in fasciotomy wounds. The vac promotes local wound healing. Bone morphogenetic protein (BMP2) decreases the need for secondary surgery and is used in acute open tibial fractures treated with IM rod.

Monday, August 5, 2019

Syndesmotic Injuries of the Ankle


Syndesmotic Injuries of the Ankle

The syndesmosis gives stability to the ankle. It resists external rotation and axial and lateral displacement of the talus. Syndesmotic injuries of the ankle can be challenging in the diagnosis and in the treatment. It may not be easy to obtain and maintain reduction of the syndesmosis. Approximately 50% of the patients with operatively treated supination/external rotation type fracture of the ankle have syndesmotic injury on stress radiographs intraoperatively. Anatomic reduction of the syndesmosis is crucial for a good clinical outcome. Restoration of the normal fibular length and alignment, as well as obtaining and maintaining the alignment of the syndesmosis significantly impacts the functional outcome of the patient. Malreductions of the tibiofibular syndesmosis is not uncommon, and it can occur in up to 30% of the patients. Fluoroscopy, direct visualization and reduction of the syndesmosis could improve the anatomic reduction. Syndesmotic injuries are common. They are found in sports injuries (high ankle sprain) or in ankle fractures such as supination/ external rotation Type IV, pronation/ external rotation and pronation/ abduction injuries. It does not occur with supination/adduction injury. In this injury, you will see vertical fracture of the medial malleolus and the talus will go medially. Syndesmotic fixation probably is needed more with an ankle fracture that has a high fibular fracture and deltoid ligament injury, than an ankle fracture that has fracture of the fibula with medial malleolus fracture. The higher the fracture in the fibula, the more incidence of syndesmotic disruption and the need for syndesmotic fixation. In fact, the high fibular fracture plus deltoid injury equals syndesmotic screw fixation (means syndesmotic screw fixation is needed more). To diagnose a syndesmotic injury, you will find an unstable mortise; it can be evident or occult.
You also need to suspect syndesmotic injury in proximal fibular fracture, which is called Maisonneuve fracture. Look at the disruption of the interosseous membrane and the syndesmosis. You do this by looking at the ankle and get an x-ray. You also suspect syndesmotic injury with sports injuries where there is a positive squeeze test (high ankle sprain). 20% of syndesmotic injuries of the ankle can be undetected on clinical examination. You should get stress-rays. You also suspect it in supination/external rotation Type II injury that has a fibular fracture. Provocative tests or the stress views are used in fibular fractures supination/external rotation Type II to see if it is really a Type II injury or if the injury is a Type IV and there is a hidden occult deltoid and syndesmotic injury. To do the provocative tests to diagnose an occult injury or syndesmotic injury of the ankle, do the gravity test or do the abduction/external rotation stress views or do weight bearing film. In weight bearing films, the dorsiflexion of the ankle can eliminate any errors on the medial side. Sometimes when the ankle is plantar flexed, the medial side looks widened, but it is not a true widening. Look for the tibiofibular clear space, look for the tibiofibular overlap, and look for the widened medial clear space (more than 5mm). The tibiofibular clear space will be greater than 5mm with syndesmotic injury. The tibiofibular clear space is probably the best radiologic measure because it is not affected by the position of the leg. If the syndesmosis is unstable, you need to fix it. It is the last part of ankle fracture fixation. You must have anatomic reduction of the syndesmosis. Before you fix the syndesmosis, you will need to evaluate the reduction of the syndesmosis. This can be done by direct inspection and reduction or by x-rays. You may need x-rays of the other side to assess accuracy of reduction of the syndesmosis intraoperatively. In surgery, you can test the stability of the syndesmosis. You can use the cotton test, use a bone hook, or pull on the fibula by levering it out by hemostat, by a freer or an elevator, or you can see the movement of the fibula. You can also do the abduction/external rotation test. You will do x-ray intraoperatively and check if the syndesmosis is stable or not and if it is reduced or not. So you want to restore the fibular length and see if the medial clear space and tibiofibular overlap are OK or not. Make sure that you do not have mortise instability, which is displacement of the talus out of the mortise. You want to restore the fibular length because this is key. The fibula must sit properly in the incisura. The morphology of the incisura is variable and that encourages malreduction. If the incisura is shallow, the fibula can be pushed anteriorly. If the incisura is deep, then the fibula can be pushed posteriorly, and this can cause malreductions and malrotation. Syndesmotic malreduction can occur from positioning of the reduction clamps. Anterior clamps can cause malreduction. Avoid translation of the fibula anteriorly when using anteriorly based clamps. Clamp placement in a neutral anatomical axis reduces syndesmotic malreduction. While oblique placed clamps results in syndesmotic malreduction, variation in the angulation of the reduction clamp and screw placement can cause iatrogenic syndesmotic malreduction and displaces the fibula in external rotation. Fixation of the fibula in as much as 30 degrees of external rotation may go undetected using intraoperative fluoroscopy. The malreduction may not be clinically significant if it is minimal; however, it can be very significant if the malreduction is significant. Screw fixation is supposed to be the gold standard for syndesmotic fixation; however, this is no longer the gold standard fixation method. You can fix the syndesmosis by screws, by suture buttons, and by a variety of different techniques. Patients with suture buttons return to work early and less frequently need their implant removed. The controversy is that there is no gold standard for the number of screws used, the number of cortices, the level of placement of the screws, the type of screws (3.5 or 4.5). I personally use 3.5 screws and rarely use 4.5 screws. I may also use cross screws in severe situations. I also use a plate in Maisonneuve fractures, not just screws over the fibula, the screws have to go through a plate to help the stability of the screws. You must have anatomic reduction of the fibula, as well as alignment. Achieving the fibular length can be a problem, especially if the fibula is comminuted. In this situation, you need to fix the medial malleolus first, then restore the fibular length.
The Dime Sign, the Shenton’s line, and the uninterrupted subcortical line. Syndesmotic screws are rigid, and they can break or loosen. The tight rope fixation avoids the problem of the rigid fixation, so it maintains the reduction while allowing physiological movement of the fibula (tight rope fixation has its own problems). I used to remove all syndesmotic screws, but now I don’t remove them unless it is necessary for pain or stiffness. I make the patient walk on it around 10-12 weeks. 17% of the screws will break, 13% become loosened, and ¼% of the screws are removed due to symptoms. The screws look bad on x-rays when they are broken or loosened, but these screws don’t cause a lot of trouble. If you keep the screws, it is just an x-ray problem and not a functional problem. If you leave the screws or if you remove the screws, there is no difference in functional outcome between screw removal and nonremoval. They found that when the syndesmosis is malreduced and then you remove the screws, then the patient feels better and the movement gets better. Retained, broken screws had a better functional outcome than the retained, intact screws. Fixation of the posterior malleolus adequately stabilizes the syndesmosis. If the fragment is minimally displaced, then the screws can be directed anteriorly to posteriorly. If the fragment is large, you can fix it with a buttress plate posteriorly. The posterior malleolar fixation restores the stiffness to 70% and the syndesmotic screw fixation restores the stiffness to 40% compared to intact specimens. There is a strong association between obesity and loss of syndesmotic reduction. Obese patients are 12 times more likely to lose syndesmotic reduction than nonobese patients. In regards to the syndesmotic injury, you will need to recognize it and fix it when the syndesmosis is unstable. Evaluate the reduction of the syndesmosis. Avoid malreduction. Remove syndesmotic screws only if needed.

Monday, July 29, 2019

Neonatal Compartment Syndrome


There are only a few cases of compartment in the neonate. This can be a difficult diagnosis. Compartment syndrome in the neonate does not present itself with the classic “P’s” as seen in adult patients. Compartment syndrome in the neonate does not present itself with the classic “P’s” as seen in adult patients. There are 5 P’s: pain/swelling, paresthesia, pulselessness, pallor, and paralysis. Diagnosis in neonate is usually made retrospectively after the patient has complications. The condition of compartment syndrome usually occurs within the first 24 hours of birth. It usually occurs in the forearm, is usually unilateral and occurs more in the dorsal aspect of the forearm. Risk factors are the mother may be diabetic, some hypercoagulable state (like polycythemia), and prematurity. The actual cause is not known, however it can be a combination of extrinsic compression and hypercoagulable state. Make sure to avoid missing the diagnosis of compartment syndrome. The infant will have a swollen, tense forearm associated with skin lesions on the forearm. The skin may have erythema, bullae, and edema. The skin lesions will be present at birth and usually at the forearm. The patient may also have pseudoparalysis, may lack spontaneous limb movement, and there might be some nerve injury involved also. The clinical diagnosis of compartment syndrome will be made after exclusion of other conditions such as infection, vascular injury, and amniotic band syndrome. The clinical diagnosis of compartment syndrome will be made after exclusion of other conditions such as infection, vascular injury, and amniotic band syndrome. Infection could be cellulitis or can be necrotizing fasciitis. Both should be excluded! Treatment of neonatal compartment syndrome of the forearm should be early diagnosis and immediate fasciotomy. Ischemic muscle contracture will develop from missing the diagnosis and delaying the treatment.

Monday, July 22, 2019

Anatomy of the Acetabulum


The column principle divides the acetabulum into an anterior and posterior column which becomes important when considering acetabular fractures and their management. The anterior column is composed of the anterior ilium, the anterior wall and dome of the acetabulum and the superior pubic ramus. The posterior column extends from the obturator foramen through the posterior aspect of the weight bearing dome of the acetabulum and then obliquely through the greater sciatic notch. The ischiopubic ramus is a complex structure that consists of the inferior pubic ramus and the inferior ramus of the ischium. It forms the inferior border of the obturator foramen. The pelvis is oriented to form an inverted “Y” shape. The obturator artery is a branch of the anterior division of the internal iliac artery. It arises in the pelvis and it enters the obturator canal. The obturator artery the divides into two branches: the anterior and posterior branches of the obturator artery form a vascular circle around the outer surface of the obturator membrane. An acetabular branch reaches the hip joint and joins the ligamentum teres to supply the head of the femur. It usually supplies a small portion of the head of the femur. Corona mortis is a connection between the internal iliac branch (obturator) and the external iliac or its branch, the inferior epigastric. Corona mortis is predominantly a venus connection and the arterial connection is much less. Its location on the superior pubic ramus is variable. It is about 3-7 cm from the symphysis pubis. It is located behind and on top of the superior pubic ramus and one must be careful with lateral dissection of the superior pubic ramus. The Corona Mortis is susceptible to injury in pelvic trauma and in pelvic surgery especially during the ilioinguinal approach.  Be aware that the sciatic nerve can be split, and this can be a normal variant. Keep the knee flexed and the hip extended during posterior approach to the acetabulum. This will protect the sciatic nerve. The sciatic nerve is posterior to the obturator internus muscle and anterior to the piriformis muscle. When using the sciatic nerve retractor in the lesser sciatic notch, the muscle and tendon of the obturator internus protects the sciatic nerve. It acts as a buffer layer between the retractor and the nerve, because the nerve is posterior to the muscle. Sliding trochanteric osteotomy allows exposure of the dome and the superior aspect of the acetabulum. This type of osteotomy keeps the muscles intact and this will balance its pulling forces. There will be less of a chance of displacement of the greater trochanter this way. The superior gluteal nerve is close to the superior gluteal artery at the greater sciatic notch. The superior gluteal nerve can be injured from approaches that involve more than 5 cm above the acetabulum. Excessive traction or attempt to control the bleeding from the superior gluteal artery at the greater sciatic notch, may injure the nerve by a suture or by a vascular clip that may entangle the nerve. Injury to this nerve may affect the gluteus minimus. Injury to this nerve affects the abductors of the hip joint and the patient may end up with Trendelenburg Gait. The inferior gluteal nerve may also be injured. It innervates the gluteus maximus muscle. The Lateral Femoral Cutaneous Nerve can become injured during the ilioinguinal approach for acetabular fixation. The Lateral Femoral Cutaneous Nerve usually passes under the ilioinguinal medial to the anterior superior iliac spine (ASIS).
Injury to the Corona mortis may lead to significant hemorrhage which may be difficult to control. The superior gluteal artery passes through the greater sciatic notch. Injury to the superior gluteal artery can be associated with acetabular fractures, especially fractures that involve the posterior column of the acetabulum. The superior gluteal artery cam ne damaged by aggressive retraction of the abductor muscles during posterior approach to the hip. The Medial Femoral Circumflex Artery (MFCA) can be damaged due to dislocation of the femoral head or from taking down the quadratus femoris from the femur instead of the ischium. You need to leave a tag of 1 cm for the piriformis and the obturator internus from the greater trochanter to preserve the deep branch of the medial circumflex artery. If you detach these two tendons too close to the trochanter, this could injure the deep branch of the medial femoral circumflex artery. The medial femoral circumflex is the main blood supply to the femoral head. The sciatic nerve is close to the acetabulum and can be injured. In fact, sciatic nerve injury is the most common traumatic and iatrogenic nerve injury connected to the acetabulum. Sciatic nerve injury can be approximately 10% with hip dislocation. The incidence may be higher with posterior acetabular fractures. When you examine a patient with an acetabular fracture, always check the sciatic nerve function. Check dorsiflexion of the ankle and the toes. It is peroneal division of the sciatic nerve that will be affected. Check for numbness on the top of the foot. Repeat the exam again just before surgery. Partial sciatic nerve injury can get worse from acetabular surgery. The sciatic nerve anatomy is variable but well described. There may be variations in its anatomy. These diagrams show the incidence of the most common patterns of the relationship between the sciatic nerve and the piriformis muscle.

Monday, July 15, 2019

Anatomy of the Adductor Longus Muscle


The adductor longus muscle is one of the adductor muscles of the hip located within the thigh. There are six adductor muscles for the hip and here is a diagram showing the arrangement of these adductor muscles. The adductor longus muscle arises from the anterior surface of the superior pubic ramus, just lateral to pubic symphysis. It is inserted into the middle third of the medial lip of the linea aspera on the posterior surface of the shaft of the femur. The adductor longus muscle is innervated by the obturator nerve which arises from the L2, L3, and L4 ventral rami of the lumbar plexus. Outside the obturator foramen in the proximal part of the thigh, the obturator nerve divides into anterior and posterior divisions. It is the anterior division of the obturator nerve which supplies the adductor longus muscle. The adductor longus muscle adducts and flexes the thigh, and helps to laterally rotate the hip joint. Adductor strains may occur in hockey players or soccer players. It is sometimes called a “pulled groin.” Adductor strains usually involve the adductor muscles, especially the adductor longus muscle. It occurs due to eccentric contraction of the muscle. The injury occurs due to external rotation of an abducted leg. The patient will have groining pain and pain at the site of the injury, usually near the pubic ramus. The patient will also have weak adduction. It may be difficult to differentiate an adductor strain from a sport hernia. X-rays are usually normal. MRI will show avulsion of the adductor muscles from the pubic ramus. Adductor strain treatment includes: ice, rest, protected weight bearing, and patient will go through a rehabilitation program. Surgery is rarely done and the role of surgery is not well defined.