ACUTE FRACTURES OF THE FIFTH METATARSAL

history
. Three distinctly different patterns
. Avulsion fracture of styloid process
. Transverse fracture of proximal diaphysis (Jones fracture)
. Distal spiral fractures (Ballet fracture)
. Avulsion fractures occur by inversion mechanism.
. Jones fracture common in running, jumping sports
. May report prodrome of pain prior to presentation with Jones fracture,
suggesting stress reaction in bone
. Lateral foot pain with weight-bearing
physical exam
. Tenderness over base of fifthmetatarsal
. Pain with active eversion of foot
. May have pain with passive inversion
. Be sure to examine lateral ankle ligament stability.
studies
. Plain radiographs (AP, lateral, oblique)
. Avulsion type is usually extra-articular
. Three patterns Jones fracture: acute, delayed union, nonunion
. True acute Jones fracture will have sharp fracture line, no intramedullary
sclerosis.
. Delayed union: see some evidence of pre-existing fracture (wider
fracture gap, some intramedullary sclerosis)
. Don’t confuse avulsion type with two sesamoids: os peroneum (in
peroneus logus) and os vesalianum (in peroneus brevis).
. Don’t confuse avulsion type with unfused apophysis at base of fifth
metatarsal (closes age 16).
differential diagnosis
. Stress fracture
. Lateral ankle ligament injury
. Injury to cuboid-metatarsal joint
. Peroneus brevis tendinitis/tenosynovitis
treatment
. Avulsion fracture of styloid process
. Short-leg walking cast 2–3 weeks
. Weight-bear as tolerated
. Even nonunion of this type of fracture can be left alone.
. Symptomatic nonunion (rare): excise fragment, repair peroneus
brevis
. Displaced intra-articular avulsion fracture (rare): consider open
reduction/internal fixation
. Jones fracture
. Acute: nonweight-bearing cast immobilization 6–8 weeks
. Consider surgical treatment in athlete

. Delayed union: consider trial of nonweight-bearing cast, immobilization,
may require surgery
. Nonunion: surgery
. Medullary curettage and inlay bone graft or closed intramedullary
screw fixation with 4.5-mm malleolar screw
. Use largest screw diameter possible.
. Postop: nonweight-bearing cast for 2 weeks, followed by progressive
weight-bearing in hard-soled shoe
. Ballet fracture
. Short-leg walking cast or Camwalker
disposition
N/A
prognosis
. Acute fractures heal in 6–8 weeks.
. Delayed union treated conservatively may take>1 year for full healing.
. Nonunion treated with surgery heals in average 3months.
. Return to sports after surgery: approximately 8 weeks
. Complications of screw fixation
. Screw fracture
. Screw protrusion out of metatarsal
. Tenderness over screw head
. Refracture
caveats and pearls
. These fractures have propensity for nonunion due to poor blood
supply.
. Refracture can occur if return to sports too early.
. Use of foot orthosis recommended for early return to sports
. Plain radiographs may not be sensitive enough to determine healing
. Consider CT or tomograms.
. If refracture occurs after return to sports, consider exchange to
larger screw or use of inlay bone graft.

SOUND MIXING

The final sound mix, called the rerecording mix, combines and balances separate dialogue, sound effects and music tracks into one final soundtrack.The rerecording mixer sets the level of each sound element to highlight the most important sounds. Generally, the mixer emphasizes dialogue and key sound effects while softening background noises like car engines or street sounds, unless the story demands that dialogue be difficult to hear, as in a battle scene. Contrast between sound and image or between sound and silence is effective to build tension or to deliver more information.The final shootout in Road to Perdition takes place in a downpour. Instead of the expected pounding deluge on the soundtrack, we hear only the whisper of gentle rain, a subtle cue that this is a scene envisioned many years later by the killer’s son. Loud sound effects are more jarring if they are followed or preceded by soft sounds or by silence. Because the film viewer cannot hear everything that is seen on the screen, sound mixers must direct the viewer’s attention to the important elements. One way to do this is by using sound as it might be heard by a character in the film. This is called “point of audition.” At one point in the D-Day invasion scene in Saving Private Ryan, the sound-track is muffled because we are hearing sound from the perspective of a character temporarily deafened by the bombing. Just like a movie camera, sound can move the viewer from a “long-shot” to a “close-up.” By fading noisy background chatter in a crowded room, a filmmaker can direct the audience’s attention to an intimate conversation between two people. Movie sound is usually associated with the people and objects onscreen. When the film shows a woman walking a dog down a busy street, the audience hears her voice, the jingle of the dog’s leash, and the roar of the passing cars.This is called “source sound.” Narration, voiceovers and musical scores are the most common examples of non-source sound. Other offscreen sounds can alert the viewer to a change in scene, mood or character. In The Last Samurai, for instance, the audience hears the almost supernatural sounds of the advancing samurai troops for some time before they emerge from the mist. Overlapping sound can connect unrelated settings, places or times. At the beginning of Apocalypse Now, the synthesized sound of helicopter blades is merged with that of a ceiling fan, taking the story from the main character’s memories of fighting in the Vietnamese jungle to his present location in a Saigon hotel. Sound differs depending on a scene’s mood, location, historical period and time of day. It can be used to enhance characterizations.When Michael Corleone kills his dinner companions in The Godfather, a train outside thunders past like an unuttered scream, mirroring his disturbed emotional state. The soundtrack, as much as the visual effects, help the animated characters in Stuart Little hold their own with the live actors. Modern 35mm film stock carries four sound tracks: Dolby stereo, an analog system, Dolby SR-D digital, SDDS (Sony Dynamic Digital Sound) and DTS (Digital Theater Systems). By using this combined format, one film print can be screened in any theater, no matter what sound system is in use. Have your students think about the following scene:A boy and girl walk down a quiet road. Turning a corner, they see a menacing bulldog behind a sagging chain link fence. The angry dog lunges against its restraints, banging into the fence. The children give the dog a wide berth, but the boy slips in a puddle of water.The girl pulls him up by his hands, and they run quickly to safety.

TREATMENTS FOR ANTERIOR CRUCIATE LIGAMENT INJURY

Treatment
. Acute
. Establish diagnosis
. Ice, resolution of swelling, closed-chain quadmotion recovery
. Avoid immobilization
. Physical therapy
. Consider MRI
. Treatment considerations
. Age
. Activity level
. Category I sports (e.g., basketball, football, soccer, volleyball)
. Associated injuries (e.g., meniscus,MCL)
. Amount of pathologic laxity (e.g., Grade 2 or 3 pivot)
. Sports participation
. Expectation
. KT-1000 maximummanual (>6mmSSD, poor prognosis)
. Treatment options
. Nonsurgical
. Activity modificationmandatory
. ACL brace – Low-level activities
. Does not prevent instability
. Reduces severity and frequency of instability
. May require arthroscopy for meniscal pathology
. Surgical: tissue options
. Patellar tendon autograft
. Hamstrings
. Quadriceps tendon
. Allograft
. Irradiated vs. nonirradiated
. Patellar tendon vs. Achilles tendon
Disposition
N/A
Prognosis
. Nonsurgical treatment
. Low probability of high-level sports participation
. High likelihood of recurrent injuries –meniscal, articular
. Subjective satisfaction generally low
. 50% function due to ACL functional brace
. Surgical treatment
. Preferred for most individuals
. Stability success 85–90%
. Patient satisfaction 95%
. Patellar pain testing variable (10–40%)
. Side-to-side functional testing: 40–90% normal
. Return to play
. Nonoperative
. Should be braced
. Usually 4–6 weeks
. Caution that reinjury common
. Reconstructive
. Graft and sport dependent
. 4–6monthsmost surgeons; others recommend 6–9months
. Criteria – Normal stability, motion functional testing within
10–15%
. Complications of surgical treatment
. Infection (1%)
. Deep venous thrombosis, pulmonary embolus (1%)
. Patellar fracture, patellar tendon rupture (1%)
. Loss ofmotor (extension and/or flexion)
. Recurrent laxity (micro/macrotraumatic)
. Reinjury (5–10%) – Time-dependent
. Opposite side ACL injury –More common than graft disruption
Caveats and Pearls
. Suspect ACL injury in athlete with hemarthrosis.
. A patient with a displaced bucket handle meniscal tear (locked
knee) has an ACL injury until proven otherwise.
. “Partial” ACL injuries are extremely uncommon (<5%); athlete has
an ACL-deficient knee until proven otherwise.
. ACL diagnosis is established by history and exam; MRI should not
be used to establish diagnosis.
. ACL reconstructive surgery is not a surgical emergency.
. Postop motion complications reduced with delayed surgical treatment
. Beware of associated MCL injury, which may contribute to delayed
motion recovery.
. Medial meniscal tears more common in chronic ACL knees; lateral
meniscal tearsmore common in acute injuries
. Postoperative ACL bracing controversial
. ACL injuries three to four times more common in females (multifactorial)
. Accelerated rehab programs for patellar tendon graft current standard
. Surgical results similar for patellar tendon vs. hamstring autograft
. Surgical results of single- vs. double-incision arthroscopic techniques
similar
. Current graft choices: patellar tendon autograft, hamstring, quadriceps
tendon, nonirradiated patellar tendon allograft
. Outpatient ACL reconstruction feasible
. Postop continuous passive motion is longer standard of care
. Avoid open-chain quad extension exercises during rehab.

ACUTE NAVICULAR FRACTURE

History
. History of trauma
. Midfoot pain and swelling
Physical exam
. Swelling and exquisite pain on dorsomedial aspect of midfoot
. Dorsal lip avulsion – two ligaments insert on dorsum of navicular
. Dorsal talonavicular
. Stressed with inversion and plantarflexion
. Anterior aspect of deltoid ligament
. Stressed with eversion
. Tuberosity fractures
. Result of acute valgus or eversion injury increases stress on posterior
tibialis tendon
Studies
. AP, oblique, and lateral radiographs
. Examine closely formidtarsal joint (Lisfranc) injuries
. Bone scans, CT scan, MRI for occult fractures
. Differentiate acute tuberosity fracture fromaccessory navicular
. Accessory navicular is smooth and regular
Differential diagnosis
. Cuneiformand cuboid fractures
. Navicular stress fracture
. Running or jumping athletes
. Navicular avulsion fracture
Treatment
. Dorsal lip avulsion
. Conservative
. Weight-bearing cast for 4–6 weeks
. Open reduction and internal fixation if fragment is>25% of navicular
. Displaced acute fractures treated with anatomic and stable internal
fixation
. Anatomic reduction of talonavicular joint more critical
. Mobility of this joint is important for function
. Anatomic reduction of anterior and distal navicular not critical
. Naviculocuneiformjoints have littlemotion
Disposition
N/A
Prognosis
. Navicular is largely covered with articular cartilage
. Notmuch room for nutrient vessels to enter
. Makes the tarsal navicular subject to osteonecrosis
Caveats and Pearls
. Located in the uppermost part of the arch, the navicular is the keystone
for vertical stress on the arch
. Anatomic reduction essential to restore talonavicular motion

LEARNING from the BEST – PART A

Using Computer Generated Imagery (CGI), an animator can reproduce the three-dimensional effects of stop-motion photography or the twodimensional effects of hand-drawn animation. Instead of pen and ink, paint, clay, paper or cels, computer animators use a screen, a mouse, hardware and software and mathematical formulas. Rather than sketching out characters and objects like traditional animators, computer animators build a three-dimensional "model" that can be viewed from different angles.This model can be displayed as a "wireframe," which looks like wires, in "polys" mode, similar to video game graphics, or "anim rendered," a more polished representation. CGI can imitate camera moves and angles that would be difficult or impossible to achieve with traditional cel animation: the swoop from the chandelier to the dancing couple in the ballroom scene of Beauty and the Beast, for example. Because of its ability to mimic reality, CGI is also used to produce special effects in live action films. CGI can create digital tears or blood, embellish backgrounds and sets, make a small crowd seem large, or touch up the actors' wrinkles and flaws. The 1982 film Tron, which combined live-action with animation, was the first film to use CGI on a large scale. Early computer graphics looked unappealingly flat, but recent improvements in technology such as "bump maps" create more realistic surfaces.When the Academy instituted the Best Animated Feature Film award in 2001, it was captured by the CGI-animated film Shrek. Computer animators still have trouble duplicating soft shapes and textures such as human skin and hair and the movement of clothes and draperies.The most difficult task facing the special effects animators who created Gollum for the live-action film The Lord of the Rings: The Two Towers was developing new computer codes to provide the creature with translucent, lifelike skin. Use of the computer does not necessarily mean less work for the animator. It took four years to complete Toy Story, the first completely CGI-animated feature; coincidentally, it took the same amount of time for the Disney studio to finish Snow White and the Seven Dwarfs. CGI may never completely replace traditional animation, because some animators still prefer the latter’s personal touch and slight irregularities. For others, using CGI can be compared to using the computer instead of a typewriter for writing, in that the new tool allows the animator to manipulate ideas and images with greater freedom. Part A. Have your students compare hand-drawn or stop-motion animation to CGI animation, using selections from these films: Snow White and the Seven Dwarfs, Alice in Wonderland, Lilo & Stitch and Fantasia employ hand-drawn cell animation. Chicken Run and The Nightmare before Christmas are three-dimensional films made using stop-motion photography. Toy Story and Shrek are CGI animations. Most of Beauty and the Beast was drawn on cels, but the ballroom scene is a good example of early computer animation. CGI was used to create the stampede scene in The Lion King, an otherwise hand-drawn film. Ask your students if they notice differences between CGI and traditional animation. Have them consider why animators might choose a traditional method of animation if CGI animation can duplicate traditional effects.

ANTERIOR CRUCIATE LIGAMENT INJURY

History

. Mechanism: sudden deceleration, cutting, valgus force contact or
noncontact, hyperextension
. Patient may recall pop or tearing sensation – 80%
. Painful, inability to continue activity
. Rapid hemarthrosis within 3 hours – 80%
. If chronicmay have history of recurrent instability
. Common sports: skiing, basketball, volleyball, football, soccer
. May be isolated or in conjunction with multiple ligament injuries –
medial collateral (MCL), posterior cruciate (PCL), posterolateral or
knee dislocation
. Often associated with meniscal pathology and/or articular cartilage
injury
. Knee instability complaints: jumping, twisting, deceleration, cutting
activities
Physical exam
.Acute: effusion, bloody hemarthrosis if aspirated
. Joint line tenderness suggestive of associated meniscal pathology
. Ligament laxity exam – compare to uninjured knee
. Abnormal Lachman testmost sensitive test
. Increased anterior tibial translation @ 20–30. knee fusion
. Positive pivot shift test (Losee, Hughston, flexion rotator drawer
variants)
. Pathognomonic of complete anterior cruciate ligament (ACL) injury
. Subluxation – Reduction phenomenon related to axial compression,
valgus loading, and flexion/extension occurred at 15–30.
. Associated ligament laxity tests
. MCL – Valgus laxity at 0., 30.
. Lateral collateral ligament – Valgus laxity at 0., 30.
. PCL – Increased posterior translation at 90. (posterior drawer),
posterior sag test (gravity flexion test)
. Posterolateral – Increased posterolateral rotation, increased
external tibial rotation, asymmetric dial test
. Locked knee –Displaced bucket handle meniscal tear, rule out associated
ACL injury
Studies
. Radiographs
. AP, lateral, tunnel,Merchant (four views)
. Generally normal
. Lateral capsular sign (Segond fracture): marginal avulsion fracture
fromanterolateral tibial plateau pathognomonic
. Lateral notch sign (chronic ACL): accentuation of indentation
of sulcus terminalis in lateral femoral condyle; rarely seen with
PCL/posterolateral corner (PLC) injury
. Chronic ACL deficiency: periarticular osteophytes, tibial eminence
peaking, intercondylar notch narrowing
. MRI
. Highly sensitive/specific for ACL injury
. Generally does not differentiate between partial or complete
ACL injury
. Associated meniscal pathology common
. Bone bruise noted (80%), lateral femoral condyle, lateral tibial
condyle most common
. Effusion frequently noted
. MRI value: detecting associated meniscal pathology and articular
cartilage pathology
. KT-1000
. Instrumented laxity testing device
. Measures side-to-side differences (SSD) and absolute translation
. Dx: maximum manual SSD >3 mm; 30-pound anterior translation
>10mm
Differential diagnosis
. Hemarthrosis
. ACL, patellar dislocation, peripheral meniscal tear, intra-articular
fracture, PCL injury, popliteus tendon avulsion
. Instability
. Patellar instability
. Meniscal tear (e.g., bucket handle)
. Posterolateral
. Quad weakness – giving way with level walking/standing

ACUTE COMPARTMENT SYNDROME

history
. Definition: Increased pressure in a confined tissue space that
reduces capillary blood flow below a level necessary for viability of
normal tissue
. Etiology 1: Increased volume within a closed space (i.e., trauma,
hemorrhage, or reperfusion injury)
. Etiology 2: Decreased size of an enclosed space (i.e. cast, constrictive
dressing, orMAST trousers)
Pathogenesis
. Muscle injury: edema/hemorrhage – Increased pressure in enclosed
space – ischemia – further soft tissue damage
. Circulatory injury: Swelling with reperfusion – increased pressure in
enclosed space – ischemia – further soft tissue damage
. Muscle ischemia reversible up to 4 hours, irreversible after 8
. Nerve ischemia results in reversible neuropraxia under 3 hours and
irreversible after 8
Compartments
. Anterior
. Lateral
. Deep posterior
. Superficial posterior
physical exam
. Five P’s: Pain, Pallor, Paresthesias, Pulselessness, Paralysis
. Pain out of proportion to injury
. Pain with passive stretch of foot
. Pallor skin tone
. Loss of or decreased pulses (uncommon and/or a very late finding)
. Paralysis or sensory changes after ischemia >1 hour
. Tense, swollen compartments (most sensitive finding)
. Glossy appearance of skin
studies
. Labs
. Elevated CPK values are common with ischemia but also elevated
in trauma
. Compartment pressuremeasurement
. Indicated in polytrauma, obtunded patient, orwith inconclusive
clinical diagnosis
. Direct measurement of involved compartments using needle
catheter such as a Stryker STIC catheter, WICK catheter, or
transducer fromarterial line
. Pressure threshold requiring fasciotomy is controversial.
. Multiple sampling sites, with the highest value recorded and
used to determine the need for fasciotomy
. Fasciotomy recommended with a measured pressure >35
mmHg or a pressure 20 mmHg below the measured diastolic
blood pressure (number varies)
differential diagnosis
. Compartment syndrome is a surgical emergency. If clinically suspected,
then the diagnosis is compartment syndrome until proven
otherwise.
treatment
. Nonoperative
. Remove compressive dressings, casts, etc.
. Elevate leg to level of heart only.
. Compartment measurements if clinically suspicious
. Operative
. Two-incision fasciotomy to decompress compartments
. Anterolateral incision – half the distance between fibula and tibial
crest; used to decompress the anterior and lateral compartments
. Beware exiting superficial peroneal nerve through fascial defect
distally
. Posteriormedial incision – 2 cmposterior to medial tibia
. Delayed primary closure at 4–7 days with possible skin graft if
Needed

disposition
N/A
prognosis
. Good if recognized and treated early
. Poor if delayed diagnosis and/or intervention
Complications
. Infection
. Claw toes
. Dysfunctional extremity
. Amputation
caveats and pearls
. Early recognition is the key to successful treatment.
. Remember the five P’s.
. If you are thinking about checking the compartment pressures,
check them!
. Acute compartment syndrome is a surgical emergency.