Episode 1: Occult Fractures & Dislocations February, 2010

Transcription

1 Episde 1: Occult Fractures & Dislcatins February, 2010 Prepared by Lucas Chartier Mderated by Dr. Antn Helman Expert Guests: Dr. Arun Sayal & Dr. Nathalie Mamen Case 1: Occult hip fracture 67y.. wman with severe COPD n lng-term sterids wh fell frm standing height Ambulating well at current time, but with grin pain Findings suspicius f hip fracture: Triad f 1.new inability t weight bear, 2.hip pain n axial lading f leg, and 3.inability t straight leg raise are highly specific fr hip fracture Grin pain Percussin test: Percuss patella bilaterally while listening with stethscpe n symphysis pubis. Unilateral diminished sund (due t effusin) shuld increase suspicin. Dn t frget hip injury can present as knee pain, especially in children and elderly Pelvic ring and femral neck fractures are mutually exclusive: In a study with >100 elderly patients unable t weight bear after a fall, n patient with a fracture f the femral neck had an assciated fracture f the pelvic ring r vice versa fund n MRI. Lakshmanan et al. J Bne Jint Surg Br, Vl 89-B, Issue 10,

2 Imaging chices in ccult hip fracture: CT scan: in general, very gd at identifying fractures invlving bne crtex. Mst studies cmpare 4-slice CT vs MRI and shw that MRI is far superir fr identifying ccult hip fractures. Hwever, newer-generatin CT scans (64-slice) may be as sensitive and specific fr hip fractures cmpared t MRI, especially when 3D recnstructins are available (n studies t cnfirm this yet). MRI: The gld standard. Allws better lk at bne marrw (trabecular bne), but might vercall certain injuries that are nt clinically relevant. Bne scan: Very sensitive at 48-72hrs (24hrs fr newer 3-phase array scans) but nt specific and pr lcalizatin, and ptential fr cmplicatins while patient is bedridden waiting fr scan (VTE, pneumnia, pressure ulcers, delays t surgery). Ultrasund: May demnstrate effusin in ccult hip fracture A study frm Israel had 100% sensitivity fr identifying pst-traumatic hip fracture, but nt ready fr prime time Safran et al. J Ultrasund Med 2009; 28: A prpsed algrithm fr suspected ccult hip fracture: In yung patients with high-energy trauma, a fracture in the crtex will likely be seen If x-rays are negative but clinical suspicin is high, mve n t CT scan In elderly with lw-energy trauma, ccult fractures are less likely t invlve crtex If x-rays are negative but clinical suspicin is high, mve n t MRI (preferred) r 64-slice CT if MRI nt available

3 Case 2: Snwbarder s fracture 18y.. wman landed funny while snwbarding and had immediate left ankle pain Very swllen inferir and anterir t the tip f fibula, with tenderness ver the anterir talfibular ligament (ATFL) Ankle sprain mimics: 1. Snwbarder s fracture (lateral prcess f talus), 2. Psterir talus prcess fracture, 3. Achilles tendn rupture, 4. Anterir prcess calcaneus fracture, 5.Talar dme fracture In snwbarder s fracture the feet are fixed in drsiflexin, and the anterir ft usually everts as the snwbarder lands (very different mechanism than classic inversin ankle sprain). The fibula impacts the lateral prcess f the talus causing a fracture. Brden s view (Mrtise view) x-ray: Ft in plantar flexin; lateral aspect f the talus better visualized The plantar talus shuld shw a symmetric V in nrmal x-ray An asymmetric V sign indicates a displaced fracture requiring surgery When in dubt, place a psterir slab and make the patient nn weight-bearing until fllw-up Case 3: Knee dislcatin 40y.. male in belted MVC (frntal cllisin at 80km/h) Severe knee pain and tenderness and limited ROM, but n defrmity 50% self-reduce befre presenting t the ED, and with distracting injuries can be easily verlked

4 Cmmn mechanisms: pedestrian-vs-car, cntact sprts injuries and knee-tdashbard mechanism 1/3 rd will have neurvascular injuries, with significant mrbidity Knee-t-dashbard DDx: Psterir hip dislcatin, tibial plateau fracture, patellar fracture, knee dislcatin, psterir acetabular fracture Physical exam: Serial neurvascular exams: Distal pedal pulses +/- Dppler assessment if decreased sensatin in perneal nerve distributin, assume cncmitant ppliteal artery injury Findings suspicius fr ccult knee dislcatin: 3 ut f 4 knee ligament laxity (ACL, PCL, MCL, LCL) Adjuncts: Ankle-Brachial Index (ABI): >90% is reassuring, and can be mnitred serially CT-angigram if suspicius f vascular damage, and cnsult vascular Cmplicatins: In patients with knee dislcatin assciated with vascular injury, 15% will develp ischemia when repair is delayed by >8hrs Case 4: Scaphid fracture 10y.. by with FOOSH and lne snuff bx tenderness Epidemilgy: Less likely in children <15y.., adults >50y.., 15% f fractures will be ccult n initial x-rays

5 Physical exam - 3 key maneuvers: 1. Palpatin f snuff bx with wrist ulnarly deviated, 2. axial lading f thumb with pain in the anatmical snuffbx and 3. palpatin f vlar aspect f scaphid with wrist radially deviated 3 f 3 gives 90% risk f scaphid fracture (70% with 2 f 3) X-ray imaging: Order specific scaphid views Cnsider clenched fist view t splay carpals, especially if tenderness is mre at the lunate bne Might reveal a dynamic Terry Thmas sign (r David Letterman sign) if >3mm between scaphid and lunate cnsistent with a scaph-lunate ligament tear In negative x-ray with high clinical suspicin: Immbilizatin with thumb spica splint is mst cmmnly used precise psitin f immbilizatin des nt effect utcme Other ptins: CT in ED, Bne Scan at 72hrs, MRI must weigh time ff wrk/sprt if immbilize vs expense and radiatin expsure f early advanced imaging Fllw-up: Lnger fllw-up (10-14d) necessitates lnger immbilizatin perid, but allws fr mre time fr the fracture t reveal itself cmpared t shrter perid (7d) many scaphid fractures take up t 16 weeks t heal Case 5: Psterir shulder dislcatin 56y.. male fund dwn by wife, fund t have glucse f 1 by EMS Hlding bilateral shulders in internal rtatin, and there is resistance t external rtatin attempts

6 2-3% f shulder dislcatins, 15% bilateral and ften missed n first visit (50-80%!) Assciated with 3 Es: epilepsy, ethanl and electricity Mechanism: axial frce with shulder internally rtated and abducted Clinical findings: Prminent cracid, and humeral head psterirly displaced (vs. squared shulder f anterir dislcatin) Patients hld arm internally rtated, and reversed Hill-Sachs lesin (engagement f humeral head n psterir glenid rim) ften prevents external rtatin Diagnsis: Axillary view n x-ray very useful, as well as the subtle light bulb sign n AP (lss f asymmetry f the humeral head created by greater tubersity due t the internal rtatin f the humerus) Reductin: 1. Physician s cntralateral hand puts anterir pressure n the patient s psterir humeral head (eg, left hand n right shulder) 2. Physician applies gentle lngitudinal dwnward tractin f patient s arm 3. Assistant externally rtates patient s arm Immbilizatin: Arm hanging in neutral psitin, with internal r external rtatin (recent studies shw external rtatin may be better, but impractical) Length in weeks: 8 minus decade f life, t max f 3, maybe even shrter Case 6: Calcaneus fracture 29y.. male jumped frm height while under the influence f crack ccaine Tender t palpatin L-spine and entire bilateral extremities, ankles and feet swllen, psitive pulses X-rays all nrmal lwer extremities, but multiple L-spine cmpressin fractures Fall frm height nt feet: Lk fr assciated injuries: spinal injuries (esp. L-spine), cntralateral calcaneal fracture, and ankle fractures Calcaneal injuries have high mrbidity with 20% f patients debilitated at 3yrs Calcaneal fracture imaging: Bhler s angle n lateral view x-ray f ft measured between the line frmed by psterir tubersity f calcaneus apex t anterir prcess, and line frmed by apex t anterir prcess (see image) Nrmal is 20-40, <20 suggestive f cmpressin fracture f calcaneus

7 Harris view (axial view f calcaneus) Management: Usually needs CT scan t determine whether fracture is extra-articular (cnservative management) r intra-articular (perative management) Any displacement typically requires perative repair