Patella dislocation: Difference between revisions
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*Chronic: women/teenage girls<ref name="epi"></ref> | *Chronic: women/teenage girls<ref name="epi"></ref> | ||
*Commonly lateral displacement and unable to extend knee | *Commonly lateral displacement and unable to extend knee | ||
==Clinical Features== | ==Clinical Features== | ||
[[File:Patellar dislocation.jpg|thumb|patella dislocates laterally]] | |||
*Patella is usually displaced laterally; knee is held in flexion | *Patella is usually displaced laterally; knee is held in flexion | ||
*Acute: often with large hemarthrosis | *Acute: often with large hemarthrosis | ||
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==Evaluation== | ==Evaluation== | ||
[[File:Patellaluxation ap 001.png|thumb]] | |||
*Xray if traumatic mechanism to rule out fracture | *Xray if traumatic mechanism to rule out fracture | ||
*Do not need xay prior to reduction if chronic | *Do not need xay prior to reduction if chronic | ||
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==Management== | ==Management== | ||
[[File:Patellar Dislocation Relocation.jpg|thumb|Relocation with lateral pressure on dislocated patella]] | |||
*Reduce; do not need x-rays prior to reduction | *Reduce; do not need x-rays prior to reduction | ||
**Mild flexion of hip (20-30 degrees) to relax quadriceps | **Mild flexion of hip (20-30 degrees) to relax quadriceps | ||
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*Unable to reduce or loose bodies/fracture on post-reduction imaging | *Unable to reduce or loose bodies/fracture on post-reduction imaging | ||
**Obtain immediate ortho consult | **Obtain immediate ortho consult | ||
==Disposition== | |||
==References== | ==References== | ||
Revision as of 21:43, 28 April 2017
Background
- Occurs with trauma to an extended knee with externally rotated foot and twisting motion[1]
- Acute: in traumatic injury, occurs equally in men/women [2]
- Chronic: women/teenage girls[2]
- Commonly lateral displacement and unable to extend knee
Clinical Features
- Patella is usually displaced laterally; knee is held in flexion
- Acute: often with large hemarthrosis
- Chronic: little to no swelling
Differential Diagnosis
Knee diagnoses
Acute knee injury
- Knee dislocation
- Knee fractures
- Meniscus and ligament knee injuries
- Patella dislocation
- Patellar tendonitis
- Patellar tendon rupture
- Quadriceps tendon rupture
Nontraumatic/Subacute
- Arthritis
- Gout and Pseudogout
- Osgood-Schlatter disease
- Patellofemoral syndrome (Runner's Knee)
- Patellar tendonitis (Jumper's knee)
- Pes anserine bursitis
- Popliteal cyst (Bakers cyst)
- Prepatellar bursitis (nonseptic)
- Septic bursitis
- Septic joint
- DVT
Evaluation
- Xray if traumatic mechanism to rule out fracture
- Do not need xay prior to reduction if chronic
- Post-reduction x-ray: confirm reduction, eval for fractures and loose bodies (avulsions, misalignment, etc)[3]
- Common associated fractures
- Medial patella facet
- Lateral femoral condyle
Management
- Reduce; do not need x-rays prior to reduction
- Mild flexion of hip (20-30 degrees) to relax quadriceps
- Extend and slightly hyperextend the knee and slide patella back into place
- Knee immobilizer, NSAIDs, partial weight-bearing
- Orthopedic follow-up within 1-2wks
- Unable to reduce or loose bodies/fracture on post-reduction imaging
- Obtain immediate ortho consult
Disposition
References
- ↑ Review of Orthopaedics, 6th Edition, Mark D. Miller MD, Stephen R. Thompson MBBS MEd FRCSC, Jennifer Hart MPAS PA-C ATC, an imprint of Elsevier, Philadelphia, Copyright 2012
- ↑ 2.0 2.1 Fithian DC, Paxton EW, Stone ML, Silva P, Davis DK, Elias DA, White LM. Epidemiology and natural history of acute patellar dislocation. AJSM 2004;32:1114-1121
- ↑ Krause E A. et al. Pediatric lateral patellar dislocation: is there a role for plain radiography in the emergency department? J Emerg Med. 2013 Jun;44(6):1126-31