Podcast 722: Lower Extremity Dislocations

Emergency Medical Minute

Contributor: Donald Stader, MD

Educational Pearls:

• Hip Dislocation
• • Prolonged dislocations can impair blood supply to femoral head
  • Hip dislocation for >6 hours puts patient at high risk for needing a hip replacement in the next two year
• Knee Dislocation
• • High mechanism
  • Often looks anatomically normal on knee x-ray
  • Vascular injuries of the popliteal artery can cause significant morbidity with some studies suggesting an 80% amputation rate if not treated within 6 hours
• Ankle Dislocation
• • Common dislocation and often co-occurs with ankle fractures (bimalleolar/trimalleolar)
  • Pressure on the skin from the displaced joint can cause skin tenting, which can lead to skin necrosis
  • Hematoma blocks work well for ankle reductions as an adjunct to or substitute for procedural sedation

References

Arnold C, Fayos Z, Bruner D, Arnold D. Managing dislocations of the hip, knee, and ankle in the emergency department. Emerg Med Pract. 2017;19(12):1-28.

Dawson-Amoah K, Raszewski J, Duplantier N, Waddell BS. Dislocation of the Hip: A Review of Types, Causes, and Treatment. Ochsner J. 2018;18(3):242-252. doi:10.31486/toj.17.0079

Patterson BM, Agel J, Swiontkowski MF, Mackenzie EJ, Bosse MJ; LEAP Study Group. Knee dislocations with vascular injury: outcomes in the Lower Extremity Assessment Project (LEAP) Study. J Trauma. 2007;63(4):855-858. doi:10.1097/TA.0b013e31806915a7

Ross A, Catanzariti AR, Mendicino RW. The hematoma block: a simple, effective technique for closed reduction of ankle fracture dislocations. J Foot Ankle Surg. 2011;50(4):507-509. doi:10.1053/j.jfas.2011.04.037

Summarized by John Spartz, MS4 | Edited by Erik Verzemnieks, MD