Knee Dislocations and management options

Knee dislocations

1. Knee Dislocations

2.  C omplete congruency loss between the distal femoral and proximal tibial articular surfaces Serious and potentially limb threatening injury Surgical emergency

3. Problems 50% reduced by the time of review Lack of swelling d/t capsular tear Involves atleast 2 ligaments Risk of Nerve and Vessel injury Pulse can still be present d/t collateral supply even if injured Compare both sides/ ABI Delayed thrombosis in case of intimal injuries Serial examinations Risk of amputation if delay of >8 hours in 85%

4. 0.02% of orthopaedics injury More common in Men

5. Mechanism of Injury High energy Injuries: MVA Low energy Injuries: Athletes and fall from height 5-10feet Ultra low energy: Morbid obese (BMI>45)

6. Schenck Classification

7. Kennedy Classification 30-50% 30-40% 13% 3%

8. Complications Arthrofibrosis  or stiffness- m/c complication 38 %  MUA/ Arthroscopic adhesiolysis Instability: 37% Redislocations uncommon Compartment syndrome Deep venous thrombosis Fractures Periarticular soft tissue injuries Meniscus 55% articular cartilage 48 % patellar tendon rupture

9. Peroneal nerve injuries : 10 % to 40% of patients partial recovery in up to 50% Risk-   Male, patients with obesity, and associated fibular Management- ankle-foot-orthosis (AFO) to prevent equinus contracture . Acute - neurolysis or exploration of the nerve at the time of the reconstruction. Chronic- nerve repair,or tendon transfer. Tibial nerve injury is rare.

10. Vascular injuries- 5% to 15% of all knee dislocations KDIV dislocations highest rate of vascular injuries.  tethering at the popliteal fossa proximal - fibrous tunnel at the adductor magnus hiatus distal - fibrous tunnel at soleus muscle geniculate arteries may provide collateral flow and palpable pulses masking a limb-threatening vascular injury managed with emergent vascular repair and prophylactic fasciotomies 20% Amputation

11. Management ATLS Pre and post reduction NV examination and documentation Serial Examination Pulse- DP/TP ABI Distal pulses absent- surgical exploration with or without imaging is recommended. If distal pulses present and ABI score >0.9, 48 -hour observation with serial examinations. distal pulses present with an ABI score <0.9 need to be emergently evaluated with subsequent imaging studies Duplex vs CT angio Vs MRA

12. Emergency reduction and post reduction splinting- Ex Fix vs bracing Irreducible dislocations, open reduction via Anteromedial approach Surgical vs conservative management Operative management has reported higher rates of return to work and return to sport  Conservative management more stiffness Staged/delayed vs Acute Recon Acute reconstruction/repair is typically defined as surgery within three weeks of injury Better knee function with acute and staged surgery over delayed Arthroscopic vs open procedures Repair vs Reconstruction of ligaments

13. Take home message Involve the surgeons from the beginning if concerns of vascular injury EUA for all fractures around knee Check Pulse for every injury around knee

14. References Campbell’s Operative Orthopaedics Rockwood & Green’s Fracture in Adults Orthobullets.com Knee dislocations- Current concepts Evidence based approach to Multi Ligament injuries

15. Thank you