Acute Joint Dislocation

1. Acute Joint Dislocation Dr. AbdulrahmanAlgarni, MD, SSC (Ortho), ABOS Assist. Professor, King Saud University Consultant Orthopedic and Arthroplasty Surgeon

2. objectives • To know mechanisms of the most common joint dislocations • Be able to make the diagnosis • To know and interpret the appropriate x-rays • To know the common complications and how to avoid them

3. Acute Joint Dislocation • Complete separation of the articularsurface: Joint surfaces are no longer in contact • Position of distal to proximal fragment: Anterior, Posterior, Inferior, Superior

4. Acute Joint Dislocation • Usually results from high-energy trauma • They occur most frequently in young patients

5. Clinical Features • Painful; inability to move the limb • Abnormal shape of the joint • The limb is often held in a characteristic position • Careful NV exam before reduction is attempted.

6. Imaging X-rays • adequate views • Confirm the diagnosis • Rule out fractures i.e. a fracture-dislocation • Reduce before X-rays: knee, ankle • CT scan

7. Treatment • Urgent reduction: Closed; surgical if failed • Adequate pain relief; muscle relaxant; GA • Imaging after reduction: Post-reduction films • Immobilization • physiotherapy

8. Complications • Neurovascular injury: Knee, ankle • Avascular necrosis of bone • Recurrent dislocation: shoulder • Heterotopic ossification • Joint stiffness • Secondary osteoarthritis

9. ACUTE SHOULDER DISLOCATION • The most commonly dislocating joint • shallowness of the glenoid socket and wide extraordinary range of motion

10. ACUTE SHOULDER DISLOCATION • Anterior dislocation is the most common • Posterior dislocation is rare; less than 2%

11. ANTERIOR SHOULDER DISLOCATION • Fall on the outstretched hand (abduction & external rotation)

12. ANTERIOR SHOULDER DISLOCATION • The lateral outline of the shoulder may be flattened • Bulge may be felt just below the clavicle

13. ANTERIOR SHOULDER DISLOCATION • X-rays: antero-posterior and lateral (axillary) views: • Overlapping shadows of the humeral head and glenoidfossa

14. ANTERIOR SHOULDER DISLOCATION • The head usually lying below and medial to the socket • Rule out greater tubrosity fracture

15. ANTERIOR SHOULDER DISLOCATION • Avulsion of the antero-inferior glenoid labrum (Bankart lesion). • Indentation of the postero-lateral part of the humeral head (Hill–Sachs lesion)

16. ANTERIOR SHOULDER DISLOCATION Reduction • Different techniques: Kocher’s, Stimson’s, Milch’s, Hippocratic

17. ANTERIOR SHOULDER DISLOCATION Reduction • Kocher’s method

18. ANTERIOR SHOULDER DISLOCATION Complications • Recurrent dislocation: age at first dislocation • Rotator cuff tear: elderly • Axillary nerve injury; neuropraxia • Axillary artery injury • Shoulder stiffness: prolonged immobilization • Unreduced (undiagnosed) dislocation

19. POSTERIOR SHOULDER DISLOCATION • Indirect force producing marked internal rotation and adduction • Convulsion, or with an electric shock

20. POSTERIOR SHOULDER DISLOCATION • The diagnosis is frequently missed; more than 50% • The arm is held in internal rotation and is locked in that position • The front of the shoulder looks flat with a prominent coracoid

21. POSTERIOR SHOULDER DISLOCATION Imaging • The humeral head is medially rotated (electric light bulb) • (The empty glenoid sign) • Axillaryor Scapular view is essential • Rule out fractures; neck, glenoid or lesser tuberosity • CT

22. HIP DISLOCATION • High energy trauma • posterior (the commonest) • anterior

23. POSTERIOR HIP DISLOCATION • Road Traffic accident; knee striking against the dashboard • Limb is short, adducted, internally rotated and slightly flexed.

24. POSTERIOR HIP DISLOCATION • Rule out associated fractures; femur or acetabulum • Rule out sciatic nerve injury

25. POSTERIOR HIP DISLOCATION • Reduction

26. POSTERIOR HIP DISLOCATION • Reduction

27. POSTERIOR HIP DISLOCATION • Reduction; stable • CT scan: the best to demonstrate an acetabular fracture (or any bony fragment)

28. POSTERIOR HIP DISLOCATION • Sciatic nerve injury; 10% • Avascular necrosis of the femoral head ;10% • If reduction is delayed by more than 12 hours, it rises to over 40% • Hetrotopic ossification

29. ANTERIOR HIP DISLOCATION • Rare compared with posterior • The leg lies externally rotated, abducted and slightly flexed • Palpable head in the groin

30. KNEE DISLOCATION • High energy mechanism; RTA • The cruciate ligaments and one or both lateral ligaments are torn

31. KNEE DISLOCATION • If dislocated joint has reduced spontaneously; swelling and gross instability

32. KNEE DISLOCATION • If still dislocated; gross deformity

33. KNEE DISLOCATION • Repeated vascular examination is necessary; popliteal artery injury; risk compartment syndrome • Common peroneal nerve injury: 20 % of cases

34. KNEE DISLOCATION • X-ray: dislocation, fracture of the tibial spine (cruciate ligament avulsion), avulsion of the fibular styloid (collateral ligament avulsion)

35. KNEE DISLOCATION • Angiograpy

36. KNEE DISLOCATION • Urgent reduction • Immediate vascular intervention if needed • Acute or delayed reconstruction of the ligaments

37. KNEE DISLOCATION Complications • Instability • Stiffness

38. Summary • Dislocation is an orthopedic emergency and need urgent reduction • Anterior shoulder dislocation is the commonest • Obtain adequate imaging to rule out posterior shoulder dislocation • Acute unstable knee is a knee dislocation until proven otherwise • Always suspect vascular injuries with dislocated knee