PELVIS & ACETABULUM Orthopaedics topics slides

Orthopaedics

1. PELVIS & ACETABULUM

2. INTRODUCTION Fractures of the pelvis account for less than 5% of all skeletal injuries particularly important due to the potential risk of severe blood loss over 10% of these patients will have associated visceral injuries in this group the mortality rate is in excess of 10%

3. ANATOMY PELVIC RING 2 innominate bones sacrum articulating in front at the symphysis pubis posteriorly at the sacroiliac joints Unlike a hinge joint or a ball-and-socket joint, the pelvic bones do not articulate as part of a stable construct stability of the pelvic ring depends upon the integrity of the strong ligaments that bind the three segments together

4. ANTERIOR STABILITY at symphysis pubis is provided by- 1. superior pubic ligament 2. arcuate pubic ligament POSTERIOR STABILITY at sacro -iliac joints is provided by- Anteriorly Posteriorly anterior sacroiliac ligaments posterior sacroiliac ligaments iliolumbar ligaments sacrococcygeal ligaments Sacrotuberous ligaments sacrospinous ligaments

5. Blood vessels in pelvis major branches of the common iliac arteries and veins arise within the pelvis internal iliac vessels - supply the pelvic viscera external iliac vessels - continue in their journey to supply the lower limbs rich low-pressure venous plexus posteriorly - especially prone to injury if there is bony disruption around the sacroiliac joints It is bleeding from this plexus that comprises the major blood loss in pelvic haemorrhage

6. L5 and S1 nerve roots - most commonly damaged nerves in pelvic ring injuries sciatic nerve - most commonly damaged in acetabular fractures.

7. bladder lies behind the symphysis pubis urethra is much more mobile and shorter in females, and it is less prone to injury. In severe pelvic injuries the membranous urethra is damaged

8. FUNCTIONS OF THE PELVIS Its primary role is to support the weight of the upper body when sitting and to transfer this weight to the lower limbs when standing serves as an attachment point for trunk and lower limb muscles also protects the internal pelvic organs .

9. CLINICAL ASSESSMENT fracture of the pelvis should be suspected in any multiply injured patient swelling and bruising of the lower abdomen, the thighs, the perineum, the scrotum or the vulva abdomen should be carefully palpated. Guarding or tenderness suggests the possibility of intraperitoneal bleeding A ruptured bladder should be suspected in patients who do not void or in whom a bladder is not palpable after adequate fluid replacement

10. Neurological examination is very important; there may be damage to the lumbosacral plexus

11. IMAGING OF THE BONY PELVIS plain anteroposterior (AP) X-ray of the pelvis is obtained at the same time as the chest X-ray carefully Inspected, systematically looking in each of the five zones of injury: 1. The sacroiliac joint area is inspected for any diastasis or sacral fracture. 2. The ilium is inspected for any fracture 3. The teardrop is inspected. correlates to the non-articular floor of the acetabulum 4. The obturator foramen is inspected for any fracture of the superior or inferior pubic ramus. 5. The symphysis pubis is examined for any fracture or diastasis.

12. SPECIALIZED RADIOGRAPHS FOR PELVIS 1. INLET VIEW 30–40 degrees in a caudal angle provides an axial view of the sacrum and sacroiliac joints 2. OUTLET VIEW 30–40 degrees cephalic angle true anteroposterior view of the sacrum and pubic symphysis areas

13. Judet views (taken at 30 degrees obliquely) obturator oblique view iliac oblique view shows the anterior column of the acetabulum shows the posterior column and anterior wall of the acetabulum.

14. CT SCANS CT scanning provides a detailed anatomical view of the posterior structures, which are not seen well on conventional radiographs Contrast is often also given. This is very helpful in excluding a bladder rupture or urethral injury full ‘trauma CT scan’- This comprises a CT scan of the head, neck, chest, abdomen and pelvis.

15. PELVIC FRACTURES- 1. AVULSION FRACTURES most common avulsion injuries- anterior inferior iliac spine (rectus femoris origin) and the ischial tuberosity (hamstring origin) Usually seen in sportsmen and women and athletes All are essentially muscle injuries, needing only rest for a few days If there is a large bony fragment with displacement, however, operative fixation may be necessary

16. 2. STRESS FRACTURES Fractures of the pubic rami are fairly common in osteoporotic bone MRI is very helpful for the diagnosis of posterior insufficiency fractures (around the sacroiliac joints) also seen in the superior and inferior pubic rami in slim individuals and long-distance runners Consideration should be given to checking vitamin D levels Patients usually heal with rest

17. PELVIC RING FRACTURES usually due to a high-energy injury Think of the pelvis as a ‘polo mint’. It is impossible to break a polo mint in one place. The same principle applies to the normal bony pelvic ring Anteriorly the symphysis pubis or pubic rami will be disrupted, and posteriorly there will either be a sacroiliac joint displacement or sacral fracture

18. CLASSIFICATION OF PELVIC RING FRACTURES Young and Burgess based on the mechanism of injury predictive of the severity of the injury (blood loss) and also guides the surgeon on how to correct any deformity or displacement of the fracture Tile classification provides an assessment of stability of the pelvis guides the surgeon as to whether an injury needs operative fixation.

19. TREATMENT initial management must follow the ATLS protocol to the injured patient. PELVIC BINDERS- applied at the level of greater trochanters of the hips effective in closing the pelvic volume, and providing temporary stability If a binder is in situ, and there is persistent haemodynamic instability, immediate haemorrhage control is required.

20. Pubic diastasis before application of pelvic binder After application of pelvic binder

21. Pelvic C-clamp The Pelvic C-Clamp is an emergency stabilization instrument for unstable injuries and fractures of the pelvic ring allows rapid reduction and stabilization of these unstable pelvic ring fractures comprised of rails and arms with a locking mechanism

22. Two options exist Angiography and embolization Immediate transfer to the operating theatre for pre-peritoneal packing

23. Operative fixation principle of operative fixation- to convert an unstable pelvic ring to a stable one Pubic symphysis diastasis is treated with open reduction and internal fixation with plates and screws

24. UROGENITAL INJURIES Bladder and urethral injury is the commonest associated injury in pelvic fractures Urethral tears are usually treated conservatively with catheterization for a few weeks If a soft, silicone 16F catheter cannot be passed by a single, gentle attempt, a suprapubic catheter is required Intraperitoneal rupture of the bladder requires emergency laparotomy and direct repair; extraperitoneal bladder rupture may be treated conservatively

25. COMPLICATIONS Urethral strictures Impotence- 30% in pelvic fractures Venous thromboembolism Nerve injury- L5,S1 roots Infection Non-union

26. ACETABULAR FRACTURES

27. INTRODUCTION  adult acetabulum contains components of the ilium, ischium, and pubis acetabulum contains anterior and posterior walls (or rims) but is open inferiorly as the acetabular notch  flat medial surface of the acetabulum that faces the pelvic organs is named the quadrilateral plate The postero -superior portion of the roof of the acetabulum has a major role during weight bearing

28. Acetabular fractures occur when the femoral head is driven into the acetabulum Direction of the force determines the fracture pattern Displaced fractures result in hip joint incongruency ; this will lead to osteoarthritis

29. LETOURNEL CLASSIFICATION examine the lines on the AP pelvic X-ray There are two groups: elemental fractures and associated fractures

30. AP VIEW OBTURATOR OBLIQUE VIEW ILIAC OBLIQUE VIEW

31. MANAGEMENT goal of treatment- restore joint congruency provide fracture stability to allow mobilization prevent osteoarthritis Undisplaced fractures are usually stable and can be managed conservatively Patients are mobilized with partial weight-bearing on the affected side for 6 weeks If the hip is dislocated, reduction is urgent, followed by the application of skeletal traction until definitive surgery

32. Fractures with more than 2 mm of displacement of the articular surface should be anatomically reduced and stabilized Patients with- >3 mm of displacement- poor outcome <1 mm displacement- have less progression to osteoarthritis. Surgical approaches: Ilioinguinal approach Kocher- langenbeck approach

33. COMPLICATIONS Heterotopic ossification Sciatic nerve palsy Avascular necrosis Hip abductor dysfunction Osteoarthritis

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