Hip dislocation etiology management.pptx

Hip dislocation

1. HIP DISLOCATION

2. Hip dislocations are traumatic hip injuries that result in femoral head dislocation from the acetabular socket. Incidence is rare, mechanism is usually young patients with high energy trauma

3. ​ I. Introduction & Epidemiology ​Hip dislocations are significant orthopedic injuries, almost always resulting from high-energy trauma. They represent a true orthopedic emergency, as prompt reduction is critical to improving outcomes. ​ Incidence: Most common in males aged 16 to 40, primarily due to motor vehicle accidents. ​ Direction: ​ Posterior Dislocations: Account for 85% to 90% of cases. ​ Anterior Dislocations: Account for 10% to 15% of cases. . ​ Associated Injuries: Up to 50% of patients have concomitant fractures elsewhere. Sciatic nerve injury is present in 10% to 20% of posterior dislocations.

4. Anatomy ​ Bony Anatomy: The hip is a highly congruent ball-and-socket joint. The acetabulum covers approximately 40% of the femoral head, and this is deepened by the fibrocartilaginous labrum . ​ Capsuloligamentous Structures: ​The hip joint capsule is reinforced by strong ligaments: the iliofemoral , pubofemoral , and ischiofemoral ligaments. These run in a spiral fashion and are essential for stability, particularly in preventing hyperextension. ​

5. Vascular Supply: ​The primary blood supply to the femoral head comes from the medial and lateral femoral circumflex arteries, which are branches of the profunda femoris artery. ​These form an extracapsular ring at the base of the femoral neck, from which ascending cervical branches arise to supply the head. Disruption of this supply is the primary cause of osteonecrosis. . ​ Neural Anatomy: The sciatic nerve exits the pelvis at the greater sciatic notch and courses deep to the piriformis muscle, making it vulnerable to injury in posterior dislocations.

6. Mechanism of Injury ​ Posterior Dislocation: ​This is the most common type and typically results from a force applied to a flexed knee with the hip also in flexion, as seen in a dashboard injury. ​If the hip is in a neutral or adducted position, a pure dislocation is likely. ​If the hip is in abduction, an associated fracture of the posterior acetabular rim is common. ​

7. Anterior Dislocation: ​This results from a combination of abduction and external rotation. ​ Inferior (Obturator) Type: Occurs with the hip in flexion. ​ Superior (Iliac or Pubic) Type: Occurs with the hip in extension.

8. Clinical Evaluation ​ Initial Assessment: A full trauma survey (ATLS protocol) is essential. ​ Physical Examination: ​ Posterior Dislocation: The patient presents with the limb in a characteristic position of flexion, adduction, and internal rotation. ​ Anterior Dislocation: The patient holds the limb in external rotation, with some abduction and mild flexion. ​

9. Neurovascular Assessment: ​ Sciatic Nerve: Must be assessed in all posterior dislocations. The peroneal division is more commonly affected than the tibial division. ​ Femoral Artery, Vein, and Nerve: These structures are at risk in anterior dislocations.

10. Radiographic Evaluation ​ Initial Radiographs: An anteroposterior (AP) view of the pelvis and a cross-table lateral view of the affected hip are required. ​On the AP view, a posteriorly dislocated femoral head will appear smaller than the contralateral side, while an anteriorly dislocated head will appear larger. ​The Shenton line should be assessed for disruption. ​The femoral neck must be evaluated to rule out a fracture before attempting reduction.

11. Classification ​ Posterior Dislocations (Thompson and Epstein) ​ Type I: Simple dislocation, with or without a minor posterior wall fragment. ​ Type II: Dislocation with a large, single posterior wall fragment. ​ Type III: Dislocation with a comminuted posterior wall fragment. ​ Type IV: Dislocation with a fracture of the acetabular floor. ​ Type V: Dislocation with a fracture of the femoral head.

12. Anterior Dislocations (Epstein) ​ Type I (Superior): Pubic or subspinous location. ​IA: No associated fracture. ​IB: Associated femoral head fracture or impaction. ​IC: Associated acetabulum fracture. ​ Type II (Inferior): Obturator or perineal location. ​IIA: No associated fracture. ​IIB: Associated femoral head fracture or impaction. ​IIC: Associated acetabulum fracture.

13. Treatment ​The primary goal is urgent, concentric reduction of the hip to minimize the risk of osteonecrosis. The prognosis worsens if reduction is delayed more than 12 hours.

14. R ochester Method The surgeon performing the reduction maneuver stands on the side of the patient’s affected extremity. The patient’s hips and knees are flexed to 90 degrees bilaterally. An assistant supports the contralateral hip and maintains knee flexion . The surgeon’s more cephalad arm is passed beneath the patient’s proximal calf and placed on the contralateral patella, while the more caudal arm is used to control the patient’s ipsilateral ankle and foot A second assistant stabilizes the pelvis if needed. The surgeon internally rotates the extremity before using the contralateral patella as a fulcrum to apply an anterior-directed force to reduce.

15. The East Baltimore lift Can be used in patients with contralateral lower extremity injuries. The surgeon performing the reduction maneuver stands on the side of the patient’s affected extremity. The patient’s ipsilateral hip and knee are flexed to 90 degrees. The surgeon’s more cepha - lad arm is passed beneath the patient’s proximal calf and placed on an assistant’s shoulder. The surgeon’s more caudal arm is used to control the patient’s ankle and rotate the extremity if necessary. A second assistant stabilizes the pelvis as needed. The surgeon internally rotates the extremity, and the surgeon and first assistant then stand (extending at the hips and knees), resulting in an anterior-directed force to reduce the dislocation.

16. Allis maneuver Can be done with one less assistant than the East Baltimore lift. The patient is positioned supine, an assistant stabilizes the pelvis, and the surgeon applies traction in the direction opposite the deformity. While traction is being applied, the hip is flexed to 90 degrees and the extremity is internally and externally rotated as necessary to achieve reduction.

17. Bigelow maneuver The patient is positioned supine, and an assistant stabilizes the pelvis. The surgeon places one arm beneath the patient’s proximal calf and grasps the ankle with his or her other arm. The surgeon applies traction in the direction opposite the deformity and then flexes the hip to 90 degrees. Traction is maintained at 90 degrees of flexion, keeping the extremity adducted and internally rotated. The femoral head is then levered into the acetabulum with a combination of abduction, external rotation, and extension of the hip.

18. Post-Reduction Protocol ​Once closed reduction is achieved, a strict protocol must be followed: ​ Confirm Reduction: An AP pelvis radiograph must be obtained to confirm the adequacy of the reduction. ​ Assess Stability: While the patient is still sedated, the hip's stability should be checked. This is typically done under fluoroscopy by flexing the hip to 90 degrees and applying a gentle posterior force. Any sensation of subluxation indicates instability that may require traction or surgical intervention. ​ Obtain a CT Scan: A CT scan is essential after every closed reduction of a hip dislocation to rule out intra-articular bone fragments and to fully evaluate associated femoral head or acetabular fractures.

19. Open Reduction ​Surgical intervention is required when closed methods fail or are contraindicated. ​ Indications for Open Reduction: ​A dislocation that is irreducible by closed means. ​A nonconcentric reduction, which suggests interposed soft tissue (like the labrum ) or a bone fragment. ​An associated fracture of the acetabulum or femoral head that requires open reduction and internal fixation (ORIF). ​An ipsilateral femoral neck fracture . Crucially, closed reduction should not be attempted in this scenario , as it can displace the neck fracture and further compromise blood supply.

20. Surgical Approaches: ​ Posterior (Kocher- Langenbeck ): Used for posterior dislocations, allowing for sciatic nerve exploration and fixation of posterior wall fractures. ​ Anterior (Smith-Petersen): Recommended for isolated femoral head fractures. ​ Anterolateral (Watson-Jones): Useful for anterior dislocations and combined femoral head and neck fractures.

21. Complications: ​ Osteonecrosis (Avascular Necrosis): This is the most feared complication, occurring in 5% to 40% of cases. The risk increases significantly if reduction is delayed beyond 6-24 hours. ​ Posttraumatic Osteoarthritis: This is the most frequent long-term complication, especially when associated with acetabular or femoral head fractures. ​ Sciatic Nerve Injury: Occurs in 10% to 20% of cases, with about 40-50% achieving full recovery. ​ Recurrent Dislocation: This is rare, occurring in less than 2% of traumatic cases. ​ Associated Femoral Head Fractures: Occur in 10% of posterior dislocations and 25-75% of anterior dislocations. ​ Heterotopic Ossification: Occurs in about 2% of patients.

22. Key Takeaways ​Hip dislocation is a high-energy orthopedic emergency . ​The vascular supply to the femoral head is tenuous and at high risk. ​ Urgent reduction (<12 hours) is critical to minimize the risk of osteonecrosis. ​Always perform a thorough neurovascular exam before and after reduction. ​A post-reduction CT scan is mandatory to ensure a concentric reduction and rule out associated injuries.