Hip Dislocation

Author: Brian Weatherford

Topic updated on 04/08/13 1:12pm

Introduction

Epidemiology
- rare, but high incidence of associated injuries
- mechanism is usually young patients with high energy trauma
Hip joint inherently stable due to
- bony anatomy
- soft tissue constraints including
  - labrum
  - capsule
  - ligamentum teres

Classification

Simple vs. Complex
- simple
  - pure dislocation without associated fracture
- complex
  - dislocation associated with fracture of acetabulum or proximal femur
Anatomic classification
- posterior dislocation (90%)
  - occur with axial load on femur, typically with hip flexed and adducted
    - axial load through flexed knee (dashboard injury)
  - position of hip determines associated acetabular injury
    - increasing flexion and adduction favors simple dislocation
  - associated with
    - osteonecrosis
    - posterior wall acetabular fracture
    - femoral head fractures
    - sciatic nerve injuries
    - ipsilateral knee injuries (up to 25%)
- anterior dislocation
  - associated with femoral head impaction or chondral injury
  - occurs with the hip in abduction and external rotation
  - inferior vs. superior
    - hip extension results in a superior (pubic) dislocation
    - flexion results in inferior (obturator) dislocation

Presentation

Symptoms
- acute pain, inability to bear weight, deformity
Physical exam
- ATLS
  - 95% of dislocations with associated injuries
- posterior dislocation (90%)
  - hip and leg in slight flexion, adduction, and internal rotation
  - detailed neurovascular exam (10-20% sciatic nerve injury)
  - examine knee for associated injury or instability
- anterior dislocation
  - hip and leg in flexion, abduction, and external rotation

Imaging

Radiographs
- can typically see posterior dislocation on AP pelvis
  - femoral head smaller then contralateral side
  - Shenton's line broken
  - lesser trochanter shadow reveals internally rotated limb as compared to contralateral side
  - scrutinize femoral neck to rule out fracture prior to attempting closed reduction
CT
- helps to determine direction of dislocation, loose bodies, and associated fractures
  - anterior dislocation
  - posterior dislocation
- post reduction CT must be performed for all traumatic hip dislocations to look for
  - femoral head fractures
  - loose bodies
  - acetabular fractures
MRI
- controversial and routine use is not currently supported
- useful to evaluate labrum, cartilage and femoral head vascularity

Treatment

Nonoperative
- emergent closed reduction within 6 hours
  - indications
    - acute anterior and posterior dislocations
  - contraindications
    - ipsilateral displaced or non-displaced femoral neck fracture
Operative
- open reduction and/or removal of incarcerated fragments
  - indications
    - irreducible dislocation
    - radiographic evidence of incarcerated fragment
    - delayed presentation
    - non-concentric reduction
    - should be performed on urgent basis
- ORIF
  - indications
    - associated fractures of
      - acetabulum
      - femoral head
      - femoral neck
        
        should be stabilized prior to reduction
- arthroscopy
  - indications
    - no current established indications
    - potential for removal of intra-articular fragments
    - evaluate intra-articular injuries to cartilage, capsule, and labrum

Techniques

Closed reduction
- perform with patient supine and apply traction in line with deformity regardless of direction of dislocation
- must have adequate sedation and muscular relaxation to perform reduction
- assess hip stability after reduction
- post reduction CT scan required to rule out
  - femoral head fractures
  - intra-articular loose bodies/incarcerated fragments
    - may be present even with concentric reduction on plain films
    - acetabular fractures
- post-reduction
  - for simple dislocation, follow with protected weight bearing for 4-6 weeks
Open reduction
- approach
  - posterior dislocation
    - posterior (Kocher-Langenbeck) approach
  - anterior dislocation
    - anterior (Smith-Petersen) approach
- technique
  - may place patient in traction to reduce forces on cartilage due to incarcerated fragment or in setting of unstable dislocation
  - repair of labral or other injuries should be done at the same time

Complications

Post-traumatic arthritis
- up to 20% for simple dislocation, markedly increased for complex dislocation
Femoral head osteonecrosis
- 5-40% incidence
- Increased risk with increased time to reduction
Sciatic nerve injury
- 8-20% incidence
- associated with longer time to reduction
Recurrent dislocations
- less than 2%

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Qbank (2 Questions)

TAG

(OBQ08.200) A 41-year-old female sustains the injury shown in Figure A as a result of a high-speed motor vehicle collision. After a successful attempt at closed reduction in the emergency room using conscious sedation, repeat radiographs show a reduced hip joint. What is the next most appropriate step in treatment? Topic

Review Topic

FIGURES: A

1. Femoral skeletal traction
2. CT scan of hip and pelvis
3. Dynamic fluoroscopic examination under general anesthesia
4. Hip spica dressing
5. Touch down weight bearing mobilization

PREFERRED RESPONSE ▶

DISCUSSION: The radiograph shown in Figure A reveals a left hip dislocation, with some obscuring of detail secondary to the trauma backboard. CT scans should be obtained following a hip dislocation to evaluate for fractures or impacted areas of the femoral head or acetabulum, as well as noncongruent reductions and free intraarticular joint fragments.

The referenced study by Brumback et al comments on the importance of post-reduction CT scans and found that 23% of their posterior wall fractures had associated marginal impaction, with 94% of these discovered via preoperative CT scan.

REFERENCES:

1. Brumback RJ, Holt ES, McBride MS, Poka A, Bathon GH, Burgess AR. Acetabular depression fracture accompanying posterior fracture dislocation of the hip. J Orthop Trauma. 1990;4(1):42-8. PMID:2313429 (Link to Abstract)

Question Authors:

Ben Taylor MD, Jan Szatkowski MD,

Please Rate Educational Value!

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TAG

(OBQ07.128) A 30-year-old driver is involved in a motor vehicle collision and sustains the injury shown in Figure A. What is the most likely concomitant injury? Topic

Review Topic

FIGURES: A

1. Right knee meniscus tear
2. Left knee ACL tear
3. Subdural hematoma
4. Right ankle fracture-dislocation
5. Lumbar burst fracture

PREFERRED RESPONSE ▶

DISCUSSION: Traumatic hip dislocation results from the dissipation of a large amount of energy about the hip joint. Clinically, these forces often are first transmitted through the knee en route to the hip. It is therefore logical to look for coexistent ipsilateral knee injury in patients with a traumatic hip dislocation.

Schmidt, et al, prospectively evaluated the ipsilateral knee of all patients who had a traumatic hip dislocation and found that 93% had abnormalities on MRI of the knee, with effusion (37%), bone bruise (33%), and meniscal tear (30%) being the most common findings. They suggest liberal use of MRI to the ipsilateral knee if injury is suspected.

REFERENCES:

1. Schmidt GL, Sciulli R, Altman GT: Knee injury in patients experiencing a high-energy traumatic ipsilateral hip dislocation. J Bone Joint Surg Am 2005; 87: 1200-1204 PMID:15930527 (Link to Abstract)

Question Authors:

Greg Galano MD, Ben Taylor MD, Jan Szatkowski MD,

Please Rate Educational Value!

3.0

Average 3.0 of 28 Ratings

Cases

posterior dislocation of hip 8 months (C1270)

Trauma - Treatment Consult - Hip Dislocation

HPI - fell from motor cycle 9 months ago, is walking with a limp.Has had no treatment.

treatment with limited resourses

9/13/2012

38 responses

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Videos

	Mechanism of Acute Hip Dislocation in Football Player Sports - Physical Exam - Hip Dislocation This video shows the mechanism of an acute hip dislocation in a football player....	1/3/2012 220 views 4
	Closed Reduction of Dislocated hip. Trauma - Techniques - Hip Dislocation This video demonstrates reduction of a dislocated hip and the placement of a fem...	1/3/2012 1283 views 5

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Groups

ABOS II: Hip Dislocation

General - Oral Boards Review

7/29/2011

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Evidence & References Show References

Textbooks

Review of Orthopaedics, 6th Edition, Mark D. Miller MD, Stephen R. Thompson MBBS MEd FRCSC, Jennifer Hart MPAS PA-C ATC, an imprint of Elsevier, Philadelphia, Copyright 2012
AAOS Comprehensive Orthopaedic Review, Jay R. Leiberman. Published by American Academy of Orthopaedic Surgeons, Rosemont IL. Copyright 2009
Orthopaedic Knowledge Update 10, John M Flyn. Published by American Academy of Orthopaedic Surgeons, Rosemont IL. Copyright 2011
Hoppenfeld SP. Surgical Exposures in Orthopaedics: The Anatomic Approach. Lipponcott, Williams, and Wilkins, Philadelphia, PA, Copyright 2009
Orthopaedic In-training Examination (OITE) Questions 2004-2012, American Academy of Orthopaedic Surgeons, Rosemont IL. Copyright 2004-2012
Self-Assessment Examination (SAE) Questions 2004-2012, American Academy of Orthopaedic Surgeons, Rosemont IL. Copyright 2004-2012

Undefined

Brumback RJ, Holt ES, McBride MS, Poka A, Bathon GH, Burgess AR. Acetabular depression fracture accompanying posterior fracture dislocation of the hip. J Orthop Trauma. 1990;4(1):42-8. PMID:2313429 (Link to Abstract)
Schmidt GL, Sciulli R, Altman GT: Knee injury in patients experiencing a high-energy traumatic ipsilateral hip dislocation. J Bone Joint Surg Am 2005; 87: 1200-1204 PMID:15930527 (Link to Abstract)

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Hip Dislocation

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