Hip Dislocation

See Also

Types

Posterior Dislocation
1. Most common Hip Dislocation
2. Occurs when the hip dislocates while adducted and posterior force is applied
Anterior Dislocation
1. Occurs when hip dislocates while abducted and externally rotated

Causes
Native Hip Dislocations

High energy Motor Vehicle Accident
1. Knee impacts dashboard
Pedestrian struck by motor vehicle
Fall from height
Sports related injury

Causes
Prosthetic Hip Dislocations

Prosthetic Hip Dislocation is the most common complication of total hip arthroplasty (THA)
1. Occurs in 10% of all primary THA (and 28% of all revisions)
2. Mechanism is typically low energy injury (bending, squatting, standing from seated position)
Early Postoperative Dislocations (<3 months, and esp. in first 6 weeks)
1. Occurs prior to formation of mature scar tissue
2. Higher risk with prior hip surgery, lumbar Spinal Fusion, prosthetic impingement or neurologic deficits
3. Surgical factors may also increase dislocation risk depending on surgical approach and component orientation
4. Recurrent dislocation occurs in one third of those after their first prosthetic hip disolocation
Mid-Postoperative Dislocations (4 months to 5 years)
1. Component malposition
2. Prosthetic impingement
3. Abductor mechanism dysfunction
Late Postoperative Dislocations (>5 years, may benefit from surgical revision)
1. Component malposition
2. Wearing down of acetabular polyethylene liner

Risk Factors
Prosthetic Hip Dislocation

Age over 70 years
Female gender
Musculoligamentous laxity
Abductor Muscle Weakness
Altered spinopelvic mechanics
Prior hip revision surgery
Improper cup placement
Failed recreation of limb length and offset
Posterolateral surgical approach

Mechanism

Femoral head driven out of acetabulum

History

See Trauma History
Mechanism of Hip Dislocation
Posthetic Hip surgical history
1. Date of hip replacement (<3 months or >5 years)
2. Surgical approach to hip replacement
3. Prior dislocations
4. Range of motion restrictions followed by patient?

Exam

See Hip Exam
Start with a General Trauma Evaluation with Secondary Survey
1. See Trauma Evaluation
2. Motor Vehicle Accidents with Hip Dislocation are associated with other injuries in two thirds of patients
  1. Closed Head Injury (24%)
  2. Craniofacial Fracture (21%)
  3. Thoracic Injury (21%)
  4. Abdominal Injury (15%)
  5. Mandell (2017) Radiographics 37(7): 2181-201a
Standard Musculoskeletal Trauma Evaluation
1. Joint Above and Joint Below
2. Sensory
  1. Dorsal foot and plantar foot Sensation
  2. Lateral and medial foot and leg Sensation
3. Motor (sciatic nerve evaluation)
  1. Flex and extend toes
  2. Plantar flex and dorsiflex foot
4. Vascular
  1. Femoral pulse
  2. Posterior tibial pulse and dorsalis pedis pulse
  3. Capillary Refill
5. Skin and Compartments
Inspect Region of Pelvis, Hip and Leg
1. Evaluate for deformity, swelling, Ecchymosis
Hip Range of Motion
1. Perform passive and active range of motion if patient able
Palpate from hip to distal extremity
1. Evaluate for deformity, swelling, instability or significant tenderness
Pelvic Compression Test
1. Instability may suggest unstable Pelvic Fracture
Log Roll Test
1. Identify Fracture sites along the ipsilateral leg

Signs

Leg shortened with most dislocated hips
Posterior Dislocation (most common)
1. Hip flexed, adducted and internally rotated
Anterior Dislocation
1. Hip slightly flexed, abducted and externally rotated

Differential Diagnosis

See Hip Pain Causes

Imaging
Pre-Reduction

Anteroposterior Pelvis XRay (AP Pelvis XRay)
1. Posterior Hip Dislocation (most common)
  1. Femoral head appears smaller than the unaffected side
  2. Acetabulum is not matched with femoral head
  3. Lesser trochanter is difficult to visualize due to hip internal rotation
2. Anterior Hip Dislocation
  1. Femoral head appears larger than the unaffected side
  2. Lesser trochanter is easily visualized
  3. Position of femoral head determines subtype (obturator, pubic or iliac dislocation)
Lateral Hip XRay (or dedicated femur XRay)
1. Also defines anterior or posterior dislocation
2. Assess for Hip Fracture, Pelvic Fracture, Femoral Shaft Fracture
CT Pelvis
1. Indicated if suspected femoral head, neck or Intertrochanteric Fracture BEFORE attempted reduction
2. Urgent open reduction required if Fracture dislocation is present

Imaging
Post-Reduction

Anteroposterior Pelvis (AP Pelvis) with Unilateral Hip
1. Obtain in all patient after reduction to confirm proper alignment
CT Pelvis
1. Consider in Traumatic, native Hip Dislocation
2. Occult Fractures (intraarticular, acetabular) are common

Management
Hip Reduction

Setting
1. Emergency Department
  1. Most hip reductions are performed in the Emergency Department under Procedural Sedation
2. Operating Room (Orthopedics)
  1. Indicated for Fracture, failed reduction
3. Sports Field
  1. Closed reduction has been performed on field immediately after Hip Dislocation
  2. Typically unsuccessful unless performed immediately, as large hip Muscles are difficult to overpower
Procedural Sedation
1. Deeper Procedural Sedation is required to allow for maximal hip relaxation
2. Difficult reduction is often due to inadequate sedation
3. Regional Anesthesia may be considered but may not offer adequate hip relaxation
Posterior Hip Reduction Techniques
1. Allis Maneuver
  1. Patient supine with affected knee flexed
  2. Assistant stabilizes Pelvis, and lateral traction to inner thigh
  3. Examiner stands on bed above the patient
    1. Apply longitudinal traction in-line with femur
    2. Hip is slightly flexed and then gradually flexed more to 90 degrees
    3. Adduct the hip and internally rotate the femur
    4. Gently rotate the hip internally and externally until hip reduction is achieved
    5. Gentle extension and external rotation will ultimately relocate the hip into the acetabulum
2. Bigelow Maneuver
  1. Patient supine with knee flexed to 90 degrees
  2. Assistant applies downward pressure to Pelvis (at ASIS)
  3. Examiner grasps ipsilateral ankle with one hand, and the popliteal space with the other
    1. Apply longitudinal traction in line with hip
    2. Apply gentle extension, abduction, and external rotation to femoral head to level back into acetabulum
3. Captain Morgan Technique (author's preferred method)
  1. Patient supine with hip flexed to 90 degrees and knee flexed to 90 degrees
  2. Assistant applies downward pressure on Pelvis against the bed
  3. Examiner (typically using a step stool), places one foot onto the bed with examiner knee under patient knee
    1. Examiner grasps the ipsilateral ankle and pulls down
    2. Examiner planter flexes foot, forcing the ipsilateral hip upwards towards the acetabulum
  4. Resources
    1. https://www.aliem.com/trick-of-trade-captain-morgan-technique/
    2. http://regionstraumapro.com/post/10201631357
4. East Baltimore Lift
  1. Patient lies supine with ipsilateral hip and knee flexed to 90 degrees
  2. One assistant stands on the contralateral side facing patient's head
    1. Assistant hooks their arm under the ipsilateral knee, resting their hand on the opposite assistant's Shoulder
    2. Free hand is used to apply downward pressure on the Pelvis
  3. Other assistant stands on the ipsilateral side facing patient's head
    1. Assistant hooks their arm under the ipsilateral knee, resting their hand on the opposite assistant's Shoulder
    2. Free hand is used to apply downward pressure on the Pelvis
  4. Both assistants apply longitudinal, upward force, inline at the knee
  5. Examiner stands on the foot of the bed, grasping the distal lower leg and ankle
    1. As the hip reduces, apply internal and external rotation, adduction and abduction as needed
5. Rochester Method (Tulse Technique, Whistler Technique)
  1. Patient supine with both knees flexed
  2. Examiner stands on ipsilateral side facing the hip
    1. Arm closest to the head is hooked UNDER the ipsilateral knee and grasps OVER the contralateral knee
    2. Other hand grasps the ipsilateral ankle applying internal and external rotation as the hip reduces
6. Waddell Technique
  1. Modified from Allis Maneuver and Bigelow Maneuever for less back strain for examiner
  2. Patient lies supine with ipsilateral hip flexed to 60-90 degrees and knee flexed to 90 degrees
  3. Assistant stabilizes Pelvis by applying downward pressure
  4. Examiner squats on bed
    1. Examiner places one hand on the assistant's Shoulder for support
    2. Examiner hooks their Forearm under the patient's ipsilateral knee and grasps their own knee
      1. Patient's ipsilateral leg is between the examiner's knees
    3. Examiner applies longitudinal traction by leaning backwards
    4. Examiner may also apply internal and external rotation to the hip as it reduces
Anterior Hip Reduction Techniques
1. Allis Leg Extension Method
  1. Patient supine
  2. Assistant stabilizes Pelvis against bed
  3. Examiner grasps ipsilateral knee and applies longitudinal traction, in-line with the hip
    1. May also apply external rotation or hip flexion
2. Reverse Bigelow Maneuver
  1. Patient supine
  2. Examiner
    1. One hand grasps the ipsilateral ankle
    2. Other hand grasps behind the ipsilateral knee
    3. Examiner applies inline, longitudinal traction
    4. Hip adduction, extension, internal or external rotation may be added
Either Anterior or Posterior Reduction
1. Lateral Traction Technique
  1. Patient supine with knee extended
  2. Assistant wraps hands or a sheet around the upper inner, ipsilateral thigh
    1. Assistant pulls laterally
  3. Examiner grasps lower leg and applies longitudinal traction in line with hip
    1. Internal rotation may assist reduction as the hip begins to reduce
2. Stimson Gravity Method
  1. Patient prone and lower legs hang over the edge of the bed with hip and knee flexed to 90 degrees
  2. Assistant applies downward pressure on Sacrum
  3. Examiner grasps the ipsilateral lower leg (below knee) and applies downward pressure
    1. Consider gentle internal and external rotation to aid reduction
Resources
1. Hip Reduction Trauma (Kelly Barringer, MD)
  1. https://www.youtube.com/watch?v=VYl6M87Uh68

Management
Post-Reduction Restrictions after Traumatic Hip Dislocation

Protected weight bearing (or toe touch only weight bearing) for 4-6 weeks
1. https://www.youtube.com/watch?v=Dne_Asm6CGw
Abduction pillow (placed between the legs)
Keep toes pointing up (not internally or externally rotated) whioe lying supine
Avoid flexion of hip >90 degrees
Avoid hip crossing the midline of body
Avoid hip internal rotation
Physical rehabilitation Exercises
1. Hip strengthening Exercises
Delay return to sport for 6-12 weeks

Management
Orthopedic Consultation Indications

Emergent Consultation Indications
1. Proximal Femur Fracture
2. Acetabular Fracture with instability (operative fixation indication)
  1. Posterior wall fragment >33% OR
  2. Positive intraoperative fluoroscopic stress views
3. Hip that cannot be reduced with maneuvers above while under adequate Procedural Sedation
4. Prolonged Hip Dislocation
5. Safe Procedural Sedation is not possible due to patient's condition
6. Status-post total hip arthroplasty (THA) concerns
  1. THA within the last 6 weeks (Risk related to unhealed surgical incision)
  2. Previously reconstructed acetabulum
  3. Peri-prosthetic Fracture or broken implant
  4. Grossly loose femoral implant or cup
  5. Complex THA implants (e.g. constrained liners, dual-mobility femoral head implant)
Other Urgent Referral Indications
1. Marginal Impaction
  1. Subchondral bone rotation and impaction into the underlying cancellous bone
  2. Requires elevation and bone grafting
  3. Risk of Hip Osteoarthritis if not addressed early
2. Intraarticular debris within Hip Joint
  1. Requires skeletal traction to prevent chondral injury until open repair
3. Intraprosthetic Dislocation
  1. Large, polyethylene femoral head separates from the smaller femoral head
  2. Requires early revision surgery to prevent instability
  3. Identified on post-reduction XRay
    1. Femoral head will appear off center within acetabulum
    2. Adjacent soft tissue will demonstrate a halo representing the separated polyethylene ring
Routine referral
1. Status-post Total Hip Arthroplasty (notify orthopedics of dislocation)

Complications
Traumatic, Native Hip Dislocations

Hip Avascular Necrosis
1. Onset within 2 years of injury
2. Increased risk if delayed hip relocation due to disruption of arterial supply
  1. Risk increases from 4.8% if reduced in under 6 hours to nearly 53% if delayed >6 hours
Post-Traumatic Arthritis
1. Prevalence 24% after Traumatic Hip Dislocation (esp. in heavy manual labor)
Sciatic Nerve Injury (esp. Peroneal Nerve)
1. Surgical exploration is indicated for sciatic nerve distrubution Neuropathy persisting after relocation
References
1. Sanders (2010) Bull NYU Hosp Jt Dis 68(2): 91-6 [PubMed]

Resources

Hip Dislocation (Core EM)
1. https://coreem.net/core/hip-dislocation/
Hip Reduction Maneuvers (Waddell, et. al.)
1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4821229/

References

Kirwin, Conroy, McGrath (2021) Crit Dec Emerg Med 35(7): 15-24
Shaner (2022) Crit Dec Emerg Med 16-7
Dawson-Amoah (2018) Ochsner J 18(3):242-252 +PMID: 30275789 [PubMed]