II. Types
- Posterior Dislocation
- Most common Hip Dislocation
- Occurs when the hip dislocates while adducted and posterior force is applied
- Anterior Dislocation
- Occurs when hip dislocates while abducted and externally rotated
III. Causes: Native Hip Dislocations
- High energy Motor Vehicle Accident
- Knee impacts dashboard
- Pedestrian struck by motor vehicle
- Fall from height
- Sports related injury
IV. Causes: Prosthetic Hip Dislocations
- Prosthetic Hip Dislocation is the most common complication of total hip arthroplasty (THA)
- Occurs in 10% of all primary THA (and 28% of all revisions)
- Mechanism is typically low energy injury (bending, squatting, standing from seated position)
- Early Postoperative Dislocations (<3 months, and esp. in first 6 weeks)
- Occurs prior to formation of mature scar tissue
- Higher risk with prior hip surgery, lumbar Spinal Fusion, prosthetic impingement or neurologic deficits
- Surgical factors may also increase dislocation risk depending on surgical approach and component orientation
- Recurrent dislocation occurs in one third of those after their first prosthetic hip disolocation
- Mid-Postoperative Dislocations (4 months to 5 years)
- Component malposition
- Prosthetic impingement
- Abductor mechanism dysfunction
- Late Postoperative Dislocations (>5 years, may benefit from surgical revision)
- Component malposition
- Wearing down of acetabular polyethylene liner
V. 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
VI. Mechanism
- Femoral head driven out of acetabulum
VII. History
- See Trauma History
- Mechanism of Hip Dislocation
- Posthetic Hip surgical history
- Date of hip replacement (<3 months or >5 years)
- Surgical approach to hip replacement
- Prior dislocations
- Range of motion restrictions followed by patient?
VIII. Exam
- See Hip Exam
- Start with a General Trauma Evaluation with Secondary Survey
- See Trauma Evaluation
- Motor Vehicle Accidents with Hip Dislocation are associated with other injuries in two thirds of patients
- Closed Head Injury (24%)
- Craniofacial Fracture (21%)
- Thoracic Injury (21%)
- Abdominal Injury (15%)
- Mandell (2017) Radiographics 37(7): 2181-201a
- Standard Musculoskeletal Trauma Evaluation
- Joint Above and Joint Below
- Sensory
- Motor (sciatic nerve evaluation)
- Flex and extend toes
- Plantar flex and dorsiflex foot
- Vascular
- Femoral pulse
- Posterior tibial pulse and dorsalis pedis pulse
- Capillary Refill
- Skin and Compartments
- Inspect Region of Pelvis, Hip and Leg
- Evaluate for deformity, swelling, Ecchymosis
-
Hip Range of Motion
- Perform passive and active range of motion if patient able
- Palpate from hip to distal extremity
- Evaluate for deformity, swelling, instability or significant tenderness
-
Pelvic Compression Test
- Instability may suggest unstable Pelvic Fracture
-
Log Roll Test
- Identify Fracture sites along the ipsilateral leg
IX. Signs
- Leg shortened with most dislocated hips
- Posterior Dislocation (most common)
- Hip flexed, adducted and internally rotated
- Anterior Dislocation
- Hip slightly flexed, abducted and externally rotated
X. Differential Diagnosis
- See Hip Pain Causes
XI. Imaging: Pre-Reduction
- Anteroposterior Pelvis XRay (AP Pelvis XRay)
- Posterior Hip Dislocation (most common)
- Femoral head appears smaller than the unaffected side
- Acetabulum is not matched with femoral head
- Lesser trochanter is difficult to visualize due to hip internal rotation
- Anterior Hip Dislocation
- Femoral head appears larger than the unaffected side
- Lesser trochanter is easily visualized
- Position of femoral head determines subtype (obturator, pubic or iliac dislocation)
- Posterior Hip Dislocation (most common)
- Lateral Hip XRay (or dedicated femur XRay)
- Also defines anterior or posterior dislocation
- Assess for Hip Fracture, Pelvic Fracture, Femoral Shaft Fracture
- CT Pelvis
- Indicated if suspected femoral head, neck or Intertrochanteric Fracture BEFORE attempted reduction
- Urgent open reduction required if Fracture dislocation is present
XII. Imaging: Post-Reduction
XIII. Management: Hip Reduction
- Setting
- Emergency Department
- Most hip reductions are performed in the Emergency Department under Procedural Sedation
- Operating Room (Orthopedics)
- Indicated for Fracture, failed reduction
- Sports Field
- Closed reduction has been performed on field immediately after Hip Dislocation
- Typically unsuccessful unless performed immediately, as large hip Muscles are difficult to overpower
- Emergency Department
-
Procedural Sedation
- Deeper Procedural Sedation is required to allow for maximal hip relaxation
- Difficult reduction is often due to inadequate sedation
- Regional Anesthesia may be considered but may not offer adequate hip relaxation
- Posterior Hip Reduction Techniques
- Allis Maneuver
- Patient supine with affected knee flexed
- Assistant stabilizes Pelvis, and lateral traction to inner thigh
- Examiner stands on bed above the patient
- Apply longitudinal traction in-line with femur
- Hip is slightly flexed and then gradually flexed more to 90 degrees
- Adduct the hip and internally rotate the femur
- Gently rotate the hip internally and externally until hip reduction is achieved
- Gentle extension and external rotation will ultimately relocate the hip into the acetabulum
- Bigelow Maneuver
- Patient supine with knee flexed to 90 degrees
- Assistant applies downward pressure to Pelvis (at ASIS)
- Examiner grasps ipsilateral ankle with one hand, and the popliteal space with the other
- Apply longitudinal traction in line with hip
- Apply gentle extension, abduction, and external rotation to femoral head to level back into acetabulum
- Captain Morgan Technique (author's preferred method)
- Patient supine with hip flexed to 90 degrees and knee flexed to 90 degrees
- Assistant applies downward pressure on Pelvis against the bed
- Examiner (typically using a step stool), places one foot onto the bed with examiner knee under patient knee
- Examiner grasps the ipsilateral ankle and pulls down
- Examiner planter flexes foot, forcing the ipsilateral hip upwards towards the acetabulum
- Resources
- East Baltimore Lift
- Patient lies supine with ipsilateral hip and knee flexed to 90 degrees
- One assistant stands on the contralateral side facing patient's head
- Other assistant stands on the ipsilateral side facing patient's head
- Both assistants apply longitudinal, upward force, inline at the knee
- Examiner stands on the foot of the bed, grasping the distal lower leg and ankle
- As the hip reduces, apply internal and external rotation, adduction and abduction as needed
- Rochester Method (Tulse Technique, Whistler Technique)
- Patient supine with both knees flexed
- Examiner stands on ipsilateral side facing the hip
- Arm closest to the head is hooked UNDER the ipsilateral knee and grasps OVER the contralateral knee
- Other hand grasps the ipsilateral ankle applying internal and external rotation as the hip reduces
- Waddell Technique
- Modified from Allis Maneuver and Bigelow Maneuever for less back strain for examiner
- Patient lies supine with ipsilateral hip flexed to 60-90 degrees and knee flexed to 90 degrees
- Assistant stabilizes Pelvis by applying downward pressure
- Examiner squats on bed
- Examiner places one hand on the assistant's Shoulder for support
- Examiner hooks their Forearm under the patient's ipsilateral knee and grasps their own knee
- Patient's ipsilateral leg is between the examiner's knees
- Examiner applies longitudinal traction by leaning backwards
- Examiner may also apply internal and external rotation to the hip as it reduces
- Allis Maneuver
- Anterior Hip Reduction Techniques
- Allis Leg Extension Method
- Patient supine
- Assistant stabilizes Pelvis against bed
- Examiner grasps ipsilateral knee and applies longitudinal traction, in-line with the hip
- May also apply external rotation or hip flexion
- Reverse Bigelow Maneuver
- Patient supine
- Examiner
- One hand grasps the ipsilateral ankle
- Other hand grasps behind the ipsilateral knee
- Examiner applies inline, longitudinal traction
- Hip adduction, extension, internal or external rotation may be added
- Allis Leg Extension Method
- Either Anterior or Posterior Reduction
- Lateral Traction Technique
- Patient supine with knee extended
- Assistant wraps hands or a sheet around the upper inner, ipsilateral thigh
- Assistant pulls laterally
- Examiner grasps lower leg and applies longitudinal traction in line with hip
- Internal rotation may assist reduction as the hip begins to reduce
- Stimson Gravity Method
- Patient prone and lower legs hang over the edge of the bed with hip and knee flexed to 90 degrees
- Assistant applies downward pressure on Sacrum
- Examiner grasps the ipsilateral lower leg (below knee) and applies downward pressure
- Consider gentle internal and external rotation to aid reduction
- Lateral Traction Technique
- Resources
- Hip Reduction Trauma (Kelly Barringer, MD)
XIV. Management: Post-Reduction Restrictions after Traumatic Hip Dislocation
- Protected weight bearing (or toe touch only weight bearing) for 4-6 weeks
- 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
- Hip strengthening Exercises
- Delay return to sport for 6-12 weeks
XV. Management: Orthopedic Consultation Indications
- Emergent Consultation Indications
- Proximal Femur Fracture
- Acetabular Fracture with instability (operative fixation indication)
- Posterior wall fragment >33% OR
- Positive intraoperative fluoroscopic stress views
- Hip that cannot be reduced with maneuvers above while under adequate Procedural Sedation
- Prolonged Hip Dislocation
- Safe Procedural Sedation is not possible due to patient's condition
- Status-post total hip arthroplasty (THA) concerns
- THA within the last 6 weeks (Risk related to unhealed surgical incision)
- Previously reconstructed acetabulum
- Peri-prosthetic Fracture or broken implant
- Grossly loose femoral implant or cup
- Complex THA implants (e.g. constrained liners, dual-mobility femoral head implant)
- Other Urgent Referral Indications
- Marginal Impaction
- Subchondral bone rotation and impaction into the underlying cancellous bone
- Requires elevation and bone grafting
- Risk of Hip Osteoarthritis if not addressed early
- Intraarticular debris within Hip Joint
- Requires skeletal traction to prevent chondral injury until open repair
- Intraprosthetic Dislocation
- Large, polyethylene femoral head separates from the smaller femoral head
- Requires early revision surgery to prevent instability
- Identified on post-reduction XRay
- Femoral head will appear off center within acetabulum
- Adjacent soft tissue will demonstrate a halo representing the separated polyethylene ring
- Marginal Impaction
- Routine referral
- Status-post Total Hip Arthroplasty (notify orthopedics of dislocation)
XVI. Complications: Traumatic, Native Hip Dislocations
-
Hip Avascular Necrosis
- Onset within 2 years of injury
- Increased risk if delayed hip relocation due to disruption of arterial supply
- Risk increases from 4.8% if reduced in under 6 hours to nearly 53% if delayed >6 hours
- Post-Traumatic Arthritis
- Prevalence 24% after Traumatic Hip Dislocation (esp. in heavy manual labor)
- Sciatic Nerve Injury (esp. Peroneal Nerve)
- Surgical exploration is indicated for sciatic nerve distrubution Neuropathy persisting after relocation
- References
XVII. Resources
- Hip Dislocation (Core EM)
- Hip Reduction Maneuvers (Waddell, et. al.)
XVIII. 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]