Hip pain is extremely severe following hip joint dislocation or hip dislocation. Traumatic injury involving hip joint often causes dislocation of the hip joint. Hip dislocation is common following total hip joint replacement surgery and auto accident. Hip dislocation is complete separation of head of the femur from acetabulum. Impact of trauma over hip joint or mismatch of ball and socket prosthesis following total hip joint replacement surgery causes head of the femur to get dislodged from its socket acetabulum (socket of pelvic bone). Partial hip dislocation is also known as subluxation. Subluxation is rare and mostly associated with partial fracture of acetabulum. Multi-axial movement of normal hip joint involves flexion, extension, abduction, adduction, diagonal rotation and pelvic rotation.
Hip joint dislocation associated with severe hip pain is a medical emergency and treatment should be provided within 6 to 8 hours to prevent avascular necrosis. Lack of blood supply to dislocated hip and acetabulum bone may cause avascular necrosis resulting in intractable hip pain.
Usually hip dislocation occurs when the head of the femur gets dislodged from its acetabular socket. In most patients, the femur shifts out of its socket and lies posterior to acetabulum and pelvis (posterior dislocation). The hip pain become excruciating with any passive or active movement of injured lower leg. Hip dislocation may be associated with nerve injury and significant blood loss causing massive blood clot compressing nerve resulting in severe throbbing hip pain.
Causes of Hip Joint Dislocation Resulting In Severe Hip Pain
Causes of Traumatic Hip Joint Dislocation
- Automobile Accident
- Work Accident
- Violent Injury Such As Falls or Blows to the Hip.
Causes of Post Surgical Hip Joint Dislocation
- Total Hip Replacement Surgery- Following surgery 15% of the patients develop severe hip pain associated with hip joint dislocation within 24 weeks or 6 months.
- Surgery involves removal of head and neck of femur and insertion of artificial head and neck over femur bone. Similarly acetabular socket is trimmed and resurfaced. Appropriate size of head of femur must match the semicircular socket of acetabulum. Larger or smaller size of acetabular compared to head of the femur can cause dislocation and severe hip pain.
Types of Hip Joint Dislocation
- Congenital Hip Dislocation- Congenital dislocation of the hip is caused by dysplasia of the head of the femur and/or acetabular socket.
- Seen In Newborn or young children.
- Common In Girls
- Early Detection Is Important For Close Reduction And Conservative Treatment With Few Weeks Of Traction.
- Waddling Gait- If bilateral hip dislocation is not treated, waddling gait is observed once child begins to walk. Unilateral untreated hip joint dislocation may be associated with limping while walking.
- Acquired Hip Dislocations-
- Anterior Dislocation- 8% of hip dislocations are anterior dislocation. Anterior dislocation may cause femoral nerve and femoral artery injury. Laceration or tear of femoral artery may cause profuse bleeding and hematoma in front of hip joint. Massive hematoma and pressure on femoral nerve causes severe hip pain.
- Posterior Dislocation- Ninety percent of dislocations are posterior dislocation. Posterior dislocation often causes sciatic nerve injury and severe hip pain.
- Central Dislocation- Central dislocation is rare. Central dislocation is often associated with fracture of the acetabulum and may need surgical repair.
- Recurrent Dislocation- Causes ligament injuries.
Symptoms of Hip Joint Dislocation
- Hip Pain- Severe intractable hip pain is felt immediately following hip dislocation. Pain is increased with activities.
- Inability to Move Leg- Patient is unable to move the injured limb.
- Numbness and Tingling- Symptoms such as tingling and numbness is observed following sciatic or femoral nerve injury.
- Muscle Weakness- Nerve injury causes motor nerve damage and paralysis of the muscles in affected leg.
- Clicking Sound of Hip Joint- Seen in juvenile congenital hip dislocation with flexion, extension and lateral rotation.
Signs of Hip Joint Dislocation
- Short Injured Leg-On inspection, injured leg seems to be shorter than normal leg
- Position of the Leg with Hip Dislocation- The leg is short and lies in abducted or adducted position either internally or externally rotated.
- Fractured Femur- Posterior hip dislocation is seen in 90% of the cases. Posterior hip dislocation may be associated with fracture of neck of femur and acetabulum.
- Sensory Nerve Injury- Anterior hip joint dislocation is seen in 20% of cases. Anterior hip dislocation is associated with injury of femoral nerve resulting in tingling and numbness of the thigh and knee joint.
- Motor Nerve Injury- Femoral nerve injury causes paralysis of muscles. Muscles that receive motor nerve from femoral nerves are paralyzed following femoral nerve injury.
- Inability to walk or ambulate.
Diagnosis and Investigation for Hip Joint Dislocation
- CT Scan
Treatment For Hip Joint Dislocation
Initial Treatment For Hip Joint Dislocation Causing Hip Pain
- Analgesics for Treating Hip Pain
- Pain is treated with NSAIDs such as Motrin, Naproxen and Celebrex.
- Opioids- Severe hip pain following hip dislocation may not respond to NSAIDs and may need to be treated with antibiotics.
- Close Reduction of Hip Dislocation
- Close reduction is attempted only when X-ray and MRI suggest hip dislocation is not associated with fracture of femur or acetabulum.
- Non-Surgical Close Reduction of Dislocated Hip Joint Neurological examination is performed once hip joint dislocation is diagnosed following X-Ray and MRI study. Hip joint dislocation causes sciatic nerve injury in 20% of cases. If sciatic nerve is intact then hip joint reduction is tried under General Anesthesia.
- "Allis' technique" is the safest and easiest method of reduction of hip joint dislocation. Procedure is performed under anesthesia. Leg is pulled away from hip joint while assistant is holding the pelvis and attempts to flex at hip joint followed by adduction and external rotation to bring the leg in normal anatomical positions.
Conservative Treatment For Hip Joint Dislocation
- Intravenous Fluid- If Necessary.
- Vitamin Supplement.
Specific Treatment For Hip Joint Dislocation
Hip Pain Due To Hip Joint Dislocation-
- NSAIDs- Motrin, Naproxen and Celebrex
- Opioids- Morphine, Oxycodone and Hydrocodone.
- Antidepressant Analgesics- Prescribed to treat neuropathic hip pain following hip dislocation and pain not responding to opioids. e.g. Cymbalta and Elavil.
- Antiepileptic Analgesics- Is an alternative treatment to antidepressant analgesics for neuropathic hip joint pain. Ex: Neurontin and Lyrica.
Rehabilitation Following Hip Dislocation Surgery
Rehabilitation for First 48 to 72 Hours
- Inpatient admission in rehab facility for 2 to 3 days.
- Training for Safe Ambulation-
- Training to get in and out of the bed.
- Training to use cane, walker or wheelchair for ambulation.
- Inpatient Physical Therapy-
- Goal- Improve range of motion.
- Joint and muscle strengthening.
Extended Rehabilitation after 48 to 72 Hours
- Physical Therapy- At home or nursing care.
- Occupational Therapy- Patient is taught and supervised for performance of following activities:
- Toilet Functions
Interventional Therapy For Hip Joint Dislocation
- Corticosteroid injection of hip joint, trigger point and muscles.
Surgical Options For Hip Joint Dislocation
- Arthroscopy- Diagnostic Hip Arthroscopy
- Open Reduction- Surgical treatment is indicated if conservative treatment and close nonsurgical hip reduction is failed. Surgery is also performed as soon as possible if sciatic nerve injury is suspected.
- Joint Exploration-Surgery is also indicated if bone or cartilage fragments are observed in the hip joint following injury or after close reduction.
Watch How Hip Joint Diagnostic Arthroscopy Is Performed To Know The Cause of Hip Pain
Open Reduction: For Treating Hip Joint Dislocation
- Approach- Posterior approach is preferred since rate of avascular necrosis is relative low as compared to the anterior approach.
- Screw and Plates- Use to repair a section of fractured bone.
- Insertion of Rods- To repair broken shaft of femur.
- Partial Replacement- Replacement of head and neck of femur within intact sockets.
- Total Hip Joint Replacement- Head, neck and upper 1/3rd of femur is replaced. Socket is replaced with artificial metal prosthesis.
Prognosis For Hip Joint Dislocation
- Avascular Necrosis is prevented if treatment is provided within 6 hours following dislocation of hip joint.
- Early Arthritis is seen following completion of treatments of hip joint dislocation.
Complications Following Hip Joint Dislocation Causing Severe Hip Pain
Following Are the Common Complication Observed In All Type of Hip Joint Dislocations-
- Hip Pain
- Tingling and Numbness of Injured Leg.
- Weakness of Injured Leg.
- Avascular Necrosis.
- Secondary Osteoarthritis.
- Myositis Ossificans
- Postop Immobilization may cause deep vein thrombosis, pulmonary embolus and pneumonia.
Posterior Hip Dislocation-
- Sciatic Nerve Injury
- Transverse or Posterior Rim Fracture.
Anterior Hip Dislocation
- Femoral Artery Injury
- Femoral Nerve Injury
- Severe Hemorrhage
Central Hip Dislocation-Fracture of Capsular Rim.
Hip Joint Ligamental Injuries All or One of the Five Ligaments are Likely to Be Injured
- Iliofemoral Ligament
- Teres Ligament
- Pubofemoral Ligament
- Ischiofemoral Ligament
- Ona Orbicularis Ligament