Ortho - Hip and Pelvis

What is the key principle in the initial clinical approach to hip pain?

Localize the pain first, then select physical exam tests, then order appropriate imaging.

What are the common causes of anterior or groin hip pain?

Hip osteoarthritis, femoroacetabular impingement (FAI), labral tear, and iliopsoas tendinopathy or bursitis.

What are the common causes of lateral hip pain?

Greater trochanteric pain syndrome (GTPS) and gluteus medius/minimus tendinopathy or tear.

What are the common causes of posterior hip or buttock pain?

Sacroiliac (SI) joint dysfunction, referred lumbar spine pathology, and piriformis syndrome.

What non-hip conditions can present as diffuse or referred hip pain?

Lumbar radiculopathy, inguinal or femoral hernia, and gastrointestinal or genitourinary pathology.

What is the diagnostic significance of anterior groin pain?

True intra-articular hip joint pathology most commonly presents as anterior groin pain.

What defines an antalgic gait pattern and what does it indicate?

A shortened stance phase on the affected side, indicating pain with weight-bearing.

What hip conditions typically produce an antalgic gait?

Hip osteoarthritis, hip fractures, and avascular necrosis (AVN).

What defines a Trendelenburg gait pattern?

A contralateral pelvic drop during the stance phase on the affected leg.

What underlying muscle deficit causes a Trendelenburg gait?

Hip abductor weakness, specifically in the gluteus medius and gluteus minimus muscles.

What pathologies are associated with a Trendelenburg gait?

Greater trochanteric pain syndrome, gluteus medius tears, and hip dysplasia.

What is the normal range of motion for hip flexion?

120 degrees.

What is the normal range of motion for hip extension?

20 degrees.

What is the normal range of motion for hip abduction and adduction?

Abduction is 45 degrees; adduction is 30 degrees.

What is the normal range of motion for hip internal and external rotation?

Internal rotation is 45 degrees; external rotation is 45 degrees.

What is the most sensitive physical examination finding for hip osteoarthritis?

Decreased internal rotation of the hip.

Why should hip range of motion be compared to standard normal values rather than just the contralateral side in suspected OA?

Hip osteoarthritis is frequently bilateral, so the contralateral side may also have restricted range of motion.

How is the FADDIR test performed?

The examiner passively moves the hip into Flexion, Adduction, and Internal Rotation.

What conditions are evaluated by the FADDIR test and what constitutes a positive result?

Assesses femoroacetabular impingement and labral pathology; positive if it reproduces groin pain.

How is the FABER test performed?

The examiner passively moves the hip into Flexion, Abduction, and External Rotation.

How do you differentiate hip vs SI joint pathology using the FABER test?

Anterior groin pain indicates intra-articular hip pathology, while posterior pain indicates SI joint dysfunction.

How is the Trendelenburg test performed and interpreted?

The patient stands on one leg; drop of the non-stance pelvis indicates weakness of the standing leg's hip abductors.

How is the Resisted External Derotation Test performed and what does a positive result indicate?

Resisted external rotation is applied; lateral hip pain indicates greater trochanteric pain syndrome.

How can lumbar radiculopathy mimicking hip pain be differentiated on physical exam?

L2-L4 radiculopathy pain is reproduced more with lumbar spine range of motion than with hip range of motion.

What clinical features suggest a femoral neck or pelvic stress fracture over joint OA?

Pain in runners, military personnel, or RED-S with weight-bearing; initial X-rays may be normal, requiring MRI.

How does an inguinal or femoral hernia mimic hip pathology?

Presents as groin pain but without any limitation or pain during hip range of motion.

What are red flag symptoms during an evaluation for hip pain?

Night pain, fever, unexplained weight loss, inability to bear weight, or severe pain with a normal hip exam.

What action should a clinician take if a patient has severe pain but a completely normal physical exam of the hip?

Look outside the hip joint for non-articular or referred etiologies.

Which physical examination finding has the highest positive likelihood ratio (LR+ 6.1) for hip OA?

Posterior hip pain with squatting.

Which physical exam findings have LR+ greater than 4 for diagnosing hip OA?

Groin pain on abduction/adduction (LR+ 5.7), abductor weakness (LR+ 4.5), and decreased adduction (LR+ 4.2).

Which physical exam findings are best for ruling out hip OA (lowest LR-)?

Normal passive adduction (LR- 0.25) and normal passive abduction (LR- 0.26).

Why is range of motion testing preferred over pain provocation tests when evaluating hip OA?

Decreased range of motion is more diagnostic and specific for hip OA than pain provocation alone.

What is Femoroacetabular Impingement (FAI)?

Abnormal contact between the femoral head-neck junction and the acetabular rim during motion.

What is the structural abnormality in CAM-type FAI?

An aspherical femoral head and loss of the normal femoral head-neck offset.

What is the structural abnormality in Pincer-type FAI?

Acetabular overcoverage leading to compression of the labrum.

What is the patient demographic and mechanism of injury typical for CAM impingement?

Young, athletic males involved in high-impact sports during skeletal growth.

What tissue damage occurs first in CAM impingement during hip flexion and internal rotation?

Shear forces cause articular cartilage delamination first, followed by labral tears.

How do patient age and onset differ between FAI and hip osteoarthritis?

FAI presents in younger adults with activity-related pain; OA presents in older adults with gradual, progressive pain.

How do range of motion patterns differ between FAI and advanced hip OA?

FAI presents with early isolated loss of internal rotation; OA presents with global range of motion loss.

How do X-ray findings contrast between FAI and hip OA?

FAI displays CAM or pincer bony morphology; hip OA displays joint space narrowing and osteophytes.

What are the key clinical characteristics of Pincer impingement?

Acetabular overcoverage causing labral compression, more common in females, and frequently bilateral.

What is the most common anatomical pattern seen in patients with FAI?

A mixed pattern combining both CAM and Pincer morphologies.

What is the epidemiological impact of hip osteoarthritis in the United States?

Affects >32 million Americans and is the most frequent cause of activity limitation in adults.

What are the major non-modifiable and modifiable risk factors for hip OA?

Age, female sex, genetics, obesity, and prior major joint injury.

What is the typical clinical presentation of hip OA?

Gradual onset groin pain worsening with prolonged sitting or ambulation, and pain with flexion/rotation.

What is the first-line imaging modality for suspected hip OA?

Standing anteroposterior (AP) pelvis and lateral hip radiographs.

What are the cardinal radiographic features of hip osteoarthritis?

Marginal osteophytes, joint space narrowing, subchondral sclerosis, and subchondral cysts.

When is MRI indicated in the evaluation of suspected hip OA?

When plain radiographs are normal despite persistent pain or when surgical referral is considered.

What is the overarching clinical imaging rule for persistent hip pain?

Normal X-ray + persistent hip pain = order an MRI.

What is the primary utility of CT scanning in hip and pelvis evaluation?

Characterizing complex pelvic/acetabular fractures and pre-operative planning (poor for soft tissue/early AVN).

What are the primary clinical applications of ultrasound in hip pathology?

Detecting joint effusions, evaluating tendinopathy, and guiding diagnostic or therapeutic injections.

What non-pharmacologic interventions are strongly recommended as core management for hip OA?

Exercise programs (strengthening, CV, mind-body), weight loss, and structured patient self-management education.

What benefit do walking programs offer for hip OA pain relief?

Walking programs reduce pain scores by an average of 1.4 points on a 0-10 scale.

What is the first-line pharmacologic treatment for hip OA?

Oral NSAIDs (topical NSAIDs are less effective for hip OA due to joint depth).

Why should opioids be avoided in the chronic management of hip OA?

They carry high risk of adverse events and increase postoperative complications following total hip arthroplasty.

What is the role and limitation of intra-articular corticosteroid injections in hip OA?

Provide short-term pain relief; benefits may not exceed saline injections beyond 1 to 3 months.

What are the indications for Total Hip Arthroplasty (THA)?

Advanced symptoms, structural joint damage on imaging, and failure of conservative management.

How does chronic corticosteroid therapy alter the diagnostic evaluation of hip pain?

It dramatically increases AVN risk, lowering the threshold to order early MRI if X-rays are normal.

What is the pathophysiology of Avascular Necrosis (AVN) of the femoral head?

Disruption of blood supply leads to osteocyte death, articular surface collapse, and secondary OA.

What are the main traumatic causes of femoral head AVN?

Displaced femoral neck fractures and hip dislocations.

What are the primary non-traumatic causes of femoral head AVN?

Chronic corticosteroid use (most common), excessive alcohol abuse, and blood dyscrasias.

What is the classic clinical scenario for suspecting early AVN?

A younger patient presenting with hip pain and risk factors whose plain X-rays are completely normal.

What is the diagnostic modality of choice for early detection of AVN?

Magnetic Resonance Imaging (MRI).

What classification systems are commonly used to stage AVN of the femoral head?

Ficat and Arlet classification, and the Steinberg classification.

What is the standard joint-preserving surgical intervention for early-stage (pre-collapse) AVN?

Core decompression (Steinberg stages I-III).

What adjuvant therapy combined with core decompression shows the most promise for pre-collapse AVN?

Concentrated autologous bone marrow aspirate.

What surgical procedure is required once AVN progresses to femoral head collapse?

Total Hip Arthroplasty (THA); joint-preserving procedures are no longer effective.

What are the three main anatomic locations of hip fractures?

Femoral neck (intracapsular), intertrochanteric (extracapsular), and subtrochanteric.

Why do intracapsular femoral neck fractures have a high risk of AVN and nonunion?

They disrupt the medial circumflex femoral artery, which provides the main blood supply to the femoral head.

What classification system is used for femoral neck fractures?

Garden classification (Grades I through IV).

Describe Garden I and Garden II femoral neck fractures.

Garden I is incomplete/impacted; Garden II is complete but nondisplaced. Both are considered nondisplaced.

Describe Garden III and Garden IV femoral neck fractures.

Garden III is complete with partial displacement; Garden IV is complete with full displacement.

What is the primary treatment for nondisplaced femoral neck fractures (Garden I-II)?

Internal fixation with multiple cancellous screws or a sliding hip screw, regardless of age.

According to the FAITH trial, when is a sliding hip screw preferred over cancellous screws for femoral neck fractures?

For displaced fractures, basicervical fractures, and vertically oriented fracture lines.

What is the preferred treatment for displaced femoral neck fractures in patients aged 65 and older?

Arthroplasty (hemiarthroplasty or total hip arthroplasty) due to significantly lower reoperation rates.

What is the management approach for displaced femoral neck fractures in young patients?

Urgent closed reduction and internal fixation (pinning) to attempt native joint preservation.

When is Total Hip Arthroplasty (THA) preferred over hemiarthroplasty for a displaced femoral neck fracture?

In active, healthy patients with a longer life expectancy, providing better functional outcomes.

What is the primary advantage of hemiarthroplasty over THA in frail elderly hip fracture patients?

Lower risk of postoperative dislocation.

What is the recommended post-operative weight-bearing status following hip arthroplasty for fracture?

Weight Bearing As Tolerated (WBAT).

Within what timeframe should post-operative mobilization begin after hip fracture surgery?

Within 24 hours of surgery to reduce mortality, delirium, and VTE risk.

What defines the anatomical region of an intertrochanteric fracture?

Between the intertrochanteric line and 5 cm distal to the lesser trochanter.

Why do intertrochanteric fractures have a lower risk of AVN compared to femoral neck fractures?

They occur in an extracapsular region with a rich extracapsular blood supply.

How does fixation choice differ between stable and unstable intertrochanteric fractures?

Stable fractures are managed with a sliding hip screw; unstable fractures require an intramedullary nail.

What is the standard surgical fixation for subtrochanteric hip fractures?

Intramedullary rod and nail fixation.

What is the recommended surgical timing for acute hip fractures according to AAOS guidelines?

Operative management within 24 to 48 hours.

What is the clinical impact of delaying hip fracture surgery beyond 24 hours?

Increased 30-day mortality risk.

What is the 1-year mortality risk associated with non-operative management of hip fractures?

A 4-fold increased risk of death compared to operative intervention.

When is non-operative management acceptable for a hip fracture?

In non-ambulatory, severely debilitated patients or those with end-stage terminal illness.

What advantage does regional anesthesia (spinal/epidural) offer over general anesthesia in hip fracture surgery?

Reduces the incidence of postoperative confusion/delirium (19.2% down to 9.4%).

What antibiotic prophylaxis is indicated for hip fracture surgery?

First-generation cephalosporin administered for 24 hours postoperatively.

Why is hip dislocation classified as a orthopedic emergency?

Risk of femoral head AVN increases significantly if reduction is delayed beyond 6 hours.

What direction do the majority (>90%) of traumatic hip dislocations occur?

Posterior direction.

What nerve is most vulnerable to injury during a posterior hip dislocation?

Sciatic nerve.

What imaging must be obtained prior to attempting hip dislocation reduction?

Anteroposterior (AP) pelvis and lateral hip radiographs.

When should general anesthesia be favored over conscious sedation in the ED for hip dislocation reduction?

When time since injury exceeds 6 hours (due to a high rate of conscious sedation failure).

Describe the Captain Morgan technique for hip dislocation reduction.

Provider places their knee behind the supine patient's flexed knee and applies anterior lifting force with rotation.

What is the primary physical advantage of the Captain Morgan technique?

It significantly reduces physical back strain on the clinician.

How is the Allis technique performed for posterior hip dislocation reduction?

In-line axial traction applied to the femur with the hip flexed to 90 degrees in a supine patient.

What is the unique feature of the Sitting technique for hip dislocation reduction?

It is performed with the patient seated and does not require procedural sedation.

What must be performed immediately after successful reduction of a hip dislocation?

Repeat neurovascular exam and post-reduction X-rays to confirm concentric reduction and exclude fractures.