Hip Arthroscopy - Knee & Sports

Introduction
- Overview
  - increasingly common procedure as advances in technology and familiarity expands
  - technically difficult procedure due to deep location of hip joint and high congruity (as compared to knee and shoulder)
    
    significant learning curve
- Epidemiology
  - incidence
    
    250% increase in hip arthroscopies performed in US from 2007 to 2011
- Indications
  - intra-articular pathology
    
    femoroacetabular impingement lesions
    
    labral tears
    
    diagnosis and staging of AVN
    
    loose bodies
    
    chondral defects
    
    ligamentum teres injury
    
    synovial disease
    
    septic arthritis
  - extra-articular pathology
    
    AIIS subspine impingement
    
    capsular tears or instability
    
    iliopsoas tendon pathology
    
    gluteal tears
    
    trochanteric bursal debridement
    
    ischiofemoral impingement
    
    deep gluteal syndrome
    
    piriformis debridement/release
    
    proximal hamstring tears
- Contraindications
  - advanced DJD
  - hip ankylosis
  - severe dysplasia
  - joint contracture
  - severe osteoporotic bone
  - significant protrusio acetabuli
- Prognosis
  - lower morbidity than open arthrotomy with expeditious post-operative course

Setup, Positioning, and Joint access
- Setup
  - dedicated hip arthroscopy instruments required
    
    70-degree arthroscope
    
    long cannulas and guides
    
    flexible instrumentation
  - fluoroscopy positioned so both fluoroscopic and arthroscopic towers visible
- Positioning
  - may be done supine or in lateral decubitus position
    
    regular fracture traction table or commercially made tables/attachments available
  - perineal post, if used, must be well padded
  - traction placed through operative leg to distract joint for safe entry
    
    often requires around 50 pounds of traction
    
    bed may be placed in Trendelenburg to lessen force required
- Access
  - needle insertion at anterolateral portal site
  - spinal needle placed into hip joint (central compartment) with aid of fluoroscopy to avoid femoral head and labrum
  - can load joint with saline to distend
    
    alternatively, joint can be vented to create air arthrogram
  - guidewire, cannula, and arthroscope inserted into joint
  - subsequent portals placed under direct visualization and/or fluoroscopy
    
    portal use dictated by pathology being treated

Portals
- Anterolateral portal (AL)
  - function
    
    primary viewing portal
    
    anterolateral hip joint instrumentation
  - location and technique
    
    located 2 cm anterior and 2 cm superior to anterosuperior border of greater trochanter
    
    established first under fluoroscopic guidance
  - structures at risks
    
    superior gluteal nerve
- Anterior portal (AP)
  - function
    
    central compartment visualization and instrumentation
  - location and technique
    
    often second portal created
    
    starting point originally described at intersection between superior ridge of greater trochanter and line drawn longitudinally from ASIS
    
    subsequently moved variable distance lateral to this line to avoid lateral femoral cutaneous nerve
    
    flexion and internal rotation of hip loosens capsule and may assist scope insertion
    
    interportal capsulotomy made connecting anterior portal to anterolateral portal
    
    iliofemoral ligament fibers cut
  - structures at risk
    
    lateral femoral cutaneous nerve
    
    ascending branches of lateral femoral circumflex artery
    
    femoral neurovascular bundle
- Distal anterolateral portal (DALA)
  - function
    
    provides access to the peripheral compartment in the region of the femoral neck
  - location and technique
    
    starting point 3 to 5 cm distal to the anterolateral portal
    
    traction is removed and the hip is placed in either neutral flexion and extension or in 45 degrees of flexion to relax the anterior capsule
    
    fluoroscopy and direct arthroscopic visualization is used to guide portal placement
  - structures at risk
    
    ascending branch of lateral femoral circumflex artery
- Mid-anterior portal (MAP)
  - functions
    
    imilar to anterior portal
  - location and technique
    
    various different portals described
    
    all made lateral to anterior portal and medial the anterolateral portals
- Posterolateral portal (PL)
  - function
    
    posterior hip joint access and instrumentation
  - location and technique
    
    located 1 cm posterior and 1 cm proximal to the posterosuperior tip of the greater trochanter
    
    leg in neutral rotation
  - structures at risk
    
    sciatic nerve

Compartments
- Central compartment
  - consists of
    
    acetabular fossa and femoral head articular surfaces
    
    ligamentum teres
    
    acetabular rim and labrum
    
    AIIS and capsule
  - requires traction for access and instrumentation
- Peripheral compartment
  - portion of hip joint lateral to the labrum
  - no traction required
  - consists of
    
    femoral head-neck junction
    
    iliopsoas tendon
    
    zona orbicularis
    
    landmark for the iliopsoas tendon
    
    medial synovial fold
- Lateral compartment
  - trochanteric and peri-trochanteric area
  - no traction required
  - consists of
    
    IT band and bursa
    
    gluteus medius/minimus tendons
- Deep gluteal space
  - extra-articular posterior hip space
  - no traction required
  - consists of
    
    piriformis and sciatic nerve
    
    hamstring origin at ischial tuberosity

Rehabilitation
- Rehab protocols vary by procedure and surgeon
  - physical therapist involvement prior to procedure to discuss expectations
  - immediate post-operative full or brief protected weight-bearing
    
    foot-flat partial weight-bearing with progression to full weight bearing
  - early range of motion
  - strengthening is started after full ROM is achieved
    
    iliopsoas tendinitis common
- Return to full activity
  - earlier reports of faster recovery following arthroscopic procedures compared with open

Complications
- Chondrolabral injuries
  - iatrogenic chondral injuries most commonly reported complication
  - due to scope or instrumentation placement
  - avoid by
    
    instrumentation under direct visualization
- Hip instability
  - iatrogenic hip instability due to capsular insufficiency
  - risk factors
    
    imprecise capsulotomy
    
    lack of capsular closure
  - avoided with
    
    careful initial capsulotomy
    
    capsular closure or plication
- Neurovascular injury
  - traction related
    
    associated with amount of traction force required
    
    pudendal nerve injury
    
    most common overall neurovascular complication
    
    neuropraxia or compression injury
    
    due to perineal post for traction
    
    avoided with
    
    post-less surgery
    
    peroneal nerve injury
    
    traction or compressive neuropraxia
    
    due to traction or compression from ill-fitting boot
    
    avoided with
    
    intermittent release of traction
    
    total traction time under 2 hours
    
    adequate muscle paralysis (requires less traction force)
  - portal related
    
    superior gluteal nerve
    
    anterolateral portal
    
    sciatic nerve
    
    posterolateral portal
    
    increased risk with external rotation of hip
    
    lateral femoral cutaneous nerve
    
    anterior portal
    
    avoid any instrumentation medial to ASIS
    
    ascending branch of lateral femoral circumflex artery
    
    distal anterolateral portal
- Fluid extravasation
  - risk factors
    
    prolonged surgical time
    
    high pump pressure
  - prevention
    
    low-pressure pump settings
    
    iliopsoas tenotomy/lengthening performed last
- Heterotopic ossification
  - prevention
    
    routine NSAIDs post-operatively
- Conversion to total hip arthroplasty
  - risk factors
    
    obesity
    
    age greater than 60
    
    female gender
    
    tobacco use
    
    low case volume surgeon
    
    pre-existing hip osteoarthritis