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
Contra-indications
- 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 risk
  - 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)
- function
  - similar 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