FAI

1. By
Dr Salihi Abdulmalik
National Orthopaedic Hospital-Dala, Kano
12th December, 2020

2.  Proximal femur abuts acetabulum with range
of motion
 There is reduced ROM of the hip due to
uneven surfaces of the head of femur or
acetabulum or both
 Common cause of early onset hip dysfunction
and secondary osteoarthritis

4.  Acetabulum
◦ 45 degrees caudally
◦ 15 degrees anteriorly
◦ Allows 170 degrees coverage for the femoral head
 Femoral head
◦ inclines at 125 degrees
◦ Anteversion of 15 degrees

5.  Ball and socket joint
 Covered by hyaline cartilage
 Minimal gliding resistance even during peak
loading with good ROM
 ROM
◦ Head-neck ratio
◦ Size of the head
◦ Acetabular socket orientation
◦ Proximal femur orientation

6.  Pincer
 Cam
 Mixed

7.  Acetabular based disorder with
◦ Global over coverage of the femoral head (coxa
profunda or protrusio)
◦ Local over coverage of the femoral head anterioly
by a retroverted acetabulum or anteriosuperior
acetabular overhang
 Femoral head makes contact with the
acetabulum

8.  Labral lesion occurs first and subsequent
articualr cartilage
 Labrum is crushed causing intrasubstance
tears and sometimes para labaral cysts
 Healing of labrum forms an ossified rim
which further worsens acetabular coverage
 Increased shearing forces mostly in the
posterior part of the joint during medial
rotation

10.  Proximal femoral disorder
◦ Bony bump at the head neck junction (aspherical
femoral head
◦ Decrease head-neck ratio
◦ Femoral neck retroversion
◦ Decrease femoral head offset

12.  Pincer/CAM

14.  Mostly unknown
 Congenital
◦ Retroversion
 Acquired
◦ SCFE
◦ Perthes disease
◦ Post femoral/acetabular osteotomy
◦ Post traumatic - #NOF
◦ ? Rigorous physical activity during skeletal
development

15.  Groin pain
◦ Excessive demand
◦ Prolonged sitting
 Limited motion
 Difficulty sitting

16.  Antalgic gait
 Externally rotated limb-SCFE
 Limited hip flexion (<90 degrees) with
internal rotation (<5 degrees)
 Anterior impingement test (flexion,
adduction, internal rotation) elicits pain

17.  Typical patient with pincer
◦ Woman
◦ 30-40 years
◦ Pain can be marked from labral injury
◦ Cartilage damage may be moderate

18.  Typical CAM
◦ Male
◦ 20-30 years
◦ Muscular and athletic
◦ Pain less dramatic
◦ Substantial cartilage damage

19.  PINCER
 Pelvic AP
◦ Pincer
 Cross over sign
 Posterior wall sign
 Cross table lateral
◦ Anterior lateral abnormalities

22.  Acetabular fossa
medial to ilioischial
line

24.  CAM
◦ Cross leg lateral view
◦ Circle drawn over femoral head should show
smooth contour, any lesion outside indicate CAM
lesion
◦ Measure alpha angle
 normal is 42 degrees
 >50.5 degrees is diagnostic
◦

26.  1st line – center of
femoral head and
center of femoral
neck
 2nd line – center of
femoral head to the
point on the
anterolateral head-
neck junction where
prominence begins

27.  CT scan
 MRI
◦ Labral tears
◦ Paralabral cysts
◦ Articular cartilage defects
◦ Ossification of acetabular rim
◦ Loss of spherity of femoral head due to fibrocystic
changes

28.  Non operative
◦ Indications
 Minimally symptomatic patients
 No mechanical symptoms
◦ Physical therapy
◦ Restriction of athletic activities
◦ NSAIDS
◦ Benefits questionable
◦ Delays surgical correction
◦ Premature OA

29.  Surgical
◦ Periacetabular osteotomy
 Indication:
 structural deformity of acetabulum with poor coverage of
femoral head
 Retroversion
 Coxa profunda
 Technique: osteotomy and fixation

30.  Open surgical hip dislocation and trimming of
CAM and pincer lesions
◦ Indications
 Preserved articular cartilage
 Correctable deformity
 Reasonable expectations
◦ Contraindications
 >55 years
 Morbid obesity
 Advanced joint disease

31. ◦ THR
 Age >60 years with end stage hip
◦ Correction by arthroscopy

32.  Femoral neck fracture
 Heterotropc ossification
 Failure to preserve