BASIC ARTHROPLASTY WORKSHOP
ARTHROCON
HIP SURGICAL ANATOMY & APPROCHES
OP LAKHWANI
Associate Professor, Orthopedics Surgery,
ESIC – Postgraduate Institute Of Medical Sciences & Research, ESI Hospital, New Delhi
SURGICAL ANATOMY
HIP Ball & socket joint
6 degree movements
Hip inclined plane shearing forces.
Cement – strong compression than shearing forces
Femur > Acetabulum wear
DISSECTION
Superior and
inferior Gluteal
Nerve
ACETABULUM
Anterior - iliopubic eminence
Superior - strong thick
Posterior - Stability
Medial - Tear drop
ilioischial line
Inferior - deficient, TAL
ACETABULUM EXPOSORE
360 degree exposureSuperior
large smooth Steinman pin to
retract abductor
Anterior
Iliopubic eminence place a
curved pointed retractor
translate the femur anteriorly.
Difficult exposure - check distal
insertion of the gluteus maximus
tendon on the femur and the retained
superior capsule and tendon of the
reflected proximal rectus femoris have
been adequately released.
ACETABULUM EXPOSURE
Inferior - a cobra retractor at
transverse acetabular
ligament.
Posterior - wide
Hohman- type
retractor into the
tuberosity of the
ischium. Take care
not place posterior
acetabular
wall and into the
acetabular fossa.
ACETABULUM EXPOSURE
Remove remnants of acetabular labrum,
osteophyts from the acetabular brim. Next
remove the pulvinar (fibrofatty material
medially).
avoid the ascending branch of the
obturator artery when removing the
inferior pulvinar near the transverse
acetabular ligament.
medial osteophyte is present, the pulvinar
may not visible. This means that
acetabular reaming needs to proceed
medially down to the true medial aspect of
the acetabulum.
Acetabular Fixation Safe Area
The successful total hip arthroplasty -
fixation and stability with appropriate
component positioning.
Restore center of rotation, leg length, and
offset, Inclination, Anteversion,
POSITIONING OF ACETABULUM CUP
Orientation -10 – 300 of anteversion, 40 - 500
abduction
Position – flexion deformity , lumbar lardosis – ant Pelvic tilt
Inclination - targeted to 40° ± 5°
Combined anteversioncustomized according to femur to combined
anteversion of 30° to 45° (with 5° margin of error for safe zone of 25° to 50°), lower r men with low femoral anteversion, and higher women .
Center of rotation - Reaming medially is done to the cotyloid notch which medializes the center of rotation 3 to 6 mm; removal of the lunate bone and formation of a hemisphere moves the centerof rotation cephalad to 5 mm.
Surface land marks - ASIS, iliac tubercle, Shoulder Patient positioning, Greater trochanter
Inter conlar axis patella
Positional guide
Intra-articular landmarks
orient the inferior most portion of the cup at the level of the teardrop and margin at TAL, anterior margin at level of ant wall the posterior edge of the cup at the level of the ischium.posterior superior edge may over hang mm anterior.
,
Notch Acetabular angle - lies parallel to acetabular opening hence aligning the cup along sciatic notch acetabular angle reproduces normal anteversion aligning socket towards notch add 10-15 0
additional antevesion
Cup stability – combined anteversion
anatomy of acetabulum not permit anteversion of cup
beyond 30°. Abn anteversion , modular stem, or
cementing .
limits 25° to 45° anterior dislocations if more than 50°
combined anteversion
lower in men because femoral anteversion.7° in women in
our study.
To accomplish the combined anteversion requires femoral
preparation first so the cup can be adjusted to the stem.
The combined anteversion test assesses component
positioning With the limb in 10 adduction, the femoral head
should be coplanar with the face of the acetabulum. when
the limb is internally rotated.
FEMORAL PREPERATION - LIMB LENGTH
Measure length before dislocation
and compare after
Offset
Cut – level , Direction, anteversion
Anteversionpatella, transcondylar
axis
Measuring the distance from the lesser
trochanter to the center of the femoral
head and reproducing this dimension
post-arthroplasty will help to minimize
leg length discrepancies.
Leg length
The lesser trochanter should not impinge on the ischium in full extension and should be one fingerbreadth above the tip of the ischium for correct leg length.
In external rotation and abduction, the metal neck should not impinge on the cup nor the greater trochanter on the posterior ilium. In flexion and internal rotation, the metal
neck should not impinge on the anterior-superior cup or the greater trochanter on the anterior ilium.
Several tests are available to assess the quality of the arthroplasty including the combined anteversiontest, the shuck test, the Ober test, and the range-of-motion test.
Failure to restore component offset may result in instability, limp, and excessive wear. Increasing the offset may lead to pain, stiffness, and functional leg lengthening due to abduction contracture.
SURGICAL APPROACEHS
Surgeon driven
Expertise
Training
Personal philosophy
95% case primary hip can be operated with one approach hence said master the one approach
Situation - Altered anatomy
Previous surgery
Pt related factors
Preference one over other
Internervous Intermuscular plane Least interfering Neurovacular structure and tissue trauma.
Classic ilitibial band Gluteus med Key Muscle, Essentially lateral differ only in so far as they may be slightly anterior or posterior to the lateral plane. The anatomical structure which determines the question is theGlutus med tensor fascia Approach in front of this muscle antero-lateral: if behind, then postelo-late'al.
Trans trocha main door Charnley
AnteroL
PosteroL
SURGICAL APPROACEHS
Postero lateral Approach
POSITION - lateral decubitus
INSCISION
advancing anteriorly moore to gibson.
Posterior border of the greater trochanter,
and extends proximally from the level of the
vastus tubercle for 10 cm cephalad.
STEPS
Gluteus maximus incised 6 to 8 cm along
the posterior border greater trochanter.
external rotators and the posterior capsule
with the leg in internal rotation as a single
flap just proximal to the quadratus femoris
In flexible hips, the Piriformis tendon+/-
preserved and an L-shaped incision one arm
parallel to the piriformis tendon.
The hip is dislocated third incision is of the
inferior medial capsule, which is incised
from the anterior femur to the acetabulum
through the transverse acetabular ligament.
Postero lateral Approach…. Decrease dislocation – tagging before
release External rotator repair
Larger head
Adv – excellent view acetabulum and femur, risk of sciatic nerve, dislocation – post soft tissue repair - Transosseusnonabsorbable suture to repair the anterior released fiber of G medius,
easier to make these drill holes prior to reducing the hip
advantage of dependent drainage, extensile
Avoid abductor damage Ext rotator release – dislocation , Sciatic nerve
Tight hips may require 1 cms more release of G medius at anterior superior corner of GT.
difficult dislocation require ITB release and allow to slip posterior to GT.
Ant Lateral ApproachPOSITION - Supine/ LateralINCISION - Centered over greater anterior
aspect of Greater Trochanter.STEPS
-Split ITB distally and G.Max proximally.- Exposing – Vastus lateralis and G medius- Idetify position of head , Tip of greater
trochanter , Slit Vastus lateralis and G.Mediusat anterior 1/3 maintain continuty of anterior sleeve
Differ in manner and effect of releasing Gluteus medius and vastus lateralis insertion and protection of Superior Gluteal nerve and vessels.
Flexible hip, Less risk of avn head preserving surgery Limitation – superior gluteal nerve and branches , imited posterior collumn access, ant dislocation
Trochanter overhang – varus positioning of implant
Safe limit area
Surgical Approaches
Trans troch
Approach Dislocation HO Limp
PosterL ++ + +
Antero L + ++ ++
Trans troch + + +
STABILITY CHECK
Assess component stability. Examine the hip at: 90 degrees of hip flexion-simulating sitting;
flexion, adduction and internal rotation simulating the fetal sleeping position; and
in extension, abduction and external rotation,
assessing for any evidence of anterior instability.
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