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Total Hip
Arthroplasty
HISTORY OF HIP
REPLACEMENT SURGERY
Deformed and ankylosed joints surfaces were
contoured with Biological material e.g. Fascia latagrafts as interpositional layer to resurface the joint
and allow movement in UK an Europe in early 20th
century.
1912- Jones used gold foil as inter-
positional layer
1923- Smith-Petrson introduced
“mould arthroplasy”
Later- Backelite and Celluloid
derivatives
1937- Vitallium implants
Professor John Charnley
(1911-1982)
A British Orthopedician, Pioneer of modern hip replacement
Arthroplasty.
Developed the techniques of THR in 1960s.
APPLIED BIOMECHANICS
STRESS TRANSFER TO BONE
IMPORTANCE OF QUALITY OF BONE-
APPROPIATE IMPLANT
OPTIMAL METHOD OF FIXATION
RESPONSE OF BONE TO IMPLANT
ULTIMATE SUCCESS OF ARTHROPLASTY
RADIOGRAPHIC CATEGORISATION
BY DORR ET ALTYPE A
THICK CORTEX AND CANAL
DIMENSION
LARGE POSTERIOR CORTEX-LAT
VIEW
CHAMPAGNE FLUTE
APPEARANCE
MEN AND YOUNGER PATIENTS
GOOD FIXATION IN BOTH
CEMENTED AND CEMENTLESS
SOME BONE LOSS
SHAPE IS MAINTAINED
IMPLANT FIXATION IS NOT
A PROBLEM
TYPE B
TYPE C
MUCH OF THE CORTEX
LOST FROM MEDIAL AND
POSTERIOR CORTX
IM CANAL IS WIDE
LESS FAVORABLE FOR
IMPLANT FIXATION
COMPARISON
STRESS TRANSFER IS DESIRABLE
LESS MODULUS OF ELASTICITY = MORE ELASTIC
=LESS DIAMETER
MORE STRESS TRANSFER TO BONE
PROXIMAL MEDIAL CORTEX-MOST BONE LOSS
COLLAR-PREVENTS BONE LOSS
CEMENTLESS IMPLANTS ARE MORE
PHYSIOLOGICAL
INDICATIONS OF THR
1. Arthritis : RheumatoidJuvenile rheumatoid (Still disease)Ankylosing spondylitis
2. Degenerative joint disease :: Primary: Secondary : Slipped capital femoral epiphysis
Congenital dislocation or dysplasia of hipCoxa plana (Legg-Calvé-Perthes disease)Paget diseaseTraumatic (Fracture/ dislocations)
Hemophilia
INDICATIONS OF THR
Osteonecrosis : Post fracture or Post dislocationIdiopathic
Slipped capital femoral epiphysis
Hemoglobinopathies
Renal diseaseSteroid induced
AlcoholismCaisson disease
LupusGaucher disease
4. Nonunion following # NOF
5. Femoral neck fractures and trochanteric fractures with head involvement
INDICATIONS OF THR
6. Pyogenic arthritis or osteomyelitis : HematogenousPostoperative
7. Tuberculosis8. Congenital subluxation or dislocation9. Hip fusion and pseudarthrosis10. Failed reconstruction following: Osteotomy
Cup arthroplastyFemoral head
prosthesisGirdlestone
procedureTotal hip replacementResurfacing
arthroplasty
11. Bone tumor involving proximal femur or acetabulum
12. Hereditary disorders (e.g., achondroplasia)
TOTAL HIP
COMPONENTS AND
DESIGNS
Total Hip
Components
1.Femoral Components
(Head+ Neck+ Stem)
2.Acetabular Components
Goal of THR
Biomechanically
sound, stable hip joint
by restoration of
normal center of
rotation of femoral
head
The location of
center of rotation of
femoral head is
determined by
1. Vertical offset
2. Horizontal(medial) offset
3. Anterior offset
(Anteversion)
WHAT WILL HAPPEN IF THERE IS INADEQUATE
RESTORATION OF MEDIAL OFFSET?
WHAT WILL HAPPEN IF THERE IS INADEQUATE RESTORATION OF VERTICAL OFFSET
MEDIAL RESTORATION IS SIMPLY CORRECTED BY
MAKING NECK ADJUSTMENT BUT……
LIMB LENGTH INCREASES
VERSION
NORMAL FEMUR IS 10 TO 15 DEGREE ANTEVERTED.
USUALLY ACCOMPLISHED BY ROTATING THE
COMPONENT IN FEMORAL CANAL.
IN PRESS FIT FIXATION IS USED –MODULAR FEMORAL
COMPONENT IS USED.
HEAD NECK RATIO AFFECTS ROM ,IMPINGEMENT,STABILITY OF ARTICULATION.
TYPES OF FEMORAL
COMPONENTS
Cemented stems Cementless stems
porous surface
nonporous surface Specialized custom-made
CEMENTED STEMS
Most designers favour- cobalt chrome alloy
PMMA cement is the standard for
femoral component fixation
Pitfalls- Debonding, Mechanical loosening,
Extensive bone loss with fragmented cement
2. Cementless stems with porous
surface Fixation is more biological.
Material- titanium alloy/ Cobalt-Chromium alloy
Bone ingrowth into porous metal surface
Requires: a)immediate mechanical stability at
the time of surgery
b) intimate contact between porous
surface and viable host bone
So, surgical technique and instrumentation
need to be more precise than cemented
counterpart
Specialized custom-made
Specialized femoral components for replacement of variable lengthth of proximal femur. Stem can
be combined with TKR to replace entire femur
ACETABULAR
COMPONENTS
Cemented
Cementless
Constrained type
Specialized custom made
Cemented acetabular
component
PMMA spacers (3 mm)
are incorporated into
polymerizing cement,
yeilding uninterrupted
cement mantle
Satisfactory in elderly,
low demand patient,
Tumour reconstruction,
and in revision
arthroplasty.
Cementless acetabular
components
1. Porous coated for
bone-ingrowth
2. Fixation with
trans acetabular screw
Constrained acetabular
components Mechanism to lock the
prosthetic femoral head into the
polythene liner
Indications-
-Insufficient soft tissue,
-Deficient hip abductors,
-Neuromuscular disease,
-Hip with recurrent
dislocation despite well-
positioned implants.
Alternative bearings
Highly cross linked polyethylene
Metal on metal bearings
Ceramic on ceramic bearings
Metal on metal bearings
Low wear rate
High carbon cobalt chromium alloy
Diametral clearance-gap between the two
implants at the equator of articulation.
Smaller clearance produce films for lubrication
and reduced wear.
Elevated metal ions in blood that excreted
through urine.
So contraindicated in impending renal failure.
Placental transfer occur of these metal ions.
Delayed type hypersensitivity (aseptic lymphocytic vasculitis associated lesions)
Pseudotumour
Recommendation for symptomatic patients is measurement
of blood cobalt and chromium ion level and/MRI or USG.
CERAMIC ON CERAMIC
BEARINGS
ALUMINA CERAMIC IS USED.
HIGH DENSITY, HYDROPHILLIC, SMOOTHER THAN
METAL.
CERAMIC IS HARDER THAN METAL AND MORE
RESISTANT TO SCRATCHING.
LINEAR WEAR RATE IS 4000 TIME LESS THAN COBALT
CHROME ALLOY ON POLYETHYLENE.
DISADVANTAGE
IMPINGEMENT BETWEEN THE FEMORAL NECK AND
RIM OF THE CERAMIC ACETABULAR COMPONENT.
IMPLANT MALPOSITION
STRIPE WEAR
SQUEAKING
OSTEOLYSIS
OXIDIZED ZIRCONIUM
CERAMIC METAL ALLOY.
NOT SUSCEPTIBLE TO CHIPPING,FLAKING,OR
FRACTURES.
Templating of radiograph
for pre-operative planning
1. Determination
of the amount
of limb
shortening
2. Acetabular
over-lay
templating and
center marking
3. Femoral overlay
templating and
measurement of
precise size of
proximal canal
4. Selection of
appropriate
neck-length to
restore limb
length and
femoral offset
5. If no shortening present, we match the center head with previously marked center of the acetabulum
6. If a discrepancy exists, the distance between the femoral head center and acetabular center should be equal to the measured limb length discrepancy
SURGICAL
APPROACHES
POSITION OF THE
PATIENT FOR
POSTERIOR
APPROACH
POSTERIOR
APPROACH
Reaming of acetabulum
Femur is retracted anteriorly to allow clear access to acetabulum
REAMING OF
ACETABULUM
SOCKET POSITIONING
Safe and unsafe
quadrants of
acetabulum
POSTEROSUPERIOR
QUADRANT- SAFEST
FIXATION HOLES FOR
CEMENT IN ACTABULUM
ACETABULAR CEMENT
PRESSURIZER
PRECAUTIONS
FIXATION MUST BE AUGMENTED BY SCREWS OR
SPIKES.
PERIPHERAL PART OF POSTEROSUPERIOR SEGMENT ARE SAFEST.
PALPATION OF GREATER SCIATIC NOTCH IS MUST.
INTRAOPERATIVE CHANGE IN THE POSITION.
PREPARATION
OF THE FEMUR
POSITIONING OF FEMUR
FOR REAMING
Neck is cut
planned at
appropriate level
and angle by
using trial
components of
templeted size
Removal of
remining lateral
edge of femoral
neck and medial
portion of GT with
box osteotome
Reaming of
femoral canal
Hand or power
reamer must be
lateralized into
GT to maintain
neutral
alignment of
femoral canal
Femoral
broaching
Progressively larger
broaches are inserted,
lateralizing each one
to maintain neutral alignment
Femoral
component
anteversion
Calcar
planning
with
prcision
reamer
Assembly of trial
head and neck
segments
determined
from pre-
operative
templating
Canal
blocking
Retrograde
injection of
cement with
gun in early
dough phase
Cement
pressurization
Manual
cement
packing
(PALACOS cement)
HIP SHOULD BE STABLE IN
IN FULL EXTENSION WITH 40 DEGREE OF EXTERNAL
ROTATION.
IN FLEXION TO 90 DEGREE WITH ATLEAST 45 DEGREE OF INTERNAL ROTATION
WITH THE HIP FLEXED 40 DEGREE WITH ADDUCTION
AND AXIAL LOADING-
IF HIP DISLOCATE OR SUBLUXATE –USE LONGER
NECK.
WHAT IF FRACTURE
OCCUR
STOP THE INSERTION
EXPOSE THE FRACTURE
IF AN INCOMPLETE FRACTURE OCCUR WITH
EXTENSION ONLT AT THE LEVEL OF LT-ENCIRCLAGE
,REINSERT AND REASSESS THE STABILITY.
BELOW LT –LONGER STEM
GT IS # AND UNSTABLE-FIX THE GT WITH WIRES.
TROCHANTERIC
OSTEOTOMY
SURGICALS PROBLEMS
RELATIVE TO SPECIFIC HIP
DISORDER
OSTEOARTHRITIS
MC INDICATION
REMOVAL OF OSTEOPHYTES MAY BE NECESSARY.
Difficulty in delivering femoral head.
RHEUMATOID ARTHRITIS
THEY GENERALLY RECEIVES IMMUNOSUPPRESSIVE DRUGS.
IF BOTH HIP AND KNEE IS INVOLVED EQUALLY, HIP ARTHROPLASTY
SHOULD BE DONE FIRST .
OSTRONECROSIS
STAGE 1 AND 2-CORE DECOMPRESSION
,VASCULARISED GRAFT OR BY VALGUS
OSTEOTOMY
RESURFACING ARTHROPLASTY IF < 50 % OF HEAD
MOSTLY AGE GROUP IS 25 TO 45 YEARS-THR IS NOT
VERY SUCCESSFUL.
IMPROVED RESULT WITH ALUMINA CERAMIC HEAD
HIGHLY CROSSLINKED POLYETHYLENE.
DWARFISM/DYSPLASIA
NARROW CANAL
BOWING
ALTERD FEMORAL ANATOMY
PREVIOUS FEMORAL OSTEOTOMY
SHORT FEMORAL COMPONENT IS USED .
ACUTE FEMORAL NECK
FRACTURE
THR > HRA>INTERNAL FIXATION
THOSE WHO ARE LESS HEALTHY,COGNITIVELY
IMPAIRED OR REQUIRE ASSISTIVE DEVICE FOR AMBULATION ARE BETTER SUITED FOR HRA.
Post operative hip
re-dislocation can be avoided by:
Maintaining abduction using pillows
Avoiding crossing legs
Avoiding squating
Using chairs with armrest
Not bending forward past 90 degrees
Using a high-rise toilet seat if necessary
Avoiding pronation the legs
Avoiding stairs
Exercise PrescriptionEarly Stage
Exercise Prescription
- Later Stages -
COMPLICATIONS OF THR
1. Hematoma formation
2. Heterotropic ossification
3. Thromboembolism
4. Nerve injuries (sciatic, femoral, obturator or sup gluteal
nerve)
5. Vascular injuries
COMPLICATIONS OF THR
6. Limb length Discrepency
7. Dislocation and subluxation
8. Fractures of acetabulum and femur
9.Trochenteric nonunion and migration
10. Infection
11. Loosening ( Femoral and acetabular
component)
12. Osteolysis
POST OPERATIVE
X-RAY
THANK YOU