contains all the basics required for understanding THR

1. Basics of total hip
arthroplasty
DR NIMESH NEBHANI
POST GRADUATE RESIDENT
GUIDED BY : DR SANDEEP PANGAVANE
DR VASANTRAO PAWAR MEDICAL COLLEGE NASHIK MAHARASHTRA

2. Evolution
Osteotomy Arthroplasty
Interpositional Arthroplasty
Reconstructive Arthroplasty
Partial/Hemi Arthroplasty
Total Hip Arthroplasty

3. Evolution
Earliest record of hip arthroplasty – 1827
Various materials used, including Glass, Ivory, Acrylic etc
Various giants like Judet, McKee, Smith Petersen etc
tried, but were unsuccessful

4. MARIUS SMITH-
PETERSEN (1923)
Boston.
Vitallium Cup
‘Mould’
Arthroplasty
Interpositional Arthoplasty

5. OTTO E. AUFRANC
Interpositional Arthroplasty
82% success rate in
1000 cases (1957)

6. Sir John Charnley
Initially teflon socket – early failure – wear
Accidentally stumbled upon HDPE
Concept of Low Friction Arthroplasty
22.225mm head and thick
poly socket
Use of cement - 1953

7. Dr K T Dholakia
Father of Arthroplasty in India
At one time did more
Arthroplasties than all others
in India put together

8. Evolution

9. Hip Biomechanics
Centre of Hip
rotation
Abductor lever arm

10. Hip Biomechanics
Frictional torque
proportional to
head diameter
Large head
•Increased arc of motion
•Reduced impingement

12. Pre operative planning
• Introduced by muller in 1975
• Appropriate history
• Physical examination
• Radiographic evaluation
• Surgical templating

13. History and physical examination
• Surgical decisions such as implant selection , bearing type , mode of
fixation ( cemented uncemented) are based on AGE , SEX, DIAGNOSIS,
ACTIVITY LEVEL , MENTAL STATUS .
• Assessment of spine and knee performed to identify extra articular
sources of hip pain.
• True and apparent length assessed
• True – bony hip pathology
• Apparent – soft tissue contractures ( flexion , abduction ) scoliosis ,
pelvic obliquity

14. Radiographic evaluation
• Provides data on degree of offset and limb lengthening
• Anticipate potential difficulties in OR and make adjustments in
advance
• Overlengthening – sciatic palsy , abnormal gait , LBP ,instability and
aseptic loosening

15. Offsets

16. Templating
3 XRAYS TAKEN
PBH AP
AP AND LATERAL OF AFFECTED HIP

17. The AP pelvis view. The beam is centered over the
pubic symphysis and includes the proximal third of the
femur to allow for templating.

18. INLET VIEW – INCREASED
OUTLET - DECREASED

19. • AP – supine with 15 degree IR , centred over symphysis and includes
proximal third of femur
• Neutral pelvic tilt and rotation – symphysis should lie on a line
through centre of sacrum and coccyx and two obturators should
appear symmetrical

20. Lowenstein lateral view
• Positioning for a Löwenstein view. Patient is turned onto the
affected hip at least 45° with the hip flexion angle of 90° and an
internal rotation angle of 45° in a supine position and then images
of each side are taken vertically from the groin region.
• USED FOR LOCATING PROXIMAL FEMORAL ENTRY POINT IN
PIRIFORMIS FOSSA

23. CROSS TABLE LATERAL VIEW

25. BONE QUALITY AND PROX FEMUR GEOMETRY
• SINGH INDEX- OSTEOPOROSIS, BASED ON DENSITY OF TRABECULAR
BONE OF PROXIMAL FEMUR
• DORR – GEOMETRY OF PROXIMAL FEMUR CANAL

28. RADIOGRAPHIC TEMPLATING – step 1
• Determination of magnification
• By putting a coin of known size

29. Step 2- radio landmarks
The radiographic
teardrop (in green) infero medial portion of
acetabulum and is in close proximity with
cetre of hip rotation
ilioischial line or kohler’s line (in red)-
medial border od iliem to medial border of
ischium , to assess degree of protrusion
acetabuli
the superolateral margin of the acetabulum
(in blue)- degree of acetabuli coverage

30. Step 3 – determination
of LLD
Inter tear drop line

31. Step 4 – acetabular templating

32. • Digital acetabular templating. The template should be oriented to
achieve an
• abduction angle of 40°–45° in relation to the interteardrop line, with
the inferomedial
• border of the cup seated near the lateral edge of the teardrop. The
center of rotation
• of the cup is marked.

33. Step 5 – femoral templating

34. • Digital femoral templating on the anteroposterior (AP) view
radiograph. The
• template is positioned inside the femoral canal, along the longitudinal
femoral axis,
• and the center of rotation of the femoral head is marked (A). The
distances between the
• proximal corner of the lesser trochanter and the center of rotation of
the femoral head
• as well as the proposed neck cut level are also determined (B).

36. THE ACETABULAR CUP
• CEMENTED
• Metabolic bone disease ,
postirradiation , renal ca
• Aseptic loosening is side effect
•
• UNCEMENTED
• Press fit
• By under reaming 1 – 2 mm
• At times supplemental screws
• Porous surface textured with HA
coating

38. FEMORAL COMPONENT
• Two basic designs
• 1) composite beam
• 2) taper slip

40. Composite beam
• Collar
• Pre coated roughened cylindrical surface
• Cylindrical profile
• Sit up and stay prosthesis
• CHARNLEY STEM
all these for strong bond with cement

41. TAPER SLIP
• EXETER STEM
• Collarless
• Highly polished fixation surface
• Tapered profile
• Slip and slide

43. CEMENTLESS FIXATION
• Osteo integration
• Biological and dynamic fixation because of bone turnover , stable with
time
• Porous or biologically active fixation surface coated with bioactive
materials like pure titanium or ceramics i.e. hydroxyapatite
• No aseptic loosening
• Excessive hoop stress cause intra op fracture

45. Hybrid and reverse hybrid
• Hybrid – cementless acetabular component and cemented femur
• Reverse hybrid -

46. DESIGN AND ALIGNMENT OF COMPONENTS.
neck length determines limb length and offset
determines abductor lever arm

56. Articular Surface Replacement (ASR)
Pros
Bone conserving
Increased hip ROM
↓dislocation
Cons
Limited indications
Steep learning curve

57. THANK YOU