THA

Arthroplasty

Indications

 

Patient > 70

 

Gjertsen et al JBJS Am 2010

- 4335 patients > 70 with displaced subcapital fractures

- minimum 1 year follow up

- 1 year mortality same in each group / 25%

- 22% reoperation in ORIF v 3% in hemiarthroplasty

- more pain / higher dissatisfaction / lower quality life in ORIF group

 

Options

 

Hemiarthroplasty

- unipolar monoblock

- unipolar modular

Perthes

Issues

 

Femur

 

Multiplanar deformity

- worsend by previous surgery

- may require osteotomy

 

Acetabulum

 

Dysplasia often present

- not as severe as in DDH

 

LLD

 

Can be significant

 

Abductors

 

Have been short for long time

- difficult to restore length

Vascular Injury

Vessels at risk

 

Extra-pelvic blood vessels

 

Femoral Artery

MCFA

LCFA

Profunda Femoris

Obturator artery

 

Intrapelvic vessels

 

External iliac artery and vein

Obturator artery

Superior and inferior gluteal

 

External Iliac Vessels

 

Anatomy

- anterior division of common iliacs / L5-S1

Technique

Cemented cup and femur via posterior approachTHR Cemented Exeter

 

Set up

- on side

- charnley supports posterior on sacrum

- anteriorly on ASIS

- patient slightly tilted backwards

- avoids cup retroversion

 

Posterior Approach

- identify short ER

Uncemented

GoalTHR Uncemented

 

Initial press fit

- implant geometry fits the cortical bone in the proximal femur

- good initial mechanical stability

 

Biological fixation for success

- good press fit

- minimal micromotion

- bony or fibrous tissue ingrowth or ongrowth

 

Management

Management Summary

 

Stage 0

 

Natural history mixed

- depends on size of lesion and diagnosis

- treat if becomes asymptomatic

- may benefit from bisphosphonates

 

Stage 1 / Normal X-ray, abnormal MRI

 

Forage: 80% G/E

Bisphosphonates

 

Stage 2 / Abnormal X-ray with cysts and sclerosis

 

A:  As for Stage I

Templating

AimTHR Templating

 

Reproduce the normal anatomical centre of rotation

Restore femoral offset 

Maintain equal leg lengths 

 

Usually template off normal hip

 

Template

 

1. LLD

2. Offset

3. Femoral component

4. Acetabular component

5. Osteotomy / femoral seating

 

Background

IssuesTHR Uncemented

 

Templating

Approach

Fixation

Bearing Surface

Head Size

Offset

 

Indications

 

Disabling hip pain

Severe functional impairment

Failed non operative management

 

Not Indicated 

 

Painless deformity