Arthrodesis Conversion

Indications

 

Severe LBP 

- most common indication

 

Ipsilateral knee pain

- less beneficial

 

Malposition

- especially abduction

 

Contraindications

 

Absent abductor mechanism

Flail

Active infection

Insufficient bone stock

 

Examination

 

LLD

 

Assessment abductor function

 

1.  Palpation whilst asking patient to contract

2.  MRI

 

Issues

 

1.  Difficulty prepping & draping

 

2.  Exposure

- identify sciatic nerve

- perform GT osteotomy

- may require adductor & psoas tenotomy

 

3.  LLD

- maximum 4cm lengthening 

- use ASIS pin as LLD guide

 

Xrays

 

Hip Fusion 1Hip Fusion THR 1

 

Hip Fusion 2Hip Fusion THR 2

 

Hip Fusion 4Hip Fusion THR 4

 

Hip Fusion 5HIp Fusion THR 5

 

Results

 

Joshi et al JBJS Am 2002

- 208 hips converted at average 51 years

- average follow up 9 years

- 83% good to excellent function

- 96% 10 year survival

- 15 nerve palsies

 

Complications

 

Loosening

Infection

Sciatic nerve palsy

HO

Residual LLD

Poor abductor function