Hip fusionHip fusion 2




Young adult / children / adolescents with end stage OA

High risk of THA failure  / multiple revision surgeries


Aims of arthrodesis


Minimise shortening

Facilitate future conversion to THR




Poor bone stock

- i.e. AVN


Bilateral hip disease

- need ROM in other hip 90o in order to compensate in gait


Polyarticular disease i.e.  Rheumatoid arthritis

- likely to develop hip / knee / back OA


Degenerative disc disease

- lumbar spine ROM important to compensate in gait and ability to sit in chair


Stiff ipsilateral knee or contralateral hip




Functionally inferior to THA


Increased stress on other joints


1.  Lumbar spine pain

- most common reason for converting to THA


2.  Ipsilateral knee pain


3.  Contralateral hip pain



Difficulties with certain activities




Sitting erect in chair

Difficulty putting on shoes


Gait abnormalities


Decreased stride length / shortened stance phase

Increased energy requirements / increased oxygen consumption






Retain option of conversion to THR 

- avoid old techniques involving pelvic osteotomy

- preserve abductors




1.  Intra-articular

2.  Extra-articular

3.  Combined




Sagittal / 20° flexion

- <20° flexion - difficult to sit

- >25° flexion - difficult to walk due to LLD


Coronal / 0° adduction / abduction

- never abduction: can't walk, fall over even with 5° abduction

- too much adduction: LLD


Rotation / 15° ER 


< 2 cm LLD




Pseudarthrosis - 10% 




Extra-articular Intra-articular Combined intra-articular + anterior plate
Hip Fusion Cobra Plate Hip Fusion AP Hip Fusion 1Hip fusion 2




Surgical technique tntra-articular + anterior plate PDF




Radiolucent table with image intensifier



Smith Peterson approach

- leave abductors intact

- dislocate hip anteriorly

- between sartorius and TFL

- between G medius and Rectus femoris

- take off reflected head of rectus, remove direct head to AIIS


Remove cartilage from head & acetabulum

- cup arthroplasty instruments useful for acetabulum

- approximate raw surfaces

- pack cancellous autograft

- position hip & hold with guide-wires temporarily

- place one guide wire central in head


Check position of hip

- need to be able to do intra-operative Thomas test

- Flexion 20o / Add 0o / ER 15o



- 150° DHS / 6.5 mm cannulated screws

- through joint into thick supra-acetabular area of ilium

- supplement with additional screws as necessary


Anterior plate onto lateral aspect of iliac crest


TWB 3 months

Consider late plate removal to reduce risk peri-prosthethic fracture




Banksota et al Bone Joint J 2022

- 20 year follow up in 26 patients

- mean age at fusion 14

- Harris hip score good / excellent in 57%

- Harris hip score fair in 42%

- 20% moderate back pain

- 4% moderate knee pain


Hoekman et al PLoS One 2014

- 35 fusions with anterolateral fusion plate

- nonunion 2/35


Ipsilateral TKA with fused hip



- cannot flex hip

- impossible to flex knee when supine on bed



- knee over end of bed


Surgical technique PDF


Conversion to THA


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