Radial Head & Neck Fractures

Radial Head Fracture

 

Mechanism

 

FOOSH

- axial load with a valgus force

 

Biomechanics

 

1.  Provides Valgus stability

- especially if MCL deficient

 

2.  Longitudinal stability

- aided by interosseous membrane

 

3.  Load Transfer

- 60% of load at elbow

- with radial head excision, load is transferred to ulno-humeral joint

- increase risk of OA

 

Hotchkiss modification of Mason Classification

 

Type I

 

Undisplaced fracture

- intra-articular displacement < 2mm

- no mechanical limit forearm rotation

- if in doubt, inject LA into radiocapitellar joint / soft spot

- ensure no mechanical block to rotation

 

Radial Head Mason 1Radial Head Fracture Mason 1

 

Type II

 

Displacement > 2mm

- motion mechanically limited

- reconstructable

 

Radial Head Fracture Type 2Radial Head Fracture Type 2 CTRadial Head Fracture Mason 2

 

Type III

 

Severely comminuted fracture of the radial head and neck

- not reconstructable

- requires excision for movement

 

Type IV

 

Associated with elbow dislocation

 

Complicated Radial Head Fracture

 

1.  Elbow Dislocation

 

2.  Essex Lopresti

 

Fracture Radial Head + Disruption DRUJ / Interosseous membrane

- dorsal dislocation of DRUJ

- ORIF / replacement radial head

- supinate DRUJ to reduce +/- TFCC repair +/- K wire

 

Surgical Options

 

1.  ORIF

 

Radial Head ORIF

 

Kocher approach

- between anconeus and ECU

- dissect muscles off capsule

- protect ulna collateral ligament under anterior edge of anconeus

- pronate forearm to protect PIN

- divide capsule in line with incision, create anterior and posterior flaps

 

Safe Zone for implants

- posterolateral portion of cartilage

- yellow and thinner

- non articulating

- 90o arc between radial styloid and lister's

 

ORIF 

- headless compression screws

 

Complications

 

AVN 

- soft tissue stripping

 

Non union 

- same reasons

- 10%

 

Results

 

Ring et al JBJS Am 2002

- results of ORIF Type III radial head

- overall 54% poor results

- good results with 2 or 3 fragments

- poor results with 4 results

  

2.  Excision

 

Indication

- elderly patient

 

Contra-indication

- MCL or interosseous membrane disrupted

 

Complications

- reduced strength

- proximal radial translation

- DRUJ instability and pain

- valgus instability elbow

- arthrosis (deceased SA, increased contact stresses)

 

3.  Replacement

 

Radial Head Replacement LateralRadial Head Replacement APRadial Head Replacement Monoblock

 

Options

 

1.  Silastic 

- less resistant to compressive forces

- can get synovitis

- good as temporary spacer

- can cut out later

 

2.  Titanium

- monoblock / modular / bipolar

 

Technique Modular Titanium Radial Head

 

Radial Head Replacement

 

Excise radial head

- insert trial broaches into neck

- small or large diameter, standard or long

- insert trial head size and thickness

- check xray

- ensure not overstuffed

- put through range

- prepare real implant on operating table

- have to insert head and neck as one piece

 

Radial Head Replacement Lysis APRadial Head Replacement Lysis Lateral

 

Results

 

Grewal JBJS Am 2006

- modular radial head

- 26 patients followed prosectively for 2 years

- no revisions

- mild OA in 19%

 

Burhart et al J Should Elbow Surg 2010

- bipolar radial head

- 17 patients followed up for between 6 and 10 years

- 2 dislocations, 8 had evidence capitellar OA

- no loosening

- 16/17 good or excellent results Mayo elbow scores

 

Complications

 

1.  Aseptic loosening

2.  Overstuffing

3.  Capitellar OA

4.  Malpositioning

 

Radial Head Poorly Positioned

 

Radial neck fracture

 

Radial Neck Fracture

 

Indications for surgery

- > 30o angulated

 

Approach

- Z incision annular ligament

- elevate supinator with arm pronated

 

Options

 

1. T plate in safe zone

- distal limit is bicipital tuberosity

- pre-contoured low profile plates

- may need to lag articular surface first

- check ROM intra-operatively

- plates often bulky and may limit ROM

 

Radial Neck Plate

 

2.  Fix with headless compression screws

- proximal to distal

- cross fracture site

 

Radial Neck Fracture ORIF Screws APRadial Neck Fracture ORIF Screws Lateral

 

3.  Retrograde Intramedullary Wire

 

4.  Radial Head Replacement