Isolated radial head fractures

ISOLATED RADIAL HEAD FRACTURES

Kc gopalakrishnan

1.5 to 4 % of all fractures in adult

33 % of all elbow injuries

Isolated Radial head fractures

• Davidson et al- all 111 patients with entire radial head fractures had associated wrist or elbow ligamentous injury( clin orthop 1993)

• 30 – 70% associated injuries in various studies

Isolated Radial head fractures

• Rockwood and Green- assume associated injuries unless proved otherwise

Isolated Radial head fractures

• Possible to get isolated radial head fractures in elderly but rare -Rockwood and Green

Isolated Radial head fractures

• “Entire radial head fracture or displaced partial radial head fracture always associated with ligamentous injury-” Rockwood and Green

ISOLATED RADIAL HEAD FRACTURE

APPLIED ANATOMY

APPLIED ANATOMY• Radial head act as secondary

stabilizer to valgus stress, primary being MCL

• Radial head resection in presence of intact MCL does not alter valgus instability much

APPLIED ANATOMY

• PROXIMAL RADIO ULNAR JOINT

»260* arc covered with articular cartilage

»100* arc safe zone

»Pronation-supination

APPLIED ANATOMY• RADIO

CAPITELLAR JOINT

• Radial head transmits 60% of axial load of forearm to capitellum (Morrey JBJS 1988)

APPLIED ANATOMY• RADIO

CAPITELLARJOINT

This load is greatest with forearm in pronation and b/w 0-30* elbow flexion

MECHANISM OF INJURY

– Indierect injury– Axial load thru pronated forearm– Valgus injury– Posterolateral rotatory load

MECHANISM OF INJURY

MECHANISM OF INJURY

• Disruption of interroseous membrane due to acute shortening of radius producing longitudinal traction

ASSOCIATED INJURIES

ELBOW DISLOCATIONESSEX LOPRESTI

CAPITELLUM FRACTURECORONOID FRACTURE

ASSOCIATED INJURIES

MCL injury Olecranon

fraccture dislocation

Detecting associated associated injuries

• Clinical examination• X-ray evaluation• CT• Intraoperative evaluation

Detecting associated associated injuries

CLINICAL EVALUATION

• Even minor fractures are painful due to haemarthrosis

• Document forearm rotation after LA injection to joint to rule out mechanical block

DOCUMENT• MCL injury• PIN injury • DRUJ injury

Interroseous membrane injury

DOCUMENT• • • •

BROBERG MORREY MODIFICATION OF MASON CLASSIFICATION 1

• Marginal/ segmental fracture• < 2mm displacement• No block to forearm rotation

BROBERG MORREY MODIFICATION OF MASON

CLASSIFICATION 2

• Displaced segmental fracture• > 2mm/ >30* angulation• Mechanical block to forearm rotation

BROBERG MORREY MODIFICATION OF MASON

CLASSIFICATION 3

• Communited entire radial head fracture

BROBERG MORREY MODIFICATION OF MASON

CLASSIFICATION 4

• Radial head fracture associated with elbow dislocation

HOTCHKISS MODIFICATION OF MASON

CLASSIFICATION• TYPE 1- minimally displaced radial head

fracture , no block to forearm rotation, can be treated non operatively

HOTCHKISS MODIFICATION OF MASON

CLASSIFICATION• TYPE 2- displaced partial radial head

fracture that blocks forearm rotation/ entire radial head fracture amenable to fixation, treatment is ORIF

HOTCHKISS MODIFICATION OF MASON

CLASSIFICATION• TYPE 3- communited entire radial head

fracture not amenable to fixation, radial head excision or replacement .

Goals of treatment• Correcton of block to free forearm

rotation• Stable elbow• Prevent late arthrosis• Early mobilisation

Non operative treatment• Modified mason 1 fractures• No associated lig injuries• No bony block to ROM

Non operative treatment• Early(3-4d) ROM • Large undisplaced fragments need to be

monitored with x-ray• Loss of elbow extension• Redisplacement• Non union

• Various studies have reported 90% favourable results in mason 1 injury

Non operative treatment• 80% favourable result with

MASON 2&3 fractures treated nonoperatively and added with delayed radial head excision when required for pain(JBJS (Am) :86-A; 3, 570.)

Non Operative Rx

More than 2 wks POP

Retain/Regain

Safe Zone• Smith and hotchkiss• 65* ant and 45* pos to line

bisecting anterior and pos head with arm in neutral rotation

Safe Zone

ORIF. implant in SAFE ZONE

CONSIDER ORIF • Displaced MASON 2(>2mm)

partial radial head fractures which block forearm rotations

• Entire radial head fractures with unstable elbow if

– Less than three articular fragments– Sufficient size and bone quality ti accept

screws– No metaphyseal bone loss

Partial radial head fracture

Entire radial head fracture

• Better understanding of anatomy and safezones for implant and current implants have improved clinical results of internal fixation

• King et al have repoted 100% excellent results with internal fixation for Mason 2 fractures

• They have reported only 33%good results with Mason 3 fractures treated by internal fixation

• Due to inadequate fixation or selection of fracture pattern- include

• Nonunion• Restriction of forearm motion• Implant failure • Infection • PIN injury

Inadequate fixation

Extending the indication

Primary Radial head excision

Primary Radial head excision

Modified mason 3 fractures with» Intact MCL » No injury to DRUJ» Coronoid and

olecranon intact• Partial radial head fractures

hindering forearm rotation not amenable to reconstruction

15 yr follow up studies• Antuna et al- 81 % painfree ,

radigraphic OA did not produce clinical symptoms

• Hebertson et al- 90% excellent results, OA changes in 50%

COMPLICATIONS• LOSS OF ELBOW MOTION• LOSS OF STRENGTH• ELBOW OA CHANGES• PROXIMAL MIGRATION OF

RADIUS( up to 2 mm assymptomatic)

• WRIST PAIN• VALGUS INSTABILITY OF ELBOW

EVOLVING

?

Radal head arthroplasty

• Silicone prosthesis• Insabilty• Destructive synovitis • Discarded

• Metal prosthesis– Press fit / cemented– Smooth stem – Unipolar or modular bipolar head

• Smooth stem• Act like spacer• Produce

radiolucencies but asymptomatic

• No overstuffing of radiocapitellar joint

• Fixed stem• Overstuffing if radiocapitellar joint if

prosthesis more than 1 mm proximal to coronoid process

• Open up elbow on lateral side• Capitellar wear and synovitis• So exact sizing must

• No significant diff b/w monopolar or bipolar heads

Over stuffing with opening up

TAKE HOME MESSAGE• Isolated radial head fracture do

occur but is rare• Always look for wrist or elbow

ligamentous injury• Document forearm rotation• Nonoperative treatment involves

supervised mobilization NOT immobilization

TAKE HOME MESSAGE

• Selection of type of fracture amenable to fixation crucial

• Follow safe zones for implants• Radial head arthroplasty is

still evolving

DIDN’T MEAN TO CONFUSE!!!!!!!!!!