Date post: | 11-Apr-2017 |
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Health & Medicine |
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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• 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!!!!!!!!!!