1. Lateral Elbow Instability
Travis Marion, MD. MSc. BEd.
Academic Half Day
Apr 2012

2. Outline Intro – definitions Anatomy Biomechanics Evaluation
Mechanism of injury
Acute  Terrible Triad
Fracture classification
Management
Reconstruction Priniciples
Outcomes
Chronic  PRLI

3. Anatomy

4. Anatomy Proximal Ulna Greater sigmoid notch Lesser sigmoid notch
Sublime tubercle
Coronoid process
Greater sigmoid notch articulates with the trochlea
Lesser articulates with the radial head forming the radioulnar joint
Coronoid process serves as an important anterior and varus buttress

5. Anatomy
Troclear notch provides nearly 180º of capture with posterior 30º tilt
Central ridge interdigitates with groove further enhancing stability

6. Anatomy Coronoid Process Tip Body Anterolateral facet
Anteromedial facet
6mm from capsule
12mm from brachialis
18mm from MCL
No soft tissue structures routinely attach

7. Anatomy Radial Head Articulates Safe Zone2 Capitellum Radial notch
Radial head articular dish and margin covered by articular cartilage
Forearm in neutral lateral portion of articular surface devoid of cartilage, does not articulate with capitellum or proximal ulna, important for planning fixation

8. Anatomy MCL21 Anterior bundle Posterior bundle Transverse
Anterior bundle originates anterior inferior aspect of the medial epicondyle, inserts on the sublime

9. Anatomy LCL19,20 RCL LUCL Accessory lateral collateral Annular
LCL – attaches to the lateral epicondyle and fans out to merge indistinguishably with the annular ligament
LUCL – a thickening of the capsule, from isometric point on lat epicondyle, inserting on the supinator crest. Serves as lateral stabilizer (tight in varus) and posterior buttress for the radial head.
RCL inserts on the annular
ALCL – stabilizes the annular ligament during varus stress

10. Biomechanics

11. Biomechanics Primary Stabilizers Secondary Stabilizers
Ulnohumeral articulation3
MCL
LCL complex4
Secondary Stabilizers
Radial capitellar4, 30
Joint capsule
Common flexor/pronator and extensors
Compressive force
Anconeus, triceps and bracialis
Rotatory stabilizer
ECU, EDM
Ulnohumeral resists anterior-posterior compressive forces
Coronoid beyond 30 degrees of flexion more than 50% resistance to posterior subluxation
Biomechanical studies have shown importance for axial, varus, posterior medial and lateral rotatory forces
MCL important for valgus and posteromedial stability, anterior band of primary importance
LCL varus and posterolateral rotatory instability – cadaveric study demonstrated that an isolated removal of the LCL resulted in mean posterolateral rotatory laxity of 33º from 5.4º
Radial capitellar – secondary valgus stabilizer and compressive loads – cadaveric study demonstrated 9.6º posterolateral rotatory laxity in isolated radial head resections (represented a doubling of laxity)
post traumatic excision revealed reduced arc flexion (mean 103º), 5/7 perceived instability, 100% reported weakness, and all had positive pivot shift)

12. Evaluation

13. Evaluation History Physical Physical Closed reduction Imaging Chronic
Severity
Mechanism
Precipitants
Chonic
Inciting event
Clicking/snapping/clunking/locking
Apprehensive maneuver
Past medical history
Physical
Acute
Inspection
Open vs closed
Alignment
Joint above and below
Detailed neurologic
Physical
Chronic
Full pain free ROM
Pain free stressing
Special tests
Closed reduction
Imaging
Radiographs
pre/post reduction
AP/Lat/Oblique CT
History
Events
severity and mechanism – Young high energy with more ligamentous and osseous disruption vs elderly low energy only ligamentous
Mechanism allows surgeon to predict injured structures
Precipitants of fall/instability – progressive reduction in required amount of force, reduction movements
clicking/locking/clunking/locking typically in extension half of arc and in supination
Apprehensive maneuver – push off when getting out of a chair
- Past medical history – generalized ligamentous laxity or varus inclinations of the distal humerus secondary to pediatric SC #’s
Physical
Imaging
- Line through the radial head should intersect the centre of the capitellum regardless of projection

14. Instability Classification

15. Classification18 Timing (acute, chronic or recurrent)
Articulations (elbow vs radial head vs both)
Direction of displacement (valgus, varus, anterior, posterolateral rotatory)
Degree of displacement (subluxation or dislocation) – see slide 18
Simple or complex
2) Elbow – most common category of elbow instability involving the hinge joint
Radioulnar – usually traumatic and associated with monteggia
Elbow and prox radioulnar
3) Posterolateral rotatory most common

16. Mechanism

17. Mechanism of Injury FOOSH, elbow extended Posteriorly directed force3
Ulna levers out of trochlea
Valgus stress/posterolateral roll out/supination6
Capsuloligamentous failure lateral to medial, MCL anterior bundle last to rupture6
Radial head, coronoid fx
Valgus force created as the mechanical axis passes through the lateral side of the joint/body rotates internally on the elbow
Supination movement pushes the coronoid beneath the trochlea/alternatively fracture requiring less external rotatin
Conceivable that can dislocate without MCL rupture

18. Mechanism
0 – reduced
1 - PRLI – posterolateral rotatory instability – first described by O`Driscoll et al, JBJS 1991
2- perched – incomplete, supination allowing the coronoid to traverse inferiorly
3 - dislocation

19. Mechanism Stage 1 lateral disruption (PRLI)
Failure of posterolateral capsular ligaments initial event
LUCL – originally thought to be primary stabilizer
Anatomic study 1997 suggested primary lateral stabilizer combination LCL and annular ligament
ECU and extensor digiti minimi secondary rotatory stabilizers
One histologic study that refutes LUCL as a primary stabilizer and is a mere capsular thickening (1999)
Dunning et al, 2001 demonstrated with annular intact the LCL or LUCL could be transected, in a cadaveric study whereby structures were sequentially sectioned
Concensus that LCL complex combined contributes as the primary stabilizer, most dislocations as force generated across the joint the LCL and casp
Stage 2 anterior and posterior capsular disruption – perched
Stage 3 medial disruption, 3A partial disruption (MCL intact), 3B complete disruption (unstable to valgus, immobilize 30-45º of flexion), 3C (entire distal humerus stripped of soft tissue – stable only at 90º)
Each stage of injury elicits different physical findings

20. Acute Traumatic Instability

21. Classification Simple Dislocations Complex Dislocations
Capsuloligamentous injury
No osseous injury
Complex Dislocations
Associated osseous injury

22. Patterns of Fracture Dislocation
Terrible Triad
Posterior dislocation of radial head
Varus posteromedial rotatory instability
Anterior olecranon fracture dislocations
Will only discuss terrible triad

23. Fracture Classification
Mason Classification
I. non displaced
II. Displaced partial articular
III. Multifragmentary
IV. Described in 1962 by Johnson indicates associated ulnohumeral dislocation
Morrey Modified Classification
Include radial neck fractures
Quantify definition of displacement  fragments >30% with 2mm
Include dislocation

24. Fracture Classification
Regan and Morrey7
O`Driscoll8
Fracture Classification
Regan and Morrey
Tip - avulsion
≤ 50%
> 50%

25. Fracture Classification
O`Driscoll
Tip – do not pass the sublime tubercle
Subtype I – less than 2mm
Subtype II – more than 2mm and largely associated with triad injuries
Anteromedial
Subtype I – medial to tip to anterior of the sublime tubercle
Subtype II – extend to sublime tubercle with extension to the tip
Subtype III – anteromedial rim and entire sublime tubercle with/without tip
Base
Anteromedial fractures do not occur with the same posterolateral rotatory instability rather the opposite. Axial force in combination with posteromedial rotation, varus force, and elbow flexion causing the medial trochlea to abut the anteromedial facet of the coronoid. Involves disruption of the LCL if no associated olcranon fracture

26. Traumatic Instability
Terrible Triad1
Elbow dislocation
Coronoid fracture
Radial head fracture

27. Management
Follows the nature of the injury – lateral to medial

28. Management Nonsurgical
Concentrically reduced ulnohumeral and radiocapitellar
Stable to allow sufficient ROM (extension to 30°)
Congruency evaluated under fluoroscopically
CT evaluation
Radial head fx minimally reduced with no mechanical block
Type I coronoid fracture
Tx as simple dislocation
Splint at 90°
Isometric biceps/triceps

29. Management Surgical Incision Advantages Posterior
Access to medial and lateral
Precludes requirement for secondary incision
Reduced injury to cutaneous inervation9
Improved cosmesis
Disadvanages
Large flaps

30. Management Kocher EDC split Anconeus (radial) ECU (PIN)
Kocher/EDC both allow access to the radial head and LCL

31. Management No Replacement Pros Cons No healing required
Exposure to coronoid
Faster recovery
Cons
Non anatomic
Overstuffing
Stiffness
Management of radial head fractures as per Hotchkiss: Think Mason Classification
Do nothing
Fix
Replace

32. Management Yes ORIF Pros Cons Anatomic No overstuffing Non union
Malunion
Implant complications
PIN palsy
Fix – no neck fracture, Minifrag, headless screws to avoid clicking

33. Management Yes No One less incision Medial approach
No ulnar nerve dissection
Amenable to ORIF vs suture technique
Use targeting devices to aid in fixation positioning
Medial approach
Hotchkiss
Can address trochlear fractures
Ulnar nerve dissection
May address MCL if warranted
Can perform a taylor if require humeral reduction/fixation
The brachial fascia is incised along the anterior aspect of the septum, and the flexor-pronator group is released from the supracondylar ridge. The flexor group is split longitudinally at the distal aspect, taking care to leave the posterior aspect of the FCU origin intact on the medial aspect of the distal humerus. The brachialis, flexor carpi radialis, and pronator teres muscles are elevated off the anterior capsule. Sufficient elevation of these muscles makes it possible to see across to the lateral aspect of the anterior elbow joint. A cuff of tissue may be left on the ridge so that the muscle group can be repaired at the end of the procedure.

34. Management LCL Repair Origin at isometric point on lateral epicondyle
Suture anchors vs bone tunnels
Check anatomy
Check stability
If unstable repair the MCL
Persistent instability = external fixator
Typically torn at origin, bare lateral epicondyle
Check the reconstructed anatomy under fluoroscopy
If persistent instability and appropriate reconn, Repair MCL

35. Reconstruction Principles
< 10% coronoid fractures little effect on stability5
MCL repair more effective than coronoid repair5
Most triads involve more than 10%
MCL most important valgus stabilizer
Requires radial head
Radial head acts as buttress
Radial head tensions LCL providing varus stability
In biomechanical cadaveric studies, MCL more important than coronoid if less than 10% in setting of triad

36. Outcomes Pugh and McKee, 2002 Pugh et al, JBJS AM, 2004
Mean arc 20º and 135º
Mean rotation 135º
Delay in treatment or revision 20% greater loss of motion
25% revision
Pugh et al, JBJS AM, 2004
36 patients, multicentred
112º flexion arc
136º rotation
15 excellent, 13 good, 7 fair, 1 poor
8 revisions (synostosis, instability, contracture release, wound infection)
Prolonged immobilization worse prognosis
No defined length of immobilization resulting in poorer outcomes. Previous studies more than 4 weeks led to instability.
Better to manage a stiff congruent elbow vs mobile incongruent

37. Outcomes Frothman et al, J Hand Surgery, 2007 Similar Findings
30 patients
117º flexion arc
Rotation 135º
77% excellent results
Single surgeon, no MCL repairs
Similar Findings
Chemama et al, Orthop Traumatol Surg Res, 2010
Rodriguez-Martin et al, Int Orthop, 2011
Jeong et al, J Orthop Sci, 2010
Lindenhovius et al, J Hand Surgery 2008
Acute within 2 weeks (ave 6 days) vs subacute repair > 3 weeks (ave 7 weeks)
No difference except 20º more flexion arc

38. Chronic Instability

39. Posterolateral Rotatory Instability
Most common type of symptomatic instability
First described 1991
Recurrent proximal radio-ulnar displacement
Prox radius and ulna rotate externally in relation to the humerus
Radioulnar joint intact and rotates as a single unit as opposed to isolated radial head dislocation
Lateral elbow instability with an absence of physical findings

40. PRLI Failure of LCL complex Physical exam Trauma iatrogenic
chronic attenuation29
Physical exam
PRLI - analogous to pivot shift
Table top relocation test
Trauma - typically avulsed from origin, failure of LCL to heal in anatomic position on lateral epicondyle in case of trauma
Iatrogenic – surgical approaches, arthroscopic releases
Chronic attenuation – longstanding cubitus varus (pedriatric SC fracture) which may create an external rotatory moment on the ulna, chronic overuse – chronic crutch walking (polio)

41. PRLI Radiographs Avulsion of LCL complex Degenerative changes
Faber/King lesion (post capitellum lesion analogous to hill sachs)
Drop sign --. Ulnohumeral distance > 4mm on plane lateral

42. Management Management Avoid further ligamentous injury
Arthrotomy anterior to LUCL, anterior capsular release
Suture anchor vs lateral ligamentous reconstruction
Ligamentous graft – palmaris, plantaris
Drill placed in supinator tubercle, second drill hole proximal to annular ligament creating bony tunnel (both extra-articular)
Subsequent tunnels drilled in lateral epicondyle

43. Outcomes Jones et al, J Shoulder Elbow Surg, 2012
8 patients with purely ligamentous PRLI
Surgical graft reconstructionr
Mean f/u 7.1 years
75% resolution
25% occasional instability with ADLs
Olsen and Sojberg, JBJS Brm 2003
Triceps tendon graft in 18 patients
4 persistent apprehension
5 moderate pain
Sanchez-Sotelo et al, JBJS Br, 2005
12 patients, ligamentous repair, 32 reconstruction
5 persistent instability (3 from repaired, 2 from recon)
17 rated excellent
17 good
10 fair
Similar Findings
Lee and Teo, J Shoulder and Elbow, 2003
Primarily case reports on various techniques
Decreased persistent instability with reconstruction
Persistent pain associated with osteochondral lesion
O’Driscoll et al, Instr Course Lect, 2001  90% satisfaction if no associated degenerative arthritis

44. References 1Hotchkiss, Rockwood and Green’s, 1996
2Matthew et al, JAAOS, 2009
3Mezera and Hotchkiss, Rockwood and Green’s, 2001
4Schneeberger et al, JBJS AM, 2004
5Beingessner et al, J Shoulder Elbow Surg, 2007
6O’Driscoll et al, JBJS, 1991
7Regan and Morrey, JBJS AM, 1989
8O`Driscoll et al, Instr Course Lect, 2003
9Dowdy et al, JBJS BR, 1995
10Morrey et al, CORR, 1991
11Pugh and McKee, 2002
12Pugh et al, JBJS AM, 2004
13Frothman et al, J Hand Surgery, 2007
14Chemama et al, Orthop Traumatol Surg Res, 2010
15Rodriguez-Martin et al, Int Orthop, 2011
16Jeong et al, J Orthop Sci, 2010
17Lindenhovius et al, J Hand Surgery 2008
18O’Driscoll, CORR, 2000
19Mehta and Bain, JAAOS, 2004
20Imatani et al, Jshoulder Elbow Surg, 1999

45. References 21Morrey and An, Clin Orthop, 1985
22Cohen and Hastings, JBJS Am, 1997
23Dunning et al, JBJS AM, 2001
24O`Driscoll et al, JBJS, 1991
25Jones et al, J Shoulder Elbow Surg, 2012
26Sanchez-Sotelo et al, JBJS Br, 2005
27Lee and Teo, J Shoulder and Elbow, 2003
28Olsen and Sojberg, JBJS Br, 2003
29Beuerlein et al, JBJS Am, 2004
30Hall and McKee, JBJS, 2005

46. Questions

47. Nathan L Sacevich circa 1998
Future ambition: sports medicine doctor
Most memorable experience: losing the soccer championship
Nickname: Nate Dogg
Closet friends: Mack Daddy, Mr Sauce, P Squared (no mention of Travis)
Remembered by: his “stylo” (his style?)
When no one was looking: he liked to get his thug on
People thought:
he looked like a back street boy
“the illest playa”