June 11, 2013

Joseph C McCormick III, MD

Orthopaedic Surgeon

Affinity Medical Group

Disclosure Slide

• Nothing to disclose in terms of financial or industry relationship.

Goals

• Review anatomy of acromioclavicular joint

• Mechanism of injury

• Classification of acromioclavicular injuries

• Define treatment based on grade

• Review of clinical outcomes and biomechanical literature regarding AC Injury

History

• Hippocrates first to distinguish AC injuries from GH joint injuries and to delineate the mechanism of injury

– “Physicians are particularly liable to be deceived in this accident, so that they may prepare as if for dislocation of the shoulder;…”

History• Galen diagnosed his own AC dislocation sustained while wrestling

• Treated himself as Hippocrates suggested with tight bandages to hold clavicle down with arm elevated

• Abandoned this treatment after a few days because it was so uncomfortable

• Hippocrates felt that no “impediment, great or small will result from such an injury”

• Furthermore he stated the deformity cannot be restored to its “natural situation”

• This statement has been received by the ortho community over the years as a challenge.

• First reported surgical procedure for AC dislocation by Cooper in 1861

AnatomyDiarthrodial joint

Has fibrocartilaginous disk

Clavicle rotates with external rot and abduction

AC ligaments stabilize in AP direction, insert on clavicle 1.5 cm from joint – superior and posterior fibers most robust

CC ligaments – predominant restraint to vertical translation

Anatomy

Coraco-clavicular Interval: average 1.1 - 1.3 cm

Trapezoid: attaches anterior and lateral on clavicle Average distance distal clavicle to center 2.54 cm males/ 2.29 cm

females

Conoid: attaches posterior and medial on clavicle Larger of the 2 CC ligmaments Next ligament to fail after AC ligament disruption Ave distance distal clavicle to medial aspect of conoid tuberosity 4.72 cm

males/ 4.28 cm females OKU 4 Sports Medicine

Dynamic stabilizers

Muscles that cross joint important to stability

Anterior deltoid helps to suspend arm from clavicle attachment

Trapezius has confluent fascial attachment over dorsum of acromion

Importance noted in the higher grades of injury, i.e.. Type V

Mechanism

Direct vs. IndirectDirect by far most common

Direct force to acromion with the shoulder adducted, usually result of fall

Acromion moves inferiorly and medially while clavicle is stabilized by the SC joint ligaments

Force results in systematic failure of stabilizing structures as it propagates

AC ligaments/capsule CC ligaments deltotrapezial fascia

Indirect is more rare results from fall onto outstretched

hand/arm with superiorly directed force typically affect AC ligaments only

DiagnosisDuring exam should be sitting or standing w/o support for the injured arm

Check for tenderness to palpation at the AC joint and the CC interspace

If patient can tolerate check joint for stability

Check to see if reducible

Examine SC joint as well

Neurologic exam to r/o brachial plexus injury

Radiographs

AP, axillary lateral and Zanca views can be taken to best assess the joint

Should be taken with the patient upright and no support of injured arm

Stress views ??

Stress Radiographs ?

ASES Survey

81% Not in ER91% No change in

Treatment

Stress views are costly, painful, and don’t often provide new info, so aren’t routinely used anymore

Radiographs

Zanca View Underpenetrated

view 10-15 degree

cephalic tilt

Axillary View Assess horizontal

displacement

Biplanar Instability/Displacement

Vertical Horizontal

Dynamic Axillary View Tauber et al AJSM 2010

Gleno-acromio-clavicular angle

May help detect previously missed horizontally unstable injuries.

Classification

Originally described by Tossy and Allman in the 1960’s

Included types I,II, and III

In 1984, classification modified by Rockwood

Now types IV, V, and VI added, better predictor of prognosis, need for surgical intervention

Type I

No visible deformity

Swelling/pain over AC joint

No pain over CC interspace

Radiographs appear normal

Type II

AC ligaments disrupted

Horizontally unstable

Absent or very minimal vertical instability

Tenderness over CC interspace

Abnormal radiographs

Type III

Horizontal and vertical instability

Radiographically AC joint is dislocated

Pain in CC interspace

Typically pain is greater with Type III and higher injury

Historically more debate with choice of treatment

Type IV

AC joint dislocation

Clavicle displaced posteriorly

AC joint irreducible on exam

Occasionally associated with SC dislocation

Type IV

Type V

All stabilizing ligaments disrupted

Deltoid and trapezius muscles and fascia at least partially detached from clavicle

AC joint irreducible

May develop symptoms due to brachial plexus traction

Type V

Type VI

High energy variant

Result of hyperabduction and external rotation

Distal clavicle comes to rest in subcoracoid position

Summary

Treatment I and IINonsurgical management is uniformly recommended for type I and II injuries

A period of immobilization in a sling for comfort until pain subsides

Usually 7-10 days for type I, up to 2 weeks for type II

Possible anesthetic injection for return to high level play

Unloading foam padding

Once acute pain has subsided rehabilitation program is instituted

Not So Benign?Mouhsine et al JSES 2003

33 patients Grade I and II injuries treated conservatively

27% required surgery within 36 months (6 distal clavicle excision, 3 Weaver-Dunn)

24 pts remaining assessed 6 yrs post injury both clinically and radiographically

Only 16% patients with no radiographic degenerative changes or osteolysis evident

Not So Benign?

Mikek AJSM 2008

23 patients with Type I and II AC Disruption with 10 year Follow-up

52% reported occasional symptoms Constant score 70.5 injured vs 86.8 (P < .001) UCLA score 24.1 vs 29.2 (P < .001) Simple Shoulder Test 9.7 vs 10.9 (P < .002)

RehabilitationEarly focus is on passive and active ROM

Once symmetric and painless ROM achieved then progress to isometric shoulder strengthening

Isotonic strengthening is next with gradual escalation of strength and endurance with return to sport in mind

Return to sport is not allowed until painless/full ROM is achieved and strength has returned.

This may take longer for type II injuries, and some recommend contact sports/heavy lifting should be avoided for 2-3 months

What about Type III injuries?

Type III injuries

In 1974 Powers and Bach reported that 92% of 116 type III injuries were treated operatively

Of 163 ortho residency program chairmen surveyed at that time 91.5% advocated surgical treatment

In 1992 Cox surveyed 231 chairmen and 62 orthopedists participating in care of athletes

72% of chairmen favored non-op management 86% of team orthopedists favored no-op management

trend toward non-surgical management is well supported in the literature

Natural History of Type III

Schlegel et al AJSM 2001 Prospective study non-operative treatment of

20 patients with Type III AC injuries assessed strength, ROM, subjective questionnaire

Ave Sling use: 8 days (2-25) Ave return to work: 9 days (1-24)

7 professionals, 8 laborers, 2 students, 3 unemployed/retired

Analgesic discontinued: 1 wk (15); 2 wk (5)

Natural History of Type IIISchlegel et al 1 year resultsAll had full, pain free, symmetric ROM

No statistical difference in dynamometer strength

A statistically significant 17% decrease in bench press strength on injured side was noted

80% favorable subjective results

20% unfavorable 3 of 4 secondary gain bias Only 1 of 4 elected to

undergo surgical intervention

Non-op managementGalpin et al 1984, retrospective review comparing outcome in type III injuries, 21 treated non-op, 16 with surgery (Bosworth screw and ligament repair) avg 3 yr f/u

Showed overall chances of late pain or altered function were not statistically different

Surgical patients took longer to become pain free, and longer to return to work2.8 vs. 4.5 months, and 2.6 vs. 6.8 weeks, respectively

Numbers were limited to correlate treatment with patient demands

Glick et al 1977, retrospective review of 35 AC dislocations treated non-operatively. 29/35 had no pain, none had disabling pain, 31/35 had no weakness, none had disabling

weakness

None of the patients who had supervised rehabilitation complained

8/10 throwers were not affected while throwing, two were professional quarterbacks and one a collegiate javelin thrower

Concluded that complete reduction not necessary for satisfactory function

Randomized prospective trialBannister et al 1989 – 60 patients with acute AC dislocations random number drawn to allocate operative vs. no-op treatment

Faster return to work for manual and clerical workers treated non-operatively

After 4 years of f/u no real difference between the two groups in terms of pain/function with one exception

In the 12 dislocations with more severe dislocation, i.e.. Type V, surgery gave better results

Concluded that younger patients with severe displacement are more likely to achieve an excellent result if stabilized early

Felt that surgical treatment created greater morbidity in the lesser grades of injury

Slight strength loss?Wojtys et al, 1989, retrospective review of 22 patients with type III treated non-operatively

Showed that laborers and athletes can recover strength and endurance, return to pre-injury level of activity without surgery

Strength testing showed some statistically insignificant strength loss, indicating that the strength and endurance advantage one might expect of the dominant arm may be lessened or lost

May be a factor to consider for those requiring high levels of shoulder strength for work/athletics, or those involved in highly repetitious endurance activities such as swimming/pitching

Rarity of type III AC separation precludes study of significant numbers with controls to determine treatment that is best for athletes who rely on their elite throwing ability

McFarland MLB Survey Study 1997

American Journal of Orthopedics, Nov 1997

Phillips et. al CORR 1998 Meta-analysis Type III AC Injury

OP vs NON-OP

Pain absent or minimal 93% 95%

ROM normal/near normal 86% 95%

Strength normal /near normal 87% 91%

Subsequent surgery 59% 6%

Operative results and Timing

Weinstein et al AJSM 1995 44 patients Type III Injury

27 acute, 17 late repairs

CC nonabsorbable suture repair/recon

15/27 and 17/17 CA transfer

89% satisfactory results, 93% return to sports Timing Acute (<3 wk) vs Late (> 3wk)

Satisfactory results 96% vs 77%

Loss of reduction 15% vs 29%

Types IV, V, IV

All require operative intervention

All stabilizers, static and dynamic are injured

Treatment Old School

Not well tolerated, Dermal Complications

Surgical management

Fixation across AC joint

Fixation between coracoid and clavicle

Ligament reconstruction

Distal clavicle excision

Acromioclavicular Fixation

Pin fixation

Has been abandoned since reports of rare pin migration Heart, Lung,

Great vessels

Acromioclavicular fixation

Hook Plate

Only used for acute injury

Requires subsequent surgery for removal

Fixation between coracoid and clavicle

Bosworth popularized the use of a screw for fixation of the clavicle to the coracoid

This technique initially did not include recommendation for repair or reconstruction of the CC ligaments

Today the use of screws and suture loops has been described alone and in combo with ligament reconstruction

Placement of synthetic loops between the coracoid and clavicle can be done arthroscopically, main advantage: doesn’t require staged screw removal

Ligament reconstructionWeaver and Dunn were the 1st to describe transfer for the native CA ligament to reestablish AC joint stability

Their technique described excision of the distal clavicle with this ligament transfer

Construct can be augmented with a suture loop for protection until the transferred ligament heals

Ligament Reconstruction

Open and Arthroscopic techniques

Restore Anatomy

orthoillustrated.com

Anatomic Ligament Reconstruction

Alternative technique is use of semitendinosus autograft for reconstruction

Loop around or fix into coracoid, then fix through two separate clavicle bone tunnels to approximate normal anatomic location of CC ligaments

Recent biomechanical studies have demonstrated the superiority of this construct

Biomechanical studies Lee et al., 2003 – 11 cadaveric shoulders tensile tested to failure comparing suture loop, CA transfer, and free tendon recon

Reconstructions found to have failure strengths as strong as those of native CC ligaments

CA transfer was the weakest construct, and shows that greatest elongation at failure

Concluded tendon graft reconstruction to be an alternative to CA lig transfer possibly providing a permanent biologic reconstruction

Given its biomechanical properties similar to native CC ligaments, reconstruction with tendon graft may allow for shorter post op immobilization and accelerated rehab program

Biomechanical studies

Mazzocca et al, 2006, studied 42 cadaveric specimens comparing stability of 3 AC joint reconstruction techniques

Anatomic CC reconstruction with tendon graft provided ant, post, and superior stability similar to intact state

Modified Weaver-Dunn had significantly greater laxity compared to anatomic CC recon and arthroscopic reconstruction

Concluded that anatomic reconstruction with free tendon graft may provide stronger, more permanent biologic solution for AC joint dislocation

Newer proposed techniquesGrutter and Petersen 2005 AJSM (Cadaveric study)

Anatomic Reconstruction using FCR graft to reconstruct CC and superior AC ligament

Similar strength as native AC joint in coronal plane

Newer Proposed TechniquesFreedman et al AJSM 2010 (Cadaveric study)

Intramedullary AC reconstruction with 5 cm semitendinosus graft and fibertape

AP translation Intact: 2.34 - 7.86 mm Recon: 1.20 - 2.95 mm

Superior/Inferior translation Intact: 2.56 - 6.16 mm Recon: 2.42 - 4.57 mm

Did not reproduce similar stiffness, load to failure, and energy absorption as intact AC complex

Newer proposed techniques

Improved horizontal stability with addition of intramedullary AC ligament reconstruction. -50% less AP translation

No difference in: - Superior/inferior translation - Load to failure

AJSM 2010

ComplicationsNon operative Pain Post traumatic arthritis/osteolysis Possible neurologic injury Possible strength deficit

Surgical Same as above plus… Clavicle or coracoid fracture Loss of reduction Pneumothorax Neurovascular injury

SummaryType I, II

restricted activity initially Analgesic, Injection Rehabilitation

Type III Controversial- trends toward initial non-operative

management Late reconstruction if symptomatic Optimal strategy has changed and alternated over

time

Type IV,V, VI Repair/reconstruction

Case

HPI: 21 yo R HD male college student presents to clinic after fell off bike over the handle bars onto his R shoulder

Exam: Ecchymosis, Gross deformity R AC joint TTP distal clavicle and CC interspace Distally NVI R upper extremity

Radiographs

Post op

Acute CC repair with Fiberwire Suture Loops

References• Bannister, G, Wallace, W, Stableforth, P.G.: The Management f Acute Acromioclavicular Dislocation. JBJS(Br) 1989; 71-B:848 -50

• Galpin, R, Hawkins, R, Grainger, R: A Comparative Analysis of Operative Versus Nonoperative Treatment of Grade III Acromioclavicular Separations. CORR 1985;193:150-155

• Glick, J, Milburn, L, Haggerty, J, et al: Dislocated acromioclavicular joint. Follow-up study of 35 unreduced acromioclavicular dislocations. Am J Sports Med 1977;5: 264-270

• Lemos, M: The Evaluation and Treatment of the Injured Acromioclavicular Joint in Athletes. Am J Sports Med 1998;26:137-144

• Lee, S, Nicholas, S, Akizui, K, et al: Reconstruction of the Coracoclavicular Ligaments with Tendon Grafts. Am J Sports Med 2003;31:648-654

• Mazzocca, A, Santangelo, S, Johnson, S, et al: A Biomechanical Evaluation of an Anatomical Coracoclavicular Ligament Reconstruction. Am J Sports Med 2006;34:236-246

• McFarland, EG, Blivin, SJ, Doehring, CB, et al: Treatment of Grade III Acromioclavicular Separations in Professional Throwing Athletes. Am J Orthop 1997;11:771-774

• Simovitch, R, Sander, B, Lavery, K, et al: Acromioclavicular Joint Injuries: Diagnosis and Management. JAAOS 2009;17:207-219

• Wojtys, E, Nelson, G: Conservative Treatment of Grade III Acromioclavicular Dislocations. CORR 1991;268:112-119

• Galatz, L, Williams, G: Acromioclavicular Joint Injuries. Rockwood and Green’s Fractures in Adults, 5 th ed. 2002;1210-1244

• Mazzocca, A. Arciero , R . Evaluation and Treatment of Acromioclavicular Joint Injuries. Am J Sports Med 2007 35: 316

• Grutter, P. Petersen, S. Anatomical Acromioclavicular Ligament Reconstruction. Am J Sports Med 2005 33: 1723

• Mikek, M. Long-Term Shoulder Function After Type I and II Acromioclavicular Joint Disruption. Am J Sports Med 2008 36: 2147

• Schlegel, T et al. A Prospective Evaluation of Untreated Acute Grade III Acromioclavicular Separations. Am J Sports Med 2001 29: 699

• Gonzalez-Lomas, G et al. Intramedullary Acromioclavicular Ligament Reconstruction Strengthens Isolated Coracoclavicular Ligament Reconstruction in Acromioclavicular Dislocations. Am J Sports Med 2010 38: 2113

• Tauber, M, et al. Dynamic Radiologic Evaluation of Horizontal Instability in Acute Acromioclavicular Joint Dislocations. Am J Sports Med 2010 38: 1188

• Mouhsine E, Garofalo R, Crevoisier X, Farron A. Grade I and II acromioclavicular dislocations: results of conservative treatment. J Shoulder Elbow Surg. 2003;12:599-602

• Phillips A, Smart C, Groom A. Acromioclavicular dislocation. Clin Orthop Relat Res. 1998;353:10-17

• Weinstein, D et al Surgical Treatment of complete acromioclavicular dislocations. AJSM 1995 23: 324-330

• Kibler, B. AAOS OKU Sports Medicine 4 2009• Google Images

Thank You

• Questions?