Anterior Glenohumeral Instability

ANTERIOR GLENOHUMERAL INSTABILITY

Jason Phillips

Normal Anatomy: Labrum increases

depth of glenoid IGHL 10 static

check to A/P and inf @ 45-900

SGHL and MGHL play stabilizing roles in lower ranges of abductionInferior Glenohumeral

Ligament Complex

Hunt et al. JAAOS 2007

Normal Anatomy: IGHL complex

forms “Hammock” Anterior band

resists anterior translation in Abd/ER

Glenoid “bare spot” is central

History: Arm in Abducted/ER positon Was an ER reduction required? Age? Contact athlete/Military? Position? Ultimate goals? End/Beginning of Season?

Physical Exam: Apprehension-

Relocation (Instability) AbER reproduces

symptoms Posterior force

relieves Load & Shift (Laxity)

Grade I – Up face Grade II – To Rim w/

immediate reduction Grade III – Over Rim

Bahk et al. AJSM 2007

Laxity or Excessive

TranslationDoes Not

Equal Instability

EUA is Critical: Compare translation of BOTH shoulders for any

increase in anterior translation

How should we treat the primary event?

Risks for recurrent instability Position of immobiliztion Length of immobilization Meeting patients goals and expectations

Risks for Recurrent Instability

Rowe 1980 1

<20yo = 94% recurrent instability 21-30yo = 79% 31-40yo = 50% >40yo = 14%

Arciero 1989 2

Ave age 18yo (17-22) 3wks of immobilization (position not specified) 92% recurrence if treated nonoperatively

1. Rowe CR. Acute and recurrent anterior dislocations of the shoulder. Ortho Clin North Am 1980;11:253-70.2. Wheeler JH, et al. Arthroscopic vs. Nonoperative treatment of acute shoulder dislocations in young athletes.

Arthroscopy 1989;5:213-217.


Arciero et al. Arthroscopic bankart vs nonoperative treatment for acute, initial anterior shoulder dislocations. AJSM 1994;22:589-594.


Group 1 = immobilized IR for 3-4 weeksGroup 2 = immobilized IR until patient felt comfortableGroup 3 = immobilization less than 3 weeks

Hovelius L, et al. Nonoperative treatment of primary anterior shoulder dislocation in patients forty years of age and younger. JBJS Am

2008;90:-45-952.



2008;90:-45-952.



2008;90:-45-952.

Keys1. Primary

dislocation2. 4wks

immobilized IR

Robinson CM, et al. Functional outcome and risk of recurrent instability after primary traumatic anterior shoulder dislocation in young patients. JBJS AM 2006;88:2326-2336.

Bushnell BD, et al. Bony instability of the Shoulder. Arthroscopy 2008;24:1061-1073.

Balg F, Boileau P. The instability severity index score: A simple pre-operative score to select patients for arthroscopic or open shoulder stabilisation. J Bone Joint Surg Br 2007;89:1470-1477.




Glenoid Bone Loss: Biomechanical Evidence

Osseous defect at least 21% of glenoid length may cause instabilityItoi E et al. JBJS(A) 2000 Jan

Anteroinferior glenoid defect diminished stability by almost 50%Bone grafting increased stability by 150% to 230%Montgomery WH et al. JBJS (A) 2005 Sept.

Risk Factors for Failure

194 consecutive arthroscopic Bankart repairs; 101 contact athletes

Recurrence in Contact Athletes: Without significant bony defects: 6.5%With significant bony defects: 89%

Engaging Hill-Sachs Glenoid bone loss 25%

Burkhart SS, DeBeer JF. Traumatic glenohumeral bone defects and their relationship to failure of arthroscopic bankart repairs: significance of the inverted-pear glenoid and the humeral engaging hill-sachs lesion. Arthroscopy 2000;16:677-694.


Burkhart SS, DeBeer JF. Traumatic glenohumeral bone defects and their relationship to failure of arthroscopic bankart repairs: significance of the inverted-pear glenoid and the humeral engaging hill-sachs lesion. Arthroscopy 2000;16:677-694.


Quantifying the Risk Factor Cadaveric study : Quantify glenoid bone

loss by arthroscopic means “The bare spot of the glenoid…consistent

reference point from which to determine glenoid bone loss…”

Burkhart SS, De Beer JF et al. Arthroscopy, 2002 May

Itoi E, et al. The effect of glenoid defect on anterior inferior stability of the shoulder after bankart repair: a cadaveric study. JBJS Am 2000;82:35-46.






3B Effect1. Labral repair (Bumper effect)2. Increased bony contact via coracoid transfer (Bony effect)3. Sling effect of conjoined tendon and lowered subscap (Belt or sling

effect)

Boileau et al. Orthop Clin N Am 2010;41:381-392.

Position/Length of Immobilization

Paterson WH, et al. Position and duration of immobilization after primary anterior shoulder dislocation: a systematic review and meta-analysis of the literature. JBJS AM 2010;92:2924-2933.











Itoi, JBJS 2007 RCT, Level II, 2yr f/u 198pts sling vs 100ER x 3wks (ER group more

compliant (68% vs 80%) ER group w/ reduced recurrence (38% Rel.

Risk)

Itoi, JBJS, 2007 Immobilize 100 ER Must initiate tx early Most effective if

<30yo

Conservative Treatment:

Strengthen GH rotators and scapular stabilizers

Injury Prevention Graduated

Return GOAL –To keep

head centered

Scapular Exercises: Push-up plus Bear hug Seated rows Shrugs Upright rows

Moseley et al., AJSM 1992.Decker MJ, Hawkins RJ, AJSM 1999.

Arthroscopic Repair after Primary Event?

Arthroscopic Repair after Primary Event?

Results of Arthroscopic Repair: Contact Athletes

Sample Follow Up Recurrence

O’Neill JBJS 1999

41 52 months 5%

Mazzocca AJSM 2005

18 37 months 11%

RobinsonAOSSM 2006

28 51 months 7%

Risks after Primary Repair

Porcellini G, et al. JBJS AM 2009;91:2537-2542.

Risks after Primary Repair

Results of Latarjet At 15yrs, 98%

excellent or good At 15yrs, only

4/118 redislocated (3%)

Hovelius L, et al. JSES 2004;13:509-516.

Tibial Plafond Allograft

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Anterior Glenohumeral Instability