Anterior Shoulder Instability in Sport Current Management Recommendations (1)

Anterior Shoulder Instability in SportCurrent Management Recommendations

Maj. Winston J. Warme,1 Col. Robert A. Arciero1 and Ltc. Dean C. Taylor2

1 US Army Joint & Soft Tissue Trauma Fellowship, Keller Army Community Hospital, West Point,New York, USA

2 Orthopaedic Surgery Service at Keller Army Community Hospital, West Point, New York, USA,and the Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA

Abstract In the young athlete, anterior shoulder dislocations are common injuries thatusually result in recurrent instability, and often require surgical treatment. Non-operative treatment remains the initial recommended course for most conditions.Operative treatment has advanced to more anatomical repairs, both open andarthroscopic. The purpose of this paper is to review the evaluation and treatmentof anterior shoulder instability, to include acute dislocations, acute subluxationsand recurrent instability.

INJURY CLINIC Sports Med 1999 Sep; 28 (3): 209-2200112-1642/99/0009-0209/$06.00/0

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1. Acute Anterior Dislocations

An anterior shoulder dislocation usually occursbecause of loads applied to the externally rotatedand abducted shoulder. In boxing, an anterior dis-location can also occur on follow-through if theboxer misses his opponent. These injuries occurcommonly in contact sports, such as football andrugby, or from falls in non-contact sports such asskiing and gymnastics.

1.1 Presentation and Examination

Patients will present in distress, with their in-jured shoulder in internal rotation and adductionwhile supported by the contralateral hand. Therewill be a limited range of motion, loss of the deltoidcontour and a prominent anterior acromion. Axil-lary neuropraxia is associated with 5 to 35% offirst-time dislocations, so a careful neurovascularexamination is warranted and documentation man-datory. Vascular lesions and injuries to other nerves,although extremely rare with low velocity athleticinjuries, should be ruled out.

Radiographs should be obtained to document

complete glenohumeral dislocation and rule outbony injuries. The standard trauma series shouldinclude true glenohumeral anteroposterior, scapularlateral and axillary views. The West Point modifi-cation of the axillary view[1] is helpful in detectingglenoid rim fractures (fig. 1). The scapular lateralview displays the relationship between the glenoidand humeral head. A Stryker notch view helps de-lineate posterolateral humeral head defects (Hill-Sachs lesions). Acceptance of incomplete radio-graphic examinations may lead to undiagnosedchronic anterior dislocations. In one series, missedanterior dislocations resulted in severe articular de-generation requiring total shoulder arthroplasty in9 of 17 cases.[2]

1.2 Treatment and Reduction Techniques

Reduction of the dislocated shoulder is easiestimmediately following the injury. Therefore, in theathletic setting, given a classic history and presen-tation including the absence of crepitus on examin-ation, reductions on the field or in the locker roomare very effective.

In the early period following a dislocation, aself-reduction method will often gently reduce theshoulder. In one self-reduction technique, the pa-tient interlaces his or her fingers around the ipsilat-eral flexed knee and leans backwards. The Milchmanoeuvre[3] is another gentle technique that canreduce the anteriorly dislocated shoulder. In the sit-ting or supine position, the patient gradually ab-ducts and externally rotates the injured shoulderwith assistance from the contralateral hand. Thephysician can apply gentle longitudinal traction atthe elbow and guide the humeral head over the rimwith some rotational assistance as needed. Theshoulder usually reduces before or while the pa-tient’s hand is positioned behind his/her head. Fre-quently, there is no sudden reduction, but the pa-tient notes obvious relief when the arm is returnedto the side.

These gentle self-reduction techniques are mosteffective in the early period following a shoulderdislocation. Other reduction techniques includetraction-counter traction methods. In one commonlyused technique, a sheet is placed through the af-fected axilla and held by an assistant who standsnear the supine patient’s head. Gradual longitudinaltraction is then applied to the injured upper extremity.A satisfying clunk is usually obtained followed bymarked symptomatic improvement in the patient.

If a reduction attempt on the field is unsuccessful,radiographs to rule out associated fractures shouldbe obtained prior to further manipulation of theshoulder. In the clinic or emergency room setting,there has frequently been a significant delay be-tween the dislocation and initial evaluation. If theshoulder has been dislocated for more than 20 to30 minutes, narcotic analgesia and muscle-relaxingbenzodiazepine medications can be helpful. A re-cent report[4] also demonstrated the good tolerabil-ity and efficacy of subacromial and intra-articular1% lidocaine without epinephrine. These investi-gators used a 20cc aliquot and contrasted it withintravenous pethidine/diazepam in a prospectiverandomised fashion. Efficacy of reduction wascomparable and uncomplicated in the lidocainegroup, while 10% of patients in the intravenousgroup experienced respiratory depression and 1 pa-tient required an antidote.

The Stimson method is another reduction tech-nique that can be helpful, especially in a busy emer-gency room setting. With the patient prone, suspend10 to 15lb from the affected extremity for gravity-assisted traction. The patient should note relief withreduction as the gravity traction overcomes themuscle forces. Forceful reductions with attempts tolever the humeral head back into the glenoid fossashould be avoided as they have been associated withiatrogenic fracture.

Once reduced, the neurovascular examination isrepeated. Radiographs (the shoulder trauma series)should be obtained to document an adequate reduc-tion and rule out associated fractures. The upperextremity is placed in a shoulder immobiliser forcomfort. For first-time dislocations, the patientshould be counselled about the natural history, theirrisk for recurrent instability, and non-operative andoperative treatment alternatives.

1.3 Natural History

The natural history of standard non-surgicaltreatment is well documented. The risk of recurrentinstability after an anterior shoulder dislocation isdirectly proportional to activity level and inverselyproportional to age. Therefore, the recurrence rate

Fig. 1. West Point view demonstrating anterior glenoid rim frac-ture (‘bony Bankart lesion’).

210 Warme et al.

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is usually very high for athletes who are, in general,young and active. In patients under 20 years of age,recurrence rates of 68 to 95% have been re-ported.[5,6] One study found a recurrence rate of100% in 21 skeletally immature patients.[7] In theunder 30 years of age group,[8,9] recurrence rates of50 to 64% have been reported, and neither the pre-sence of a Hill-Sachs lesion nor the period of im-mobilisation has influenced the rate of recurrence.Concomitant greater tuberosity fracture, which ispresent in about 3% of cases, is associated with adecreased risk of recurrent instability. Rotator cufftears associated with anterior shoulder dislocationsare present in approximately 15% of 40-year-oldpatients and up to 40% of patients older than 60years of age.

A recent, Swedish, 10-year prospective studyreported a 43% rate of recurrent dislocation for allpatients.[10] In those less than 22 years of age, 70%had 2 or more recurrent dislocations. Risk of recur-rence was greatest in the first 2 years after disloca-tion. Radiographs were taken of 208 shoulders at10-year follow-up and showed mild post-traumaticarthropathy in 11% and moderate to severe degen-erative changes in 9% of patients.

1.4 Treatment After Reducing theDislocated Shoulder

1.4.1 Non-Operative ManagementNon-operative management has been the standard

treatment for patients who present with new onsetanterior instability. The goal of this approach is torehabilitate the dynamic restraint system (deltoid,rotator cuff and scapular stabilisers) back to a nor-mal, functional state while protecting the static re-straints from further injury.

In the adolescent or young adult, 4 to 6 weeksof immobilisation may allow for some soft tissuehealing, but most studies have indicated that im-mobilisation has little or no effect on recurrent in-stability.[7-9,11] Shorter periods of immobilisationshould be used in older patients to prevent residualloss of motion. While the patient is in the immobi-lisation phase, gentle pendulum and Codman’s ex-ercises are started.

The next phase of therapy addresses the dynamicstabilisers of the shoulder. Isometric exercises startedat 3 to 4 weeks strengthen the rotator cuff, deltoidand scapular stabilising muscles. Biceps strength-ening is included, as the long head of the bicepshas been shown to provide an anterior stabilisingfunction.[12] Low-speed isokinetic training followsat approximately 6 to 8 weeks.

Plyometric strengthening and progression tosports-specific exercises in the final phase of reha-bilitation prepare the athlete to return to competi-tion. Muscles lose their dynamic stabilising actionwhen fatigued, and allow increased humeral headmotion, exposing the static restraints to greater stress.For this reason, endurance exercises are prescribedthat prepare the athlete to resume his or her sportsafely.

1.4.2 Operative TreatmentOperative treatment for the first-time dislocator

is a relatively new concept. The rationale is tochange the natural history in the active adolescentor young adult, whose rate of recurrence is high (65to 95%). Arthroscopic studies of acute first-timedislocations have revealed Perthes-Bankart lesionsand haemarthrosis in over 95% of cases.[13,14] Theanterior portion of the inferior glenohumeral liga-ment (IGHL) is detached from the glenoid, exposingthe scapular neck (fig. 2). Restoration of this anat-omy should be the goal of the shoulder surgeon.The anatomy within the first 10 days of a first-timedislocation is well defined, with healthy tissues thatcan be restored to their anatomic positions. In thisenvironment, one could argue that the best time torestore the anatomy is immediately after the firstdislocation.

Investigators at the United States Military Acad-emy (USMA) have prospectively evaluated arthro-scopic transglenoid suture repair and, more recently,bioabsorbable tack fixation for first-time anteriordislocations. In USMA cadets, transglenoid repairshad a recurrence rate of 14versus80% in the non-operative group.[4] Others have had 100% successrates at 2-year follow-up with this technique in ath-letes under 20 years of age.[15]

Anterior Shoulder Instability 211


Since December 1991, 51 additional USMA ca-det athletes with primary anterior dislocation of the

shoulder have selected arthroscopic bioabsorbabletack repair (fig. 3). Thirty-four patients with an aver-age follow-up of 40 months (minimum 2 years)have recently been evaluated. The average age ofthe athletes was 20 years (range: 17 to 23 years).All were immobilised for 4 weeks, followed by arehabilitation programme, and allowed full activityat 4 months after surgery. Twenty-nine shoulders(85%) have remained completely stable and the pa-tients have returned to their pre-injury functionalstatus, while 5 patients developed recurrent insta-bility. Recurrence was associated with bilateralshoulder instability, evidence of sulcus sign (2+)on preoperative evaluation, and atrophic appearanceof the capsulolabral complex at arthroscopy. Arthro-scopic treatment of primary anterior dislocations inthis young, high demand group has reversed thenatural history.

More recently, open surgical repair of first-timedislocations of ‘high risk patients’ has been re-ported.[16] Preliminary results indicate that recur-rence is less than 5%.

Management of the initial, traumatic anteriorshoulder dislocation should be individualised basedon the patient’s age, activity level, subsequent de-mands and pre-injury shoulder status. The majorityof patients can be managed effectively with a non-surgical approach. However, the high demand pa-tient, aged 17 to 24 years, has a very high rate ofrecurrence. The consistent findings of a haemarth-rosis, Bankart lesion and robust tissue provide theideal setting for surgical repair. Early open or arthro-scopic surgical stabilisation of the avulsed capsulo-labral complex has provided encouraging resultsand significantly reduced the risk of recurrent in-stability. However, surgical selection is exceedinglyimportant. Candidates for surgical managementshould be athletes who: (i) are younger than 25years of age; (ii) have sustained a dislocation thatrequired a reduction; and (iii) have no associatedneurological injury or greater tuberosity fracture.Other candidates for surgery in the acute settinginclude those with irreducible dislocations, displacedproximal humerus fractures or scapular fractures

a

b

Fig. 2. (Top ) Arthroscopic view from the posterior portal in a leftshoulder showing a Perthes-Bankart lesion. The photo is ori-ented for the sitting position. The probe is within the intervalbetween the glenoid rim and capsulolabral complex, showingseparation of the labrum and capsule from the glenoid rim andscapular neck. (Bottom ) Arthroscopic view from the posteriorportal in a different left shoulder with an intact capsulolabralcomplex. The labrum is firmly affixed to the glenoid rim. Theprobe is demonstrating an intact inferior glenohumeral ligament.

212 Warme et al.


with 5mm of glenoid articular incongruity or in-volvement of 20 to 25% of the anterior rim.[17,18]

1.4.3 The In-Season AthleteManagement of the symptomatic unstable

shoulder during the season remains a challenge.After a shoulder dislocation or subluxation, manyathletes want to resume play as soon as possible.If, after discussing the treatment options followingan injury, the athlete decides to attempt an earlyreturn to sports, the non-operative rehabilitationprogramme discussed above is initiated. The ath-lete is allowed to return to practice when range ofmotion is pain-free and strength in the affected sidereaches 90% of the uninvolved arm. When resum-ing contact drills, the athlete wears a brace thatlimits external rotation and abduction. Severalover-the-counter braces or harnesses are available,although no cadaveric or biomechanical studieshave evaluated their effectiveness. No braces arecurrently available for athletes with posterior ormultidirectional instabilities.

2. Acute Anterior Subluxations

Unlike an acute anterior dislocation, acute sub-luxation of an athlete’s shoulder can be difficult todiagnose by history alone. The mechanism is sim-ilar; usually a traumatic injury with the shoulderabducted and externally rotated or in a hyper-extended position. Missed punches are also a fre-quent mechanism of injury in boxing. The athlete’scomplaints may be vague and it may be difficult toassess increased humeral head translation on phys-ical examination. Collision athletes may complainof ‘stinger’-type symptoms, which has led to theterm ‘dead arm syndrome’for anterior subluxation.

On physical examination, there may be tender-ness to palpation on the posterior glenohumeral jointline. The apprehension test can be positive or maycause pain (usually posteriorly) which is decreasedwith a relocation manoeuvre. Impingement signsmay also be positive; however, impingement is al-most always secondary to the glenohumeral insta-bility in a young athlete. Increased translation toload-shift testing may be difficult to detect, espe-cially when the shoulder is acutely injured. Occa-

sionally, crepitation can be appreciated with theanterior load-shift suggesting a labral tear. Repeatexaminations after the shoulder ‘cools down’ maybe helpful. Radiographs, including anteroposterior,West Point and Stryker notch views, may aid in thediagnosis if glenoid rim calcifications or fractures,or posterior humeral head impression fractures(Hill-Sachs lesions) are present.

Treatment for initial anterior subluxation includesimmobilisation, activity restriction and a structured,comprehensive shoulder rehabilitation programme,as described in section 1.4.1. Sports-specific exer-cises, plyometrics and muscle endurance exercisesare added later. The athlete can return to sport whensymptoms resolve and strength returns to normal.Patients who fail to improve or who have recurrent

Fig. 3. Arthroscopic view from the anterior superior portal in aright shoulder showing reapproximation of the capsulolabralcomplex to the glenoid rim with 2 bioabsorbable tacks.



subluxation events may be candidates for operativetreatment.

3. Recurrent Anterior Instability

The evaluation and treatment of true recurrentanterior shoulder instability is relatively straight-forward. The problem arises when athletes presentwith atypical shoulder instability complaints,which is not unusual. The principles of evaluationinclude determining (i) the direction of instabilityand (ii) where the instability pattern lies within thespectrum between atraumatic and traumatic. These2 principles will help determine the pathologicalanatomy associated with the patient’s instabilitycomplaints. The guiding principle in shoulder in-stability surgery should be to attempt to restore theanatomy to normal. Determining the direction andtraumatic shoulder history will greatly assist in de-termining which patients are surgical candidates,and the appropriate operative approach in surgicalpatients.

In theory, this approach appears easy; however,shoulder instability can present anywhere along acontinuous spectrum of pathology, and it is there-fore often difficult to classify a shoulder instabilityas purely anterior or traumatic. There may be fea-tures of several different instability patterns makingevaluation difficult and confusing. Patients with re-current anterior instability may have different aeti-ologies and traumatic forces associated with pre-vious injuries. In addition, these patients may havevarying degrees of inherent or acquired ligamen-tous laxity. Therefore, the pathological anatomy maydiffer from case to case, and treatment should betailored to correct these anatomic changes.

3.1 History and Physical Examination

History and physical examination remain the keyevaluation tools for the patient with recurrent ante-rior instability. Recurrent, traumatic anterior insta-bility is a diagnosis that can be obvious on historyand physical examination. Usually, the patient willhave had a dislocation followed by other shoulderdislocations or subluxations. In this type of anteriorinstability, patients can usually provide a clear his-

tory of the problem. The following questions shouldguide one toward the appropriate instability classi-fication:• What was the extent of the force involved in the

initial or subsequent dislocations? A history ofcollision sport or high energy trauma suggeststraumatic instability.

• Did the dislocation require a manual reduction?If yes, a traumatic aetiology is more likely.

• How long did it take to recover from the firstdislocation? It usually takes several weeks torecover from a true, traumatic anterior dislocation.

• Which direction did the shoulder dislocate? Oc-casionally the patient will not be able to providethis information, but when he or she clearly knowsthe answer, this question can solve the directiondilemma, especially if injury radiographs areavailable.Physical examination findings associated with

recurrent, traumatic anterior instability will include apositive apprehension test and, in the relaxed pa-tient, an increase in anterior translation of the hu-meral head from the normal, uninjured side on theload-shift test. An anterior glenoid rim fracture orcalcifications on the West Point view help to con-firm the diagnosis of traumatic anterior instability.In this class of patients, pathological anatomy fre-quently includes capsulolabral avulsions (Perthes-Bankart lesions) and posterolateral humeral headimpression fractures (Hill-Sachs lesions).

Another frequent presentation of anterior insta-bility is the patient with recurrent subluxation whodescribes the ‘dead arm syndrome’, as mentionedin section 2. In recurrent subluxation, the recurrentinstability can result from injuries anywhere alongthe atraumatic to traumatic spectrum. The questionslisted above will help classify the direction of in-stability and where the instability pattern lies onthe atraumatic to traumatic spectrum; however,compared with a patient with recurrent dislocation,it will be more difficult to classify patients withrecurrent subluxations.

Patients with recurrent subluxations may not ap-preciate overt instability, and may complain onlyof shoulder pain, which is frequently localised to

214 Warme et al.


the posterior shoulder. They may complain of par-aesthesias or a sensation of total weakness of theaffected arm after each traumatic episode. Frankdislocation may not occur, and often a collisionathlete describes the episode as a ‘stinger’ or givesa history suggestive of a neurological injury. Phys-ical examination findings may be similar to thoseof recurrent dislocations, but are often more subtle.Findings consistent with impingement syndromesecondary to the shoulder instability are common.Radiographs may be helpful if they show anteriorrim calcifications, glenoid rim fractures or humeralhead impression fractures. Awide spectrum of patho-logical anatomy may be associated with recurrentsubluxation. Perthes-Bankart lesions, labral tears,capsular attenuation/injury, partial cuff tears andHill-Sachs lesions can be observed.

Many athletes with shoulder complaints will havegeneralised shoulder laxity, making the evaluationeven more difficult. Swimmers, gymnasts and otherathletes who require wide ranges of motion andsubject their shoulders to repetitive microtraumaoften have increased glenohumeral translation. Iftheir shoulder complaints are secondary to insta-bility, their answers to the questions listed abovewill usually guide the examiner to an atraumaticinstability pattern. The patient usually describes thetrauma associated with the initial event as minor.Spontaneous reductions are common, and disabilityis short. Although often classified as multidirectionalinstability, when symptomatic, shoulders with gen-eralised laxity will usually be symptomatic in pri-marily one direction, most often anteriorly.

Like subluxation patients, these patients may denyinstability and complain of posterior shoulder painor pain that is more global. Paraesthesias into theaffected arm and pain or ‘looseness’ with carryingluggage or heavy objects is a frequent complaint.These patients may have no true apprehension test,but an obvious sulcus sign is typically present. Ex-cessive glenohumeral translation in multiple direc-tions may be present in both the injured and unin-jured shoulder. Anterior load-shift testing often willbe painful, reproducing the patient’s symptoms.Other features of hyperlaxity (metacarpophalangeal

joint hyperextension, elbow hyperextension, kneerecurvatum, etc.) are commonly noted. Radiographsare usually normal. Capsular attenuation or redun-dancy is the hallmark pathological finding in thisatraumatic type of instability.

The throwing athlete deserves special consider-ation. Throwers with instability may complain ofposterior shoulder pain, and have impingement signsor other rotator cuff-related findings. Instabilitycomplaints in these patients are infrequent; painpredominates.

Typically, throwers have excessive external ro-tation accompanied by an adaptive loss of internalrotation. These patients may develop anterior insta-bility because of excessive posterior capsular tight-ness, rotator cuff dysfunction or repetitive micro-trauma to the anterior inferior capsuloligamentousstructures involved in the overhead motion. Varyingdegrees of joint laxity may be present. Again, radio-graphs may be helpful if they show anterior rimcalcifications, glenoid rim fractures or humeral headimpression fractures. Pathological anatomy varies,and can include superior labrum anterior-posteriorlesions, Bankart lesions, articular surface abnor-malities, partial cuff tears and capsular redundancyor attenuation.

Another emerging group of athletes is the middle-aged (older than 40 years) recreational athlete. Re-current instability after traumatic dislocation in thispopulation is less common, occurring at a rate ofapproximately 10 to 15%; however, concomitantinjuries to the rotator cuff increase with increasingage. The middle-aged patient who complains ofpersistent disability after traumatic dislocationshould be evaluated for suspected cuff pathologyor injury to the axillary/suprascapular nerves. A re-cent study in middle-aged patients (> 40 years old)found a high correlation with recurrent anterior in-stability and subscapularis tendon ruptures. Weak-ness of internal rotation and an abnormal lift-offtest should arouse suspicion for this diagnosis.[19]

3.2 Additional Evaluation Techniques

In most cases, history, physical examination andplain radiographs should lead to the proper diag-



nosis. Occasionally, determining the appropriatediagnosis may be difficult, especially in the patientwith generalised laxity or in the throwing athletewhere pain is the predominant symptom. In thesecases, there may be overlapping symptoms whichmay indicate secondary impingement or cuff pa-thology. Selective subacromial injections and in-jections of the acromioclavicular joint and, on rareoccasions, the glenohumeral joint may be helpful.A local anaesthetic such as 1% lidocaine injectedselectively on different visits with repeated impinge-ment or provocative tests can help separate trueimpingement from secondary impingement due toanterior instability.

Magnetic resonance imaging (MRI) can also bea useful adjunct. A recent study compared contrast-enhanced MRI (100% sensitivity, specificity andaccuracy) with computed tomography arthrography(90% sensitivity, 100% specificity and 91% accu-racy) when correlated with arthroscopy.[20] Thisstudy technique permitted diagnosis of anteroinferiorlabral tears, previously a difficult area to image andinterpret. However, the MRI is heavily dependenton technique and expert interpretation. In youngathletes, especially throwers, the difficulty with spec-ificity regarding rotator cuff pathology may be mis-leading. We would reserve this imaging modality

for only the most difficult of cases and discourageits routine use.

Occasionally, an examination under anaesthesia(EUA) and diagnostic arthroscopy will be neces-sary to confirm the diagnosis of anterior instability.The EUA should involve an assessment of gleno-humeral translation in the anterior, posterior andinferior directions. The examination should empha-sise testing at 80 to 90° abduction in the plane ofthe scapula in neutral, internal and external rotation(fig. 4). We use the load-shift method of testing andrecord translation as: (i) trace; (ii) 1+ humeral headtranslates to rim of glenoid; (iii) 2+ humeral headtranslates over rim but reduces when load removed;and (iv) 3+ humeral head translates over rim andremains dislocated when load removed (fig. 5).[21]

All testing should be compared with the oppositeshoulder.

Increased glenohumeral translation, coupled withthe arthroscopic findings of anterior capsulolabraldetachment, capsular injury and damage to the ar-ticular surface of the posterior humeral head,correlate with the diagnosis of anterior instability.In cases of suspected traumatic, anterior instabilitythat do not have anterior capsulolabral changes, itis important to examine the axillary pouch for ahumeral avulsion of the IGHL, the so called ‘HAGLlesion’ (humeral avulsion of the glenohumeral lig-ament). The humeral-side avulsion of the IGHL maybe present in up to 9% of cases of anterior instabil-ity.[22]

Many patients with traumatic recurrent anteriorinstability will have capsular laxity as an importantcomponent for the instability. There may be noBankart lesion in these cases, but the capsular lax-ity occurs secondary to repetitive stretching or inter-stitial injury to the IGHL complex. Overhead ath-letes are less likely to have complete anterior labraldetachments and the arthroscopic findings maydemonstrate anterior or posterior labral fraying, re-dundant anteroinferior capsule, superior labral tearsand articular surface partial rotator cuff tears. Theinternal impingement phenomenon as described byJobe may also be present, especially in throwers.[23]

Fig. 4. Examination under anaesthesia. The surgeon is perform-ing an anterior load-shift test in the plane of the scapula with theshoulder externally rotated. This test is also performed with theshoulder in neutral rotation and internal rotation.

216 Warme et al.


3.3 Treatment

Treatment of shoulder instability depends on thepathological anatomy present, and the pathologyusually correlates with the direction and traumaticpattern of the instability. Generally, multidirectionaland atraumatic patterns can be successfully treatednon-operatively with a focused shoulder rehabili-tation programme. Similarly, posterior instabilitycan frequently improve with rehabilitation, espe-cially when the instability is secondary to repetitivetrauma.

In recurrent, traumatic anterior instability, thepathological anatomy is remarkably consistent. ThePerthes-Bankart lesion is found in almost all cases,and is probably the lesion that puts the shoulder atrisk for recurrent dislocation or subluxation. Witheach dislocation there is likely injury to the capsulo-ligamentous structures, which further damages thestatic restraints of the shoulder. Similar findingscan be present in recurrent posterior instability thatis secondary to a significant traumatic event.

In these traumatic cases, attempts to restore theshoulder anatomy through surgery provide the mostreliable method for elimination instability com-plaints. In true recurrent, traumatic anterior insta-bility the success rates of non-operative treatmentare low. However, a rehabilitation programme cansometimes eliminate the need for surgery. There-fore, if not previously attempted, a programme tostrengthen the dynamic stabilisers as described insection 1.4.1 should be included in the first step oftreatment.

Indications for surgical stabilisation include re-current dislocation/subluxation, pain and functionaldisability despite rehabilitation and modificationof activity. Obviously, many athletes are unwillingto modify sports participation. In addition, patientswho have recurrent symptoms with activities ofdaily living warrant surgical consideration. Surgi-cal treatment includes a myriad of approaches andtechniques. The most popular approaches are theopen and arthroscopic technique.

3.3.1 Open Stabilisation TechniquesOperative treatment for recurrent, traumatic an-

terior instability of the shoulder should be tailoredto the pathology encountered and the vocationalpursuits of the patient. The procedure of choice iscurrently a modification of the original Bankartprocedure with direct repair of the capsulolabralcomplex to the glenoid rim and a capsulorrhaphy,as needed, to address capsular redundancy. The useof suture anchors has facilitated these open Bankartrepairs. Care must be taken to properly place theseanchors. Medial placement of suture anchors canlead to residual instability.[24]

The open Bankart procedure has withstood thetest of time. In a current long term report,[25] 56patients were evaluated at a mean 12 years after theBankart procedure.The mean loss of external rotationwas 12° and 52 patients (92%) rated the shouldergood or excellent. The re-dislocation rate was 5%.

Other open reconstructive procedures havebeen reported to successfully treat recurrent ante-rior instability, and many of these procedures haveutilised a non-anatomic approach. Specifically, the

Trace 2+

1+ 3+

Fig. 5. Grading of the load-shift test. Grade 2 is differentiatedfrom Grade 3 by spontaneous reduction of the shoulder afterremoval of load.[21]



Magnuson-Stack and Putti-Platt procedures shortenthe capsule and subscapularis, resulting in a loss ofexternal rotation and sometimes strength. Thesemethods have been fairly successful in preventingre-dislocation (10 to 25% failure rate).[26,27] How-ever, surgical treatment should also include evalu-ation for recurrent subluxation, a critical review offunction, and ability to return to pre-injury athleticlevel. Loss of external rotation[28] can be function-ally disabling for the throwing athlete and can leadto osteoarthritis of the glenohumeral joint.[29,30]

Rarely, patients with recurrent anterior instabil-ity following minimal trauma or from repetitivemicrotrauma will require operative treatment. Inthese cases, the Perthes-Bankart lesion is frequentlyabsent, and a capsulorrhaphy is appropriate to ad-dress capsular attenuation as the likely site of patho-logy. This may include a formal anteroinferior cap-sular shift in patients with multidirectional instability.

Capsulorrhaphies can be accomplished in a vari-ety of ways. The ‘T’ capsulorrhaphy is perhaps themost common method and permits the surgeon theability to re-tension the capsule in both the medial-lateral and inferior-superior directions. There hasbeen a recent report of selective capsular repairwhere the inferior and superior portions of the cap-sule are tensioned with the arm in different posi-tions, which has minimised loss of motion.[31]

Another method of capsulorrhaphy which canbe used, with or without Bankart repair, requiresvertical capsulotomy halfway between the glenoidand humeral neck. The medial leaf is shifted supero-laterally and then the medial edge of the lateral leafis shifted superomedially. A series of 142 shouldersoperated with this technique was recently reported.With an average follow-up of 5 years, 93% wererated as good or excellent. This procedure was ef-fective for patients with recurrent traumatic insta-bility, atraumatic instability, and for revision.[32]

In one series of throwers an anterior capsulolabralreconstruction has been described[33]. In an effortto preserve the subscapularis, this structure is splitand the capsule and labrum are shifted on the gle-noid side. This has the theoretical advantage of re-storing stability and preserving motion. In patients

with anterior instability, a sulcus sign and no Bank-art lesion, closure of the rotator cuff interval, espe-cially if large, is also important.

3.3.2 Arthroscopic Stabilisation TechniquesArthroscopic stabilisation techniques have flour-

ished in the past decade. The most popular tech-niques have included transglenoid suture repair, bio-absorbable tack stabilisation and suture anchormethods. A critical review of short and mid termfollow-up studies reveals an increased rate of re-currence with the arthroscopic method. Failure rateshave been reported from 0 to 45%, depending onthe investigator.[15,34-43] Despite the higher failurerate, arthroscopic stabilisation is popular and isgaining interest because of several advantages.Firstly, when retention of motion is critical to theathlete’s performance, the arthroscopic techniquehas the advantage of eliminating the need for softtissue dissection, especially detachment and re-attachment of the subscapularis tendon. Secondly,morbidity associated with arthroscopic repair isgreatly reduced over open procedures. Arthroscopicstabilisation has been associated with a 1.8-fold de-crease in operative time, a 10-fold decrease in bloodloss and a 2.5-fold reduction in narcotic use.[44]

Length of hospitalisation and time lost from workhave also favoured arthroscopic over open tech-niques.

Arthroscopic techniques have advanced to ap-proaching the capabilities of open Bankart repairs.Techniques utilising suture anchors, closure of therotator interval and mobilisation of the IGHL haveall been developed. In a recent study of arthro-scopic Bankart repairs in a high-risk population, 37of 40 patients remained stable at an average follow-up of 30 months.[45]

Perhaps the newest technique to address theproblem of capsular laxity is the use of laser orradiofrequency waves to generate heat and ‘shrink’the capsule. This is an extremely attractive idea asa small probe can be inserted arthroscopically, whichavoids the technical demands of placing metallicsuture anchors and tying knots arthroscopically.Although preliminary results are encouraging,there are no human data defining the biological and

218 Warme et al.


biomechanical end-result of heat-shrinking connec-tive tissue. Animal studies have shown that thermalexposure of capsular tissue causes collagen fibredenaturation which is time and temperature de-pendent. Shrinkage of capsular tissue to 50% of theinitial length occurs with exposures of 1 minute at65°C.[46] However, significant decreases in tensileproperties have been seen on mechanical test-ing.[47,48] Further studies are needed before wide-spread use of electrothermal capsular shrinkage canbe recommended.

Although arthroscopic stabilisation proceduresare attractive from many perspectives, the techniquehas reported results that are inferior to the openmethod. Patient selection remains critical to ap-proach the results of the open method. If the surgeonchooses this method, the patient profile should in-clude: (i) a traumatic origin for the instability; (ii)unidirectional instability; (iii) no features of liga-mentous laxity; (iv) less than 5 episodes of insta-bility; (v) robust capsulolabral tissue at arthroscopy;and (vi) non-contact sport requirement. The tech-nique should have the ability to address mild cap-sular redundancy to improveresults. As the techniqueimproves and surgeons gain experience, the resultsof arthroscopic procedures for treating recurrentanterior instability may approach those of openprocedures.

3.3.3 ComplicationsAs with any procedure, complications after both

arthroscopic and open stabilisations do occur, andsome are procedure specific. Recurrent instabilityis perhaps the most common complication and istypically a result of failure to repair the Bankartlesion or to address residual capsular laxity.

Other causes of failure include loss of motion,glenohumeral arthritis secondary to loss of motion,loose or painful hardware and neurovascular injury.Subscapularis rupture or deficiency has been re-ported after open Bankart repair. This complicationshould be suspected in the patient who complainsof instability with normal glenohumeral translationon examination and a positive lift-off sign.[19,49]

Successful results have been reported from promptrepair of the subscapularis tendon. In chronic sub-

scapularis ruptures, transferring the upper portionof the pectoralis major tendon to reconstruct thesubscapularis has provided satisfactory results.[50]

4. Conclusion

In summary,an anatomical approach to the eval-uation and treatment of recurrent anterior instabilitywill lead to high success rates in the vast majorityof athletes. Improved understanding of the epidem-iology and pathology of anterior shoulder instabilityin young athletes has resulted in a trend towardearly surgical treatment and an increased use ofarthroscopic techniques.

Acknowledgements

The opinions and assertions contained herein are theprivate views of the authors and are not to be construed asofficial nor do they reflect the views of the United StatesDepartment of the Army or the United States Department ofDefence.

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Anterior Shoulder Instability in Sport Current Management Recommendations (1)