2019 ASES SPECIALTY D

AY MEETING ABSTRACTS

Paper #1 * POSTOPERATIVE RECOVERY

COMPARISONS OF LATISSIMUS DORSI TRANSFERTO LOWER TRAPEZIUS TRANSFER FOR THETREATMENT OF MASSIVE ROTATOR CUFF TEARS Jarret M. Woodmass, MDb, Eric R. Wagner, MDa, MichelleJ. Chang, BSb, Kathryn M. Welp, MSa, Laurence D. Higgins, MDMBAb, Jon J.P. Warner, MDb, a Emory University, Department ofOrthopedic Surgery, Atlanta, GA, USA; bHarvard University,Boston Shoulder Institute, Boston, MA, USA

Background: Massive irreparable posterosuperior rotator cufftears pose a challenging problem and the optimal treatment remainscontroversial. In younger patients with external rotation lag signs, dy-namic reconstruction using a tendon transfer is preferred. Open Latis-simus dorsi (LD) tendon transfer has demonstrated excellent long-termoutcomes while arthroscopic techniques have demonstrated reliableshort-term outcomes. In recent years, arthroscopic lower trapezius(LT) tendon transfer has been described but no clinical outcomeshave been reported to date. The purpose of this study is to comparethe early post-operative recovery following open and arthroscopicLD transfer to arthroscopic LT tendon transfer for patients with massiveirreparable posterosuperior rotator cuff pathology.

Methods: A multicenter retrospective analysis comparing thepost-operative recovery outcomes after either an open or arthroscopicLD transfer and arthroscopic LT transfers by one of two high volume,fellowship trained surgeons was performed. Patients were includedwho had a minimum of 6 months follow-up. Preoperative and postop-erative (2weeks, 6weeks, 3months, 6months, 1 year and 2 year) timepoints were evaluated. Outcomes measures included Visual AnalogPain Scale (VAS), American Shoulder and Elbow Surgeons (ASES)Shoulder Function Score, ASES Shoulder Index Score and SANEScore. Overall, 12 patients underwent open LD transfer (9 male, 3 fe-male), 16 underwent arthroscopic LD transfer (13 male, 3 female) and8 underwent an arthroscopic LT transfer (5 male, 3 female). The meanage for open LD, arthroscopic LD, and arthroscopic LTwas 56.5, 56.9,and 53.3, respectively. The mean duration of follow-up for open LD,arthroscopic LD, and arthroscopic LTwas 17.7, 7.9, and 11.3 months,respectively. The overall duration of follow-up was 12 months.

*Indicates paper nominated for the Neer Award

Results: The postoperative recovery curves are displayed in Figure1.Arthroscopic LD and LT transfers had significantly improvedpost-oper-ative forward flexion (p<0.04) and external rotation (p<0.0001) whileopen LD transfer had significantly improved external rotation(p¼0.0034). Arthroscopic LD and LT transfers had significantly reducedpain scores starting at 6 months (p¼0.03 p¼0.05) with open LD startingat one year (p¼0.008) when compared to pre-operative measurements.Arthroscopic LD and LT transfers improved ASES Shoulder Functionscores starting at one year (p<0.03). Arthroscopic LD, open LD, andarthroscopic LT had significantly improved SANE scores at 1 year(p<0.01). In comparing the post-operative outcomes, arthroscopic LTdemonstrated significantly improvedASES shoulder indexandVASwhilearthroscopic LD transfer had improvedASES shoulder index compared toOpen LD at 1 year (p<0.03). There was a total of 4 (11.4%) complica-tions. These includedan infection forP. acnesandanaxillary nerve injuryfor arthroscopic LD transfers as well as a complex regional pain syn-drome and a post-surgical adhesive capsulitis for open LD transfers.

Conclusions: Open latissimus dorsi, arthroscopic latissimusdorsi and arthroscopic lower trapezius transfer all provided significantimprovement in pain and function at short-term follow-up. Arthro-scopic LT tendon transfer provided earlier improvements in pain andsustained improvements in function when compared to open LD trans-fer and equivalencewhen compared to arthroscopic LD transfer.Whilethis study is limited in its sample size it demonstrates promising earlyoutcomes and safety for lower trapezius transfer. Further comparativestudies are needed to evaluate the optimal conditions for using each ofthese treatments in the management of massive rotator cuff pathology.

Paper #2 OUTCOME OF ARTHROSCOPICALLYASSISTED LOWER TRAPEZIUS TRANSFER TORECONSTRUCT MASSIVE IRREPARABLEPOSTERIOR-SUPERIOR ROTATOR CUFF TEARS

Bassem T. Elhassan, MDa, Eric R. Wagner, MD, MScb,Joaquin Sanchez-Sotelo, MDa, aMayo Clinic, Rochester, MN, USA;b Emory University, Atlanta, GA, USA

Background: Reasonable outcomes has been reported with in-direct open lower trapezius transfer extended with an Achilles

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e280 2019 ASES Specialty Day Meeting Abstracts J Shoulder Elbow Surg2019

tendon allograft to reconstruct irreparable posterior-superior rotatorcuff tears. Techniques have been developed to perform this proced-ure arthroscopically. However, the outcome of arthroscopically assis-ted lower trapezius transfer is largely unknown. The purpose of thisstudy is to report the outcome of arthroscopically assisted lowertrapezius transfer to reconstruct irreparable posterior-superior rota-tor cuff tear.

Methods: Forty-one consecutive patients with irreparable poste-rior-superior rotator cuff tears who underwent an arthroscopically as-sisted transfer of the lower trapezius transfer were included in thisstudy. There was an associated repairable tear of the subscapularistendon in 25 shoulders. The average age of the patients was 52(range, 37-71) years and average follow-up was 13 months (range,6-17 months). Nineteen patients had true pseudoparalysis of theshoulder on preoperative examination. Outcome measures includedvisual pain analogue score (VAS), range of motion (ROM), subjectiveshoulder value (SSV), and Disabilities of the Arm, Shoulder and Hand(DASH) score.

Results: Thirty-seven patients had significant improvement of alloutcome scores: VAS, SSVand DASH. At most recent follow-up, rangeof motion averaged: 133o flexion, 95o abduction, and 47o externalrotation. Outcomewas not affected by the presence of a subscapularistear. However, three patients who had preoperative arthritic changesof the shoulder, 2 with Hamada 2 and one Hamada 3, had persistentpain and limited range of motion of the shoulder after surgery, and 2of them underwent reverse shoulder arthroplasty. One patient had sig-nificant improvement of pain but with no improvement of motion, andelected not to have further surgery. Two additional patients had a trau-matic rupture of the transfer as result of fall (at 5 and 8 months postop). One underwent revision arthroscopic repair and did well aftersurgery, and the other had good pain relief but recurrent weaknessand limited range of motion, and elected not to have a revision sur-gery.

Conclusions: Arthroscopic assisted lower trapezius transfermay lead to a good outcome in patients with massive irreparable pos-terior-superior rotator cuff tears, including patients with pseudoparal-ysis. The presence of an associated reparable subscapularis tear didnot affect the outcome. However, the presence of radiographic degen-erative changes did lead to a worse outcome and the need for revisionto reverse shoulder arthroplasty.

Paper #3 * LATARJET PROCEDURE VERSUSILIAC-CREST BONE GRAFT TRANSFER FORTREATMENT OF ANTERIOR SHOULDERINSTABILITY WITH GLENOID BONE LOSS: APROSPECTIVE RANDOMIZED TRIAL

Philipp Moroder, MDa, Eva Schulz, MDb, Guido Wierer, MDb,Alexander Auffarth, MDb, Peter Habermeyer, MDc,Herbert Resch, MDb, Mark Tauber, MDc, a Center forMusculoskeletal Surgery, Campus Virchow, Charit�e-Universitaetsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin,Germany; b Department of Traumatology and Sports Injuries,Paracelsus Medical University, Strubergasse 21, 5020 Salzburg,Austria; c Department of Shoulder and Elbow Surgery, ATOS ClinicMunich, Effnerstrasse 38, 81925 Munich, Germany

Introduction: The Latarjet and iliac-crest bone graft transfer(ICBGT) procedure are competing treatment options for anteriorshoulder instability with glenoid bone loss. Despite the fact that severalclinical, radiological, and biomechanical studies have shown both theadvantages and disadvantages for either technique no prospectiverandomized clincial outcome trials are currently available. Goal ofthis study was to compare the clincial and radiological outcome of

*Indicates paper nominated for the Neer Award

the Latarjet and the ICBGT procedure by means of a prospective ran-domized trial. The hypothesis of this study was that the Latarjet andICBGT procedure for treatment of anterior shoulder instability withglenoid bone loss provide the same clinical and radiological outcome.

Methods: In a bi-centric prospective randomized study 60 pa-tients with anterior shoulder instability and glenoid bone loss wereincluded and randomly allocated with a 1:1 ratio to either an open La-tarjet or open ICBGT procedure. Surgeries were performed by twoexperienced surgeons at each center with experience in both tech-niques. Exclusion criteria were unwillingness to participate in therandomization process, pre-existing ipsilateral shoulder pathology,previous ipsilateral shoulder surgery except open or arthroscopicBankart repair, previous infection, neuro-muscular disease, lack ofcompliance, problems with attending the regular follow-ups, andchronic alcohol or drug abuse. Clinical evaluation was completedbefore surgery as well as 6, 12, and 24months after surgery includingtheWestern Ontario Shoulder Instability Index (WOSI; main outcomemeasurement), Rowe Score, Subjective Shoulder Value (SSV), painlevel, satisfaction level, work and sports impairment as well as assess-ment of instability, range of motion and strength. Additionally, adverseevents were prospectively recorded. Radiographic evaluationincluded preoperative, postoperative, and follow-up CT scans with3D reconstruction used for longitudinal evaluation of the changes ofglenoid diameter, area, depth, and version as well as the glenoidtrack. The final follow-up rate was 90.0%. Power analysis and onlinetrial registration were accomplished prior to the beginning of the studyand approval of the local ethical committees was obtained.

Results: The WOSI, Rowe Score, SSV, satisfaction level, painlevel, work and sports impairment showed no significant differencebetween both groups (p>0.05). Range of motion showed no signifi-cant difference except for significantly diminished internal rotationin the Latarjet group at every follow-up time-point (p<0.05). Strengthin abduction, internal rotation, and external rotation showed no signif-icant difference between both groups (p>0.05). No dislocation wasrecorded after either type of surgery within the monitored time period.Two patients in the ICBGTand one patient in the Latarjet group expe-rienced a single postoperative traumatic subluxation event. Complica-tions in the ICBGT group included eight paresthesias and two cases ofsuperficial wound infection at the donor site, as well as one graft frac-ture one year after surgery due to a bycicle fall with subsequent graftre-union and without residual subjective or objective instability. Com-plications in the Latarjet group included one pseudoarthrosis of thegraft without clinical consequence, one case of screw irritationrequiring revision surgery, and one case of postoperative hematoma.The CTscan analysis revealed a larger glenoid augmentation effect ofthe ICBGT which, however, was attenuated at follow-up due to bonyremodeling.

Conclusion: The Latarjet and ICBGT procedure for treatment ofanterior shoulder instability with glenoid bone loss showed no differ-ence in the clinical and radiological outcome except for a significantlyworse internal rotation capacity in the Latarjet group and frequentlynoted donor site sensory disturbances in the ICBGT group.

Paper #4 CLINICAL AND RADIOLOGICALOUTCOMES AFTER ARTHROSCOPIC BANKARTREPAIR USING THE ALL-SUTURE ANCHORS:COMPARISON WITH THE BIODEGRADABLESUTURE ANCHORS

Sang-Jin Shin, MDa, Jae-Hoo Lee, MDb, In Parka, Jun-Seok Kanga, Yoon-Geol Joa, a Department of Orthopedic Surgery,College of Medicine, Ewha Womans University Seoul Hospital,Seoul, Republic of Korea; b Department of Orthopaedic Surgery,Inje University, Ilsan Paik Hospital, Seoul, Republic of Korea

Purpose: An all-suture anchor has been introduced to make itpossible to place anchors with a smaller diameter, which allows to pre-serve more glenoid bone. Moreover, due to the softness of all-sutureanchor, the curved guide for predrilling and anchor insertion is avail-able and allowing the surgeons to maintain acceptable angle of

J Shoulder Elbow Surg 2019 ASES Specialty Day Meeting Abstracts e281Volume 28, Number 8

anchor insertion into the inferior part of glenoid during arthroscopiclabral surgery. The purpose of this study was to compare the clinicaloutcomes and radiological findings at the anchor site after arthro-scopic Bankart repair with conventional biodegradable suture an-chors and all-suture anchors.

Material andMethod:A total of 67 patients were enrolled: 33underwent surgery with an 1.3-mm (single loaded) or 1.8-mm (dou-ble loaded) all-suture anchor (Group A), and 34 underwent surgerywith a 3.0-mm biodegradable anchor (10.8mm in length, 30%TCP/70% PLGA) (Group B). The inclusion criteria were patients withan isolated Bankart lesion in arthroscopic examination after anteriorshoulder dislocation. Clinical outcomes, including the Rowe score,ASES score, return to preinjury sports level and redislocation rateswere evaluated at 2 years after surgery. The degree of tunnel enlarge-ment of the suture anchor insertion site was assessed with postopera-tive CTand CTarthrography at 1 year after operation according to thetype and size of the suture anchor. To define the width of the tunnel, thegreatest width of the hole along the suture anchor among the axial,sagittal, and oblique coronal planes was determined. Tunnel enlarge-ment was calculated based on the difference between the width of thehole and the width of the suture anchor.

Results: Clinical outcomes did not differ significantly betweengroups A and B (ASES; Group A, 88.5 6 12.3; Group B, 89.7 610.9, P¼0.667, Rowe score; Group A, 87.9 6 14.9; Group B,88.5 6 14.6, P¼0.857). The proportion of patients who returned totheir preinjury level of sports at 2 years after operation was 81.8%in group A and 85.7% in group B. The postoperative redislocationoccurred in two patients in group A (6.1%) and group B (5.9%.P¼0.682), respectively. Total number of suture anchors inserted intothe glenoid was significantly higher in group A (4.5 6 0.9) than ingroup B (3.9 6 0.5, P ¼ 0.03). Average enlargement of the tunnelwas significantly greater with the 1.8-mm all-suture anchor(2.860.9mm) than the 1.3-mm all-suture anchor (1.260.8mm) and3.0-mm biodegradable anchor (0.861.2mm) (P<0.001). Enlarge-ment of the tunnel was also significantly greater with the 1.3-mmall-suture anchor than the 3.0-mm biodegradable anchor (P < 0.01).

Conclusion: Despite of technical advantages of all-suture an-chor insertion into the glenoid, the all-suture anchor demonstrated asignificantly smaller load for 2 mm of labral displacement which isknown to be associated with clinical fixation failure. However, anadequate application of upward force to a 6-kg weight deploy theall-suture anchor is regarded as an important factor to eliminate infe-rior fixation stability and early displacement. Despite concerns aboutthe biomechanical results, our clinical outcomes of instability treatmentwith the all-suture anchor were equivalent to those of conventionalbiodegradable anchors. Arthroscopic Bankart repair with the all-su-ture anchor showed comparable clinical outcomes and postoperativestability compared to the biodegradable suture anchor at 2 years aftersurgery. Arthroscopic Bankart repair with the all-suture anchorshowed comparable clinical outcomes and postoperative stability asthe conventional biodegradable suture anchor at 2 years after sur-gery. Tunnel enlargement of the all-suture anchor was significantlygreater than that of the biodegradable suture anchor at 1-year CTanalysis. Although tunnel enlargement was greater with the all-sutureanchor, it did not influence the clinical outcomes.

Paper #5 EFFECT OF THE LOCATION OF THESPLIT OF THE SUBSCAPULARIS ON RANGE OFMOTION, STABILITY, AND CONTACT PRESSURE INTHE GLENOHUMERAL JOINT FOLLOWINGLATARJET OR TRILLAT PROCEDURES

Geoffroy Nourissat, MD, Clinique des Maussins, Paris, FranceAlexander W. Hooke, MA, Andrew Thoreson, Kai-Nan An, PhD,Mayo Clinic, Rochester, Minnesota, USAJean-David Werthel, APHP, Paris, France

Background: Biomechanical effects of the sling position inshoulder stabilizing repairs in not well understood. The purpose ofthis study was to determine the effect of the Latarjet and Trillat proced-

ures on the glenohumeral range of motion, joint stability, and contactpressure as evaluated in a cadaveric model.

Methods: 12 fresh-frozencadaver shoulderswere clearedofall softtissues except for the rotator cuff muscles. The medial scapular body wasremovedand the remainingscapulawaspotted in resin such that the rimofthe glenoid was parallel to the floor. Glenoid length and width weremeasured along the superior-inferior and anterior-posterior axes usinga digital caliper. The humeral shaft was potted in resin in a hollow tubefor fixation to the testing apparatus. The potted bones were then mountedonto a custom testing frame generating anterior humeral translation andjoint compression in the medial direction. Each specimen was tested infive conditions: 1) intact shoulder, 2) 6-mm bony glenoid defect (20%defect) 3) Trillat procedure, 4) Latarjet procedure with subscapularis splitat the junction between its superior 2/3rds and inferior 1/3rd, 5) Latarjetprocedure with subscapularis split at the superior 1/3rds and inferior 2/3rds. A thin film pressure sensor (Tekscan), was placed through a portalcreated on the posterior of the capsule and centered in the joint space,held in place by the compressive forces applied. Internal and externalaxial ranges of motion were measured with the joint positioned in 0�,30� and 60� of glenohumeral abduction (or approximately 30�, 60�and 90� of arm abduction relative to the trunk) measured using a customprotractor fixed to humeral shaft and uniaxial torque cell. The torque cellwas rotated about the humerus’ long axis until a 200 N-mm torque wasreached to determine range ofmotion. Joint stabilitywas assessed in eachcondition by rotating the humerus into the previously determinedmaximum axial internal and external rotation at glenohumeral abductionangles of 0�, 30� and 60�. 50-N of medial compression was applied,and loads of 20 N and 5 N were also applied to the subscapularis andconjoined tendon, respectively, to simulate the sling effect. Starting froma position at which the humeral head was seated at its most medial posi-tion on the glenoid, the humeral headwas translated anteriorly for 10mmat a rate of 2mm/sec. Reaction forces, anterior displacement, and lateralhumeral head displacement data were collected at a sample rate of 100Hz. Glenohumeral contact area and peak pressure were recorded at theend range of internal and external rotation. The stability ratio wascomputed as the ratio of the anterior translational force to the compres-sion force on the joint at maximum displacement at each condition.Means were compared with a full factorial repeated measures ANOVAwith pairwise post hoc comparisons. A Bonferroni correctionwas appliedto account for the multiple comparisons.

Results: Stability ratios were significantly lower with the glenoiddefect compared to the intact and all repaired conditions at all levels ofglenohumeral abduction, but the Trillat and Latarjet repair values werenot significantly different from each other. Internal and external rangesof motion were not significantly different between any condition orglenohumeral angle. While there were no significant differences incontact area at the end range of internal or external rotation betweenany conditions or glenohumeral angles, peak pressure was signifi-cantly lower for the Trillat condition compared to the intact conditionat full external rotation and 0� glenohumeral abduction. Peak externalrotation pressures in the intact condition were also significantly lowerat 30� and 60� glenohumeral abduction compared to 0� abduction.Also peak pressure in internal rotation pressure was significantlylower at 0� glenohumeral abduction compared to 60� abduction.

Conclusions: The location of the subscapularis muscle split in theLatarjet repair does not significantly impact range of internal externalrotation, the contact mechanics at end points of this range, nor the sta-bility. Latarjet and Trillat procedures appear to be comparable proced-ures in these respects as no significant differences in assessmentparameters were observed.

Paper #6 LATERALIZATION ANDATTACHMENTSITE AFFECT SUBSCAPULARIS BIOMECHANICSAFTER REVERSE SHOULDER ARTHROPLASTY

Andreas Kontaxis, PhD, Eric Windsor, James J. Eno, MD,Xiang Chen, MS, David M. Dines, MD, Lawrence Gulotta, MD,Samuel A. Taylor, MD, Hospital for Special Surgery, New York,NY, USA

Figure 1 (A) The NSM, (B) alternative SSc attachment points.

Figure 2 Superior SSc attachment resulted in less adductive (-)moment arms compared to native or inferior insertion.

e282 2019 ASES Specialty Day Meeting Abstracts J Shoulder Elbow Surg2019

Introduction: Reverse shoulder arthroplasty (RSA) is a popularsolution for irreparable rotator cuff tear and cuff tear arthropathy.However, there are still concerns about complications like limitedrange of motion, and stability. The repair of the subscapularis muscle(SSc) in RSA has been debated and recent clinical studies haveshowed that it can decrease shoulder function when used with lateral-ized glenospheres. However, it has been proposed that changing therepair SSc attachment site on the lesser tuberositymay achieve a bettermechanical advantage and improve the function of the muscle. Thepurpose of this study was to investigate how i) RSA glenosphere later-alization and ii) SSc attachment site, can affect its biomechanics.

Figure 3 Glenosphere lateralization can strain the SSccreating passive tension.

Methods: The Newcastle Shoulder Model (NSM) was used tocalculate moment arms and muscle length of the SSc muscle beforeand after virtual RSA. The NSM consists of 6 rigid bones (thorax, clav-icle, scapula, humerus, radius, and ulna) and the model simulatesfunctional shoulder motions including clavicle and scapula kinematics(Fig1.A). The SSc muscle is modelled with 3 lines of action that simu-late the superior, middle and inferior tendon bands. Nine CTs fromhealthy subjects were utilized to customize the NSM and create 9 in-dividual models. Bony geometries were digitized, and the anatomicorigins and insertions of the SSc were identified from an orthopedicsurgeon. A virtual model of a commercially available RSA prosthesis(Comprehensive Reverse Shoulder, ZimmerBiomet) was implanted toeach model. To study the effect of lateralization to the SSc biome-chanics, three lateralized glenospheres (+0, +5 and +10 mm) weretested. Three attachment sites for SSc repair were also simulated foreach model: the native, a superior, and an inferior attachment(Fig1.B). Muscle moment arms and lengths of the SSc were computedthroughout simulations of abduction (0� to 150�), and internal rotation(0� to 80�) at 20� of abduction.

Results: Overall, RSA increased the adduction moment arm ofthe SSc compared to the anatomical shoulder (Fig2). Superior SScattachment resulted in the least adductive moment arm (9.462.2mmcompared to 15.162.8mm and 22.362.9mm for the native and infe-rior attachments respectively, p¼0.002). The superior and nativeattachment had larger rotational moment arm compared to the infe-rior attachment, but it was smaller compared to the anatomical shoul-der (p¼0.003). Glenosphere lateralization did not affect the momentarm results (in abduction or in internal rotation, p¼0.988), but it re-sulted in increased SSc length with maximum average length of

muscle longer than its maximum anatomical values

J Shoulder Elbow Surg 2019 ASES Specialty Day Meeting Abstracts e283Volume 28, Number 8

139.468.4 for +0mm glenosphere, 143.968.4 mm for +5mm and148.469.1mm for +10mm (p<0.01 for all pair comparisons,Fig.3). The inferior attachment also resulted in the significantly longerSSc length (143.968.3 mm, p¼0.001).

Discussion: Lateralization of glenosphere had no effect on SScmoment arms in either abduction or internal rotation. However, it didincrease the length of the muscle more than its anatomical length,which can create a passive tension. The latter in combination withthe adductive moment arm of the SSc after RSA can counteract thedeltoid and weaken shoulder strength. The results of the study sug-gest that a superior attachment site for SSc repair on RSA canimprove SSc function, by decreasing its adductive action and short-ening its length.

Significance: Excessive lateralization should be avoided whenSSc is repaired in RSA. We also suggest a more superior attachmentsite than the native SSc insertion for improving its biomechanical func-tion.

Paper #7 OUTCOMES OF TOTAL SHOULDERARTHROPLASTY FOR INSTABILITY ARTHROPATHYWITH A PRIOR CORACOID TRANSFERPROCEDURE: A RETROSPECTIVE REVIEW ANDCOMPARATIVE COHORT

Michael J. Bender, MDa, Brent J. Morris, MDa, MitziS. Laughlin, PhDb, Aydin Budeyri, MDc, Ryan K. Le, B.S.d, HusseinA. Elkousy, MDa, T. Bradley Edwards, MDa, a Texas OrthopedicHospital, Department Orthopedic Surgery, Houston, Texas, USA;bUniversity of Houston, Health and Human Performance, Houston,Texas, USA; c SANKO University Department of Orthopaedics andTraumatology, Gaziantep, Turkey; d Colorado State University,Greenwood Village, CO, USA

Introduction: As coracoid transfers for shoulder instabilitybecome more prevalent, so will the eventual reconstructions for insta-bility arthropathy that may develop. Concerns exist amongst surgeonsregarding the difficulty and feasibility of performing anatomic totalshoulder arthroplasty for instability arthropathy following these cora-coid transfer procedures. Many question whether the loss of the cora-coid and conjoined tendon as a landmark will increase the rate ofcomplications, and if the splitting of the subscapularis compromisesthe muscle and thereby prohibits the use of an anatomic replacementor could lead to early failures.

Goal: The purpose of this study was to evaluate minimum 2 yearoutcomes following anatomic total shoulder arthroplasty for instabilityarthropathy with a prior coracoid transfer procedure and comparethem to a matched cohort of patients following total shoulder arthro-plasty for primary osteoarthritis.

Methods: A retrospective review was performed on a prospec-tively collected shoulder arthroplasty database from 2004-2018 by asingle surgeon at a high-volume shoulder arthroplasty center. Patientswith a diagnosis of instability arthropathy were identified and a chartreview and radiographic review was performed to identify a subset of14 patients with a prior coracoid transfer (Latarjet or Bristow proced-ure) that underwent subsequent anatomic total shoulder arthroplasty.11 of the patients met criteria for minimum of 2 year clinical follow up,but 1 patient did not have his final follow up data as he was revised fordeep infection to a different implant prior to the 2 year follow up of hisindex procedure. A matched cohort of patients was identified that un-derwent an anatomic total shoulder arthroplasty for primary osteoar-thritis to serve as a comparative group. Cases were matched with 3control subjects utilizing propensity scoring and matching accordingto age, gender, BMI and dominant shoulder with a nearest neighbortechnique utilized for surgery date to account for changes in surgicaltechnique over time. A matched linear, mixed model was used to testfor differences between cases and matched controls for subject char-acteristics, ASES, and SANE scores. Chi-square tests were used toevaluate patient satisfaction.

Results: There were no significant differences between the cora-coid transfer cohort and primary osteoarthritis cohort in regards toage (56.6 6 4.4 vs 56.8 6 5.1) gender (10M:1F vs 30M:3F), BMI(30.1 6 5.6 vs 29.7 6 4.6), shoulder dominance (6 [55%] vs 19[58%]) or final follow up (49.5mo 6 31.2 vs 47.2 6 27.5;p¼0.948). The coracoid transfer cohort had significant improvementin ASES score (436 20.0 to 94.46 4.6; p<0.001), ASES pain score(20.0 6 14.1 to 50.0 6 0; p <0.001), SANE score (31.6 6 19.6 to94.46 6.6; p<0.001), and patient satisfaction (p<0.001). The cora-coid transfer cohort had statistically better final outcome scores thanthe primary osteoarthritis cohort in regards to ASES score(94.464.6 vs 82.26 23.4; p¼0.018), ASES pain score (50.0 60 vs 40.6 6 13.9; p<0.001), and SANE score (94.4 6 6.6 vs 66.86 34.5; p¼0.023). However, these statistical differences in finaloutcome scores are likely not significant as the mean improvementfrom preoperative to postoperative scores were similar between co-horts as the primary osteoarthritis cohort had worse preoperativevalues (ASES score p¼0.373, ASES pain score p¼0.683, SANE scorep¼0.076). There was no significant difference in patient satisfactionbetween the cohorts at final follow up (p¼0.544). The difference inrevision rate (18.2% [2/11] vs 6.1% [2/33]) did not reach statisticalsignificance (p¼0.545).

Conclusions: At early to mid-term follow-up, anatomic totalshoulder arthroplasty performed for instability arthropathy after acoracoid transfer demonstrated good results with significant improve-ments in all outcomemeasures. In this subset of patients, there appearsto be equivalent results to total shoulder arthroplasty performed forprimary osteoarthritis. Longer term follow up of these patients andlarger patient cohorts will provide further insights into this problemand highlight any potential differences in outcomes or revision rate.

TABLESSubject Characteristics at Baseline

Coracoid Transfers Primary OA p

Patients

11 33 Age 56.5 6 4.4 56.8 6 5.1 0.848 Gender (M:F) 30 : 3 10 : 1 >0.99 BMI 30.1 6 5.6 29.7 6 4.6 0.822 Dominant Shoulder 6 (55%) 19 (58%) >0.99 Follow Up (months) 49.5 6 31.2 47.2 6 27.5 0.948

Matched analysis

Coracoid Transfers Primary OA

Preoperative

Postoperative P reoperative P ostoperative

ASES

43.1 6 20.0 94.4 6 4.6 3 6.3 6 15.6 8 2.2 6 23.4 ASES –Pain

20.0 6 14.1

50.0 6 0 8.4 6 5.9 4 0.6 6 13.9

SANE

31.6 6 19.6 94.4 6 6.6 2 8.2 6 23.2 6 6.8 6 34.5

Preop to final FU CCTF vs control Pre/

differences differences postGroup

p

p p

ASES <

0.001 0.018 0.373 ASES –Pain

<

0.001 <0.001 0.683

SANE <

0.001 0.023 0.076

e284 2019 ASES Specialty Day Meeting Abstracts J Shoulder Elbow Surg2019

Patient satisfaction

Coracoid Transfers Primary OA

Preoperative Final Preoperative Final

Very Dissatisfied 6 (54.5%) 0 (0%) 25 (75.8%) 1 (3%)Dissatisfied 5 (45.5%) 0 (0%) 8 (24.2%) 5 (15%)Satisfied 0 (0%) 2 (20%) 0 (0%) 6 (18%)Very Satisfied 0 (0%) 8 (80%) 0 (0%) 21 (64%)

J Shoulder Elbow Surg 2019 ASES Specialty Day Meeting Abstracts e285Volume 28, Number 8

Paper #8 ONE AND TWO-YEAR CLINICALOUTCOMES FOR A STANDARD ALL-POLYETHYLENE GLENOID COMPONENT WITH AFLUTED CENTRAL PEG: ANALYSIS OF 1270INDIVIDUAL PATIENTS FROM 11 DIFFERENTCENTERS

Frederick A. Matsen III, MDa, Joseph P. Iannotti, MD, PhDb, R.Sean Churchill, MDc, Lieven De Wilde Sr., PhD, MDd, T.Bradley Edwards, MDe, Matthew C. Evans, FRACS, MBBSf, EdwardV. Fehringer, MDg, Gordon I. Groh, MDh, James D. Kelly II, MDi,Christopher M. Kilian, MDj, Giovanni Merolla, MDk, TomR. Norris, MDl, Giuseppe Porcellini, MDm, Edwin E. SpencerJr, MDn, Anne Vidilo, Michael A. Wirth, MDp, Stacy M. Russ, BAq,Moni B. Neradilekr, Jeremy S. Somerson, MDs, a Departmentof Orthopaedics and Sports Medicine, University of WashingtonMedical Center, Seattle, WA, USA; bDepartment of OrthopaedicSurgery, Cleveland Clinic, Cleveland, OH USA; cOrthopaedicSurgery, Aurora Health Center, Milwaukee, WI 53209, USA;d Shoulder & Elbow Surgery, Department of Orthopaedic Surgeryand Traumatology, Ghent University Hospital, Ghent, Belgium;e Fondren Orthopaedic Group, L.L.P., Houston, TX, USA; f UpperLimb Unit, Melbourne Orthopaedic Group, Windsor, Melbourne,Australia; gOrthopaedic Shoulder and Elbow Surgery, ColumbusCommunity Hospital Orthopaedics and Sports Medicine, Columbus,NE, USA; h Asheville Orthopaedic Associates, P.A, Asheville, NC,USA; i California Pacific Orthopaedics, San Francisco, CA USA;jOrthopaedic Associates of Wisconsin, Pewaukee, WI, USA;k Shoulder and Elbow Unit, ‘‘D. Cervesi’’ Hospital, Cattolica, Italy;l California Pacific Orthopaedics, San Francisco, CA, USA;mOrthopaedic and Trauma Unit, University of Modena and ReggioEmilia, Via Universita, MO, Italy; n Knoxville Orthopaedic Clinic,Knoxville, TN USA; o Paris Shoulder Unit, Clinique Bizet, Paris,France; p Department of Orthopaedics, The University of TexasHealth Science Center at San Antonio, San Antonio, TX, USA;qDepartment of Orthopaedics & Sports Medicine, University ofWashington, Seattle, WA, USA; r The Mountain-Whisper-LightStatistics, Seattle, WA, USA; s The University of Texas MedicalBranch, Galveston, TX, USA

Investigation performed at the University of Washington, Seattle,WA.

Background:Many different anatomic glenoid components arecurrently in the marketplace, and new ones are being added eachyear. Broad-based, multicenter data are necessary to establish thetrack record for existing components against which the value of newcomponents can be compared. We hypothesized that the clinical out-comes for patients from eleven different centers using an all-polyeth-ylene glenoid component with a fluted central ingrowth peg woulddemonstrate consistent, substantial and clinically important improve-ment in comfort and function.

Methods: We obtained outcome data on 1270 individual pa-tients from eleven different centers using an all-polyethylene glenoidcomponent with a fluted central peg. Rather than considering theaverage outcomes over a range of followup intervals in the differentstudies, we analyzed individual patient outcomes at two discretetime points: one and two years after surgery. We compared theimprovement for each patient to published values for the minimal clin-ically important difference (MCID) and calculated the percent ofmaximal possible improvement.

Results: The mean6SD preoperative scores improved from SST362, ASES 37615, Constant score 36616, and Penn score 30619to two-year means of SST 1062, ASES 90612, Constant 76613,and Penn 80624. A high percentage of patients exceeded theMCID in outcome scores (SST: 96%, ASES: 98%, Constant: 94%,Penn: 93%) and obtained at least 30% of the maximum possibleimprovement (SST: 95%, ASES: 98%, Constant: 91%, Penn: 87%).Clinical outcomes were not worse for the 41% of shoulders with preop-

erative type B glenoids or for the 30% of shoulders with more than 15degrees of glenoid retroversion.

Conclusion: Surgeons in 11 independent practices were ableto obtain robust clinical outcomes in an international group ofover 1200 individual patients using a basic all-polyethylene gle-noid component to address the range of glenohumeral arthriticconditions encountered in their practices. These data for a stan-dard glenoid component in current widespread use provide abenchmark against which the value of new component designscan be compared.

Level of Evidence: Level IV TherapeuticKey Words: glenoid; ingrowth; all-polyethylene; peg; clinical

outcomes; Minimal Clinically Important Difference; Percentage ofmaximal possible improvement.

Paper #9 JOINT CONTACT CHANGES WITHUNDER-SIZED PROSTHETIC RADIAL HEADS

Daniel R. Bachman, MD, Sangeun Park, MD,Sutee Thaveepunsan, MD, James S. Fitzsimmons, BSc, Kai-nan An, PhD, Shawn W. O’Driscoll, PhD, MD, Department ofOrthopedics, Mayo Clinic, Rochester, MN, USA

Introduction: When implanting a prosthetic radial head, itslong-term articulation with the opposing articular cartilage shouldbe considered. Several studies have explored the effects of prosthesisshape and geometry on radiocapitellar contact profiles. Contact areasand pressures have been found to differ significantly between radialhead prostheses and native radial heads. Significant differences inthe contact mechanics of nonanatomic and anatomic radial headprosthesis designs have been reported; particularly their contactwith the lateral trochlear ridge. These abnormalities might be lessenedby down-sizing the diameter of the prosthetic head, which is recom-mended routinely by some surgeons. Our aim was to evaluate radio-capitellar contact pressures in two different commercially availableradial heads both sized according to their respective manufacturers’recommendations as well as under-sized by 2 mm. We hypothesizedthat radiocapitellar contact pressures would be improved in a nonan-atomic prosthesis, but not with an anatomic prosthesis tested in neutraland extension.

Methods: Eight fresh-frozen cadaveric elbows were aligned inneutral-extension and loaded with 100 N using a custom testingapparatus. Radiocapitellar contact pressures were recorded using aTekScan� thin-film pressure sensor. Prosthetic radial head replace-ment was performed with two prostheses: the Anatomic� RH andthe Evolve� Proline RH prosthesis. Each design was sized accordingto the manufacturer’s recommendations, and then again using 2 mmsmaller radial heads.

Results: Representative patterns of contact are illustrated inFigure 1. Average and peak pressures were significantly higherwith the Evolve� than the Anatomic� prostheses(p < 0.03 and0.02 respectively). Peak pressures (Fig. 2) decreased from 4.2 60.5 MPa to 2.9 6 0.3 MPa for the Anatomic� RHs and from 5.66 0.5 MPa to 3.9 6 0.6 MPa when the Evolve were undersizedby 2mm. The mean pressures for the Anatomic� RHs (1.4 6 0.1MPa) did not change significantly with under-sizing (1.3 6 0.1MPa, p ¼ 0.12); whereas, the mean pressures of the Evolve (1.66 0.1 MPa) significantly reduced with under-sizing (1.4 6 0.1MPa, p < 0.02).

Conclusion: Both mean and peak pressures were initially highfor Evolve� RH sized based on the short axis diameter and wereimprovedwith further under-sizing by 2mm. Peak, but not mean, con-tact pressures were improved by under-sizing the Anatomic� pros-thesis based on the long axis diameter. These findings support theclinical recommendation of some surgeons to undersize the Evolve�prosthesis by 2 mm smaller diameter than the current manufacturer

Figure 1 A set of pressure maps for a representative specimen showing distribution for varying design and size(lighter colors ¼ higher pressures).

Figure 2 Radiocapitellar contact pressures (mean6 standard er-ror). 0 mm represents manufacturer suggested sizing, -2 mm indi-cates under-sizing. Lowercase letters (i.e. a, b, c) indicate theresults of post-hoc testing using least squares mean comparisons.Columns with letters in common are not statistically different fromone another (P# 0.05). The 5MPa threshold is indicated with a hor-izontal red line.

e286 2019 ASES Specialty Day Meeting Abstracts J Shoulder Elbow Surg2019

suggestion and give reason to consider doing the same for theAnatomic� prosthesis.

Paper #10 PREVENTION OF POST-TRAUMATICELBOW STIFFNESS USING BOTULINUM TOXIN

Henrik C. B€acker, MD, Christina Freibott, BA, Eric F. Swart, MD,Charles M. Jobin, MD, Robert J. Strauch, MD, MelvinP. Rosenwasser, MD, Columbia University Medical Center,Department of Orthopedic Surgery, New York, NY, USA

Background: Approximately 30% of all upper extremity frac-tures are elbow fractures. This may lead to elbow stiffness and hetero-topic ossification resulting in limited range of motion which is achallenging problem. A sufficient functional arc of motion is statedfor flexion-extension 130�-30�-0� and for pronation/ supination50�-0�-50�.

Aim: To investigate the efficacy of Botulinum Toxin (Botox) injec-tions to prevent postoperative elbow stiffness after trauma, we per-formed a study in three steps.

Methods: All patients were included who presented to a sin-gle surgeon with distal humerus fracture, Monteggia fracture, orolecranon fracture. The study was developed in three steps: 1)prospective comparative pilot study to demonstrate the safenessof use and dosage of Botox between 1999 and 2003, 2) dou-ble-blinded prospective, randomized study between 2003 and2007 to evaluate the functional outcome scores and range of mo-

tion and finally, 3) a retrospective study between 2007 and 2017to assess clinical impact and the functional outcome after elbowfracture. For the prospective group, the Disabilities of the Arm,Shoulder, and Hand (DASH) score, Visual Analogue Scale forpain as well as the range of motion (ROM) were assessed afterthree months, six months and one year. For the retrospective study,range of motion measurements were recorded and analyzed usinga paired t-test.

Results: In total, 79 patients were included, 32 patients (44%)received Botox injections and 47 patients (54%) were in the controlgroup. The pilot study reported that Botox is a safe and effectivemethod to prevent posttraumatic elbow stiffness, lasting six months,with an optimal dosage of 100 units each for the brachialis muscleand biceps brachii. In the prospective randomized study, a significantdifference (p<0.05) in VAS score and high positive trend in DASHscore after 1 year (p ¼0.06) between the botulinum (VAS1.265.2; DASH 11.18611.0) and control group (VAS5.7621.9; DASH 54.4667.59) could be identified. For ROM,a positive trend especially for extension could be identified in Monteg-gia and significant difference in Intercondylar fracture (p<0.05) 6-weeks postoperatively.

Conclusions: Botulinum toxin is a safe and promising treatmentto prevent post-traumatic elbow stiffness. Our study demonstratesimproved early range-of-motion, and better functional outcome likeVAS and DASH score.

Paper #11 COUNTERFORCE BRACING OFLATERAL EPICONDYLITIS: A PROSPECTIVE,RANDOMISED, DOUBLE BLINDED, PLACEBOCONTROLLED CLINICAL TRIAL

Martin Kroslak, MBBS, MS, Kajan Pirapakaran, MBBS, , Prof-George AC. Murrell, MD, PhD, Orthopaedic Research Institute,University of New South Wales, St George Hospital Campus,Australia

Background: Counterforce bracing is one of the common treat-ment modalities for tennis elbow. The objective of this study was todetermine whether counterforce bracing offers any additional benefitover placebo bracing in the treatment of tennis elbow.

Methods: This prospective, randomised, double-blinded pla-cebo controlled clinical trial investigated the use of counterforcebracing (n¼17) compared with placebo bracing (n¼14) in the man-agement of acute tennis elbow. Outcome measures included patientrated pain and functional outcomes, epicondyle tenderness andstrength at 6 months and long term. Follow up occurred at 2, 6, 12and 26 weeks, as well as long term (mean follow up 3 years). Thestudy duration was 5 years.

J Shoulder Elbow Surg 2019 ASES Specialty Day Meeting Abstracts e287Volume 28, Number 8

Results: The two groups, counterforce and placebo, were similarin age, sex, hand dominance and duration of symptoms. Both bracesimproved patient rated pain frequency and severity (p<0.01), diffi-culty with picking up objects and twisting motions, and overall elbowfunction (p<0.001) at 6 months and 3 years. Both braces alsoimproved the lateral epicondyle tenderness, grip strength (p<0.01)and modified ORI-TETS (Orthopaedic Research Institute – TennisElbow Testing System) force (p<0.05) at 6 months. Significant inter-group differences were detected for frequency of pain at rest at 6and 12 weeks (p<0.05), level of pain at rest at 2 weeks (p<0.001)and for the patient rated overall elbow function at 26 weeks(p¼0.041).

Conclusion: The counterforce brace provides significant reduc-tion in the frequency and severity of pain in the short term (2-12weeks), as well as overall elbow function at 26 weeks, comparedwith the placebo brace.

Patient rated overall elbow function. Data are presented as mean(standard error of mean), ** p<0.01 and *** ¼ p<0.001 comparedwith time 0 usingWilcoxon signed rank tests. +¼ p<0.05 for compar-ison between groups using Mann-Whitney rank sum test. w, weeks

Paper #12 THE DETERMINATION OFINTEROBSERVER AND INTRAOBSERVERRELIABILITY OF A MAGNETIC RESONANCEIMAGING BASED CLASSIFICATION SYSTEM FORULNAR COLLATERAL LIGAMENT INJURY

Prem N. Ramkumar, MD MBAa, SalvatoreJ. Frangiamore, MDb, Sergio M. Navarro, MDc, T.S. Lynch, MDd,Scott G. Kaar, MDe, Sam Akhavan, MDf,Vasilios Moutzouros, MDg, Robert W. Westermann, MDh, LutulD. Farrow, MDa, Mark S. Schickendantz, MDa, a Cleveland ClinicFoundation, Cleveland, Ohio, USA; b Steadman Philippon ResearchInstitute, Vail, Colorado, USA; c Baylor College of Medicine,Houston, Texas, USA; d Columbia University Medical Center, NewYork, New York, USA; e St. Louis University Hospital, St. Louis,Missouri, USA; f Allegheny General Hospital, Pittsburgh,Pennsylvania, USA; g Henry Ford Health System, Detroit, Michigan,USA; h University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA

Background: Despite improvements in the biomechanics andsurgical options for UCL tears, there remains a need for a reliable clas-sification of UCL tears that has the potential to guide clinical decision-making.

Purpose: The purpose of this cross-sectional study was to assessthe intraobserver and interobserver reliability of the newly proposedMRI-based classification to UCL tears. Secondary objectives includedassessing the impact of additional views, discrimination betweendistal and non-distal tears, and correlation of imaging reads with in-traoperative findings of the UCL.

Methods: Nine fellowship-trained specialists from seven institu-tions independently completed four series surveys consisting of 60 to-tal elbow MRIs with UCL tears using a newly proposed six-stageclassification system. The first and third surveys contained a total of60 coronal MRI images, while the second and fourth contained thesame MRI images with both coronal and axial views presented in arandom order to assess intraobserver variability using the weightedkappa value and impact of additional imaging views. Weightedkappa values were also calculated for each of the four surveys to ac-quire interobserver reliability. Reliability analysis was repeated usinga two-group classification analysis for distal and non-distal disease.Observer readings were compared to intraoperative UCL findings.

Results: For the newly proposed six-stage MRI-based classifica-tion, intraobserver and interobserver reliability demonstrated nearperfect and substantial agreement, respectively. These values onlyincreased when sub-stratified into the two-group distal and non-distaldisease classification (p<0.05). The additional axial view did not sta-tistically improve the agreement between and among readers.Observer readings were accurate for tear grade (partial and com-plete), proximal location, and distal location, but not midsubstancetears, when compared to intraoperative findings from 30 elbows.

Conclusion: Our newly proposed six-stage MRI-based classifi-cation utilizing grade and location of the injury was found to have sub-stantial to near perfect agreement between and within fellowship-trained observers. The results of this study provide a foundation forfuture validation studies, in which the classification system may beassociated with clinical decision-making and patient outcomes.

Figure 1 Examples of each UCL tearTop left: 1A, proximal partial Top right: 1B, proximal complete

Middle left: 2A, midsubstance partial Middle right: 2B, midsubstancecomplete Bottom left: 3A, distal partial Top left: 3B, distal complete

Table 1 MRI-based classification scheme for tears of theUCL.

Stage Description

1A Partial tear of the proximal/humeral UCL1B Complete tear of the proximal/humeral UCL2A Partial tear of the midsubstance UCL2B Complete tear of the midsubstance UCL3A Partial tear of the distal/ulnar UCL3B Complete tear of the distal/ulnar UCL

e288 2019 ASES Specialty Day Meeting Abstracts J Shoulder Elbow Surg2019

Paper #13 PREOPERATIVE EVALUATION OFSPINOGLENOID GANGLION CYST WITH MRI,EMG AND ISOKINETIC MUSCLE TEST: DOES SIZEMATTER?

*Indicates paper nominated for the Neer Award

Sung Min Rheea, Tae Yon Rhie, MD, PhDb, Ho Yun Joungc,Chintan Desai, MBBS, MSd, Joo Han Oh, MDa, a Department ofOrthopaedic Surgery, Seoul National University College ofMedicine, Seoul National University Bundang Hospital, Korea;bNalgae Hospital, Seoul, Korea; c Kidung Hospital, Ansan, Korea;d King Edward Memorial Hospital, Mumbai, India

Background: There are few studies correlating the size of gan-glion cyst at the spinoglenoid notch with electrophysiological alter-ations, muscle power or pain severity.

Materials andMethods: Between June 2010 and November2014, 30 patients (24 males and 6 females) who diagnosed with aganglion cyst at the spinoglenoid notch on MRI were evaluated byEMG/NCV test and isokinetic muscle test. Maximum cyst diameterwas measured on MRI and used for comparison. Pain severity wasestimated by visual analogue scale (VAS). And, pooled sensitivityand specificity analysis was conducted, with an assessment of the sum-mary receiver operating characteristic (ROC) curve.

Results: EMG/NCV test were examined in 27 out of 30 patients.Eight out of 27 patients were diagnosed with suprascapular neuropa-thy. The overall mean cyst size was 2.1cm. The cyst size of EMG pos-itive group was 2.7cm, and size of EMG negative group was 1.8cm.When the size of ganglion cysts was increased 1cm, probability of anabnormal EMG/NCV test were increased 4.32 times (odds ratio:4.32, p ¼ 0.023). Area under the ROC curve (AUC) was 0.822,and set point 2.2cm had most sensitivity (87.5%), specificity(73.7%), positive likelihood ratio (3.3). However, there was no signif-icant difference in the peak torque deficit on external rotation (mean:30.2 (> 2.2 cm) vs. 20.7 (< 2.2 cm); p ¼ 0.156) and abduction(mean: 28.6 (> 2.2 cm) vs. 18.4 (< 2.2 cm), respectively; p ¼0.28) according to the size of ganglion cyst. The mean pain VAS ofall 30 patients was 6.22 (range: 3�9), and there was no statistical dif-ference in pain VAS according to the cyst size (mean: 6.06 (> 2.2 cm)vs. 6.50 (< 2.2 cm), respectively; p ¼ 0.841). Twenty eight out of 30patients had a labral lesion associated with spinoglenoid notch cyst onMRI. We performed SLAP repair in 19 cases, biceps tenodesis in 6cases, biceps tenotomy in 3 cases, and cyst decompression only in 2cases.

Discussion: Large spinoglenoid notch cysts may compress thesuprascapular nerve. Tungi el al. reported that average maximumdiameter of cysts associated with muscle denervation was 3.1cm.However, this study diagnosed muscle denervation on MRI, not theEMG/NCV study. The strengths of this study were as follows; 1) Thecurrent study used needle EMG for the diagnosis of suprascapularneuropathy. 2) This is the first study regarding the correlation withcyst size and suprascapular neuropathy. 3) All patients in the presentstudy have taken EMG/NCV test, isokinetic muscle performance testand MRI evaluation. The limitation of study was 1) small number forsubgroup analysis, 2) postoperative external rotation power andEMG follow up were not analyzed.

Conclusion: The current data suggested that cyst size reflect thecompressive suprascapular neuropathy. Therefore, the decompres-sion surgery would be justified in patients with cyst size greater than2.2 cm.

i Tung GA, Entzian D, Stern JB, Green A. MR imaging and MR ar-thrography of paraglenoid labral cysts. AJR. Am. J. Roentgenol.2000;174(6):1707-15. https://doi.org/10.2214/ajr.174.6.1741707.

Paper #14 * DEVELOPMENT AND VALIDATIONOF A RISK CALCULATOR FOR PROLONGEDOPIOID USE AFTER SHOULDER SURGERY

Allen D. Nicholson, MD, Hafiz F. Kassam, MD, Jacqueline Steele, BA,Natalie Passarelli, Theodore A. Blaine, MD,David Kovacevic, MD, Investigation performed at theDepartment of Orthopaedics and Rehabilitation, Yale UniversitySchool of Medicine, New Haven, Connecticut, USA

Introduction: Opioid addiction is an escalating problem in theUnited States, with 33,091 reported deaths due to opioid overdoses in2015. Although opioids are often an integral part of postoperativepain control, they can have significant side effects including physicaldependence, development of tolerance, respiratory depression, anddeath. Orthopaedic surgeons are the third highest prescribers of opi-oids among physicians in the United States. Properly identifying pa-tients who are at greater risk for prolonged postoperative opioid usecan help direct patients care towards ancillary treatments such asbehavioral therapy, pain management and should ultimately reducethe risk of serious harm. We identified patient covariates associatedwith increased opioid use after shoulder surgery and utilized themto construct a clinical risk calculator to preoperatively predict the riskof opioid usage for longer than 6 weeks following shoulder surgery.

Methods: Patients that underwent shoulder surgery fromJanuary 2015 to February 2017 at a tertiary healthcare systemwere identified and opioid prescription data was collected from theConnecticut Prescription Monitoring and Reporting System (CPMRS).Inclusion criteria were age over 18 and exclusion criteria were pa-tients not registered on CPMRS. Quantities of opioids prescribedwere documented. Chart review identified demographic information,active medications, and medical comorbidities. Logistic regressionwas used to calculate odds ratios of patients using opioids longerthan six weeks and multivariate analysis was performed on ten iden-tified risk factors. The coefficients from these ten chosen predictor vari-ables were used to construct a predictive risk calculator. Thenomogram was validated by the bootstrapping method, and a cali-bration plot was used to examine agreement between observed out-comes and predicted probability. Internal recalibration of the dataset using the bootstrapping method was done by resampling the data-set with replacement 1000 times and running the model fitting each ofthe 1000 datasets.

Results: 563 patients met inclusion criteria, whereas 8 patientswere not registered with the CPMRS website and were excluded.Multivariable analysis demonstrated that the greatest factors for pro-longed opioid use were historical opioid use prior to surgery (within 3years prior to surgery), followed by insurance type, procedure type,BMI, smoking status, and psychiatric disorders. Other factors includedgender, hepatobiliary disease and intestinal disorders, cardiopulmo-nary disease, and neurologic disorders. The ten identified risk factorsof opioid use for greater than 6 weeks following shoulder surgerywere then utilized in constructing a predictive risk calculator (Figure1). The risk calculator is utilized by first identifying the proceduretype, and then drawing a line to the ‘‘points’’ scale at the top of thenomogram to determine how many points are assigned to that pro-cedure type. This is then repeated for the 9 remaining risk factors in

Figure 1 Predictive Clinical Risk Calculator of Opioid Use Longer Than 6 Weeks After Shoulder Surgery.

J Shoulder Elbow Surg 2019 ASES Specialty Day Meeting Abstracts e289Volume 28, Number 8

the nomogram. The ‘‘points’’ from each of the 10 risk factors is thenadded, and the total points are converted to an estimate of the prob-ability of patients using opioids longer than six weeks, using the pointto risk conversion scale at the bottom of the nomogram. The predictionaccuracy for this model was good with a calculated concordance in-dex of 0.766 (95% confidence interval 0.736-0.820).

Conclusion: We developed and validated a preoperative clin-ical risk calculator to predict prolonged opioid use following shouldersurgery. This may be a valuable clinical decision-making tool todecrease opioid over prescription, identify patients benefitting from

referral to pain management specialists, and reduce the risk of opioidabuse and addiction. Although several previous studies have attemp-ted to identify risk factors of prolonged opioid use, none to our knowl-edge have utilized these risk factors to develop a preoperativemultivariate predictive risk calculator of postoperative opioid use.Ideally, such a predictive risk calculator would be integrated into theelectronic medical record or available as an application to allow facilecalculation of prolonged opioid usage and appropriate targeting ofresources for patients at risk following shoulder surgery.

Level of Evidence: Retrospective cohort study, Level III