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J Shoulder Elbow Surg (2014) 23, 1171-1180

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http://dx.doi.org

www.elsevier.com/locate/ymse

SHOULDER & ELBOW CLINICAL PAPERS

Electrothermal arthroscopic capsulorrhaphy:old technology, new evidence. A multicenterrandomized clinical trial

Nicholas G. Mohtadi, MD, MSc, FRCSCa,*, Alexandra Kirkley, MD, MSc, FRCSC (Deceased)b,Robert M. Hollinshead, MD, FRCSCa, Robert McCormack, MD, FRCSCc,Peter B. MacDonald, MD, FRCSCd, Denise S. Chan, MSca, Treny M. Sasyniuk, MSca,Gordon H. Fick, PhDe, Elizabeth Oddone Paolucci, PhDf, Joint Orthopaedic Initiative forNational Trials of the Shoulder–Canada

aUniversity of Calgary Sport Medicine Centre, Department of Surgery, Faculties of Kinesiology and Medicine Calgary,AB, CanadabDepartment of Surgery, University of Western Ontario, London, ON, CanadacDepartment of Orthopedic Surgery, University of British Columbia, Faculty of Medicine, Vancouver, BC, CanadadDepartment of Surgery, University of Manitoba, Faculty of Medicine, Winnipeg, MB, CanadaeDepartment of Community Health Sciences, University of Calgary, Faculty of Medicine, Calgary, AB, CanadafDepartments of Surgery and Community Health Sciences, University of Calgary, Faculty of Medicine, Calgary, AB, Canada

Background: Radiofrequency technology for shoulder instability was rapidly adopted despite limited clin-ical evidence and a poor understanding of its indications. Reports of serious adverse events followed, lead-ing to its abandonment. This paper presents findings from a multicenter randomized clinical trial evaluatingthe safety and efficacy of electrothermal arthroscopic capsulorrhaphy (ETAC) compared with open inferiorcapsular shift (ICS) and reviews the role of randomized trials in adopting new technology.Methods: Patients (>14 years) diagnosed with multidirectional instability or multidirectional laxity withanteroinferior instability and failed nonoperative treatment were enrolled. Patients with bone lesions or lab-ral, biceps anchor, or full-thickness rotator cuff tears were excluded intraoperatively. Outcomes includedWestern Ontario Shoulder Instability Index, function and recurrent instability at 2 years postoperatively,and surgical times.Results: Fifty-four subjects (mean age, 23 years; 37 women) were randomized to ETAC (n ¼ 28) or openICS (n ¼ 26). The groups were comparable at baseline, except for external rotation at the side. At 2 yearspostoperatively, there were no statistically or clinically significant differences between groups for the West-ern Ontario Shoulder Instability Index (P ¼ .71), American Shoulder and Elbow Surgeons score (P ¼ .43),Constant score (P ¼ .43), and active range of motion. Recurrent instability was not statistically different

for this study was provided by the Canadian Institutes of

(Grant FRN 64671) and The Arthritis Society. The probes

rmal capsulorrhaphy procedure were donated by Oratec/

.

of Calgary Conjoint Health Research Ethics Board

udy (Ethics ID# 10650).

*Reprint requests: Nicholas G. Mohtadi, MD, University of Calgary

Sport Medicine Centre, 2500 University Dr NW, Calgary, AB T2N 1N4,

Canada.

E-mail address: mohtadi@ucalgary.ca (N.G. Mohtadi).

ee front matter � 2014 Journal of Shoulder and Elbow Surgery Board of Trustees.

/10.1016/j.jse.2014.02.022

1172 N.G. Mohtadi et al.

(ETAC, 2; open, 4; P ¼ .41). ETAC (23 minutes) was significantly shorter than open ICS (59 minutes)(P < .01) surgery. Three subjects (1 ETAC, 2 open) had stiff shoulders.Conclusions: At 2 years postoperatively, quality of life and functional outcomes between groups were notclinically different. ETAC had fewer complications and episodes of recurrence compared with open surgery.This evidence reinforces the need to critically evaluate new technology before widespread clinical use.Level of evidence: Level II, Randomized Controlled Trial, Treatment Study.� 2014 Journal of Shoulder and Elbow Surgery Board of Trustees.

Keywords: Shoulder; multidirectional instability; anteroinferior laxity; open inferior capsular shift; electro-

thermal arthroscopic capsulorrhaphy; capsular redundancy; quality of life

Electrothermal arthroscopic capsulorrhaphy (ETAC) forshoulder instability has been largely abandoned in ortho-pedics.36,56 Initial reports of ETAC in patients with multi-directional instability (MDI) of the shoulder showedpromising short-term results.34,49 This led to a dramaticproliferation in the number of ETAC procedures.56 Publi-cations reporting serious complications with ETAC soonfollowed, including high failure rates, axillary nerve in-juries, stiffness, and capsular attenua-tions.1,3,11,20,21,25,33,41,45,48,53,58,59 Although severalpublications compared ETAC with the reference standardtechnique, an open inferior capsular shift (ICS), none rep-resented level I evidence.8,14,16-18,29,31,34,46

In an attempt to address this lack of level I evidence, amulticenter randomized clinical trial (RCT) was initiated in1999 by a group of Canadian orthopedic surgeons toevaluate the efficacy of this new technology. The primaryresearch question of the study was to determine the dif-ference in disease-specific quality of life as measured bythe Western Ontario Shoulder Instability (WOSI) Index at 2years in patients with shoulder instability due to ligamen-tous or capsular redundancy who received either an openICS or an ETAC treatment.

The intent of this paper is to report level II clinical ev-idence, based on this RCT, and to demonstrate its impor-tance in evaluating new technology before its adoption inorthopedic practice.

Materials and methods

Patients were recruited between 1999 and 2008 from 9 Canadianorthopedic practices.42 All participating surgeons were fellowship-trained members of the Joint Orthopaedic Initiative for NationalTrials of the Shoulder–Canada (JOINTS-Canada) organization.42

Consecutive patients presenting with shoulder instability dueto ligamentous or capsular redundancy (MDI or multidirectionallaxity with anteroinferior instability [MDL-AII]) were screenedfor inclusion. Eligible patients (Table I) were invited to participateand subsequently provided informed consent. Surgeons classifiedthe patient’s instability as either MDI43 or MDL-AII6 on the basisof previously published criteria and consensus definitions outlinedby JOINTS-Canada.28 Patients completed baseline outcomequestionnaires and were scheduled for elective outpatient surgery.

Patients underwent a standardized diagnostic arthroscopy52 toconfirm the absence of additional disease beyond the capsular-ligamentous redundancy (Table I). Eligible patients were ran-domized intraoperatively, by sequentially numbered, opaquesealed envelopes, to either the ETAC or open ICS procedure.Randomization was based on a computer-generated sequence,with varied block sizes for each surgeon and stratification bydiagnosis (MDI vs MDL-AII).

The open ICS procedure was a modification of the proceduredescribed by Neer and Foster, as described by Schenk andBrems.51 The shoulder capsule was completely exposed and therotator interval was closed when present. AT-shaped capsulotomywas performed with the vertical limb laterally and the transverselimb perpendicular to the glenoid, intersecting near its equator.The capsule was dissected off the humeral neck from rotator in-terval anterosuperiorly to the posterior equator or to the posteriorinferior glenohumeral ligament for patients with MDI and MDL-AII, respectively. The bone adjacent to the articular surface on thesurgical neck of the humerus was roughened to create a bleedingbone surface. With the arm held in 0� flexion, 30� abduction, and30� external rotation, the 2 capsular flaps were shifted to create arobust 2-layered repair, reducing the capsular redundancy.51,57 Thesubscapularis was repaired to its normal anatomic position withnonabsorbable sutures.

The ETAC procedure was performed with the Oratec VulcanGenerator electrothermal system (Smith &Nephew, formerly OratecInterventions Inc, Memphis, TN, USA). The unit was automaticallyset to deliver a temperature of 75�C and 40 watts (Personalcommunication; R. Griffin, Smith and Nephew, Menlo Park, CA;Vulcan generator settings; 2002). An anterior working portal wasestablished with a supplemental accessory posterior portal whengreater accesswas required.25The capsulewas shrunk byuse of a gridpattern.35 Shrinkage was performed from rotator interval ante-rosuperiorly to the posterior equator or to the posterior inferior gle-nohumeral ligament for patients with MDI and MDL-AII,respectively.25 Care was taken to avoid applying heat to the inferiorcapsule in the region from5 to 7 o’clock, within 1 cmof the rim of theglenoid, to avoid the axillary nerve at its most vulnerable point.15

All patients were placed in a shoulder immobilizer with thearm adducted and internally rotated and followed a standardizedsupervised rehabilitation protocol (Appendix 1).

Postoperative visits occurred between 7 and 14 days, then at 6 to8 weeks and 3, 6, 12, and 24 months. A trained evaluator blinded totreatment allocation performed a standardized shoulder examinationand administered the patient-based questionnaires. To protectexaminer ‘‘blinding,’’ patientswore a t-shirt to conceal surgical scars.

Table I Study inclusion and exclusion criteria

Inclusion criteria

Clinical� Age 14 years or older� Diagnosis of multidirectional instability (MDI) or multi-directional laxity with anteroinferior instability (MDL-AII). Diagnosis will require 2 or more of the following:1. Symptomatic translation (pain or discomfort) in one or

more directions: anterior, inferior, or posterior2. Ability to elicit unwanted glenohumeral translations

that reliably reproduce symptoms with 1 of thefollowing tests: the anterior and posterior apprehen-sion tests, the anterior and posterior load and shifttests, the fulcrum test, the relocation test, the Fukudatest, and the push-pull or stress test with the patientsupine

3. Presence of a positive sulcus sign of 1 cm or greatergap that reproduces the patient’s clinical symptoms ofinstability and should be both palpable and visible

4. Symptoms of instability: subluxation or dislocation� Informed written consent� Failed nonoperative treatment (minimum 6 months ofsupervised physiotherapy that included strengtheningexercises and prescribed pain control measures)

Intraoperative� Confirmed capsular-ligamentous redundancy asdetermined by diagnostic arthroscopic examination

Exclusion criteria

Clinical� Neurologic disorder (e.g., axillary nerve injury;syringomyelia)

� Cases involving third-party compensation (i.e., workers’compensation or disability insurance)

� Patients with primary posterior instabilityRadiologic� A bone abnormality (Hill-Sachs or bony Bankart) onstandard series of radiographs consisting of a minimum ofan anteroposterior view, lateral in the scapular plane, andaxillary view

Intraoperative� Presence of a Bankart lesion on arthroscopic examinationof the joint

� Presence of an unstable biceps anchor (i.e., superior labralanterior-posterior lesion on arthroscopic examination ofthe joint)

� Presence of a full-thickness rotator cuff tear

ETAC versus open ICS 1173

Outcomes

The WOSI Index is a valid, reliable, and responsive disease-specific quality-of-life outcome measure.32 The responses weretransformed to measure an overall score of 100, in which a higherscore represents a better quality of life.

The American Shoulder and Elbow Surgeons (ASES) score is ashoulder-specific functional assessment tool.47 The patient portionof the score is divided into 2 sections: (1) pain and instability and(2) activities of daily living. It is reported on a scale of 0 to 100,with 100 representing the best possible outcome.47

The Constant score reflects an overall functional assessment ofthe shoulder.10 This instrument is based on a 100-point scoringsystem calculated from a self-assessment portion (pain and ability toperform activities of daily living) and a clinical assessment of rangeof motion (active) and shoulder strength with a spring-loadedmeasuring device.10 The higher the score, the better the outcome.

Clinical examination

The following standardized clinical examination was performedpreoperatively and postoperatively (at each follow-up interval) inthe clinic. Active range of motion measurements were obtainedwith a goniometer. The patients were in a sitting position for allmeasurements. Forward flexion was measured at maximum arm-trunk angle. External rotation was measured with the arm at theside and with the arm at 90� abduction. Return to sport/activity,return to work, complications, and recurrent events were docu-mented. Recurrent instability was defined as a self-report of 2subluxation events or 1 dislocation.2

Operative times

Surgical time for the ETAC procedure was recorded from the timeof randomization to the time of arthroscopic portal closure. Sur-gical time for the open ICS was recorded from the time of theopen incision to the closure of the wound.

Statistical considerations

Sample sizeThe authors used more than 1 strategy to determine the samplesize for this trial as previously published.42 A total of 29 patientsper group were deemed necessary.42

AnalysesDescriptive statistics were performed to compare baseline char-acteristics. Separate comparisons were made between the 2treatment groups (ETAC and open ICS) and for the type ofinstability (MDI and MDL-AII). Mean WOSI Index, ASES, andConstant scores for the 2 surgical treatment groups were comparedby an independent 2-sample t test at each follow-up interval. Ageneral linear model mixed design analysis of variance of repeatedmeasures and between-subject variable analyses were also per-formed for each outcome. Bonferroni adjustments for multiplecomparisons were made for pairwise contrasts. c2 analysis wasused to compare the recurrence rates between the 2 treatmentgroups. A 5% significance level was used in the analyses. Allpatients were analyzed on an ‘‘intention-to-treat’’ basis.

Study-stopping guidelines were based on recommendationsfrom the Data Safety Monitoring Committee. The Data SafetyMonitoring Committee consisted of 4 individuals with consider-able research experience and backgrounds in epidemiology, clin-ical trial methodology, and orthopedic surgery who wereindependent from the trial.42

Results

The trial was stopped before the required sample size of 58patients (29 per group) was achieved because of slow

Figure 1 Consolidated Standards of Reporting Trials (CONSORT) diagram showing the flow of participants in the trial. MDI, multi-directional instability; MDL-AII, multidirectional laxity with anteroinferior instability; SLAP, superior labral anterior-posterior; ALPSA,anterior labral periosteal sleeve avulsion; ETAC, electrothermal arthroscopic capsulorrhaphy; ICS, inferior capsular shift.

1174 N.G. Mohtadi et al.

recruitment, a high intraoperative exclusion rate (45.5%), andpatients withdrawing (n¼ 3) or declining consent (n¼ 7). Of153 patients screened for eligibility, 99 (64.7%) met the clin-ical inclusion criteria, consented to the study, and underwentsurgery (Fig. 1). Of those having surgery, 54 (54.5%) met theintraoperative inclusion criteria and were randomly assignedto the ETAC (n ¼ 28) or open ICS (n ¼ 26) procedure.

At 2 years of follow-up, 3 patients in the ETAC groupand 4 in the open ICS group were lost to follow-up for anoverall loss to follow-up rate of 13% (Fig. 1).

Baseline characteristics are presented in Table II andTable III.

Outcomes

There were no statistically or clinically significant dif-ferences in mean WOSI Index, ASES, or Constant scores

between groups at any postoperative interval (Table IV).For the WOSI Index, ASES, and Constant outcomes,both groups improved statistically significantly frombaseline to 2 years postoperatively (P < .01). Changes inoutcome scores between groups were not statisticallysignificant.

Clinical examination

There were no statistically or clinically significant differ-ences between groups at any postoperative interval forrange of motion (Table V). Two patients (7.1%) in theETAC group and 3 patients (15.4%) in the open ICS groupexperienced an episode of recurrent instability. This dif-ference was not statistically significant (P ¼ .34). All epi-sodes were atraumatic. Characteristics of these patients areoutlined in Table VI.

Table II Baseline characteristics of the patients randomized in the trial to ETAC or open ICS

Characteristic ETAC (n ¼ 28) Open ICS (n ¼ 26)

Mean age, years (SD; range) 22.4 (5.5; 15.3-35.1) 24.3 (8.0; 16.1-44.8)Gender (male/female) 6/22 10/16Involved dominant shoulder 11 12WOSI Index mean score (SD) 42.0 (24.2) 41.5 (21.9)ASES mean score (SD) 49.2 (20.8) 52.8 (18.3)Constant mean score (SD) 66.7 (12.2) 67.9 (9.8)Forward elevation (SD), degrees 165 (23) 170 (16)Abduction (SD), degrees 163 (26) 166 (20)External rotation at the side (SD), degrees 66 (13)) 75 (18))

External rotation in abduction (SD), degrees 91 (16) 94 (20)Internal rotation in abduction (SD), degrees 72 (19) 68 (18)

ETAC, electrothermal arthroscopic capsulorrhaphy; ICS, inferior capsular shift; SD, standard deviation; WOSI, Western Ontario Shoulder Instability; ASES,

American Shoulder and Elbow Surgeons.) Statistically significant, P < .05.

Table III Comparison of baseline characteristics for patients with MDI and MDL-AII

Characteristic MDI (n ¼ 26) MDL-AII (n ¼ 28)

Mean age, years (SD; 95% CI) 22.7 (5.2; 20.5-24.8) 23.9 (8.2; 20.7-27.1)Gender (male/female) 8/18 8/20Involved dominant shoulder 11 12WOSI Index mean score (SD) 47.0 (22.5) 36.9 (22.5)Forward elevation (SD), degrees) 174 (11) 162 (24)Abduction (SD), degrees 167 (21) 161 (26)External rotation at the side (SD), degrees 73 (18) 69 (14)External rotation in abduction (SD), degrees 89 (20) 96 (16)Internal rotation in abduction (SD), degrees 73 (19) 66 (17)

MDI, multidirectional instability; MDL-AII, multidirectional laxity with anteroinferior instability; SD, standard deviation; CI, confidence interval; WOSI,

Western Ontario Shoulder Instability.) Statistically significant, P ¼ .018.

ETAC versus open ICS 1175

Operative times

There was a statistically significant difference in meansurgical time between groups (from beginning of the allo-cated procedure to wound closure): ETAC, 23 minutes(standard deviation, 15 minutes), vs open ICS, 59 minutes(standard deviation, 26 minutes) (P ¼ .01).

Complications and adverse events

Three patients (1 ETAC, 2 open ICS) developed adhe-sive capsulitis/stiff shoulders postoperatively despiteaggressive physiotherapy. They required manipulationunder anesthesia or arthroscopic arthrolysis, with com-plete resolution. One patient in the open ICS groupreported symptoms of a stiff shoulder but withdrewfrom the trial before the diagnosis could be confirmed.No other major complications were observed throughoutthe trial.

Discussion

This studywas designed to obtain level II evidence on the safetyand efficacy of ETAC in a well-defined population comparedwith the existing ‘‘gold standard,’’ open ICS. The study wasinitiated when the application radiofrequency technology wasmarketed as an easy and innovative technique for shoulderinstability. ETAC procedures were being performed on awidespread basis, with limited clinical evidence of efficacyand effectiveness. Subsequently, publications reportingserious adverse events with ETAC procedures emerged andnegatively affected patient recruitment for thistrial.1,3,11,20,21,25,33,41,45,48,53,58,59 Patients canceled surgery,withdrew consent, or declined participation often because ofinformation found on the internet.42 In 2008, the study’s DataSafety Monitoring Committee recommended closing trialrecruitment. The recommendations were attributed not toserious complications related to thermal capsulorrhaphybut to adiminishing relevance of the trial to the orthopedic community.

Table IV Mean WOSI Index, ASES, and Constant scores for the ETAC and open ICS groups at each follow-up period

Group Baseline 3 Months 6 Months 1 Year 2 Years

WOSI Index scoresETACMean (SD) 42.0 (24.2) 56.7 (25.1) 63.0 (28.3) 68.6 (27.1) 73.8 (23.9)95% CI 32.2-51.7 46.3-67.1 51.8-74.2 57.1-80.0 63.9-83.7Change from baseline 0 14.7 21.0 26.6 31.8

Open ICSMean (SD) 41.5 (21.9) 51.8 (22.3) 59.5 (25.8) 79.7 (18.8) 77.2 (19.7)95% CI 32.7-50.4 42.2-61.4 48.6-70.4 71.8-87.6 68.2-86.1Change from baseline 0 10.3 18.0 38.2 35.7

ASES scoresETACMean (SD) 49.2 (20.8) 68.3 (21.3) 78.6 (17.2) 82.2 (17.4) 81.2 (20.5)95% CI 40.4-58.0 59.5-77.1 71.8-85.4 74.9-89.5 72.8-89.7Change from baseline 0 19.1 29.4 33.0 32.0

Open ICSMean (SD) 52.8 (18.3) 62.5 (25.3) 76.0 (22.2) 82.5 (18.9) 86.8 (17.7)95% CI 45.2-60.3 51.8-73.2 66.8-85.2 74.5-90.5 78.7-94.8Change from baseline 0 9.7 23.3 29.7 34.0

Constant scoresETACMean (SD) 66.7 (12.2) 70.2 (15.0) 79.9 (11.5) 80.2 (13.5) 82.6 (6.7)95% CI 61.8-71.7 63.0-77.4 75.1-84.6 74.3-86.0 79.7-85.5Change from baseline 0 3.5 13.2 13.5 15.9

Open ICSMean (SD) 67.9 (9.8) 67.8 (19.5) 76.3 (17.5) 86.5 (8.7) 85.2 (11.1)95% CI 63.4-72.3 58.0-77.5 67.8-84.7 82.4-90.5 80.0-90.4Change from baseline 0 0.1 8.4 18.6 17.3

WOSI, Western Ontario Shoulder Instability; ASES, American Shoulder and Elbow Surgeons; ETAC, electrothermal arthroscopic capsulorrhaphy; ICS, inferior

capsular shift; SD, standard deviation; CI, confidence interval.

1176 N.G. Mohtadi et al.

The full sample size was not obtained. However, posthoc power analysis shows that with a sample size of 21 pergroup, an a of .05, and a difference of 20% on the primaryoutcome, the calculated power was 75%.

Nevertheless, this trial offers valuable information. Thetrial has enabled better characterization and evaluation of adistinct population of patients with isolated primary liga-mentous laxity or capsular redundancy in the shoulder (i.e.,MDI/MDL-AII, no labral or bone disease). This studyinitially stratified patients according to the type of insta-bility (MDI or MDL-AII). The type of instability wasconsidered an important prognostic factor in determiningoutcome of treatment. However, the baseline characteristics(Table III) suggest that these patients are similar. There wasno difference in 2-year WOSI Index scores within eachtreatment group, irrespective of the type of instability. Thiswould suggest that classification as MDI or MDL-AII is notan important prognostic factor, as was originally hypothe-sized. The classification of shoulder instability and there-fore assessing the outcome of surgical treatment aredifficult when surgeons compare mixed groups of pa-tients.22-25 The Norwegian Shoulder Registry recentlypublished WOSI Index data of patients with various forms

of shoulder instability. The baseline and 1-year post-operative scores for patients with arthroscopically repairedMDI are consistent with the WOSI Index scores seen in ourtrial.7 The treatment groups were comparable in everyrespect, with the exception of baseline external rotation atthe side and forward elevation in comparing instabilitysubgroup types, MDI and MDL-AII. These statisticallysignificant differences in active range of motion can beexplained on the basis that randomization cannot be aguarantee that the study groups will be identical. It can alsobe due to the relatively small sample size, multiple com-parisons, or spurious findings. Nevertheless, both treatmentarms demonstrated significant improvements in all out-comes from baseline to 2 years.

Failure rates in MDI patients having thermal capsulor-rhaphy have been reported between 24% and59%.3,24,34,40,53 The definition of ‘‘failed’’ treatment for apatient with MDI or MDL-AII is difficult because both painand instability episodes are paramount in the clinical pic-ture. Failure in this trial was defined as patient-reportedepisodes of recurrence and occurred in 2 patients (7.1%)who underwent the ETAC procedure and in 3 patients(11.5%) having an open ICS.

Table V Mean range of motion measurements comparing the involved and uninvolved shoulders of patients in each group at baselineand 2-year follow-up

ROM Measurement Time period ETAC Open ICS

Involved Uninvolved Involved Uninvolved

Forward elevation (SD), degrees Baseline 165 (23) 177 (7) 170 (16) 174 (9)2 years 172 (10) 173 (9) 173 (8) 173 (10)

Abduction (SD), degrees Baseline 163 (26) 173 (13) 166 (20) 171 (14)2 years 172 (15) 172 (18) 176 (10) 177 (6)

External rotation at side (SD),degrees

Baseline 66 (14)) 72 (16) 75 (18)) 75 (16)2 years 64 (17) 71 (15) 67 (13) 70 (17)

External rotation in abduction(SD), degrees

Baseline 91 (16) 94 (16) 94 (20) 96 (18)2 years 93 (16) 97 (12) 94 (14) 102 (19)

Internal rotation in abduction(SD), degrees

Baseline 72 (19) 75 (18) 68 (18) 72 (15)2 years 73 (20) 74 (20) 64 (20) 75 (20)

ETAC, electrothermal arthroscopic capsulorrhaphy; ICS, inferior capsular shift; SD, standard deviation.) Statistically significant, P < .05.

Table VI Characteristics of patients experiencing episodes of recurrent instability

Gender Age(years)

Diagnosis Traumatic vsatraumatic

Time offailure(months)

Recurrentinstability

WOSI atbaseline

WOSI at2 years

PrefailureWOSIscore

Treatment

OpenF 17.3 MDI Atraumatic 19 Subluxation 6.10 45.43 45.71 Revision open posterior

stabilizationM 16.8 MDL-AII Atraumatic 48 Subluxation 43.24 93.32 93.32 Physiotherapy treatment with

strengthening; resolvedM 18.9 MDL-AII Atraumatic 15 Subluxation 29.14 53.29 38.96 Physiotherapy treatment with

strengthening; ongoingETAC

F 17.4 MDL-AII Atraumatic 10 Subluxation 4.38 4.19 16.00 2 revisions: open ICS;arthroscopic plication

F 19.4 MDL-AII Atraumatic 27 Subluxation 26.75 78.87 76.65 Revision open stabilizationwith ICS

WOSI, Western Ontario Shoulder Instability Index; MDI, multidirectional instability; MDL-AII, multidirectional laxity with anteroinferior instability; ETAC,

electrothermal arthroscopic capsulorrhaphy; ICS, inferior capsular shift.

ETAC versus open ICS 1177

Structural integrity of the labrum and direction ofinstability have been identified as risk factors contributingto the failure of thermal capsulorrhaphy. A retrospectivecase series of 80 shoulders having ETAC reported failureswith (22%) and without (39%) concomitant labral repair.54

Another series of 85 patients receiving ETAC for differentshoulder instability conditions at 4 years reported failuresin anterior instability with and without a Bankartlesion (26% and 33%, respectively), posterior insta-bility (60%), anteroposterior instability (57%), andMDI (59%).24 Of the 5 patients in our study who experi-enced recurrent instability, 4 were diagnosed with MDL-AII (open, 2; ETAC, 2), but all patients with failure wereconsiderably younger (average, 18 years) compared withthe overall group means.

Clinically important postoperative stiffness was a prob-lem in 3 patients (1 ETAC and 2 ICS). It is possible that

additional scarring was introduced by the diagnosticarthroscopy, which was part of the open ICS procedure. Thiswas not statistically different between groups.

Severe complications with ETAC were the impetus forabandonment of this technique, including capsularthinning,12,39,45,59 axillary nerve damage,13,21,33,38,41,59

chondrolysis,4,9,11,19,20,44 and capsular necrosis and stiff-ness.5,39-41,45 Three cases of adhesive capsulitis/stiffness wereobserved in this trial but resolved completely. The complica-tions of axillary nerve injury, capsular disruption, and thermalchondrolysis are grave and lifelong consequences for a youngpatient presenting with shoulder instability.20,21,45 No seriouscomplications were seen in this trial. This could be attributedto the relatively small number of patients. However, theoperative protocols and explicit techniques were standardizedacross all centers.42 The surgeons were experienced in bothopen and arthroscopic treatment of shoulder instability,

1178 N.G. Mohtadi et al.

temperature settingswere preset, a grid patternwas used, and aspecific ‘‘shrink’’ region was outlined.25,35,42 If inadequatetissue shrinkage was noted with first pass of the heat probe,only one additional attempt was permitted.

The current operative gold standard for patients withshoulder instability due to primary ligamentous laxity re-mains inconclusive. A systematic review (level IV) in 2012demonstrated no differences with respect to recurrentinstability, return to sport, loss of external rotation, orcomplications between arthroscopic capsular plication andopen ICS in MDI patients.26 Another review in 2010 sug-gested that open ICS is the gold standard operative treat-ment of patients with shoulder instability due to jointhyperlaxity.27 Thermal capsulorrhaphy has been successfulin reducing capsular volume (between 26% and 35%) whenit is used in isolation30 or as an adjunct to arthroscopicplication (mean reduction of 41%).30,37,55 However, sutureplication is considered by some surgeons to be more pre-dictable and safer than thermal shrinkage.54 The results ofthis trial suggest that ETAC yields outcomes and compli-cation rates similar to those of an open ICS in this patientpopulation. These findings are in stark contrast to previ-ously reported case series and cohort studies of ETAC andprovoke the question, Is there a role for thermal technologyin shoulder instability?

Limitations

The study was stopped before the sample size was ach-ieved. The strict inclusion criteria identified a highly spe-cific and uncommon population of patients with shoulderinstability without any labral or bone disease. Applicationof strict exclusion criteria resulted in a 45% intraoperativeexclusion rate. Investigators also overestimated the numberof patients with pure MDI and MDL-AII.42 Compoundingthis recruitment problem was the negative selection biasresulting from the damaging reports on thermal technology.The lessons learned from this multicenter RCT have beenpreviously published.42 The lack of long-term follow-upbeyond 2 years is a recognized limitation of this study.However, in a similar group of patients, failures were re-ported early within a 2-year period from the indexprocedure.46

Strengths

This multicenter study was rigorously designed andexecuted; it included a well-defined patient population,intraoperative randomization, detailed perioperative pro-tocols, and blinded data collection procedures. The trial’sData Safety Monitoring Committee carefully monitored allserious adverse events to ensure patient safety and providedimpartial, pertinent advice. Arduous patient tracking by theresearch team resulted in a relatively low loss to follow-uprate.

Role of RCTs in the evolution of new orthopedictechnology

Virk and Kocher56 reviewed the events that occurred withthe introduction, adoption, and abandonment of ETAC.They emphasized the need for RCTs and advocatedchanges in the regulatory approval process for orthopedictechnology to include mandating postmarket surveillance,clinical data, and more specific clinical indications of use.56

The results of this trial may be helpful in the re-evaluationof ETAC as a treatment option for shoulder instability.However, the authors’ intent was to further emphasize theimportance and relevance of conducting RCTs before theadoption of new surgical technology. The question ofwhether it is the responsibility of the manufacturer ormedical community to conduct these trials is up for debate.It is imperative that trials of this nature be designed tocomplete patient recruitment in a time-sensitive mannerand incorporate stopping rules to protect the researchers,patients, and stakeholders from continuing a study that maybe clinically or commercially irrelevant when complete.50

Conclusion

In patients presenting with failed nonsurgical treatmentfor shoulder instability due to ligamentous laxity, ETAC isa viable treatment option to an open ICS with respect todisease-specific quality of life, overall shoulder function,recurrent instability, and complication rates. This trialdemonstrates the importance of completing studies withlevel II evidence in a time-sensitive manner. It also em-phasizes the role and significance of RCTs in evaluatinginnovative technology beforewidespread marketing. Thistrial demonstrates the value and utility of a clearly definedpatient population, strict adherence to surgical technique,use of validated patient-reported outcomes, and method-ology to determine efficacy of a new procedure.

Acknowledgment

The following surgeon members of the Joint OrthopaedicInitiative for National Trials of the Shoulder (JOIN-TS)–Canada have screened subjects for this trial: Dr.Nicholas Mohtadi and Dr. Robert Hollinshead (Calgary,AB), Dr. Laurie Hiemstra (Calgary/Banff, AB), Dr.Robert McCormack (New Westminster, BC), Dr. RobertBalyk (Edmonton, AB), Dr. PeterMacDonald (Winnipeg,MB), Dr. Warren Froese (Winnipeg, MB), Dr. AlexandraKirkley (London, ON, deceased), Dr. Scott Mandel(Hamilton, ON), Dr. Darren Drosdowech (London, ON),and Dr. Robert Litchfield (London, ON).

Heather Hannaford and Jocelyn Fredine assisted withthe data collection and entry.

ETAC versus open ICS 1179

Randomization codes were generated by Dr. GordonFick. Data management was supervised by Dr. Fick, anddata analyses were performed by Dr. Elizabeth OddonePaolucci.

Disclaimer

The authors, their immediate families, and any researchfoundation with which they are affiliated did not receiveany financial payments or other benefits from anycommercial entity related to the subject of this article.

Supplementary data

Supplementary data related to this article can be found athttp://dx.doi.org/10.1016/j.jse.2014.02.022

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