Rockwood type III acromioclavicular dislocation: Surgicalversus conservative treatment

C. Gstettner, MD,a M. Tauber, MD,a W. Hitzl, PhD,b and H. Resch, MD,a Salzburg, Austria

The best treatment for Rockwood type III injuries is stillcontroversial. During a retrospective study, 24 patientswho were treated surgically with a hook plate and 17conservatively treated patients were examined witha mean follow-up of 34 months. The Oxford ShoulderScore, Simple Shoulder Test, and Constant score wereassessed at the follow-up examination. Stressradiographs of both shoulders were taken, and thecoracoclavicular distance, as well as the width of theacromioclavicular joint, was measured. The meanConstant score was 80.7 in the conservatively treatedgroup and 90.4 in the group that underwent surgery. Themean coracoclavicular distance was 15.9 mm in theconservatively treated group and 12.1 mm in thesurgically treated group. These differences weresignificant (P < .05, Mann-Whitney U test and Studentt test). In this study, better results were achieved by surgicaltreatment with the hook plate than by conservativetreatment. (J Shoulder Elbow Surg 2008;17:220-225.)

The best primary treatment for acute acromioclavicu-lar dislocation is still controversial.4,13 Today, inGermany and Austria, Rockwood type I and II injuriesare commonly treated nonoperatively whereas type IIIand VI injuries are usually treated surgically.2 In previ-ous studies on this subject, the Rockwood classificationof acromioclavicular (AC) joint injuries was often notused when including patients in a study group orexcluding them from a study group.13 The result isthat within 1 study group, several types of AC jointinjuries were often present.1,9,12,15,17 The differenttypes of AC dislocation according to Rockwood,13

however, vary considerably as far as the degree ofdamage to surrounding soft tissue and muscles isconcerned. Therefore, it is necessary to investigate

From the Department for Traumatology and Sports Injuriesa andResearch Office,b Paracelsus Medical University.

Reprint requests: Clemens Gstettner, MD, Department for Traumatol-ogy and Sports Injuries, Paracelsus Medical University, MullnerHauptstrasse 48, A-5020 Salzburg, Austria (E-mail:Clemens_Gstettner@gmx.at).

Copyright ª 2008 by Journal of Shoulder and Elbow SurgeryBoard of Trustees.

1058-2746/2008/$34.00doi:10.1016/j.jse.2007.07.017

220

each type of Rockwood injury separately from theothers. In this study, only Rockwood type III injurieswere dealt with.

MATERIALS AND METHODS

Two differently treated groups of patients in whom a Rock-wood type III injury to the AC joint had occurred were inves-tigated during a retrospective study. Their clinical andradiologic results were compared.

Between January 1, 2000, and January 1, 2005, 87patients with acute AC dislocation (Rockwood type III-V)13

were treated in our department. The diagnosis wasestablished clinically and radiologically (anteroposterior[AP], axillary, and stress views of the involved shoulder).Of the 87 patients, 30 were treated conservatively and 57were treated surgically. Rockwood type IV and V injurieswere always treated surgically. There were no type VIinjuries during the time of the study. The treatment ofRockwood type III injuries was not uniform.

Once the diagnosis of Rockwood type III AC dislocationwas established, the patients were presented with thepossible treatment options. They were told that conservativetreatment would consist of immobilization by a shouldersling and functional therapy. They were also told that thecurrent deformity of the shoulder profile would persist; that,by this kind of treatment, no reduction of the AC joint wouldbe achieved; and that carrying burdens (such as a rucksack)could be troublesome in the future.

They were also told about the operative treatment with thehook plate, especially about the scar, which would beunavoidable from surgery, and the necessity of a secondoperation to remove the implant after 12 weeks. Finally,the patients were told that there were no evidence-basedmedical guidelines for the treatment of Rockwood type IIIinjuries on the whole but that, in the international literature,surgery was recommended in young, active patients withhigh demands on shoulder function. The choice of treatmentwas finally left to the patient.

The inclusion criteria were an acute Rockwood type III ACdislocation with complete rupture of the AC and coracocla-vicular ligaments, persistent gross displacement of the distalclavicle superiorly relative to the acromion by a shaft widthin comparison to the other side, and a consistent 25% to100% increase in the coracoclavicular interspace relativeto the unaffected side. The last 2 criteria were evaluatedon an AP radiograph centered on the AC joint. Only patientsaged between 16 and 70 years who had not had any kindof injury or surgery to the injured shoulder before wereincluded, with a follow-up of at least 12 months. Onlypatients with either surgical treatment with a hook plate or

J Shoulder Elbow Surg Gstettner et al 221Volume 17, Number 2

conservative treatment were included (3 patients had beentreated with a Bosworth screw and 4 with transarticularKirschner wires and tension-band wiring).

The exclusion criteria were an acute type Rockwood typeI, II, IV, or V AC dislocation; a chronic AC dislocation; con-comitant injuries to the respective shoulder; and surgicaltechniques other than a hook plate.

Of the patients, 28 in the surgical group (3 female and 25male) and 22 in the conservatively treated group (2 femaleand 20 male) met the selection criteria and were included inthe study. The mean age in the conservatively treated studygroup was 36.2 6 12.6 years (range, 21-69 years); themean age in the surgically treated study group was 37.26 10.6 years (range, 16-60 years). The 2 study groupswere statistically comparable with regard to sex and age.

The follow-up evaluation consisted of a clinical and radio-logic examination. For all patients, the clinical examinationwas conducted and the radiographs reviewed by the same 2independent investigators, neither of whom had partici-pated in the treatment decision or the primary treatment ofthe patients. During the clinical examination, the Constantscore was assessed for the injured shoulder and oppositeshoulder.5 The difference between both shoulders was calcu-lated. These numbers were used to compare the 2 treatmentgroups. The Simple Shoulder Test (SST) and the OxfordShoulder Score (OSS) were used as subjective tests.8,10

Both questionnaires assess the patient’s personal satisfactionwith the result of the treatment by asking simple questionsthat deal with everyday life. Furthermore, the patients wereasked to evaluate the shoulder function of the injuredshoulder compared with the other shoulder on a visualanalog scale.

The radiologic examination consisted of AP and axillaryradiographs for each shoulder, as well as bilateral stressradiographs.4,18 The coracoclavicular distance and thewidth of the AC joint were measured with and without stresson both sides (Figure 1). The AC joint index (ie, the quotientbetween the width of the injured and opposite AC joint) wascalculated.11 AC arthrosis and calcification of the coraco-clavicular ligaments were recorded.

Conservative treatment of skillful neglect consisted ofimmobilization of the respective arm in a sling until the acutepain subsided and analgesics and physical therapy untila free range of movement was achieved.3,16

Operative technique

To stabilize the AC joint, a hook plate was used in allcases (AC-Platte, modifiziert nach Dreithaler; aap Implan-tate AG, Berlin).6,7 The operative approach was an anteriorsaber-cut incision of approximately 5 cm in length. Theperiosteum was carefully detached from the lateral clavicle,and the joint capsule was released. The intra-articular diskwas not removed but was repositioned in all cases. Insome cases, when the disk showed tears on close inspection,they were sutured. After splitting of the deltoid muscle, thetorn coracoclavicular ligaments were exposed and resorb-able sutures were placed in them. The hook of the platewas inserted under the acromion and dorsal to the AC joint,and the joint was reduced by means of the plate. Afterfixation of the plate, the sutures in the torn coracoclavicularligaments were tied. The periosteum and the muscles were

then cautiously sutured together above the plate. Postopera-tively, the arm was immobilized in a sling for 4 weeks.During this time, the patient engaged in physical therapy,including passive motion twice a week. After 4 weeks, thepatient was allowed to elevate and abduct the arm activelyto a level of 90�. The plate was removed after 12 weeks.

Statistical methods

All computations were done with STATISTICA software,version 6.0.14 The clinical results were compared by useof the Mann-Whitney U test. The radiologic results werecompared by use of the Student t test (2-sided). P < .05was considered statistically significant.

RESULTS

It was possible to examine 41 of the 50 patientsincluded in the study at the follow-up examination,for a follow-up rate of 82%. The other 9 patients couldnot be contacted or were not interested in a follow-upexamination. Of these 41 patients, 17 had beentreated conservatively and 24 surgically. The meanfollow-up time was 36.8 months (range, 14-70months) for the conservatively treated group and32.1 months (range, 14-56 months) for the surgicalgroup. The right shoulder was affected in 26 casesand the left in 15. The dominant shoulder was affectedin 9 conservatively treated patients (53%) and14 surgically treated patients (58%).

Among the 28 patients who underwent surgery,there was 1 hematoma (needing revision) and 2 subcu-taneous infections (1 needing revision). In one59-year-old patient, the plate had to be removed after55 days, because the hook cut upward through theacromion (Figure 2). This patient still achieveda Constant score of 96 for the injured shoulder onclinical examination.

In the conservatively treated group, the meanConstant score was 80.7 6 17.4 for the injuredshoulder and 94.6 6 6.6 for the opposite side. In

Figure 1 Coracoclavicular distance (A) and AC joint width (B).

222 Gstettner et al J Shoulder Elbow SurgMarch/April 2008

Figure 2 Radiographs of a 59-year-old patient 11 days (A) and 32 days (B) after surgery. The hook of the plate cutupward through the acromion.

the surgically treated group, the mean Constant scorewas 90.4 6 12.9 for the injured shoulder and96.8 6 4.7 for the opposite side.

There was no significant difference in the Constantscore for the uninjured shoulder between the 2 groups(P > .05). As far as the injured shoulder wasconcerned, the results of the surgically treated groupwere significantly better than those of the conserva-tively treated group (P < .05). The mean scoredifference between injured and uninjured shoulderswas also significantly less in the surgically treatedgroup (P<.05). As far as the individual subcategoriesof the Constant score were concerned, the meanscores achieved for pain and power were significantlyhigher (P < .05) in the group that had surgery than inthe conservatively treated group whereas there wasno significant difference between the 2 groups in theother subcategories (P > .05) (Tables I and II).

The mean SSTscore was 9.9 6 2.6 in the conserva-tively treated group and 11.3 6 1.3 in the surgicallytreated group. There was no significant difference(P > .05) (Table III).

The mean OSS was 18.7 6 6.3 in the conserva-tively treated group and 16.0 6 4.8 in the surgicallytreated group. This difference was not statisticallysignificant (P > .05) (Table III).

In the conservatively treated group, patients esti-mated that their shoulder function (visual analogscale) on the injured side was, on average, 77.6%6 24.4% of that compared with the uninjured shoul-der. The patients who had received surgical treatmentestimated their shoulder function on the injured side,as compared with the uninjured side, to be89.2% 6 17.9%, on average. The differencebetween the 2 groups was not significant (P > .05)(Table III).

In the conservatively treated group, 7 patients ratedtheir result as excellent, 3 as good, 3 as fair (accept-

able), and 4 as poor. Thus, 10 of 17 conservativelytreated patients (58.8%) achieved excellent or goodresults. In the surgically treated group, 16 patientsrated their results as excellent, 5 as good, 1 as fair(acceptable), and 2 as poor. Therefore, 21 of 24surgically treated patients (87.5%) achieved excellentor good results.

When asked which form of treatment they wouldchoose in case of a new AC dislocation, 5 patientsin the conservatively treated group stated that theywould now undergo surgery whereas 10 said thatthey would again choose conservative treatment.Two patients did not answer the question. In the surgi-cally treated group, 20 of 24 patients said that theywould again choose surgery whereas 3 would havechosen conservative treatment. One patient did notanswer the question.

In the conservatively treated group, 15 of 17patients had been participating in sports at leastonce a week before the injury. At the follow-up exam-ination, 11 (64.7%) had returned to their previouslevel of activity. In this group, 4 (23.5%) reportedthat a reduction in their sporting activities had beennecessary because of their AC joint injury. In the

Table I Clinical results: Constant score

Surgically treatedgroup (n ¼ 24)

Conservatively treatedgroup (n ¼ 17)

Mean SD Mean SD

Injured shoulder 90.4 12.9 80.7 17.4Opposite side 96.8 4.7 94.6 6.6Difference 6.4 11.5 13.9 14.2Pain 12.6 3.9 10.2 4.9Range of movement 38.3 3.1 36.8 4.8Power 21.4 4.7 17.1 6.2

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Table II Statistical comparison of clinical results (Constant score) by Mann-Whitney U test

Surgically treated group (n ¼ 24) Conservatively treated group (n ¼ 17)

Median 25th Percentile 75th Percentile Median 25th Percentile 75th Percentile P value

Injured shoulder 96 86 99.5 86 68 94 .029*Opposite side 98 95.5 100 98 91 100 .404Difference 1 0 5 8 4 23 .009*Pain 14.5 12 15 12 7 14 .031*Range of movement 40 38 40 39 36 40 .315Power 24 19 25 14 13 25 .040*

*Statistically significant.

Table III Statistical comparison of subjective results by Mann-Whitney U test

Surgically treatedgroup (n ¼ 24)

Conservatively treatedgroup (n ¼ 17)

Median 25th Percentile 75th Percentile Median 25th Percentile 75th Percentile P value

SST 12 11 12 11 8 12 .059OSS 14.5 12 19.5 16 14 22 .077Visual analog scale (%) 100 85 100 90 60 100 .068

surgically treated group, 19 of 24 patients had beenparticipating in sports at least once a week beforethe injury. At the follow-up examination, 16 (66.7%)had returned to their former level of activity. In thesurgically treated group, 4 (16.4%) had to reducetheir level of activity because of their AC joint injury.

Before the injury, 12 conservatively treated and 13surgically treated patients had performed manualwork or overhead work. At the time of the follow-upexamination, 14 patients in the conservative grouphad returned to their former level of activity at workwhereas 3 were still noticeably restricted in physicalactivity. In the surgically treated group, 23 patientshad returned to their former level of activity at workwhereas 1 (construction worker) had quit his formerjob.

All 41 patients were examined radiologically(Table IV). On the standard AP radiograph, themean coracoclavicular distance was 14.1 6 4.9mm in the conservatively treated group and 11.6 64.6 mm in the surgically treated group. The differencewas not significant (P > .05). On the stress radio-graphs, the mean coracoclavicular distance was15.9 6 4.9 mm in the conservatively treated groupand 12.1 6 4.6 mm in the surgically treated group.This difference was statistically significant (P < .05).

In the conservatively treated group, the mean widthof the AC joint was 8.8 6 5.2 mm on the standard APradiograph and 9.9 6 4.9 mm on the stress radio-graph. In the surgically treated group, the mean widthof the AC joint was 4.8 6 3.2 mm on the standard APradiograph and 5.3 6 3.7 mm on the stress radio-

graph. The differences between the 2 groups were sig-nificant with and without stress (P < .05).

All patients in the conservatively treated group hadosteophytes on the caudal side of the lateral clavicle.However, clinically, these were not symptomatic. Inthe surgically treated group, 13 of 24 patients hadradiologic signs of arthrosis, although clinicalsymptoms of arthrosis only occurred in 1 patient. Ineach group, there were 5 patients whose radiographsshowed radiologic signs of arthrosis on the uninjuredAC joint as well.

Radiologically noticeable calcifications of thecoracoclavicular ligaments occurred in 7 conserva-tively treated patients (41.2%) and 8 patients in thesurgically treated group (33.3%) (Figure 3). Nonewas clinically symptomatic.

DISCUSSION

The question of which treatment is best for acute ACdislocation is still controversial. Supporters of opera-tive treatment state that an optimal result can only beexpected if the AC joint is reconstructed anatomicallyas accurately as possible; the reason is that, afterconservative treatment, the remaining dislocationmay lead to persistent discomfort.6,11,16

These arguments are opposed by the sound resultsachieved after conservative treatment that have beenreported during recent years.9,12,15 These authorsemphasized that, while being able to achieve compa-rable results, conservative treatment does not exposethe patient to the various risks of surgery. Phillips

224 Gstettner et al J Shoulder Elbow SurgMarch/April 2008

Table IV Radiologic results: Coracoclavicular distance and AC joint width (Student t test)

Surgically treated group (n ¼ 24) Conservatively treated group (n ¼ 17)

Mean SD Mean SD P value

Coracoclavicular distance (mm)Injured side

Standard radiograph 11.6 4.6 14.1 4.9 .11Stress radiograph 12.1 4.6 15.9 4.9 .013*

Opposite sideStandard radiograph 8.5 3.0 8.7 3.7 .84Stress radiograph 8.8 2.6 9.8 3.7 .28

AC joint width (mm)Injured side

Standard radiograph 4.8 3.2 8.8 5.2 .004*Stress radiograph 5.3 3.7 9.9 4.9 .001*

Opposite sideStandard radiograph 3.0 1.8 3.6 2.0 .27Stress radiograph 3.2 1.9 3.8 2.0 .34

AC joint index (no scale) 0.79 0.53 0.49 0.31 .03*

*Statistically significant.

et al12 ultimately advised against surgical treatment intheir meta-analysis on this subject.

A major flaw in the ongoing discussion of thetreatment of AC dislocation is the lack of use of theRockwood classification of AC joint injuries, as faras selective criteria are concerned.1,9,12,15,17 Theinformative value of the results of a study on this topicis considerably less if there are several types ofRockwood injuries included in the compared studygroups, even if all of the injuries in question areclassified as Tossy type III. We, therefore, explicitlyconcentrated on Rockwood type III injuries. Althoughit is possible to compare different surgical techniqueswith each other, it should also be made clear thatwhen comparing surgical treatment on the wholewith conservative treatment by meta-analysis,conclusions must be drawn carefully. Different surgicaltechniques vary considerably with regard to the resultsreported, the concept, the advantages, and thedrawbacks. Therefore, these should not be groupedtogether randomly.

In our opinion, the advantage of the hook platecompared with other techniques, such as tension-band wiring or the Bosworth screw, is the fact that,with the hook plate technique, no rigid fixation isdone between the coracoid and the clavicle, as withthe Bosworth screw, or between the coracoid andthe acromion, as with tension-band wiring. This factallows the hook plate to be left in place for a longerperiod of time than other implants (3 months in ourtreatment regimen). Thus, the capsule and the coraco-clavicular ligaments are given a longer time to healsufficiently, whereas other implants have to beremoved much earlier (eg, after 6 weeks). A furtherbenefit of this nonrigid fixation is that patients are

allowed to abduct the arm actively 4 weeks aftersurgery despite the implant still being in place. In com-parison to surgical techniques using polydioxanonebands for augmentation and reduction, the need fora second operation to remove the implant may beconsidered as a drawback.

A drawback of all surgical techniques, ascompared with conservative therapy, is the possibilityof complications. In our study, 3 patients had compli-cations, 2 of them needing revision. This means thatcomplications occurred in 11% of the patients, withrevision necessary in 7%.

The healing of the torn coracoclavicular ligamentsdepends on the development of rigid scar tissue. Thisbeing the decisive factor, a lack of mechanical

Figure 3 Calcifications of coracoclavicular ligaments, as shownhere, were seen in both study groups.

J Shoulder Elbow Surg Gstettner et al 225Volume 17, Number 2

stability in the coracoclavicular ligaments will lead topersistent discomfort, regardless of the treatment.

Excellent results in the treatment of Rockwood typeIII injuries can be achieved with both conservativetreatment and surgical treatment, as this study hasshown. Nonetheless, it must be pointed out that, inour study, the mean results in the surgically treatedgroup were better than those in the conservativelytreated group. The mean Constant score of theshoulder in question was significantly higher and themean score difference between both shoulders wassignificantly smaller in the surgically treated groupthan they were in the conservatively treated group.The difference in the Constant score between thegroups was caused mostly by the results in the subcat-egories of pain and power (which was measured byuse of a dynamometer in an examiner-independentway). The range of movement was very good in themajority of the patients, independent of the treatmentthat they received.

With regard to the 2 patient-validated scores (SSTand OSS), no statistical significance could be shownbetween the 2 groups. Nevertheless, the surgicalgroup achieved better mean scores, as well as a higherrate of excellent and good results, than the conserva-tively treated group.

Thus we believe that the significant difference in theConstant score and the radiologic results offersa certain clinical relevance that should not be disre-garded. From this perspective, surgical interventionto repair and suture the coracoclavicular ligamentsseems reasonable. The final decision for surgical treat-ment should be made individually for each patient,after consideration of the patient’s personal demands.

In conclusion, a diagnosis via the Rockwood classi-fication is indispensable for the appropriate treatmentof AC dislocations. To detect a horizontal dislocationof the lateral clavicle, an axillary radiograph shouldalways be obtained.

In our study, surgical treatment by use of a hookplate achieved better results than conservativetherapy. Surgery, therefore, seems to be indicated inRockwood type III injuries, especially when dealingwith younger and physically active patients, whosedemands often consist of not only the need for a freerange of movement but also the capability for goodpower.

In comparison to other means of fixation, theadvantage of the hook plate is that it can remain inthe shoulder without problems for months, thus giving

the coracoclavicular ligaments enough time to healsufficiently.

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