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Delaminated rotator cuff tear: extension of delamination and cuff integrity after arthroscopic rotator cuff repair
J Shoulder Elbow Surg (2014) -, 1-8
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Delaminated rotator cuff tear: extension of delamination and cuff integrity after arthroscopic rotator cuff repair Heui-Chul Gwak, MDa, Chang-Wan Kim, MDa, Jung-Han Kim, MDa,*, Hye-Jeung Choo, MDb, Seung-Yeob Sagong, MDa, John Shinc a
Department of Orthopaedics, Busan Paik Hospital, College of Medicine, Inje University, Busan, South Korea Department of Radiology, Busan Paik Hospital, College of Medicine, Inje University, Busan, South Korea c Medical Student, Icahn School of Medicine at Mount Sinai, New York, NY, USA b
Background: The purpose of this study was to evaluate the extension of delamination and the cuff integrity after arthroscopic repair of delaminated rotator cuff tears. Methods: Sixty-five patients with delaminated rotator cuff tears were retrospectively reviewed. The delaminated tears were divided into full-thickness delaminated tears and partial-thickness delaminated tears. To evaluate the medial extension, we calculated the coronal size of the delaminated portion. To evaluate the posterior extension, we checked the tendon involved. Cuff integrity was evaluated by computed tomography arthrography. Results: The mean medial extension in the full-thickness and partial-thickness delaminated tears was 18.1 6.0 mm and 22.7 6.3 mm, respectively (P ¼ .0084). The posterior extension into the supraspinatus and the infraspinatus was 36.9% and 32.3%, respectively, in the full-thickness delaminated tears, and it was 27.7% and 3.1%, respectively, in the partial-thickness delaminated tears (P ¼ .0043). With regard to cuff integrity, 35 cases of anatomic healing, 10 cases of partial healing defects, and 17 cases of retear were detected. Among the patients with retear and partial healing of the defect, all the partially healed defects showed delamination. Three retear patients showed delamination, and 14 retear patients did not show delamination; the difference was statistically significant (P ¼ .0001). Conclusion: The full-thickness delaminated tears showed less medial extension and more posterior extension than the partial-thickness delaminated tears. Delamination did not develop in retear patients, but delamination was common in the patients with partially healed defects. Level of evidence: Level IV, Case Series, Treatment Study. Ó 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. Keywords: Delamination; rotator cuff tear; extension; cuff integrity
IRB approval (No.14-0031) was given by Inje University Busan Paik Hospital. *Reprint requests: Jung-Han Kim, MD, Department of Orthopaedic Surgery, College of Medicine, Inje University Busan Paik Hospital, 633165, Gaegeum 2-dong, Busanjin-gu, Busan 614-735, South Korea. E-mail address: [email protected] (J.-H. Kim).
A delaminated rotator cuff tear is considered a form of degeneration within the tendon; it generally refers to a horizontal tear occurring between rotator cuff layers.7 The incidence of delaminated rotator cuff tears ranged from 38% to 82% in previous reports.1,5,12,17 Han et al7 reported
1058-2746/$ - see front matter Ó 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. http://dx.doi.org/10.1016/j.jse.2014.09.027
2 that the incidence of posterior delamination in rotator cuff tears was extremely high (92% overall incidence). Detailed studies of delaminated rotator cuff tears have demonstrated their importance as prognostic factors after arthroscopic rotator cuff repair.1,5 However, in previous studies, the authors used different definitions of the delaminated tear area.10,11,17,18,20 In addition, few studies have evaluated delaminated tear extension.1,11 Moreover, there are few studies of the retear rate after arthroscopic delaminated rotator cuff repair15,19 and no reports on the retear type. The specific aims of this study were to evaluate the extension of delamination and to evaluate the retear rate and type.
Materials and methods We evaluated rotator cuff tear patients who had undergone magnetic resonance imaging (MRI) at our institution before arthroscopic rotator cuff repair from April 2011 to April 2013. One hundred sixty-five patients were identified for potential inclusion. Twelve patients with glenohumeral arthritis, cuff tear arthropathy, previous shoulder operations, and acute traumatic rotator cuff tears were excluded. Twenty patients who had undergone MRI more than 30 days before the operation were also excluded. We defined a fullthickness delaminated tear as (1) a horizontally retracted tear of both the articular and bursal surfaces of the tendon, (2) disruption of the tendon extending from the bursal surface to the articular surface, (3) a distinguishable gap between the articular and bursal surfaces of the tendon, (4) and interstitial horizontal splitting (Fig. 1). Partial-thickness delaminated tears were defined as (1) horizontal retraction of either the articular or bursal surface of the tendon and (2) interstitial horizontal splitting (Fig. 2). An articular partialthickness delaminated tear was defined as the articular surface of the tendon retracted in the partial-thickness delaminated tear. A bursal partial-thickness delaminated tear was defined as the bursal surface of the tendon retracted in the partial-thickness delaminated tear. We defined the medial extension of the delamination as the sum of (1) the gap between the articular and bursal surface layers and (2) the intrasubstance cleavage between the 2 layers. In addition, we defined the posterior extension as the distance from the most anterior portion that showed delamination to the last posterior portion that showed continuous delamination with the anterior portion of delamination. A radiologist who specialized in musculoskeletal imaging evaluated the magnetic resonance images and selected 77 patients whose radiologic findings fit the definition of a delaminated rotator cuff tear. We also evaluated arthroscopic findings and selected 73 patients whose arthroscopic findings fit the definition of a delaminated tear. In cases of articular partial-thickness delaminated tears, we confirmed a delaminated tear after carrying out bursal-side debridement. Four patients were excluded because of lack of agreement between the authors and the radiologist about the presence of delamination. Moreover, 8 patients were excluded because of no agreement between the authors and the radiologist about the classification of full- and partialthickness delaminated tears. Finally, 65 patients with delaminated tears were selected on the basis of agreement between the authors and the radiologist. The mean age of the patients was 59.9 6.4 years. Twentyfive patients (38.5%) were male, and 40 patients (61.5%) were
H.-C. Gwak et al. female. For the evaluation of medial and posterior extension of delamination, we selected coronal oblique magnetic resonance images from the anterior image that showed the most appropriate delaminated tears to the last image that showed continuous delamination with the anterior portion of delamination. In the full-thickness delaminated tears, the gap between the bursal surface and the articular surface layers was calculated by measuring the distance between the lateral margin of the bursal and articular surface layers with a caliper supplied by the picture archiving and communication system (PACS) console (Maroview; Marotech, Seoul, South Korea). The intrasubstance cleavage was calculated by measuring the distance of the high transverse signal from the lateral margin of the more retracted layer to the medial margin of the high signal (Fig. 3, A). In the partial-thickness delaminated rotator cuff tears, the distance between the most lateral side of the torn layer and the intact layer was calculated with the measurement caliper of the PACS console (Maroview; Marotech). The intrasubstance cleavage was calculated by measuring the high transverse signal distance from the lateral margin of the more retracted layer to the medial margin of the high signal between the 2 layers (Fig. 3, B). Among the selected coronal oblique images that showed delaminated tears, we selected the image that showed the greatest sum value for both the gap between the 2 layers and the intrasubstance cleavage. We then evaluated the medial extension of delamination in the selected image. To evaluate the posterior extension of delamination in the involved tendon, we used not only coronal oblique images but also sagittal oblique images. We also determined whether the full- or partial-thickness delaminated tear changed to another type of tear as the delamination extended posteriorly. Finally, the radiologic outcome was evaluated by computed tomography (CT) arthrography 6 months after the operation. Tendon healing was classified as anatomic healing, a partially healed defect, and retear.14 In the case of anatomic healing, we evaluated whether the intrasubstance cleavage had disappeared (Fig. 4). In the case of retears and partially healed defects, we evaluated whether the delamination had developed again (Fig. 5).
Surgical methods All patients had received nonoperative treatment for at least 3 months. The indication for surgery was failure of nonoperative treatment, which included physical therapy and corticosteroid injections. All the arthroscopic procedures were performed by a single surgeon. The patient was placed in a beach chair position, sitting at an angle of 70 . The posterior portal and anterior portal of the shoulder were established, and the glenohumeral joint was examined through these portals and accessory portals. In the delaminated tears, the surgeon debrided the delaminated surface of the torn rotator cuff to improve tendon healing, passed the suture through the whole cuff, and tied the sutures by the so-called arthroscopic en mass suture bridge technique.15 The articular partial-thickness delaminated rotator cuff was repaired by the double-row suture bridge method after tear completion. In all cases, the patient’s arm remained in a sling for 6 weeks, and only passive range of motion was allowed during this period. At 6 weeks, gradual full active motion was instituted, progressing to resistive strengthening, which was continued for a total of 3 to 4 months.
The delaminated rotator cuff tear
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Figure 1 Preoperative MRI and intraoperative arthroscopic findings of full-thickness delaminated rotator cuff tear. (A) Coronal oblique MRI showed horizontally retracted tear of both the articular and bursal surfaces of the tendon (white arrows) with intrasubstance cleavage (black arrow). (B) Intraoperative arthroscopy showed horizontally retracted tear of both layers (black arrows) and interstitial horizontal splitting (white arrow).
Figure 2 Preoperative MRI and intraoperative arthroscopic findings of partial-thickness delaminated rotator cuff tear. (A) Coronal oblique MRI showed horizontally retracted tear of either the articular or bursal surface of the tendon (white arrow) with intrasubstance cleavage (black arrow). (B) Intraoperative arthroscopy showed horizontally retracted bursal layers (black arrow) and interstitial horizontal splitting (white arrow).
Statistical analysis The gap between the articular and bursal surface layers, the intrasubstance cleavage, and the mediolateral size of the delamination were evaluated with Wilcoxon rank sum test and a t test. The type of tendon involved and the change to another type of tear as the delamination extended posteriorly between the partial- and full-thickness delaminated tears were analyzed by Fisher exact test and a c2 test. For comparison of the radiologic outcomes between the full- and partial-thickness delaminated tears, Fisher exact test was used. Fisher exact test was also used to determine the statistical difference of the presence of delamination between the partially healed defects and retears. The k value for interobserver reliability was measured. All statistical analyses were conducted with the SAS 9.3 (SAS Institute, Cary, NC, USA) software, and the critical value for significance was set at P < .05.
partial delaminated tears, 10 patients (15.4%) showed an articular partial-thickness delaminated tear, and 10 patients (15.4%) showed a bursal partial-thickness delaminated tear. The k value for interobserver reliability in the detection of delamination was 0.939, and the k value for interobserver reliability according to the type of delamination (i.e., full or partial delamination) was 0.858.
Medial extension of delamination The medial extension of delamination is summarized in Table I. The mean mediolateral size of the delamination was 18.1 6.0 mm in the full-thickness delaminated tears and 22.7 6.3 mm in the partial-thickness delaminated tears. This difference was statistically significant (P ¼ .0084).
Results
Posterior extension of delamination
Among 65 delaminated rotator cuff tear patients, 20 (30.8%) showed a partial-thickness delaminated tear and 45 (69.2%) showed a full-thickness delaminated tear. In the
The posterior extension of delamination is summarized in Table II. Posterior extension of delamination into the infraspinatus tendon was more common in full-thickness
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H.-C. Gwak et al.
Figure 3 (A) In full-thickness delaminated tear, intrasubstance cleavage (a) was calculated by measuring the distance of the high transverse signal from the lateral margin of the more retracted layer to the medial margin of high signal between the 2 layers, and the gap between bursal surface and articular surface (b) was calculated by measuring the distance between the lateral margin of bursal and articular layers. (B) In partial-thickness delaminated rotator cuff tear, intrasubstance cleavage (a) was calculated by measuring the distance of the high transverse signal from the lateral margin of the more retracted layer to the medial margin of high signal between the 2 layers, and the gap between articular and bursal layers (b) was calculated by measuring the distance between the most lateral side of torn layer and intact layer.
Figure 4 CT arthrogram 6 months after the operation showed remaining intrasubstance cleavage (left) and no cleavage (right) in anatomic healed cases.
delaminated tears than in partial-thickness delaminated tears, and this difference was statistically significant (P ¼ .0043). Among the 45 cases of full-thickness delaminated tears, 2 patients (4.4%) with extension of the tear into the supraspinatus tendon showed changes from a full-thickness delaminated tear to a partial-thickness delaminated tear, and 12 patients (26.7%) with extension of the tear into the infraspinatus tendon showed changes from a full-thickness delaminated tear to a partial-thickness delaminated tear as the delamination extended posteriorly. There was a statistically significant difference in the change to another type of tear as the delamination extended posteriorly in the fullthickness delaminated tears (P ¼ .0004). Among the 20 cases of partial-thickness delaminated tears, none of the tears changed to another type as the delamination extended posteriorly (Table III).
Radiologic results after arthroscopic rotator cuff repair Among the 65 delaminated tear patients, 62 underwent CT arthrography 6 months postoperatively. Radiologic results after repair are summarized in Table IV. With regard to the presence of cleavage, there were no statistically significant differences in the anatomic healing between the partial- and full-thickness delaminated tears (P ¼ .6855). With regard to the presence of delamination in the partially healed defect, there was no statistically significant difference between the partial- and full-thickness delaminated tears (P ¼ 1.00). There were also no statistically significant differences in the presence of delamination in retears between the partialand full-thickness delaminated tears (P ¼ .5412). All the patients (10 patients; 100%) with partial healing of the defect showed delamination, and 3 of 17 (17.6%)
The delaminated rotator cuff tear
Figure 5
5
CT arthrogram 6 months after the operation showed delamination (left) and no delamination (right) in a case of retear.
Table I Gap between articular and bursal layers, intrasubstance gap, and medial extension of delamination in fulland partial-thickness delaminated tears Gap between Intrasubstance Mediolateral size (mm) articular and gap (mm) bursal layers (mm) FT delaminated 10.3 (4.9) tear PT delaminated 9.1 (5.0) tear P value .3859
7.9 (4.3)
18.1 (6.0)
13.6 (5.5)
22.7 (6.3)
.0001
.0084
FT, full thickness; PT, partial thickness.
Table II Involved tendon in full- and partial-thickness delaminated tears FT delaminated tear PT delaminated tear
SST
SST þ IST
P value
24 (36.9%) 18 (27.7%)
21 (32.3%) 2 (3.1%)
.0043
SST, supraspinatus tendon; SST þ IST, supraspinatus tendon þ infraspinatus tendon; FT, full thickness; PT, partial thickness.
retear patients showed delamination. Fourteen patients (82.4%) with retears did not show delamination. There were statistically significant differences in development of delamination between the patients with partial healing of the defect and retear patients (P ¼ .0001) (Table V).
Discussion A delaminated tear is considered a form of degeneration within the tendon and is generally referred to as a
Table III Delaminated tear type change in full- and partialthickness delaminated tears FT delaminated tear Change () Change (þ) Articular Bursal PT delaminated tear Change () Change (þ)
SST
SST þ IST
24 22 2 2 0 18 18 0
21 9 12 10 2 2 2 0
(48.9%) (4.4%)
(90.0%) (0.0%)
P value .0004
(20.0%) (26.7%)
1.00 (10.0%) (0.0%)
SST, supraspinatus tendon; SST þ IST, supraspinatus tendon þ infraspinatus tendon; FT, full thickness; PT, partial thickness. Articular, articular partial-thickness delaminated rotator cuff tear; Bursal, bursal partial-thickness delaminated rotator cuff tear.
horizontal intrasubstance tear, with partial intratendinous fiber retraction.4,6,16,18 Shear stress between the bursal and articular layers seems to play a role in its pathogenesis. In the evaluation of rotator cuff tears that contained a laminated portion, Ellman4 and Sonnabend et al18 both reported a gap between the articular surface layer fibers and the bursal surface fibers. Sonnabend et al18 also found that a portion of the delaminated torn tendon was split and that a synovium-like cellular lining was present in the split area. Likewise, in this study, a gap between the articular and bursal surface layers and an intrasubstance cleavage between the two layers were characteristics of the delaminated rotator cuff tear. MacDougal and Todhunter11 defined a delaminated tear as cleavage tearing >5 mm based on arthroscopic findings. They used this criterion to evaluate the presence of delamination and did not grade the degree or the extent of delamination. In the current study, we divided the delaminated tears into partial-thickness and full-thickness delaminated tears according to the degree of delamination. Moreover, we characterized the extension type of
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H.-C. Gwak et al. Table IV Radiologic outcomes in full- and partial-thickness delaminated tears FT delaminated PT delaminated P tear tear value Anatomic heal Cleavage (þ) Cleavage () Partial heal Delamination Delamination Retear Delamination Delamination
(þ) () (þ) ()
24 17 7 7 7 0 13 3 10
(48.6%) (20.0%) (70.0%) (0.0%) (17.7%) (58.8%)
11 9 (25.7%) 2 (5.7%) 3 3 (30.0%) 0 (0.0%) 4 0 (0.0%) 4 (23.5%)
.6855
1.00
.5412
FT, full thickness; PT, partial thickness.
Table V Presence of delamination in patients with partial healing and retear Delamination (þ) Delamination ()
Partial healing
Retear
P value
10 0
3 14
.0001
delamination as medial extension and posterior extension. The tears with partial delamination showed greater medial extension than those with full delamination in our study. We could not determine the mechanism underlying the difference in the medial extension of delamination between the partial- and full-thickness delaminated tears. However, we think that the mean retraction and cleavage are important factors in repair of delaminated torn tendons. In delaminated tears, the retraction of articular and bursal surface layer is different.11,12,17,18 Thus, there may be tension mismatch while repairing a delaminated tendon. In our study, the mean gap between the articular and bursal layers was 10.3 4.9 mm in the full-thickness delaminated tears and 9.1 5.0 mm in the partial-thickness delaminated tears. However, many cases exceeded the mean value. Preoperative evaluation of this gap will be useful for finding the deeper articular layer operatively and for selecting the appropriate operative repair technique. Moreover, in this study, intrasubstance cleavage extended more medially from the margin of the retracted layer. This means that part of the intrasubstance cleavage may not have closed properly after the rotator cuff repair. Zilber et al22 stated that an infraspinatus intratendinous cleavage does not affect the status of the supraspinatus muscle. However, they also suggested that it may be difficult to ascertain the healing of delamination in infraspinatus tears. This may be the case in this study, with intratendinous cleavage existing medial to the layer of the delaminated tears. Such cleavage might be overlooked if a careful evaluation is not undertaken. This might result in intratendinous tears not healing and expose the tendon to persistent shear stress.
In this study, we also evaluated the posterior extension of delamination. Among the delaminated tears, posterior extension was common in the full-thickness delaminated tears compared with the partial-thickness delaminated tears. Flurin et al5 reported delamination extension into the supraspinatus in 31% of cases and delamination extension into the infraspinatus in 26% of cases. Han et al7 suggested that posterior delamination is detected differently according to the portal used for access. They also noted that the articular surface layer could be missed because it is retracted more than the bursal surface layer. In this study, 21 cases were extended into the infraspinatus. Moreover, among these cases, 12 changed from a full-thickness delaminated tear to a partial-thickness delaminated tear. Ten of 12 cases changed to an articular partial-thickness delaminated tear as the tear extended posteriorly. Such tears might be difficult to find operatively because the torn articular layer is hidden under the intact bursal surface layer. If preoperative MRI is not performed, these delaminated tears might be overlooked on the basis of arthroscopic findings alone. In cases of preoperative suspicion of a torn articular layer, selection of an appropriate portal and debridement of the bursal layer are needed to detect this layer. In this study, we evaluated cuff continuity after repair of the delaminated rotator cuff. Park et al15 suggested that the incidence of retear was 25% in delaminated rotator cuff repair with use of the en mass suture technique. In this study, the incidence of retear and partial healing of the defect was 27.4% and 16.1%, respectively, after en mass repair of the delaminated rotator cuffs. Park et al15 evaluated only massive rotator cuff tears and evaluated the cuff continuity by ultrasound, dividing their findings into healed and retear. In our study, we evaluated the repair of all types of rotator cuff tears, including partial-thickness tears. We evaluated cuff continuity by CT arthrography and divided the cuff continuity into anatomic healing, partially healed defect, and retears. In our study, the retear and partially healed defect cases showed difference in recurring delamination after arthroscopic repair. To the best of our knowledge, no previous literature has described recurring of delamination after rotator cuff repair. Thus, we cannot explain the cause of this finding and compare our results with those of similar studies. However, we speculate that this difference might be due to tension mismatch between the layers after rotator cuff repair, with different tension between the layers after repair potentially leading to partial healing and delamination. Further evaluation will be needed to shed light on this issue. Interestingly, 26 of 35 anatomically healed cases (74.3%) showed remaining intrasubstance cleavage after bone to tendon healing. Park et al15 stated that the en mass operative technique was useful because it unites the delamination and prevents shear force. However, in our study, although we used this technique, intrasubstance cleavage remained in a high proportion of the patients. The
The delaminated rotator cuff tear clinical significance of this finding is unclear. However, this might affect the remaining tendon and long-term clinical outcomes. This study has some limitations. First, we selected only study subjects who underwent MRI and surgery in our institution. In addition, the subjects were selected on the basis of agreement between the radiologist and the authors. Thus, not all delaminated rotator cuff tear repair patients were included in our study. However, the purpose of this study was to evaluate the extension of delamination, and the protocol for shoulder MRI differs, as do MRI machines, depending on the institution. Therefore, when evaluating the extension of delamination, we did not compare magnetic resonance images taken in other institutions. Moreover, although arthroscopy is supposed to be the ‘‘gold standard’’ for detection of delaminated tears, some cases in more medially retracted layers and posteriorly extended tears may be missed in arthroscopic findings. Thus, we double-checked the presence of delamination with arthroscopic and MRI findings. Second, we used radiologic imaging to evaluate the dimension of delamination. As a result, the arthroscopically measured value could not be determined. Thus, these values are not representative of the actual values. Moreover, some tears that may have extended into the infraspinatus might not have been detected because of the slice thickness. However, in real arthroscopic repairs, fraying edges of torn tears are debrided. Therefore, arthroscopically measured values are not representative of the actual values. It is difficult to calculate the dimension of delamination from arthroscopic findings, and the results are not constant. In contrast, although the evaluation of the dimension of delamination in MRI is largely dependent on the slicing cutting angle, this angle is constant; calculation of the dimension is easy, and the results are reproducible. In addition, we used sagittal oblique images as well as coronal oblique images to evaluate the posterior extension of the delamination. This might reduce the bias due to the cutting slice thickness. Third, retears were evaluated by CT arthrography 6 months postoperatively. The postoperative 6-month time is considered too soon to evaluate the continuity of repaired rotator cuff tears. Moreover, CT arthrography has a potential weakness in that bursal-side tears are not detected if contrast material is placed into the joint. However, our aim here was to determine the rate and type of retear. According to the literature,8,9,13 most retears develop in the first 6 months postoperatively, and many studies have reported using postoperative 6-month CT arthrography for the evaluation of the continuity of repaired rotator cuff tears.2,3,21 Further, long-term evaluations of rotator cuff repairs by MRI studies will be needed. Fourth, functional outcomes were not included in this study. Therefore, whether delaminated tears affect clinical outcomes and whether delaminated retear and nondelaminated retears show different clinical outcomes could not be evaluated. Further evaluation and study will be needed to address these issues. Finally, the size of our study group
7 was relatively small, and we could not perform a power analysis. Therefore, the results might be underpowered with regard to differences in the extension of delamination and retear type between full- and partial-thickness delaminated tears. The results should be interpreted with care.
Conclusion The full-thickness delaminated tears showed less medial extension and more posterior extension than the partialthickness delaminated tears. In the full-thickness delaminated tears, changes to articular partial-thickness delaminated tears as the tears extended posteriorly were common. Anatomic healing, partially healed defects, and retears were 53.9%, 15.4%, and 26.2%, respectively. There were differences in the development of delamination between the partially healed defects and retear cases after arthroscopic repair. Moreover, intratendinous cleavage after healing was a common finding. Further studies are needed to determine the clinical relevance of these results.
Disclaimer The authors, their immediate families, and any research foundation with which they are affiliated have not received any financial payments or other benefits from any commercial entity related to the subject of this article.
Acknowledgment This work was supported by the National Research Foundation of Korea (NRF) funded by the Ministry of Education Science and Technology (NRF2012R1A1A1012384).
References 1. Boileau P, Brassart N, Watkinson DJ, Carles M, Hatzidakis AM, Krishnan SG. Arthroscopic repair of full-thickness tears of the supraspinatus: does the tendon really heal? J Bone Joint Surg Am 2005;87:1229-40. http://dx.doi.org/10.2106/JBJS.D.02035 2. Charousset C, Bellaiche L, Kalra K, Petrover D. Arthroscopic repair of full-thickness rotator cuff tears: is there tendon healing in patients aged 65 years or older? Arthroscopy 2010;26:302-9. http://dx.doi.org/ 10.1016/j.arthro.2009.08.027 3. Charousset C, Grimberg J, Duranthon LD, Bellaiche L, Petrover D, Kalra K. The time for functional recovery after arthroscopic rotator cuff repair: correlation with tendon healing controlled by computed tomography arthrography. Arthroscopy 2008;24:25-33. http://dx.doi. org/10.1016/j.arthro.2007.07.023
8 4. Ellman H. Diagnosis and treatment of incomplete rotator cuff tears. Clin Orthop Relat Res 1990:64-74. 5. Flurin PH, Landreau P, Gregory T, Boileau P, Brassart N, Courage O, et al. Arthroscopic repair of full-thickness cuff tears: a multicentric retrospective study of 576 cases with anatomical assessment. Rev Chir Orthop Reparatrice Appar Mot 2005;91:31-42. 6. Fukuda H. The management of partial-thickness tears of the rotator cuff. J Bone Joint Surg Br 2003;85:3-11. http://dx.doi.org/10.1302/ 0301-620X.85B1.13846 7. Han Y, Shin JH, Seok CW, Lee CH, Kim SH. Is posterior delamination in arthroscopic rotator cuff repair hidden to the posterior viewing portal? Arthroscopy 2013;29:1740-7. http://dx.doi.org/10.1016/j. arthro.2013.08.021 8. Iannotti JP, Deutsch A, Green A, Rudicel S, Christensen J, Marraffino S, et al. Time to failure after rotator cuff repair: a prospective imaging study. J Bone Joint Surg Am 2013;95:965-71. http:// dx.doi.org/10.2106/JBJS.L.00708 9. Kluger R, Bock P, Mittlbock M, Krampla W, Engel A. Long-term survivorship of rotator cuff repairs using ultrasound and magnetic resonance imaging analysis. Am J Sports Med 2011;39:2071-81. http://dx.doi.org/10.1177/0363546511406395 10. Lee SY, Lee JK. Horizontal component of partial-thickness tears of rotator cuff: imaging characteristics and comparison of ABER view with oblique coronal view at MR arthrography initial results. Radiology 2002;224:470-6. http://dx.doi.org/10.1148/radiol. 2241011261 11. MacDougal GA, Todhunter CR. Delamination tearing of the rotator cuff: prospective analysis of the influence of delamination tearing on the outcome of arthroscopically assisted mini open rotator cuff repair. J Shoulder Elbow Surg 2010;19:1063-9. http://dx.doi.org/10.1016/j. jse.2009.12.020 12. Matsuki K, Murate R, Ochiai N, Ogino S. Delamination observed in full-thickness rotator cuff tears [in Japanese]. Shoulder Joint (Katakansetsu) 2005;29:603-6.
H.-C. Gwak et al. 13. Miller BS, Downie BK, Kohen RB, Kijek T, Lesniak B, Jacobson JA, et al. When do rotator cuff repairs fail? Serial ultrasound examination after arthroscopic repair of large and massive rotator cuff tears. Am J Sports Med 2011;39:2064-70. http://dx.doi.org/10.1177/ 0363546511413372 14. Papalia R, Franceschi F, Vasta S, Zampogna B, Maffulli N, Denaro V. Single- and double-row repair for rotator cuff tearsdbiology and mechanics. Med Sport Sci 2012;57:122-41. http://dx.doi.org/10.1159/ 000328902 15. Park JY, Lhee SH, Oh KS, Moon SG, Hwang JT. Clinical and ultrasonographic outcomes of arthroscopic suture bridge repair for massive rotator cuff tear. Arthroscopy 2013;29:280-9. http://dx.doi.org/10. 1016/j.arthro.2012.09.008 16. Resnick D. Diagnosis of bone and joint disorders. 4th ed. Philadelphia: Saunders; 2002. p. 3100-2 (ISBN No. 978-0721689210). 17. Sonnabend DH, Watson EM. Structural factors affecting the outcome of rotator cuff repair. J Shoulder Elbow Surg 2002;11:212-8. http://dx. doi.org/10.1067/mse.2002.122272 18. Sonnabend DH, Yu Y, Howlett CR, Harper GD, Walsh WR. Laminated tears of the human rotator cuff: a histologic and immunochemical study. J Shoulder Elbow Surg 2001;10:109-15. 19. Sugaya H, Maeda K, Matsuki K, Moriishi J. Repair integrity and functional outcome after arthroscopic double-row rotator cuff repair. A prospective outcome study. J Bone Joint Surg Am 2007;89:953-60. http://dx.doi.org/10.2106/JBJS.F.00512 20. Walz DM, Miller TT, Chen S, Hofman J. MR imaging of delamination tears of the rotator cuff tendons. Skeletal Radiol 2007;36:411-6. http:// dx.doi.org/10.1007/s00256-006-0265-3 21. Wu XL, Briggs L, Murrell GA. Intraoperative determinants of rotator cuff repair integrity: an analysis of 500 consecutive repairs. Am J Sports Med 2012;40:2771-6. http://dx.doi.org/10.1177/0363546512462677 22. Zilber S, Carillon Y, Lapner PC, Walch G, Nove-Josserand L. Infraspinatus delamination does not affect supraspinatus tear repair. Clin Orthop Relat Res 2007;458:63-9.
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Delaminated rotator cuff tear: extension of delamination and cuff integrity after arthroscopic rotator cuff repair Heui-Chul Gwak, MDa, Chang-Wan Kim, MDa, Jung-Han Kim, MDa,*, Hye-Jeung Choo, MDb, Seung-Yeob Sagong, MDa, John Shinc a
Department of Orthopaedics, Busan Paik Hospital, College of Medicine, Inje University, Busan, South Korea Department of Radiology, Busan Paik Hospital, College of Medicine, Inje University, Busan, South Korea c Medical Student, Icahn School of Medicine at Mount Sinai, New York, NY, USA b
Background: The purpose of this study was to evaluate the extension of delamination and the cuff integrity after arthroscopic repair of delaminated rotator cuff tears. Methods: Sixty-five patients with delaminated rotator cuff tears were retrospectively reviewed. The delaminated tears were divided into full-thickness delaminated tears and partial-thickness delaminated tears. To evaluate the medial extension, we calculated the coronal size of the delaminated portion. To evaluate the posterior extension, we checked the tendon involved. Cuff integrity was evaluated by computed tomography arthrography. Results: The mean medial extension in the full-thickness and partial-thickness delaminated tears was 18.1 6.0 mm and 22.7 6.3 mm, respectively (P ¼ .0084). The posterior extension into the supraspinatus and the infraspinatus was 36.9% and 32.3%, respectively, in the full-thickness delaminated tears, and it was 27.7% and 3.1%, respectively, in the partial-thickness delaminated tears (P ¼ .0043). With regard to cuff integrity, 35 cases of anatomic healing, 10 cases of partial healing defects, and 17 cases of retear were detected. Among the patients with retear and partial healing of the defect, all the partially healed defects showed delamination. Three retear patients showed delamination, and 14 retear patients did not show delamination; the difference was statistically significant (P ¼ .0001). Conclusion: The full-thickness delaminated tears showed less medial extension and more posterior extension than the partial-thickness delaminated tears. Delamination did not develop in retear patients, but delamination was common in the patients with partially healed defects. Level of evidence: Level IV, Case Series, Treatment Study. Ó 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. Keywords: Delamination; rotator cuff tear; extension; cuff integrity
IRB approval (No.14-0031) was given by Inje University Busan Paik Hospital. *Reprint requests: Jung-Han Kim, MD, Department of Orthopaedic Surgery, College of Medicine, Inje University Busan Paik Hospital, 633165, Gaegeum 2-dong, Busanjin-gu, Busan 614-735, South Korea. E-mail address: [email protected] (J.-H. Kim).
A delaminated rotator cuff tear is considered a form of degeneration within the tendon; it generally refers to a horizontal tear occurring between rotator cuff layers.7 The incidence of delaminated rotator cuff tears ranged from 38% to 82% in previous reports.1,5,12,17 Han et al7 reported
1058-2746/$ - see front matter Ó 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. http://dx.doi.org/10.1016/j.jse.2014.09.027
2 that the incidence of posterior delamination in rotator cuff tears was extremely high (92% overall incidence). Detailed studies of delaminated rotator cuff tears have demonstrated their importance as prognostic factors after arthroscopic rotator cuff repair.1,5 However, in previous studies, the authors used different definitions of the delaminated tear area.10,11,17,18,20 In addition, few studies have evaluated delaminated tear extension.1,11 Moreover, there are few studies of the retear rate after arthroscopic delaminated rotator cuff repair15,19 and no reports on the retear type. The specific aims of this study were to evaluate the extension of delamination and to evaluate the retear rate and type.
Materials and methods We evaluated rotator cuff tear patients who had undergone magnetic resonance imaging (MRI) at our institution before arthroscopic rotator cuff repair from April 2011 to April 2013. One hundred sixty-five patients were identified for potential inclusion. Twelve patients with glenohumeral arthritis, cuff tear arthropathy, previous shoulder operations, and acute traumatic rotator cuff tears were excluded. Twenty patients who had undergone MRI more than 30 days before the operation were also excluded. We defined a fullthickness delaminated tear as (1) a horizontally retracted tear of both the articular and bursal surfaces of the tendon, (2) disruption of the tendon extending from the bursal surface to the articular surface, (3) a distinguishable gap between the articular and bursal surfaces of the tendon, (4) and interstitial horizontal splitting (Fig. 1). Partial-thickness delaminated tears were defined as (1) horizontal retraction of either the articular or bursal surface of the tendon and (2) interstitial horizontal splitting (Fig. 2). An articular partialthickness delaminated tear was defined as the articular surface of the tendon retracted in the partial-thickness delaminated tear. A bursal partial-thickness delaminated tear was defined as the bursal surface of the tendon retracted in the partial-thickness delaminated tear. We defined the medial extension of the delamination as the sum of (1) the gap between the articular and bursal surface layers and (2) the intrasubstance cleavage between the 2 layers. In addition, we defined the posterior extension as the distance from the most anterior portion that showed delamination to the last posterior portion that showed continuous delamination with the anterior portion of delamination. A radiologist who specialized in musculoskeletal imaging evaluated the magnetic resonance images and selected 77 patients whose radiologic findings fit the definition of a delaminated rotator cuff tear. We also evaluated arthroscopic findings and selected 73 patients whose arthroscopic findings fit the definition of a delaminated tear. In cases of articular partial-thickness delaminated tears, we confirmed a delaminated tear after carrying out bursal-side debridement. Four patients were excluded because of lack of agreement between the authors and the radiologist about the presence of delamination. Moreover, 8 patients were excluded because of no agreement between the authors and the radiologist about the classification of full- and partialthickness delaminated tears. Finally, 65 patients with delaminated tears were selected on the basis of agreement between the authors and the radiologist. The mean age of the patients was 59.9 6.4 years. Twentyfive patients (38.5%) were male, and 40 patients (61.5%) were
H.-C. Gwak et al. female. For the evaluation of medial and posterior extension of delamination, we selected coronal oblique magnetic resonance images from the anterior image that showed the most appropriate delaminated tears to the last image that showed continuous delamination with the anterior portion of delamination. In the full-thickness delaminated tears, the gap between the bursal surface and the articular surface layers was calculated by measuring the distance between the lateral margin of the bursal and articular surface layers with a caliper supplied by the picture archiving and communication system (PACS) console (Maroview; Marotech, Seoul, South Korea). The intrasubstance cleavage was calculated by measuring the distance of the high transverse signal from the lateral margin of the more retracted layer to the medial margin of the high signal (Fig. 3, A). In the partial-thickness delaminated rotator cuff tears, the distance between the most lateral side of the torn layer and the intact layer was calculated with the measurement caliper of the PACS console (Maroview; Marotech). The intrasubstance cleavage was calculated by measuring the high transverse signal distance from the lateral margin of the more retracted layer to the medial margin of the high signal between the 2 layers (Fig. 3, B). Among the selected coronal oblique images that showed delaminated tears, we selected the image that showed the greatest sum value for both the gap between the 2 layers and the intrasubstance cleavage. We then evaluated the medial extension of delamination in the selected image. To evaluate the posterior extension of delamination in the involved tendon, we used not only coronal oblique images but also sagittal oblique images. We also determined whether the full- or partial-thickness delaminated tear changed to another type of tear as the delamination extended posteriorly. Finally, the radiologic outcome was evaluated by computed tomography (CT) arthrography 6 months after the operation. Tendon healing was classified as anatomic healing, a partially healed defect, and retear.14 In the case of anatomic healing, we evaluated whether the intrasubstance cleavage had disappeared (Fig. 4). In the case of retears and partially healed defects, we evaluated whether the delamination had developed again (Fig. 5).
Surgical methods All patients had received nonoperative treatment for at least 3 months. The indication for surgery was failure of nonoperative treatment, which included physical therapy and corticosteroid injections. All the arthroscopic procedures were performed by a single surgeon. The patient was placed in a beach chair position, sitting at an angle of 70 . The posterior portal and anterior portal of the shoulder were established, and the glenohumeral joint was examined through these portals and accessory portals. In the delaminated tears, the surgeon debrided the delaminated surface of the torn rotator cuff to improve tendon healing, passed the suture through the whole cuff, and tied the sutures by the so-called arthroscopic en mass suture bridge technique.15 The articular partial-thickness delaminated rotator cuff was repaired by the double-row suture bridge method after tear completion. In all cases, the patient’s arm remained in a sling for 6 weeks, and only passive range of motion was allowed during this period. At 6 weeks, gradual full active motion was instituted, progressing to resistive strengthening, which was continued for a total of 3 to 4 months.
The delaminated rotator cuff tear
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Figure 1 Preoperative MRI and intraoperative arthroscopic findings of full-thickness delaminated rotator cuff tear. (A) Coronal oblique MRI showed horizontally retracted tear of both the articular and bursal surfaces of the tendon (white arrows) with intrasubstance cleavage (black arrow). (B) Intraoperative arthroscopy showed horizontally retracted tear of both layers (black arrows) and interstitial horizontal splitting (white arrow).
Figure 2 Preoperative MRI and intraoperative arthroscopic findings of partial-thickness delaminated rotator cuff tear. (A) Coronal oblique MRI showed horizontally retracted tear of either the articular or bursal surface of the tendon (white arrow) with intrasubstance cleavage (black arrow). (B) Intraoperative arthroscopy showed horizontally retracted bursal layers (black arrow) and interstitial horizontal splitting (white arrow).
Statistical analysis The gap between the articular and bursal surface layers, the intrasubstance cleavage, and the mediolateral size of the delamination were evaluated with Wilcoxon rank sum test and a t test. The type of tendon involved and the change to another type of tear as the delamination extended posteriorly between the partial- and full-thickness delaminated tears were analyzed by Fisher exact test and a c2 test. For comparison of the radiologic outcomes between the full- and partial-thickness delaminated tears, Fisher exact test was used. Fisher exact test was also used to determine the statistical difference of the presence of delamination between the partially healed defects and retears. The k value for interobserver reliability was measured. All statistical analyses were conducted with the SAS 9.3 (SAS Institute, Cary, NC, USA) software, and the critical value for significance was set at P < .05.
partial delaminated tears, 10 patients (15.4%) showed an articular partial-thickness delaminated tear, and 10 patients (15.4%) showed a bursal partial-thickness delaminated tear. The k value for interobserver reliability in the detection of delamination was 0.939, and the k value for interobserver reliability according to the type of delamination (i.e., full or partial delamination) was 0.858.
Medial extension of delamination The medial extension of delamination is summarized in Table I. The mean mediolateral size of the delamination was 18.1 6.0 mm in the full-thickness delaminated tears and 22.7 6.3 mm in the partial-thickness delaminated tears. This difference was statistically significant (P ¼ .0084).
Results
Posterior extension of delamination
Among 65 delaminated rotator cuff tear patients, 20 (30.8%) showed a partial-thickness delaminated tear and 45 (69.2%) showed a full-thickness delaminated tear. In the
The posterior extension of delamination is summarized in Table II. Posterior extension of delamination into the infraspinatus tendon was more common in full-thickness
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H.-C. Gwak et al.
Figure 3 (A) In full-thickness delaminated tear, intrasubstance cleavage (a) was calculated by measuring the distance of the high transverse signal from the lateral margin of the more retracted layer to the medial margin of high signal between the 2 layers, and the gap between bursal surface and articular surface (b) was calculated by measuring the distance between the lateral margin of bursal and articular layers. (B) In partial-thickness delaminated rotator cuff tear, intrasubstance cleavage (a) was calculated by measuring the distance of the high transverse signal from the lateral margin of the more retracted layer to the medial margin of high signal between the 2 layers, and the gap between articular and bursal layers (b) was calculated by measuring the distance between the most lateral side of torn layer and intact layer.
Figure 4 CT arthrogram 6 months after the operation showed remaining intrasubstance cleavage (left) and no cleavage (right) in anatomic healed cases.
delaminated tears than in partial-thickness delaminated tears, and this difference was statistically significant (P ¼ .0043). Among the 45 cases of full-thickness delaminated tears, 2 patients (4.4%) with extension of the tear into the supraspinatus tendon showed changes from a full-thickness delaminated tear to a partial-thickness delaminated tear, and 12 patients (26.7%) with extension of the tear into the infraspinatus tendon showed changes from a full-thickness delaminated tear to a partial-thickness delaminated tear as the delamination extended posteriorly. There was a statistically significant difference in the change to another type of tear as the delamination extended posteriorly in the fullthickness delaminated tears (P ¼ .0004). Among the 20 cases of partial-thickness delaminated tears, none of the tears changed to another type as the delamination extended posteriorly (Table III).
Radiologic results after arthroscopic rotator cuff repair Among the 65 delaminated tear patients, 62 underwent CT arthrography 6 months postoperatively. Radiologic results after repair are summarized in Table IV. With regard to the presence of cleavage, there were no statistically significant differences in the anatomic healing between the partial- and full-thickness delaminated tears (P ¼ .6855). With regard to the presence of delamination in the partially healed defect, there was no statistically significant difference between the partial- and full-thickness delaminated tears (P ¼ 1.00). There were also no statistically significant differences in the presence of delamination in retears between the partialand full-thickness delaminated tears (P ¼ .5412). All the patients (10 patients; 100%) with partial healing of the defect showed delamination, and 3 of 17 (17.6%)
The delaminated rotator cuff tear
Figure 5
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CT arthrogram 6 months after the operation showed delamination (left) and no delamination (right) in a case of retear.
Table I Gap between articular and bursal layers, intrasubstance gap, and medial extension of delamination in fulland partial-thickness delaminated tears Gap between Intrasubstance Mediolateral size (mm) articular and gap (mm) bursal layers (mm) FT delaminated 10.3 (4.9) tear PT delaminated 9.1 (5.0) tear P value .3859
7.9 (4.3)
18.1 (6.0)
13.6 (5.5)
22.7 (6.3)
.0001
.0084
FT, full thickness; PT, partial thickness.
Table II Involved tendon in full- and partial-thickness delaminated tears FT delaminated tear PT delaminated tear
SST
SST þ IST
P value
24 (36.9%) 18 (27.7%)
21 (32.3%) 2 (3.1%)
.0043
SST, supraspinatus tendon; SST þ IST, supraspinatus tendon þ infraspinatus tendon; FT, full thickness; PT, partial thickness.
retear patients showed delamination. Fourteen patients (82.4%) with retears did not show delamination. There were statistically significant differences in development of delamination between the patients with partial healing of the defect and retear patients (P ¼ .0001) (Table V).
Discussion A delaminated tear is considered a form of degeneration within the tendon and is generally referred to as a
Table III Delaminated tear type change in full- and partialthickness delaminated tears FT delaminated tear Change () Change (þ) Articular Bursal PT delaminated tear Change () Change (þ)
SST
SST þ IST
24 22 2 2 0 18 18 0
21 9 12 10 2 2 2 0
(48.9%) (4.4%)
(90.0%) (0.0%)
P value .0004
(20.0%) (26.7%)
1.00 (10.0%) (0.0%)
SST, supraspinatus tendon; SST þ IST, supraspinatus tendon þ infraspinatus tendon; FT, full thickness; PT, partial thickness. Articular, articular partial-thickness delaminated rotator cuff tear; Bursal, bursal partial-thickness delaminated rotator cuff tear.
horizontal intrasubstance tear, with partial intratendinous fiber retraction.4,6,16,18 Shear stress between the bursal and articular layers seems to play a role in its pathogenesis. In the evaluation of rotator cuff tears that contained a laminated portion, Ellman4 and Sonnabend et al18 both reported a gap between the articular surface layer fibers and the bursal surface fibers. Sonnabend et al18 also found that a portion of the delaminated torn tendon was split and that a synovium-like cellular lining was present in the split area. Likewise, in this study, a gap between the articular and bursal surface layers and an intrasubstance cleavage between the two layers were characteristics of the delaminated rotator cuff tear. MacDougal and Todhunter11 defined a delaminated tear as cleavage tearing >5 mm based on arthroscopic findings. They used this criterion to evaluate the presence of delamination and did not grade the degree or the extent of delamination. In the current study, we divided the delaminated tears into partial-thickness and full-thickness delaminated tears according to the degree of delamination. Moreover, we characterized the extension type of
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H.-C. Gwak et al. Table IV Radiologic outcomes in full- and partial-thickness delaminated tears FT delaminated PT delaminated P tear tear value Anatomic heal Cleavage (þ) Cleavage () Partial heal Delamination Delamination Retear Delamination Delamination
(þ) () (þ) ()
24 17 7 7 7 0 13 3 10
(48.6%) (20.0%) (70.0%) (0.0%) (17.7%) (58.8%)
11 9 (25.7%) 2 (5.7%) 3 3 (30.0%) 0 (0.0%) 4 0 (0.0%) 4 (23.5%)
.6855
1.00
.5412
FT, full thickness; PT, partial thickness.
Table V Presence of delamination in patients with partial healing and retear Delamination (þ) Delamination ()
Partial healing
Retear
P value
10 0
3 14
.0001
delamination as medial extension and posterior extension. The tears with partial delamination showed greater medial extension than those with full delamination in our study. We could not determine the mechanism underlying the difference in the medial extension of delamination between the partial- and full-thickness delaminated tears. However, we think that the mean retraction and cleavage are important factors in repair of delaminated torn tendons. In delaminated tears, the retraction of articular and bursal surface layer is different.11,12,17,18 Thus, there may be tension mismatch while repairing a delaminated tendon. In our study, the mean gap between the articular and bursal layers was 10.3 4.9 mm in the full-thickness delaminated tears and 9.1 5.0 mm in the partial-thickness delaminated tears. However, many cases exceeded the mean value. Preoperative evaluation of this gap will be useful for finding the deeper articular layer operatively and for selecting the appropriate operative repair technique. Moreover, in this study, intrasubstance cleavage extended more medially from the margin of the retracted layer. This means that part of the intrasubstance cleavage may not have closed properly after the rotator cuff repair. Zilber et al22 stated that an infraspinatus intratendinous cleavage does not affect the status of the supraspinatus muscle. However, they also suggested that it may be difficult to ascertain the healing of delamination in infraspinatus tears. This may be the case in this study, with intratendinous cleavage existing medial to the layer of the delaminated tears. Such cleavage might be overlooked if a careful evaluation is not undertaken. This might result in intratendinous tears not healing and expose the tendon to persistent shear stress.
In this study, we also evaluated the posterior extension of delamination. Among the delaminated tears, posterior extension was common in the full-thickness delaminated tears compared with the partial-thickness delaminated tears. Flurin et al5 reported delamination extension into the supraspinatus in 31% of cases and delamination extension into the infraspinatus in 26% of cases. Han et al7 suggested that posterior delamination is detected differently according to the portal used for access. They also noted that the articular surface layer could be missed because it is retracted more than the bursal surface layer. In this study, 21 cases were extended into the infraspinatus. Moreover, among these cases, 12 changed from a full-thickness delaminated tear to a partial-thickness delaminated tear. Ten of 12 cases changed to an articular partial-thickness delaminated tear as the tear extended posteriorly. Such tears might be difficult to find operatively because the torn articular layer is hidden under the intact bursal surface layer. If preoperative MRI is not performed, these delaminated tears might be overlooked on the basis of arthroscopic findings alone. In cases of preoperative suspicion of a torn articular layer, selection of an appropriate portal and debridement of the bursal layer are needed to detect this layer. In this study, we evaluated cuff continuity after repair of the delaminated rotator cuff. Park et al15 suggested that the incidence of retear was 25% in delaminated rotator cuff repair with use of the en mass suture technique. In this study, the incidence of retear and partial healing of the defect was 27.4% and 16.1%, respectively, after en mass repair of the delaminated rotator cuffs. Park et al15 evaluated only massive rotator cuff tears and evaluated the cuff continuity by ultrasound, dividing their findings into healed and retear. In our study, we evaluated the repair of all types of rotator cuff tears, including partial-thickness tears. We evaluated cuff continuity by CT arthrography and divided the cuff continuity into anatomic healing, partially healed defect, and retears. In our study, the retear and partially healed defect cases showed difference in recurring delamination after arthroscopic repair. To the best of our knowledge, no previous literature has described recurring of delamination after rotator cuff repair. Thus, we cannot explain the cause of this finding and compare our results with those of similar studies. However, we speculate that this difference might be due to tension mismatch between the layers after rotator cuff repair, with different tension between the layers after repair potentially leading to partial healing and delamination. Further evaluation will be needed to shed light on this issue. Interestingly, 26 of 35 anatomically healed cases (74.3%) showed remaining intrasubstance cleavage after bone to tendon healing. Park et al15 stated that the en mass operative technique was useful because it unites the delamination and prevents shear force. However, in our study, although we used this technique, intrasubstance cleavage remained in a high proportion of the patients. The
The delaminated rotator cuff tear clinical significance of this finding is unclear. However, this might affect the remaining tendon and long-term clinical outcomes. This study has some limitations. First, we selected only study subjects who underwent MRI and surgery in our institution. In addition, the subjects were selected on the basis of agreement between the radiologist and the authors. Thus, not all delaminated rotator cuff tear repair patients were included in our study. However, the purpose of this study was to evaluate the extension of delamination, and the protocol for shoulder MRI differs, as do MRI machines, depending on the institution. Therefore, when evaluating the extension of delamination, we did not compare magnetic resonance images taken in other institutions. Moreover, although arthroscopy is supposed to be the ‘‘gold standard’’ for detection of delaminated tears, some cases in more medially retracted layers and posteriorly extended tears may be missed in arthroscopic findings. Thus, we double-checked the presence of delamination with arthroscopic and MRI findings. Second, we used radiologic imaging to evaluate the dimension of delamination. As a result, the arthroscopically measured value could not be determined. Thus, these values are not representative of the actual values. Moreover, some tears that may have extended into the infraspinatus might not have been detected because of the slice thickness. However, in real arthroscopic repairs, fraying edges of torn tears are debrided. Therefore, arthroscopically measured values are not representative of the actual values. It is difficult to calculate the dimension of delamination from arthroscopic findings, and the results are not constant. In contrast, although the evaluation of the dimension of delamination in MRI is largely dependent on the slicing cutting angle, this angle is constant; calculation of the dimension is easy, and the results are reproducible. In addition, we used sagittal oblique images as well as coronal oblique images to evaluate the posterior extension of the delamination. This might reduce the bias due to the cutting slice thickness. Third, retears were evaluated by CT arthrography 6 months postoperatively. The postoperative 6-month time is considered too soon to evaluate the continuity of repaired rotator cuff tears. Moreover, CT arthrography has a potential weakness in that bursal-side tears are not detected if contrast material is placed into the joint. However, our aim here was to determine the rate and type of retear. According to the literature,8,9,13 most retears develop in the first 6 months postoperatively, and many studies have reported using postoperative 6-month CT arthrography for the evaluation of the continuity of repaired rotator cuff tears.2,3,21 Further, long-term evaluations of rotator cuff repairs by MRI studies will be needed. Fourth, functional outcomes were not included in this study. Therefore, whether delaminated tears affect clinical outcomes and whether delaminated retear and nondelaminated retears show different clinical outcomes could not be evaluated. Further evaluation and study will be needed to address these issues. Finally, the size of our study group
7 was relatively small, and we could not perform a power analysis. Therefore, the results might be underpowered with regard to differences in the extension of delamination and retear type between full- and partial-thickness delaminated tears. The results should be interpreted with care.
Conclusion The full-thickness delaminated tears showed less medial extension and more posterior extension than the partialthickness delaminated tears. In the full-thickness delaminated tears, changes to articular partial-thickness delaminated tears as the tears extended posteriorly were common. Anatomic healing, partially healed defects, and retears were 53.9%, 15.4%, and 26.2%, respectively. There were differences in the development of delamination between the partially healed defects and retear cases after arthroscopic repair. Moreover, intratendinous cleavage after healing was a common finding. Further studies are needed to determine the clinical relevance of these results.
Disclaimer The authors, their immediate families, and any research foundation with which they are affiliated have not received any financial payments or other benefits from any commercial entity related to the subject of this article.
Acknowledgment This work was supported by the National Research Foundation of Korea (NRF) funded by the Ministry of Education Science and Technology (NRF2012R1A1A1012384).
References 1. Boileau P, Brassart N, Watkinson DJ, Carles M, Hatzidakis AM, Krishnan SG. Arthroscopic repair of full-thickness tears of the supraspinatus: does the tendon really heal? J Bone Joint Surg Am 2005;87:1229-40. http://dx.doi.org/10.2106/JBJS.D.02035 2. Charousset C, Bellaiche L, Kalra K, Petrover D. Arthroscopic repair of full-thickness rotator cuff tears: is there tendon healing in patients aged 65 years or older? Arthroscopy 2010;26:302-9. http://dx.doi.org/ 10.1016/j.arthro.2009.08.027 3. Charousset C, Grimberg J, Duranthon LD, Bellaiche L, Petrover D, Kalra K. The time for functional recovery after arthroscopic rotator cuff repair: correlation with tendon healing controlled by computed tomography arthrography. Arthroscopy 2008;24:25-33. http://dx.doi. org/10.1016/j.arthro.2007.07.023
8 4. Ellman H. Diagnosis and treatment of incomplete rotator cuff tears. Clin Orthop Relat Res 1990:64-74. 5. Flurin PH, Landreau P, Gregory T, Boileau P, Brassart N, Courage O, et al. Arthroscopic repair of full-thickness cuff tears: a multicentric retrospective study of 576 cases with anatomical assessment. Rev Chir Orthop Reparatrice Appar Mot 2005;91:31-42. 6. Fukuda H. The management of partial-thickness tears of the rotator cuff. J Bone Joint Surg Br 2003;85:3-11. http://dx.doi.org/10.1302/ 0301-620X.85B1.13846 7. Han Y, Shin JH, Seok CW, Lee CH, Kim SH. Is posterior delamination in arthroscopic rotator cuff repair hidden to the posterior viewing portal? Arthroscopy 2013;29:1740-7. http://dx.doi.org/10.1016/j. arthro.2013.08.021 8. Iannotti JP, Deutsch A, Green A, Rudicel S, Christensen J, Marraffino S, et al. Time to failure after rotator cuff repair: a prospective imaging study. J Bone Joint Surg Am 2013;95:965-71. http:// dx.doi.org/10.2106/JBJS.L.00708 9. Kluger R, Bock P, Mittlbock M, Krampla W, Engel A. Long-term survivorship of rotator cuff repairs using ultrasound and magnetic resonance imaging analysis. Am J Sports Med 2011;39:2071-81. http://dx.doi.org/10.1177/0363546511406395 10. Lee SY, Lee JK. Horizontal component of partial-thickness tears of rotator cuff: imaging characteristics and comparison of ABER view with oblique coronal view at MR arthrography initial results. Radiology 2002;224:470-6. http://dx.doi.org/10.1148/radiol. 2241011261 11. MacDougal GA, Todhunter CR. Delamination tearing of the rotator cuff: prospective analysis of the influence of delamination tearing on the outcome of arthroscopically assisted mini open rotator cuff repair. J Shoulder Elbow Surg 2010;19:1063-9. http://dx.doi.org/10.1016/j. jse.2009.12.020 12. Matsuki K, Murate R, Ochiai N, Ogino S. Delamination observed in full-thickness rotator cuff tears [in Japanese]. Shoulder Joint (Katakansetsu) 2005;29:603-6.
H.-C. Gwak et al. 13. Miller BS, Downie BK, Kohen RB, Kijek T, Lesniak B, Jacobson JA, et al. When do rotator cuff repairs fail? Serial ultrasound examination after arthroscopic repair of large and massive rotator cuff tears. Am J Sports Med 2011;39:2064-70. http://dx.doi.org/10.1177/ 0363546511413372 14. Papalia R, Franceschi F, Vasta S, Zampogna B, Maffulli N, Denaro V. Single- and double-row repair for rotator cuff tearsdbiology and mechanics. Med Sport Sci 2012;57:122-41. http://dx.doi.org/10.1159/ 000328902 15. Park JY, Lhee SH, Oh KS, Moon SG, Hwang JT. Clinical and ultrasonographic outcomes of arthroscopic suture bridge repair for massive rotator cuff tear. Arthroscopy 2013;29:280-9. http://dx.doi.org/10. 1016/j.arthro.2012.09.008 16. Resnick D. Diagnosis of bone and joint disorders. 4th ed. Philadelphia: Saunders; 2002. p. 3100-2 (ISBN No. 978-0721689210). 17. Sonnabend DH, Watson EM. Structural factors affecting the outcome of rotator cuff repair. J Shoulder Elbow Surg 2002;11:212-8. http://dx. doi.org/10.1067/mse.2002.122272 18. Sonnabend DH, Yu Y, Howlett CR, Harper GD, Walsh WR. Laminated tears of the human rotator cuff: a histologic and immunochemical study. J Shoulder Elbow Surg 2001;10:109-15. 19. Sugaya H, Maeda K, Matsuki K, Moriishi J. Repair integrity and functional outcome after arthroscopic double-row rotator cuff repair. A prospective outcome study. J Bone Joint Surg Am 2007;89:953-60. http://dx.doi.org/10.2106/JBJS.F.00512 20. Walz DM, Miller TT, Chen S, Hofman J. MR imaging of delamination tears of the rotator cuff tendons. Skeletal Radiol 2007;36:411-6. http:// dx.doi.org/10.1007/s00256-006-0265-3 21. Wu XL, Briggs L, Murrell GA. Intraoperative determinants of rotator cuff repair integrity: an analysis of 500 consecutive repairs. Am J Sports Med 2012;40:2771-6. http://dx.doi.org/10.1177/0363546512462677 22. Zilber S, Carillon Y, Lapner PC, Walch G, Nove-Josserand L. Infraspinatus delamination does not affect supraspinatus tear repair. Clin Orthop Relat Res 2007;458:63-9.